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Home My WebLink About; Western Recreation Bldg Ocean Point/Harbor Drive; As-Graded Geotechnical Report; 2002-03-12< SOIL & TESTING, INC. 11^ PHONE (619) 280-4321 TOLL FREE (877)215-4321 F A X (619) 280-4717 P.O. Box 600627 San Diego, CA 92160-0627 6280 Riverdale Street San Diego, CA 92120 ' www.scst.com AS-GRADED GEOTECHNICAL REPORT WESTERN RECREATION BUILDING OCEAN POINTE HARBOR DRIVE CARLSBAD, CALIFORNIA PREPARED FOR: REGIS HOMES, L.P. 18825 BARDEEN AVENUE IRVINE, CALIFORNIA 92612-1520 PREPARED BY: SOUTHERN CALIFORNIA SOIL & TESTING, INC. 6280 RIVERDALE STREET SAN DIEGO, CALIFORNIA 92120 Providing Professional Engineering Services Since 1959 TABLE OF CONTENTS SECTION PAGE 1. SUMMARY OF OBSERVATIONS AND TESTING 1 1.1 PROPOSED DEVELOPMENT 1 1.2 SITE PREPARATION ^ 1.2.1 Clearing and Grubbing ^ 1.2.2 Site Grading ^ 1.3 FIELD OBSERVATION AND TESTING 2 1.4 LABORATORY TESTS : ^ 2. CONCLUSIONS 3 3. FOUNDATION RECOMMENDATIONS 3 3.1 FOUNDATIONS ^ 3 3.1.1 General ^ 3.1.2 Reinforcement ^ 3.1.3 Foundation Excavation Observations 3.1.4 Expansion Characteristics ^ 3.1.5 Settlement Characteristics 3.2 CONCRETE SLABS-ON-GRADE 4 4. LIMITATIONS 4 ATTACHMENTS PLATES Plate 1 site Plan Plate 2 In-Place Density Test Results < SOIL ft TESTING, INC PHONE (619) 280-4321 TOLL FREE (877) 215-4321 F A X (619) 280-4717 P.O. Box 600627 San Diego, CA 92160-0627 6280 Riverdale Street San Diego, CA 92120 www.scst.com March 12, 2002 Regis Homes, L.P. 18825 Bardeen Avenue Irvine, California 92612-1520 SCS&T No. 9911144 Report No. 23 Subject; AS-GRADED GEOTECHNICAL REPORT WESTERN RECREATION BUILDING OCEAN POINTE HARBOR DRIVE CARLSBAD. CALIFORNIA Gentlemen: In accordance with your request, this report has been prepared to present the results of field observations and In-place density testing performed in conjunction with the grading operations for the subject site. Our services were performed between May 7, 2001 and January 29, 2002. To assist in determining the locations and elevations of our field density tests, we were provided with a grading plan prepared by Crosby Mead Benton and Associates, dated July 17,2001, which defines the general extent of site grading. 1. SUMMARY OF OBSERVATIONS AND TESTING 1.1 PROPOSED DEVELOPMENT The proposed recreation building will be located south of and adjacent to the western parking structure at the subject site. The structure will utilize masonry block and wood-frame construction, as well as shallow foundations and a concrete, on-grade floor slab. 1.2 SITE PREPARATION 1.2.1 Clearing and Grubbing Site preparation began with the removal of any existing vegetation and other unsuitable matter from the proposed development area. These materials were exported from the site. 1.2.2 Site Grading Prior to the subject grading operations, the area of the proposed recreation building was underlain by three different soil profiles. The area within approximately 15 feet of the parking Regis Horr^es. LP. March 12, 2002 Ocean Pointe, Westem Recreation Building SCS&TNo. 9911144-23 Page 2 structure retainlngwall was underlain by compacted retaining wall backfill soils placed in 2001. In-place density testing performed by SCS&T during the backfill operations indicated relative compaction of 90 percent or greater. These test results are presented on Plate No. 2. Site preparation performed within the wall backfill zone during the subject grading operations consisted of scarifying, moisture condifioning and compacting the upper 12 inches of the existing soils at pad grade. The approximate limits of the area underlain by compacted wall backfill are depicted on Plate No. 1 The southern portion of the proposed building pad was found to be underlain by nafive terrace deposits. These deposits typically consisted of medium dense silty sand. The terrace deposits were overexcavated to a depth approximately 5 feet below proposed pad grade and replaced as compacted fill. Pre-exisfing fill soils were encountered in the extreme southwestern corner of the proposed building pad. The fill soils became deeper toward the west, extending to a maximum depth of about 12 feet below proposed pad grade. The configuration of thefill soils suggests that they may have been associated with an access ramp graded during the construction ofthe adjacent sewer line in the early 1990s. Due to the inconsistent degree of compaction apparent in these soils, all pre-existing fill soils within the zone of influence of the proposed structure were removed to firm nafive ten-ace deposits and replaced with compacted fill. The approximate limits of ramp backfill soils removed, as well as the overall removal limits, are depicted on Plate No. 1. Following the removals, the soils generated by the removal operafions were placed as compacted fill. Fill was placed in 6- to 8-inch thick, moisture conditioned lifts and compacted until field density tests indicated a minimum of 90 percent of maximum dry density. Compaction was achieved by means of a backhoe-mounted compaction wheel and a vibratory roller. This process continued until proposed elevafions were reached. 1.3 FIELD OBSERVATION AND TESTING Field density tests were performed by a representative of SCS&T at the locafions shown on Plate No. 1. The tests were performed according to ASTM D 2922 (nuclear gauge) procedures. Test results are shown on Plate No. 2. The accuracy of the in-situ density test locations and elevafions is a funcfion of the accuracy of the survey control provided by others. Unless othenwise noted, their locafions and elevafions were determined by pacing and hand level methods and should be considered accurate only to the degree implied bythe method used. Observation and testing was performed on a periodic basis as the grading proceeded. As used herein, the term "observation" implies only that we observed the progress ofwork we were involved Regis Homes, LP. 'Ware/? 12, 2002 Ocean Pointe, Western Recreation Building SCS&TNo. 9911144-23 Page 3 with, and performed field density tests, which in conjuncfion with our observafions, were the basis for our opinion as to whether the work was performed in substanfial confonnance with the geotechnical recommendafions and the requirements of the applicable agencies. 1.4 LABORATORY TESTS Maximum dry density determinations were performed on representative samples of the soil used in the compacted fill according to ASTM D 1557, Procedure A. This procedure is used when the soil contains 20 percent or less by weight of material retained on the #4 sieve. This procedure specifies that a 4-inch diameter cylindrical mold of 1/30 cubic foot volume be used and that the soil tested be placed in five equal layers with each layer compacted by 25 blows ufilizing a 10-pound hammer with an 18-inch drop. This report summarizes work completed for the western recreation building only. Removal and recompaction operafions remain to be cornpleted forthe adjacent pool and pool deck area. 2. CONCLUSIONS Based upon our field observations and the in-place density test results, and to the best of our knowledge, the geotechnical engineering and engineering geology aspects of the grading were in compliance with our recommendafions, the City of Carlsbad Grading Ordinance, the Uniform Building Code, and currently accepted standards of practice. 3. FOUNDATION RECOMMENDATIONS 3.1 FOUNDATIONS 3.1.1 General Shallow foundafions may be ufilized for the support of the proposed improvements. The foofings should have a minimum depth 12 inches below adjacent finish pad grade. Minimum widths of 12 inches and 24 inches are recommended for continuous and isolated foofings, respecfively. A bearing capacity of 2000 psf may be assumed for all foofings. The bearing capacities may be increased by one-third when considering the total of all loads, including wind or seismic forces. 3.1.2 Reinforcement Both exterior and interior continuous foofings shouid be reinforced with at least two No. 4 bars posifioned near the bottom of the footing and at least two No. 4 bars positioned near the top of the foofing. This reinforcement is based on soil characterisfics and is not intended to be in lieu of reinforcement necessary to safisfy structural considerafions. Regis Homes, L.P. 'Wa'^^ ^2, 2002 Ocean Pointe, Wesfern Recreation Building SCS&TNo. 9911144-23 Page 4 3.1.3 Foundation Excavation Observations It is recommended that all foundafion excavations be approved by a representafive from this office prior to forming or placement of reinforcing steel. 3.1.4 Expansion Characteristics The prevailing foundation soils were classified as non-detrimentally expansive. The foundafion recommendations presented in this report reflect this condifion. 3.1.5 Settlement Characteristics The anticipated total and differenfial settlements for the proposed improvements will be within tolerable limits provided the recommendafions in this report are implemented. It should be recognized that minor cracks normally occur in concrete slabs and foundations due to shrinkage during curing or redistribufion of stresses and some cracks may be anficlpated. Such cracks are not necessarily an indicafion of excessive vertical movements. 3.2 CONCRETE SLABS-ON-GRADE The interior concrete floor slab for the proposed structure should have a thickness of at least four inches and be reinforced with at least No. 3 reinforcing bars placed at 18 inches on center each way. Slab reinforcement should be placed approximately at mid-height of the slab and extend at least 6 inches down into the foofings or walls. The slab should be underlain by a 4-inch blanket of clean, poorly graded, coarse sand or crushed rock. This blanket should consistof material with 100 percent passing the 1/2-inch screen and no more than 10 percent and 5 percent passing the #100 and #200 sieves, respecfively. Where moisture sensitive fioor coverings are planned, a 10-mil visqueen barrier should be placed over the sand layer. A1 -inch thick layer of additional sand should be placed over the visqueen to allow for proposed concrete curing. 4. LIMITATIONS This report covers only the services performed between May 7, 200t and January 29, 2002. Our opinions presented herein are based on our observations and the relafive compaction test results and are limited by the scope of the services that we agreed to perform. Our services were performed in accordance with the currently accepted standard of practice and in such a manner as to provide a reasonable measure of the compliance of the grading operations with the job requirements. No warranty, express or implied, is given or intended with respect to the services which we have performed, and neitherthe performance of those services nor the submittal ofthis report should be construed as relieving the contractor of his responsibility to conform with the job requirements. Regis Homes, LP. Ocean Pointe, Westem Recreation Building March 12. 2002 SCS&TNo. 9911144-23 Page 5 Our services were generally performed on an "on-call" basis. Therefore, the in-place density tests performed by our field representative can only be construed as representafive of the areas tested which are shown on the attached plates. Should you have any quesfions regarding the contents of this report, or If we may be of further assistance, please contact our office at your convenience. RNIA SOIL AND TESTING, INC. 1938 eologist Daniel B^8l^ f^^ScE.'36037 Vice President (3) (3) Addressee Jobsite JOB NAME: Ocean Pointe JOB NUMBER: 9911144 IN-PLACE DENSITY TESTS 1 TEST ELEVATION MOISTURE DRY DENSITY SOIL REL.COMP. NO. DATE LOCATION (feet,MSL) (percent) (P.c.f.) TYPE (percent) Gradina 125 1/8/02 West pool house 35.0 8.8 118.4 1 90.5 126 1/8/02 West pool house 37.0 8.7 114.7 5 91.4 127 1/9/02 West pool house 39.5 9.2 115.6 5 92.1 128 1/9/02 West pooi house 40.5 8.9 114.5 5 91.2 129 1/9/02 West pool house 41.5 6.4 110.3 5 87.9 130 1/9/02 RETEST OF 129 41.5 8.2 115.5 5 92.0 131 1/9/02 West pool house 41.5 8.2 113.9 5 90.8 132 1/11/02 West pool house 43.5 8.9 113.6 5 90.5 133 1/11/02 West pool house 45.5 10.1 116.2 5 92.6 134 1/11/02 West pool house 45.5 10.0 116.7 5 93.0 135 1/29/02 West pool house 46.5 9.3 114.7 5 91.4 136 1/29/02 West pool house 46.5 8.8 115.9 5 92.4 RETAINING WALL RWl 93 5/7/01 BIdg 6. SE Wall 40.0 9.2 111.4 6 92.8 RWl 94 5/7/01 BIdg 6, SE Middle Wall 40.0 9.4 115.5 6 96.3 RWl 95 5/7/01 BIdg 6. SE, Left of Wall 40.0 3.8 113.5 6 94.6 RW196 5/7/01 BIdg 6, South Wall, Middle 38.0 6.3 113.4 6 94.5 RWl 97 5/7/01 BIdg 6, South Wall, Middle 38.0 11.6 118.4 1 90.5 RW209 5/15/01 S Wall, West Parking Structure 40.0 9.8 115.2 5 91.8 RW210 5/15/01 8 Wall, West Parking Structure 42.0 11.2 115.8 5 92.3 RW212 5/16/01 South Wall, Parking Structure 40.0 9.2 117.5 5 93.6 RW213 5/16/01 West Wall, Parking Structure 42.0 9.4 115.6 5 92.1 RW214 5/16/01 West Wall, Parking Structure 44.0 10.8 116.6 5 92.9 RW222 5/24/01 SE Wall, West Structure 46.0 9.4 116.2 5 92.6 RW293 8/8/01 SW on west structure 45.0 7.8 119.9 5 95.5 MAXIMUM DENSITY AND OPTIMUM MOISTURE SUMMARY (ASTM D1557) Soil Maximum Optimum Type Soil DescriDtion Densitv. Dcf Moisture. % 1 Medium Brown, Silty Sand 130.9 8.4 5 Reddish-Brown, Silty Sand 125.5 8.5 6 Tan, Silty Sand 120.0 12.3 PLATE NO. 2