层理主控的白云岩隧洞围岩稳定性分析与支护对策研究

Rock bedding and the stability of surrounding rock are often regarded as two independent engineering scientific problems. The bedding has a certain impact on the strength, elastic modulus and Poisson's ratio of the slate based on our previous researches, but the mechanism is unknown. Whether there is a similar effect on the dolomite which is widely distributed in Yunnan, Guizhou and other regions, also can make nothing of it. Therefore, it becomes necessary to rebuild the rock stability analysis model under the influence of bedding. In order to reveal the failure law of bedding dolomite, we will carry out some uniaxial compression tests, Brazilian disc splitting tests and shear tests. Then, the rock micro composition will be discussed in the use of energy spectrum analyzer, and the micro-structure will be observed with the help of environmental scanning electron microscopy. The mechanisms of strength weakening and the layer-to-layer interaction will be explained for dolomite containing different bedding. On this basis, combining the spatial relations of bedding and tunnel, the theoretical model of bedding dolomite tunnel surrounding rock stability analysis will be built and the supporting measures will be put forward accordingly. With the help of some kinds of numerical simulation software, the effect of countermeasures will be analyzed, and the theoretical model will also be verified. These research results will provide a theoretical support for the construction of underground engineering in bedding dolomite areas.

岩石层理和围岩稳定性常被视作两个独立的工程科学问题，前期研究发现，层理对板岩的强度、泊松比、弹性模量等均有不同程度的影响，但作用机理不明；层理对云、贵等地广布的白云岩是否有类似影响，亦不得而知。为此，有必要重构层理影响下的岩体稳定性分析模型。课题拟以层理白云岩为研究对象，通过开展单轴压缩、巴西劈裂及剪切试验，研究其破坏规律；运用能谱分析仪分析岩样微区成分，并用电镜扫描岩样微观结构，探索含不同层理的白云岩受载后各层相互作用机制，揭示其强度弱化机理。在此基础上，结合层理与隧洞的空间关系，构建层理白云岩隧洞围岩稳定性分析理论模型，据此提出针对性的支护对策。应用数值模拟软件，分析支护对策成效，并校验理论模型，为层理白云岩地区地下工程修建提供理论支撑。

层理对滇、黔等地广布的白云岩的强度、泊松比、弹性模量等均有不同程度影响，且作用机理不明。课题围绕层理主控的白云岩隧洞围岩稳定性与支护对策问题，系统研究了层理白云岩不同层理角度、白云岩岩层厚度、接触夹层厚度、接触夹层弹性模量、接触夹层内摩擦角及接触夹层黏聚力等对其宏观力学性能的影响，并通过电镜扫描与能谱分析实验将层理白云岩的微观结构与宏观力学性能量化结合，揭示了其强度弱化机理，从而提出了有效的支护对策。基于单轴压缩试验、巴西劈裂试验、电镜扫描试验、能谱分析试验及拓印法等，量化了层理白云岩裂隙扩展规律、破坏过程及力学特性，并构建了以粘弹性本构模型为基础的层理白云岩本构方程。再结合层理与隧洞的空间关系，构建了层理白云岩隧洞围岩稳定性分析理论模型，通过数值计算对其进行校验，提出了最优支护体系。