粉砂质泥岩蠕变特性与非线性黏弹塑性本构模型  

Creep characteristics of silty mudstone and nonlinear viscoelastic-plasticity constitutive model

作　　者：付宏渊[1,2] 戚双星 史振宁[2,3] 高乾丰 匡波 曾铃[1] FU Hongyuan;QI Shuangxing;SHI Zhenning;GAO Qianfeng;KUANG Bo;ZENG Ling(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,P.R.China;National Engineering Laboratory of Highway Maintenance Technology,Changsha University of Science&Technology,Changsha 410114,P.R.China;School of Traffic&Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,P.R.China;Guangxi Communications Design Group Co.,Ltd.,Nanning 530029,P.R.China)

机构地区：[1]长沙理工大学土木工程学院,长沙410114 [2]长沙理工大学公路养护技术国家工程实验室,长沙410114 [3]长沙理工大学交通运输工程学院,长沙410114 [4]广西交通设计集团有限公司,南宁530029

出　　处：《土木与环境工程学报（中英文）》2024年第3期1-8,共8页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51838001、51908069、52078066、52078067);湖湘青年科技创新人才项目(2020RC306);湖南省重点领域研发项目(2019SK2171);长沙市杰出创新青年培养计划(kq1905043);国家级大学生创新创业训练项目(202120536003);长沙理工大学公路养护技术国家工程实验室开放基金(kfj170103)。

摘　　要：针对边坡、隧道工程中粉砂质泥岩长期稳定性问题,采用DZSZ-150型多场耦合岩石三轴压力试验机,利用粉砂质泥岩相似材料试样,开展不同围压下粉砂质泥岩蠕变试验。根据蠕变试验结果建立可描述粉砂质泥岩蠕变全过程的非线性黏弹塑性本构模型,以7 MPa围压下蠕变试验结果为例,对所提出的蠕变本构模型进行合理性和可行性验证。结果表明:试样的稳态蠕变速率与偏应力大小有关,随着偏应力的增加,试样稳态蠕变速率与偏应力之间符合指数函数关系;在加速蠕变阶段的蠕变速率相对低偏应力水平下减速蠕变和稳态蠕变速率明显要增大很多,且非常短时间内就发生了蠕变破坏;提出一种描述粉砂质泥岩全蠕变过程的非线性黏弹塑性本构模型,该模型能描述粉砂质泥岩蠕变-破坏全过程的蠕变变形规律,反映了粉砂质泥岩在不同偏应力水平作用下的蠕变特性,克服了经典模型中无法准确描述加速蠕变过程的难题。In order to guarantee the long-term stability of silty mudstone in slope and tunneling projects,the DZSZ-150 multi-field coupling rock triaxial pressure testing machine was used to conduct creep tests on silty mudstone specimens of similar materials under different surrounding pressures.Based on the testing results,a nonlinear viscoelastic-plastic constitutive model describing the whole creep process of silty mudstone was established,and the proposed creep model was verified for its rationality and feasibility by taking the results at a confining pressure of 7 MPa as an example.It show that the steady-state creep rate of the specimen is related to the magnitude of the deviatoric stress,and with increase of the deviatoric stress,the steady-state creep rate and the deviatoric stress conform to an exponential function relationship;the creep rate in the accelerated creep stage is significantly greater than that in the decelerated creep and steady-state creep at low stress levels,and the creep damage occurs in a very short time;a nonlinear viscoelastic-plastic constitutive model is proposed to describe the whole creep process of the silty mudstone,which can describe the creep-deformation law of the whole process of creep-damage of silty mudstone,reflecting the creep characteristics of silty mudstone under different levels of deviatoric stress,and avoiding the problem that the classical model cannot accurately describe the accelerated creep process.

关 键 词：粉砂质泥岩 蠕变试验 加速蠕变 蠕变特性 本构模型 

分 类 号：TU411.6[建筑科学—岩土工程]