HomeMy WebLinkAboutRFP-2025-v2-DBB Damage Repair (signed)
DEPARTMENT OF PUBLIC WORKS
CITY OF DIAMOND BAR
CALIFORNIA
REQUEST FOR PROPOSALS
FOR DESIGN OF
Diamond Bar Boulevard Damage
Repair at Mapache Drive
APRIL 2025
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CITY OF DIAMOND BAR
REQUEST FOR PROPOSALS (RFP)
Date: April 16, 2025
Department: Public Works
Project Type: Diamond Bar Boulevard Damage Repair at Mapache Drive
Proposals Due: May 15, 2025 at 2:00 P.M.
Project Contact: Hal Ghafari, PE, Public Works Manager/Assistant City Engineer
(909) 839-7044 / HGhafari@DiamondBarCA.gov
INTRODUCTION
Incorporated on April 18, 1989, the City of Diamond Bar (“City”) sets against a scenic
mountain backdrop on more than 8,000 acres (12.5 sq. miles) of rolling hills and valleys
in the East San Gabriel Valley region.
Among the amenities that contribute to the high quality of life that is valued by residents
are the family-friendly atmosphere; the well-maintained parks, trails, and roads; top-rated
school Districts; and the unparalleled public safety services which contribute to keeping
Diamond Bar among the safest communities in the region for the past 30 years.
BACKGROUND
An approximate 70ft section of Diamond Bar Boulevard, along the northwest side
between Cold Spring Lane and Crooked Creek Drive, shows visible damage to the
existing public improvements (pavement, curb, gutter, and sidewalk). Recent images of
this damage are provided in Attachment 2.
In March 2024, the City’s geotechnical consultant prepared a report (Attachment 3) to
evaluate the current soil and geologic conditions at this site and to provide geotechnical
design recommendations for mitigating the damage to these public improvements.
TO INTERESTED FIRMS
The City of Diamond Bar is inviting qualified firms to submit proposals for Diamond Bar
Boulevard Damage Repair at Mapache Drive. The purpose of this Request for Proposals
(RFP) is to have a qualified, professional, and responsive firm to provide design services
and develop plans, specifications, and estimates (PS&E) to the City.
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The awarded firm is responsible for incorporating the geotechnical recommendations into
their design. Any further geotechnical work by the geotechnical consultant of record may
be authorized at the City’s discretion.
This contract will be administered by the City’s Public Works Department.
SCOPE OF SERVICES
This scope of services includes, but is not limited to the following tasks:
1. Pre-construction field meeting and general project management.
2. Project research, including utility research to obtain as-built plans and record data.
This will include a review of the Ninyo & Moore March 8, 2024, Geotechnical
Report (see Attachment 2) and other applicable records as necessary.
3. Topographic survey to include limits of the public right-of-way and private property,
and location of existing structures (trees, walls, etc.) within the survey area.
4. Preparation of plans, specifications, and estimates at the 60%, 90%, and 100%
milestones, using City boilerplate templates and standards. All civil plans must be
submitted at a 1” = 20’ scale with 1-foot contours.
a. It is the City’s intention to reference the Standard Specifications for Public
Works Construction (latest edition) and Standard Plans for Public Works
Construction (latest edition) for this project.
b. The Consultant shall provide copies of all referenced standard plans from
other sources.
5. Preparation of the following construction documents:
a. Demolition,
b. Pile Foundations,
c. Grading and Drainage, and
d. Erosion Control.
Note that registered civil and structural engineers are required to stamp and sign
all plans as applicable.
6. Conduct site visits, and coordinate with the City to request any additional
geotechnical work as necessary to prepare the PS&E.
7. Provide assistance during the bidding process. The Consultant shall be responsive
to all inquiries from prospective bidders. Should any changes be required to the
plans and/or specifications during this phase, the Consultant shall make the
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necessary changes and submit in a timely manner to the City and also assist with
the issuance of a bidding addendum.
8. Provide assistance during the construction process. The Consultant shall be
responsive to all inquiries from the awarded contractor. Should any Requests for
Information (RFI) be issued where the plans and/or specifications must be updated
during this phase, the Consultant shall make the necessary changes and submit
in a timely manner to the City and also assist with the issuance of a Change Order.
9. Submittal of as-built plans upon completion of the construction phase.
10. [OPTIONAL, IF DEEMED NECESSARY] Preparation of easement documents for
construction access and maintenance easements for any proposed public
improvements within the limits of private property.
PROPOSAL CONTENT AND FORMAT
1. PROJECT TEAM: Please provide an organizational chart indicating principles and
key project team members. Also, provide resumes of the key personnel involved
with this contract including personnel from sub-consultants (if any). Identify the
experience of the personnel assigned and briefly outline the responsibilities of
each member. If any changes in personnel occur during the contract period, the
consultant shall notify the City and furnish the same required information.
2. FIRM’S EXPERIENCE/REFERENCES: List three (3) public agencies where
similar services are being provided. Provide the following information: agency
name, project manager's name, and services provided.
3. PROJECT UNDERSTANDING: Describe the approach and methods that will be
used to complete the work described in the scope of services. Provide enough
detail to distinguish the various work required for each task. Also, identify any
potential concerns or problems that your firm anticipates during the term of this
contract.
4. SCHEDULE: Provide a proposed schedule to accomplish all of the required tasks.
Be sure to include time for City review/approval milestones.
5. FEE PROPOSAL: Provide a “not-to-exceed” for each year to provide the required
scope of services, and state the assumptions on which the estimates are based.
Also, provide the hourly rates of all personnel assigned to the contract. These rates
may be used to negotiate additional design work at the City’s request.
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6. AGREEMENT: Attachment 1 is a copy of the City’s Consultant Services
Agreement. A statement must be made in the proposal that all terms and
conditions are acceptable. No exceptions to this agreement are allowed.
GENERAL TERMS AND CONDITIONS
1. Issuance of this Request for Proposals (RFP) and receipt of proposals does not
commit the City to award an agreement. The City expressly reserves the right to
postpone the bid opening date for its own convenience, to accept or reject any or
all bids received in response to this RFP, to negotiate with more than one vendor
concurrently, or to cancel all or part of this RFP.
2. The City reserves the right to reduce or revise elements of the scope of work prior
to the award of any agreement. Furthermore, the City reserves the right to reject
any or all proposals submitted; and no representation is made hereby that any
agreement will be awarded pursuant to this Request for Proposals, or otherwise.
All costs incurred in the preparation of the proposal, in the submission of additional
information and/or in any other aspect of a proposal prior to the award of a written
agreement will be borne by the bidder.
3. Proposals shall be submitted on the forms supplied by the City of Diamond Bar
and contained herein.
4. All proposals, bids, and quotes must be typewritten or written in ink. No erasures
will be permitted. Mistakes may be crossed out and corrections made adjacent.
Corrections must be initialed by the person signing the bid.
5. Proposals submitted may be withdrawn by written or email request received by the
City before the hour set for opening. After such hour, it may not be withdrawn.
6. The City reserves the right to reject any or all proposals and to waive any
informality or technical defect in a proposal.
7. All proposals must be signed by a responsible officer or authorized employee of
the firm, giving the firm’s name and address. Obligations assumed by such
signature must be fulfilled.
8. Submissions of a signed bid will be interpreted to mean that the bidder has thereby
agreed to all of the terms and conditions set forth in the bid package.
9. CONTRACT PERIOD: The term of the contract will be until the completion of all
services rendered.
10. INVITATION FOR INTERVIEW (OPTIONAL): Firm(s) selected for further
consideration for all or parts of the tasks in the scope of work may be contacted to
arrange for an interview with City Staff via a virtual meeting platform. Should a firm
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be asked to participate in the interview, the principal and personnel assigned to
the City should be available to discuss the following:
• Major elements of the proposal; and be prepared to answer any questions
raised to clarify in detail, and
• Satisfactory performance on similar past/current work and description of
previously/current related experience for assigned personnel.
11. SELECTION PROCEDURE: Criteria for evaluation of proposals may include, but
need not be limited to, the following:
• Responsiveness and comprehensiveness of proposal.
• Firm’s and assigned personnels’ experience with the City of Diamond Bar
and other public agencies.
• Quality of previous work performed by the firm.
• Resources and fees required to perform the requested services.
• The firm’s comments on the consulting services agreement.
• References.
12. RIGHT TO REJECT ALL PROPOSALS: The City reserves the right to reduce or
revise elements of the scope of work prior to the award of a contract. Furthermore,
the City reserves the right to reject any proposal and may elect to make a decision
without further discussion or negotiation. This solicitation is not to be construed as
a contract of any kind. The City is not liable for any costs or expenses incurred in
the preparation of the proposals. The right to issue supplementary information or
guidelines relating to this request is also reserved by the City. All proposals
submitted to the City in response to this RFP shall become property of the City.
13. FEE PROPOSAL: A fee proposal shall be submitted separately, including a
detailed schedule with all proposed staff, the hours each person will devote to a
given task, and all reimbursable services to complete work described in the
proposed Scope of Service. The fee proposal(s) shall be uploaded on PlanetBids
separately bearing the name, address, and telephone number of the individual or
entity submitting the proposal.
14. INSURANCE: Proof of insurance requirements addressed in the professional
services agreement of this Request for Proposal shall be submitted by the selected
Consultant upon execution of the contract for submittal to the City Council.
The selected Consultant must submit a "Statement Certifying Insurance Coverage"
certifying that the required insurance coverage will be obtained by the Consultant,
and that the Consultant understands said coverage is prerequisite for entering into
an agreement with the City. The Consultant is required to confirm with its insurance
carrier that it can meet all the requirements for insurance. Failure to meet the
insurance regulations as set forth shall result in the Consultant's disqualification.
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15. AGREEMENT: A copy of the City’s consultant services agreement can be found
as Attachment 1. A statement SHALL be made in the proposal that all terms and
conditions including insurance requirements are acceptable.
ATTACHMENTS SCHEDULE
• ATTACHMENT 1 Sample Contract Agreement
• ATTACHMENT 2 Site Exhibit and Recent Conditions
• ATTACHMENT 3 Ninyo & Moore – March 8, 2024 Geotechnical Report
RFP SCHEDULE
• April 16, 2025 Release of RFP
• May 15, 2025 Proposals Due to the City
• May 20-22, 2025 Invitation for Interview (Optional)
• June 2025 Award of Contract
SUBMITTAL OF PROPOSALS
An electronic copy of the proposal, in PDF format, shall be uploaded onto PlanetBids on
or before two o’clock (2:00) P.M. on Thursday, May 15, 2025. Only electronic proposals
will be accepted. Use the link below to register: https://www.diamondbarca.gov/712/RFP-RFQ-
BID-Opportunities.
QUESTIONS
Any questions can be posted within the Q&A Section in PlanetBids. Please post all
questions no later than 4:00 P.M. on May 8, 2025.
Sincerely,
David G. Liu, P.E.
Director of Public Works/City Engineer
ATTACHMENT 1
SAMPLE CONTRACT AGREEMENT
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1614063.1
CONSULTING SERVICES AGREEMENT
Design Professional
THIS AGREEMENT (the "Agreement") is made as of , 2025 by
and between the City of Diamond Bar, a municipal corporation ("City") and
___________, a [Insert the type of entity of the Consultant, e.g., Inc., a California
corporation; a California general partnership; a California limited liability
company; a sole proprietor; etc.] ("Consultant").
1. Consultant's Services.
Subject to the terms and conditions set forth in this Agreement Consultant shall
provide to the reasonable satisfaction of the City the [describe general type, i.e.,
architecture] services set forth in the attached Exhibit "A", which is incorporated herein
by this reference. As a material inducement to the City to enter into this Agreement,
Consultant represents and warrants that it has thoroughly investigated the work and
fully understands the difficulties and restrictions in performing the work. Consultant
represents that it is fully qualified to perform such consulting services by virtue of its
experience and the training, education and expertise of its principals and employees.
Nicholas Delgado, Management Analyst (herein referred to as the “City’s
Project Manager”), shall be the person to whom the Consultant will report for the
performance of services hereunder. It is understood that Consultant shall coordinate its
services hereunder with the City’s Project Manager to the extent required by the City’s
Project Manager, and that all performances required hereunder by Consultant shall be
performed to the satisfaction of the City’s Project Manager and the City Manager
2. Term of Agreement. This Agreement shall take effect ___________, 2025,
and shall continue until unless earlier terminated pursuant to the provisions
herein.
[Optional Language for Extensions] The City Manager shall have the option
to extend this Agreement for [describe extension option, e.g., two (2) additional two
(2) year terms.], subject to the same terms and conditions contained herein, by giving
Consultant written notice of the exercise of this option at least thirty (30) days prior to
the expiration of the initial Term. In the event the City exercises its option to extend the
Term, Consultant's compensation shall be subject to an adjustment upon the effective
date of extension as follows:
Any increase in compensation will be negotiated between the City and the
Consultant, but in no event shall the increase exceed the amount that the
Consumer Price Index ("CPI") for the Los Angeles-Anaheim-Riverside
metropolitan area for the month immediately preceding the Adjustment Date (the
"Index Month") as reported by the Bureau of Labor Statistics of the United States
Department of Labor, has increased over the CPI for the month one year prior to
the Index Month.
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3. Compensation. City agrees to compensate Consultant for each service
which Consultant performs to the satisfaction of City in compliance with the scope of
services set forth in Exhibit "A". Payment will be made only after submission of proper
invoices in the form specified by City. Total payment to Consultant pursuant to this
Agreement shall not exceed [Spell out dollar amount] ($ ) without the prior written
consent of the City. The above not to exceed amount shall include all costs, including,
but not limited to, all clerical, administrative, overhead, telephone, travel and all related
expenses.
4. Payment.
A. As scheduled services are completed, Consultant shall submit to City an
invoice for the services completed, authorized expenses and authorized extra work
actually performed or incurred.
B. All such invoices shall state the basis for the amount invoiced, including
services completed, the number of hours spent, and any extra work performed.
C. City will pay Consultant the amount properly invoiced within 35 days of
receipt, but may withhold 30% of any invoice until all work is completed, which sum
shall be paid within 35 days of completion of the work and receipt of all deliverables .
[Optional to include withhold-typically would if a deliverable was involved, such
as software or a report]
D. Payment shall constitute payment in full for all services, authorized costs
and authorized extra work covered by that invoice.
5. Change Orders. No payment for extra services caused by a change in
the scope or complexity of work, or for any other reason, shall be made unless and until
such extra services and a price therefore have been previously authorized in writing and
approved by the City Manager or his designee as an amendment to this Agreement.
The amendment shall set forth the changes of work, extension of time , if any, and
adjustment of the fee to be paid by City to Consultant.
6. Priority of Documents. In the event of any inconsistency between the
provisions of this Agreement and any attached exhibits, the provisions of this
Agreement shall control. [If more than one exhibit, determine if one should control
over other, i.e. City's Request for Proposal, Consultant Proposal. Language
would be along the following lines: "In the event of any inconsistency between
this Agreement and the attached exhibits, the following order of precedence shall
apply: (a) This Agreement; (b) The City's Request for Proposal, dated _____; and
(c) Consultant's Proposal dated ______.]
7. Status as Independent Contractor.
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A. Consultant is, and shall at all times remain as to City, a wholly
independent contractor. Consultant shall have no power to incur any debt, obligation, or
liability on behalf of City or otherwise act on behalf of City as an agent. Neither City nor
any of its agents shall have control over the conduct of Consultant or any of
Consultant's employees, except as set forth in this Agreement. Consultant shall not, at
any time, or in any manner, represent that it or any of its agents or employees are in
any manner agents or employees of City.
B. Consultant agrees to pay all required taxes on amounts paid to Consultant
under this Agreement, and to indemnify and hold City harmless from any and all taxes,
assessments, penalties, and interest asserted against City by reason of the
independent contractor relationship created by this Agreement. In the event that City is
audited by any Federal, State agency, including the Public Employee Retirement
System, regarding the independent contractor status of Consultant and the audit in any
way fails to sustain the validity of a wholly independent contractor relationship between
City and Consultant, its employees or subconsultants, then Consultant agrees to
reimburse City for all costs, including accounting and attorney's fees, arising out of such
audit and any appeals relating thereto.
C. Consultant shall fully comply with Workers' Compensation laws
regarding Consultant and Consultant's employees. Consultant further agrees to
indemnify and hold City harmless from any failure of Consultant to comply with
applicable Worker's Compensation laws.
D. Consultant shall, at Consultant’s sole cost and expense fully secure
and comply with all federal, state and local governmental permit or licensing
requirements, including but not limited to a business license with the City of Diamond.
E. In addition to any other remedies it may have, City shall have the
right to offset against the amount of any fees due to Consultant under this Agreement
any amount due to City from Consultant as a result of Consultant's failure to promptly
pay to City any reimbursement or indemnification required by this Agreement or for any
amount or penalty levied against the City for Consultant’s failure to comply with this
Section.
8. Standard of Performance. Consultant shall perform all work at the
standard of care and skill ordinarily exercised by members of the profession under
similar conditions and represents that it and any subcontractors it may engage, possess
any and all licenses which are required to perform the work contemplated by this
Agreement and shall maintain all appropriate licenses during the performance of the
work.
9. Indemnification. To the maximum extent permitted by Civil Code section
2782.8, Consultant shall defend, indemnify and hold harmless City, its officers, officials,
employees and volunteers ("Indemnitees") from and against all liability, loss, damage,
expense, cost (including without limitation reasonable attorneys' fees, expert fees and
all other costs and fees of litigation) of every nature arising out of or in connection with:
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(1) Any and all claims under Worker’s Compensation acts and other employee
benefit acts with respect to Consultant’s employees or Consultant’s contractors;
(2) Any and all claims arising out of Consultant's performance of work hereunder
or its failure to comply with any of its obligations contained in this Agreement. Should
City in its sole discretion find Consultant’s legal counsel unacceptable, then Consultant
shall reimburse the City its costs of defense, including without limitation reasonable
attorneys' fees, expert fees and all other costs and fees of litigation. The Consultant
shall promptly pay any final judgment rendered against the Indemnitees. Except for the
Indemnitees, this Agreement shall not be construed to extend to any third -party
indemnification rights of any kind; and
(3) Any and all claims for loss, injury to or death of persons or damage to
property caused by the negligent professional act or omission in the performance of
professional services pursuant to this Agreement.
(4) The Consultant's obligations to indemnify, defend and hold harmless the City
shall survive termination of this Agreement.
10. Insurance.
A. Consultant shall at all times during the term of this Agreement carry,
maintain, and keep in full force and effect, with an insurance company authorized to do
business in the State of California and approved by the City the following insurance:
(1) a policy or policies of broad-form comprehensive general liability
insurance written on an occurrence basis with minimum limits of $1,000,000.00
combined single limit coverage against any injury, death, loss or damage as a result of
wrongful or negligent acts by Consultant, its officers, employees, agents, and
independent contractors in performance of services under this Agreement;
(2) property damage insurance with a minimum limit of $500,000.00 per
occurrence;
(3) automotive liability insurance written on an occurrence basis covering
all owned, non-owned and hired automobiles, with minimum combined single limits
coverage of $1,000,000.00;
(4) Worker's Compensation insurance when required by law, with a
minimum limit of $500,000.00 or the amount required by law, whichever is greater;
[Note: Does not apply to a sole proprietor, i.e., a Consultant with no employees
but can leave in as it states "when required by law."] and
(5) Professional liability insurance covering errors and omissions arising
out of the performance of this Agreement with a combined single limit of $1,000,000. If
such insurance is on a claims’ made basis, Consultant agrees to keep such insurance in
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full force and effect for at least five years after termination or date of completion of this
Agreement.
B. The City, its officers, employees, agents, and volunteers shall be named
as additional insureds on the policies as to comprehensive general liability, property
damage, and automotive liability. The policies as to comprehensive general liability,
property damage, and automobile liability shall provide that they are primary, and that
any insurance maintained by the City shall be excess insurance only. [If Consultant's
work does not require Consultant to come onto City property except for perhaps
site visits and meetings, City can be flexible with insurance, including need to be
additional insureds and with cancellation provision in Section 10.C below. If
Consultant works off-site and simply delivers a report or product, insurance may
be waived altogether, except for Workers' Compensation]
C. All insurance policies shall provide that the insurance coverage shall not
be non-renewed, canceled, reduced, or otherwise modified (except through the addition
of additional insureds to the policy) by the insurance carrier without the insurance carrier
giving City ten (10) day's prior written notice thereof. Consultant agrees that it will not
cancel, reduce or otherwise modify the insurance coverage and in the event of any of
the same by the insurer to immediately notify the City.
D. All policies of insurance shall cover the obligations of Consultant pursuant
to the terms of this Agreement and except for professional liability insurance, shall be
issued by an insurance company which is authorized to do business in the State of
California or which is approved in writing by the City; and shall be placed have a current
A.M. Best's rating of no less than A-, VII. In the case of professional liability insurance,
such coverage shall be issued by companies either licensed or admitted to conduct
business in the State of California so long as such insurers possesses the
aforementioned Best's rating.
E. Consultant shall submit to City (1) insurance certificates indicating
compliance with the minimum insurance requirements above, and (2) insurance policy
endorsements or a copy of the insurance policy evidencing the additional insured
requirements in this Agreement, in a form acceptable to the City.
F. Self-Insured Retention/Deductibles. All policies required by this
Agreement shall allow City, as additional insured, to satisfy the self-insured retention
(“SIR”) and/or deductible of the policy in lieu of the Consultant (as the named insured)
should Consultant fail to pay the SIR or deductible requirements. The amount of the
SIR or deductible shall be subject to the approval of the City. Consultant understands
and agrees that satisfaction of this requirement is an express condition precedent to the
effectiveness of this Agreement. Failure by Consultant as primary insured to pay its SIR
or deductible constitutes a material breach of this Agreement. Should City pay the SIR
or deductible on Consultant’s due to such failure in order to secure defense and
indemnification as an additional insured under the policy, City may include such
amounts as damages in any action against Consultant for breach of this Agreement in
addition to any other damages incurred by City due to the breach.
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G. Subrogation. With respect to any Workers' Compensation Insurance or
Employer's Liability Insurance, the insurer shall waive all rights of subrogation and
contribution it may have against the Indemnitees.
H. Failure to Maintain Insurance. If Contractor fails to keep the insurance
required under this Agreement in full force and effect, City may take out the necessary
insurance and any premiums paid, plus 10% administrative overhead, shall be paid by
Consultant, which amounts may be deducted from any payments due Consultant.
I. Consultant shall include all subcontractors, if any, as insureds under its
policies or shall furnish separate certificates and endorsements for each subcontractor
to the City for review and approval. All insurance for subcontractors shall be subject to
all of the requirements stated herein.
11. Confidentiality. Consultant in the course of its duties may have access
to confidential data of City, private individuals, or employees of the City. Consultant
covenants that all data, documents, discussion, or other information developed or
received by Consultant or provided for performance of this Agreement are deemed
confidential and shall not be disclosed by Consultant without written authorization by
City. City shall grant such authorization if disclosure is required by law. All City data
shall be returned to City upon the termination of this Agreement. Consultant's covenant
under this section shall survive the termination of this Agreement. Notwithstanding the
foregoing, to the extent Consultant prepares reports of a proprietary nature specifically
for and in connection with certain projects, the City shall not, except with Consultant's
prior written consent, use the same for other unrelated projects.
12. Ownership of Materials. Except as specifically provided in this
Agreement, all materials provided by Consultant in the performance of this Agreement
shall be and remain the property of City without restriction or limitation upon its use or
dissemination by City. Consultant may, however, make and retain such copies of said
documents and materials as Consultant may desire.
13. Maintenance and Inspection of Records. In accordance with generally
accepted accounting principles, Consultant and its subcontractors shall maintain
reasonably full and complete books, documents, papers, accounting records, and other
information (collectively, the “records”) pertaining to the costs of and completion of
services performed under this Agreement. The City and any of their authorized
representatives shall have access to and the right to audit and reproduce any of
Consultant's records regarding the services provided under this Agreement. Consultant
shall maintain all such records for a period of at least three (3) years after termination or
completion of this Agreement. Consultant agrees to make available all such records for
inspection or audit at its offices during normal business hours and upon three (3) days'
notice from the City, and copies thereof shall be furnished if requested.
14. Conflict of Interest.
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A. Consultant covenants that it presently has no interest and shall not
acquire any interest, direct or indirect, which may be affected by the services to be
performed by Consultant under this Agreement, or which would conflict in any manner
with the performance of its services hereunder. Consultant further covenants that, in
performance of this Agreement, no person having any such interest shall be employed
by it. Furthermore, Consultant shall avoid the appearance of having any interest which
would conflict in any manner with the performance of its services pursuant to this
Agreement.
B. Consultant covenants not to give or receive any compensation,
monetary or otherwise, to or from the ultimate vendor(s) of hardware or software to City
as a result of the performance of this Agreement. Consultant's covenant under this
section shall survive the termination of this Agreement.
15. Termination. The City may terminate this Agreement with or without
cause upon fifteen (15) days' written notice to Consultant. The effective date of
termination shall be upon the date specified in the notice of termination, or, in the event
no date is specified, upon the fifteenth (15th) day following mailing of the notice. In the
event of such termination, City agrees to pay Consultant for services satisfactorily
rendered prior to the effective date of termination. Immediately upon receiving written
notice of termination, Consultant shall discontinue performing services, unless the
notice provides otherwise, except those services reasonably necessary to effectuate the
termination. The City shall be not liable for any claim of lost profits.
16. Personnel/Designated Person. Consultant represents that it has, or will
secure at its own expense, all personnel required to perform the services under this
Agreement. All of the services required under this Agreement will be performed by
Consultant or under its supervision, and all personnel engaged in the work shall be
qualified to perform such services. [If it is important that a specific person perform
the work include the following] Except as otherwise authorized by the City's Project
Manager, [If applicable, name of designated person] shall be the person who
primarily performs the work provided under this Agreement. Except as provided in this
Agreement, Consultant reserves the right to determine the assignment of its own
employees to the performance of Consultant's services under this Agreement, but City
reserves the right in its sole discretion to require Consultant to exclude any employee
from performing services on City's premises.
17. Non-Discrimination and Equal Employment Opportunity.
A. Consultant shall not discriminate as to race, color, creed, religion,
sex, marital status, national origin, ancestry, age, physical or mental handicap, medical
condition, or sexual orientation, in the performance of its services and duties pursuant to
this Agreement, and will comply with all rules and regulations of City relating thereto.
Such nondiscrimination shall include but not be limited to the following: employment,
upgrading, demotion, transfers, recruitment or recruitment advertising; layoff or
termination; rates of pay or other forms of compensation; and selection for training,
including apprenticeship.
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B. Consultant will, in all solicitations or advertisements for employees
placed by or on behalf of Consultant state either that it is an equal opportunity employer
or that all qualified applicants will receive consideration for employment without regard
to race, color, creed, religion, sex, marital status, national origin, ancestry, age, physical
or mental handicap, medical condition, or sexual orientation.
C. Consultant will cause the foregoing provisions to be inserted in all
subcontracts for any work covered by this Agreement except contracts or subcontracts
for standard commercial supplies or raw materials.
18. Time of Completion. Consultant agrees to commence the work provided
for in this Agreement within (5) days of being notified by the City to proceed and to
diligently prosecute completion of the work within ________ (__) calendar days from
such date or as may otherwise be agreed to by and between the Project Manager and
the Consultant. [Optional to include time of completion, but if it is important for
City to have the work done within a specific time include.]
19. Time Is of the Essence. Time is of the essence in this Agreement.
Consultant shall do all things necessary and incidental to the prosecution of
Consultant's work.
20. Liquidated Damages. Consultant shall pay City, or have withheld from
monies due it, as liquidated damages, the sum of _______ Dollars ($___) per day for
each and every calendar day's delay in finishing the work within the time specified,
including any written extensions which may be granted, in writing, in accordance with
this Agreement. [Optional, include in situations in which untimely delivery of a
product or service would interfere with City's ability to serve its constituents or
cause project delay. Must have Sections 18 and 19 above to include.]
21. Delays and Extensions of Time. Consultant's sole remedy for delays
outside its control shall be an extension of time. No matter what the cause of the delay,
Consultant must document any delay and request an extension of time in writing at the
time of the delay to the satisfaction of City. Any extensions granted shall be limited to
the length of the delay outside Consultant’s control. If Consultant believes that delays
caused by the City will cause it to incur additional costs, it must specify, in writing, why
the delay has caused additional costs to be incurred and the exact amount of such cost
within 10 days of the time the delay occurs. No additional costs can be paid that
exceed the not to exceed amount absent a written amendment to this Agreement. In no
event shall the Consultant be entitled to any claim for lost profits due to any delay,
whether caused by the City or due to some other cause.
22. Assignment. Consultant shall not assign or transfer any interest in this
Agreement nor the performance of any of Consultant's obligations hereunder, without
the prior written consent of City, and any attempt by Consultant to so assign this
Agreement or any rights, duties, or obligations arising hereunder shall be void and of no
effect.
9 Professional Services - Design
1614063.1
23. Compliance with Laws. Consultant shall comply with all applicable laws,
ordinances, codes and regulations of the federal, state, and local governments.
24. Non-Waiver of Terms, Rights and Remedies. Waiver by either party of
any one or more of the conditions of performance under this Agreement shall not be a
waiver of any other condition of performance under this Agreement. In no event shall
the making by City of any payment to Consultant constitute or be construed as a waiver
by City of any breach of covenant, or any default which may then exist on the part of
Consultant, and the making of any such payment by City shall in no way impair or
prejudice any right or remedy available to City with regard to such breach or default.
25. Attorney's Fees. In the event that either party to this Agreement shall
commence any legal or equitable action or proceeding to enforce or interpret the
provisions of this Agreement, the prevailing party in such action or proceeding shall be
entitled to recover its costs of suit, including reasonable attorney's fees and costs,
including costs of expert witnesses and consultants.
26. Mediation. Any dispute or controversy arising under this Agreement, or in
connection with any of the terms and conditions hereof, which cannot be resolved by
the parties, may be referred by the parties hereto for mediation. A third party, neutral
mediation service shall be selected, as agreed upon by the parties and the costs and
expenses thereof shall be borne equally by the parties hereto. The parties agree to
utilize their good faith efforts to resolve any such dispute or controversy so submitted to
mediation. It is specifically understood and agreed by the parties hereto that mutual
good faith efforts to resolve the same any dispute or controversy as provided herein,
shall be a condition precedent to the institution of any action or proceeding, whether at
law or in equity with respect to any such dispute or controversy.
26. Notices. Any notices, bills, invoices, or reports required by this
Agreement shall be deemed received on (a) the day of delivery if delivered by hand
during regular business hours or by facsimile before or during regular business hours;
or (b) on the third business day following deposit in the United States mail, postage
prepaid, to the addresses heretofore set forth in the Agreement, or to such other
addresses as the parties may, from time to time, designate in writing pursuant to the
provisions of this section.
“CONSULTANT” “CITY”
City of Diamond Bar
21810 Copley Drive
Diamond Bar, CA 91765-4178
Attn.: Attn.: _______________
Phone: Phone:
E-Mail: E-mail:
10 Professional Services - Design
1614063.1
28. Governing Law. This Agreement shall be interpreted, construed and
enforced in accordance with the laws of the State of California.
29. Counterparts. This Agreement may be executed in any number of
counterparts, each of which shall be deemed to be the original, and all of which together
shall constitute one and the same instrument.
30. Entire Agreement. This Agreement, and any other documents
incorporated herein by reference, represent the entire and integrated agreement
between Consultant and City. This Agreement supersedes all prior oral or written
negotiations, representations or agreements. This Agreement may not be amended,
nor any provision or breach hereof waived, except in a writing signed by the parties
which expressly refers to this Agreement. Amendments on behalf of the City will only
be valid if signed by a person duly authorized to do so under the City's Purchasing
Ordinance.
IN WITNESS of this Agreement, the parties have executed this Agreement
as of the date first written above.
"Consultant" "City"
[Insert Full Name of Consultant] CITY OF DIAMOND BAR
By: By:
Printed Name: Dan Fox, City Manager
Title:
By: ATTEST:
Printed Name:
Title:
Kristina Santana, City Clerk
Approved as to form:
By:
Omar Sandoval, City Attorney
*NOTE: If Consultant is a corporation, the City requires the following signature(s):
-- (1) the Chairman of the Board, the President or a Vice-President, AND (2) the Secretary,
the Chief Financial Officer, the Treasurer, an Assistant Secretary or an Assistant
Treasurer. If only one corporate officer exists or one corporate officer holds more than
one corporate office, please so indicate. OR
11 Professional Services - Design
1614063.1
-- The corporate officer named in a corporate resolution as authorized to enter into this
Agreement. A copy of the corporate resolution, certified by the Secretary close in time to
the execution of the Agreement, must be provided to the City.
ATTACHMENT 2
SITE EXHIBIT AND RECENT CONDITIONS
ATTACHMENT 3
GEOTECHNICAL REPORT
PREPARED BY NINYO & MOORE
MARCH 8, 2024
Geotechnical Evaluation
Diamond Bar Boulevard Damage
Diamond Bar Boulevard at Mapache Drive
Diamond Bar, California
City of Diamond Bar
21810 Copley Drive | Diamond Bar, California 91765
March 8, 2024 | Project No. 211727002
Geotechnical | Environmental | Construction Inspection & Testing | Forensic Engineering & Expert Witness
Geophysics | Engineering Geology | Laboratory Testing | Industrial Hygiene | Occupational Safety | Air Quality | GIS
475 Goddard, Suite 200 | Irvine, California 92618 | p. 949.753.7070 | www.ninyoandmoore.com
Geotechnical Evaluation
Diamond Bar Boulevard Damage
Diamond Bar Boulevard at Mapache Drive
Diamond Bar, California
Mr. Nicholas Delgado
City of Diamond Bar
21810 Copley Drive | Diamond Bar , California 91765
March 8, 2024 | Project No. 211727002
Michael Rogers, PG, CEG
Principal Geologist
Michael Putt, PG, CEG
Principal Geologist
Sam Guha, PhD, PE, GE
Principal Engineer
MER/MLP/SG/scs
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 i
CONTENTS
1 INTRODUCTION 1
2 SCOPE OF SERVICES 1
3 SITE DESCRIPTION 2
4 SITE OBSERVATIONS 2
5 SUBSURFACE EVALUATION AND LABORATORY TESTING 3
6 GEOLOGIC AND SUBSURFACE CONDITIONS 3
6.1 Regional Geologic Setting 3
6.2 Site Development 4
6.3 Subsurface Conditions 4
6.3.1 Slough 5
6.3.2 Fill 5
6.3.3 Colluvium/Na tural Soil 5
6.4 Groundwater 5
7 CONCLUSIONS 5
8 RECOMMENDATIONS 6
8.1 Earthwork 7
8.1.1 Construction Plan Review and Pre -Construction Conference 7
8.1.2 Clearing and Site Preparation 7
8.1.3 Fill Material 7
8.1.4 Sidewalk Subgrade Preparation, Fill Placement and Compaction 8
8.2 CIDH Piles 8
8.2.1 Design Considerations for CIDH Piles 9
8.2.2 Construction Considerations for CIDH Piles 9
8.3 Sidewalk Construction 11
8.4 Corrosivity 11
8.5 Concrete 11
9 CONSTRUCTION OBSERVATION 12
10 LIMITATIONS 13
11 REFERENCES 14
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 ii
FIGURES
1 – Site Location
2 – Geotechnical Plan
3 – Regional Geology
4 – Cross Section A-A’
APPENDICES
A – Boring & Test Pit Logs
B – Laboratory Testing
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 1
1 INTRODUCTION
In accordance with your request and authorization, we have performed a geotechnical evaluation
of damage that occurred to the sidewalk along the northwest side of Diamond Bar Boulevard
above the Mapache Drive cul-de-sac in the City of Diamond Bar, California (Figure 1). The
purpose of this study was to evaluate the soil and geologic conditions at the site and to provide
geotechnical design recommendations for mitigating the damage to the city improvements. This
report presents our findings, conclusions, and recommendations.
2 SCOPE OF SERVICES
Our scope of services included the following:
• Initial reconnaissance of the site and damage conducted with the City of Diamond Bar
personnel on August 18, 2023.
• Review of background data for the site, including topographic and geologic maps, seismic
hazard references, published geotechnical literature, and historical aerial photographs.
• Analysis of the original geotechnical plan and details associated with development of
residential tract below Diamond Bar Boulevard provided by the City of Diamond Bar.
• Site reconnaissance on November 14, 2023, to evaluate the site conditions and mark the
proposed boring and test pit locations for utility clearance with Underground Service Alert.
• Subsurface exploration on November 29, 2023, consisting of drilling one 3-inch diameter
boring with a hand auger to a depth of approximately 16.5 feet in the sidewalk area of
Diamond Bar Boulevard. The subsurface exploration also included excavation of two hand -
dug test pits on the rear slope of 21221 Mapache Drive descending from Diamond Bar
Boulevard. The boring and test pits were logged by representatives from our firm, and bulk
and relatively undisturbed soil samples were collected at selected depths for laboratory
testing.
• Laboratory testing of selected samples to evaluate in-place moisture content and dry density,
Atterberg limits, consolidation characteristics, direct shear strength, and soil corrosivity.
• Data compilation and engineering analysis of the information obtained from our background
review, subsurface evaluation, and laboratory testing. Our analysis included preparation of a
geologic cross section to delineate the subsurface conditions.
• Evaluation of repair concepts and discussion with the City of Diamond Bar representatives.
• Preparation of this geotechnical report presenting our findings, conclusions, and geotechnical
design and construction recommendations to mitigate the damage that occurred to the city
improvements at the subject site.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 2
3 SITE DESCRIPTION
The damaged sidewalk is located along the northwest side of Diamond Bar Boulevard southeast
of the Mapache Drive cul-de-sac (Figure 2). At this location, Diamond Bar Boulevard is situated
approximately 25 to 30 feet above the single-family residential properties on Mapache Drive. The
Diamond Bar Boulevard right-of-way is approximately 100 feet wide and consists of two northeast-
bound and two southwest-bound lanes divided by an approximately 15-foot-wide landscaped
median. The roadway includes bicycle lanes and a sidewalk on both sides. The sidewalk along
the northwest side of the boulevard is approximately 8 feet wide.
An approximately 5 to 6-foot-high concrete masonry unit (CMU) block wall is located along the
edge of the sidewalk on the northwest side of Diamond Bar Boulevard. We have been informed
that the wall is owned by the private residential tract adjacent to the city right-of-way. An
approximately 25 to 30-foot-high slope descends below the sidewalk and CMU wall to the private
residence at 21221 Mapache Drive (Figure 2). The slope is inclined at a slope ratio of
approximately 1.5:1 (horizontal to vertical). The slope is covered with a moderate growth of grass.
4 SITE OBSERVATIONS
The observed damage to the improvements on the northwest side of Diamond Bar Boulevard
consists of settlement, cracking and deflection of a section of sidewalk and curb encompassing
an area approximately 70 feet long, as illustrated on Figure 2. The sidewalk panels in the affected
area were observed to be deflected and tilted toward the descending slope up to approximately
7 degrees from horizontal. Sidewalk panels were offset up to approximately 3 inches across
cracks and across the joint between the sidewalk and curb. The sidewalk showed indications of
recent ongoing offset (down-drop) between our site visits on August 18 and November 28, 2023.
The CMU block wall adjacent to the sidewalk showed indications of settlement and deflection in
the downslope direction. There is a visible sag in the wall alignment around the middle of the
damaged area up to approximately 2 degrees from horizontal. Sections of the wall adjacent to the
damaged sidewalk area had been re-built in the past, as indicated by variations in the block and
stair-stepped pattern of block repair. A perpendicular portion of the CMU wall for a tree well that
extends further toward the descending slope was observed to be separated approximately 8
inches and tilted approximately 82 degrees toward the descending slope.
Ground fissures up to 2 inches wide were observed on the descending slope below the damaged
sidewalk area. The ground fissures are tension cracks that are indicative of sloughing and
slumping of the surficial soils on the slope. Growth of phreatophyte grass was observed at the toe
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 3
of slope on the property at 21221 Mapache Drive. The owner of the property reported that
groundwater seepage is observed along the toe of the slope (and adjacent neighbors’ slopes)
during the rainy season. Groundwater was observed in our test pit excavated at the base of the
slope.
5 SUBSURFACE EVALUATION AND LABORATORY TESTING
Subsurface exploration was conducted at the site on November 29, 2023. The exploration
consisted of the drilling, logging, and sampling of one 3-inch-diameter boring (boring B-1) within
the affected sidewalk area. The concrete sidewalk was cored with a coring machine and the soil
boring was performed with a hand auger. The boring was advanced to a depth of approximately
16.5 feet. Our exploration also included the excavation, logging and sampling of two exploratory
test pits on the slope of 21221 Mapache Drive below the damaged sidewalk area. The test pits
(TP-1 and TP-2) were excavated with hand tools to depths of approximately 5.0 and 4.5 feet,
respectively.
The boring and test pits were logged by representatives from our firm. Bulk and relatively
undisturbed soil samples were collected from the boring and test pits for laboratory testing. The
approximate locations of the boring and test pits are shown on Figure 2. Logs of the exploratory
boring and test pits are presented in Appendix A.
Laboratory testing of representative soil samples included tests to evaluate in -place moisture
content and dry density, Atterberg limits, consolidation characteristics, direct shear strength, and
soil corrosivity. The results of the in-situ moisture content and dry density are presented on the
boring and test pit logs in Appendix A. The remaining laboratory test results are presented in
Appendix B.
6 GEOLOGIC AND SUBSURFACE CONDITIONS
6.1 Regional Geologic Setting
The site is located within the Northeastern block of the Los Angeles Basin in the Transverse
Ranges geomorphic province of southern California (Norris and Webb, 1990). This structural
geologic block is bounded by the Whittier fault zone to the southwest and Chino-Central Avenue
fault to the east. The Puente Hills and Chino Hills extend eastward across the province north of
the Whittier fault zone. Diamond Bar is situated at the eastern end of the Puente Hills. This area
of the Puente Hills is underlain by Tertiary period Monterey formation, a sedimentary rock
formation generally consisting of alternating sandstone and shale units.
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Regional geologic maps indicate that the project site on Diamond Bar Boulevard is underlain by
the Soquel Sandstone member of the Monterey formation (Figure 3). This unit is described as a
bedded sandstone that is locally coarse and pebbly and includes minor silty clay shale (Dibblee
and Ehrenspeck, 2001). The regional bedding structure in the vicinity of the site generally consists
of a northeasterly trending strike and northwesterly dip of 10 to 15 degrees (Figure 3).
The nearest active fault to the site is the Whittier fault (Elsinore fault zone) located approximately
2.5 miles to the southwest [United States Geological Survey (USGS), 2024]. The site is not
located in a State of California Seismic Hazard Zone for liquefaction or earthquake -induced
landslide potential (CGS, 2005b).
6.2 Site Development
Based on review of background documents and historical aerial photographs, Diamond Bar
Boulevard was constructed in the early 1960s. Geologic mapping conducted for the development
of Diamond Bar Boulevard at the subject site indicated that shale beds along the alignment had
a northwesterly trending strike and were dipping between 14 and 18 degrees to the northwest
(Merriam, R., 1961). This bedding orientation presented an adverse “out-of-slope” bedding
condition for the construction of the slope between Diamond Bar Boulevard and the residential
tract below (to the northwest). As such, it is our understanding that a buttress fill was designed to
support the northwesterly descending slope below Diamond Bar Boulevard.
Details of the buttress fill design indicate that a Type “2” buttress fill was designed for the slope at
the subject site location. The Type 2 buttress detail included construction of a 1.5:1 compacted fill
slope with a keyway 22 feet wide and 3 feet deep at the toe of the slope. Subdrains were shown
on the buttress details to provide an outlet for groundwater that tends to accumulate at the contact
between the fill and the native soil or bedrock. The Type 2 detail showed that the fill at the top of
the buttress extends approximately 12 feet back from the top of slope and under the sidewalk
area of Diamond Bar Boulevard (Donald R. Warren Co., 1962). The original pre-development
topography shown on the 1961 geologic map indicates that the damaged area of Diamond Bar
Boulevard was constructed at the location of a previous natural drainage gulley. Fill soil placed
for the buttress within this area may be deeper than shown on the design plans. Our interpretation
of the subsurface geology and the general configuration of the buttress fill are shown on our Cross
Section A-A’ (Figure 4).
6.3 Subsurface Conditions
The materials encountered during our subsurface exploration at the site include the concrete
sidewalk, slough, fill, and colluvium/natural soil to the total explored depths of up to approximately
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 5
16.5 feet. Generalized descriptions of the materials encountered during our subsurface
exploration are presented below. Detailed descriptions are presented in the boring and test pit
logs in Appendix A. Our interpretation of the subsurface conditions is shown on Cross Section A-A’
(Figure 4).
6.3.1 Slough
Slough was encountered in exploratory test pit TP-1 at the top of the descending slope below
Diamond Bar Boulevard to a depth of approximately 1 foot. The slough generally consisted
of dry, soft, sandy lean clay with rock fragments.
6.3.2 Fill
Fill soils were encountered in each of our exploratory excavations, boring B-1 and test pits
TP-1 and TP-2. Fill was encountered to a depth of approximately 11.5 feet in boring B-1 and
to the total explored depths of approximately 4.5 and 5.0 feet in test pits TP-1 and TP-2,
respectively. The fill generally consisted of moist, medium dense clayey sand, and moist, firm
to stiff sandy lean clay.
6.3.3 Colluvium/Natural Soil
Undifferentiated colluvial or natural soil materials were encountered beneath the fill (below
11.5 feet) in boring B-1 to the total explored depth of approximately 16.5 feet. The colluvium
consisted moist, soft to stiff lean clay.
6.4 Groundwater
Groundwater was encountered in test pit TP-2 at the toe of the slope descending from Diamond
Bar Boulevard at a depth of approximately 4 feet below the ground surface. Groundwater and/or
seepage were not encountered in our exploratory boring on the sidewalk of Diamond Bar
Boulevard. Fluctuations in the level of groundwater at the site will occur due to variations in ground
surface topography, rainfall, subsurface stratification, irrigation practices, and other factors which
may not have been evident at the time of our evaluation.
7 CONCLUSIONS
Our evaluation of the damaged sidewalk area on Diamond Bar Boulevard ha s included review of
geologic background data, including topographic and geologic maps, historical aerial
photographs, and documents pertaining to the site development. We observed the geologic
conditions of the sidewalk area and adjacent descending slope, conducted subsurface exploration
and performed laboratory testing. Based on our geotechnical evaluation, it is our opinion that the
sidewalk along Diamond Bar Boulevard has been affected by movement of the underlying fine-
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grained fill and colluvial soil associated with lateral downslope movement (i.e., slope creep/lateral
fill extension) of the adjacent fill slope. The slope creep has also caused separation, tilting and
settlement of the CMU block wall on the private property adjacent to the sidewalk. Tension cracks
and ground fissures indicative of surficial slope movement were also observed on the descending
slope below the damaged sidewalk.
In our opinion, poor subsurface drainage conditions of the fill buttress on the adjacent slope have
exacerbated the slope creep mechanism. We did not find functioning subdrain outlets for the
buttress slope during our site reconnaissance. Owners of the properties along the base of the
buttress fill have reported noticing groundwater seepage along the toe of the slope. We observed
phreatophytes growing at the base of the slope at 21221 Mapache Drive during our site
investigation, which suggests a persistent presence of water. We also observed perched
groundwater in our exploratory test pit TP-2 at the toe of the buttress slope. These factors are
indications that the fill slope is not well drained. The private property owners or homeowner’s
association should consider maintaining the subdrainage of the slope, and/or install additional
subdrains to mitigate the poor drainage conditions.
In order to mitigate future movement of the subgrade soils affecting the City improvements, we
recommend installation of a pile-supported retaining system consisting of a row of cast-in-drilled-
hole (CIDH) reinforced concrete piles along the outer edge of the sidewalk at the top of the
descending slope. The sidewalk and adjacent CMU wall should be removed to a llow access for
the installation of the piles and for re-building of the damaged improvements afterwards. The
drilled piles should be connected at the top with a grade beam to act as one structural unit. The
reconstructed block wall can be placed on the grade beam for foundation support.
The proposed repairs are intended to mitigate the damage to the improvements on the City of
Diamond Bar property. The CIDH piles will not mitigate the long -term effects of slope creep or
other problems on the adjacent private property. Ongoing movement of the slope is anticipated.
The implemented repairs recommended in this report are not anticipated to have an adverse
effect on the adjacent slope or the subsurface drainage regime in the buttress fill.
8 RECOMMENDATIONS
The recommendations presented in the following sections provide general geotechnical criteria
for repair of the damaged sidewalk on Diamond Bar Boulevard. The recommendations are based
on the results of our subsurface evaluation, laboratory testing, review of referenced geologic
materials, experience in the general vicinity of the project area, and geotechnical analyses. The
proposed work should be performed in conformance with the recommendations presented in this
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 7
report, project specifications, and appropriate agency standards. When construction drawings for
the sidewalk repair have been prepared, they should be provided to Ninyo & Moore for review to
evaluate if they have been prepared in accordance with the recommendations in this report.
8.1 Earthwork
Earthwork at the site is anticipated to consist of demolition of the existing sidewalk and CMU wall
within the area of damage, drilling for CIDH piles and grade beam, and compaction of new
engineered fill for the sidewalk. Recommendations pertaining to earthwork at the site are provided
in the following sections
8.1.1 Construction Plan Review and Pre-Construction Conference
We recommend that the construction plans be submitted to Ninyo & Moore for review to
evaluate conformance to the geotechnical recommendations provided in this report. We
further recommend that a pre-construction conference be held in order to discuss the
recommendations presented in this report. The owner and/or their representative, the
governing agencies’ representatives, the civil engineer, Ninyo & Moore, and the contractor
should be in attendance to discuss the work plan, project schedule, and earthwork
requirements.
8.1.2 Clearing and Site Preparation
Prior to excavation and fill placement, the site should be cleared of existing site
improvements, pavements, surface obstructions, and abandoned utilities. The site should be
stripped of rubble, debris, and vegetation, as well as surface soils containing organic
materials. Existing utilities to remain in place (if any) should be located a nd protected from
damage by construction activities. Obstructions that extend below the finish grade, if any,
should be removed and the resulting holes filled with compacted soil. The materials
generated from the clearing operations should be removed from the site and disposed of at
a legal dump site.
8.1.3 Fill Material
In general, the on-site soils should be suitable for use as compacted fill, provided they are
free of construction/demolition debris, trash, roots, vegetation, deleterious materials, and
contamination. Fill should generally be free of rocks or lumps of material in excess of 4 inches
in diameter. Rocks or hard lumps larger than approximately 4 inches in diameter should be
broken into smaller pieces or should be removed from the site. Also, on-site soil used as fill
will involve moisture-conditioning to achieve appropriate moisture content for compaction.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 8
Import material should consist of clean, non-expansive, granular material, which conforms to
the “Greenbook” for structure backfill. The soil should also be tested for corrosive properties
prior to importing. We recommend that the imported materials satisfy the Caltrans (2021)
criteria for non-corrosive soils (i.e., soils having a chloride concentration of less than 500
parts per million [ppm], a soluble sulfate content of less than approximately 0.15 percent
(1,500 ppm), a pH value of more than 5.5, or an electrical resistivity of more than
1,500 ohm-centimeters). Materials for use as fill should be evaluated by Ninyo & Moore prior
to importing. The contractor should be responsible for the uniformity of import material
brought to the site.
8.1.4 Sidewalk Subgrade Preparation, Fill Placement and Compaction
The subgrade for the new sidewalks should be prepared by scarifying the upper
approximately 8 inches of exposed subgrade, moisture-conditioning to slightly over optimum
moisture content and compacting to 90 percent relative compaction as evaluated by
ASTM D 1557. Additional overexcavation may be appropriate depending on the material s
exposed during construction.
We anticipate that some fill placement may be needed following demolition of the damaged
portions of the existing top-of-slope wall and foundation. Fill should be compacted in
horizontal lifts to a relative compaction of 90 percent or more as evaluated by ASTM D 1557.
The lift thickness for fill soils will vary depending on the type of compaction equipment used
but should generally be placed in horizontal lifts not exceeding 8 inches in loose thickness.
Fill soils should be placed at slightly above the optimum moisture content as evaluated by
ASTM D 1557. Fill placed on sloping ground should be benched into the slope to remove
slough/soft fill to expose relatively firm and unyielding fill . Special care should be taken to
avoid damage to utility lines and foundations when compacting fill and subgrade materials.
Placement and compaction of the fill soils should be in general accordance with the
appropriate governing agencies and good construction practices.
8.2 CIDH Piles
As previously discussed, we recommend installing a row of CIDH reinforced concrete piles (i.e.,
drilled piers) along the outer edge of the sidewalk at the top of the descending slope. The piers
should be drilled in place and should extend to a depth of approximately 10 feet into the Monterey
formation bedrock or 30 feet below the finished subgrade of the sidewalk, whichever is deeper.
We did not encounter bedrock in our boring B-1 up to the explored depth of 16.5 feet. However,
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 9
based on our review of available geologic maps and grading plans, we anticipate that bedrock
will likely be encountered within 20 feet of the ground surface in the area of the damaged sidewalk.
8.2.1 Design Considerations for CIDH Piles
The key design parameters and considerations for the drilled piers are presented below:
• The piers should be 24 inches or more in diameter. The final depth and spacing of the
piers should be evaluated by the project structural engineer based on the estimated total
service (dead and live) and lateral loads. The piers should be installed at a center-to-
center spacing of no less than three diameters.
• The piers should be connected at the top with a reinforced concrete grade beam. The
grade beam should be, at a minimum, 24 inches wide (i.e., no less than the diameter of
the piers) and 24 inches or more deep.
• For the portion of the grade beam resting on the buttress fill between the adjacent piers,
a net allowable bearing capacity of 1,500 pounds per square foot (psf) may be used in
design. This allowable bearing capacity may be increased by one-third when considering
loads of short duration such as wind or seismic forces.
• Based on the guidelines provided by City of Los Angeles Department of Building and
Safety (LADBS, 2014) and our evaluation, a uniform creep-related lateral load of 1,000
psf up to a depth of 20 feet should be assumed to be acting on each of the piers.
• Lateral resistance should be ignored for the portion of the pier above bedrock. A passive
resistance increasing at a rate of 750 psf per foot of depth may be used to evaluate the
lateral resistance for the portion of the pier embedded in bedrock. The passive resistance
may be considered to act over an area with a width of two times the pier diameter.
• The pier and grade beam details should be included in the project plans. The project
plans should be signed and stamped by a professional engineer registered in the state
of California. Ninyo & Moore should be given the opportunity to review the project plans
to check its compliance with design and construction recommendations presented
herein.
8.2.2 Construction Considerations for CIDH Piles
The pier drilling contractor should mobilize equipment of sufficient size and operating
capability to achieve the design embedment length. The excavation technique chosen by the
contractor should not adversely affect the quality or strength of the pier side or end bearing
materials. If refusal is encountered in these materials during actual installation, Ninyo &
Moore should be retained to evaluate the subsurface condition to establish that refusal has
been met with adequate drilling equipment.
It is anticipated that some of the soils at the site may be subject to caving and heaving.
Depending on the depth of the pier and the time of drilling, groundwater may be encountered
during drilling and the contractor should be prepared to advance the pier under such
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 10
conditions. Casing may be needed in the drilled hole to keep the hole from caving and to
reduce water infiltration into the hole. While placing concrete, the casing should be withdrawn
gradually.
The concrete should be placed in the annular space between the steel reinforcing cage and
the drilled-hole surface using the tremie method. Concrete utilized in the pier should be a
fluid mix with sufficient slump so that it will fill the void between the steel reinforcing cage and
the drilled-hole wall. The contractor should take care to reduce enlargement of the excavation
at the tops of the pier, which could result in mushrooming of the pier top.
The pier hole should be cleaned prior to placement of concrete. Care should be taken to
check that the soils at the pier bottom have not been disturbed. The successful advancement
of the drilled hole for the construction of pier will depend largely on the suitability of the drilling
equipment and the skill of the operator. The drilled foundation contractor should make an
effort to reduce the time during which the excavation remains open. The contractor should
schedule the sequence of operations so that the excavation can be finished, the steel
reinforcing cage placed, and the concrete placed within the same work day. The pier
excavation should not be left open overnight. In case of delay in placing concrete within the
drilled hole due to equipment breakdown or other unforeseen circumstances, casing may be
used to maintain the integrity of the hole. While placing concrete, the casing should be
withdrawn gradually.
The pier installation should be observed by Ninyo & Moore to check that, among other things:
1) subsurface conditions are as anticipated, 2) the pier is constructed to the specified size
and length, 3) the pier bottom is clean and competent, 4) the pier is within allowable
tolerances for plumbness, and 5) reinforcements are placed per project specifications. These
items are fundamental to the installation and behavior of the pier. Furthermore, we
recommend the following for the installation of the pier:
• The clear spacing between the steel reinforcing cage and the drilled-hole surface should
be three times the maximum size of the coarse aggregate used in the concrete.
• Centralizers should be installed to keep the steel reinforcing cage positioned per project
specifications.
• If casing is used, a sufficient head of concrete that fills the casing should be used before
pulling the casing.
• The drilled-hole excavation and cleaning should be observed prior to placement of
reinforcing steel or concrete.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 11
Materials testing and inspection services should be performed, including testing of concrete
compressive strength and steel tensile strength tests.
8.3 Sidewalk Construction
The replacement sidewalk may be supported on compacted on-site soils provided the soils are
moisture-conditioned as indicated in the section above. We recommend that the new concrete
sidewalk have a thickness of 4 inches. The sidewalk should be underlain by 4 inches of clean
sand and installed with crack-control joints at an appropriate spacing as designed by the structural
engineer to reduce the potential for shrinkage cracking. Positive drainage should be established
and maintained adjacent to the sidewalk. Drainage should be directed toward the street and not
over the face of the adjacent descending slope. To help mitigate expansive soil movement we
recommend dowels be placed between the new and existing sections of sidewalk and curb.
8.4 Corrosivity
Laboratory testing was performed on a representative soil sample to evaluate pH, electrical
resistivity, water-soluble sulfate content, and chloride content. The soil pH and electrical resistivity
tests were performed in general accordance with California Test Method (CT) 643. Sulfate content
testing was performed in general accordance with CT 417. Chloride content testing was
performed in general accordance with CT 422. The laboratory test results are presented in
Appendix B.
The results of our corrosivity testing indicated a pH level of approximately 8.8, an electrical
resistivity of approximately 1,402 ohm-centimeters, a sulfate content of approximately 40 ppm
(0.004 percent), and a chloride content of approximately 50 ppm, and Based on the laboratory
test results and Caltrans criteria (2021), the project site may be classified as a corrosive site,
which is defined as having earth materials with a pH of less than 5.5, an electrical resistivity of
less than 1,500 ohm-centimeters, chloride concentration of more than 500 ppm, and more than
0.15 percent sulfates (i.e., 1,500 ppm).
8.5 Concrete
Concrete in contact with soil or water that contains high concentrations of water -soluble sulfates
can be subject to premature chemical and/or physical deterioration. The potential for sulfate attack
is negligible for water-soluble sulfate contents in soil ranging from 0.00 to 0.10 percent by weight,
moderate for water-soluble sulfate contents ranging from 0.10 to 0.20 percent by weight, se vere
for water-soluble sulfate contents ranging from 0.20 to 2.00 percent by weight, and very severe
for water-soluble sulfate contents over 2.00 percent by weight. The soil sample tested for this
evaluation, using Caltrans Test Method 417, indicate a wate r-soluble sulfate content of
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 12
approximately 0.004 percent by weight (i.e., 40 ppm). Accordingly, the on-site soils are considered
to have a negligible potential for sulfate attack and Type II cement may be appropriate. However,
due to the potential variability of the on-site soils, consideration should be given to using Type II/V
cement for the project.
In order to reduce the potential for shrinkage cracks in the concrete during curing, we recommend
that the concrete for the proposed improvements, if applicable, be placed with a slump of 4 inches
based on ASTM C 143. The slump should be checked periodically at the site prior to concrete
placement. We further recommend that concrete cover over reinforcing steel for the piles and
grade beams be provided in accordance with the 2022 California Building Code (CBC) guidelines.
The structural engineer should be consulted for additional concrete specifications.
9 CONSTRUCTION OBSERVATION
The recommendations provided in this report are based on our understanding of the proposed
project and our evaluation of the data collected based on subsurface conditions disclosed by
widely spaced exploratory excavations. It is imperative that the interpolated subsurface conditions
be checked by our representative during construction. Observation of the CIDH pile construction
should also be performed by our representative during construction.
During construction, we recommend that the duties of the geotec hnical consultant include, but
not be limited to:
• Observing site clearing, grubbing, and removals.
• Observing sidewalk subgrade preparation and the placement and compaction of fill.
• Evaluating imported materials prior to their use as fill.
• Performing field tests to evaluate fill compaction.
• Field Concrete Deputy Inspection services for inspection of rebar cages and for inspection
during concrete placement.
• Observing drilling of CIDH piles, checking on pile diameter and depth, and cleaning of pile
bottom prior to placement of rebar cages.
• Field ACI Technician services for sampling and testing during concrete placement, including
checking slump, temperature and air content, as well as casting of concrete cylinders.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 13
10 LIMITATIONS
The field evaluation, laboratory testing, and geotechnical analyses presented in this geotechnical
report have been conducted in general accordance with current practice and the standard of care
exercised by geotechnical consultants performing similar tasks in the project area. No warranty,
expressed or implied, is made regarding the conclusions, recommendations, and opinions
presented in this report. There is no evaluation detailed enough to reveal every subsurface
condition. Variations may exist and conditions not observed or described in this report may be
encountered during construction. Uncertainties relative to subsurface conditions can be reduced
through additional subsurface exploration. Additional subsurface evaluation will be performed
upon request.
This document is intended to be used only in its entirety. No portion of the document, by itself, is
designed to completely represent any aspect of the project described herein. Ninyo & Moore
should be contacted if the reader requires additional information or has questions r egarding the
content, interpretations presented, or completeness of this document.
This report is intended for design purposes only. It does not provide sufficient data to prepare an
accurate bid by contractors. It is suggested that the bidders and their g eotechnical consultant
perform an independent evaluation of the subsurface conditions in the project areas. The
independent evaluations may include, but not be limited to, review of other geotechnical reports
prepared for the adjacent areas, site reconnaissance, and additional exploration and laboratory
testing.
Our conclusions, recommendations, and opinions are based on an analysis of the observed site
conditions. If geotechnical conditions different from those described in this report are
encountered, our office should be notified, and additional recommendations, if warranted, will be
provided upon request. It should be understood that the conditions of a site could change with
time as a result of natural processes or the activities of man at the subject site or nearby sites. In
addition, changes to the applicable laws, regulations, codes, and standards of practice may occur
due to government action or the broadening of knowledge. The findings of this report may,
therefore, be invalidated over time, in part or in whole, by changes over which Ninyo & Moore has
no control.
This report is intended exclusively for use by the client. Any use or reuse of the findings,
conclusions, and/or recommendations of this report by parties other than the client is undertaken
at said parties’ sole risk.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024 14
11 REFERENCES
American Concrete Institute, 2014, Building Code Requirements for Structural Concrete (ACI
318-14) and Commentary (ACI 318R-14).
American Society of Civil Engineers (ASCE), 2010, Minimum Design Loads for Building and other
Structures, Standard 7-10.
Bowles, J.E., 1996, Foundation Analysis and Design, Fifth Edition, The McGraw-Hill Companies,
Inc.
California Building Standards Commission, 2022, California Building Code: California Code of
Regulations, Title 24, Part 2, Volumes 1 and 2, based on the 2021 International Building
Code.
California Department of Transportation, 2021, Corrosion Guidelines, Version 3.0, Division
Engineering Services, Materials Engineering and Testing Services, Corrosion Technology
Branch, Version 3.2, dated May.
California Geological Survey (CGS), 2005a, Seismic Hazard Zone Report, Yorba Linda 7.5-Minute
Quadrangle, Los Angeles, Orange and San Bernardino Counties.
California Geological Survey (CGS), 2005b, Seismic Hazard Zones Official Map, Yorba Linda
Quadrangle, 7.5-Minute Series: Scale 1:24,000, dated August 11.
City of Los Angeles Department of Building and Safety (LADBS), 2014, Information Bulletin
P/BC 2014-050, Construction Upon Slopes Steeper Than Two Horizontal to One
Vertical, Dated January 1.
Dibblee, T.W., Ehrenspeck, H.E., 2001, Geologic Map of the Yorba Linda and Prado Dam
Quadrangles (eastern Puente Hills), Los Angeles, Orange, San Bernardino and Riverside
Counties, California., Dibblee Foundation Map DF-75, Scale 1:24,000.
Donald R. Warren Co., 1962, Tract 25991 Buttress Fill, Los Angeles County, California, dated
October 31.
Google Earth, 2024, http://earth.google.com.
Historic Aerials, 2024, https://www.historicaerials.com, accessed January 24.
Merriam, R., 1961, Geology, Tentative Map Tract No. 25991, Los Angeles County, dated
February 10.
Morton, D.M., Miller, F.K., 2006, Geologic Map of the San Bernardino and Santa Ana 30’ x 60’
quadrangles, California, Version 1.0, United States Geological Survey, Scale: 1:100,000.
Ninyo & Moore, 2023, Proposal for Geotechnical Consulting Services, Diamond Bar Boulevard
Distress Evaluation, City of Diamond Bar, California, dated September 12.
Norris, R.M. and Webb, R.W., 1990, Geology of California: John Wiley & Sons.
United States Geological Survey, 2022, Yorba Linda Quadrangles, California, 7.5 Minute Series:
Scale 1:24,000.
United States Geological Survey and California Geological Survey (USGS/CGS), 2024,
Quaternary Fault and Fold Database for the United States, acce ssed January 24, 2024,
https://www.usgs.gov/natural-hazards/earthquake-hazards/faults.
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024
FIGURES
SITE
Geotechnical & Environmental Sciences Consultants
SITE LOCATION
FIGURE 1
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. I REFERENCE: USGS, 2022. 0
FEET
2,000 4,000
DIAMOND BAR BOULEVARD DAMAGE
DIAMOND BAR BOULEVARD AT MAPACHE PLACE
DIAMOND BAR, CALIFORNIA
211727002 I 3/24
N
211727002.dwg_SL 02/12/2024 GK
DIA
M
O
N
D
B
A
R
B
O
U
L
E
V
A
R
DMA
P
A
C
H
E
DR
I
V
E
21221
TP-2
TD=4.5
TP-1
TD=5.0
B-1
TD=16.5
A
A'
Geotechnical & Environmental Sciences Consultants
GEOTECHNICAL PLAN
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. I REFERENCE: GOOGLE EARTH, MAY 13, 2019. 0
FEET
50 100
DIAMOND BAR BOULEVARD DAMAGE
DIAMOND BAR BOULEVARD AT MAPACHE PLACE
DIAMOND BAR, CALIFORNIA
211727002 I 3/24
N
FIGURE 2211727002.dwg_GP 02/12/2024 GKLEGEND
TP-2
TD=4.5
BORING;
TD=TOTAL DEPTH IN FEET
TEST PIT;
TD=TOTAL DEPTH IN FEET
B-1
TD=16.5
A'A CROSS SECTION
DAMAGED AREA
SITE
REGIONAL GEOLOGY
0
DIAMOND BAR BOULEVARD DAMAGE
DIAMOND BAR BOULEVARD AT MAPACHE PLACE
DIAMOND BAR, CALIFORNIA
211727002 I 3/24
OLDER ALLUVIUM
LEGEND
GEOLOGIC CONTACT
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. I REFERENCE: DIBBLEE, 2001.
FEET
2,000 4,000
Qa
Tm N
211727002.dwg_RG 02/12/2024 GKGeotechnical & Environmental Sciences Consultants
Tmss
FIGURE 3
MONTEREY FORMATION;
UNASSIGNED SHALE
MONTEREY FORMATION;
SOQUEL SANDSTONE MEMBER
Tmlv MONTEREY FORMATION;
LA VIDA SHALE MEMBER
700ELEVATION (FEET)690
A
720
740
760
700
690
720
740
760
ELEVATION (FEET)A'
TP-2
TD=4.5
TP-1
TD=5.0
B-1
TD=16.5
N 43° W
21221 MAPACHE DRIVE DIAMOND BAR BOULEVARD
PL
PRE-GRADING (1960)
TOPOGRAPHY
CMU BLOCK WALL
PERCHED
GROUNDWATER
OBSERVED
11/29/23
FILL
MONTEREY FORMATION SANDSTONE
COLLUVIUM/NATURAL SOIL
??
??
SUBDRAIN
SUBDRAIN
?
?
?
SIDEWALK
APPARENT DIP OF BEDDING
SLOUGH
Geotechnical & Environmental Sciences Consultants
CROSS SECTION A-A'
NOTE: DIMENSIONS, DIRECTIONS AND LOCATIONS ARE APPROXIMATE. 0
FEET
20 400
DIAMOND BAR BOULEVARD DAMAGE
DIAMOND BAR BOULEVARD AT MAPACHE PLACE
DIAMOND BAR, CALIFORNIA
211727002 I 3/24
FIGURE 44_211727002.dwg_CS 02/12/2024 GKLEGEND
?GEOLOGIC CONTACT; QUERIED
WHERE INFERRED
GROUND SURFACE
TP-2
TD=4.5
B-1
TD=16.5
PERCHED GROUNDWATER
BORING;
TD=TOTAL DEPTH IN FEET
TEST PIT;
TD=TOTAL DEPTH IN FEET SUBDRAIN LOCATION PER DONALD R. WARREN CO., 1962
SUBDRAIN WAS NOT OBSERVED DURING OUR
SUBSURFACE EXPLORATION
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024
APPENDIX A
Boring & Test Pit Logs
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024
APPENDIX A
BORING & TEST PIT LOGS
Field Procedure for the Collection of Disturbed Samples
Disturbed soil samples were obtained in the field using the following method s.
Bulk Samples
Bulk samples of representative earth materials were obtained from the exploratory boring
and test pits. The samples were bagged and transported to the laboratory for testing.
Field Procedure for the Collection of Relatively Undisturbed Samples
Relatively undisturbed soil samples were obtained in the field using the following method.
The Split-Barrel Knocker Bar Sampler
The sampler, with an external diameter of 3.0 inches, was lined with 1-inch long, thin brass
rings with inside diameter of approximately 2.4 inches. The sampler was manually driven into
the ground with a hammer weighing approximately 35 pounds. The samples were removed
from the sampler barrel in the brass rings, sealed, and transported to the laboratory for
testing.
Soil Classification Chart Per ASTM D 2488
Primary Divisions Secondary Divisions
Group Symbol Group Name
COARSE-
GRAINED
SOILS
more than
50% retained
on No. 200
sieve
GRAVEL
more than
50% of
coarse
fraction
retained on
No. 4 sieve
CLEAN GRAVEL
less than 5% fines
GW well-graded GRAVEL
GP poorly graded GRAVEL
GRAVEL with
DUAL
CLASSIFICATIONS
5% to 12% fines
GW-GM well-graded GRAVEL with silt
GP-GM poorly graded GRAVEL with silt
GW-GC well-graded GRAVEL with clay
GP-GC poorly graded GRAVEL with clay
GRAVEL with
FINES
more than
12% fines
GM silty GRAVEL
GC clayey GRAVEL
GC-GM silty, clayey GRAVEL
SAND
50% or more
of coarse
fraction
passes
No. 4 sieve
CLEAN SAND
less than 5% fines
SW well-graded SAND
SP poorly graded SAND
SAND with
DUAL
CLASSIFICATIONS
5% to 12% fines
SW-SM well-graded SAND with silt
SP-SM poorly graded SAND with silt
SW-SC well-graded SAND with clay
SP-SC poorly graded SAND with clay
SAND with FINES
more than
12% fines
SM silty SAND
SC clayey SAND
SC-SM silty, clayey SAND
FINE-
GRAINED
SOILS
50% or
more passes
No. 200 sieve
SILT and
CLAY
liquid limit
less than 50%
INORGANIC
CL lean CLAY
ML SILT
CL-ML silty CLAY
ORGANIC
OL (PI > 4)organic CLAY
OL (PI < 4)organic SILT
SILT and
CLAY
liquid limit
50% or more
INORGANIC
CH fat CLAY
MH elastic SILT
ORGANIC
OH (plots on or
above “A”-line)organic CLAY
OH (plots
below “A”-line)organic SILT
Highly Organic Soils PT Peat
USCS METHOD OF SOIL CLASSIFICATION
Geotechnical & Environmental Sciences Consultants
Apparent Density - Coarse-Grained Soil
Apparent
Density
Spooling Cable or Cathead Automatic Trip Hammer
SPT (blows/foot)
Modified Split Barrel (blows/foot)
SPT (blows/foot)
Modified Split Barrel (blows/foot)
Very Loose < 4 < 8 < 3 < 5
Loose 5 - 10 9 - 21 4 - 7 6 - 14
Medium
Dense 11 - 30 22 - 63 8 - 20 15 - 42
Dense 31 - 50 64 - 105 21 - 33 43 - 70
Very Dense > 50 > 105 > 33 > 70
Consistency - Fine-Grained Soil
Consis-tency
Spooling Cable or Cathead Automatic Trip Hammer
SPT (blows/foot)
Modified Split Barrel
(blows/foot)
SPT (blows/foot)
Modified Split Barrel (blows/foot)
Very Soft < 2 < 3 < 1 < 2
Soft 2 - 4 3 - 5 1 - 3 2 - 3
Firm 5 - 8 6 - 10 4 - 5 4 - 6
Stiff 9 - 15 11 - 20 6 - 10 7 - 13
Very Stiff 16 - 30 21 - 39 11 - 20 14 - 26
Hard > 30 > 39 > 20 > 26
LIQUID LIMIT (LL), %PLASTICITY INDEX (PI), %0 10
107
4
20
30
40
50
60
70
0 20 30 40 50 60 70 80 90 100
MH or OH
ML or OLCL - ML
Plasticity Chart
Grain Size
Description Sieve
Size Grain Size Approximate
Size
Boulders > 12”> 12”Larger than
basketball-sized
Cobbles 3 - 12”3 - 12”Fist-sized to
basketball-sized
Gravel
Coarse 3/4 - 3”3/4 - 3”Thumb-sized to
fist-sized
Fine #4 - 3/4”0.19 - 0.75”Pea-sized to
thumb-sized
Sand
Coarse #10 - #4 0.079 - 0.19”Rock-salt-sized to
pea-sized
Medium #40 - #10 0.017 - 0.079”Sugar-sized to
rock-salt-sized
Fine #200 - #40 0.0029 -
0.017”
Flour-sized to
sugar-sized
Fines Passing
#200 < 0.0029”Flour-sized and
smaller
CH or OH
CL or OL
;;;;
SM
CL
%XONVDPSOH
0RGLILHGVSOLWEDUUHOGULYHVDPSOHU
1RUHFRYHU\ZLWKPRGLILHGVSOLWEDUUHOGULYHVDPSOHU
6DPSOHUHWDLQHGE\RWKHUV
6WDQGDUG3HQHWUDWLRQ7HVW 637
1RUHFRYHU\ZLWKD637
6KHOE\WXEHVDPSOH'LVWDQFHSXVKHGLQLQFKHVOHQJWKRIVDPSOHUHFRYHUHGLQLQFKHV
1RUHFRYHU\ZLWK6KHOE\WXEHVDPSOHU
&RQWLQXRXV3XVK6DPSOH
6HHSDJH
*URXQGZDWHUHQFRXQWHUHGGXULQJGULOOLQJ
*URXQGZDWHUPHDVXUHGDIWHUGULOOLQJ
0$-250$7(5,$/7<3( 62,/
6ROLGOLQHGHQRWHVXQLWFKDQJH
'DVKHGOLQHGHQRWHVPDWHULDOFKDQJH
$WWLWXGHV 6WULNH'LS
E %HGGLQJ
F &RQWDFW
M -RLQW
I )UDFWXUH
) )DXOW
FV &OD\6HDP
V 6KHDU
EVV %DVDO6OLGH6XUIDFH
VI 6KHDU)UDFWXUH
V] 6KHDU=RQH
VEV 6KHDU%HGGLQJ6XUIDFH
7KHWRWDOGHSWKOLQHLVDVROLGOLQHWKDWLVGUDZQDWWKHERWWRPRIWKHERULQJDEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.BORING LOG EXPLANATION SHEET
BORING LOG
20
0
10
20
30
40
17.8
20.0
21.4
21.8
96.9
105.1
98.1
104.6
SC
CL
CL
CONCRETE:
Approximately 4 inches thick.
FILL:
Yellowish brown, moist, medium dense, clayey SAND; trace gravel.
Grayish brown, moist, firm to stiff, sandy lean CLAY.
COLLUVIUM/NATURAL SOIL:
Dark brown, moist, soft to firm, lean CLAY; iron oxidation streaks.
Medium brown; stiff; calcium carbonate blebs.
Total Depth = 16.5 feet.
Groundwater was not encountered during drilling.
Backfilled with native soil and patched with rapid-set concrete on 11/29/23.
Notes:
Groundwater, though not encountered at the time of drilling, may rise to a higher level due
to seasonal variations in precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based on our interpretations
of published maps and other documents reviewed for the purposes of this evaluation. It is
not sufficiently accurate for preparing construction bids and design documents.
FIGURE A- 1
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 |3/24DEPTH (feet)BulkSAMPLESDrivenBLOWS/FOOTMOISTURE (%)DRY DENSITY (PCF)SYMBOLCLASSIFICATIONU.S.C.S.DESCRIPTION/INTERPRETATION
DATE DRILLED 11/29/23 BORING NO.B-1
GROUND ELEVATION 737' ± (MSL)SHEET 1 OF
METHOD OF DRILLING 4" Hand Auger (Mike's Excavating Service)
DRIVE WEIGHT 35 pounds DROP -
SAMPLED BY RAF LOGGED BY RAF REVIEWED BY MER
1
0
Medium brown; increase in moisture.
Total Depth = 5.0 feet.
No caving.
Groundwater was not encountered.
Backfilled with on-site soils on 11/29/23.
12
FILL:
Light brown, moist, stiff, sandy lean CLAY; mottled; rocky.
Notes:
Groundwater, though not encountered at the time of test pit
excavation, may rise to a higher level due to seasonal variations in
precipitation and several other factors as discussed in the report.
The ground elevation shown above is an estimation only. It is based
on our interpretations of published maps and other documents
reviewed for the purposes of this evaluation. It is not sufficiently
accurate for preparing construction bids and design documents.9
28.9 86.9
5
11
10SCALE7
6
1 inch = 2 feet8
4
3
LOCATION:DRY DENSITY (PCF)2
1 CL
METHOD OF EXCAVATION Hand Tools
BulkDrivenUpper Slope Area - 21221 Mapache Drive
DESCRIPTIONTEST PIT DIAGRAM
CL SLOUGH:
Light brown, dry, soft, sandy lean CLAY; rocky; mottled.CLASSIFICATIONU.S.C.S.DATE EXCAVATED 11/29/23 TEST PIT NO.:TP-1
GROUND ELEVATION 733' ± (MSL) LOGGED BY:MER
Sand ConeDEPTH (FEET)SAMPLESMOISTURE (%)TEST PIT LOG
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
FIGURE A-2
Test Pit
Outline
Slough
Fill
1.5:1 Slope
0
@ 4.0': Perched groundwater.
Light brown to yellowish brown; wet; firm.
Total Depth = 4.5 feet.
No caving.
Groundwater was encountered at approximately 4 feet.
Backfilled with on-site soils on 11/29/23.
12SCALE1 inch = 2 feet11/29/23
GROUND ELEVATION 712' ± (MSL)
DATE EXCAVATED
METHOD OF EXCAVATION Hand Tools
TEST PIT DIAGRAM
CL
4
87.4
6
8
10
1
28.1
9
11
3
5
7
2 CLASSIFICATIONU.S.C.S. TEST PIT NO.:
LOGGED BY:
TP-2
RAF/MER
LOCATION:Toe of Slope - 21221 Mapache Drive
DESCRIPTION
FILL:
Light brown, moist, stiff, sandy lean CLAY; trace gravel, brick and
shale fragments.
Notes:
Groundwater may rise to a level higher than that measured in test pit
due to seasonal variations in precipitation and several other factors as
discussed in the report.
The ground elevation shown above is an estimation only. It is based
on our interpretations of published maps and other documents
reviewed for the purposes of this evaluation. It is not sufficiently
accurate for preparing construction bids and design documents.DRY DENSITY (PCF)MOISTURE (%)DEPTH (FEET)SAMPLESSand ConeBulkDrivenTEST PIT LOG
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
FIGURE A-3
1.5:1 Slope
Test Pit Outline
Perched
Groundwater
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024
APPENDIX B
Laboratory Testing
Ninyo & Moore | Diamond Bar Boulevard Damage, Diamond Bar, California | 211727002 | March 8, 2024
APPENDIX B
LABORATORY TESTING
Classification
Soils were visually and texturally classified in accordance with the Unified Soil Classification
System (USCS) in general accordance with ASTM D 2488. Soil classifications are indicated on
the logs of the exploratory boring and test pits in Appendix A.
In-Place Moisture and Density Tests
The moisture content and dry density of relatively undisturbed samples obtained from the
exploratory boring and test pits were evaluated in general accordance with ASTM D 2937. The
test results are presented on the logs of the exploratory boring and test pits in Appendix A.
Atterberg Limits
Tests were performed on selected representative fine-grained soil samples to evaluate the liquid
limit, plastic limit, and plasticity index in general accordance with ASTM D 4318. These test results
were utilized to evaluate the soil classification in accordance with the USCS. The test results and
classifications are shown on Figure B-1.
Consolidation Tests
Consolidation tests were performed on selected relatively undisturbed soil samples in general
accordance with ASTM D 2435. The samples were inundated during testing to represent adverse
field conditions. The percent of consolidation for each load cycle was recorded as a ratio of the
amount of vertical compression to the original height of the sample. The results of the tests are
summarized on Figures B-2 and B-3.
Direct Shear Test
Direct shear test was performed on a relatively undisturbed sample in general accordance with
ASTM D 3080 to evaluate the shear strength characteristics of the selected material. The sample
was inundated during shearing to represent adverse field conditions. The results are summarized
on Figure B-4.
Soil Corrosivity Tests
Soil pH and minimum resistivity tests were performed on representative samples in general
accordance with CT 643. The sulfate and chloride contents of the selected samples were
evaluated in general accordance with CT 417 and 422, respectively. The results are summarized
on Figure B-5.
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 4318
USCS
(Fraction Finer Than
45
16B-1
B-1
12.0-13.0
No. 40 Sieve)
PLASTICITY
INDEX
CLASSIFICATION
8.0-9.0 2541
USCS
CL
CL
CL
CL
29
16
SYMBOL LOCATION DEPTH (ft)
LIQUID
LIMIT
PLASTIC
LIMIT
CH or OH
CL or OL MH or OH
ML or OLCL - ML
0
10
20
30
40
50
60
0 102030405060708090100PLASTICITY INDEX, PI LIQUID LIMIT, LL
FIGURE B-1
ATTERBERG LIMITS TEST RESULTS
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
211727002 Fig B-1_ATTERBERG @ B-1
Seating Cycle Sample Location B-1
Loading Prior to Inundation Depth (ft) 6.0-7.0
Loading After Inundation Soil Type CL
Rebound Cycle
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 2435
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
FIGURE B-2
211727002 Fig B-2_CONSOLIDATION @ B-1 6.0-7.0
Seating Cycle Sample Location B-1
Loading Prior to Inundation Depth (ft) 16.0-16.5
Loading After Inundation Soil Type CL
Rebound Cycle
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 2435
-4.0
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.1 1.0 10.0 100.0
CONSOLIDATION IN PERCENT OF SAMPLE THICKNESS (%) EXPANSION (%)STRESS IN KIPS PER SQUARE FOOT
CONSOLIDATION TEST RESULTS
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
FIGURE B-3
211727002 Fig B-3_CONSOLIDATION @ B-1 16.0-16.5
PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080
CLAYEY SAND X Ultimate2.0-3.0B-1
Cohesion
(psf)
Friction Angle
(degrees)Soil Type
SC37
38
168
SC
Description Symbol
Sample
Location
222
Depth
(ft)
Shear
Strength
2.0-3.0CLAYEY SAND B-1 Peak
0
500
1000
1500
2000
2500
3000
3500
4000
0 500 1000 1500 2000 2500 3000 3500 4000SHEAR STRESS (PSF)NORMAL STRESS (PSF)
FIGURE B-4
DIRECT SHEAR TEST RESULTS
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
211727002 Fig B-4_DIRECT SHEAR @ B-1 2.0-3.0
1 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 643
2 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 417
3 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 422
(ppm) (%)
CHLORIDE
CONTENT 3
(ppm)
B-1 0.0-5.0
pH 1SAMPLE
DEPTH (ft)
SAMPLE
LOCATION
RESISTIVITY 1
(ohm-cm)
8.8 501,402 40 0.004
SULFATE CONTENT 2
CORROSIVITY TEST RESULTS
DIAMOND BAR BLVD. DAMAGE
DIAMOND BAR, CALIFORNIA
211727002 | 3/24
FIGURE B-5
211727002 Fig B-5_CORROSIVITY @ B-1
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