Tomographic DST Algorithm for Stone Column Site Imaging and Characterization-PPT Presentation

PPT Presentation

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The presentation introduces a tomographic algorithm for applying downhole seismic testing (DST) to sites containing stone columns, where the columns may complicate seismic ray paths and interpretation. Typical stone columns are 0.6–1.1 m in diameter, with center-to-center spacing of 1.5–2.5 m.<br /><br />The proposed method is intended to estimate soil interval velocities in these conditions. In a test-bed simulation, its estimated velocities were generally close to the known values, with percent differences mostly below 5%. The comparison method (SRA) produced highly variable estimates in several intervals, including extreme outliers.<br /><br />The authors conclude that the new algorithm makes DST applicable in areas with stone columns. It has so far been tested only through simulations; field testing is planned, with results to be reported separately.

Keywords

tomographic algorithm

downhole seismic testing

stone columns

soil interval velocities

ray path complications

seismic interpretation

test-bed simulation

percent differences

SRA comparison method

field testing