基于与围岩相互作用的冻结壁弹性设计理论

Elastic design theory of frozen soil wall based on interaction between frozen soil wall and surrounding rock

冻结壁设计理论是冻结法凿井技术的核心之一。传统的冻结壁厚度弹性设计公式在冻结壁与围岩的弹性模量之比小于10时有较大的误差。为了更合理地设计冻结壁,考虑了开挖卸载作用以及冻结壁与围岩的相互作用,建立了一个更符合实际的力学模型;推导出了其弹性解析解;分析了冻结壁与围岩的应力和位移变化规律;讨论了冻结壁厚度的设计方法;基于Tresca强度条件和Mises强度条件,分别建立了新的冻结壁厚度弹性设计公式。分析比较表明,新公式较传统的冻结壁厚度弹性设计公式更合理,更节省。

The design theory of frozen soil wall is one of the core technologies for mine shaft freezing sinking.The conventional elastic design formula for the thickness of frozen soil wall has large errors in case the modulus ratio of frozen soil wall to surrounding rock is less than 10.Taking into account the effect of excavation unloading and the interaction between frozen soil wall and surrounding rock,a more practical mechanical model is established for a more rational design of frozen soil wall.Its analytical solutions of elasticity are derived.The variation laws of stresses and displacements in frozen soil wall and surrounding rock are analysed.The design methods for the thickness of frozen soil wall are discussed.Based on Tresca strength condition and Mises strength condition respectively,two new elastic design formulae for the thickness of frozen soil wall are put forward.Analyses and comparisons show that the proposed formulae are more reasonable and more economical than the traditional elastic design formula for the thickness of frozen soil wall.