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Home My WebLink AboutCT 72-15; Park Manor No. 1; Soils Report; 1967-03-30SCl)BL BES-U-UN6 I-A83BDDA+dlRY OF NORTH COUNTY INC. 423 HALE AVE. . ESCONDIDO, CALF. 92025 ESCONDIDO-746.2333 OCEANSIDE-722.2125 March 30, 1967 Mr. Donald A. Briggs, Jr. 4115 Sunny Hill Drive Carlsbad, California Re: Job No. 67-5 Preliminary Soils Investigation Park Manor No. 1 Carlsbad, California Dear Mr. Briggs: i, In accordance with your request, we have completed the soils investigation for the subject project. This report describes the results of the investiga- tion and includes the recommendations for the foundation design of the pro- posed structure. Respectfully submitted, SOIL TESTING LABORATORY ~;~;‘~N~+ E. Brian Smith RCE 13, 817 EBS:mab -. PRELIMINARY SOILS INVESTIGATION PARK MANOR NO. 1 CARLSBAD, CALIFORNIA FOR DONALD A. BRIGGS, JR. BY SOIL TESTING LABORATORY OF NORTH COUNTY, INC. March 30, 1967 67-5 TABLE OF CONTENTS PAGE I. General Information II. Purpose of Investigation III. Field Investigation A. Surface Conditions B. Test Pits C. Soils Encountered IV. Laboratory Tests V. Conclusions VI. Recommendations APPEND= Location of Test Borings Logs of Borings Consolidation Curves Specifications for Construction of Controlled Fills. 1 1 1 1 1 2 2 3: 3 PLATE 1 2&3 4 ,, . SCl>BBL TESTIN LA OiQATOIRY 423 HALE AVE. _ ESCONDIDO, CALIF. 92025 ESCONDIDO-746.2333 PRELIMINARY SOILS INVESTIGATION OCEANSIDE-722.2125 PARK MANOR NO. 1 CARLSBAD, CALIFORNIA I. GENERAL INFORMATION: A preliminary soils investigation has been completed on the proposed Park Manor No. 1 subdivision tract in the City of Carlsbad, California. It is understood the property is to be developed into a residential sub- division. Future drainage of the residential Iots xvi11 be directed into the streets and storm drains. II. PURPOSE OF INVESTIGATION: The purpose of the investigation was to determine the folIowing: =. 1 b. 1 c. 1 d. 1 e. ) f. ) !3 ) The existing soil conditions The condition of areas to receive fill The characteristics of proposed fill material The presence and effect of any expansive soil Allowable soil bearing pressures Estimated settlements Any construction problems that can be anticipated III. FIELD INVESTIGATION: A. Surface Conditions: The site may be described as gently sloping in a downward direction toward the east and west. At the present time flowers are growing on the property. B. Test Pits: Three test holes, located as shown on Plate 1, were dug with a back- hoe. Field logs of the soils encountered in the test holes were re- corded at the time the holes were dug. Field density tests were made at various depths in each test hole. Un- disturbed samples of the typical soils were obtained with a sampling tube which was driven into the soils ahead of the exploration. Loose bag samples of the typical soil types were also obtained. The Logs of Borings presented on Plates 2 and 3 were prepared on the basis of the field logs, examination of the samples and the laboratory test results. The position of each sample obtained with- in the test holes is shown on the Logs of Borings. Ground water was not encountered. C. Soils Encountered: The soils profile, as revealed by the test holes, consist of 0. 5 feet of loose topsoil. Mediuxn firm to firm, fine to medium sand was found underlying the topsoi1 in test holes 1 and 2. A fine uniform sand was found underlying the topsoil in test hole 3. No potentially expansive soil was found. IV. LABORATORY TESTS: Laboratory tests were performed on a11 field density test samples to determine the dry density and moisture content. The results of these tests are presented on Plates 2 and 3 inclusive. Consolidation tests were performed on representative samples in order to determine the load-settlement characteristics of the soils. The re- sults of the consolidation tests are presented on Plate 4. Mechanical analysis tests were performed on the major soil types in accordance with A. S. T. M. Designation D 422-6lT. The results of these tests are as foIIows: U. S. Sieve Size No. 314” No. 4 No. 10 No. 40 No. 100 No. 200 Soil Description PERCENT FINER BY WEIGHT Test Hole 2 Bag 1 (4.0’ - 4.5’ ) 100. 0 99.4 90.2 63. 7 37. 8 17.3 Fine to medium sand Test Hole 3 Bag 2 (3. 5’ - 4.0’ ) 100.0 100.0 100. 0 81. 0 45. 5 22. 8 Fine uniform sand Compaction tests were performed on representative samples of the sdls to be excavated and used as fill in order to establish compaction criteria. The soils were tested according to the A. S. T.M. Designation 1557-58T method which uses 25 blows of a 10 pound hammer dropping 18 inches on each of 5 layers in a 4 inch diameter l/30 cubic foot mold. SOIL TESTING IABC)RATORY OF ““R,Trtj COUNTY INC. A summary of the results of the tests are presented as follows: Test Hole Bag Depth in Soil Max. Dry Optimum NO. Sample Feet Description Density Moisture Ibl CU. ft. qo Dry Wt. 2 1 4. O-4.5 Brown fine to 130.5 9.5 Medium Sand 3 2 3. 5-4. 0 Brown fine 124.0 10.5 Uniform sand Shear tests were performed on selected samples in order to determine the minimum angle of internal friction and apparent cohesion of the representative soil types. The test results and the calculated angles of internal friction and apparent cohesion6 are presented below: Normal Shearing Angle of Apparent Load Strength Internal Friction Cohesion Kipslsq. ft. Kips/sq. ft. Degrees Ib/sq.ft. Boring 3 0. 5 0. 70 19. 0 550 Depth 4. O’-5. 0’ 1. 0 I. 12 2. 0 1. 23 V. CONCLUSIONS: Clearing of the existing vegetation on the site will be required. The undisturbed natural soils below the existing topsoil are suitabIe for the support of fil1 and/or residential dweIIings. No potentially expansive soil was found during the investigation. AI1 the existing soils that are free of vegetation may be satisfactorily used as fill. Calculations, based on the results of shear tests performed on undisturbed samples of the natural soil indicate an allowable bearing value d 1500 pounds per square foot may be used for l-foot wide continuous footings founded at least l-foot in undisturbed natural ground. It is estimated that the settlement of a continuous footing loaded to 1500 pounds per square foot will be less than l/4 inch. VI. RECOMMENDATIONS: All vegetation shall be cleared from the site. The loose topsoil, if not removed during the process of grading and used as fill, shall be scarified, brought to the proper moisture content, and SOIL TESTING LADORATGRY OF “““(Tq COUNTY INC. .‘,,, compacted to at least 90 percent of the maximum dry density. Recommendations for the placing of fill ground are presented in the “Specifications for Construction of Controlled Fills” contained in the Appendix to this report. If any soil types are encountered during the grading of the site that were not tested in the process of this investigation, additional Iabor- atory tests shall be conducted in order to determine their physical characteristics. Supplemental reports and recommendations will automatically become a part of the specifications. Respectfully submitted, SOIL TESTING LABORATORY OF NORTH COUNTY, INC. 2ciL& .A+&- E. Brian Smith RCE 13, 817 EBS:ct SGIL TESTING IADQRATORY OF NORTH COUNT” INC. (?) 0 TES 7= LOCA T/ON _- SRIL TESTING IADRRATRRY OF NORTH COUNTY INC. LOG OF BORING z . .$ b . .z 2 0 BORING NO. I c ‘gg 2 ; c. ?Z g; -& ./_I s=ro 2: pa” < ‘2 $g za Q 4 $0 Elevation 173+ * G $gQd 22 p;u ?‘-r.h*. Brown. loose silt IToDsoil) - _.._ ., 2 - t :, .’ “__ . . - ; .; ~ 4 -,;Q;. Brown, fine to medium sand Firm. Moist. SW 9.6 1lO.C 84.3 ; -.*;$j SW 8.7 115.3 88.4 .-. .: 3 -,;A& SW 9.4 112.3 86.2 0 ; 4 .‘; SW 7. 8 109. 3 83. 7 BORING NO. .2 0 Elevation 166 2 * .-) \‘C L(. Rrown, loose silt (ToDsoil) _. -. ,..-:. ,.. .- 2 -..: + - _o: Brown, fine to medium sand SW 8. 9 110. 8 84. 9 4 -..“,Q: Firm. Moist. 6 -‘::;Gj;: SW 9.6 108. 7 83. 3 I’- _. ‘,: 1.: 71 _ . . *:. I 8 : I .-I :. ,o -&;, SW 8. 5 110.8 84. 9 * The approximate elevations were determined by interpdation between the contour lines shown on the Grading Plan prepared O- by Roy L. Klema, Engineers, Inc. dated March 8, 1967. Indicates Field Density Test 0 - Indicates Loose, Representative Bag Sample JOB NO. PLATE NO. 67-5 PARK MANOR NO. 1 2 SQIL TESTING LbDORATC)RY OF NORTH COUNTY INC. LOG OF BORING x g 2 a, s .z & .i BORING NO. c: “a. F$/ 22 3 0 . .;:‘d: aI9 “h Eiz .s (D 22 a< ‘Z a%? n 2 0 d .3 (D i!E Elevation 164’* lJY t; k ‘2 c;: - 0 :.~;\:..~~ :i ZQ - c?G Brown. loose silt - 3.:: j..;, . 2 2@\ SP 9. 9 103. 7 83. 7 Brown fine uniform sand. Firm. Moist. SP 9. 2 113. 4 9 1. 8 SP 8. 5 108.6 87. 5 q - Indicates undisturbed samples JOB NO. PLATE NO. 67-5 PARK MANOR NO. 1 3 Sc)IL TESTING LABRRATQRY OF NORTH COUNTY INC. CONSOLIDATION CURVES 0 1 2 Job No. 67-5 PARK MANOR NO. 1 Plate No. 4 SOIL TESTING LABORATc)RY OF NORTH COUNTY INC. ~.--‘A. --.- Specifications for Construction of Controlled Fills CONSTRUCTION OF CONTROLLED FILLS GENERAL DESCRIPTION: This item shall consist of all clearing and grubbing, removal of existing structures and foundations, preparation of land to be filled, filling of the land, spreading, compaction and control of the fill, and all other subsidiary work necessary to complete the grading of the filled areas to con- form with the lines, grades and slopes as shown on the accepted plans. CLEARING, GRUBBING AND PREPARING AREAS TO BE FILLED. (a) All timber, logs, trees, brush and other rubbish shall be removed, piled and burned or otherwise disposed of so as to leave the areas that have been disturbed with a neat and finished appearance free from unsightly debris. (b) All vegetable matter shall be removed from the surface upon which the fill is to be placed, and the surface shall then be scarified to a depth of at least six inches (610) and until the surface is free from ruts, hummocks or other uneven features which would tend to prevent uniform compaction by the equipment to be used. (c) Fills over three feet (3’) high shall have steps cut in the original ground at two foot vertical intervals on the slope. The steps shall be eighteen inches (18”) wide, more or less, and may be constructed by dozing or blading. The general direction of the bench shall run parallel with the contours and the maximum slope shall be three horizontal units to one vertical unit. (d) After the foundation for the fill has been cleared or scarified, it shall be disced or bladed until it is uniform and free from large clods brought to the proper moisture content and compacted to not less than 90% of maximum density in accordance with A.S.T.M. D1557-58T. No fill shall be placed until the soils engineer has given written clearance that the foundation is acceptable for receiving fill. MATERIALS: Material for the fill shall be free from vegetable matter and other deleterious substances, and shall not contain rocks or lumps of greater dimensions than six inches (6”). No pockets of rocks shall be allowed, PLACING, SPREADING A ND COMPACTING FILL MATERIAL. (a) The selected fill m%terill shill be placed in layers which, when compactEd, shall not exceed six inches (6”). Each layer shall be spread evenly and shall be thoroughly blade mixed during the spreading to insure uniformity of material in each layer. Fo’rm #78 -l- I ,,’ :, .I,~ : : (1s) When the moisture content of the fill materials is low water shall be added to bring the fill within the specified density range. (1:‘) When the moisture content of the material is above that specified by the densi,ty range, the fill material shall be serated by blading or other satisfactory methods until the moisture content is within the density range. (d) After each layer has been placed, mixed and spread evenly, it shall be thoroughly compacted to not less than the specified maximum density in accor- dance with A. S. T. M. D1557-58T. Compaction shall be by means of tamping or sheepsfoot rollers, multiple-wheel pneumatic-tired rollers or other types of rollers. Rollers shall be of such design that they will be able to compact the fill to the specified moisture content. Roliing of each layer shall be contin- uous over its entire area and the roller shall make sufficient trips to insure that the desired density has been obtained. (e) Fill shall be compacted one foot beyond the finish grade line and cut back to grade line by removing fluff and undercompacted fill. ,,.r- ~. (f) Field density tests shall be made by the soils engineer at intervals not exceeding two feet of fill height provi,ded all layers are tested. Where sheeps- foot. rollers are used, the soil may be disturbed to a depth of several inches. Density readings shall be taken in the compacted material below the disturbed surface. When these readings indicate t.hat the density of any layer of fill or portion thereof is below the required density, that particular layer or portion shal.1 be reworked u,ntil the required 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 finished slopes and grades ‘as shown on the accepted plans. SUPERVISION: Supervision by the soils engineer shall be made during the fill and contracting operations so that he can certify that the fill was made in accor- dance with accepted specifications. SEASONAL LIMITS: No fill material shall be placed, spread or rolled while it is frozen or thawing or during unfavorable weather conditions. When the work is interrupted by h,eavy rain, fill operations shall not be resumed until field tests by the soils engineer indicate that the moisture content and density of the fill are as previously specified. In the event that, in the opinion of the engineer, the soils unsatisfactory for grading purposes are encountered, they shall not be incorporated in the grading and disposition will be made at the engineer’s discretion. Form #78 -2-