基于振动法的岩块纵波波速测试

评价岩体完整性的定量指标K_v取决于岩体与岩块的纵波波速,因此准确地测得岩块纵波波速是评价岩体完整性的关键环节之一。提出了利用振动法测量岩块纵波波速即利用布设在岩块两端横截面中心的两个振动加速度传感器采集振动信号,通过互相关函数计算到时差,从而求得纵波波速。通过振动法和超声波法对不同岩性、尺寸、风化程度的8个岩块进行波速测试,分析了各因素对岩块纵波波速测试结果的影响。结果表明:振动法与超声波法测得的岩块纵波波速最大相对误差为-8.57%。采用振动法测试岩块纵波波速能有效减少频散效应对波速的影响,提高了测试精度。

Compression Wave Velocity Test of Rock Block Based on Vibration Method

The quantitative index of evaluating rock mass integrity is the rock integrity coefficient K_v which is depend on the compression wave velocity of rock mass and rock block, so accurately measuring the compression wave velocity of the rock block is one of the key steps in evaluating rock mass integrity. In this paper, the compression wave velocity of the rock block is measured by vibration method: the vibration signals are received by two vibration acceleration sensors arranged in the center of cross section at both ends of the rock block, and the arrival time difference are calculated by the cross-correlation function, so as to obtain the compression wave velocities. The wave velocities of eight rock blocks with different lithology, size and weathering degree were measured by vibration method and ultrasonic method, and the influence of each factor on the test results of rock block compression wave velocity is analyzed. The experimental results show that the relative error of rock block compression wave velocity measured between vibration method and ultrasonic method is as high as-8.57%, and measuring the compression wave velocity of rock block by vibration method can effectively reduce the influence of dispersion effect on wave velocity and improve the test accuracy.