摘要
Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of almost all types of rocks, A nonlinear Hock-Brown failure criterion is employed to estimate the supporting pressures of shallow tunnels in limit analysis framework. Two failure mechanisms are proposed for calculating the work rate of extemal force and the internal energy dissipation. A tangential line to the nonlinear failure criterion is used to formulate the supporting pressure problem as a nonlinear programming problem. The objective function formulated in this way is minimized with respect to the failure mechanism and the location of tangency point. In order to assess the validity, the supporting pressures for the proposed failure mechanisms are calculated and compared with each other, and the present results are compared with previously published solutions when the nonlinear criterion is reduced to linear criterion. The agreement supports the validity of the proposed failure mechanisms. An experiment is conducted to investigate the influences of the nonlinear criterion on collapse shape and supporting pressures of shallow tunnels.
线性失败标准广泛地在对浅隧道起作用的地球压力的计算被使用。然而，试验性的证据证明那个非线性的失败标准能表示相当，很好，几乎所有的失败岩石打字。一个非线性的 Hoek 布郎失败标准被采用在限制分析框架估计浅隧道的支持的压力。二失败机制为计算外部力量和内部精力驱散的工作率被建议。到非线性的失败标准的一根正切的线被用来作为一个非线性的编程问题提出支持的压力问题。这样提出的客观功能关于失败机制和接触点的地点被最小化。以便估计有效性，为建议失败机制的支持的压力被计算，当非线性的标准被归结为线性标准时，与对方，和礼品相比，结果与以前出版的答案相比。协议支持建议失败机制的有效性。一个实验被进行在倒塌形状和浅隧道的支持的压力上调查非线性的标准的影响。
基金
Foundation item： Project（2013CB036004） supported by the National Basic Research Program of China
Project（51178468） supported by the National Natural Science Foundation of China
