The Influence of the Expansive Grout on Theoretical Bandwidth for the Measurement of Strain Waves by Borehole Tensor Strainmeters

摘要: The scattering model of incident seismic waves by an empty borehole has been presented to investigate the theoretical frequency response and corresponding bandwidth tensor strainmeters. Inner-diameter changes stainless steel instrument casing are measured horizontal extensometers (gauges), after strainmeter is installed at a certain depth boned expansive grout with surrounding rock. There is, however, no answer for difference between this case case. In paper, elastic two-ring introduced influence on measurement strain calculation wave fields in rock two rings function expansion gives inner-diameter casing. Several cases show that mechanical parameters have great responses strainmeters different gauge combinations, but little bandwidth, which means high-frequency promises quantitative measurability acoustical range