巴东组泥岩非线性流变本构模型研究  

Study on creep constitutive model of Badong formation mudstone under triaxial creep test

作　　者：王闫超[1,2] 晏鄂川 丛璐[3] 张军 邱敏[4] 孙志杰 张川川[2] 张蕾 WANG Yanchao;YAN Echuan;CONG Lu;ZHANG Jun;QIU Min;SUN Zhijie;ZHANG Chuanchuan;ZHANG Lei(Faculty of Engineering,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China;Transportation Industry Key Laboratory of Highway Construction and Maintenance Technology in Loess Area,Shanxi Transportation Research Institute,Taiyuan,Shanxi 030006,China;Department of Civil Engineering,Shanxi University,Taiyuan,Shanxi 030006,China;National Enterprise Technology Center,CCC Second Harbour Engineering Co.,Ltd.,Wuhan,Hubei 430040,China)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074 [2]山西省交通科学研究院黄土地区公路建设与养护技术国家交通行业重点实验室,山西太原030006 [3]山西大学土木工程系,山西太原030006 [4]中交第二航务工程局有限公司技术中心,湖北武汉430040

出　　处：《岩石力学与工程学报》2019年第S02期3362-3373,共12页Chinese Journal of Rock Mechanics and Engineering

基　　金：山西省交通厅科技项目(2018-1-33);山西交控集团科技项目(18-JKKJ-04,18-JKKJ-08)。

摘　　要：巴东组泥岩是红层软岩的一种,是典型的易滑地层,因此研究巴东组泥岩的力学特性有着十分重要的意义。本文以巴东组泥岩为研究对象,开展室内瞬时力学试验和流变力学试验。根据巴东组泥岩瞬时三轴压缩试验结果确定流变试验应力加载等级,开展三轴压缩条件下巴东组泥岩流变力学试验,分析岩石的流变力学特性。通过比较屈服强度与流变长期强度,引入屈服应力阈值元件和长期强度阈值元件;研究破坏阶段的黏滞系数变化规律,采用幂函数描述破坏阶段的黏滞系数特征,引入具有应变阈值的非线性牛顿体元件。最终建立一个新的八元件非线性黏弹塑性流变本构模型。应用L-M算法对流变试验曲线进行辨识,得到各个加载等级水平下的流变模型参数。对比试验数据与模型拟合数据,两者吻合较好,表明本文建立的流变本构模型能够准确的描述岩石的3个典型流变阶段。最后分析了应变阈值元件参数和应变阈值对流变时长的约束作用。Many dipping translational rock slides occurred in purple mudstone of Badong formation of Triassicstrata(T2b^4) in western Hubei Province and eastern Chongqing City. In order to research the mechanism of theserock slides, a series of conventional triaxial tests and triaxial creep tests for mudstone from the strata wereperformed, and rock creep mechanical properties were obtained. By comparing the yield stresses from theconventional triaxial test and the long-term strength from triaxial creep test, an element with yield stress thresholdswitch and an element with long-term strength switch were proposed. The pattern of viscous coefficient could befitted by the power function satisfactorily and a nonlinear Newtonian element was proposed. Finally, a new nonlinear constitutive creep model with eight elements was established. The experimental data at all stages ofcreep could be fitted by the new model very well and the model parameters were obtained successfully. At last,parameters sensitivity studies for the analytical solution of the proposed model was carried out and the resultsindicated that the parameters of nonlinear Newtonian element and creep threshold value could affect the creeptime significantly.

关 键 词：岩石力学 巴东组泥岩 流变试验 流变本构模型 参数敏感性分析 

分 类 号：TU45[建筑科学—岩土工程]