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HomeMy WebLinkAboutCT 77-01; WOODBRIDGE UNIT 1; GRADING RECOMMENDATIONS; 1974-06-12-.,/1:', .. ___ .•• ~ SOIL AN.l> l\lA'.'I'~I.uAI. 'l]'~STI NO I.4AHOHATOUY OF" NORTH COUNTY, INC. o 12 June 1974.,/ Mr. John McKeand 2525 Jefferson Ave., Apt. K Carlsbad; California 92008 423 HALE AVE. -ESCONDIDO, CALIF". 92.025 ESCO'NDIDO --746-2333 C' 77-°1 Re: Job No. 74-68 ~ropos~d Apartment Complex ,2535 Jefferson Avenue Carlsbad, California Subject: 'Grading Recommendations Dea+ Mr. McKeand: Enclosed are our grading recommendations and ob~ervations on soil conditions as you requested for your above referenced pr~ject ' legally describad as a Portion of Sec.l, T12S, R5W, 5.8.8.& ~., City of Carlsbad, State of California. !t is understood the'site is intended to be developed for thre~'two and three story wood frame ap~rtment buildings. There will aiso be a one story building towards the front of the site. The building foundations ,will con~ist of concrete slab-on~grade with continuous concrete wall footings. The maximum cuts and fills will be in the order of 9 and 2 feet respec~ively. On 11 June 1974 I inspected the site and reviewed the Grading .Plan by E. 8rian Smith, Eng., Carlsbad. The subject tract is a' parcel 88 feet fronting Jefferson Street, and extending 495 feet towards the lagoon in the west. The site is gently sloping westerl~ and contains an existing house, shed, and some trees in the east central portion. Thes~ features are to be removed during gtading. , ," i . , , , , i I I o ,J • This laboratory did the fill control and foundation recommen- o dat~ons for the apartment di~ectlY to the south (Appleby -Job No. 71-41) and the .apartments~;ectlY to the north (McKoond-Job No. o 72-~7). Experience gained from these jobs and inspection of the site indicate no advers~ soil conditions are to·be expected on the' subject site. There are no obvious slides or' known slides in the area. Insp~ction of the footing trenches for th~ westerly most bui~ding on the McKeand job revealed the footings were founded in '~ weakly cemented ~andstone. These same conditions are anticipated fQr the westerly most building on the s~bject project. The grading . plan however indicates this building will be located further away from the bluff and hence in a more stable position. The root sjstem of large trees and any large buried objects encountered during grading should be removed and the voids back-o ,filled with compacted soil. Any clay found within two feet of final grade should be under- cut and repl~ced with compacted non expansive soil which is abun~ dant on site. Enclosed is a copy of our general grading specifitations. Please notify us'at least several days before gradi~g starts to discuss the grading operation and testing r'equired. Respectfully submitted" SOIL AND MATERIAL TESTING LABORATORY OF NORTH COUNTY, INC. Claude B. Parker Registered Civil Engineer #18,987 Certified Engineering Geologist #922 o Distribution: 4.jAddressee mb SOIL AND MATERIAL TESTING LABORATORY a" NaRTH CaUNTY, INC • ., .'.,.~ ..... _ ...... I-'''"'''-''_ ...... , . , " 1 I 1 t SOIL AND MATERIAL TES'l'ING LABORATORY OF" NORTH;'. COUNTY, INC. :J 423 HALE AVE. -ESCONDIDO, CAL.IF". 92025 ESCONDIDO -746·2333 SPECIFICATIONS FOR CONs1RUCTION OF CONTROLLED FILLS GENERAL DESCRIPTION: The construction of controlled fills shall consist of adequate preliminary soil inv~stigations, and clearing, r~moval of existing structures and foundations, preparation of land to be filled, excavation of earth and rock from cut area, compacti~n and control of the fill, and all oth~r work necessary to complete the grading of the filled areas to conform with the lines, grades,' and slopes as' ~hown on the 'C? c c e pte d pIa n s • " l!};, ~;::- CLEARING AND PREPARATION OF AREAS TO BE FILLED: , ' , ; (a) 0~~1 fill co~tr~l ~rojects ~hall have a prelimtparYr so~l investiq?tion ~r. a :;w~s~al ex~m~na,t:·jl;~, depend~n~ upon the nature of the Job, by a qual-c ~ f ~ ed~l so~ I eng~neer pr ~or to grad~ng. (b)' All timber, trees, brush, vegetation, and othsr rubbish shall be re- moved, piled and burned, or otherwise disposed of to leave the prepared areas with a finished appearance free from unsightly debris. " (c) Any soft, swampy or otherwise un~uitable areas, shall be corrected by drainage or removal of compressible material, or both, to the depths in- <=Jicated on the plans or as directed by the soil engineer. (d) The natural ground which is determined to be satisfactory for the support of the filled ground ~hall then be plowed o~ scarified toa depth of at least six inches (6") or deeper as specified by the soil engineer, and until the surface is free from ruts, hummocks, or other uneven fea- tureswhich would tend to prevent uniform compaction by the eqUipment to be used. '(e) NO fill shall be placed until the prepared native grouhd has been approved by the soil engineer. (f) UJhere fills are made on hillsides with slopes greater than 5 (hori- zontal) to 1 (vertical), horizontal benches shall be cut into firm un- disturbed natural ground to provide lateral and verti~~l stab~lity. The initial bench at the toe of the fill shall be at least 10 feet in width on firm undisturbed natural ground at the elevation of the toe stake. The soil engineer shall 'determine the width and frequency of all suc- ceeding ~enches which will vary with the soil cOndition~ and th~ steep- ness of slope. (g) After the natural ground has be~n prepared, it shall be brought to the prop~r moisture content and, ccimpacted to not less thah 90% of max~ imum density, A.S.T.M. D1557-64T~ ( , , '-" . (h) Expansive soils may requ1re special compaction specifications as directed in the preliminary soil investigation by the soil engineer. (:', ~-\i) The cut portions of building pads in which rock-like material exists may require excavation and recompaction for density compatibility with I the fill as directed by the soil engineer. MATERIALS: The fill soils shall consist of select materials gr~ded so that at least 40 percent of the material passes the No., 4 sieve. The material may be obtained from the excavation, a boxrow pit, or by mixinQ soils from one or more sources. The material used shall be free from vegetable matter, and other deleterious substances, and shall not contain rocks or lumps greater than 6 inches in diamet~r. If excessive vegetation, rocks, or soils with unacceptable physical characteristics are encountered~ these materials shall be 'disposed of in waste areas designated on·the plans or as directed by the qoil engineer. If soils are encount~red during ~he gradiAg operation which were not reported in the preliminary soil inv~st- 'igation, further testing will be required to ascertain their engineering prope~ties. Any special treatment reciommended in the preliminarY or sub-. sequent soil reports not covered herein shall become aM addendum to these specifications. No material of a perishable, spongy, or otherwise unstable nature shall be used in the fills. PLACING, SPREADING AND COMPACTING FILL MATERIAL: (a) The selected fill material shall be placed in layers which shall not exceed six inches (6") when compacted. Each layer shall be sptead Cwenly and shall be thoroughly blade~mixed during the s,preading to insure uniformity of material and moisture in each layer. (b) fied tent ough When the moisture content of the fill material is below that speci- by the soil engineer, water shall be added until the moisture con- is near optimum as determined by the soil engineer to aasute thor- bonding during the compacting process. (c) When the moisture content of the fill material is above that speci- fied by the soil engineer, the fill mat~rial shall be aerated by blading and scarifying, or other satisfactory methods until the moisture tohtent is near optimum as determined by the soils engineer. (d) After eaoh layer has been plaoed, mi~ed and spread evenly, it shall be thoroughly compacted to not less than the specified maximum density in accordance with A.S.T.M. D1557-64T. Com~action shall be by meanaof tamping or sheepsfoot rollers, multiplB-wheel pneumatic-tired rol;ers, or other types of rollers. Rollers shall be of such 'design that they will be able to co~pact the fill to the specified density. Rolling af each layer shall be continuous over its entire area and the roller shall make ~ufficiant passes to obtain the desired density. The,entite atea to be fi~led shall be compacted to the specified ~,nsity., o SOIL AND MATERIAL TESTING LA.BORA.TORY 01" NORTH COUNTY, INC. -2- . i'" , -(e) Fill slopes shall be compacted by means of sheepsfoot rollers or _ other ~uitable equipment. Compacting operations shall be co~tinued Dntil c;the slope~ are stable but not too,dense for planting and un~il th~re is -no apprec~able amount of loose so~l on the slopes. Compact~ng of the slopes shall be accomplished by backrolling the slopes in increments o~ 3 to 5 feet in elevation gain or by other methods producing satisfactory results. (f) Field d~nsity tests shall be made by the soil engineer for approx- imately each foot in elevation gain after compaction, but not to exceed two feet in vertical height between tests. The location of the tests in plan shall be spaced to give the best possible coverage and shall be taken no farther than 100 feet apart. Tests shall be takeh on corner and terrace lots for each two feet in elevation gain. The soil ingineer may take additional tests as considered necessary to check on t~e uniform- ity of compaction. Where sheepsfoot rollers are used, ths tests shall bet a ken i nth e com pac ted mat e ria 1 below the dis t u r bed sur f a c·e • No additional layers of fill shall be spread until the field density tests indicate that the specified density has been obtained •. (g) The fill operation shall be continued in six inch (6") compacted layers, as specified above, until the fill has been brought to the fin-. ished slopes ~nd grades as ~hown tin the accepted plans. SUPERVISION: Supervision by the soil engineer shall be made during the filling and compacting operations so that he can certify that the fill was made in accordance with accepted specifications. C.r he s p e c i f i cat ion san d s.o i 1 t est i n g 0 f sub g-r ad e , sub bas e, and bas e materials for roads, or other public property shall be dbne in accordance with specifications of the governing agency. o SEASONAL LIMITS: No fill material shall be placed, spread, or -rolled during unfavorable weather conditions. When the work is interrupted by heavy rain, grading shall not be resumed until -field tests by the sdil engineer indicate that the·moisture content and density of the fill are as previously specified. In the event that, in the opinion of ~he engineer, _ soils unsatisfactory as foundation material are enco-uhtered; they shall not be incorporated in the grading and disposition will b~ made at the engineer's discretion. . . - SOIL AND MATERIAL TESTING LABORATORY OF' NORTH COUNTY; INC. -3- , -: , c orL IDENTIFYING CRITERIA I. COARSE GRAINED ( More -than 50% #200 si eve) GRAVELS· (More than 50% #4 sieve b~t smaller than 3 indhes) No'n Plastic SANDS (More than 50% smaller ·than #4 sieve) Non Plastic FINE GRAINED (More than 50% smaller than.#200 sieve) Liquid Limit less than 50 Liquid Limit greater than 50 III. HIGHLY ORGANIC SOILS , o GROUP SYMBOL Gill GP GM GC Sill SP SM SC ML CL OL MH CH OH PT GRAVEL, well graded gravel- sand mixture, little or no . fines. GRAVEL, poorly graded gravel~ sand mixture, little. or no fines. . GRAVEL, SILTY, poorly graded gravel-sand-silt mixtures o G R A VEL, C LAY E Y, P 0.0 r 1 y g r a d e d gravel-sand-clay mixture. SAND, well graded, gravelly sands, little or no fines. SAND, poorly graded, gravelly sands, little or no fines. SAND, SILTY, poorly graded sand-silt mixtures, SAND~ CLAVEY, pODrly ~raded sand-clay mixtures. SILT, INORGANIC, silt and·fine sand, sandy silt or clayey- silt-sand mixtures with slight plastici ty. CLAY, INORGANIC, clays of low tc medium plasticity, gravelly . clays, sandy clays, silty clays: lean clays. SILT, ORGANIC, silts and or- ganic silt-clays of low plasticity. I SILT,. INORGANIC, silts micaceou or dictomac~ous fine sandy or silty soils, elastic silts. CLAV, INORGANIC, clays of med- ium to high plasticity, fat clays. . . CLAV, ORGANIC, clays of medium' to high plasticity. PEAT, other highly organic swamp soils. SOIL AND MATERIAL TESTING LABORATORY OF' NORTH COUNTY, INC.