利用振动法定量评价工程岩体的完整性

岩体的完整性是工程岩体质量分级的重要指标之一，在现行规范中主要通过岩体的完整性系数 、体积节理数 、结构面发育程度进行判断。工程岩体的结构面复杂，定性判断较困难，且 值需转换为 值后才可进行定量评价。目前主要采用超声波法测量 值，由于该方法激振源为超声波，工作频段窄、测量低频振动时误差较大，测试距离短，使破碎或较破碎岩体的测量结果存在较大误差。本文通过振动法测量岩体的纵波波速：在浅层钻孔中激振，利用布设在岩体表面上的多个低频传感器接受振动信号,从而实现分段测量岩体纵波波速，求得各段岩体的完整性系数，准确地评价岩体完整性。采用本文方法，对工程岩体实例的结果表明与定性评价结果一致。

Quantitative evaluation of the engineering rock integrity by vibration method

The rock mass integrity is one of the important indexes of engineering rock mass quality classification. In the current codes, it is mainly evaluated by the integrity coefficient , the volumetric joint count and the development degree of structural plane. The structural plane of engineering rock mass is complex. It is difficult to judge qualitatively, and the value should be converted to value. At present, the ultrasonic method is mainly used to measure , with the vibration source is ultrasonic wave, and the working frequency band is narrow, the error is large, and the test distance is short, especially for broken or relatively broken rock mass. In this paper, the compression wave velocity of the rock mass is measured by vibration method: the vibration is excited in the shallow borehole, and the vibration signals are received by many low-frequency sensors arranged on the surface of rock mass, thus the compression wave velocities are measured section by section. The integrity coefficients of each section can be obtained, form which the integrity of rock mass can be evaluated accurately. By using the method in this paper, the results of engineering rock mass examples show that it is consistent with the qualitative judgement.