生物酶改良膨胀土的动骨干曲线模型  

Dynamic backbone curve model of bioenzyme-treated expansive soil under cyclic loading

作　　者：文畅平 任睆遐[1,2] WEN Changping;REN Huanxia(School of Civil Engineering,Central South University of Forestry and Technology,Changsha 410018,China;Hunan Engineering Laboratory for Manufacturing and Application Technology of Modern Timber Structural Engineering Materials,Central South University of Forestry and Technology,Changsha 410018,China)

机构地区：[1]中南林业科技大学土木工程学院,湖南长沙410018 [2]中南林业科技大学现代木结构工程材制造及应用技术湖南省工程实验室,湖南长沙410018

出　　处：《中南大学学报（自然科学版）》2021年第4期1109-1117,共9页Journal of Central South University:Science and Technology

基　　金：国家国际科技合作专项(2014DFA53120);现代木结构工程材制造及应用技术湖南省工程实验室开放基金资助项目(HELFMTS1707);湖南省重点学科建设项目(2013ZDXK006)。

摘　　要：基于Hardin-Drnevich双曲线本构模型,研究生物酶改良膨胀土的动应力−应变关系。首先通过一系列不同生物酶掺量下的动三轴不固结不排水剪切试验,得到生物酶改良膨胀土的动骨干曲线;然后,根据三轴试验结果,分别拟合最大动弹性模量E_(dmax)、最大动应力σ_(dmax)、动骨干曲线切线变形模量E_(dt)与生物酶掺量z、围压σ_(3)的回归方程;最后,基于Hardin-Drnevich模型,建立考虑生物酶掺量影响的动骨干曲线模型以及动骨干曲线应力−应变归一化方程。研究结果表明:Hardin-Drnevich模型能很好地描述生物酶改良膨胀土的动骨干曲线双曲线特性,最大动弹性模量E_(dmax)、最大动应力σ_(dmax)、动骨干曲线切线变形模量E_(dt)等的回归方程能较好地描述其随生物酶掺量z、围压σ_(3)的变化规律;最大动弹性模量E_(dmax)、最大动应力σ_(dmax)、动骨干曲线切线变形模量E_(dt)随生物酶掺量z的增加、围压σ_(3)的增大而呈非线性增大;最大动应力σ_(dmax)可作为生物酶改良膨胀土的动骨干曲线应力−应变关系归一化因子,使动骨干曲线的线性化程度较高;引入的生物酶掺量影响因子α_(0)和α_(1)可定量反映生物酶掺量z对E_(dmax),σ_(dmax)和Edt等的影响;生物酶掺量影响因子α_(2)可定量反映生物酶掺量z对动应力σ_(d)的影响。The dynamic stress-strain properties of bioenzyme-treated expansive soil were studied based on Hardin-Drnevich hyperbola constitutive model.Firstly,a series of the dynamic triaxial unconsolidated undrained shear tests of bioenzyme-treated expansive soil at different ratios of bioenzyme-based soil stabilizer were conducted,and a series of dynamic backbone curves were obtained.Secondly,the regression expressions between the parameters such as the maximum dynamic modulus of elasticity E_(dmax),the maximum dynamic stressσ_(dmax),the tangent deformation modulus of dynamic backbone curve Edt,and the ratio of bioenzyme-based soil stabilizer z,confining pressureσ3,were fitted based on the triaxial test results respectively.Finally,a dynamic backbone curve constitutive model based on Hardin-Drnevich model,which can reflect the effect of the ratio of bioenzyme-based soil stabilizer z on the dynamic stress-strain property of bioenzyme-treated expansive soil,was proposed.The results show that Hardin-Drnevich model can better describe the hyperbola characteristics of dynamic backbone curves of bioenzyme-treated expansive soil,and the regression equations can better reflect the influences of the ratio of bioenzyme-based soil stabilizer z and confining pressureσ3 on E_(dmax),σ_(dmax),and Edt.The maximum dynamic modulus of elasticity E_(dmax),the maximum dynamic stressσ_(dmax),and the tangent deformation modulus of dynamic backbone curve Edt increase nonlinearly with the increase of the ratio of bioenzyme-based soil stabilizer z and confining pressureσ3.The maximum dynamic stressσ_(dmax)can be adopted as the normalized factor in the normalization analysis of dynamic stress-strain relation of bioenzyme-treated expansive soil,and it can normalize the dynamic stress-strain relationship of dynamic backbone curves much better.The introduced factorα0 andα1 can quantitatively reflect the influences of the ratio of bioenzyme-based soil stabilizer z on E_(dmax),σ_(dmax)and Edt,respectively,and the introduced factorα2 can quant

关 键 词：生物酶改良膨胀土 动骨干曲线模型 动应力−应变关系 动三轴试验 

分 类 号：U416.1[交通运输工程—道路与铁道工程]