压实黄土变形特性  

Study of deformation characteristic of compacted loess

作　　者：陈开圣[1,2] 沙爱民[2] 

机构地区：[1]贵州大学土木建筑工程学院,贵阳550003 [2]长安大学特殊地区公路工程教育部重点实验室,西安710064

出　　处：《岩土力学》2010年第4期1023-1029,共7页Rock and Soil Mechanics

基　　金：国家西部交通建设科学研究项目(200131881212);贵州省社会发展攻关项目(黔科合SZ字[2008]3014);贵州大学引进人才项目(x065004)

摘　　要：黄土路基填料的变形特性直接关系到路基沉降和路基边坡坡度的选取,是黄土地基工程、边坡工程和洞室工程设计计算的重要参数。基于一维室内固结试验,分析了压实黄土变形特性。引入压缩变形系数,分析了压实黄土的物理指标(含水量、压实度)与变形指标(压缩变形系数、压缩系数)的关系,采用应变法来表达压缩变形曲线结果;引入非线性应力、应变关系的割线模量,研究了压实黄土的加荷本构模型和增(减)湿本构模型。结果表明:压实黄土的物理指标对其变形特性影响较大,压实黄土的应力-应变关系可以用幂函数pε=kpn的形式来表达,提出了压实黄土的加荷本构模型和增(减)湿本构模型,该模型具有较高的可靠性,为研究黄土路基沉降特性提供了有力依据。The deformation characteristic for loess subgrade filler is an important calculated parameter of loess foundation engineering, slope engineering and underground engineering because it directly related to subgrade settlement and slope angle. Based on one-dimensional consolidation tests, the deformation characteristic of compacted loess is analyzed.Introducing the concept of the compression deformation coefficient, the relation between physico indices （water content, compaction degree） and deformation indices （compression deformation coefficient, compression coefficient） is discussed, and the compression deformation curves is expressed with stress-strain method. Adopting the secant modulous parameter of nonlinear stress-strain relation, the loading constitutive model and moistening （drying） deformation model for compacted loess are studied. The results show that the physico-machanical indices of compacted loess influence greatly on the deformation characteristic. The stress-strain curves of compacted loess can be expressed with the power functionε/p=kp^n. Finally, the loading constitutive model and moistening （drying） deformation model are obtained. The reliability of the model is testified. It provides powerful reference for studying the settlement characteristics of loess subgrade.

关 键 词：压实黄土 压缩变形 割线模量 本构模型 

分 类 号：TU444[建筑科学—岩土工程]