缓倾薄层弱结构松动圈声波测试时测孔布置的理论依据与验证

从层状岩体的力学特性、声波在层状岩体中的传播规律、围岩塑性区和剪裂区的分布特征3个方面,对缓倾薄层弱结构松动圈声波测试测孔布置的理论依据进行研究,提出声波测孔布置3项基本原则,即:巷道两帮测孔顺层布置;顶底板测孔垂直于岩层布置;塑性区和剪裂区较大部位加大声波测孔控制深度.基于测孔布置的理论和原则,在工程中合理设计声波测孔布置方式.基于测孔布置的理论和原则,在某矿山巷道松动圈声波测试时改进声波测孔布置方式.测试结果表明:顺层和垂直于岩层的测孔布置方式获得的纵波波速vp与孔深L的曲线规律明显,克服了常规布置方式带来的vp-L曲线无序变化的缺陷,可容易确定出倾斜薄层弱结构松动圈范围.

Theory basis and practice of acoustic measuring boreholes arrangement for broken rock zone in gently inclined thin layer weakness structure

Theoretical basis of the acoustic measuring boreholes arrangement for broken rock zone test in gently inclined thin layer weakness structure was studied through analyzing the mechanical characteristics of layered rock mass, the propagation rule of acoustic and distributions characteristics of plastic zone and slip zone in layered rock mass. And three principles of the acoustic measuring boreholes arrangement were proposed, i.e., the measuring boreholes in two sides were parallel to the strata, the measuring boreholes in the roof and floor perpendicular to the strata, and the controlling depth of the measuring boreholes in the scope of the large plastic zones or the large slip zones should be increased. When the broken rock zone of roadway was tested by the acoustic way in a certain mine, the acoustic measuring boreholes arrangement mode was improved on the basis of the theory and principle. In the engineering, the acoustic measuring boreholes arrangement mode was designed reasonably based on its theory and principles. The results show that the vp?L curve obtained by new arrangement mode through measuring boreholes parallel and perpendicular to the strata has a very good regularity and overcomes the flaw of the vp?L curve disorder change caused by conventional arrangement mode. The improved arrangement mode can determine the scope of the broken rock zone in the gently inclined thin layer weakness structure quickly.