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<br />. <br /> <br />~- <br /> <br />. <br /> <br />. <br /> <br />.. <br /> <br />. <br /> <br />EM 1110-2-1913 <br />31 Mar 78 <br /> <br /> <br />Table 2-3. Phase I Boring and Sampling Techniques <br /> <br />Teclmique <br /> <br />Remarks <br /> <br />L Disturbed sample borings <br /> <br />a . Split-spoon or standard I-a. Primarily for soil identification <br />penetration test but permits estimate of shear <br />strength of cl~s and crude estimate <br />of density of sands; see para- <br />graph 5-3d of EM 1110-2-1907 <br />(ref. A-3a( 8)) <br /> <br />Preferred for general exploration of <br />levee foundations; indicates need and <br />locations for undisturbed samples <br /> <br />b. Auger borings <br /> <br />I-b. Bag and jar samples can be ob- <br />tained for testing <br /> <br />2. Test pits <br /> <br />2. Use backhoes, dozers, and farm <br />tractors <br /> <br />3. Trenches <br /> <br />3. Occasionally useful in borrow areas <br />and levee foundations <br /> <br />3-in.-diameter samples are taken in cohesionless materials. EM 1110~2- <br />1907 (ref. A3-a(8)) gives detai~s of drilling and sampling techniques. <br /> <br />2-9. Borings. <br /> <br />a. Location and Spacing. The spacing of borings and test pits in <br />Phase 1 is based on examination of airphotos and geOlogical conditions <br />d~termined in the preliminary stage or known from prior experience in <br />the area, and by the nature of the project. Initial spacing of borings <br />usually varies from 200 to 1000 ft along the alignment, being closer <br />spaced in expected problem areas and wider spaced in nonproblem areas. <br />The spacing of borings should not be arbitrarily uniform but rather <br />should be based on available geOlogic information. Borings are normally <br />laid out along the levee centerline but can be staggered along the <br />alignment in order to cover more area and to provide so~e data on nearby <br />borrow materials. At least one boring should be located at every major <br />structure during Phase 1. In Phase 2, the locations of additional <br /> <br />2-5 <br />