桩基础约束条件下季节冻土场地冻胀量的二维数值求解

Calculation of frost heave in seasonal frozen soil under piled foundation restrain condition

根据热传导理论建立水热相互迁移模型,利用有限差分方法求解二维季节冻土的时程温度场,由二维土体中水份迁移质量微分方程求解成冰量,进而得到场地的自由冻胀量。由于建筑物基础的侧表面对土体冻胀过程产生约束作用,使土体产生与冻胀相反的约束变形,因而桩基础约束条件下季节冻土场地的最终冻胀量为有限差分方法求解的自由冻胀量与约束冻胀量之差;该理论计算结果与模型试验实测值基本吻合,验证了该数值求解方法的正确性与合理性。

A hydrothermal transfer model was set up on the basis of heat transfer theory and two dimensional season frozen soil time path temperature field was solved by means of finite difference method. The quantity of ice formed was calculated by the transfer mass differential equation for water in the two dimensional frozen soil, and the free frost heave quantity in this field was obtained. Because the side fall of building foundation has a restraint effect on the soil during the course of soil frost heave, the soil will deform opposite to frost heave. So under the condition of the piled foundation restrainment, the ultimate quantity of frost heave in seasonal frozen field is the differential value between the quantity of free frost heave and the quantity of restraining frost heave calculated by finite difference method. The theoretical calculation values are basically coincident with those measured in model experiments. The correctness and rationality of the finite difference method were justified.