论文部分内容阅读
水是影响岩石流变力学性质的重要因素.采用分级加载方式,对兰渝铁路木寨岭二期隧道炭质板岩开展干燥与饱水状态下的单轴蠕变试验.结果表明:饱水岩样的蠕变量和蠕变速率远大于干燥岩样的相应值,相同应力水平下的蠕变应变可达到干燥岩样的3倍以上,进入稳定蠕变阶段也需要更长的时间.分析岩石的蠕变规律,通过在Burgers流变模型上串联一个非线性粘塑性体,提出改进的非线性损伤流变模型,推导其一维和三维蠕变方程.并对流变模型参数辨识方法进行改进,采用线性递减权重粒子群算法(PSO)和Levenberg-Marqud非线性最小二乘法相结合的方法对试验结果进行参数辨识,结果表明该模型能够很好地描述炭质板岩在不同应力水平下的蠕变特性.
Water is an important factor that influences the rheological properties of rocks.Using the graded loading method, the uniaxial creep tests of carbonaceous slate in the second stage of the Muzhailing tunnel of Lanzhou-Chongqing Railway under dry and saturated conditions are carried out.The results show that: The creep amount and creep rate of rock samples are much larger than those of dry rock samples, and the creep strain at the same stress level can reach more than 3 times that of dry rock samples, and it takes longer to enter the stable creep phase. Rock creep law, a non-linear visco-plastic body is connected in series to Burgers rheological model, an improved non-linear damage rheological model is proposed and one-dimensional and three-dimensional creep equations are deduced, rheological model parameter identification method is improved, The linear regression weighted particle swarm optimization (PSO) and Levenberg-Marqud nonlinear least square method are used to identify the experimental results. The results show that the model can well describe the creep of carbonaceous slate at different stress levels Change characteristics.