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HomeMy WebLinkAboutm32974-3 final.pdfQ{ S. E. Meclall & Associates, Inc. Consultants in the Earth Sciences 90066 • 3030 South Bundy Drive, Los Angeles, California 213/390-4079 2168 South Hathaway Street, Santa Ana, California 92705 • 7141546-6602 17231 East Railroad Street, City of Industry, California91748 • 2131964-2313 TRACT 32974 REPLY TO COUNTY OF LOS ANGELES SOIL ENGINEERING REVIEW SHEET AND GEOLOGIC REVIEW SHEET for WEATHERFIELD HOMES W.O. 605 December 13, 1-976 S. E. Medall & Associates, Inc. Consultants in the Earth Sciences j lr 3030 South Bundy Drive, Los Angeles, California 90066.2131390.4079 2168 South Hathaway Street, Santa Ana, California 92705 • 714/546-6602 w, 17231 East Railroad Street, City of Industry, California91748 •2131964-2313 December 13, 1976 W. O. 605 Weatherfield Homes 2130 E. 4th Street Suite 110 Santa Ana, California 92705 Attention: Mr. Glen Brengle Subject: Tract 32974; Reply to County of Los Angeles, Soil Engineering Review Sheet, dated December 3, 1976 and Geologic Review Sheet, dated December 6, 1976. References: 1) Soil Engineering and Geologic Review of Tentative Tract 29053 and 'Tract 32974, County of Los Angeles, by this firm, dated October 4, 1976. 2) Tract 32974; Reply to County of Los Angeles Soil Engineering Review Sheet, dated October 21, 1976 and Geologic Review Sheet, dated October 28, 1976, by this firm, dated November 10, 1976. Gentlemen: The following discussion is offered in reply to the referenced county review sheets. GEOLOGIC REVIEW SHEET Item IA The maximum depth of the Diamond Bar slide in the area influ- ential to tract evaluation is not known for certain. Similarly, Weatherfield Homes Page 2 December 13, -1976 W. o. 605 the lateral limits have not been established. Conflic is in interpretation of depth of slide in the head area exists based on prior consultants evaluation (Slosson and Dr. Merriam). No subsurface work has apparently been done on the slice area itself. What exactly are the limits of the slide with xespect to the proposed development?" The depth of the Diamond Bar landslide in the area influential to Tract 32974 has been delineated by excavating exploratory Borings 5 through 9. The boring logs are attached and their location is shown on.the enclosed geologic maps. These borings were placed along the southerly edge of the Diamond Bar -land- slide in order to determine the depth of the Diamond Bair land- slide and to resolve the question in regards to the previous work of ,Slosson and Merriam as to the possibility of the slide being deeper than they have shown. Our borings were drilled significantly deeper than all borings previously drilledd and indicated that the depth of the Landslide is essentially as pre- viously reported. No indication was found to indicate 'that a deeper slide plane exists. Additionally, the limits caf the southern edge of the Diamond Bar landslide in relation to the proposed tract development has been more clearly shown fon the enclosed grading plans. Geologic Sections M-M', A -A', BB -BB' and AA -AA' have been revised to indicate the results of our S. E. M-9dall & Associales, Inc. Weatherfield Homes December 13, 1976 Page 3 W. O. 605 additional subsurface exploration. Borings 5 and 7 were placed near the entrance road for Tract 32974. Boring 5 was excavated within the Diamond Bar landslide and the depth of the slide was found to be approximately 17 feet in this location. Boring 7 was placed at the location of the entrance road in the canyon bottom and found to contain no slide debris. The results of these additional borings indicate that the slide limits must be at least no closer -to the tract than shown on the enclosed geologic map and possibly farther to the northwest. Boring 6 was placed on the Diamond Bar landslide in the -,vicin- ity of Boring No. 1 drilled by Merriam. Both these borings are indicated on Section A --A'. There was question as to whether Merriam had penetrated the deepest portion of the landslide. Our boring 6 was drilled an additional 20 feet below Merriam's boring and no indication of landslide debris was found below that shown by Merriam. Additionally, our boring 6 confirmed the depth of the landslide as indicated by Merriam in this vicinity. Borings 8 and 9 were drilled near the head of the Diamond Bar landslide. Boring 8 encountered the base of the Diamond Bar landslide at approximately 27 feet. Boxing 9 encountered S. E. Medall & Associates, Inc. Weatherfield Homes Page 4 December 13, 1976 W. O. 605 no slide debris. Boring 8 confirms the depth of Diamond Bar landslide as shown in Boring 5 of Merriam. Item 1B Additional cross Sections AA -AA' and BB -BB' suggest that a fill shear key is needed in the event the Diamond Bar slide moves. For similar reasons, a deeper than recommended shear v kAIT key is suggested in Section A -A' wherein bedrock beneath the landslide on Lots 72 through 75 may be unsupported if the Diamond Bar landslide moves. Furthermore, what recommendations are proposed to ascertain that no water from irrigation from future residences on Lots 70 through 82 building pads will lead to the slide mass via bedding planes and therefore contribute to potential slide instability which could be attributed to this development." A stability analysis was conducted along the natural slope on Section AA --AA'. In this analysis, it was assumed that the Diamond Bar landslide had completely moved away from the natural slope below the proposed pad grades. This assumption in our opinion, is considered totally unlikely, however, for purposes of illustration of the stability of the natural slope, it was assumed. The analysis indicated a safety factor in excess of S. E. Medall & Associates, Inc. weatherfield Homes Page 5 December 13, 1976 W. o. 605 1.5 static and in excess of 1.25 seismic for the natural slope below these graded lots. Therefore, a shear key will not be required as suggested in the geologic review sheet. With respect to Section BB -BB' an analysis was: conducted for the stability of the proposed fill slope indicated. As is r required in all fill slopes above natural areas, an equipment 0, q n width fill key (20' x 3' deep) would have been constructed during;. the normal grading operation. The analysis has taken this into account. Again a safety factor in excess of 1.5 static and 1.25 seismic have been achieved for this slope. In order to prevent hydrostatic build-up at the rear of this fill, buttress drains are recommended. They should be constructed inNaccord- ance with the details previously presented on the grading plan. This equipment width key and subdrain system should be constructed V for the fill slope proposed below Lots 76 through 79. Additionally, Lots 76 through 82 should be undercut 3 feet and replaced as compacted fill in order to minimize infiltration of irrigation waters into and along the underlying bedding planes. The recommendation for undercutting and capping these lots to prevent infiltration of water to bedding planes below is made because this is the standard practice of the profession. The S. E. Medall & Associates, Inc. Weatherfield Homes Page 6 December 13, 1976 W. Q. 6©5 capping of these lots as well as the presence of the house on the lot and the fact that all drainage is being directed toward the streets, away from the natural slope below, will improve drainage of the site. As previously stated and as indicated on the revised Section A --A', the Diamond Bar landslide if it does move will move in a direc- tion other than away from the landslide which is being stabil- ized by the shear key below Lots 72 through 75. Looking at Section A -A' revised, the Diamond Bar landslide would move into the paper rather than away or toward the right of the page. The shear key proposed below Lots 72 through 75 is totally indepen- dent of the Diamond Bar landslide and the landslide below Lots 72 through 75. Bedding beneath this shear key will not be unsupported should the Diamond Bar landslide move due to the fact that the Diamond Bar landslide will not pull away and leave a graben below. I tem 2 Are subdrains also needed for buttress type keys recom- mended by the consultant on Lots 72-82 area." Subdrains are recommended for the shear key below Lots 72. through 75 and the fill slope below Lots 76 through 79. These S. E. Medall & Associates, Inc. Weatherfield Homes Page 7 December 13, IL976 W. O. 605 drains should be constructed in accordance with the standard detail for buttress drains presented on the grading plans. Sub - drains are not recommended for the area below Lots 80 through B2 in that irrigation water will be controlled as indicated in Item 1B above. Item 3 Comply with soil engineering section comments attached,." See reply to. soil engineering review in a later portiorL of this report. Item 4 Complete Item 8 of 10--28--76 review letter regarding adjacent or offsite areas. Additional evaluations covered by this review must be included also." The proposed change in the use of the land by the develcopment of Tract 32974 will not create any adverse' soil or geolcogi.c effects on adjacent properties or offsite areas. Refer to Items 1A, 1B and 2 above for grading adjacent to the Diamond Bar landslide. The proposed grading will not adveresly affect or influence the Diamond Bar landslide. All fills beinY_g placed adjacent to the Diamond Bar landslide are independent of and impose no load upon the Diamond Bar landslide. Additionally, ;.all drainage is being directed away from the Diamond Bar landslide S. E. Medal[ & Associates, Inc. Weatherfield Homes Page 8 December 13, 1976 w. O. 605 by graded pads which will drain away from the slide, or by inter- nal drainage systems in buttress fill slopes. No adverse effects will be created by grading adjacent to Dia- mond Bar Boulevard. All fills being placed along Diamond Bar Boulevard will be sufficiently keyed or buttressed and pose no hazard to Diamond Bar Boulevard. Refer to Revised Section E-E' and Section B-B'. T+-nrn r; Item 9 of the 10-28-76 review must be completed. The "Af slopes" on the geologic map should be corrected. Section. E-E' must be drawn at 40--scale a-t toe of fill area only to show relationship of daylighted bedding in Diamond Bar Boulevard cut slopes to proposed toe of fill slopes. Key to be adequate to prevent surcharging the bedding condition." The cut slope along Diamond Bar Boulevard where daylighted bed- ding is present in the vicinity of Section B-B'was previously analyzed and shown to be stable with the 35' x 3' key at the toe of the slope along Diamond Bar Boulevard. Section E-E'has been redrawn at 40--scale as requested. The stabilization of the existing cut slope in this vicintiy has S. E. Medall & Associates, Inc. Weatherfield Homes Page 9 December 13, 1976 W. O. 605 been modified to indicate a 50-foot wide x 3 foot key to be constructed_at tho..toe_of this existing cut rather than as pre- viously indicated. This will provide adequate protection from failure as indicated by the enclosed calculations. The "Af" slopes previously shown on the geologic maps have been corrected to indicate existing cut slopes. Item 6 Regarding the above report, Item 1D (response to our 10-28-76 review) two reports of Dr. Merriam exist. Both undated, but enclosed in reports of Triad Engineering report of 7-18-71 and 10-16-61." Copies of these reports have been obtained through Triad Engineering, have been reviewed. Item 7 Geologic section CC -CC' area a dip slope condition where a sliver fill is proposed must be analyzed for potential need for a buttress type width and key." The following equation defines the critical height, he above which failure by sliding is likely to occur along a predeter- mined bedding plane: S. E. Medals & Associates, Inc. Weatherfield Homes Page 10 hc e ycos 2 0_ ( tangy: - tan ) December 13, 1976 W. O. 605 This equation also appeared in the Frankian paper previously submitted. in our original analysis, we used the following Yield shear strength parameters: Buttress Fill c = 750 psf 26° 118 Along Bedding c = 200 psf 10, 0 The above shear parameterssuggests that for a planar failure mechanism, the shear parameters along the beading governs. Based on Section CC -CC', the bedding angle is 100. in order to avoid a zero or negative answer for the fooregoing equation for hc, adopt = 90 along the bedding instead of 100. Of course, this is valid and conservative. Accordingly, he 2 200 = 97. 4 feet 0 118 Cos 10 (tan, 10 - tan 9 0> ) The maximum depth of fill above the critical bedding plane pro- jected from the toe of the slope is 40 feet. In other words, the factor of safety for any vertical unit slice above the criti- cal bedding plane is greater than he/ha where ha is the actual height or depth. In brief, minimum factor of safety is as follows: S. E. Medaii & Associates, Inc. Weatherfield Homes Page 11 S.F. = he = 97.4 `-2.44 h 40 a December 13, 1976 W. O. 605 If the factor of safety is plotted against distance from the toe, it will be noted that the former varies from infinity (c-) at the toe of the slope to a minimum of 2.44 at the highest point of the slope and again increase beyond this point to about 6.49 at the right end of Section CC -CC'. This plot suggests that the "sliding blocks" on either side of the highest point in the slope are very, very stable. In other words, additional driving forces under seismic conditions will have to overcome the -- resistance to sliding of the upper and lower stable masses on either side of the critical mass, before any movement is likely In brief, proper benching along the critical bedding plane is adequate to assure that sliding will not occur. However, con- tinuous inspection should be required during grading in order to assure that the proposed fill is properly bonded or keyed to the underlying bedrock. Item 8 After comlpetion of above, incorporate consultants recommenda- tions and have the soils engineer and geologist approve the plan. The consultant should only sign the plan if recommenda- S. E. Medall & Associates, Inc. Weathertield Homes Page 12 December 13, 2976 W.O. 605 tions are shown on the plan or added as notes (requirecl before the geology section can approve the plans)." All modifications in the grading plans arising as a result of this review have been transmitted to the design engienefr, VTN. All changes are currently on the plans. Item 9 All other consultants reports must be specifically app..-roved by the consulting soils engiener and geologist, or pres:,ent their conclusions and recommendations with supporting data." All previous reports prepared by H.V. Lawmaster and Com1pany with engineering geology by John D. Merrill including all ad<dendums, and the report prepared by Lockwood Singh and P_ssociate.s each listed in the appendix of our previous report, have beem reviewed and we are in concurrence with their recommendations exccept for their recommendations for slope stability and subdr<ain require- ments. Recommendations for slope stability, buttressineg and sub - drains have been presented in this addendum and our previous reports. Our supporting data for our conclusions and recommenda- tions have also been presented in this report and our previous reports. S. E. Niedall & Associates, Inc. Weatherfield Homes December 13, 1976 Page 13 W.O. 605 SOIL ENGINEERING REVIEW SHEET Item 1 The comments in our previous review sheet are still valid and should be satisfied in more detail in accordance with conversations with the consultant." Reply to requirements of October 13, 1976 meeting. Item 1. Although not explicitly stated in our original reply the plans show that the extreme limits of Diamond Bar landslide in the longitudinal direction is essentially alongside the proposed tract boundary. That portion of the landslide that seems to encroach upon the property where grading is proposed is only about 270 feet long adjacent to the entrance portion of Diamond Bar Ridge Road. It should be noted that that proposed grading in this area is along the direction of the landslide. Any proposed removals and replacement with compacted fill along the direc- tion of movement should tend to stabilize rather than mobilize sliding which may only happen for cuts transverse to.the impending motion. in other words, the proposed grading will not in any way affect the landslide. S. E. Medall & Associates, Inc. Weatherfield Homes Page 14 December 13, 1976 W. O. 605 Item 2. Since the required grading for the streets and structures involves the removal of less compe- tent slide materials with properly compacted fall, it is unlikely that they will be affected since any sliding should occur along less competent mate- rials. Reply to Items 1,2 and 3 of Soil Engineering Review Sheet of 10-21-76. Item 1. This item has been satisfied in our original reply. Item 2. This comment is accordingly voided in view of the acceptance of the Frankian solution in so far as the failure mechanism is concerned. Item 3. All errors in typing and other pertinent corrections are reflected in our original reply. The results of our analysis based on the Frankian failure mechanism is hereby attached for you to consider. Sections A -A', B-B' and N--N' were reanalyzed. Based on the L.A. County criteria for buttress design and slope stability analysis, a factor of safety for seismic of 1.1 is considered adequate. Furthermore, use of peak strength in the analysis S. E. Medals & Associates, Inc. Weatherfield Homes Page 15 Item 2 December 13, 1976 W. 0. 605 is also accepted. Contrary to This criteria, we have used 1.25 as our minimum seismic factor of safety and also used yield strengths in our previous analysis. These conditions suggest that slight errors in arriving at the true failure mechanism will be compensated. As may be noted from the attach- ed calculations based on the Framkian solution, higher factors of safety were obtained. in other words, our original designs although based on an approximate failure mechanism are found to be adequate considering the above conditions. An exception to Item 1 is that the R.T. Frank ian slope failure configuration has been accepted by the County. Before we can approve the calculations, we need detailed analyses of the failure slope plane through the buttress fill_" Refer.to enclosed calculations for detailed analyses of the failure slope plane through the buttress fill. We hope that the foregoing discussions have served to clarify and satisfy your requirements. S. E. Medall & Associates, Inc. Weatherfield Homes December 13, 1976 Page 16 W. O. 605 Respectfully submitted, S. E. MEDALL & ASSOCIATES, INC. ARTEDI B. 4ORTEZ MEDALL R.C.E. 26009 JHD:DRE:ABC:SEM:dk Enclosures: Geologic Map, (Fin 4RevisedGeologicC1 Stability Analyses Geologic Legend Correlation of old a _ars c: (2) Addressee 2) Los Angeles County, Attention: i-Ir. Suddeth Mr. Popplar (hand -delivered) 2) VTN, Attention: Mr. Jack Staley S. E. Medall & Associates, Inc. Z W W.O. 605 I W U Pq C3 LO 10 Ld 0- 0 LLI2 u n rn Lr f CO ON p i Ljj z) U L) m Ln z C, W cr d Uw C)N D 0 CC) d W S a OD 0 ul fr C' to O N O0UL0cn U W - U O v 0 0 J LL m co o Qi li UCL a- n Ln rn N o O C) U D(n O r I k a f C C) O Ln C N J O L o 0 D U tfj U' Oti b0 Ln O Q LL O O 00 r- Ln lD N U3 Ld r l roJrIcv cn 0 C3 T LO n rn rTA l d+` C) C;) C: LLuLLJI C Ld c CY) 0 I Ln-) '0 Er r-! 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NCLLI Ln Ln r I Ol N J li M r-j lD n N M Ln N m rn I:{j N Ln r i M r-i c p LL U - CO Gl 011 m cn r lD v c!< Lfl mot^ al M r-i N N l0 M fir M lD 0 C) LD M lt p t;r r-i H U rn m 00 n lD o0 m m rn rn rn OQ N d M co r- N O Ln L!1 Ln lfl r-I N N lD O lO co n M M Ln LO Q z© c0 r I n N n C) Q I r-I r- I N N r-I p W J o 0 0 0 0 0 LD Ln x Q M l0 r-A I l0 r-I r-i r i r-I U d LSD N M oo Ln L M O M O M r- Ln o m r-1 N N M LL U CO lD r-i LC1 Q O C' 1 M M c0 i- 00 U7 r- cV cM r- I H H w O r I N r-I LD H n rI I I H N LS1 OD CD w W. 0. 605 O U ItLnN C n I r-i Ul D 0 U Ln r y L) r sn e ul Ln co GO II Lu n LH M u to Imo. lD . y LO fr IAI t--- :7-- co O r-! O N ri M p a-- IY 11 Z:7 M CT lD L{1 G' n r-I it: co Q O ia 0 W L) r-i N 0 LL VRF-A. CE it -4111-; IYOTrz-' N1:-G-1EC77--,D L FGFND Af ARTIFICIAL FILL a/ QUA TERNAR) AL LUVIUM c I QUATERNARY LANDSLIDE" DEBRIS PUENTE FORMATION CONrACT PLUNGING ANTICLINE y ATTITUDE OF BEDDING 45 QrrrrU®E OF FAULT PLANE TEST PIT- TEST PlT- r.. MEDAL LOC OOD- SINGH BORING - MEDALL BORING LOCnYOOD -- SI GH BORING - L. AWMASTER 0 BORING --- IIIERRIAM A A CROSS SECTION s S PROPOSED SllBDRAIN BORING LOG Project Weatherfield Boring No. 5 Location Diamond Bar W.Q- 605 grill Date 12/8/76 Surface Elev. Logged by Driving Weight ir a 3 w w a 0 o za Q J UNiT (soil, fill, alluvium, siltstone, etc.) No MATERIAL DESCRIPTION (%sand, silt, cloy; cctor, y W CCARE ATTITUDE MEASUREMENTS: consoiidatia»,atc.) a 3 B- BAG B-Bedding F-Fault o za J - Joint RS-Rupture Surface ; a C- Contart Slide Debris: Sandstone, light brown, med- grained, hard. Contact with shale. S: N25W 401E gan st ne an a e n er e s. mo erat,- har ,. amp, wel edAe. B: N45W 40NT Shales are higghlyy fractured 'contain- ` ockets-of.caliche and shattered s coSandstoneandshaleinterbedsasL 2" layer of highly sheared shales witx. E J 1/2" thick seam'of clay and caliche in " contact with sandstone, the contact is highly polished and slick. Contact: N60W 28NE J:'N'10W 77NE Bedding surfaces within the shale are polished and slick. B: N 62W 31NE Fractured zone containing highly sheared shales and sandstone fragments. Heavy limonite staining. At the base of this zone is a 2" clay seam, medium gray, moist, stiff, traces of caliche and pockets of medium brown clay gouge. Shales and sandstone becoming well bedded and hard. L z n" Y o 40w z F- z S 10 1H Sheet of PLATE BORING LOG Project Weatherf ield Boring No. 5 Location Diamond Bar Surface Elev. Logged 5y MB W.0 605 Drill Date 12/8/76 Driving Weight f 3 S w Q 15 o a. 0 UNIT (soil, fill, alluvium, siltstone, etc.) MATERIAL DESCRIPTION (%sand, silt, clay; cator, consolidation, etc.) ATTITUDE MEASUREMENTS: B-bedding F-Fault J- Joint RS-Rupture Surface C- Contort N6 aN o CD c~ng L LjzM a m C-CARE 8_C LU 4 a o o E-z W Mo V Shales & sandstone interbeds. B: N30W 3ONE Fracture zone. Sandstones and shales are highly fractured and heavily stained with limonite matrix of sandy clay is- moist, and soft. Numerous fractures and shears with polished surfaces. S: N52W Vertical S: N30W 64W - 20 Slide Plane: -2" clayey gouge, medium gray brown, moist, shears above terminate into this zone. SP: N2O 25W 31 35tiE BEDROCK: Sandstone and shale-interbeds, sandstones are a light brown to light gray damp and hard, bedding is well developed. 18' B:. N60W 24NE 19' B: N57W 27NE Seepage at 23' from east side. 23' grading into unoxidized sandstones which are media gray damp very hard, shales are a very dar- brown, damp and hard. B: N55W 26NE 25 30 T.D.-72 feet .__ ------ Note: No caving Water standing at 28' Sheet of P1 ATF 3 A— 31IGWd3111 1A BORING LOG Project_ Weatherfield Boring No. 6 Location Surface Elev Diamond Bar Logged by MB W.0 605 Orill Date_ 12/8/76 Driving Weight W lal Q 3 Lj w o 0 oJ 0 a V U€ IT (soil, fill, alluvium, slltstone, etc.) MATERIAL DESCRIPTION (%sand si[t c1a colory , consolidation, etc.) ATTITUDE MEASUREMENTS: B-Bedding F-[vault J-Joint RS-Rupture Surface C- Contact j d rU. cq 0- o U) o O Ld j 3Z-j dm CCA E B-BAG r zw ca 0 " Cr o TOPSOIL AND COLLUVIUM: Sandy clay and clayey sands, dark brown, moist, firm to medium dense, minor rootlets and occasions animal burrow. Clayey sand, light to medium brown, moist medium dense. l/SC 5 10 Slide Debris: Sandstones and shales, highly weathered and fractured, abundant caliche damp, firm. 1,/2" shear separating sandstone on the north side and shales on the south side. Shales are highly sheared and dip into the shear. S: N80 85W 40 64N 15 Shale and Sandstone interbeds. B: N10E 15NW J: N38W 80NE J: EW Vertical Rock is moderately weathered and fractured. 18' S: N40E 56SE displaying at least 4" of offset. J: NS63W J: N80W 62N B: N60E 14NW 20 I Sheet of PLATE V --. MUUMA LT , A1116- BORING LOG Project Weatherfield Baring No. 6 Location Diamond Bar W.0 605 Drill Date 12/8/76 Surface Elev. Logged by MB Driving Weight w c 3 o 0 z a UNIT (Soil, fill, alluvium, siltstone, etc.) MATERIAL DESCRIPTION (%sand, silt, cloy; color, consolidation etc.) ATTITUDE MEASUREMENTS: 13-Bedding F-Fault J- Joint RS-- Rupture Surface C- Contort m U' o o to o U n j z_j C-CARE B-BAG F wo a r ao In FD a 20 S: N 20W 80W 1/2" of caliche filling. Roc on northeast side of shear moderately har B: N 50E 10-15 NW Shales on south-- west side of shear highly sheared, beddin indistinct. 25 Shear leaves hole on northwest side of boring. Rock below becoming hard. B: N 60E 15NW Shale and sandstone inte beds. B: N 70E 10NW 1/8" fracture, caliche filled and heavily stained with limonite. S: N 10W Vertical Shale and sandstone moderately weathered, very hard. 30 1/2" clay sears, stiff, moist, contains carbon flakes. Unoxidized sandstone and shale below, ver hard, damp. B: N 54E 13NW B: N 54E 13NW Unoxidized shales and sandstone shales predominant. 35 40 45 50 Sheet of PLATE Project GTPrLf-.h.rfield S. E. Medall & Associates, Inc. BORING LOG Boring No. 6 Location Surface Elev. Diamond Bar Logged by MB W.0 6a5 Drilf Date 12/8/76 Driving Weight a L z a O 50 0 c, x a U UNIT (S it fill, alluvium, SiItStOn2, etc.) MATERIAL DESCRIPTION Msand, silt, clay; color, consolidation, etc,) ATTITUDE 3EASE1+Rc EP T$: B -Bedding F-Foutt J - Joint RS-Rupture Surface C- Contact o sp O cir O 1i10 x a` C-GORE g- SAG z UJ 0 a Q. Q w a z 9)!w— oz o 7. S5 B: N 55E 1ONW Sandstones and shales, very hard; damp, unoxidized. 60 B: N 70E 14NE S: N 80E 67NW Fracture zone. Sandstone and shale bed highlX fractured and jumbled. Slide Plane:2" clay gouger dark gray, moist, very stiff with slicks at base. SP: N 65E 18NW BEDROCK: The bedrock immediately below the slide displays some signs of disturb- ance such as slightly distorted bedding and minor shearing. S: N 28W 86NE 65 Sheer of PLATE Project Weatherftield BORING LOG Boring No. 6 Location Surface Elev.^ Diamond Bar Logged by MB Y`1.o. 605 brill bate 12/8/76 Driving Weight a 3 w LO w o 65 oJ c a UNIT {soil, fill, alluvium, siltstone, etc.) MATERIAL DESCRIPTION (%sana, silt, clay; Color, consolidation, etc.) ATTITUDE MEASUREMENTS: B-88dding F-Fault J - Joint RS-Rupture Surface J o u a o O W use z C•CORE B BAG z o a a a WQ I-.z o MEo S: N 30W 68NE Minor weathering, ; slightly moist. Bedrock becoming undis- turbed and unoxidized, damp and hard. Sandstone is a medium gray, damp, and very hard. Shales are dark brown, damp, and hard to very hard. B• N 74W 20NE B: N 85W 22NE B: N 75W 14NE 70 75 80 85 T.D. 85 Feet Note: No water No caving Sheet of PLATE BOR @ NG LOG Project, Weatherfield Boring No. 7 Location Diamond Bar Surface Kiev. Logged by MB W.0 605 Drill Date 12/9/76 Driving Weight a 3 to u x w 0 O o c, x UNIT (soil, fill, alluviums siltstone, etc.) MATERIAL DESCRIPTION (%sand, silt, clay- color, consolidation etc.) ATTITUDE MEASUREMENTS: S-Bedding F-Fault J-Joint RS-Rupture Surface C- Contact a o Of V) o z-j aC3 C-CORE B- BAG U a o O z V)w o 0 U FILL: Silty sand, and clayey sand, light brown to medium brown, moist, medium dens buried concrete V ditch V thick SM/SC C/CL CL 5 ALLUVIUM: Clayey sand and sandy clay, medium brown, moist, firm. 10 Sandy to silty clay, light to medium brown, moist, firm. ontains fragments of sandstone near base. ontact: N 4dE 18NW15 WEATHERED BEDROCK: Shale, orange to light rown, smail ca carjo s ngdules vey weathered, bedding indistinct rougly. B: N 58E 22NW BEDROCK: Shale, medium brown grading to very dark brown, damp, hard to very hard, bedding well developed. B: N 84W 18NE Becoming very hard. Drilling difficult. O 5 T.D. 27 Feet Note: No water No caving0 Sheet of PLATE ijjS %4Hli ii AM.>'Y L.1 L1if.+J, J1JI.r. Project Weatherfield Boring No. 8 Location Diamond Bar W.0 60S Drill Date 12/11/76 Surface Elev. _ Logged by_MB Driving Weight w a 3 UJ w 0 o 0. C9 UNIT (soil, fill, alluvium, siltstone, etc.) MATERIAL l7ESCFIiF'TIQN (%sand, silt, Clay; color, ATTITUDE MEASUREMENTS: consolidation, etc.) B-Bedding E-Eovlt J - Joint IDS -Rupture Surface C- Contact 1 m a? o in o W LL i 3 z UJC° C-CORE B-BAG z C a p w z o~ a TOPSOIL: Sandy clay, dark broom., moist, stiff, minor rootlets in upper few feet.. Scattered fragments of sandstone. 5 Slide Debris: Sandstone and shale, light brown, damp; -highly fractured and weather ed. Graben feature, or high angle shear off- setting sandstone and shale. S: EW 40N Bedding in the shale on the south side of the boring. B:.N 10W 10NE . Rock adjacent to the shear is highly distuubed. 10 15 20 Fracture zone, shale and sandstone highly disturbed containing numerous shears and polished fractures. Base of zone - N 70W 6NE J: N 18W Verticals J: N 12E Vertical Shzat of PLATE a. rZ. Meclaii Lit Assccia[as, inc. BORING LOG Project Weatberfield Boring No. 8 Location Diamond Bar 'rye 605 Drill Date 12/11/76 Surface Elev. Logged by MB Driving Weight LLI X F- w n 20 o c x U UNIT (soil, fill, alluvium, siltstone, etc.) MATERIAL DESCRIPTION Msand, silt, clay; comr, consolidation, etc.), ATTITUDE MEASUREMENTS: B- Bedding E-Fault J- Joint RS-Rupture Surface C- Contact a U) a W0 a Li_ CCARE BAG Z 4 a w° Z o o Shale weathered along bedding and fracture surfaces. B: N 80W 91NE Fracture zone. B: N 80E 1.0N J: N 20E 75NW J: E-W 77S Shale highly fractured, very moist:, weathered to a stiff clay. Southeast side of boring. Shear: N 45E 58NW, off- setting.sandstone and shale, shear term- inates into slide plane. 25 1 30 Slide Plane: 2-4" clay gouge, dark gray, stiff, moist, with slicks. SP: N 40W LONE BEDROCK: Sandstone, light brown, damp, hard, slightly deformed by drag. Sandstone and shale interbeds, dark gray, damp, hard to.very hard, slightly weathered, becoming unoxidized and very hard at 37'. B: N 65W 6NE J: N 60E Vertical 35 40 Sheet of PLATE PLO) O'-f l iNLOG Project Wearherfield Boring No. 8 Location Surface Elev. Diamond Bar Lodged by MB W. 4 645 Drill Date 12/11/76 Driving Weight w a u- w n o c a c UNIT ( sail, fill, alluvium, siltsfone, etc.) MATERIAL DESCRIPTION (%sand, silt, clay; color, ATTITUDE MEASUREMENTS: consolidation etc.) B- Bedding F-Fault J- Joint RS-Rupture Surface C- Contact M a j o N Q inQ I 3 C- WRE B- BAG F Q a W P z o 40 Sandstone, medium to dark gray, very fine grained,. damp, very hard. B: N 70W 7NE Shale and sandstone interbeds, unoxidized and very hard. 45 50 55 T. D. 55 Feet Note: No water No caving Sheet of PLATE S. IE. Medall & ASSOCIateS, Inc. BORING LOG Project Weatherfield Boring No: 9 Location Surface Elev. Diamond Bar Logged 6y MB W.0 605 Drill Dote 12/11/76 Driving Weight w E d 3 w x E w A D o 0 xa t UNIT (soil, fill, alluvium, siltstone, etc_) MATERIAL DESCRIPTION Msand, silt, cloy; color, consolidation etc.} ATTITUDE MEASUREMENTS: B-Bedding F-Foult J- Joint - RS•- Rupture Surface C- Contact m U] Y' lr' a a a N_o _ W 6 0 N o f C-CORE z z C, u w Uj El -BAG ofz-A >_ 7oa - ` TOPSOIL: Sandy clay, dark brown, moist, rrLinor rootlets in upper few feet. Scatteref fracgrents of sandstone. 5 WEATHERED BEDROCK: Shale. BEDROCK: Shale, medium brown to very dark brown, dare, hard to very hard, bedding well developed. B: N 58W 10NE B: N 70;1 LONE 10 15 20 T.D. 20 Feet. Note: No water No caving Street of PLATE CORRELATION OF OLD & NEW LOT NUMBERS Tract 33197 W. O. 605 Tract 32974 (old) 1 28 2 27 3 26 4 25 5 24 TRACT 32974 New 1-23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Old 1-23 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 S. E. Medall & Associates, Inc. W. O. 605 TRACT 32974 (continued) New Old 51 56 52 57 53 58 54 59 55 60 56 61 57 62 58 63 59 64 60 65 61 66 62 67 63 68 64 69 65 70 66 71 67 72 68 73 69 74*- 70 75 71 76 72 77 73 78 74 79 75 80 76 81 77 82 78 83 79 84 80 85 81 86 82 87 83 88 84 89 85 90 86 91 87 92 88 93 89 94 90 95 S. E. Illledell & Associates, Inc. W. O. 605 TRACT 32974 (continued) New Old 91 96 92 97 93 98 94 99 95 100 96 101 97 102 98 103 99 104 100 105 101 106 102 107 103 108 104 109 105 110 106 111 107 112 108 113 109 114 110 115 111 116 112 117 113 118 114 119 115 120 116 121 117 122 118 123 119 124 120 125 121 126 122 127 123 128 124 129 125 130 126 131 127 132 128 133 129 134 130 135 S. E. Medall & Associates, Inc. W. 0. 605 TRACT 32974 (continued) New Old 131 136 132 137 133 138 134 139 135 140 136 141 137 142 138 143 139 144 140 14:5 141 14.6 142 147 143 14 8 144 149 145 1S0 146 151 147 15.2 148 153 149 154 150 155 151 15.6 152 157 153 15 B 154 1519 155 16?0 156 161 157 162 158 163 159 16-4 160 165 161 166 162 16 :1 S. E. Medan & Associates, Inc. s• s s• 700 sss ss 700 EXISTING GROUND 1100 to w J Uj > N 0_ — J o a o CO -- s ` o -2° 1000 Tpss f m ti Tpsh _ — 72 , 900 — PROPOSED GRADE T ^ TD - f ` 45' ?-~-.--`_-y` 1 _-? _ O - is0-_ 0 -0 - — — Tpsh 35 Col 800 TD Tpss -- r 700 Tpsh -- SECTION I - y M ti Q EXISTING GROUND a Cn o PROPOSED GRADE OD Tps yam Tpsh ? TD, SECTION 2-2' Q w W J J 0 m 00- 50 - ?- 7`5"r 1 72` TD 83, 1 1 --- /i Tpss 7? T/'E OZOG/G <I/Y OYE.QALL /CTUR OF T./E S'/TE" Aif/Q /YI.9Y 4107- 47Z,1L LOC.9G Y.4F/fIT/JJ/1/S' (/CEO /r!/ LO E ,'Tf Es/L/Ty Ai1/ALYS'ES' Q w v 0 Cr CL R t1 0 Tpss PLATE Ila sl 700 REVISED 3-6-78 S. E. Medall & Associates, Inc, Consultants in the Earth Sciences 1030 50. Bundy o-., Lis Argmm. Ca. 9Ut1G6, (213) 3904079 2168 So. Hathewdy SS.. 5—ta Ara, Ca. 92705, 17W 546-6602