考虑固化剂掺量影响的镁质水泥固化土非线性本构模型  

A nonlinear constitutive model for soft clay stabilized by magnesia cement considering the effect of solidified agent content

作　　者：朱剑锋 徐日庆[3,4] 罗战友 潘斌杰 饶春义[5] ZHU Jian-feng;XU Ri-qing;LUO Zhan-you;PAN Bin-jie;RAO Chun-yi(School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou,Zhejiang 310023,China;Institute of Tunnel and Underground Space,Zhejiang University of Science and Technology,Hangzhou,Zhejiang 310023,China;Research Center of Coastal and Urban Geotechnical Engineering,Zhejiang University,Hangzhou,Zhejiang 310058,China;Zhejiang-California International Nano Systems Institute Taizhou Branch,Taizhou,Zhejiang 318000,China;School of Civil Environmental Engineering,Ningbo University,Ningbo,Zhejiang 315211,China)

机构地区：[1]浙江科技学院土木与建筑工程学院,浙江杭州310023 [2]浙江科技学院隧道与地下空间技术开发研究院,浙江杭州310023 [3]浙江大学滨海和城市岩土工程研究中心,浙江杭州310058 [4]浙江加州国际纳米技术研究院台州分院,浙江台州318000 [5]宁波大学土木与环境工程学院,浙江宁波315211

出　　处：《岩土力学》2020年第7期2224-2232,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51879133,No.51409142,No.41672264);浙江省自然科学基金(No.LY17E080006)。

摘　　要：为准确描述不同固化剂掺量Wg下镁质水泥固化土的力学特性,通过开展不同W_g下固化土的室内试验,提出了镁质水泥固化土的非线性本构模型。采用新型环保的镁质水泥复合固化剂加固淤泥,并对不同Wg下的镁质水泥固化土进行扫描电镜(SEM)试验、一维压缩试验和不排水三轴试验。结果发现:镁质水泥固化土具有显著的结构性,且随着Wg的增加,结构屈服应力越大,水化产生的胶凝材料增加了土颗粒间的黏结力,水化产物逐渐填充土体孔隙,镁质水泥固化土的应力-应变曲线由加工硬化型逐渐转变为加工软化型。根据试验结果,提出了一个能涵盖固化剂掺量影响并能实现应力-应变关系转型的镁质水泥固化土本构模型。算例验证该本构模型预测结果与试验结果比较吻合,能较好预测任意Wg下镁质水泥固化土的应力-应变关系。This study aims to develop a nonlinear constitutive model to address the mechanical properties of magnesia-cementsolidified soil under different contents of solidified agent(Wg)on the basis of the results of a series of laboratory tests.Firstly,a new type of environmentally magnesia cement composite curing agent was adopted to solidify the sludge.Then,the scanning electron microscope(SEM)tests,the one-dimensional consolidation tests and the undrained triaxial tests were carried out on the magnesia cement solidified soil with different contents of W_g.The test results show that there exists a strong structure in the inner of the magnesia-cement-solidified soil and the associated structural yield stress becomes larger and larger with the increase of Wg.The cohesion between the soil particles increased due to the binding material produced by the hydration reaction,which produces the material to fill the soil void.As such,the stress-strain behaviour of the magnesia-cement-solidified soil transformed from work hardening to work softening.Based on the aforementioned test results,a constitutive model was developed to investigate the transformation of the stress-strain relationship of the magnesia-cement-solidified soil,in which the effect of solidified agent content(Wg)could be also accounted for.The numerical examples show that the proposed constitutive model behaves well in predicting the stress-strain behaviour of the magnesia-cement-solidified soil at any amount of Wg.

关 键 词：镁质水泥 固化土 掺量 扫描电镜 结构屈服应力 加工硬化 加工软化 非线性 本构模型 

分 类 号：TU472[建筑科学—结构工程]