论文部分内容阅读
为了深入研究巷道围岩卸荷破坏裂隙发展规律,针对试验考察巷道突然开挖卸荷后周边围岩裂纹的扩展状况,自行设计巷道卸荷试验装置和试验方法,采用有机玻璃板模拟围岩,中心挖去缺口部分代表巷道,遵循试验模拟的相似模型准则来设计试验,并采用高速摄影方法对模型裂缝的发展进行拍摄.试验结果表明:围岩中的弱面不但是加载过程中最容易破坏的位置,也是卸荷破坏过程中强度最薄弱的位置;裂纹的扩展方向与主要卸荷方向垂直,属于拉伸破坏类型;卸荷后在巷道的角部产生了拉应力集中.
In order to study the law of the development of roadway surrounding rock unloading failure, in view of the experimental study of the expansion of the surrounding rock after the tunnel excavation unloading the unloading test device and test method, the use of plexiglass plate to simulate the surrounding rock, The center digging the gap part of the representative roadway, follow the experimental simulation of similar model criteria to design the test, and the use of high-speed photography method to model the development of cracks.Experimental results show that: the weak rock in the surrounding rock is not only the most vulnerable to damage during loading Which is also the location with the weakest strength during unloading failure. The direction of crack propagation is perpendicular to the main unloading direction and belongs to the type of tensile failure. After unloading, the stress concentration in the corner of the roadway is concentrated.