红层泥岩剪切蠕变特性及非定常本构模型研究  

Shear creep properties and its unsteady constitutive model of the red mudstone

作　　者：李宁[1] 张慧莉 张茂建 江宇 樊勇 沐红元 LI Ning;ZHANG Huili;ZHANG Maojian;JIANG Yu;FAN Yong;MU Hongyuan(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China;College of Civil Engineering,Tongji University,Shanghai 200092,China;Yunnan Institute of Water&Hydropower Engineering Investigation,Design&Research,Kunming 650021,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]同济大学土木工程学院,上海200092 [3]云南省水利水电勘测设计研究院,昆明650021

出　　处：《上海理工大学学报》2023年第6期626-635,共10页Journal of University of Shanghai For Science and Technology

基　　金：国家自然科学基金资助项目(40872179,U1765110);上海市自然科学基金资助项目(16ZR1423300)。

摘　　要：滇中红层泥岩具有显著的流变特性,会给当地工程建设带来安全隐患。选取狮子山隧洞段的红层泥岩进行分级加载蠕变试验,对其蠕变特性开展研究。结果表明,在较低应力状态下,岩样主要表现为衰减蠕变,而在较高应力状态下,岩样将发生从衰减蠕变、等速蠕变直至加速蠕变破坏的全过程蠕变。对岩样各阶段变形数据进行回归分析,建立拟合方程,发现岩样各阶段变形具有显著的非线性变形特性。根据岩样的非线性变形特性提出了1个指数型加速元件,通过与Bingham体中的黏性元件串联形成改进的Bingham体,使其能克服传统Bingham体模拟加速阶段存在的不足,并同时对Hoek体及Kelvin体进行非线性改进,然后通过将非线性Hoek体、Kelvin体与改进Bingham体串联,建立了1个能够描述滇中红层泥岩蠕变特性的非线性、非定常黏弹塑性岩石蠕变模型。通过与不同剪应力下红层泥岩的蠕变试验曲线进行比较,发现理论模型得到的结果与试验数据吻合较好,表明所建模型对于滇中红层泥岩具有较好的适用性。Red mudstone in central Yunnan has significant rheology properties,which can bring hazards to the engineering construction.Using step loading shear creep experiments,the shear creep characteristics of the red mudstone,which from ShiziShan tunnel section,were investigated.The results showed that,the rock samples mainly exhibited decay creep at smaller stresses,while it would undergo the whole process of creep from decay creep,steady creep to accelerate creep damage at larger stresses.Regression analysis was conducted on the deformation data of each stage of the rock sample,and a fitting equation was established,and it was found that the deformation of rock samples at each stage was nonlinear.In accordance with the nonlinear deformation properties of the rock sample,an exponential acceleration element was proposed.By connecting with the viscous element in the Bingham body,a modified Bingham body was formed.It can overcome the shortcomings in acceleration phase simulation of the traditional Bingham body.Additionally,the nonlinear improvements were made to the Hoke and Kelvin body.By series connecting the nonlinear Hoek body,Kelvin body and the modified Bingham body,a nonlinear and unsteady viscoelastic-plastic rock creep model,which can describe the creep characteristics of the red mudstone in central Yunnan,was established.The results from the theoretical model were in good agreement with the experimental data,indicating that the proposed model was reasonable.

关 键 词：红层泥岩 剪切蠕变试验 非线性加速元件 改进Bingham体 非线性 非定常本构模型 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]