冻结管对冻土试件自身抗拉性能的强化效果分析

Analysis on strengthening effect of freezing pipe to self-tensile performances of frozen soil specimen

为了更加精准地开展人工冻结法设计,以存在冻结管的冻土试件为研究对象,利用冻结管-冻土接触面强度试验数据为条件,建立数值计算模型,对不同工况下的冻土试块的应力分布及其服役性能进行研究。研究结果表明:在所有计算中冻结管-冻土接触面未发生破坏,且冻结管的存在会有效降低冻土试块的最大拉应力;在计算中单冻结管试件最大拉应力比无冻结管试件降低1 1%,双冻结管试件最大拉应力比无冻结管试件降低17%。冻结管对于抗拉性能的提升主要受其布置位置影响,冻结管规格对强化效果的影响相对较小,在设计中可以忽略。最终根据研究结果提出了同时考虑冻土帷幕厚度、平均温度及其内部冻结管布置高度的设计思路。

In order to more accurately make a design of an artificial ground freezing method,taking a frozen soil specimen existed in the freezing pipe as a study object,with the strength test data of the contact surface between the freezing pipe and freezing soil as the condition,a numerical calculation model was established and was applied to study the stress distribution and its service performances under different working conditions.The study results showed that there was no destroy occurred on the contact surface between the freezing pipe-freezing soil in all calculations and the freezing pipe existed would effectively reduce the max tension stress of the frozen soil specimen.In the calculation,the max tension stress of the single freezing pipe specimen would be reduced by 11%than the no freezing pipe specimen and the max tension stress of the double freezing pipe specimen would be reduced by 17%than the no freezing pipe specimen.The tensile performance improvement by the freezing pipe would be mainly effected by the layout position.The specification of the freezing pipe would have a relatively little effect on the reinforcement effect and could be ignored in the design.Finally,according to the study results,the design ideas were provided in consideration of the freezing soil curtain,average temperature and internal freezing pipe layout height.