11731 AIRPORT RD Geotech Report 2018-01-02 MF Import

08/18/2005 15:27 4257478561 GEOTECH PAGE 03 Lucia Devebpment llC JN 05233 August 18,2005 Pege 2 SUBSURFACE The subsurface conditions were explored by excavating eleven test pits and drilling two borings at the app►oximate locations shown on the SRe Exploration Plan, Plate 2. Our exploration program was 6ased on the proposed construdion, anticipated subsurface eonditiona and those encourrtered during expioration, and the scope of work autlined in our proposal. The test pits were excavated on June 2D, 2W5 with a rubber-tired baCkhoe. A geotechnical engineer from our statf observed the excavation process, logged the test pits, and obtained representative samples of the soil encountered. "GI'ab" samples of seleeted subsurface soil were collected from the bacichoe bucket. The Test Pit Logs are attached to this report as Plates 3 through 8. The bodngs were drilled on July 21, 2005, using a track-mounted, hollow-stem auger drill. Samples were taken at 5-toot intervais with a standard penetration sampler. This split-spoon sampler, which has a 2-inch outside diameter, is driven into the soil with a 140-pound hammer falGng 30 inches. The number of blows required to advanee the sampler a giver distance is an indication of the soil density or consistency. A geotechnieal engineer from our staff observed the driliing process, logged the test barings, and obtained representative sampies of the soii enoountered. 7he Test Boring Logs are attached as Plates 9 and 10. Soil Condltlons The test pits generally encountered uncompacted fiii and soft silts wfth organic layers to the manimum explored depth of the test pits. N,,mernus o6structlons, such as househoid garbage and construction debris were encountered in the test pits. The test pits were explored to depths of 3.5 to 13 feet below existin0 grede, All test pits were encavated urrtil either the backhce could not penetrate through the debris, or the ma�amum reach of the baekhoe was attained. Moderete to severe caving was observed in most of the test pits in the�oose fill soils. Boring 1, drilled at the narthem end of the proposed restaurant footprint, encountered an upper soil unit of approximately 14 feet of soft silt and peat with organics. Underfying the loose sods was dense sand and siRy sand that became very dense at approximately 25 feet below existing grade. The very dense soils extended to the maximum explored depth of the boring. 8oring 2, driiled near the westem end of the proposed retail buildi�g footpriM, encountered approximately 24 feet of soft siR and loose silty sand underlain by dense to very dense, sandy silt, that extended to the ma�amum explored depth of the boring. Both borings were each explored to a depth of 31.5 feet below existing grade. Groundwater Condrtions Groundwater seepage was observed at a depth of 3 to 13 feet in the test pits and horings. Caving was observed in a majority of the test pits. The test pits and borings were left open for only a short time period. Therefore, the seepage levels on the logs represent the location of transient water seepage and may not indicate the static groundwater level. Groundwater levels encountered during drilling ean be deceptive, because seepage into the horing can be blociced or slowed by the auger Rseif. It should be noted that groundwater levels vary seasonally with rainfall and other tadors, The test pits and borings were per(ormed during an extended period of dry weather in July. GEOIECH CONSULTANTS.INC.