基于热力耦合的砼衬砌渠道冻胀开裂数值模拟

在我国北方地区，衬砌渠道的冻胀破坏现象严重阻碍着渠道的正常运行，冻胀问题亟待解决。根据砼梯形衬砌渠道的受力特点，在对渠道冻胀现象进行了适当简化和合理假设的基础上，通过使用扩展有限元方法XFEM，直接建立了温度荷载和裂纹发展之间的关系，对渠道的砼衬砌结构在温度应力作用下裂纹产生的位置进行了预测，模拟了裂纹在冻胀作用下的扩展形式和破坏状态。模拟结果直观分析了梯形渠道在冻胀作用下从阴坡到底板再到阳坡依次破坏的过程，解释了不均匀冻胀会影响各部分冻胀破坏程度的原因，验证分析了渠道衬砌板的裂纹为I+Ⅱ型复合裂纹和因此产生的受力状态，从而为渠道抗冻胀设计提供了分析办法。

Thermomechanical coupled model for frost heaving cracking of concrete lined channel

In the northern part of China,the phenomenon of frost heaving destruction of the lining channel seriously hinders the normal operation of the canal.When the concrete lining plate can not bear frost heaving force or frost heave deformation of the soil under the channel,frost heaving damage will ocure,such as crack and even rupture.Based on the theory of frost heaving and the theory of thermo-mechanical coupling,the numerical simulation of a trapezoidal channel is carried out by using linear elasticity model.The generation and development of the crack in the trapezoidal lining channel under the temperature load are numerically simulated by the combination of the thermo-mechanical coupling method and the extended finite element method.It can be visually observed that the generation and developing process of cracks in the concrete lining structure under the temperature load,provide useful reference for improving the design method of lining mechanism and extend the further application of finite element.