注浆渗透扩散的多物理场耦合数值分析  

Numerical Analysis of Multiphysics Coupling of Grout Penetration

作　　者：陈锋 杨杰 张冲 余祯[3,4] 刘先峰 CHEN Feng;YANG Jie;ZHANG Chong;YU Zhen;LIU Xianfeng(China Academy of Railway Sciences Co.,Ltd.,Beijing 100081,China;Faculty of Construction and Environment,The Hong Kong Polytechnic University,Hong Kong 999077,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Key Laboratory of High-Speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Xinjiang Institute of Engineering,Urumqi 830023,China)

机构地区：[1]中国铁道科学研究院集团有限公司,北京100081 [2]香港理工大学建设及环境学院,中国香港999077 [3]西南交通大学土木工程学院,四川成都610031 [4]西南交通大学高速铁路线路工程教育部重点工程实验室,四川成都610031 [5]新疆工程学院土木工程学院,新疆乌鲁木齐830023

出　　处：《西南交通大学学报》2024年第6期1469-1478,共10页Journal of Southwest Jiaotong University

基　　金：中国铁道科学研究院基金项目(2020YJ105)。

摘　　要：非饱和地层中的注浆渗透扩散是一个复杂的多物理场过程,为更加精确分析浆液在饱和与非饱和地层中的扩散特性,并估算注浆渗透扩散范围和注浆挤密区域,以混合理论为基础,建立一个非饱和多孔介质中的多物理场耦合模型.通过ABAQUS二次开发,构建一种新型八节点五自由度四边形轴对称Serendipity单元,实现对注浆过程中土体变形、土体孔隙率、孔隙压力和浆液浓度分布的数值求解,以及对土体饱和度、渗透系数等状态变量的实时更新;结合一个三维轴对称注浆算例,分析浆液水灰比、注浆压力、土体初始干密度以及土体初始含水率对粉砂地层注浆效果的影响,并得到浆液水平和竖向扩散距离随不同因素变化的拟合曲线.研究结果表明:浆液扩散范围受水灰比影响最显著,受注浆压力影响次之,受含水率和干密度影响最小;浆液扩散范围随水灰比增加而增长,水灰比大于1.0时增长显著;注浆管壁周围会形成挤密区域,浆液扩散区域内土体同时受到注浆压力的挤压和孔隙压力的支撑作用;随着远离注浆管壁,土体孔隙率在挤密区域内逐渐减小,在挤密区域外逐渐恢复,且挤密区域随注浆压力的增加而增大;研究成果可为土体注浆加固范围计算提供理论指导.Grout penetration in the unsaturated formation is a complex multiphysics process.In order to analyze more accurately the penetration characteristics of grout in saturated and unsaturated formations and estimate the range of grout penetration and grout compaction area,a multiphysics coupling model for unsaturated porous media was developed based on mixture theory.A novel five-degree-of-freedom eight-node quadrilateral axisymmetric Serendipity element was constructed through the secondary development of ABAQUS,so as to realize the numerical solution of soil deformation,soil porosity,pore pressure,and grout concentration distribution during grouting.The state variables,such as soil saturation and permeability coefficient,were updated in real time.The effects of grout water-cement ratio,grouting pressure,initial dry density,and water content of soil on the grouting in silty sand were analyzed with a three-dimensional axisymmetric grouting example,and the fitting curves of horizontal and vertical diffusion distance of grout with the above factors were obtained. The results show that the range of grout penetration is most significantly influenced by the water-cement ratio, followed by the grouting pressure, and it is least influenced by the water content and dry density of soil;the range of grout penetration increases with the increase in the water-cement ratio, especially when the water-cement ratio is greater than 1.0;a compacted area will be formed around the grouting pipe, where the soil is simultaneously subject to the grouting pressure and pore pressure;with the increase in the distance from the grouting pipe, the porosity of the soil gradually decreases in the compacted area and gradually recovers outside the compacted area, while the compacted area increases with the increase in the grouting pressure. The research results can provide theoretical guidance for calculating the grouting reinforcement in the soil.

关 键 词：注浆渗透 多物理场 有限元方法 非饱和土 

分 类 号：O242.2[理学—计算数学]