加卸载应力条件下脆性花岗岩变形的试验研究

隧道开挖过程中，岩石的变形破坏是在复杂应力条件下发生的。通过对脆性花岗岩试样进行加轴压、卸围压的三轴实验来分析其破坏的成因，发现一些新的问题：在适当围压条件下，围压的大小、加压速率及卸载速率都对岩石的破坏有较大的影响。因此，在隧道开挖过程中，必须控制好隧道的开挖速度；在设置围岩支护时，必须保证支护体有足够的强度、刚度，并且能适应围岩的变形，只有这样才能有效防止岩石变形的破坏，保证施工的顺利进行。

Research on the Stress Conditions of Brittle Granite Deformation with the Loading and Unloading Experiment

In the process of tunnel excavation,the deformation and failure of the rock is attributed to the complex stress conditions.Based on the brittle granite specimen axial compression and unloading confining pressure destructive testing to analyze the mechanical properties,we discovered some new problems：un-der appropriate conditions of confining pressure,the confining pressure,pressurization rate and unloading rate have obvious impact on the rock failure.Therefore,during the process of construction,we need keep the speed of tunnel excavation under good control;and at the same time,we must ensure that the support system must have sufficient strength and stiffness,and can adapt itself to the deformation of surrounding rock,so that we can effectively prevent the rock failure,and ensure the construction success.