土石混合填料强夯过程三维离散元模拟  

Three-dimensional simulation of dynamic compaction for earth-rock fill by discrete element method

作　　者：李希 张勋 马新岩 张升[3] LI Xi;ZHANG Xun;MA Xinyan;ZHANG Sheng(School of Traffic and Transportation Engineering,Changsha University of Science and Technology,Changsha 410114,China;China Airport Construction Group Corporation,Beijing 100101,China;School of Civil Engineering,Central South University,Changsha410075,China)

机构地区：[1]长沙理工大学交通运输工程学院,长沙410114 [2]中国民航机场建设集团公司,北京100101 [3]中南大学土木工程学院,长沙410075

出　　处：《北京交通大学学报》2020年第3期88-92,108,共6页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：国家优秀青年基金(51722812);国家自然科学基金(51908066);湖南省杰出青年基金(2017JJ1033)。

摘　　要：传统强夯数值模型多针对单一类型填料,并不适用于利用强夯法加固土石混合料的情况.为此,基于PFC3D软件,首先建立了强夯颗粒流模型,通过开展强夯现场试验验证了数值模型的适用性.然后,利用建立的强夯数值模型,对夯锤位移时程特性、夯沉量发展规律及土体塑性区特征展开研究.研究结果表明,强夯过程会经历一次反弹阶段,随着夯击次数的增加反弹量增加;提出了夯沉比的修正计算方法,可以用来评价强夯单次夯击效率和确定最佳夯击次数;土体塑性区呈竖向深度大于横向的椭圆形;此次强夯最佳夯击次数为7次,有效加固深度约为3.0 m.研究结果可以为同类工程及规范的完善提供参考.The traditional dynamic compaction numerical models are mostly for a single type of fill, which is not suitable with the working condition of Dynamic Compaction(DC) for earth-rock mixture. Therefore, a particle flow model of DC is established based on PFC3 D software in this paper. Meanwhile, the numerical model is verified by DC field tests. The hammer time-displacement history, variation rule of crater depth and plastic zone characteristics are studied by DC numerical model. The results show that DC process includes a rebound stage, and the rebound increases with the number of tamping rises;A modified calculation method for crater depth ratio is proposed to evaluate the efficiency of DC single tamping and determine the optimum number of DC. The plastic zone of soil is elliptical and the vertical depth is longer than the transverse length;the optimum number of tamping is 7, the effective reinforced depth is about 3.0 m. The results obtained can provide reference for similar DC engineering and the establishment of technical standards.

关 键 词：岩土工程 强夯 离散元法 土石混合料 填方工程 

分 类 号：TU472[建筑科学—结构工程]