中文摘要：

在多圈管冻结条件下冻结管受力变形规律的课题研究过程中,首先针对未开挖时冻结管的各向应力应变变化规律,以相似理论为基础开展物理模拟试验,得出结论：未开挖阶段的冻结管变形在冻结前期基本完成;黏土层中冻结管应变量比砂土层大;黏土层中冻结管最大拉应力为97.7MPa,最大压应力为161.5MPa,弯曲应力为轴向应力的1.7倍,最大弯曲应力达到冻结管屈服荷载的0.62倍,而砂土层中均很小。为改善冻结管的受力性能,减少开挖前冻结管储存的应变能,降低后期开挖时候冻结管的破坏率提供了实验依据。

英文摘要：

In order to study the stress and deformation law of freezing pipes during multi-circle freezing, model tests are carriedout based on the similarity theory. The multi-direction law of the freezing pipes under deep ground pressure before excavationis acquired. The following conclusions are drawn through analysis： the deformation of freezing pipes before the stage ofexcavation is completed during the ealier freezing stage; the strain of freezing pipes in clay stratum is larger than that in sandstratum; the maxmium tension stress in clay stratum is 97.7 MPa, while the maxmium compression stress is 161.5 MPa, and thebending stress is 1.7 times the axial one. The maxmium bending stress is 0.62 times the yield load of freezing pipes, while thesestress is very small in sand stratum. The model test aim to improve the stress performance of freezing pipes, to reduce the strainenergy storaged in freezing pipes before excavation and to reduce the failure rate of freezing pipes during excavation.