圆形水平冻结壁弹性设计理论

针对目前水平冻结壁设计中存在的不足,在考虑冻结壁内侧岩土体开挖卸荷作用的情况下建立了圆形水平冻结壁与围岩相互作用弹性力学模型,得到了其应力、位移解析解,着重分析了冻结壁内缘的受力情况,并基于不同屈服准则建立了冻结壁厚度的计算公式,分析了各因素对冻结壁厚度的影响。研究结果表明:考虑与围岩相互作用可有效降低水平冻结壁厚度,相互作用越强,厚度越小;冻结壁厚度随水平侧压力系数增大而减小,随其埋深增大而增大,与此相比,泊松比的影响可忽略不计;考虑到冻土为摩擦型材料,建议计算时采用Mohr-Coulomb屈服准则。

Elastic design theory of circular horizontal frozen wall

In order to overcome the deficiency in the design of horizontal frozen wall，an elastic mechanical model was established for understanding the interaction between circular horizontal frozen wall and surrounding rock，with the consideration of the excavation unloading effect of rock and soil inside frozen wall.At the same time the analytical solutions of stress and displacement were obtained.The stress on the inner edge of frozen wall was analyzed emphatically and the formula for calculating frozen wall thickness was put forward based on different yield criteria.The influence of various factors was also discussed.The analysis shows that the frozen wall thickness can decrease significantly with the consideration of the interaction.The frozen wall becomes thinner with stronger interaction and larger lateral pressure coefficient and becomes thicker with the increase of its buried depth.However，the influence of Poisson’s ratio on the thickness can be neglected.In addition，the Mohr-Coulomb yielding criterion is suggested to calculate the thickness as frozen soil belongs to geomaterial.