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对于一种确定的岩体材料而言,岩体的变形参数与强度参数存在一种必然的内在联系。从材料性质来看,强度折减法的本质就是在当前边坡构型和岩体重度条件下,寻找另一种合适的岩体材料使边坡恰好达到临界状态。显然,若只对黏聚力和内摩擦角进行折减而其他参数保持不变,折减后的材料参数则可能违背岩体强度与变形参数之间存在的必然联系,即新找到的岩体材料客观上不存在。因此,在对黏聚力和内摩擦角进行折减时,有必要对岩体的其他力学参数进行调整。基于以上认识,提出了一种考虑变形与强度参数协调折减的强度折减法,探讨了变形参数(弹性模量和泊松比)、抗拉强度对安全系数、塑性区的影响,结果表明,同时考虑变形参数与强度参数协调折减的方案所得的安全系数最小,与极限平衡法的计算结果最为接近,且该方案所得的剪切塑性区主要集中在临空面附近,边坡模型中下部的剪切塑性区范围较小,同时,在边坡顶部区域出现张拉屈服区,此种塑性区分布范围最接近边坡实际破坏状态。
For a certain rock mass, there is a necessary internal relationship between deformation parameters and strength parameters of the rock mass. From the perspective of material properties, the essence of strength reduction method is to look for another suitable rock mass material under the current slope configuration and severe rock mass condition so that the slope just reaches the critical state. Obviously, if only the cohesion and internal friction angles are reduced and the other parameters remain unchanged, the reduced material parameters may violate the necessary relationship between the rock mass strength and the deformation parameters, that is, the newly found rock mass Material does not exist objectively. Therefore, it is necessary to adjust the other mechanical parameters of the rock mass when the cohesion and internal friction angle are reduced. Based on the above understanding, a method of strength reduction, which takes into account the coordination and reduction of deformation and strength parameters, is proposed. The effects of deformation parameters (elastic modulus and Poisson’s ratio) and tensile strength on the safety factor and plastic zone are discussed. Considering the compromise between the deformation parameters and the strength parameters, the safety factor obtained is the least, which is the most close to the result of the limit equilibrium method. The shear plasticity zone obtained by this solution is mainly concentrated near the free surface, The range of shear plasticity zone is small, and at the same time, the tension yield zone appears in the top of the slope. The distribution range of this plastic zone is the closest to the actual failure state of the slope.