关键词: 地应力场, 冻结壁, 围岩, 卸载, 弹性分析

Abstract: To obtain the stress and deformation of circular frozen wall in bi-directional unequal ground stress field, an elastic mechanical model of frozen wall interacting with surrounding rock has been established with the excavation unloading considered. The analytical solution has been derived and verified by finite element software，which has also been compared with the traditional loading model. The hoop stress and radial displacement distributions in the inner edge of frozen wall have been analyzed emphatically as well as their relationship with different influencing factors. The results have shown that the calculation results of the loading model are overall larger than the unloading model. When the elastic modulus ratio β between frozen wall and surrounding rock has a small value, the consideration of their interaction can decrease the stress and displacement effectively. If the ground stress uniformity coefficient λ is small enough, the tensile hoop stress will appear in the inner edge of frozen wall, which is not conducive to the full play of its carrying capacity. In addition, unloading rate, β, λ, and frozen wall’s radius ratio all have significant impact on the stress and displacement of frozen wall, while the influence of the Poisson’s ratio is relatively small. On the whole, the calculation model in this paper can really reflect the stress and deformation of frozen wall, and the research findings can guide the frozen wall’s design and construction.

Key words: ground stress field, frozen wall, surrounding rock, unloading, elastic analysis