动态扰动触发岩石破坏过程与机理研究

发布时间：2018-04-24 22:06

本文选题：动态扰动 + 蠕变与应力松弛　；参考：《燕山大学》2016年硕士论文

【摘要】：地下岩体由于其自重和地球构造的原因,处于高地应力状态,内部储存有较大的能量。通常在矿井开挖、爆破等动态扰动情况下会改变岩体原有状态,同时伴随有变形、应力和能量的变化,这些变化使得岩石稳定性状态较难确定。因此,开展岩石动态扰动模拟试验研究对于分析岩石瞬时动力扰动下发展状态有着至关重要的作用。处于准静应力、应变状态下的岩石可以保持长时间稳定状态,并表现出流变性能,瞬时动态扰动可打破原有的稳定状态并诱导岩石发生破坏。基于此,本文采用位移加载单轴压缩方式,对岩石进行高应力动态加载模拟试验。对试验进行分析整理,得到多种不同试验结果:1在高应力稳定状态下施加动态扰动直接导致了岩石的破坏;2动态扰动过程中岩石未立即发生破坏,而是在扰动后岩石缓慢发展至脆性破坏,称为延时脆性破坏;3动态扰动过程中岩石未立即发生破坏,并且岩石在后续长时间内保持稳定未出现破坏的征兆。在稳定过程中岩石处于蠕变与应力松弛的耦合状态,并由此耦合状态演化至脆性破坏。对试验数据进行深入细致整理,得到了岩石应力、变形全过程曲线。试验表明,初始加载应力、变形是能使试验发生破坏的首要条件,动态扰动是诱导破坏发生的重要条件。超过“岩石强度极限邻域”内时岩石会在动态扰动下发生破坏,邻域下限值约为单轴极限强的80%;岩石宏观裂缝分为两种:一种为沿对称截面竖直方向呈“Y”型半劈裂裂缝,另一种为沿对角线方向呈“X”型裂缝;岩石应力和变形会出现相应的临界幂律特性,初期具有近似-4/5次幂的幂律奇异性,后期具有近似-1次幂的幂律奇异性;应力松弛现象主导了能量的释放,蠕变现象主导能量的储存;稳定时间与扰动加载应力之间具有幂次关系,试验时间与扰动残余变形之间具有线性关系。
[Abstract]:The underground rock mass is in the state of high ground stress due to its gravity and the earth structure, and there is a large amount of energy stored in the underground rock mass. The original state of rock mass is usually changed under dynamic disturbance such as mine excavation, blasting and so on. At the same time, the changes of deformation, stress and energy make it difficult to determine the stability state of rock. Therefore, the study of rock dynamic disturbance simulation plays an important role in analyzing the development state of rock under instantaneous dynamic disturbance. The rock under quasi-static stress and strain state can be kept stable for a long time and show rheological properties. The transient dynamic disturbance can break the original stable state and induce rock failure. Based on this, the high stress dynamic loading simulation test of rock is carried out by using displacement loading uniaxial compression method. Through the analysis and arrangement of the tests, many different test results were obtained. The dynamic disturbance exerted by 1: 1 under the condition of high stress stability directly led to the failure of rock in the process of dynamic disturbance. However, the rock slowly develops to brittle failure after disturbance, which is called delayed brittle failure during dynamic disturbance, and the rock is not destroyed immediately in the process of dynamic disturbance, and the rock remains stable for a long period of time, and there is no sign of failure. In the process of stabilization, the rock is in the state of creep and stress relaxation, and the coupling state evolves to brittle failure. The whole process curve of rock stress and deformation is obtained by finishing the test data in detail. The experimental results show that the initial loading stress and deformation are the primary conditions for the failure of the test, and the dynamic disturbance is the important condition for inducing the failure. When the rock strength limit neighborhood exceeds "rock strength limit neighborhood", the rock will be destroyed under dynamic disturbance, the lower limit value of the neighborhood will be about 80 parts with uniaxial limit strength, the macroscopic fracture of rock can be divided into two types: one is "Y" type semi-splitting fracture along the vertical direction of symmetrical section, The other is the "X" fracture along the diagonal direction, the stress and deformation of the rock will have the corresponding critical power law characteristic, which has the power law singularity of approximate -4 / 5 power in the initial stage and the power law singularity of the approximate -1 power in the later stage. Stress relaxation dominates energy release, creep dominates energy storage, and there is a power relationship between stability time and disturbed loading stress, and a linear relationship between test time and disturbed residual deformation.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU45

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