巷道(隧道)围岩稳定蠕变上下阈值及确定方法

Stable creep upper and lower thresholds in roadway(tunnel) surrounding rock and it's determination method

基于岩石蠕变特性和稳定蠕变终止轨迹线的形成机理,揭示了岩石稳定蠕变上下阈值的存在并给出了试验确定方法。剖析了围岩径向各点不同的加载路径和不同的载荷终止水平对围岩变形分区形成的影响,并以此为基础揭示了稳定蠕变上下阈值在围岩中的基本属性。利用弹性区环向应力与径向应力之间的关系直线和不同围压下的稳定蠕变上下阈值拟合直线给出了围岩中塑性硬化区内外边界应力的确定方法。研究成果可为围岩应变软化模型的正确建立、围岩变形分区的科学研究及支护参数的量化设计提供参考。

Based on the rock creep characteristics and the formation mechanism of stable creep termination trajectory line,the existence of rock stable creep upper and lower thresholds is revealed and the test determination method is given.The influence of the different loading paths and different load termination levels on surrounding rock deformation zoning is analyzed.With the above work,the basic properties of stable creep upper and lower thresholds in surrounding rock are found.In order to obtain the determination method of internal and external boundary stress of the plastic hardening zone in the surrounding rock,not only the linear relationship between the hoop stress and the radial stress in the elastic zone is utilized,but also the fitting lines of the stable creep upper and lower thresholds under different confining pressures are used.The results have an important reference value for the correct establishment of the strain softening model,the scientific research on the deformation zone of surrounding rock and the quantitative design of supporting parameters.