摘要
岩体含水是岩体失稳的重要因素之一。将传统西原模型的线性牛顿体改为非线性牛顿体,克服了传统西原模型不能反映加速蠕变阶段非线性特征的缺点;考虑水对岩体蠕变的影响,将改进西原模型的模型参数设为含水率的函数并引入P元件,P元件所产生的变形代表是由水压的作用引起的变形量;为了量化水压对蠕变变形的影响提出水化因子λ的概念;蠕变过程中岩体的蠕变参数具有时效性,借助损伤力学的方法可以有效地实现岩体材料的劣化及蠕变参数的非定常特性;模型参数中蠕变寿命和极限强度由蠕变试验确定,其余参数由蠕变试验数据运用1st Opt软件反演得到;最后将蠕变模型应用于开挖岩体的蠕变分析中,发现岩体中的水增加了井壁的应力水平,加快了井壁的蠕变变形,这对工程实践有重要的指导意义。
Water contained in the rock mass is an important factor in the instability of rock mass.The linear N element of Nishihara model is replaced by a nonlinear one to conquer the model’s inability to reflect the nonlinear characteristic of the stage of accelerating creep.To consider the impact of water on rock mass mechanical properties,parameters of the model are made to be functions of water content and a P element is added to simulate hydraulic pressure mechanical affection on creep deformation,with the deformation of P element representing the deformation generated by hydraulic pressure.λis defined to quantify hydraulic pressure affection on creep deformation.Method of damage mechanics is taken to realize materials deterioration of rock mass and timeliness of creep parameters.The creep life and the ultimate strength are determined by creep test and the rest ones are determined by 1st Opt commercial software.Then the creep model is used to analyze the mining rock mass creep,with the meaningful conclusions showing that water increase the stress level of sidewall and speed up its creep rate.
出处
《应用力学学报》
CSCD
北大核心
2017年第2期377-383,共7页
Chinese Journal of Applied Mechanics
基金
西北工业大学基础研究基金(JC20110234)
关键词
含水岩体
蠕变
非线性
参数时效性
损伤力学
rock mass
water-bearing
creep
nonlinear
parameters timeliness
damage mechanics
