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' Prese ad at the 9•h National Outdoor A=on Confmrense,Las Yeg=, ,Vevrd.May 1993 <br /> der of the drive shoe so the v <br /> the bottom of the inner barrel snug agasnsrt the shoal that soil moves <br /> ' easily into the sample liners as the dnve casino is advanced. Fnszally, after the three foot run is <br /> complete and the sample liners are full of soul, the inner barrel (containing the staiiless steel <br /> sample liners and soil) is retrieved by removing the internal rocas <br /> ' Whsle the internal rod method works weII at shallow depths,zecent improvements in the methods <br /> used to advance the Enviro-Core system have resulted in greater depths being attained This, in <br /> turn, requued a faster way to withdraw the inner barrel from the drive casing_ An inflatable <br /> packer, commonly used to seal boreholes during hydraulic testing, was modified to provide a <br /> means of connecting the =cr bawl to the drive casing (Figure 1) With this method, the inner <br /> barrel is coupled to the inflatable packer The packer/inner barrel assembly is quickly lowered to <br /> the bottom of the drive casing with a wireline. The shoulder in the drive shoe prevents the inner <br /> barrel from protruding beyond the bottom of the drive casing. The packer is then inflated with <br /> ' compressed nitrogen, rigidly coupling the inner barrel to the drive casing The inner barrel and <br /> dnve casing are then suuultaneously advanced three feet, filling the sample liners usside of the <br /> inner barrel with soil The packer Ls then deflated,and the inner barrellpacker assembly is <br /> ' quickly removed from the boring with a winch. The sampling sequence is shown to Figure 2. <br /> l} <br /> =I- LIzz <br /> I <br /> a o 0 0 0 <br /> SarnOe barrel Sample barrel oantamitg New sarnpla Semple barrel Waver sample9 Small-diameter <br /> and dMes mnil; sat rarrrmved ria barrel lowered to and drive ding are collected from piezometers of <br /> simultamousy wtra&ne Dnve csrng bomm of bonrtg advanced 3 more msda dn%fe Easing monrtorb ng points <br /> pushed left al sal to prevent ni,a vrtralrte feet wort a pensuft are mstalled pnor <br /> pounded Or s"tung and cross- <br /> punp or small- to wlhdrawnrg <br /> Abribed 3 feat cnnrarnMbon of$al diameter baler dire canna <br /> inra T44 samples <br /> Figure 2. sampiiug with the Ennro-Core® System <br /> t <br /> lie <br /> 4 <br /> TOTAL P 09 <br />