【作者】 周玉锋；

【导师】 郑健龙；

【作者基本信息】 长沙理工大学 ， 道路与铁道工程， 2005， 硕士

【摘要】 膨胀土问题是工程地质和非饱和土力学领域中最为复杂的研究难题之一。目前关于膨胀土的膨胀变形和膨胀本构关系的研究已相对较多,但绝大多数都是建立在充分膨胀的基础上,且得出的规律基本是在初始含水量不变条件下,膨胀变形量与上覆压力的单一关系和在上覆压力不变条件下,膨胀变形量与初始含水量的单一关系。膨胀土的膨胀机理复杂,影响膨胀变形量的因素繁多,找出其中的主要因素,建立合理准确、膨胀本构关系是膨胀变形研究的关键。本文在前人研究的基础上,通过大量的室内试验研究,分析探讨了广西宁明膨胀土有荷膨胀量与上覆荷载的关系、有荷膨胀量与初始含水量的关系、无荷膨胀量和初始含水量的关系以及膨胀力与初始含水量的关系,提出了广西宁明膨胀土确定干密度下的有荷膨胀量与初始含水量和上覆压力的关系式,可以用来计算在初始含水量和上覆压力同时变化时下的有荷膨胀量;同时分析了有荷膨胀量试验中终了含水量与上覆压力和初始含水量的关系,得到了确定干密度下的终了含水量与初始含水量和上覆压力的关系式;本文还分析了过程膨胀变形量和过程含水量成线性关系,根据此条件和终了含水量的关系式以及有荷膨胀量的关系式可以得到某一过程含水量下的有荷膨胀量。　在此试验的基础上,推导出一维关系下宁明膨胀土的切线模量和初始割线模量和三维关系下此膨胀土的变形模量和体积模量。更多还原

【Abstract】 The dilational srtain of expansive soils is one of the most difficult problem in the field of engineering geology and unsaturated soils mechanics. At present,many tests on dilatationgal strain and research on swelling constitutive relationships have been carried out. However the overwhelming majority is based on plenteous water supply, and law drawn is all about wether the initial water content is constant, the single relationship between the swelling strains and vertical pressure,or when the vertical pressure is constant, the single relationship between the swelling strains and initial water content. The swelling mechanism of expansive soils is complicated ,to find out the major factor and to establish reasonable and accurate swelling constitutive relationship is the key to expansive soils. Based on the laboratory swelling experiments, relationship between the swelling strain under load and the vertical pressure、relationship between the swelling strain under load and initial water content 、relationship between the swelling strain under free load and initial water content and relationship between the swelling pressure and initial water content are systematically studied in this thesis,and put forward to a swelling prediction formula which can be used to calculate the swelling strain under load when the initial water content and the vertical pressure vary at the same time;the relationship between the final water content and initial water content ,the relationship between the final water content and vertical pressure is also presented, and bring forward a formula which can be used to calculate the final water content;additional, that the relationship between the swelling process strain under load and process water content is linear is also verified. Based on the laboratory swelling experiments results, the additional compression modulus、the initial tangent modulus in 1D 、deformation modulus and volume deformation modulus in 3D of expansive soils in Ning-Ming are formulated.更多还原