运用弹性波CT法检测堰塞坝体密实性的可行性研究

Feasibility study on using elastic CT method to detect the density of weir dam

堰塞坝体与一般岩体相比,结构十分松散,不利于弹性波的传播,笔者利用大功率震源,高灵敏检波器开展弹性波CT试验,评价其在堰塞坝体密实性评估中应用的可行性。正演模拟结果表明,弹性波CT法基本能够反映松散堆积体的内部介质结构和波速情况;现场堰塞坝堆积体上开展的钻孔内弹性波CT法测试反演波速与钻孔岩芯对比显示具有较好的对应性,CT速度剖面可以综合反映钻孔间岩土体的密实情况。可见通过弹性波CT方法得到的纵波速度可对堰塞坝体地下密实性进行有效评价。

Compared with ordinary rock mass,the structure of the weir dam is very loose,which is not conducive to the propagation of elastic waves.In this paper,a high-power source and a high-sensitivity geophone are used to carry out elastic CT tests to evaluate its application in the evaluation of the compactness of the weir dam feasibility.The results of forward modeling show that the elastic CT method can reflect the internal medium structure and wave velocity of the loose accumulation body;the inversion wave velocity of the elastic CT method in the borehole carried out on the on-site dam accumulation body is compared with the drill core.With good correspondence,the CT velocity profile can comprehensively reflect the compactness of rock and soil between boreholes.The results of this paper show that the longitudinal wave velocity obtained by the elastic CT method can effectively evaluate the underground compactness of the weir dam.