花岗岩非定常蠕变及其参数确定  

Study on Non-stationary Creep and Parameter Determination of Granite

作　　者：张树光[1] 刘文博[1] 王有涛[1] 

机构地区：[1]辽宁工程技术大学土木与交通学院,辽宁阜新123000

出　　处：《防灾减灾工程学报》2017年第3期435-441,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：国家自然科学基金项目(51274109)资助

摘　　要：深部岩体工程的长期稳定性与围岩的时效变形特性有着紧密的联系,花岗岩在高地应力作用下会呈现出流变特性,采用TAW-2000岩石三轴试验机,对花岗岩试件在三轴压缩条件下进行了蠕变特性试验。通过德鲁克-普拉格屈服函数在西原体一维蠕变方程中引入强度参数C、φ值,推导出三维状态下轴向蠕变方程来描述花岗岩蠕变过程,并分析了变形参数泊松比和强度参数C、φ的变化规律。由三轴试验结果,用非线性最小二乘法求出了不同围压作用不同时刻下的流变参数,并根据参数分布规律得到了流变参数与应力和时间的关系,最后推出非定常三维非线性蠕变方程。研究表明:该模型能很好反映花岗岩流变参数随应力和时间的弱化规律、稳定蠕变和衰减蠕变过程的蠕变特性,为深部岩石工程的长期稳定性问题提供新的研究思路与研究方法。The long-term stability of rock mass engineering in deep stratum rock engineering are closely related to the aging deformation characteristics.Hard rock under the conditions of high geo-stresses presents obviously rheological property.Triaxial rheological tests under different stress paths were carried out on TAW-2000 rock machine.By using the Drucker-Prager yield function we introduce the strength parameters C,φvalue to the Nishihara model one-dimensional creep equation,derived three-dimensional creep equation to describe the creep process of granite,and analyze the change law of deformation parameters of Poisson＇s ratio and strength parameters Candφ.According to the triaxial rheological tests results,the rheological parameters of different confining pressures are obtained by nonlinear least square,and according to the distribution law of the parameters we get the relationship between rheological parameters and stress and time.Finally,the model can be used to study the creep properties of granite.The results show that the model can closely reflect the creep characteristics of the rheological parameters of granite and the weakening of rheological parameters with stress and time,and the results provide new research ideas and research methods for the long-term stability of rock mass engineering in deep stratum rock engineering.

关 键 词：流变参数 长期强度 屈服条件 最小二乘法 

分 类 号：TU458[建筑科学—岩土工程]