基于扰动状态理论的生物酶改良膨胀土K-G模型  

K-G Model of Bioenzyme-treated Expansive Soil Based on Disturbed State Theory

作　　者：文畅平[1,2] WEN Chang-ping1,2(1. Hunan Engineering Laboratory for Manufacturing and Application Technology of Modern Timber Structure Engineering Material, Central South University of Forestry and Technology, Changsha 410018, Hunan, China; 2. School of Civil Engineering, Central South University of Forestry and Technology, Changsha 410018, Hunan, Chin)

机构地区：[1]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 [2]中南林业科技大学土木工程学院,湖南长沙410018

出　　处：《中国公路学报》2018年第2期308-318,共11页China Journal of Highway and Transport

基　　金：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项目(HELFMTS1707);湖南省重点学科建设项目(2013ZDXK006)

摘　　要：以生物酶改良膨胀土的非线性弹性本构关系为研究对象,提出基于扰动状态理论的修正KG模型。首先开展不同生物酶掺量条件下的重塑膨胀土样的等向固结排水试验和等p三轴固结排水剪切试验,研究生物酶改良膨胀土的应力-应变关系特征,基于非线性弹性K-G模型,分析生物酶掺量对膨胀土的切线体积模量Kt和切线剪切模量Gt中相关参数的影响规律。采用生物酶掺量作为扰动掺量,以试验和扰动状态概念为基础建立扰动函数,基于扰动状态理论对K-G模型进行修正,以反映生物酶掺量对改良膨胀土应力-应变扰动关系,使本构关系符合土体的实际变形过程,更合理地描述生物酶改良膨胀土的非线性弹性应力-应变关系。结果表明:通过对比εv-p及εs-q的试验曲线、K-G模型曲线与修正K-G模型理论计算曲线,体应变εv的K-G模型预测值小于试验值,而剪应变εs的K-G模型预测值大于试验值,修正K-G模型的体应变εv和剪应变εs的预测值都与试验值较为接近。修正K-G本构模型中各参数物理意义明确,与K-G模型中的参数确定方法一致,可以较合理地描述不同生物酶掺量扰动条件下改良膨胀土的变形特性。A modified K-G model based on disturbed state theory （DST） was proposed to investigate the nonlinear elastic constitutive relation of bioenzyme-treated expansive soil. The isotropic consolidation drainage tests and triaxial consolidated drained shear tests with constant p of remolded expansive soil samples under different ratios of bioenzyme were conducted, and the stress-strain relationship of bioenzyme-treated expansive soil was investigated. The influence mechanism of the ratio of bioenzyme on the tangent bulk modulus Kt and tangent shear modulus Gt of expansive soil was analyzed based on nonlinear K-G model. In order to accord with the actual deformation process, and describe the nonlinear stress-strain relationship of bioenzymetreated expansive soil more reasonably, based on tests and DST, the disturbance function was defined by taking the ratio of bioenzyme as a disturbance parameter, and a modified K-G model based on DST was put forward to reflect the disturbed effects of the ratio of bioenzyme on the stress-strain relationship of bioenzyme-treated expansive soil. The results show that, according to the comparison among experimental curves, K-G model curves and modified K-G model curves of εv-p and εs-q, the predicted value of bulk strain εv by K-G model is smaller than the test value, whilst the predicted value of shear strain εs is larger than the test value. Both the predicted values of bulk strain εv and the shear strain εs by modified K-G model agree well with the test values respectively. The physical meaning of all kinds of parameters of the modified K-G models clear, and the test methods for determining the parameters in the modified K-G model are the same as that in the K-G model. The deformation characteristics of expansive soil under the different ratio of bioenzyme-based soil stabilizer can be reasonably described by the modified K-G model.

关 键 词：道路工程 生物酶改良膨胀土 非线性K-G模型 扰动状态理论 

分 类 号：U416.1[交通运输工程—道路与铁道工程]