设置1-2根圆形冻结管时冻结水泥土搅拌桩温度场数值对比分析

Temperature Field Comparison of Freeze Cement Mixing Piles with 1-2 Circular-shaped Freezing Piles by Numerical Simulation

为解决现有人工冻结法施工后周围地层产生冻胀融沉所引发不良后果的问题,冻结水泥土搅拌桩应运而生。本文对冻结水泥土搅拌桩的施工工艺作了简单介绍,运用有限元软件对设置1-2根圆形冻结管时冻结水泥土搅拌桩的温度场发展规律进行了数值对比分析。主要得出:冻结水泥土搅拌桩在保证地层承载力和防水性能的基础上,既可提高水泥土搅拌桩的抗剪和抗弯能力,也可减少水泥用量;设置1根冻结管交圈所用时间是设置2根冻结管的4倍;冻结40d时,设置2根冻结管比设置1根冻结管的冻土墙厚度厚0.6m;路径1上各点离冻结管越远降温越慢,降温速度先快后慢,由盐水降温计划所决定;当使用冻结水泥土搅拌桩施工时,建议采用设置2根冻结管的形式。所得结果可为今后类似工程设计提供理论参考依据。

In order to solve the frost thaw settlement problems caused by adverse consequences in the artificial freezing method after the construction of the surrounding formation, the freeze cement mixing pile emerged. A brief introduction to the construction process of freeze cement mixing piles was made, then the finite element software was used to make numerical comparisons on the devel- opment laws of temperature field while setting 1-2 root canal circular freeze cement mixing piles. The results showed that the shear and flexural capacity of freeze cement mixing piles could be improved and the consumption of cement could be reduced while ensuring the bearing capacity and waterproof performance. The cross lap time of setting a freezing pipe was 4 times of that setting two freezing pipes. After freezing for 40 days, the wall thickness of permafrost with two freezing pipes was 0. 6m thicker than setting one freezing pipe. The farther each point on the path of a frozen pipe, the slower the cooling, and the cooling speed slowed down after that, which was determined by the brine cooling plan. When freeze cement mixing piles were used in construction freeze, it is suggested to use two freezing pipes. The results can provide a theoretical reference for future similar projects.