考虑泊松效应的流泥轴对称真空过滤理论  

Radial filtration model for prefabricated vertical drain treatment of slurry considering Poisson’s effects

作　　者：蔡袁强[1] 叶晓倩 史吏 CAI Yuanqiang;YE Xiaoqian;SHI Li(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310014,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州310014

出　　处：《岩土工程学报》2025年第2期243-254,共12页Chinese Journal of Geotechnical Engineering

基　　金：离岸岛群深厚软土地基交通基础设施建设关键技术(2023YFB2604200);国家自然科学基金项目(52278377,U2006225);浙江省自然科学基金项目(LZ22E080009)。

摘　　要：真空预压处理流泥地基时,仅排水板附近的土体得到明显加固,以排水板为轴线形成一个凸出地表的“土柱”。土柱作为流泥地基真空预压处理的特有现象,导致流泥地基淤堵严重、处理效果差。根据流泥固液两相的连续、运动、平衡以及土柱移动边界方程,并考虑土柱土体泊松效应,在柱坐标系下建立了流泥轴对称真空过滤模型,获得了流泥地基真空预压过程中的土柱生长规律和土柱淤堵性状,并与PIV试验进行了对比验证。结果表明:土柱内渗透系数降幅高达97%,致密土柱是淤堵的本质;泊松效应和真空荷载幅值对土柱半径以及流泥固结效果的影响十分明显;低幅值真空荷载有利于形成半径小且较为疏松的淤堵区,从而缓解淤堵性状。During the vacuum preloading treatment of slurry ground,the significant improvement is only observed in the soil adjacent to the prefabricated vertical drain(PVD),resulting in the formation of a protruding"soil column"with the PVD as its axis.The presence of soil column,as a unique phenomenon of slurry ground pre-treatment,leads to severe clogging and ineffective treatment results.An axisymmetric vacuum filtration model is established in the coordinate system using the continuity,kinematic and equilibrium equations for both liquid and solid phases of slurry.The moving boundary condition and Poisson's effects associated with the soil column are also incorporated.The growth pattern and clogging behavior of soil columns are investigated through the model and verified by comparing the predicted results with the particle image velocity(PIV)ones.The results show that reduction of permeability coefficient within the soil column is up to 97%,indicating that the dense soil column is the essence of clogging.Furthermore,notable influences of the Poisson's effects and negative pressure on the growth and compression behavior of the soil column are observed.The low amplitude negative pressure promotes formation of the relatively small loose soil columns,thereby mitigating the clogging behavior.

关 键 词：流泥 真空预压 过滤 土柱 淤堵 固结 泊松效应 

分 类 号：TU432[建筑科学—岩土工程]