Analysis and discussion on testing methods of broken rock zone of surrounding rock of roadway

The paper introduced different testing methods and testing theories for broken rock zone of surrounding rock of roadway, discussed and analyzed advantages and disadvantages and scope of application of the different testing methods. By comparison, it got conclusion as follows: technology of the acoustic method is advanced and testing method is simple, but it is difficult to be applied in soft rock; the multi-point displacement measurement and the multi-point stress measurement can be applied for real-time monitoring of surrounding rock displacement or stress, but the accuracy of measurement is limited; the seismic wave method has high testing precision, but its equipment is expensive and complicated to install; the geologic radar method without drilling is a non-destructive testing method, but testing cost is high; the resistivity method has a high requirement in the precision of instrument and arrangement of electrodes; image resolution of the method of borehole camera is limited by harsh environmental conditions within the borehole and the pixel of camera. Therefore, each testing method has its limitations, nature of the surrounding rock should be considered in actual application to select appropriate method for accurate determination of broken rock zone of the roadway.