基于变蠕变参数的巷道围岩蠕变模型研究
Research on Creep Model of Roadway Surrounding Rock Based on Variable Creep Parameters
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摘要: 为了研究四川华蓥煤矿巷道围岩在不同围压特性条件下的蠕变特性,采用TAW-2000试验系统对砂岩进行三轴蠕变试验。以改进的西原模型为基础,通过引入损伤变量与时间的关系,对模型蠕变参数进行非定常化,得到改进后的变参数蠕变时效性模型。结果表明:建立的变参数时效性蠕变模型不仅可以描述岩石衰减蠕变和稳定蠕变变形特性,也弥补了传统蠕变模型无法描述加速蠕变特性的缺点,且很好地预测蠕变变形发展规律;模型与试验曲线良好吻合度,说明了该模型的正确性与合理性。Abstract: In order to study the creep behavior of surrounding rock of Huaying Coal Mine in Sichuan under different confining pressure characteristics, the triaxial creep test of sandstone was carried out by TAW-2000 test system. Based on the improved Nishihara model, the model creep parameters are denormalized by introducing the relationship between damage variables and time. The improved variable parameter creep aging model is obtained. The results show that the time-dependent creep model with variable parameters can not only describe the attenuation creep and stable creep deformation characteristics of rocks, but also make up for the shortcomings that traditional creep models cannot describe accelerated creep characteristics. And it predicts the development of creep deformation well. The good agreement between the model and the test curve illustrates the correctness and rationality of the model.