顺层围岩地下洞室的粘弹性稳定

应用粘弹性薄板的稳定方程和Laplace变换方法,采用承受平行于中面的均匀压力的四边简支的岩板力学模型,根据岩板屈曲变形时的特点及其边界条件,研究了地下洞室中外层岩板向临空面变形并导致层间脱离的状况,导出了岩板结构与时间相关的临界载荷和临界应力的解析式。结果表明岩层的稳定性与岩体的流变性质密切相关,在一定载荷下或应力水平下,随时间延长会发生滞后失稳,表现出了与弹性性态不同的特性。分析了某工程地下洞室层状岩体的稳定性,通过分析比较说明文中分析方法的有效性。

Viscoelastic stability of cavity bedding wall rock

According to the boundary condition and feature of rock plate bucking deformation, stability equations and Laplace transform method of viscoelastic thin plates, and a mechanical model for the rock plate that simply supported on four sides and bears homogeneous pressure parallel to the neutral surface, are applied to investigate the interformational separation formed by outer rock plates deformation of the underground cavity toward the free face. Analytic expressions for the structure of rock plates are established based on the relation between the time-dependent critical load and critical stress. The results show the close relation between the stability and rheological property of the rocks. When lagged instability occurs under given load or stress with mining time going on, rocks show a different property from flexibility. The availability of the hypothetical theory is verified through a practical analysis of the stability of an underground cavity bedded wall rocks in a program.