基于电阻率层析扫描的水下抛石体内部空洞探测

Internal cavity detection of underwater riprap based on resistivity tomography

为提高水下抛石体的识别精度,构建了预留有内部空洞的抛石体物理模型与电阻率层析扫描模型研究电阻率层析扫描技术在水下抛石体内部空洞探测中的成像效果,并与传统克里金插值法效果进行了对比。结果表明:电阻率层析扫描可以有效识别水下抛石体中的空洞,并且在刺激源数量为6时电阻率层析扫描模型模拟精度达到较高值;电阻率层析扫描技术在通道纵剖面上的识别能力要远高于传统克里金插值法;将数值模拟结果中电导率大于300μS/cm的区域视为空洞区,整体反演结果略大于真实值,在x、y、z 3个方向上的偏差分别为2.73、1.75、6.95 cm;基于反演结果对电阻率层析扫描模型进行正演,正演结果与实测数据的拟合度超过0.95,证明了电阻率层析扫描模型反演的准确性。

In order to improve the recognition accuracy of the underwater riprap,the physical model and resistivity tomography model of the riprap with internal cavities are established.The performance of resistivity tomography technology in the detection of internal cavities inside the underwater riprap is studied and compared with the traditional Kriging interpolation.The results show that the resistivity tomography can effectively identify the internal cavity in the underwater riprap and the inversion accuracy reaches a higher value when the number of stimulation points increases to 6.The identification ability of the resistivity tomography on the longitudinal section of channel is much higher than that of the traditional Kriging method.Meanwhile,if the region with conductivity greater than 300μS/cm in inversion results is regarded as a cavity region,the overall inversion results are slightly larger than the real situation,and the deviations in the three directions of x、y、z are 2.73,1.75,and 6.95 cm,respectively.Based on the inversion results,the forward calculation of the resistivity tomography model is carried out.It can be found that the fitting degree between the forward modeling and the measured data was 0.95,which proved the accuracy of the resistivity tomography inversion.