双向激振液化的离散颗粒-流体耦合模拟方法  

Study on liquefaction simulation of coupled particle-fluid assembly subject to bi-directional cyclic loading

作　　者：金炜枫[1] 张力友[1] 陈小亮[2,3,4] 程泽海[1] 

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]浙江大学建筑工程学院,浙江杭州310058 [3]浙江大学滨海和城市岩土工程研究中心,浙江杭州310023 [4]杭州市市政工程集团有限公司,浙江杭州310023

出　　处：《浙江大学学报（工学版）》2016年第11期2135-2142,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51408547);浙江省自然科学基金资助项目(LQ14E080009)

摘　　要：针对离散元模拟动三轴液化时难以施加围压,导致无法实现双向激振液化模拟的问题,提出引入适用的流体方程和有效的伺服围压算法实现动围压加载.针对流体方程,采用包含适用于流体边界网格移动的任意拉格朗日-欧拉描述(ALE)项和流体-颗粒耦合力项的流体方程组;针对伺服围压算法,将离散颗粒-流体伺服体系等效为弹簧-振子模型,采用的围压伺服力函数基于自动控制理论中的HJB方程得到.将流体有限元方程和伺服围压算法嵌入颗粒流软件(PFC2D),通过模拟双向动三轴液化实验,结果表明,该方法可以有效施加动围压,实现双向激振液化的离散颗粒-流体耦合模拟.For particle-based simulation of liquefaction, it was difficult to apply cell pressure to the particle assembly during dynamic tri-axial test, which resulted in the unaccomplishment of liquefaction simulation under bi-directional loads. Appropriate dynamic fluid equations and effective cell-pressure servo-control method were introduced in order to apply dynamic cell pressure. As for fluid equations, they were based on arbitrary Lagrangian-Eulerian description and involved coupled fluid-particle terms. As for servo-control method of cell-pressure, the optimal feedback control function of controlling cell-pressure was obtained from the Hamilton-Jacobian-Bellman （HJB） Equation established from the spring-mass model by simulating the particle assembly and the servo wall as a spring-mass model. Then coupled fluid-particle based simulation of liquefaction under bi-directional loads during dynamic tri-axial test was realized by adding finite element fluid equations and the servo-control method to the discrete element method software particle flow code 2D （PFC2D）, The method can well apply dynamic cell pressure and accomplish coupled particle-fluid based simulation of liquefaction under bi-directional loads.

关 键 词：双向激振 液化 流体边界移动 细观颗粒 

分 类 号：TU435[建筑科学—岩土工程]