PRELIMINARY RESULTS OF THE GEOTECHNICAL INSTRUMENTATION PROGRAM FOR SUBSIDENCE MONITORING - UCG EXPERIMENT II

We have installed several types of geotechnical instrument systems at our Hoe Creek, Wyoming in situ coal gasification site to measure both surface and subsurface deformations resulting from gasification cavity creation. The subsurface instruments include two six position borehole extensometers in borings EX-1 and EX-2, two electrical shear strips in borings SS-1 and SS-2, a piezometer borehole PZ-1 containing four hydraulically isolated pore pressure transducers, and six boreholes completed so as to allow the use of a wire line inclinometer device.