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软岩巷道过大的径向位移对煤矿生产有较大影响。基于双屈服面模型,利用某种泥岩材料的常规三轴实验数据,分别拟合了以第一、第三塑性主应变(ε_1~p,ε_3~p)为硬化参量的加载面,根据对完全加载假设的验证,推导了此泥岩材料的非关联流动法则,得到了围岩塑性区范围和径向位移的解。研究结果表明:该泥岩材料的2个加载面形式为二次函数,各项系数均可表示为ε_1~p或ε_3~p的一次函数,由此确定塑性应变增量分量的大小;推导出的非关联流动法则中含有常数项,其原因为:在加载过程中,会先达到以ε_3~p为硬化参量的加载面,当ε_1~p恰好为0时,ε_3~p即为该常数的值;考虑了岩石的非线性应变软化特征,排除了“人为假定流动法则”等主观因素的干扰,求解了塑性区范围和径向位移的解析解,得到了在一定地应力和该岩性条件下二者与开挖半径的线性拟合公式。
The excessive radial displacement of soft rock roadway has great influence on coal mine production. Based on the dual yield surface model and using the conventional triaxial experimental data of some kinds of mudstone materials, the loading surface with the first and third plastic principal strains (ε_1 ~ p, ε_3 ~ p) Loading hypothesis verification, deduces the non-associated flow law of this mudstone material, and obtains the solution of the plastic zone range and radial displacement of the surrounding rock. The results show that the two loading surfaces of the mudstone material are quadratic functions and all the coefficients can be expressed as a linear function of ε_1 ~ p or ε_3 ~ p, so as to determine the size of plastic strain increment component. The reason for the non-associated flow rule is that there is a constant term because the loading surface with ε_3 ~ p as the hardening parameter will be reached first. When ε_1 ~ p is exactly 0, ε_3 ~ p is the value of this constant Considering the nonlinear strain softening characteristics of rock and eliminating the interference of subjective factors such as “artificial hypothetical flow law ”, the analytic solution of the plastic zone’s range and radial displacement is obtained. Linear Fitting Formula of Both and Excavation Radius Under Condition.