应用超声波法探测边坡薄弱层

Ultrasonic Method for Detecting Weak Plane in Slope

露天煤矿边坡稳定是影响矿山正常开采重要因素之一。目前利用钻孔采取岩芯是探测边坡薄弱层的主要方法。由于岩芯采取率低,尤其对厚度较小的能引起滑坡的薄弱层不易取芯,常常丢失,可靠性较差。为了解决钻孔取芯的缺点,我们研制了超声波弱层探测仪。该仪器是根据岩体对声波的传播速度与岩体的密度、力学强度等密切相关的理论为基础的,只要测量出岩体的声速。

Slope stability is one of the important factors that affect coal mining in open-cast mine.Currently the method for detecting weak plane is mainly core drilling,which has a low rate of core recovery and therefore it might miss the weak plane easily.An ultrasonic detector is developed by Fushun Research Institute of Central Coal Mining Research Institute,based on the following principles:1.sound velocity changes with properties of rock mass,it is generally high up to 5-6 km/s in igneous and metamorphic rocks,and it is only 1.5-3km/s in badly cemented sedimentary rock,2.sound velocity changes with variation of density and porosity,it increases with increased density and it reduces considerably with increased porosity.This instrument can detect variation of sound velocity in different type of rock,and it can judge the position of weak plane that might cause slip based on magnitude of velocity.Commercial tests conducted in Haizhou surface mine in Fuxin and West surface mine in Fushun show that the results measured by the instruments conform with actual geological data.