考虑颗粒破碎影响的粗粒土本构模型  

Constitutive model for coarse granular aggregates incorporating particle breakage

作　　者：贾宇峰[1] 迟世春[1] 林皋[1] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,大连116024

出　　处：《岩土力学》2009年第11期3261-3266,3272,共7页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.50479057)

摘　　要：颗粒破碎直接改变了粗粒土本身结构,对粗粒土的剪胀、内摩擦角、峰值强度、渗透系数都会产生影响。为了能够准确地描述粗粒土的应力-应变关系,特别是高应力条件下出现显著颗粒破碎时的应力-应变关系,亟待建立考虑颗粒破碎的粗粒土本构模型。根据三轴试验数据,建立考虑颗粒破碎耗能的应力-应变关系,采用相关联流动法则导出考虑颗粒破碎的粗粒土本构模型。所建立的本构模型考虑了颗粒破碎对粗粒土剪胀、内摩擦角的影响。通过变异粒子群优化算法确定模型参数,拟合试验曲线。模型计算结果与试验曲线拟合较好,能够很好地描述粗粒土在不同围压下的体积剪胀、剪缩和应力硬化、软化现象。Particle breakage of coarse granular aggregates modifies its structure directly, influencing its dilatancy, friction angle, strength and permeability. In order to accurately describe stress-strain relationship of coarse granular aggregates, especially in high pressure with significant particle breakage, it is indispensable to develop coarse granular aggregates constitutive model incorporating particle breakage. According to triaxial test results, the stress-strain relationship incorporating particle breakage is developed, on which a constitutive model is generated incorporating particle breakage with application of associated flow rules. The constitutive model incorporates the influences exerting on dilatancy and friction angle by particle breakage. The parameters of model are determined by mutation particle swarm optimization algorithm, on which the stress-strain curves of triaxial test are simulated. The simulation of model presentation and test results accurately describe dilation and contraction, strain hardening and post-peak strain softening features of the coarse aggregates at various confining pressures.

关 键 词：颗粒破碎 破碎耗能 应力软化 变异粒子群优化算法 摩擦系数 临界状态线 剪胀 

分 类 号：TU411[建筑科学—岩土工程]