Loading...
HomeMy WebLinkAbout; Jones Triplex; Soils Report; 1985-04-23GEOTECHNICAL STUDY JONES TRIPLEX 340 WALNUT AVENUE CARLSBAD, CALIFORNIA PREPARED FOR B. A Worthinq, Inc. 690 Elm Avenue, Suite 204 Carlsbad, California 925108 PREPARED BY Southern California Soil & Testing, Inc. Post Office Box 20627 62530 Rivet-dale Street San Diego, California 92120 April 23, 1985 H. A. Worthing, Inc. SCS.?<T 6521 Cl70 6%) Elm Avenue, Suite 204 Report No. 1 Carl sbad 9 California 92CN:rE SUHJECT: Report of Geotechnical Study, Proposed Jones Triple:.:, 340 Walnut Avenuel Carlsbad, California. Gentlemen: In accordance with YOLW- request we have completed a qeotechnical investigation for the proposed project. We are presenting herein our findincJ and recommendations. The findings of this study indicate that the site is suitable for the proposed development provided the recommendations presented in the attached report are complied with. If you have any quest i on5 af trr revi ewinq the findings and recommendations contained in the attached report. ple37se dc not hesitate to contact thi 5 of fit- -. This oppor’iunit-+ to be of professional service is sincerely appreciated. Respectfully submitted. SOUTHERN CALIFORNIA SOIL b TESTING, F:R/JH/pp CC: (6) Sbmitted SOUTHERN CALIFORNIA SOIL AND TESTING. I N 0. CONTENT Page Introduction and Project Description.......................1 Project Scope..............................................l Findings...................................................~ Site Description......................................~ General Geology............. . . . . . . . . . . . . . . . . . . . . . . . . ..z Geologic Settiny.................................? Tectonic Setting.................................2 Geologic Hazards.................................3 Groundwater...............................*......3 Recommendations and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . ...4 Demolition............ . . . . . . . . . . . . . . ..*..a............ 4 General..........................................4 Deleterious Material.............................4 Abandoned Utilities...............................4 Seepage Pitr and Wells...........................4 Site Preparation..................................4 Huildin~q Fad................................4 Paved Areas.................................5 Surface Drainage............................5 Earthl~Jc,r:::...................................5 Foundaticns...........................................~ General..........................................~ Bearing Capacity.................................5 Lateral Resistance...............................!= Settlement Characteristics.......................6 Expansive Characteristics ..................... ...6 Limitation5 ................................................ . Rrvi ew, Observation and Testing .................... ...6 Uniformity of Condition5 ........................... ...7 Chancre in Scope .................................... ...7 Time Limitations ...................................... 7 Implied Warranty.. . . *. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...7 Client's Responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Field Explorations...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..B Laboratory Testing . . . . . . . . . . ..*...................-......*. 8 Moisture-Density...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..B Classification........................................8 Compaction Test.......................................E Direct Shear Tests....................................9 Consolidation Test....................................9 TAHLES Table 1 Max i ~LUII Pscfroc I:: Accel erati ens PLATES Plate 1 Plot Plan Plate 2 Soil Classification Chart Plate 3-b Trench Lc~r Plate 7 Ma::im~m Dry Density Determination Plate 7 Direct Shear Summary Plate S Cons.olidatinn Load )::ips/sq.ft. APPENDIX Recommended i;radr- Speci F i ca.iion and Speri.31 F’rn.vi-I-ions GEOTECHNICAL STUDY JONES TRIPLEX 340 WALNUT AVENUE CARLSBAD, CALIFORNIA INTRODUCTION AND PROJECT DESCRIPTION This report presents the results of our geotechnical study for a proposed triple:: which is to be located at 340 Walnut Avenue in the City of Carlsbad. It is out- understanding that a two story wood framed structure over an on-grade aqaraqe ic, planned for this site. It is further understood that d minimal amount of grading will be necessary to develop the site. This information was obtained from conversations with OLT client. The 5ite configuration and exoloration location5 are shown on Flate Number 1, of this report. PROJECT SCOPE This investigation consisted of: surface reconnaissance: subsurface explorations: cbtaining representative disturbed and undisturbed samples: labar-atory testing; analysis of the field and laboratory data: research of available sgeol ogi cal literature pertaininq to the site; and preparation of this report. Specifically. the intent of this analysis was to: St) Explore the subsurface conditions to the depths influenced br the proposed construction. b) Evaluate, 5v laboratory tests, the pertinent engineer-in;-, proy~rtiez of the various strata which will infl:xcnce the development, includinca their bearinq c5~c,3,:itiesm exp.3nsik'e rharacteri~%tic:s a11ci settlement zotzntial. C) Define the qenoral yeology at the site including possible qezlogic hazards which could have an effect on the site development. SOUTHERN CALIFORNIA Scl!L AND TESTINS. I N c SC’3.T 8521070 April 22, 1995 Page 2 d) Develop soil engineering criteria for site grading. e) Determine potential construction difficulties and provide reccmmnndations concerning these problem-;. f) Recommend an appropriate foundation systeni for the type of structures anticipated and develop soi 1 engineering dezi qn criteria for the recommended fnundation design. FINDINGS SITE DESCRIPTION The subject site is a rectangul at- shaped lot located at 340 Walnut Avenue in the City of Carlsbad, California. The site is bounded by Walnut Avenue on the south and residential housing on al 1 other boundaries. Topographical 1 y the site is relatively level and vegetation consist.5 of mature avocado trees, a palm tree, 1 andscaped shrubbery and I awn ~jrasses. Structures consistiny of a wood framed single-story house and garage occupy the central portion of the site. A masonry bloc):: retaining wall, which ranger; up to 8 feet in height. exists along the northern property line. Also a wooden fence with a concrete base is located along the eastern and western property boundar i es. Utility service to the site is from Wcilnut Avenue. GENERAL GEOLOGY AND SUBSURFACE CONDITIONS GEOLOGIC SETTING AND SOIL DESCRIPTION: The subject site is located in the Coastal Plains Physioyraphic Province oi San Diego County and is underlain by auaternary aged terrace depot-its and associated residuum Specific soil conditions as encountered in our esplnration consists of a reddi zh brown silty sand, of which the upper most 1.5 to aoproximateii 2.5 feet were porous, loose and humid in consistency. Underlying the above sw-f ace 501? 5 the terrace deposits became humid to moist and medium dense in cone.istency. TECTONIC SETTING: A review of avai 1 able grol oqi c maps indicates the subject site to be located approximate1.y 5 miles east of the Rose Canyon Fault Zone. The Rose Canyon Fault Zone is a series of northwest trending f au1 ts of Ouaternary age that is currently classified a5 pntentially active. rither than active according to the c:-iteria of the California Divizi:x 05 Mi net- and Geol os3y. This classification is bssed on the ls,,z!:. 0.i concl usi ve evi dents 2’~ verify Holocene movement al =nsr; thj.5 f ,s.ul.l- zone. N 113 +_?i::t tr,?ces h .s, y e been rnaoped throwih ‘or immediat.zlv adjacent to. t h e .= LI b 1 e c t 5~i te and a ‘5 li t- ~5 li + 12 reconnaissance yieldei no evidence 0.5 fzultint> at the site. SCS$<T 8521 1:!70 April 2s! 1?83 F’ape ; It c,hould be recogni:ed that much of Southern California i-5 characterised by major, active fault zones that could possibly affect the subject site. The nearest o.f these are the Elsinore Fault Zone, located appro::imately 30 mile5 to the northeast. and the Coronado Banks Facrl t Zone. located approximately 20 miles to the southwest. GEOLOGIC HAZARDS The subject site can be considered to be relatively free of nqeolo?ic hazards. Potential hazards such as tusnamis, seiches, liquefaction, or 1 andsl i di ng should be considered to be negliyible or nonexistent. The most likely major geologic hazard to affect the site is eroundshaking ~7s a result of movement alon’ one of the major active f au1 t zones mentioned previously. The maximum bedrock:: accelerations that would be attributed to a maximum probable earthquake occurring along the nearest portion of selected f au1 t zoner, that con1 d affect the site are summarized in the following table. TABLE 1 Ma:.: i mum Maxi mum Fault Probable Bedrock zone Cl assi f Fg_a&ign Distance -------- EarthqEaig &celeration Rose Canyon Potent i al 1 y 5 mile5 4. 1:) magnitude 0.38 ‘2 Active Elsinore &cti “F 25 miles 7.3 magnitude !:I. -“I:> rg Coronado Banks Act i :‘E 29 mi 1e5 5.0 mas;initude !:! , 1 2 ‘3 Based on the current fault zone classification and the maxiinum bedrock:: accel erati on5 capable of developing. it is recommended that the Elsincre Facil t Zone be consi dererJ the design earthquake source for the subject development. Construction in accordance with the minimum standards of the Uniform Building Code and the *Jorerninq -7gencv should minimize pntenti al damage due to seismic activity{. GROUNDWATER: No groundwater was. encountered durinmj our- subsurface e:.rplorc7ti.>n and we do nat anticipite an.‘,’ ma,or rI,!-oilndwater related problems. pi thb=r d ii r i “$2 c,r after construct~.on. t+xwe.~et-. i t ihoul d be r~scn\y,:;:e,, th3t mi 2cr ‘>roundwatet- seepadze prob! ems may occur after develnpment of a site even where none wet-e present before deyel opment. Those are usual I y minor phenomena and are o~ften the result of a n alteration of the permeability characteristics of the soil, and alteration in drainasje patter-nr and an increased in irrigation water. Based on the permrabilit,y characteristics of the soil SCSP<T 852 1070 April 23, 1995 Page 4 and the anticipated usage of the development, it is our opinion that any seepage problems which may occw- will be minor in extent. It is further out- opinion that these problems can be most effectively corrected on a" individual basic, if and when t hey develop. RECOMMENDATIONS AND CONCLUSIONS DEMOLITION GENERAL: As previously mentioned, this site has been subject to past developments and presently eupports residential structures and their associated improvements. Demolition of these facilities will result in a considerable amount of debris and disturbed soil. The recommendations presented in the following sections are provided for these demolition operations and these recommendations should be complied with thoroughly. Any unforeseen condition encountered during demolition should be brought to oui- immediate attention. DELETERIOUS MATERIALS e, HARD CONSTRUCTION DEBRIS: All deleterious materials and hard construction debris qenerated from the clearing and demolition operatians should be legally disposed of off-site. ABANDONED UTILITIES: All existing underground utilities whicl-i at-e to be abandoned should be properly capped off and removed. The depressions resulting from these removals should be backfilled with compacted soil deneified to at least 90% of maximum dry density. SEEPAGE PITS AND WELLS Although not encountered. it is possible that some old seepage pits and/or wells may e:.: i st on-site. Should they be encountered, we recommend that they be backfilled with crushed rock and be cut off at least 5 feet from finished gqrade. A 12 inch thick concert cap. reinforced with No. 3 bars at 12 inches on center5, each way, should then be constructed over the top of the seepage pit or we1 1. SITE PREPARATION BUILDING FAD: Due to the loose nature of the near surface soils at this site. we recommend that they be removed to firm natural sjrc;und arid 3e stockpiled for fcltcrre use. Fit-m natural *around is defined 3s native c-oil which possesses a in-situ density equal to "r tqre3ter than 85X of it maximan dry{ density. The soils exposed at the bsse a-F tt1i 5 excavation shoi!ld then be scar-if ied 12 inches. be lmoisture conditioned tu at 1ea5t 37 &. over optimum and dznsi+ied to a mlnlmclm of 9 0 i: trelati.ve compaction. The c-tackpiled 5oil5 and any additional fill may then be replaced in eight inch lifts. moi stcre treated and compacted as outlined above. The horizontal limits of these recommendations sho,!d include the area within a perimeter of 5 SCS?J- 852 11:,70 April 2X5 1985 Page 5 feet outsi de of the proposed building. Based on the findings of this study, it i 5 est i mated that the maxi mum depth 0.f removal and recompaction will be on the order of 2.5 feet. PAVED AREAS: We recommend that the subgrade soi Is beneath al 1 a!-0~7s to be paved should be scarified to a depth of at least 12 inches. The soils within this depth should then be moisture conditioned to at least 2% over optimum and densified to a minimum of 90X of maximum dry density. SURFACE DRAINAGE: We recommend that al 1 surface drainage be directed way from the proposed structure and that pondinq of water not be allowed adjacent to its foundation. EARTHWORK: Al 1 earthwork and grading contemplated for site preparation should be accomplished in accordance with the attached Recommended Grading Specification5 and Special F’rovi si on=.. All special site preparation recommendations presented in the sections above will supersede those in the Standard Recommended Grading Specifications. Al 1 embankments, structural f i I.1 and fill should be compacted to a minimum of 90% at slightly over- opti mum moisture content. All utility trench backf i 11 should be compacted to a minimum of 90% of its maximum dry density. The maximum dry density of each soil type should be determined in accordance with A. S. T. M. Test Method D15;7-78, Method A ot- C. FOUNDATIONS GENERAL: It is out- opinion that the proposed structure maybe supported by spread f ooti nqs provided the recommendations contained in this report are followed. Al 1 footings should be founded at least 18 inches below lowest adjacent finished #grade with a minimum width of 12 inches. We further recommend that all continuous footings be reinf arced with at lea.st one No. 4 bar top and bottom. HEARING CAFACITY: The allowable soil bearing pressure for the soils prepared a\g recommended herein is expressed by the followinq formulas far continuous, square, and circular spread f ooti ng5: Continuous Footings: Square Foot i rigs: Circul at- Fonti ng_ Where: 9 = 1 . 05 + I:,. 40 D + 0. 15 B 9 = 1.2,s + r:r.w I? + 0.1” B 9 = 1.26 + l.l.‘w D + ci.09 5 q = Allowable soil bearing pressure as limited in shear in kips per square foot for full live and dead loads. D = Footing depth below adjacent grade in feet. SCS,?rT 1357 11:riO April 2;: 1985 Page 6 H = Footing width or diameter in feet, The db@VE? allowable stresses may be increased by one-third for wind and/or seismic loading and should be decreased by one- fourth for dead load only. The allowable bearing pressure in ):ips pet- squat-e foot for live and dead load-, for the minimum size footinsas recommended above are a5 fc?llows: Continuous Footings Square Footings Circular Footings The allowable bearing pres,sures for other size footings may be computed from the above formulas. We recommend, however, that the maximum allowable soil bearing pressure be limited to 3.0 kips per square foot. LATERAL RESISTANCE: Resistance to lateral loads may be provided by friction at the base of the footing and by passive pressure against the adjacent soil. For concrete footings on compacted soil, a coefficient of friction of 0.34 may be used. For calculating passive pressure, a" equivalent fluid unit weight of 225 pounds per cubic foot may be used for compacted soil. Passive pressure should not exceed 1 XW pounds per square foot. When combining frictional and paksive resistance, the latter should be reduced by one-third. SETTLEMENT CHARACTERISTICS: The anticipated total and/or differential settlements for the proposed structure may be considered to be w i t h i i7 tolerable limits provided the recommendations presented in this report are followed. EXPANSIVE CHARACTERISTICS: The prevailing foundation soil5 were found to be nondetrimentally expansive and will not require special consideration and/or design. LIMITATIONS REVIEW, OBSERVATION AND TESTING The recommendations presented in this report are contingent upon out- review of finai plans and specifications. The soil enqineer and enginrori"~~ ,;eo!ol>ist should review and k,erify the compliance of t.he final sa;rs.dinr 2 plan with this report and with Chapter 7i:) nf tk Ciniform-Suilding Code. It is recommended that the soil and foundation engineer be retained to provide continuous soil engineering services during the earth work: operations. This ir to observe compliance with the desiq" concept-,. specifications or recommendations and to allow derQn chsnpes in the event that subsurface conditions differ from that anticipat'zd prior to start a+ construction. SIX&T El';?1 070 &A April 73, 1985 Page 7 UNIFORMITY OF CONDITIONS The recommendations and np1nions expressed in this report ref1ec.t our best estimate o.f the project requirements based on an evaluation of the subrurface soil conditions encountered at the subs~~r.face e;:ploratian location5 and the assumption that the soil conditions do not deviate appreciably from those encountered. It should be recognired that the performance of the foL{ndations and/or cut and fill sloper may be influenced by undisclosed or unforeseen variations in the soil conditions that may occur in the intermediate and unexplored areas. A"Y unusual conditions not covered in this report that may be encountered during site development should be brought to the attention of the soil5 engineer so that he may make modifications if necessary. CHANGE IN SCOF'E This office should be advised of any changes in the project scope or proposed site gradiny so that it may be determined if the recommendations contained herein are valid. This should be verified in writing or modified by a written addendum. TIME LIMITATIONS The findings of this report are valid as of this date. Changes in the condition of a property can, howwet-, occur with the passage of time, whether they be due to natural processes or the work of man on this or adjacent properties. In addition, changes in the State-of-the-Art and/or Government Codes may occur. Due to such chan'aes, the findings of this report may be invalidated wholly ot- in part by chanqes beyond our control. Therefore, this report should not be relied upon after a period of two years without a review by L(E~ verifying the validity of the conclusions and recommendations. IMPLIED WARRANTY This report has been prepared for the exclusive use of H. A. Worthing, Inc. for specific application to the subject project in accordance with generally accepted soil and foundation en8Jinerring practices. No other warranty, expressed or implied are made. CLIENT'S RESPONSIBILITY It is the responsibilit,?. of the B . A . Northing Inc., or its representatives to ensnre tha.t the information and recommendations contained herein are brought to the attention of the engineer and archirect for the project and incorporated into the project's plans and specifications. It irj further his responsibility to take ths necess;ary ITI~~~L~-EE, to insure that SCS&T 8521071:l April 23, 1985 Paye E the contractor and his subcontractors carry out such recommendations durin+ construction. FIELD EXPLORATIONS Few- subsurface exploration5 were made at the locations indicated on the attached F'late Number 1 on April 4, 1985. These explorations consisted of trenches dug by means of a backhoe. The field work was conducted under the observation of our engineering geology personnel. The explorations wet-e carefully 1 oqqed when made. These loqs are presented on the followiny F'late Numbers 3 through 6. The soils are described in accordance with the Unified Soils Classification System as illustrated on the attached simplified chart. In addition, a verbal textural description, the wet COlOr, the apparent moisture and the density or consistency are presented. The density or ~qranular material is given ae. either very loose, loose, mediLlm dense, dense or very dense. Disturbed and "undisturbed" sample5 of typical and representative soils were obtained and returned to the laboratory for testing. LABORATORY TESTING Laboratory tests wet-e performed in accordance with the agenerally accepted American Society for Testing and Materials (A.S.T.M.) test methods or suggested procedures. A brief description of the tests pet-farmed is presented below: a) MOISTURE-DENSITY: Field moisture content and dry density were d~etermined for representative undis- turbed samples. This information was an aid to classification and permitted recognition of variations in imaterial consistency with depth. The dry Llnit weight is determined in pounds per cubic foot, and the field moisture content is determined as a percentage of the soil's dry weight. The results are summarized in the trench logs. b) CLASSIFICATION: Field classifications were verified in the l~borat.ry by visual examination. The final c-oil c?assificstion.z are in accordance with the Unified Scil Classification System. c! COMPACTION TEST: 'The maximum dry density and optimum moisture ccnten: of typical soils were determined in the laboratory I" accordance with A.S.T.M. Standard Test D-15‘7-78. Method A. The results of these tests are presented CT. the following Plate Number 7. April 23, 1985 Paye 5 e) DIRECT SHEAR TESTS: Direct shear tests were pet-f armed to determine the failure envelope bared on yield shear strength. The shear box eras designed to accommodate a sample havi nag A diameter of r‘. ,775 inches or Z.;!.) inches and a hei 4qh.t of 1 . 0 inch. Samples were tezted at different vertical loads and at saturatnd moisture content. The shear stress was applied at A constant rate of strain of approximately I:) 1); in,zhe=4 per minute. The results of these tests are presented on attached F’late Number 7. f) CONSOLIDfiTION TEST: Single point consolidation tests were performed on selected “undisturbed” samples. The consolidation apparatus was desiqned to accommodate a i-inch high by 2.5 7%inch or 2. 5ol:l- inch-diameter soil sample laterally confined by a brass ring. F;orous stones were placed in contact with the top and bottom of the sample to permit the addition or release of pore fluid during testiny. The percent consolidation for each load is reported as the ratio of the amount of vertical compression to the original one-inch ramp1 e height. The test samples were inundated at some point in the test cycle to determine their behavior under the anticipated footiny load a6 soil moisture increases. The results of these tests are presented on PI. ate Number 8. Z”““, I’,,! I/. 1: ::, , 2 ; : i ;;i: = ;z!& 0 -i, / /. ; L- buJ~ I rLLN-nw, , i’ !’ 11 =‘J / ,%FKI nG SmLE ., ~:zi x lie+ ., x,~I,c,i*YIIIq ’ -r: j I~) /I; I -I i - = r?-: -- ‘;,~z;; wt-42, ,’ , + ,! :I id m,i I SUSSURFACE EXPLORATION LEGEND r Sil?5 CES: s;:i39 YCZe :>.l.i ha!.: Of c51.5e tr2czicn it r:llle: :5an N.3. 4 sieve si;e. 5x:25 ‘2x5 FIS’35 (;2-reci131r 2zc_il: cf t;;.er) I’. ‘~~:;~ Gz:-T::T,. .XGZe. :?,a> haI5 oi rar+.-ial is w ear. .va. 200 rievn s:zt. Iz^r~l;.ic silt* ?.nC ‘Ye=, fi.7e ra.mzs. z=c:< Llsur. rar.+y nil: 0: c’rve”-sil:-land Dilr2res uii>‘.‘l;>: +s:.- i;i‘.:, Txr;lnic c’lys 05 bi5h ~ie,rici‘y, fdZ clays. C~~~.-.lC clap c: ce2l.z co.hi;b 21 _ -3s:;ci::/. ?*a: 1x< ccie; hi;li:, CjXiC SOill. 7 - Sjctsr level at iS,z of e*cavz:ion or as icdicztsd US - U-disturbed, driven ring smple or t-be szzp1e CK - Unfisturbzd ctxni: sxy112 5 :> - C:;lk SX?l? SOUTHZ~N CALIFZ;iNIA SOIL & TESTING, INC. e.zlso OIVEFIOZILE m7EltET BAN 03tECIa. CnLlFOPNli maica 9Y DATE RRR 4-19-85 JC3 NO. QG31n7n I m;l+a N” 7 I i 5 4 5 6 1 1 - -6 !-c I- C - SM - rRENCH NUMBER 1 FLEVATION DESCRIPTION Reddish Brown, SILTY SAND (Terrace Deposits) Humid Loose Medium Dense 113.7 119.9 117.5 5.4 a5 6.2 a9 4.6 88 SOUTHERN CALIFORNIA SOIL & TESTING,INC. z bp : ; TRENCH NUMBER 2 ‘> c ; :: b 0 z -7 = ,2 ztC w - z E= v, ;p - - z:: z- E+ ELEVATION 2 $; z m w ;% ;; L E ,‘;;a 5: : CJ? 5 z 4 I F$=K 0 g 6; CI Z” 0 3 z z 0 x 0 “0 DESCRIPTION ” u SM Reddish Brown, Humid Loose l- SILTY SAND - CK (Terrace Deposits) 109.3 4.9 82 2- Medium Dense 3- CK Moi~st 117.0 7.4 a7 4- 5- - CK 6 SM Light Reddish Brown, Humid Dense 7- SILTY SAND CK a- 9- 16 SOUTHERN CALIFORNIA SUBSURFACE EXPLORATION LOG SOIL & TESTING,INC. LOGGED BY: JH DATE LOGGED: 4-4-85 JOE NUMBER: 8521070 Plate No. 4 : = E z 0 1 2, 3. 4. 5. SM TRENCH NUMBER 3 ELEVATION DESCRIPTION Reddish Brown, SILTY SAND (Terrace Deposits) Moist Loose Medium Dense a9 w- ,“I- z ZY E 5 z 0 ” 1 2 3 4 5 6 :K :K :K SM rRENCH NUMBER 4 FLEVATION - DESCRIPTION Reddish Brown, SILTY SAND (Terrace Deposits) Humid Loose Medium Dense 110.5 120.0 3.7 5.3 75 89 SOUTHERN CALIFORNIA SOIL & TESTING,INC. DIRECT SHEAR TEST RESULTS DESCRIPTION I I I MAXIMUM DENSITY and OPTIMUM MOISTURE CONTENT ASTM 1557-78 METHOOL!- DESCRIPTION /‘1> 8OUTHERN CALIFORNIA -- SOIL & TEETINQ, INC. BY . ..cJ II”.mDAL. .T”I.T RRR DATE 4-16-85 ../ - - -. -. - ^ - - _ - - I _, . _ _ _ _ _ I I SINGLE POINT CONSOLIDATION TEST RESULTS SOUTHERN CALIFOkNlA SOIL & TESTING, INC. .PzlD p,Y.nDIILI! rnTPLC7 .PN q I,OP* CnLlFOFINlA .aeao BY IIAE RRR 4-16-85 PROPOSED JONES TRIPLEX, 340 WALNUT AVENUE, CARLSBAD RECOMMENDED GRADING SPECIFICATIONS - GENERAL PROVISIONS GENERAL INTENT The intent of these specifications is to establish procedures for clearing, compacting natural ground, preparing areas to be filled, and placing and compacting fill soils to the lines and grades shown on the accepted plans. The recommendations contained in the preliminary soil investigation report and/or the attached Special Provisions are a part of the Recommended Grading Specifications and shall supersede the provisions contained hereinafter in the case of conflict. These specifications shall only be used in conjunction with the soil report for which they are a part. No deviation from these specifications will be allowed, except where specified in the soil report or in other written communication signed by the Soil Engineer. OBSERVATION AND TESTING Southern California Soil and Testing, Inc., shall be retained as the Soil Engineer to observe and test the earthwork in accordance with these specifications. It will be necessary that the Soil Engineer or his representative provide adequate observation so that he may provide an opinion that the work was or was not accomplished as specified. It shall be the responsibility of the contractor to assist the soil engineer and to keep him apprised of work schedules, changes and new information and data so that he may provide these opinions. In the event that any unusual conditions not covered by the special provisions or preliminary soil report are encountered during the grading operations, the Soil Engineer shall be contacted for further recommendations. SCS&T 8521070 April 23, 1985 Appendix, Page 2 If, in the opinion of the Soil Engineer, substandard conditions are encountered, such as; questionable or unsuitable soil, unacceptable moisture content, inadequate compaction, adverse weather, etc., he will be empowered to either to either stop construction until the conditions are remedied or corrected or recommend rejection of this work. Test methods used to determine the degree of compaction should be performed in accordance with the following American Society for Testing and Materials test methods: Maximum Density & Optimum Moisture Content - A.S.T.M. D-1557-78. Density of Soil In-Place - A.S.T.M. D-1556-64 or A.S.T.M. D-2922. All densities shall be expressed in terms of Relative Compaction as determined by the foregoing A.S.T.M. testing procedures. PREPARATION OF AREAS TO RECEIVE FILL All vegetation, brush and debris derived from clearing operations shall be removed, and legally disposed of. all areas disturbed by site grading should be left in a neat and finished appearance, free from unsightly debris. Any abandoned buried structures encountered during grading operations must be totally removed. All underground utilities to be abandoned beneath any proposed structure should be removed from within 10 feet of the structure and properly capped off. The resulting depressions from the above described procedures should be backfilled with acceptable soil that is compacted to the requirements of the Soil Engineer. This includes, but is not limited to, septic tanks, fuel tanks, sewer lines or leach lines, storm SCS&T 8521070 April 23, 1985 Appendix, Page 3 drains and water lines. Any buried structures or utilities not to be abandoned should be investigation by the Soil Engineer to determine if any special recommendation will be necessary. All water wells which will be abandoned should be backfilled and capped in accordance to the requirements set forth in the Geotechnical Report. The top of the cap should be at least 4 feet below finish grade or 3 feet below the bottom of footing whichever is greater. ,The type of cap will depend on the diameter of the well and should be determined by the Soil Engineer and/or a qualified Structural Engineer. When the slope of the natural ground receiving fill exceeds 20% (5 horizontal units to 1 vertical unit), the original ground shall be stepped or benched. Benches shall be cut to a firm competent soil condition. The lower bench shall be at least 10 feet wide or 1 l/2 times the the equipment width which ever is greater and shall be sloped back into the hillside at a gradient of not less than two (2) percent. All other benches should be at least 6 feet wide. The horizontal portion of each bench shall be compacted prior to receiving fill as specified hereinbefore for compacted natural ground. Ground slopes flatter than 20% shall be benched when considered necessary by the Soil Engineer. After clearing or benching, the natural ground in areas to be filled shall be scarified to a depth of 6 inches, brought to the proper moisture content, compacted and tested for the minimum degree of compaction in the Special Provisions or the recommendation contained in the preliminary soil investigation report. All loose soils in excess of 6 inches thick should be removed to firm natural ground which is defined as natural soils which possesses an in-situ density of at least 85% of its maximum dry density. SCS&T 8521070 FILL MATERIAL April 23, 1985 Appendix, Page 4 Materials placed in the fill shall be approved by the soil engineer and shall be free of vegetable matter and other deleterious substances. Granular soil shall contain sufficient fine material to fill the voids. The definition and disposition of oversized rocks, expansive and/or detrimental soils are covered in the soils report or Special Provisions. Expansive soils, soils of poor gradation, or soils with low strength characteristics may be thoroughly mixed with other soils to provide satisfactory fill material, but only with the explicit consent of the soil engineer. Any import material shall be approved by the Soil Engineer before being brought to the site. PLACING AND COMPACTION OF FILL Approved fill material shall be placed in areas prepared to receive fill in layers not to exceed 6 inches in compacted thickness. Each layer shall have a uniform moisture content in the range that will allow the compaction effort to be efficiently applied to achieve the specified degree of compaction. Each layer shall be uniformly compacted to a minimum specified degree of compaction with equipment of adequate size to economically compact the layer. Compaction equipment should either be specifically designed for soil compaction or of proven reliability. The minimum degree of compaction to be achieved is specified in either the Special Provisions or the recommendations contained in the preliminary soil investigation report. When the structural fill material includes rocks, no rocks will be allowed to nest and all voids must be carefully filled with soil such that the minimum degree of compaction recommended in the Special Provisions is SCS&T 8521070 April 23, 1985 Appendix, Page 5 achieved. The maximum size and spacing of rock permitted in structural fills and in non-structural fills is discussed in the soil report, when applicable. Field observation and compaction tests to estimate the degree of compaction of the fill will be taken by the Soil Engineer or his representative. The location and frequency of the tests shall be at the Soil Engineer's discretion. When the compaction test indicates that a particular layer is less than the required degree of compaction, the layer shall be reworked to the satisfaction of the Soil Engineer and until the desired relative compaction has been obtained. Fill slopes shall be compacted by means of sheepsfoot rollers or other suitable equipment. compaction by sheepsfoot rollers shall be at vertical intervals of not greater than four feet. In addition, fill slopes at ratios of two horizontal to one vertical or flatter, should be trackrolled. Steeper fill slopes shall be over-built and cut-back to finish contours. Slope compaction operations shall result in all fill material six or more inches inward from the finished face of the slope having a relative compaction of at least 90% of maximum dry density or that specified in the Special Provisions section of this specification. The compaction operation on the slopes shall be continued until the Soil Engineer is satisfied that the slopes will be stable in regards to surficial stability. Slope tests will be made by the Soils Engineer during construction of the slopes to determine if the required compaction is being achieved. Where failing tests occur or other field problems arise, the Contractor will be notified that day of such conditions by written communication from the Soil Engineer in the form of a daily field report. SCS&T 8521070 April 23, 1985 Appendix, Page 6 If the method of achieving the required slope compaction selected by the Contractor fails to produce the necessary results, the Contractor shall rework or rebuild such slopes until the required degree of compaction is obtained, at no additional cost to the Owner or Soils Engineer. CUT SLOPES The Engineering Geologist shall inspect all cut slopes excavated in rock or lithified formational material during the grading operations at intervals determined at his discretion. If any conditions not anticipated in the preliminary report such as perched water, seepage, lenticular or confined strata of a 'potentially adverse nature, unfavorably inclined bedding, joints or fault planes are encountered during grading, these conditions shall be analyzed by the Engineering Geologist and Soil Engineer to determine if mitigating measures and necessary. Unless otherwise specified in the soil and geological report, no cut slopes shall be excavated higher or steeper than that allowed by the ordinances of the controlling governmental agency. ENGINEERING OBSERVATION Field observation by the soil Engineer or his representative shall be made during the filling and compacting operations so that he can express his opinion regarding the conformance of the grading with acceptable standards of practice. The presence of the Soil Engineer or his representative or the observation and testing shall not release the Grading Contractor from his duty to compact all fill material to the specified degree of compaction. SCS&T 8521070 SEASON LIMITS April 23, 1985 Appendix, Page 7 Fill shall not be placed during unfavorable weather conditions. When work is interrupted by heavy rain, filling operations shall not be resumed until the proper moisture content and density of the fill materials can be achieved. Damage site conditions resulting from weather or acts of God shall b repaired before acceptance of work. RECOMMENDED GRADING SPECIFICATIONS - SPECIAL PROVISIONS The minimum degree of compaction to be obtained in compacting natural ground, in the compacted fill, and in the compacted backfill shall be at least 90 percent. Detrimentally expansive soil is defined as soil which will swell more than 3 percent against a pressure of 150 pounds per square foot from a condition of 90 percent of maximum dry .density and air dried moisture content to saturation. Oversized fill material is defined as rocks or lumps over 6 inches in diameter. At least 40 percent of the fill soils shall pass through a No. 4 U.S. Standard Sieve. TRANSITION LOTS: Where transitions between cut and fill occur within the proposed building pad, the cut portion should be undercut a minimum of one foot below the base of the proposed footings and recompacted as structural backfill.