Laserfiche WebLink
' n <br /> ESE STANDARD OPERATIONS PROCEDURES <br /> Drilling Procedures - Hollow Stem Auger Rigs <br /> The borings are drilled with a minimum outside diameter 7 1/4 inch Mallow-stem auger. <br /> The auger flights are steam cleaned prior to their arrival on site and after each use. <br /> During drilling a retractable plug prevents soil from entering the central shaft of the auger <br /> flight. Undisturbed soil samples shall be recovered from the borings without introducing <br /> liquid into the borings. <br /> : e <br /> Soil Sampling Procedures <br /> Relatively undisturbed soil samples shall be collected from the borings for chemical analysis <br /> and visual description. When the target depth is reached a Modified California Sampler, <br /> consisting of an outer sampler barrel lined with two 6-inch long rings (OD 2.5 inch)placed <br /> end to end, is used to collect the soil samples.The Modified California Sampler and brass <br /> rings are cleaned prior to each assembly. The equipment is washed with tri-sodium <br /> N phosphate solution, rinsed in tap water and allowed to air dry.The sampler is attacbed to <br /> - red through the hallow-stem auger, and driven 12 inches into <br /> the drive hammer, lowe <br /> undisturbed sail ahead of the auger. The sampler is then retrieved and the rings removed. <br /> e <br />