车载下冻土路基稳定性的有限元计算分析

根据车载下冻土路基受力特征，应用虚拟裂纹的概念，并考虑了冻土特有的冰体胶结力作用，提出了路基稳定性的二维模型。应用断裂力学理论，对车载下路基简化模型进行理论推导，建立了在车载及胶结力作用下的路基破坏过程的计算公式，可以计算路基破坏的特征参数，为路基稳定性设计提供参考和依据。在计算方法上采用了半解析有限元法，即计算车载引起的破坏用有限元法，计算胶结力引起的破坏用解析法，然后将二者结合起来计算整个破坏过程。给出了数值算例，计算了不同土质的破坏过程及特征值，与理论预测值相符，说明了方法的有效性。

The stability analysis of frozen soil roadbed under vechicle loads using finite element method

Based on the consideration of fictitious crack and the cementation force of ice in the frozen soil, the two dimensions model of frozen soil roadbed stability arc proposed. Referenced the fracture mechanics theories, simplified the roadbed model under vehicle loads, the formula for calculation frozen soil roadbed failure process under the vehicle loads and cementation force is established. The formula can calculate the parameter of roadbed failure process and offer the reference for the stability design of roadbed. Semi-analytical finite element method is adopted for calculating the model. The finite element method is used to calculate the frozen soil roadbed failure caused by vehicle loads, the analytic method is used to calculate the failure caused by cementation force on the crack tip. Then two methods are cou- pling to calculate the whole failure process. Finally the numerical examples that calculated different types of frozen soil roadbed are given. Compare with the experimental value in the frozen soil compress experiment, the result value is accord well.