【作者】 何峰；

【导师】 王来贵；

【作者基本信息】 辽宁工程技术大学 ， 工程力学， 2005， 硕士

【摘要】 岩石的结构是极其复杂的非连续和非均质体,其力学属性具有非线性、各向异性及随时间变化的流变特性。岩石工程结构失稳前特征即应力状态保持不变,且是突然破坏释放能量,即蠕变失稳。所以开展岩石蠕变破坏机理的研究对岩石工程的长期稳定性具有重要的理论意义和实际价值。 本文主要从岩石全程应力应变特征和蠕变曲线出发进行研究,建立蠕变失稳模型,把模型中的两个参数看作是随岩石的变形而变化,得出失稳判据和改进的蠕变方程,进而解释了岩石蠕变的第三阶段失稳现象;同时从不同角度推导出模型的各种解析解,这些方程表明岩石的本构关系、变形模量与加载条件和历史有关,验证了该模型是能描述岩石的衰减蠕变、稳定蠕变与加速蠕变三种情况的比较完善的流变模型。 结合蠕变模型和流变力学的一般解法,推导出了采空区悬顶板梁临界载荷及应力的粘弹塑性解析解,并对其稳定性进行了分析;推导出圆形洞室周围岩石任意点的位移随时间增长而变化的方程,并得出了粘塑性区半径;建立了含软弱夹层的层状边坡板梁失稳模型,改进了欧拉公式具有时间效应,提出了一种边坡失稳的分析方法。更多还原

【Abstract】 The structure of rock is extremely complicated discontinuous and heterogeneous body, its mechanics property has non-linear, anisotropism and rheology characteristic, which changed over time. The characteristic stress state of rock structure is keeping constant before its losing steady, and suddenly destroyed with releasing energy, namely creep is losing steady. So it is important theory meaning and reality value to long-term stability of rock engineering to launch research of rock creeping destroying mechanism.The text proceeds from the whole stress-strain characteristic and creep curve of rock, set up creep losing steady model, regard two parameters of model as changing with deformation of rock, draw losing steady criterion and modified creep equation, and then has explained losing steady phenomenon at the third stage of rock creep; At the same time we derived out analytical solution of the creep model from different angles, and indicate constitutive of rock and deformation of modulus which relate to the condition and history of loading, and prove that it is a perfect rheology model which can describe decay creep, stability creep and accelerate creep of rock.The text combines creep model and general solution of rheology mechanics, deriving out visco-elasto-plastic analytic solution of critical load and stress of operation goaf hanging beam, and analyzed its stability; Deriving out displacement of wall rock which increases with time changes, and has drawn radius of plasticity district; Set up losing steady beam model of slope containing weak intermediate layer, modified Euler formula has a time effect, putting forward losing steady analytical method of the slope.更多还原