1011 39TH ST 2016-01-01 MF Import

APPENDIX A FIELD EXPLORATION E•10138 Our subsurfar.e exploration was perforr-ied on July 5, 199�. Subsurface cor,ditions at the site were exp��red by drill�ng four borings to a maximum depth of twenty-one and one half (21 .5) teet below existing grade. The borings were drilled by Geologic Drill, subcontracted to ECI, using an Acker Soil Meclianic clrill ric�. Approximate boring locations were determined by taping and pacing from buildir.� corners a�> depicted on a design plan dated Maroh 10, 1983. ApproxiiTiate boring el��vations were estimated based on topocraphic data shown on the site plan. The topoyraphic map was prepared prior to construction of the existing single-family resid�nce and tlie railroad tie retaining wall. As such, the existing e'evations were estimated. The locatio,�s and eleva- tions o( the borings should be considered accurate only to the degree ircplied by the method used. These approximate locations are shown on the Boring Location Plan, Plate 2. Ttie field exploration was continuously monitored by a geologist from our firm wlio classified the soils encountered, maintained a log o( each boring, obtained representaiive samples, measured groundwater levels, and observed pertinent site features. The samples were visually classified in accordance �riith the Unified Soil Classi(ication System ��resen!Ed on Plate A1 , Legend. Representative soil samples were collected and returned to our laboratory for furtlier examination and testin,. Logs oi the borings are presented on Plates A2 thrcugh A8. The (;nal loc�s represent our interpretations of the field lo�s and the results of the laboratory examination 3nd tests of field samples. The stratification lines on the logs represent the approximatc boundaries between soil types. In actuality, the transitions may be mora gradual. The borings were drilled �.ising hollow stem auger equipment. In each boring, Standard Penetration Tests (SPT) were perfomied at selected intervals in general accordance with ASTM Test Desi�nation D-158G. The split spoon samples were driven with a one hundred forty (140} pound hammer freely falling thirty (30) inches. The number of ble�vs required to drive the Iast twelve 112) inches of penetration are called tLe "N-value". This value helps to characterize the site soils and is used in our engineering analyses. These results are recorded on the borinc logs at the appropriate sample depths. �:� . , _., ,�:�...�. . . o,....