Effect of Wave Attenuation on Shear Wave Velocity Determination Using Bender Element Tests

Sensors

Xiaojun Zheng¹  Wenkang Luo¹  Yanbin Gao¹  Hao Wang² 

[1] Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China;Institute of Acoustics, Tongji University, Shanghai 200092, China;

关键词: bender elements;    signal interpretation;    wave attenuation;    shear wave;    time domain method;   

DOI  :  10.3390/s22031263

来源: DOAJ

【 摘 要 】

Wave attenuation is a widespread physical phenomenon in most acoustic tests, but there is a scarcity of quantitative investigations into the influence of wave attenuation on the determination of shear wave travel time in bender element tests. To ascertain this attenuation effect, a series of bender element tests were conducted on clay samples with different lengths under unconfined conditions. The experimental results suggest that the real first peak of the received signal attenuates gradually with the increase of the sample length and even becomes undistinguished when the sample length exceeds a limit. This phenomenon results in misinterpretation of the wave travel time using the time domain method. In this study, the shear wave travel time is misinterpreted when wave travel distance over approximately 80 mm, leading to underestimation of the V_S by 17% for the peak-to-peak approach and 10% for the arrival-to-arrival method. Therefore, besides the near field effect and boundary reflection, the wave attenuation effect turned out to be an important factor influencing the determination of V_S using the time domain method. Accordingly, it is advisable to predetermine the limit test distance for a specific testing system under conditions, particularly for long distance testing.

【 授权许可】

Unknown