Loading...
HomeMy WebLinkAboutCT 72-34; RANCHO LA CUESTA; GEOLOGIC GRADING REPORT; 1976-10-19• • • t. • \. • • • • •• • FINAL ENGINEERING GEOLOGIC GRADI NG REPORT Tract 72-34, lots 46-50~ 100-105; 127-129; and 134, (Unit.2), in the City of Carlsbad, California for Newport Shores Builders October 19, 1976 Pacific Soils Engineering, Inc. Irvine, California C -r ~1 :t~3L/ £1',1££111118 . ['xl/it;ls /fy-/f f)fiffe liEd (j) • • • • • • • • • • .' PACIFIC S'OILS E'NGINEER'ING. INC. 17921 SKY PARK CIRCLE, (SUITE G) IRVINE, CALIF. 92707 TELEPHONE: (7l4) 557-9450 Newport Shores Builders P.O. Box A Huntington Beach, CA 92648 Attention: Subject: Gentlemen: Mr. Mike Jager Final Engineering Geologic Grading Report; Tract 72-34, Lots 46-50 incl., '10D-105 incl., 127-]29 incl., & 134 (Unit 2), in the City of Carlsbad, California L.A. COUNTY OFFICE 1402 W. 240th Street Harbor City,Ca. 90710 (213) 325-7272 or 775'6771 VENTURA COUNTY OFFICE Post Office Box 75 Thousand Oaks, Ca. 91'360 (213) 889-9919 (805) 495-6513 Octobel' 1-9, 1976 Work Order l00236A This final geologic report for the subject'tract is submitted in accordance with the requirements of the City ,of Carlsbad. Geologic data ate plotted on the plan included with the companion Project Grading Report. A buttress fill Was required for support qf the street cut slope at the side (southwe~t) of Lot 50. ,Based on our inspection of geologic conditions of the site, the subject lots are satisfactory for the intended use from a geologic point of view. Respectfully submitted, PAC!FIC SOl LS ENGI NEERI NG, INC. Reviewed by: 62062kf&s REX P. KETTER, Vice President Dist: (10) Addressee REL:RPK/vll • •• • • • • • • • • • PACIFIC SOILS ENGINEERING, INC. 17921 SKY PARK CIRCLE (SUITE G) IRVINE, CALIF. 92707 TELEPHONE: (714) 557-9450 Newport Shores Builders P.O. Box A Huntington Beach, CA 92648 Attention: , Subject: Reference: Mr. Mike Jager Project Soil Engineering Grading Report; T rect 72-34, Lots 46-50 i ncl ., 100-105 inel., 127-129 i,ncl., and 134 (Unit 2), in the City of Carlsbad, California Preliminary Soil Engineering and Engineering Geo logic Report and Engineering Geofogic and Soil Engineering Review of,Grading Plan for Tract No .• 72-34, dated July 5, 1974 L.A. COUNTY OFFICE 1402 W. 240th S~reet Harbor City, Ca. 90710 (213) 325·7272 or 775-67.71 VENTURA. COUNTY OFFICE Post Office Box 75 Thousand Oaks, Ca. 91360 . (213) 889-9919 (805) 495·6513 October 19, 1976 Work Orderl00236A by Pacific Soils Engi,neering, Inc. {W.0.1 00236). Gentlemen: This report presents soil engineering data and test results pertaining to the placement of compacted earth fill on' the subject property. Foundation criteria are also included in this report for the subject residential lots 46-50; inclusive; 100-105,inclusive; 127-129 i in.c'lusive; and 134. All fills, cuts or processing of original ground under the purview of this report have been completed under our inspection or accepted by this fi~, and are in compliance with, F .H.A. criteria and the Grading Code of the City of Carlsbad, C<:tliforni6. All work under our purview was accomplished in accordance with the IIEarthquake Specifications'i, contained in the above-referenced investigation report. ;" '(j)- • • • • • • • • • • • October 19, 1976 Work Order 100236A Page Two Completed work has been reviewed and is consi.dered suitable for the construction now planned. All slopes are considered grossly and surficially stable and will remain so under normal conditions. Compaction test results are presented in Table I, and approximate locations of tests are shown on the enclosed grading plan (2 sheets). Also shown on the plan are locations of tests taken in adjacent areas. These test results will be submittecl in future 'grading reports, as these areas are comp,leted, o~ have been submitted in previous reports. Laboratory Standard: ASTM:D 1557--70T % Swell1r Soil Type Opt. Mois. (%) Max. Dry Density (lbs ./cu .ft .) 650psf ASCE D -Clayey Sand 12.5 11S.0 0.1 ND E -Clayey Sand 13.5 115.5 NDS F -Clayey Sand 15.0 113.0 0.0 ND G -Sand' 15.0 108.5 ND ND H -Clayey Sand 15.5 111.5 ND 4 1-Sand' 13.0 117.0 ND ND J -Clayey Sand 13.0 116.5 ND ND * -Swell tests were remolded in a one-inch high ring to 90 percent relative compaction uti lizing materia I at optimum moisture for samples to be surc harged at 650psf. Samples were,inundated for 24-hours and then amount of swell was recorded. ASCE denotes in accordance with ASCE Expansion Index Test. ND denotes not determined. ' 1 • Prior to the placement of compacted fill, the exposed natural surface was scarified, watered as necessary and compacted ino:;place, suitahle to receive fiJI. Where necessary, alluvial materials in canyon swale bottoms were removed t-o either in-place bedrock, or competent natural soils. 2. Fill conSisting of the above soils types was then placed in thin lifts, watered as , p,ACIFIC SOILS ENCIINEERI""~. INC. • • • • • • • • • • • October 19, 1976 Work Order 100236A Page Three necessary and compacted in-place to a mi'nimum of 90 percent of the laboratory standard utilizing tractor-drawn sheepsfoot type rollers and heavy earth moving equipment. Each fill was treated in a like manner. 3. Fill placed on slope gradients st~eper than 5-horizontal to 1-vertical was keyed and benched into bedrock. The upper soils were stripped and/or benched out on the shallower slopes in such a manner that all compacted fill is in contact with intact bedrock or competent soi Is. 4. All removals and excavating for canyon cleanouts, and processing in preparing -fill areas were inspected and approved by this firm's representative prior to placement of any fill. 5. Compaction tests were taken for each one to two feet of fill placed-. The maximum vertlca I depth of fi II placed is on the order of 1 d feet on Lot 50. 6. Lots 46-49, inclusive, 100-105, inclusive, and 127-129, inclusive, are in cut for the building pad area and contain no compacted fill. Random compaction tests performed at the finished cut grade indicate a suitable compact finished pad. 7. Based upon preliminary investigation and geologic inspection during grading, a 15-foot base width -compacted buttress fill was recommended and constructed f()r support of the proposed street cut slope at the side (southwest) of Lot 50. The locations and approximate limits of this buttress fill is shown on the encl~ed plan-; PACIFIC SOILS ENGINEEFUNG. INC. • • • • • October 19, 1976 Work Order 100236A Page Four 8. The cut portion of the transitional lot was overexcavated to a depth of 30-inches ~nd replaced as a compacted fi II to provide uniform bearing conditions. This was accomplished oli Lot 50 as indicated with a "C" on the enclosed plan. 9. Fill slopes were backrolled as they were brought to grade at approximate four- foot intervals. At the completion of fill placement, the slope was uniformly compacted by track-tolHng and ftnished by cutting and trimming .back to the compacted core. All slope dEmsification has been compfeted and the slopes are considered stable under normal conditions. 10. Materials encountered in cut and utilized for compacted fill ranged from non to • slightly expansive in nature. • • • • • A 'Iot-by-Iot eva luation of the soil conditions were 'conducted, with the subject . . residential lots being conside~ed to be very low in expansion potential, according to Table 29-C of the 1973 Uniform Building Code. Results of these' expansion tests are as follows: Expansion Potential Lot No.'s Soil. T~ee * Index** Ex~nsion*** (%Sand, Silt; 'Cloy) 46-49,.100-105, 127-129 F ,I 8 Very low 75 12 13 50, 134 F ,I,J 20 Low 72 .15 13 * ** *** Per tabulation (page 2) compaction test soil-types, upper three feet As determined in accordance with ASCI: -Expansion Potential Method Per Tobl¢ 29-C of the 1973 Uniform Building Code Design criteria for foundation and slabs-on-grade for the ,subject lots, 'are inc.luded in items 11 and 12 of this report. PACIFIC SOILS ENGII\IEERING. INC. • • • • • • • • • • October 19, 1976 Work Order 100236A Page Five 11. The following criteria should be used in foundation design for the residential lots. q) I b) The recommended bearing value for both the interior and exterior footings is 1500 Ibs ./sq .ft. having a minimum embedment depth of 12-inches and having a minimum width of 12-inches. A lateral bearing value of 300 Ibs ./sq .ft.· per foot of depth of a maximum of 1500 Ibs./sq.ft. may be utilized. A lateral s·liding coefficient of 0.40 may be used in design. The above values may be increased one-th~rd for short .duration loads such as seismic and wind loads. 12. Footing and slab-on-grade reinforcement criteria A .summary of foundotion requirements is presented on Plate A. a) Compacted fill lots 50 and 134 are considered to be non-expansive (very low) to slighfly expansive (low) in nature and therefore the following criteria should be used for design. -J-.- 1) Exterior foofings for two-story structures shall have a minimum embedment of l8-inches below grade. Interior footings for two-story structures and all footings for a single- story structure shall have a minimum embedment of 12-inches below grade •. Spread or isolated footings may be used. PACIFIC saiLS ENGINEERING. iNC.· .(2) .".-.,.".......~.--.. -._----------'------'_ ......... _--------------------_ ..................... _------------_ ... • • • • • • October 19, 1976 Work Order 100236A Page Six . I !P6e134 t All continuous footings~ b: reinforce.d with two No.4 bars, one placed in the bottom of the footing and one in the top. 2} All slabs-on-grade in living areaS shall be reinforced with a minimum of six-inch by six--inch, No'. 10 by No. 10 welded wire mesh £!:. equivalent positioned at the mid-height of the slabs; 12 by 12, W2.8 by W2.8 welded wire mesh is considered equiva.ent reinforcement. . 3) A minimum of lO-mil polyvinyl membrane is required under an slabs- on-grade in living areas. This membrane shall be convered by a minimum of one-inch of sand to aid in curing of the concrete. . 4) Slab subgrade for living areas and garage areas shall be moistened to at least optimum moisture, to a depth of '12-inches, prior to placi ng • concrete. 5) ~o special treatment of the garage areas is required, except that t.he • garage slab should have a positive separation from the stem wall '. b) Cut 10fS 46-49 inclusive, 100-105 in~lusive, and 127-129, inclusive, are --2Q£._ .. 1'1 ,' __ ~ __ ... • considered to be non-exeansiye..!very low) in nature and the following criteria -. . should be' used for design. • 1} , Exterior footings for tWo-story structures shall have a minimum embedment of l8-inches below grade. • Interior footings for two-story structures and all footings for a single PA~IFIC SOILS ENGU",EERING. INC. • • • • • October 19, 1976 Work Order 100236A Page Seven i 4b~<'1 I af) --I D'~­ './27",/2/1 story structure shall have a minimum embedment of 12-inches below grade. Spread or isolated footings may be used. Continuous footings needBe",reinforc;ed. __ • ...... M>:tm' 'JJ 4" b&A1C' 2} All slabs-on-grade in living areas shall be reinforced with a minimum ofsbc-inchbysix-inch, No.10by No. 10 welded wire mesh.5:[, eguivalent positioned at the mid-height of the slabs; 12 by 12, W2.8 by· W2.8 welded wire mesh is considered equivalent reinforcement. 3) A minimum of 10-mi~ polyvinyl membrane is required under all slabs-· on-grade. in living areas. This membrane shaH be covered by a minimum • of one-inch of sand to aid in curing of the concrete. 4) Slab subgrade for living areas and garage areas shall be moistened to • at least optimum moisture, to a depth of 12-inches, pri.or to placing • • • •• concrete. 5) No special treatment of the garage area is required, except that the, garage slab should have a ,positive separation from the stem wall. 13. Utility trench backfill should be ac~omplished in accordance with the prevaHing criteria of the City of Carlsbad. PACIFIC SOILS ENGINEERING; INC. '.' ..... @. • • • • • • • • • • • October 19, 1976 Work Order 100236A Page Eight RespectfuHy s~bmitted, PACIFIC SOILS ENGINEERING, INC. Reviewed by: &LQ.~ REX P. KETTER, Vice President . Dist: (10) Addressee AJJ:RPK/vll PACIFIC SOILS ENGINEERING ... "C. • • • • • • • • • • October 19 I 1976 Work Order 100236A Date of Test Test No. 10/14/76 585 II 587 10,,(15/76 588 II 589 II 590 II /591 II 592 10/16/76 600-ng .. 601 .. 602 II 603-ng II 604-ng .. 605 .. 607 II 608-ng TABLE I Test Elev. Moisture Location {feet~ !%~ Lot 50 165.0 12.4 Lot 100 163.0 11.7 Lot 134 179.0 12.4 Lot 134 181.9 14.3 Lot 50 170.0 ' 13.0 Lot 50 168.0 13.6 Lot 50 174.0 15.6 Lot 47' 180.7 14.3 Lot 40 176.0 11.7 Lot 50 179.9 10.4 Lot 127 176.6 12.4 Lot 104 174.1 13.0 ' Lot 100 165.0 13.6 Lot 100 166.8 16.3, Lot 102 170.6 14.9 ng Test in undisturbed natural ground Dry Density !., bs/ cu. ft .~ 107.5 111.5 110.4 107.0 109.5 111.0 111.4 110.1 107.6 109.0 109.4 111.0 108.5. 102.5 105.0 SC Indicates test by sand cone method; remaining t~ts by drive tube. Relative ComE!. % 92.0 95.0 94.0 91.0 94.0 94.0 95.0 94.0 92.0 93.0 . 94.0 95.0 93.0 9r.0 93.0 Areas not meeting minimum compaction requirements were re-worked and retested •. Only passing tests are shown in the above table. PACIFIC SCIILS ENGINEERING. INC. {. . ,. ~ . ..... Soil TlE!,e I SC I SC I ., I I I I SC I SC I SC I 5C I SC I SC F F .. (jf) .. • . October 19, 1976 Work Order lOO236-A • TABLE II Approxi mate Lot No. Depth(fe~t) • 46 Cut 47 Cut 48 Cut • 4·9 Cut 50 10 100 Cut • 101 Cut 102 Cut 103 Cut 104-Cut • 105 Cut 127 . Cut 128 Cut' • 129 Cut 134 4 • • • • PACIFIC SOILS ENGINEEf=iINGi INC. - I~ I=IACIFIC SOILS ENGINEERING. INC. SUMMARY OF FOUNDATION REQUIREMENTS 17921 SKY PARK CIRCLE (SUITE G) IRVINE, CALIF. 92714 • il' TELE~HONE: (714) 557-9450 TRACT NO. 72-34- .' .- FOOTING , FOOTING Depth Reinf. Slah ~/\Oist ,. -D-epth Reinf. Slab -Moist Lot Ext. Into Ext. Int. Re.inf. Rc-q 't. Lot Ext. Int. Ext. Int. Reinf. D,.::.qh. • f\.... I. 1 ,..-' ' X 'I 46 A A i X G J 47 A A I X xl G J I 48 A A I X X I G J 49 A A L X xJ G J , , --50 A A D .D G J • 100 A A rX )( 1 G J 101 A A J X X I G J 102 A A I X X J ~ I , 103 A A II X X I G J • 104 A A \ X X I ' G J, 105 A A 1 X xl G J 127 A A \ X XI G J 128 ,A A X xl G J 129 A A X xJ G J • 134-A A D D G J -- , I •• • LEGEND -.. -• 0_, -- A-12"; B -18"; C :"24" below lowest adjacent grade • D-One (1) No.4 rebar at top and one (1) at bottom E-Two (2) No.4 rebars at top and two (2) at bottom F-One (1) No. 5 rebar at top and one (l) at bottom , G'~ Six (6) inch by six (6) inch -No. 10 by No. 10 welded wire mesh, or equivalent. H-Six (6) inch by six (6) inch -No.6 by No.6 welded wire mesh, or equivalent. I -No.-reoors, -inches on center both ways. -• J-A moisture content of optimum moisture required to a depth of 12-inches below slab subgrade K-Presaturation of slab subgrade required to 105 percent of optimum moisture to a depth of 12-inch~ I ... below slab subgrade. , L .. Slab subgrade moisture to be verified by the soil engineer 1 prior to placement of visqueen and • reinforcement. X -NO SPECIAL REQUIREMENT . Note: 1) Exterior footings for 2.,.sfory structures must have a minimum embedment of l8-inches below grade. • 2) Exterior footings for 3-story structures must have a minimum embedinent of 24-inC~ . below gradei interiors, l8-inches below grade. -_ :/ . " -' . . -P[ATE . , . / -. ~ "' ---. --.-_.--. ~ -,. --._. , '