基于能量方法的结构性土体损伤演化规律研究  

Damage evolution of structured soil based on energy method

作　　者：周家伍[1,2,3] 刘元雪[1,2] 李忠友[1,2] 

机构地区：[1]后勤工程学院土木工程系,重庆401311 [2]岩土力学与地质环境保护重庆市重点实验室,重庆401311 [3]空军第六空防工程处,湖南衡阳421001

出　　处：《岩土工程学报》2013年第9期1689-1695,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50979112);重庆市自然科学基金项目(CSTC;2008BB6144)

摘　　要：结构性土体的力学特性具有明显的损伤破损效应。根据岩土材料复合体损伤理论,结构性土体可看作是由结构相和损伤相各占一定比例的复合材料。结构性土体的损伤过程本质上是土体中结构相的变形能向相变损伤耗散能转化,相变损伤耗散能促使结构相退变为损伤相的损伤发展过程。从任意方向截面上看,结构相表面损伤后即变为损伤相的表面。基于此认识,把结构性土体的损伤变量与结构相、损伤相所占的截面面积联系起来,从而与经典连续介质损伤力学中关于损伤变量的定义一致。将土体结构的损伤引起的外力多做的那部分功定义为相变损伤耗散能,并将此引入到土体的能量平衡方程中。通过对结构性土代表体元的能量分析,推导了基于结构损伤耗能条件下的损伤演化方程,给出了模型参数的确定方法。最后将试验结果和本文方法的结果进行对比,表明本文方法能较好反映土体损伤演化规律。The mechanical response of structured soil has obvious damage effects.According to the theory of complex for geotechnical materials,structured soil can be considered as the composite material constituted by the structured phase and the damaded phase.Structured soil damage process should be the deformation energy in the structural phase transiting to the dissipated energy of damage,and damage dissipative of phase change induce structural phase change to the damage phase.Viewing from a cross-section in any direction,damage resulting in the surface of structured phase into damage one.Based on this understanding,the damage variable is linking to cross-section areas of structured phase and damage phase is consistent with that of the damage variable in the classical continuum damage mechanics.The external force damage power is defined as damage dissipation energy,and introduced into the soil energy balance equation.For a typical unit of energy,a damage evolution equation is derived based on the energy consumption under the conditions of structural damage,and the determination method is provided for the model parameters.Finally,the comparison of test results and that of this model show that the proposed model can reflect the evolution of soil damage properly.

关 键 词：土体 本构关系 损伤演化方程 结构性 

分 类 号：TU43[建筑科学—岩土工程]