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Home My WebLink AboutCT 83-01; Monarch Villas Lots 2-7; Soils Report; 1987-10-06LEIGHTON and ASSOCIATES ,~ - - - - - .- - - - - _. - *SOIL ENGINEERING *GEOLOGY *GEOPHYSICS *GROUND WATER aMATERIALS TESTING wAZARDDUS WASTE ASSESSMENT October 6, 1987 Project No. 8840360-04 TO: ATTENTION: SUBJECT: S & S Construction Company of San Oiego 5845 Friars Road, Suite 1106 San Oiego, California 92108 Mr. Jack Tilney Interim As-Graded Report of Rough Grading Operations for Building Pad Areas, Lots 2 Through 7, Proposed Condominium Complexes, Monarch Villas, Carlsbad Tract 83-1, Carlsbad, California Introduction In accordance with your request and authorization, provided herein is our interim as-graded report of rough grading operations for the subject condominium building pads. This report summarizes our observations, field and laboratory tests, and geotechnical conditions encountered during grading performed between September 24 and October 5, 1987. The subject site is located at the northeast corner of El Camino Real and Levante Street in Carlsbad, California (Figure 1). Accompanying Maps, Illustrations, and Appendices Figure 1 - Site Location Map - Page 2 Table 1 - Summary of Building Pad Expansion Potential - Rear of Text Table 2 - Foundation Design Considerations for Expansive Soils Underlying One- and Two-Story Residential Buildings - Rear of Text Plates 1 and 2 - Density Test Location Maps - In Pocket Appendix A - References Appendix B - Summary of Field Density Tests. Appendix C - Laboratory Test Results Appendix D - General Earthwork and Grading Specifications Appendix E - Slope Maintenance Guidelines for Homeowners 5423 AVENIDA ENCINAS, SUITE C. CARLSBAD. CALIFORNIA 92008 (619) 931.9953 - - _. BASE MAP: USQS ENCINITAS. CALIFORNIA QUADRANGLE - - 0 2000 4000 Ret I SITE LOCATION MAP S IL S / MONARCH CARLSBAD, CALIFORNIA I - - - .~ - - - .- - - - - 8840360-04 It is our understanding that this interim as-graded report is intended to satisfy a requirement of the City of Carlsbad to obtain building permits. The informa- tion presented in this report will be incorporated into the more comprehensive, final as-graded report for the Monarch Villas subdivision to be prepared shortly after completion of rough grading for the entire site. This interim report summarizes our observations, test results, the geotechnical conditions of the building pad areas. and provides recommendations for design and construction of the proposed buildings. The grading plan (20-scale) prepared by APEC. Inc., dated March 16, 1984, was used as a base map to present approximate locations of field density tests (Plates 1 and 2). Rough grading operations of the building pad area for Building Pads 2 through 7 were performed during the period of September 24 through October 5, 1987. Grading operations will be performed in the near future for the remainder of the subject site. As-graded geotechnical conditions and field density test locations of the entire site will be presented in the final as- graded report. Summary of Grading Operations Grading of the subject site is being performed by Reed-Thomas Company, Inc. Grading largely consisted of removal of the existing paved street, excavation of lower building pad areas, and minor cuts and fills of the pre-existing graded area. Specific operations during interim rough grading included: l Brushing and removal of surface vegetation (with the exception of slope vegetation) and debris prior to grading of the site. a Removal of the existing asphalt concrete paved street, and buried utilities. In one area, a storm drain was left functioning in place. Once this storm drain has been retired by the construction of a new storm drain, it should be backfilled with lean concrete (Plate 2). Geotechnical Engineering Summary l Site Preparation and Removals Prior to grading, the building pad areas on the subject site were stripped of surface vegetation and debris. The existing street asphaltic concrete pavement and aggregate base were ground in-place and processed with site soils to make an aggregate fill mix. Existing portland cement concrete curb, gutter, and sidewalk were removed from the site. Buried utilities, including storm drain, water main, and sewer main lines were removed from the site. One section of storm drain was left functioning in place. A new storm drain alignment is planned to replace this storm drain. Once the new storm drain is installed, the old storm drain should be backfilled with lean concrete (Plate 2). -3- l!lLl hl LEIGHTON and AS3,ClATES lNCORPORATED - - - - - - ,- - - - - - 8840360-04 Fill Placement After processing the excavated areas, native fill soils and A.C. soil ag- gregate fill mix were spread in 6- to 8-inch loose lifts, moisture conditioned as needed to obtain near-optimum moisture content, and compacted to a minimum relative compaction of 90 percent of the maximum dry density (ASTM Test Method D1557-78). Areas of fill in which field density tests were less than 90 percent relative compaction were reworked, recompacted, and retested until the fill reached 90 percent relative compaction and adequate moisture content. In areas where fill placement was observed as being nonuniform, these areas were reworked until uniformity in soil mixture and adequate moisture was achieved. Field and Laboratory Testing Field density tests were performed by the sand cone, nuclear gauge, and drive cylinder methods in general accordance with ASTM Test Methods D1566-82, D2922-78, and D2937-71, respectively. The approximate locations of the field density tests are shown on Plates 1 and 2. The results of the field density tests are presented in Appendix B. Laboratory maximum dry density tests were performed in general accordance with ASTM Test Method D1557-78. The results are presented in Appendix C. It should be noted that the accuracy of test results is dependent on the preci- sion of the laboratory and field testing procedures as outlined by the American Society for Testing and Materials (ASTM). Representative samples were collected from near-surface soils of finish graded pads. Laboratory tests for expansion index were performed on these samples in accordance with UBC 29-2. The results of expansion tests are presented in Appendix C. Graded Slopes Fill slopes in the "crawl space" areas between the interior and exterior footings were constructed in accordance with our recommendations contained in our geotechnical investigation report (Appendix A. Reference 3). The slopes between the upper and lower footings were located by projecting a 2:l (horizontal to vertical) slope upward from the lower pad grade to the upper pad. Fill slope faces were compacted by sheepsfoot rollers and then track- wal ked. Grading for the major slopes outside the building pad areas has not been completed at this time. As-graded geotechnical conditions of these slopes will be addressed in the final as-graded report. Retaining Walls Retaining walls are proposed west of the building pads at Lots 3. 4, and 6 (Plates 1 and 2). As of this date, work has not begun on the construction of these retaining walls. Retaining wall footing excavations and backfill should be observed by a representative of this firm and will be addressed in the final as-graded report. - 4 - - - - - - .- - - - - - - - 884036D-04 l Expansive Potential Expansion index tests were performed in accordance with UBC 29-2 on repre- sentative samples of the near-surface soils of the subject lots. Based on these test results and visual evaluation, the expansion index of these soils ranged from very low to low. Results of the expansion index tests are presented in Appendix C. Foundation and slab recommendations for building pads with medium and high expansive potential soils within 3 feet of pad grade are discussed in our previous report (Appendix A, Reference 3). Conclusions Geotechnical aspects of the building pad area of the subject site have been evaluated and treated during grading in accordance with the recommendations presented in our geotechnical investigation report (Appendix A, Reference 3), field recommendations during the course of grading, and requirements of the City of Carlsbad. It is our opinion that the building pad areas of Lots 2 through 7 are suitable for their intended use provided the recommendations of this report and our previous report are incorporated into the design and construction. The following is a summary of our conclusions: o The geotechnical properties of the onsite soils encountered during site grading were generally as anticipated. e Site preparation and removal of utilities and pavements were observed and/or tested prior to fill placement. e Very low to low expansive soils at finish grade exist on the subject building pads. e Fill soils were derived from onsite soils and A.C. soil aggregate fill mix. Fill soils in the pad areas of Lots 2 through 7 were placed and compacted to at least 90 percent relative compaction in accordance with the General Earthwork and Grading Specifications (Appendix A, Reference 3) and the requirements of the City of Carlsbad. Recommendations l Foundation and Slab Design Considerations Construction of foundations and slabs should be performed in accordance with the recommendations of our previous report (Appendix A, Reference 3). Laboratory test results indicate expansion potential should be very low to low (Table 1). Treatment of.the foundation, slab and flatwork design for very low to low expansive soil designations should be based on Table 2. It should be noted that Table 2 of this report supersedes the Table 2 of our previous report (Appendix A, Reference 3). In order to help mitigate the potential for misalignment of the proposed garage door openings(s), we recommend a grade beam be provided across the garage door opening(s). This grade beam should be designed in accordance with -5- - - - - - - ,- - - -. 8840360-04 The potential for slab cracking may be reduced by careful control of water/cement ratios. The contractor should take appropriate curing precau- tions during the pouring of concrete in hot weather to minimize cracking of slabs. We recommend that a slipsheet (or equivalent) be utilized if grouted tile, marble tile, or other crack-sensitive floor covering is planned directly on concrete slabs. All slabs should be designed in accordance with structural considerations. l Surface Drainage and Lot Maintenance Positive drainage of surface water away from the structure is very important. No water should be allowed to pond adjacent to the building. Positive drainage may be accomplished by providing drainage away from the building at a gradient of at least 2 percent for a distance of at least 5 feet away from the building, and further maintained by a swale or drainage path at a gradient of at least 1 percent. Where necessary, drainage paths may be shortened by use of area drains and collector pipes. We suggest the installation of eave gutters and downspouts on the buildings, which will facilitate roof runoff away from the foundation. The discharge water from the downspouts should be directed away from the buildings to an appropriate noncorrosive outlet. Drainage away from the slopes should be maintained at all times such that water does not drain over the top of the slopes. The need for and design of drainage devices on the site is within the purview of the design civil engineer. Planters with open bottoms adjacent to the building should be avoided, if possible. Planting areas at grade should be provided with adequate positive drainage directed away from the building. Planters should not be designed below grade unless provisions for drainage such as catch basins and pipe drains are made. Upon sale of housing units, maintenance of lots by the homeowner and/or by the Homeowners Association is recommended. Our Slope Maintenance Guidelines for Homeowners is therefore included in Appendix E for your review and distribu- tion to the future homeowners and/or Homeowners Association. l Subdrains Construction of a "crawl space" subdrain should be performed in accordance with the recommendations of our previous report (Appendix A, Reference 3). The stability fill subdrain and outlets constructed during rough grading are identified on the As-graded Geotechnical Maps. Where outlets are not tied into the storm drains, they should be cleared of soil cover or other potential blockage which may have occurred since initial subdrain construction. Drainage design from outlets that are not tied into storm drains should be provided by the project civil engineer. It is recommended that the Homeowners Association further maintain these outlets, as well as retaining wall drainage outlets, to prevent future blockage for those drains in common areas. Individual homeowners should maintain outlets on their respective properties. The developer should provide this information to the homeowners. -6- LEIGHTON end ASSOCIATES !NCORPORATED - 8840360-04 Should a subdrain be intercepted or damaged in the future, even if it is dry, we recommend that the subdrain be repaired. If a subdrain requires reloca- tion, the subdrain may be rerouted provided a minimum gradient of 1 percent is provided in the direction of the outlet. If you have any questions regarding our report, please do not hesitate to contact this office. We appreciate this opportunity to be of service. Respectfully submitted, - LEIGHTON AND ASSOCIATES, INC. - EO/SRH/RW/lk - Distribution: (3) Addressee Ro&&%$? Chief EngineeriAg Geologist -7- LEIGHTON and ASSOCIATES lNCORPORATED - - - - - .- - ,- - - 8840360-04 - Lot - 2 3 4 5 6 7 TABLE 1 Summary of Build.ing Pad Expansion Potential Expansion Potential Very Low Very Low Very Low Low Low Low Expansion Index of Representative Test 3 3 3 24 24 24 LElGHTON and ASSOCIATES INCORPDRATED ___~~,. .~.-.- .-.-_ ._^~“_^_.“.. 8840360-04 TABLE 2 - - FOUNOATION OESIGN CONSIOERATIONS FOR EXPANSIVE SOILS UNDERLYING ONE- AND TWO-STORY RESIOENTIAL BUILDINGS - - - - - IID*nslOn Ind*s 0 - 20 YEPI Lhl EIPAWs,O"* Lay ElPAllSlOl * "EO,"" ElPU1510** ",C" tvP*"s,o"* OlU-StW, FOOll"9% All IWIInqS I2 Inch.1 "11 ,.wtinp, 12 lnchcr E~twlor looclnpr II frh,far twtingr 24 ik* loll I) dwa. rooth?qr cmt,n- ""US. onr "0. , ,,bbr d..P. roollnqr contin- "WI. on, "0. , reblr Inches eep. In,.rlor ,ndl*, WD. Intwtor top ‘"d bottm. top rnb bottom. footln9l 12 ,ncncr deep. One MO. ‘ ,.b4l top rnd fwhg, I8 lncha a.eP* one "0. I .-ear top ."d both.. boltca. lW4kWY A11 fooottnq, II ,"Ch., cmtlnqs A11 ,o.atlnp, ,I ,"chcr iI** ".a* I, d*eD. fWtW,l conth- footlnp‘ c.nttn- A11 footlnp, ,I Inch.1 E.rercor ‘oothq, I4 dClP. "0"s. on* "0. , *lb, deep, "O",. on. "0. , **ha, fwt,ngs ConfIn- ,nctlcr dleJ. 1ntrrtor "0"s. on* no. , ,,bl, top rnd bptto.. top rnd botton. footlnqs II I"<rm, deep. top and bcxto.. fw~. I rehw ta@ ("0 Lirlnp Area 4 inch*, LhlCk. Id- 4 inches ul,ct. 6x6- 4 Inches th,ck. 6x6- 4 Inches CllCk. ,4 floor Slab 10110 reIded wire rrh. lo/lo welded wire mall. 6/6 ",1&d *,rr man. reb., I II' on cmle* (see "Oh 2) I-lath sm* ,ryw over .P,"Ch s*n* hyer 01.r "l,h ,4 dPClS , ,I' 0.4 6 -11 vtspreen ml,,",* 2-inch rrnd l.ycr ore, 6 .,I vlsq"ecn smIst"rs 6 .,I Vlrquccn mot,t"re cmtw .ith I-1"ch l."d ~t'l;;,.wr Z-Inch brrrlrr (1~1 Z-Inch barrkr we, I-,"Cb layer 011, 6 .I, vlsq"~~" srnd bar.. sand bare. m,,turr barrit* 0.w I-inch stod base. k&g. floor 4 ‘"CrwS Ch,Ck. ‘d- 4 ,"Ch~, m,.d. ‘s‘- 4 Inches Lhkk. &I- 4 ,ncn*s thkk. loll0 reldrd rlr* meIll loll0 "lldd l,,. rm 616 welded rlr. r,h I4 *St..*, I*' 0" I%,$ i:rb;dy slab. 24ncD ~9"~::: slab. Z-,ncb or qurrtrr slab. center tad q".rter slab. I-‘"Cl! Sl"d b‘s*. 4-sna ‘410 base. Presoakf"g SolI, alstcned to nar Sark upp(, 12 Inches OY urirq Soak UPPI, LII inchrs to SO,, "OW, t4 f"ChCS opthum mi,tur, content to IL IC,Sl 1.2 I to It \e,,t 1.4 A wthm A**1 ."d 6Waqc Slab ~,:c;;h,. depth of optb". mtsturc *t ,*rst 1.3 I opthim rr,,ture CO"te"t oc misture ContenL or content or 4 percent SOilS rbilr. opthun mist"r* 5 perctnt abare oprh". 5 pcrrmt .bo"l opt1m. mlsture contml. rhld- mlrt",~ cmtmt. rhlch- (se* note 41 content. rhichcrer is tre, IS prcrter. WC, is orrater. gnat4r. l Erpmrton Itld,, drlrr.lnrd ,n rccord~ncc r,tll test "ethod WC 29-z. NOTES: 1. "lni.". ,.,,,t,ng "l&h should be 12 Inchel for on.-sto,, b"lld,ngl. 15 Incbel for t"O-story kulldlnp,. mei t4 fnch*r ,or lrolrred spread fOOLi"OS. 2. Urr msh and reb,, ,hwtd be ,,,,ced ,t .MlOHElGHt of slab. I I. ,,o,,t, .~wl,,, Slab tro. wrlrter foOtln9S. S,,b ,l"C"I, ,hWM be a mhltum Of I huh deep. I 4. It lhw,d be noted thrt ~rcrork,"~ "y re.qu,re an rztmde.3 ,x,,od 0, tlr to red ul, recol"ded a,rturt content. 5. h* WW,,O" tndrs over ,,O. ,peChI r,coll"d,tk.", "(11 b. ~'o.,dtd by th. peotemnicr, ~m,u,tmt (,I nrc~rrrr,, Ms.0 01 rcturl 11~14 co"dltlo"t. I 6. A,, depth, arc ,,,rt,re lo 11.0 ,"bgr,dr or fInIshed 0ro""d S"rfaC*. whlchevw 1% lore*. I I 1. th* rb.art nbeacnt and ,*lnforcemnl Con,,*rrrtlo", ,I. .,n,w. &wld*ll"*s IhlCb "y bs ,nc,rr,,* at tll, *o~rcL,on 0, th, ,lr"Ct"rll rnginrrr. I APPENDIX A 8840360-04 APPENDIX A REFERENCES - 1. Associated Professional Engineering Corporation (APEC), 1984. Grading plans for Monarch Villas, Carlsbad Tract No. 83-l. 5 Sheets, Drawing No. 233-4A, Dated March 16. 2. Dale Naegle, AIA, Architecture and Planning, Inc., Plans for Monarch Villas, Prepared for Shape11 Industries, 37 Sheets, Dated April 1984, Revised November 17, 1986. - 3. Leighton and Associates, Inc., 1984, Geotechnical investigation, Monarch Villas, Carlsbad Tract 83-1. Carlsbad, California, Dated June 6. - 4. , Unpublished, in-house data. - AERIAL PHOTOGRAPHS Date 1973 Source San Diego County Scale 1:12,000' 1:12,000’ - 1978 San Diego County Flight 31 - 38 17B - 31 Photo No. 39 and 40 32 and 33 - - - - A-i APPENDIX B - 8840360-04 - APPENOIX B EXPLANATION OF SUMMARY OF FIELD DENSITY TESTS - A. Test No. _: OOl* Field density test by Sand-Cone Method (ASTM 0155642) - 001. Field density test by Drive Cylinder Hethod (ASTH 02937-83) - 0011 Field density test by Nuclear Method (ASTM 02922-81) B. Test of: CF --- Compacted fill - SF --- Slope face - FG --- Finish grade NOTE: - Soil type and descriptions are presented in Appendix C (Summary of Laboratory Test Results). - - - -, B-i j - - -i 1 -j - PROJECT NW : S 6 S CONSTRUCTION I JWRCH VIURS TEST LOCRTION SOIL ELEV OR DRY IIENSLPCF) MOISTURE(~I RELATIVE llEl%lRHS TEST TEST iES1 No DATE OF IN Y/26/87 CF TYPE LOT 4 NW10 ElWiS 4 LOT 4 N&U25 El0285 4 LOT 2 Nl'dffi El@290 4 LOT 3 Nl0lW El8175 4 LOT 4 N10245 El0155 4 LOT 6 NlKW El0048 4 LOT 3 NlBlZB ElUlSS 4 LOT 3 N10115 El@228 4 LOT 4 NM264 El8155 4 LOT 4 Nl0245 El0110 4 LOT 4 N10258 El0098 4 LOT 4 NW65 El0120 4 LOT 2 Nl0110 El’&% 4 LOT 2 NW15 Elm 4 LOT 2 N10235 El6270 4 LOT 2 NW35 El0278 4 LM 2 N18198 El= 4 LM 2 N18140 El8305 7 LM 2 N10115 El0255 7 LOT 2 NkW@El& 5 LM 2 NW15 El0278 5 LM 2 NW40 El0325 4 LM2 Nl’ZS5 El0285 4 XPTH (FEET1 67.8 FIELII !W FIELD OPT CWPKTIffl 24 3/26/07 CF 3Y Y/26/87 ff 411 9/28/07 CF 5u Y/28/87 cF 6u Y/28/07 CF 7u 9i2aia7 cF a* 9i2aia7 cF 9: 9i2aia7 CF lW Yi20lal CF 11s 9i2Yia7 a i2u Yma7 cF 138 ¶/29/07 CF 1411 Yma7 a 1st mia7 cF 164 Y/29/87 CF 171 9/29/87 CF lau 9i30ia7 u 19~ 9ma7 SF 2w Y/38/87 CF 21s Ymia7 a 22s 9ma7 CF 23; Yi30ia7 a 2u Yma7 a 70.0 68.0 73.5 73.0 73.0 74.5 74.0 73.0 76.0 78.0 11.0 67.0 7%.8 69.8 73.0 71.8 76.8 75.0 72.0 71.8 78.0 75.0 LM2 N10260E10325 4 77.5 110.3 117.5 11.5 12.0 185.3 117.5 11.8 12.8 lea.2 117.5 12.1 12.8 112.1 117.5 12.8 12.0 111.6 Iii.5 13.1 12.0 113.9 117.5 12.8 12.0 114.1 lli.5 11.8 12.0 189.2 117.5 11.7 12.8 111.6 117.5 12.5 12.0 107.6 117.5 14.5 12.0 186.1 117.5 11.9 12.8 107.4 117.5 11.8 12.0 lea.1 117.5 13.1 12.8 187.0 117.5 12.1 12.0 113.4 117.5 14.0 12.0 111.5 117.5 13.2 12.8 109.5 117.5 11.7 12.8 186.0 116.5 13.3 13.5 105.2 116.5 13.0 13.5 187.5 113.8 19.3 17.8 ie4.9 ii3.e 16.6 17.0 105.8 117.5 11.7 12.0 112.1 117.5 13.8 12.0 1187 117.5 11.1 12.0 WI 94. 98. 92. 95. 95. 97. 91. 93. 95. 92. 90. 91. 92. 91. 97. 95. 93. 91. ?a. 95. 93. Ye. %. 94. SM!NfY OF FIELS DENSITY TESTS i?wi I PROJECT W4EER : WG0-84 - - -. - - - - - SWX3V ff FIELD DENSITY TESTS PAGE2 PROKCT tUlStR : aa4UU-04 PKWECT t&HE : S 6 S UlNSTkitTION I loylRcH VILL!X TEST TEST TEST TEST LOCRTIffl SOIL ELEV OR DRY DEtiSGtF) KWlJRE(Il RELRTIVE RfPARKS No ME a TYPE 251 Y/38/07 ff CM II)yIRcR NlW5 Elm 4 26* lW?N07 CF LOT 4 N10378 El0110 4 274 l’Ull07 F6 LOT 3 NW25 El'&%5 4 281 ieielia7 ~6 LOT 3 N1&?10 El0095 4 29l 1eiwa7 F6 LOT 2 Nle140 El0365 4 3ei ieielia7 F6 LM 2 NW55 El@315 4 318 10101/07 CF CJ KU&W NM475 El0195 1 CmH (FEET1 70.8 75.0 75.6 75.6 79.5 79.5 63.0 33 1eielia7 ff 351 iwalia7 a 34t wwa7 ff 354 10ifwa7 a JM~ wcwa7 CF 37~ leieiia7 a 381 welia7 CF 3w leielia7 a 4m 10/01167 CF 41: leiwa7 SF 424 lwa2ia7 a 43 ltaiwa7 a 44# 18/@2/87 a 451 leie2ia7 a 464 imia7 ix 478 iwwa7 CF 40~ ram07 SF LOT 5 N10530 El@318 4 71.8 LOT 1 N10765 El8228 4 76.0 LOT 5 NM490 El0265 1 66.8 LM 5 NlE46e El0315 4 73.5 LOT 5 NW15 El8265 4 75.0 LOTS NM475 E1924e 1 69.0 LOT a N1&25 ElOlle 1 62.8 LM4 N1@370 Elelbe 1 77.0 LM 5 NIBJIB El@350 7 76.8 LOT2 N10210 ElBJ35 1 73.0 LOT 5 NW70 El&W0 4 73.0 LM7 N10Z65 El0330 7 75.5 LM a HI0623 El0125 4 65.0 LOT6 NlW5 El0110 4 73.5 LOT 7 NiU5 El@315 1 77.5 LOT6 NW% El8870 5 70.8 LM3 NlelZB El8158 1 72.0 FIELD lylX FIELD OPT CWWTIaY 106.0 117.5 13.2 12.8 109.0 117.5 13.5 12.0 lea.7 117.5 11.2 12.0 lea.9 117.5 11.1 12.0 110.6 117.5 11.4 12.0 110.2 117.5 11.7 12.0 111.3 119.5 1i.e 10.5 189.7 117.5 11.0 12.0 110.2 117.5 12.2 12.0 109.9 119.5 11.4 10.5 109.9 117.5 11.7 128 lie.2 117.5 11.2 12.8 189.2 119.5 11.4 10.5 lE&l 119.5 11.1 10.5 112.9 119.5 13.5 le.5 108.2 116.5 14.5 13.5 110.7 119.5 18.0 18.5 109.3 117.5 12.7 12.0 lea.9 116.5 16.5 13.5 107.0 117.5 12.0 12.0 189.9 117.5 12.3 12.0 112.3 119.5 14.3 10.5 104.7 113.8 16.0 17.8 110.9 119.5 11.1 IL5 CL) 91. 93. 93. 93. 94. 94. 93. 93. 94. R 94. 94. 91. 98. 94. 93. 93. 93. 93. 92. 94. 94. 93. 93. - - SWIRRY ff FIELD KNSITY TESTS Pa3 PROJECTWi8ER:- PROJECT t&HE : S L 5 CoNsTiWTIffl / llwRFiUi VILLRS TEST LOCATION SOIL ELEV OR TEST TEST TEST ta cm OF 491 10/02/87 a 508 10/02/87 CF 51~ wwa7 ff 521 10/03/87 SF S?,: lBi03/07 FG 541 18103187 F6 551 i0103/07 a 564 10/03t07 CF 571 10/03/87 F6 581 10/03/87 F6 5% 10/03/07 SF 681 10/03187 CF 614 10103i07 F6 621 10103l2.7 SF 63 10105H.7 F6 648 10105)5/87 CF 65~ 10ma7 a 661 10/05/87 CF 67# 10105/07 a w 10/85/87 a 6% 10/05/87 F6 781 101W87 F6 711 10/05/87 SF 72- 10ma7 a DRY DEtiWCR Iw)ISTUREW RELRTIVE REWIIKS FIELD WIX FIELD OPT MIPRCTION -- - - LOT 0 LM 7 LOT 7 LOT 4 LOT 4 LOT 4 LOT6 LM 5 LOT 6 LOT 6 LM 6 LOT 7 LOT5 LM 5 LM 5 LM 7 LM 1 LM 0 LM 7 LOT 8 LOT 7 LM 7 LM 7 LOT B WE DEPTH (FEET) N10625 El@85 7 68.0 NlW5 El0265 7 73.5 Nl’&B El0195 5 75.5 NW65 El0115 4 76.0 NIB285 El0120 4 73.5 Nl036~0 El0095 4 79.0 N10405 El0185 4 79.0 Nl03B El8275 4 78.0 N10395 El0135 4 79.9 Nl043# El0075 4 74.5 NlD410 El0145 4 77.5 NW90 El@238 1 77.0 N10475 El0360 7 88.0 NlW El0270 7 77.5 NW75 El0360 4 74.7 N18688 El@90 5 79.0 NW’05 El0205 7 76.0 N105B El0130 2 74.5 NW90 El023 7 70.0 HI8565 El0010 7 Z0 N1’2675 El0295 1 80.0 Nls615 El0185 1 74. .9 N1057.5 El0300 1 77.S Ml8638 El0115 1 77.0 104.9 116.5 12.2 13.5 104.8 116.5 13.7 13.5 LB?.0 113.0 17.4 17.0 109.2 117.5 11.9 12.0 114.0 117.5 11.9 12.0 114.4 117.5 12.1 12.0 114.2 117.5 11.5 12.0 112.3 117.5 11.8 12.0 113.9 117.5 11.6 12.0 113.8 117.5 13.3 12.0 110.8 117.5 11.1 12.0 111.1 119.5 11.2 10.5 109.4 116.5 11.9 13.5 109.7 116.5 12.1 13.5 110.8 117.5 10.9 12.0 188.5 113.0 17.0 17.0 188.7 116.5 15.7 13.5 112.4 119.5 11.9 11.5 107.3 116.5 14.3 13.5 105.9 116.5 12.7 13.5 110.7 119.5 11.7 10.5 111.7 119.5 10.8 10.5 111.0 119.5 10.9 le.5 110.5 119.5 12.4 10.5 (iI 9a 90. 98. 93. 97. 97. 97. 96. 97. 97. 94. 93. 94. 94. 94. 96. 93. 94. 92. 91. 93. 93. 93. %. - - - - ,- SUlQlARY OF FIELD DEHTY TESTS pRGE4 PAaTECTt4WBZR:@#3#%4 PROJECT =:S 6 SCUKTRLKTION / WEylRUiVILLRS TEST TEST TEST No Dm OF 73~ 10ma7 CF 74^ !0/05/87 SF 7% imi/a7 FG 7M1 W05f2.7 FG 77^ 10/05/87 SF 781 10/06/87 FG TEST LOCRTIffl SOIL ELEV OR DRY DENSWF) K!ISTUREWI RELllTIVE REmtim TYPE DEPTH FIELD WIX FIELD OPT capRcT1L-N (FEET) LOT 8 NlR&05 El8885 7 78.0 107.8 116.5 13.3 13.5 LOT 4 NW90 El0045 4 66.0 166.6 117.5 11.7 12.0 LOT b N10645 El0010 4 73.7 109.7 117.5 12.3 12.8 LOT 8 NlW8 El0075 4 79.0 108.1 117.5 12.8 12.0 LM 8 NlR565 E9975 7 76.5 107.4 116.5 14.2 13.5 LOT 3 N10165 El0130 1 70.3 114.3 119.5 8.7 10.5 Ii) 93. 91. 93. 92. 92. 96. - - - - APPENDIX C - - - - - - - - - - - ,- - .- - - .- MAXIMUM DENSITY TEST RESULTS 1 MAXIMUM OPTIMUM SAMPLE SOIL DESCRIPTION DRY DENSITY MOISTURE (PCF) CONTENT W 1 Light brown, silty sand (Fill) 119.5 10.5 2 Gray-brown, clayey sand (Topsoil) 119.5 11.5 3 Gray-brown, slightly silty, fine sand 119.0 12.0 4 Light brown, fine sand 117.5 12.0 5 Green, silty clay 113.0 17.0 6 Processed A.C. with sand 125.0 10.0 7 Light to medium brown, silty sand 116.5 13.5 a Green, sandy clay 116.5 16.5 S & S CONSTRUCTION/MONARCH VILLAS APPENDIX D - 8840360-04 GENERAL EARTHWORK AND GRADING SPECIFICATIONS - - - - - - -- - 1.0 General Intent These specifications are presented as general procedures and recommendations for grading and earthwork to be utilized in conjunction with the approved grading plans. These general earthwork and grading specifications are a part of the recommendations contained in the geotechnical report and shall be superseded by the recommendations in the geotechnical report in the case of conflict. Evaluations performed by the consultant during the course of grading may result in new recommendations which could supersede these specifications or the recommendations of the geotechnical report. It shall be the responsibility of the contractor to read and understand these specifications, as well as the geotechnical report and approved grading plans. 2.0 Earthwork Observation and Testing Prior to the commencement of grading, a qualified geotechnical consultant should be employed for the purpose of observing earthwork procedures and testing the fills for conformance with the recommendations of the geotechni- cal report and these specifications. It shall be the responsibility of the contractor to assist the consultant and keep him apprised of work schedules and changes, at least 24 hours in advance, so that he may schedule his personnel accordingly. No grading operations should be performed without the knowledge of the geotechnical consultant. The contractor shall not assume that the geotechnical consultant is aware of all grading operations. It shall be the sole responsibility of the contractor to provide adequate equipment and methods to accomplish the work in accordance with applicable grading codes and agency ordinances, recommendations in the geotechnical report, and the approved grading plans not withstanding the testing and observation of the geotechnical consultant. If, in the opinion of the consultant, unsatisfactory conditions, such as unsuitable soil, poor moisture condition, inadequate compaction, adverse weather, etc., are resulting in a quality of work less than recommended in the geotechnical report and the specifications, the consultant will be empowered to reject the work and recommend that construction be stopped until the conditions are rectified. Maximum dry density tests used to evaluate the degree of compaction should be performed in general accordance with the latest version of the American Society for Testing and Materials test method ASTM D1557. 3.0 Preparation of Areas to be Filled 3.1 Clearing and Grubbing: Sufficient brush, vegetation, roots, and all other deleterious material should be removed or properly disposed of in a method acceptable to the owner, design engineer, governing agencies and the geotechnical consultant. - -iv 8840360-04 - - - - - - 3.2 3.3 3.4 3.5 3.6 3.7 The geotechnical consultant should evaluate the extent of these removals depending on specific site conditions. In general, no more than 1 percent (by volume) of the fill material should consist of these materials and nesting of these materials should not be allowed. Processing: The existing ground which has been evaluated by the geotechnica ,l consultant to be satisfactory for support of fill, should be scarified to a minimum depth of 6 inches. Existing ground which is not satisfactory should be overexcavated as specified in the following section. Scarification should continue until the soils are broken down and free of large clay lumps or clods and until the working surface is reasonably uniform, flat, and free of uneven features which would inhibit uniform compaction. Overexcavation: Soft, dry, organic-rich, spongy, highly fractured, or otherwise unsuitable ground, extending to such a depth that surface processing cannot adequately improve the condition, should be overex- cavated down to competent ground, as evaluated by the geotechnical consultant. For purposes of determining quantities of materials overexcavated, a licensed land surveyor/civil engineer should be utilized. Moisture Conditionin : Overexcavated and processed soils should be watered, dried-back, b ended, and/or mixed, as necessary to attain a uniform moisture content near optimum. Recompaction: Overexcavated and processed soils which have been properly mixed, screened of deleterious material, and moisture- conditioned should be recompacted to a minimum relative compaction of 90 percent or as otherwise recommended by the geotechnical consultant. ;;Ehy:y Where fills are to be placed on ground with slopes steeper (horizontal to vertical), the ground should be stepped or benched. The lowest bench should be a minimum of 15 feet wide, at least 2 feet into competent material as evaluated by the geotechnical consultant. Other benches should be excavated into competent material as evaluated by the geotechnical consultant. Ground sloping flatter than 5:l should be benched or otherwise overexcavated when recommended by the geotechnical consultant. Evaluation of Fill Areas: All areas to receive fill, including processed areas, removal areas, and toe-of-fill benches, should be evaluated by the geotechnical consultant prior to fill placement. - - 8840360-04 4.0 Fill Material .- - - - - - -~ - - - - - - 4.1 4.2 4.3 General: Material to be placed as fill should be sufficiently free of organic matter and other deleterious substances, and should be evaluated by the geotechnical consultant prior to placement. Soils of poor gradation, expansion, or strength characteristics should be placed as recommended by the geotechnical consultant or mixed with other soils to achieve satisfactory fill material. Oversize: Oversize material, defined as rock or other irreducible material with a maximum dimension greater than 6 inches, should not be buried or placed in fills, unless the location, materials, and disposal methods are specifically recommended by the geotechnical consultant. Oversize disposal operations should be such that nesting of oversize material does not occur, and such that the oversize material is completely surrounded by compacted or densified fill. Oversize material should not be placed within 10 feet vertically of finish grade, within 2 feet of future utilities or underground construction, or within 15 feet horizontally of slope faces, in accordance with the attached detail. Import: If importing of fill material is required for grading, the import material should meet the requirements of Section 4.1. Sufficient time should be given to allow the geotechnical consultant to observe (and test, if necessary) the proposed~import materials. 5.0 Fill Placement and Compaction 5.1 5.2 5.3 Fill Lifts: Fill material should previously evaluated to receive .._-.. . be placed in areas prepared and fill, in near-horizontal layers approximately b incnes in compacted thickness. Each layer should be spread evenly and thoroughly mixed to attain uniformity of material and moisture throughout. Moisture Conditioninq: blended, and/or mixed, content near optimum. Fill soils should be watered, dried-back, as necessary to attain a uniform moisture Compaction of Fill: After each layer has been evenly spread, moisture- conditioned, and mixed, it should be uniformly compacted to not less than 90 percent of maximum dry density (unless otherwise specified). Compaction equipment should be adequately sized and be either specifi- cally designed for soil compaction or of proven reliability, to efficiently achieve the specified degree and uniformity of compaction. - _ iii _ 8840360-04 - - - - - 5.4 5.5 6.0 - - - - 7.0 - - - - - - - 8.0 Fill Slopes: Compacting of slopes should be accomplished, in addition to normal compacting procedures, by backrolling of slopes with sheepsfoot rollers at increments of 3 to 4 feet in fill elevation gain, or by other methods producing satisfactory results. At the completion of grading, the relative compaction of the fill out to the slope face should be at least 90 percent. Compaction Testing: Field tests of the moisture content and degree of compaction of the fill soils should be performed by the geotechnical consultant. The location and frequency of tests should be at the consult- ant's discretion based on field conditions encountered. In general, the tests should be taken at approximate intervals of 2 feet in vertical rise and/or 1,000 cubic yards of compacted fill soils. In addition, on slope faces, as a guideline approximately one test should be taken for each 5,000 square feet of slope face and/or each 10 feet of vertical height of slope. Subdrain Installation Subdrain systems, if recommended, should be installed in areas previously evaluated for suitability by the geotechnical consultant, to conform to the approximate alignment and details shown on the plans or herein. The subdrain location or materials should not be changed or modified unless recommended by the geotechnical consultant. The consultant, however, may recommend changes in subdrain line or grade depending on conditions encountered. All subdrains should be surveyed by a licensed land surveyor/civil engineer for line and grade after installation. Sufficient time shall be allowed for the surveys, prior to commencement of filling over the subdrains. Excavation Excavations and cut slopes should be evaluated by a representative of the geotechnical consultant (as necessary) during grading. If directed by the geotechnical consultant, further excavation, overexcavation, and refilling of cut areas and/or remedial grading of cut slopes (i.e., stability fills or slope buttresses) may be recommended. Quantity Determination For purposes of determining quantities of materials excavated during grading and/or determining the limits of overexcavation, a licensed land surveyor/civil engineer should be utilized. - iv - - - - - - - -- - - - - - - - CEY EpTH STABILITY FILL / BUTTRESS DETAIL OUTLET PIPE8 4’ 0 NONPERFORATED PIPE. loo’ MAX. O.C. ~IORIZONTALLY. 30’ MAX. O.C. VERTICALLY 1:l OR FLATTER SEE SUEDRAIN TRENCI -______- ___-__-__ __-__-__ ____-_ OWES1 SUSDRAIN SHOULD BE SITUATED A8 LOW A8 POSSIBLE TO ALLOW SUITABLE OUTLET KEY WIDTH AS NOTED ON QRADINQ PLANS 15’ MIN. 8. MIN. / SEE ‘-,“p~EC”O” -I+$&A~ED 3N. ILTER FABRIC NVELOPE MP*=’ ..~“-rl 40N OR APf ‘ROVED 4’ MIN. SEDDINQ 314’-I-112* \ rTED iOUIVALENT)* SUBDRAIN TRENCH DETAIL NOTES: For buttrwa dlmwtrlonr. see gwtochnlcal r~pcrtlpl~ns. Actual dlmenelon~ of buttwan rnd, rubdrrl may be chwwed by the gectechnlc~l CCnwltwtt bwed on field condltionr. T-CONNECTION DETAIL I *IF CALTRANS CLASS 2 PERMEABLE MATERIAL IS USED IN PLACE OF 3/4=-1-l/2* QRAVEL. FILTER FABRIC MAY SE DELETED SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size % Passing 1” 100 3/4” go- 100 3/B” 40-100 No. 4 25-40 No. a 18-33 No. 30 5-15 No. 50 No. 200 ::: Sand Equivalent>75 SUSDRAIN INSTALLATION-SubdraIn pipe rhould be Inrtalled with perforntlonr down M depIcted. At locatlonr recommended by the g~ctechnlo~l~conrult~nt. nonoerforatad pipe should be Instilled SUBDRAIN TYPE-Subdraln type should be Acrylonltrllo Sut~dlene StYrOn* (A.S.9.). Pclyvlnyl Chlorldo (PVC) Or approved oqulvalont. Claee 126,SDR 32.5 l hculd be uwd for maxImum fill depth8 of 36 fee Clara 204SDR 21 should be wed for mwlmum fill doptha of 100 feet. - - -. - - .- - .- - - - - - - I TRANSlTl,ON LOT DETAILS CUT-FILL LOT EXISTING QROUND SURFACE I l- 30” MIN.* =’ ~OVEREXCAVATE AN0 RECOMPACT Y BY THE CONSULTANT ffo J GEOTECHNICAL EXISTINQ GROiJND SURFACE j-l- --- I I-- /,-R&&i I’ UNSUITABLE MATERIAL,- , /’ 5“ - -- MIN. OVEREXCAVATE AND RECOMPACT COMPETENT BEDROCK R MATERIAL EVALUATED BY THE GEOTECHNICAL CONSULTANT *NOTE: *NOTE: Deeper or laterally more extensive overexcavation and Deeper or laterally more extensive overexcavation and reoompaotlon may be recommended by the geoteohnlcal recomoactlon mav be recommended bv the oeotechnical _~~~~ _~.~~~~~~~ ~~, conrultant based on actual field conditioni encountered oonrultant based on actual field conditiona encountered’ and location8 of proposed improvementa and location8 of proposed improvementa - - - - - - - -. - - .- - - - ROCK DISPOSAL DETAIL PlNl8H QRADE I ___-------- ---- ___------ ----- ---------- -- --- ------------ ---- _-------- ----- -------- ---- --- TypicAL PROFILE ALONG WINDROW 1) Rock with maximum dimensions greater than 6 inches should not be used within10 feet vertically of.finiah grade (or 2 feet below depth of lowest utility whichever is greater), and 15 feet horizontally of elope faces. 2) Rooks with maximum dimensions greater than 4 feet should not be utiiized in fills. 3) Rook placement, flooding of granular soil, and fill placement should be observed by the geotechnioai consultant. 41 Maximum sire and spacing of windrowa should be in accordance with the above details Width of windrow should not exceed 4 feet. Windrowa should be staggered vertically (as depicted). 6) Rock should be placed in excavated trenches. Granular soil (S.E. greater than or equal to 30) should be flooded in the windrow to completely fill voids around and beneath rocks. - -~ - - - - - - - -- .-, - .~. - - CANYON SUBDRAIN DETAILS - QROUND SURFACE -_--__--________-___-------------- ___________-________--------------- - - - - - - - - _ _ - - - _ _ - - - - - - - _ -------- - ------- - - :~-Z~c<?<COMPACTE,, FILLr~~~zz~-z~ -- --------------- ---------------- _--__-__-__-___ --------_------- TRENCH aEE BELOW SUBDRAIN TRENCH DETAILS 8’ MIN. OVER a’ YIN. OVERLAP 314.-1-112. CLEI 314’-1-112’CLEAN QRAVEL tStt.%tt. MIN.) PERFORATED PIPE IF CALTRANS CLASS 2 PERMEAI MATERIAL IS USED IN PLACE. OF 314’1-112’ GRAVEL. FILTER FAE MAY SE DELETED DETAIL OF CANYON SUBDRAIN TERMINAL DESIQN FINISH SUBDRAIN TRENCH SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size % Passing 1" 100 3/4" go-100 318" 40- 100 No. 4 X-40 No. a la-33 No. 30 5-15 No. 50 o-7 No. 200 o-3 Sand Equivalent>75 Subdraln should be Conetructed only on COmP.t.nt material a. evaluated by th. 3aotechnloal c0n*ultwlt. SUBDRAIN INSTALLATION Subdrain DIP. Should be Inrtalled wlth perforatIona down . . doplctw At locatIona recommended by the peot~chnlcal consultant. nonperforated pipe should be Installa~ SUBDRAIN TYPE-Subdraln type should be Acrylonitrllo Butrdleno Styrone (A.B.S.1. Polyvinyl Chloride (PVC) Or approved Wjulv~lwtt. Clear 123, SDR 32.S should bs wed tar maxlmum fill depth* Of 36 1e.t. Claw 200,SDR 21 should b. u.ed for m~xlmum till depth* of 100 1.M. - .~- - - - - - - - -. - - - - - - SIDE HILL STABILITY FILL DETAIL EXISTINQ QROUND SURFACE I’ 7 A’ I 0’ >‘- ,I’ A’ I FINISHED SLOPE FACE /’ PROJECT t TO 1 LINE 7 / FINISHED CUT PAD / PAD OVEREXCAVATION DEPTH AND RECOMPACTION MAY BE RECOYYENDEB BY T”E I ~~-- -~~~...- ..-- - -. . .._ QEOTECHNICAL CONSULTANT BASED ON ACTUAL FIELD I CONDITIONS ENCOUNTERED. I NOTE: Subdrain details and key width recommendations to be provided baaed on exposed subsurface conditions - - - - - . - - - - - - KEY AND BENCHING DETAILS FILL SLOPE PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT MATERIAL EXl8TlNQ QROUND SURFACE MATERIAL 22Y%~l DEPTH (KEY) FILL-OVER-CUT SLOPE MATERIAL CUT SLOPE (TO SE EXCAVATED PRIOR TO FILL PLACEMENT) CUT-OVER-FILL SLOPE PRIOR TO FILL PLACEMENT) PROJECT 1 TO 1 LINE FROM TOE OF SLOPE TO COMPETENT NOTE: Back drain may be recommended by the geotechnical consultant based on actual field condition8 encountered. Bench dimension recommendation8 may also be altered baaed on field conditione encountered. _- - - - - - - - - - - - .- - - RETAINING WALL DRAINAGE DETAIL SON. BACKFILL. COMPACTED TO 90 PERCENT RELATIVE COMPACTION* RETAININQ WALL- WALL’ WATERPROOFINQ PER ARCHITECT’S 8PEClFICATIONS FINISH GRADE _--. --- - FILTER FABRIC ENVELOPE -Z~ ‘--- (MIRAFI 140N OR APPROVED EQUIVALENT) * 3/4’-i-112’ CLEAN GRAVEL* 4’ (MIN.) DIAMETER PERFORATED PVC PIPE (SCHEDULE 40 OR ---- EQUIVALENT) WITH PERFORATIONS ORIENTED DOWN AS DEPICTED MINIMUM i PERCENT GRADIENT TO SUITABLE OUTLET SPECIFICATIONS FOR CALTRANS CLASS 2 PERMEABLE MATERIAL U.S. Standard Sieve Size X Passing 1" 100 3/4" 90-100 3/B" 40-100 No. 4 25-40 No. B 18-33 No. 30 5-15 No. 50 o-7 No. 200 o-3 Sand Equivalent>75 \ COMPETENT BEDROCK OR MATERIAL AS EVALUATED BY THE GEOTECHNICAL CONSULTANT *BASED ON ASTM D1667 **IF CALTRANS CLASS 2 PERMEABLE MATERIAL (SEE GRADATION TO LEFT) IS USED IN PLACE OF 3/4*-1-l/2’ GRAVEL, FILTER FABRIC MAY BE DELETED. CALTRANS CLASS 2 PERMEABLE MATERIAL SHOULD BE COMPACTED TO 90 PERCENT RELATIVE COMPACTION l NOT TO SCALE 8840360-04 SLOPE NAINTENANCE GUIDELINES FOR HOhEOWNERS TIPS FOR THE HOMEOWNER - .- .,- - .- - Homesites, in general, and hillside lots, in particular, need maintenance to continue to function and retain their value. Many homeowners are unaware of this and allow deterioration of their property. In addition to his own property, the homeowner may be subject to liability for damage occurring to neighboring properties as a result of his negligence. It is therefore important to familiarize homeowners with some guidelines for maintenance of their properties and make them aware of the importance of maintenance. Nature slowly wears away land, but human activities such as construction increase the rate of erosion 200, even 2,000 times that amount. When we remove vegetation or other objects that hold soil in place, we expose it to the action of wind and water and increase its chances of eroding. The following maintenance guidelines are provided for the protection of the homeowner's investment, and should be employed throughout the year. a) b) cl d) e) f) 9) h) Care should be taken that slopes, terraces, berms (ridges at crown of slopes), and proper lot drainage are not disturbed. Surface drainage should be conducted from the rear yard to the street by a graded swale through the sideyard, or alternative approved devices. In general, roof and yard runoff should be conducted to either the street or storm drain by nonerosive devices such as sidewalks, drainage pipes, ground gutters, and driveways. Drainage systems should not be altered without expert consultation. All drains should be kept cleaned and unclogged, including gutters and downspouts. Terrace drains or Gunite ditches should be kept free of debris to allow proper drainage. During heavy rain periods, performance of the drainage system should be inspected. Problems, such as gullying and ponding, if observed, should be corrected as soon as possible. Any leakage from pools, waterlines, etc. or bypassing of drains should be repaired as soon as possible. Animal burrows should be filled since they may cause diversion of surface runoff, promote accelerated erosion, and even trigger shallow soil failures. Slopes should not be altered without expert consultation. Whenever a homeowner plans a significant topographic modification of the lot or slope, a qualified geotechnical consultant should be contacted. If plans for modification of cut, fill, or natural slopes within a property are considered, an engineering geologist should be consulted. Any over- steepening may result in a need for expensive retaining devices. Undercutting of the bottom of a slope might possibly lead to slope in- stability or failure and should not be undertaken without expert consultation. If unusual cracking, settling, or earth slippage occurs on the property, the homeowner should consult a qualified soil engineer or an engineering geologist immediately. E -i - .- - - 8840360-04 i) The most common causes of slope erosion and shallow slope failures are as follows: a Gross neglect of the care and maintenance of the slopes and drainage devices. l Inadequate and/or improper planting. (Barren areas should be replanted as soon as possible.) o Excessive or insufficient irrigation or diversion of runoff over the slope. l Foot traffic on slopes destroying vegetation and exposing soil to erosion potential. j) Homeowners should not let conditions on their property create a problem for their neighbors. Cooperation with neighbors could prevent problems and also increase the aesthetic attractiveness of the property. Winter Alert - It is especially important to "winterize" your property by mid-September. Don't wait until spring to put in landscaping. landscaping can be done later. You need winter protection. Final Inexpensive measures installed by mid-September Will give you protection quickly that will last all during the wet season. l - l - 0 Check before storms to see that drains, gutters, downspouts, and ditches are not clogged by leaves and rubble. Check after major storms to be sure drains are clear and vegetation is holding on slopes. Repair as necessary. Spot seed any bare areas. Broadcast seeds or use a mechanical seeder. A typical slope or bare areas can be done in less than an hour. * -. a l 0 5 a - - - - - Give seeds a boost with fertilizer. Mulch if you can, with grass clippings and leaves, bark chips or straw. Use netting to hold soil and seeds on steep slopes. Check with your landscape architect or local nursery for advise. Prepare berms and ditches to drain surface runoff water away from problem areas such as steep, bare slopes. Prepare bare areas on slopes for seeding by raking the surface to loosen and roughen soil so it will hold seeds. E - ii 8840360-04 CONSTRUCTION - .- - - - -- l Plan construction activities during spring and summer, so that erosion control measures can be in place when the rain comes. l Examine your site carefully before building. Be aware of the slope, drainage patterns and soil types. Proper site design will help you avoid expensive stabilization work. o Preserve existing vegetation as much as possible. Vegetation will naturally curb erosion, improve the appearance and the value of your property, and reduce the cost of landscaping later. l Use fencing to protect plants from fill material and traffic. If you have to pave near trees, do so with permeable asphalt or porous paving blocks. l Preserve the natural contours of the land and disturb the earth as little as possible. Limit the time in which graded areas are exposed. 0 Minimize the length and steepness of slopes by benching, terracing, or constructing diversion structures. Landscape benched areas to stablilize the slope and improve its appearance. l As soon as possible after grading a site, plant vegetation on all areas that are not to be paved or otherwise covered. TEMPORARY NEASURES TO STABILIZE THE SOIL Grass provides the cheapest and most effective short-term erosion control. It grows quickly and covers the ground completely. To find the best seed mixtures and plants for your area, check with your local landscape architect, local nursery, or the U.S. Department of Agriculture Soil Conservation Service. Mulches hold soil moisture and provide ground protection from rain damage. They movide a favorable environment for starting and growing plants. Easy-to- obtain mulches are grass clippings, leaves, sawdust, bark chips, and straw. Straw mulch is nearly 100 percent effective when held in place by spraying with an organic glue or wood fiber (tackifiers), by punching it into the soil with a shovel or roller, or by tacking a netting over it. Commercial applications of wood fibers combined with various seeds and fer- tilizers (hydraulic mulching) are effective in stabilizing sloped areas. Hydraulic mulching with a tackifier should be done in two separate applications: the first composed of seed fertilizer and half the mulch, the second composed of the remaining mulch and tackifier. Commercial hydraulic mulch applicators - who also provide other erosion control services - are listed under "landscaping" in the phone book. Mats of excelsior, jute netting, and plastic sheets can be effective temporary zrs, but they must be in contact with the soils and fastened securely to work effectively. E - iii - .- - - - - - - Roof draina e can be collected in barrels or storage containers or routed into der boxes and gardens. Be sure to cover stored water so you don't Collect mosquitos. Exiessive runoff should be directed away from your house. Too much water can damage trees and make foundations unstable. STRUCTURAL RUNOFF CONTROLS Even with proper timing and planting, you may need to protect disturbed areas from rainfall until the plants have time to establish themselves. Or you may need permanent ways to transport water across your property so that it doesn't cause erosion. To keep water from carrying soil from your site and dumping it into nearby lots, streets, streams and channels, you need ways to reduce its volume and speed. Some examples of what you might use are: Riprap (rock lining) - to protect channel banks from erosive water flow. Sediment trap - to stop runoff carrying sediment and trap the sediment. Storm drain outlet protection - to reduce the speed of water flowing from a pipe onto open ground or into a natural channel. Oiversion dike or perimeter dike - to divert excess water to places where it can be disposed of properly. Straw bale dike - to stop and detain sediment from small unprotected areas (a short-term measure). Perimeter swale - to divert runoff from a disturbed area or to contain runoff within a disturbed area. Grade stabilization structure - to carry concentrated runoff down a slope. E - iv