土柱半径对疏浚淤泥真空固结的影响  

Influence of soil column radius on vacuum consolidation of dredged slurry

作　　者：吴建奇[1] 刘祥 李敏[1] 符洪涛 李校兵 蔡瑛 WU Jianqi;LIU Xiang;LI Min;FU Hongtao;LI Xiaobing;CAI Ying(College of Civil and Surveying Engineering,Jiangxi Provincial Key Lab of Environmental Geotechnical and Engineering Disaster Control,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,P.R.China;College of Civil Engineering and Architecture,Key Laboratory of Engineering and Technology for Soft Soil Foundation and Tideland Reclamation of Zhejiang Province,Wenzhou University,Wenzhou 325035,Zhejiang,P.R.China)

机构地区：[1]江西理工大学土木与测绘工程学院,江西省环境岩土与工程灾害重点实验室,江西赣州341000 [2]温州大学建筑工程学院,浙江省软弱土地基与海涂围垦工程技术重点实验室,浙江温州325035

出　　处：《土木与环境工程学报(中英文)》2025年第2期57-65,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(52178348、51878512、52178350、51768025);浙江省自然科学基金(LY20E080029);温州市科研项目(S20210004)。

摘　　要：预制竖向排水板(PVD)-真空预压技术是处理疏浚淤泥地基常用的有效方法之一。然而,在使用真空预压法处理疏浚淤泥过程中,PVD周围会产生自上而下半径逐渐减小的致密土层(土柱),从而延缓土体的固结速率。针对该问题,假设土柱半径随深度呈线性衰减,并基于等应变假设,在Hansbo固结理论的基础上推导了考虑土柱半径随深度衰减的固结方程;利用该方程进行计算,探究土柱淤堵区的渗透系数大小、土柱半径的大小以及土柱半径的衰减程度对土体固结速率的影响,并与已有室内试验实测数据进行对比。结果表明:土柱淤堵区渗透系数越小,孔压消散越慢,固结速率越小;随着土柱半径的逐渐增大,土体的固结速率逐渐降低;土柱半径衰减后的残余系数越小,土柱半径衰减程度越大,对软弱区土体固结的影响越小,土体的固结速率越快;在考虑土柱半径衰减的情况下,计算结果与试验实测结果吻合较好。Prefabricated vertical drainage plate(PVD)-vacuum preloading method is effective in improving the dredged slurries.However,during the operating process,a dense area(soil column)with a gradually decreasing radius from top to bottom would be generated around the PVD,delaying the soil consolidation rate.Aimed at it,this paper assumed that the soil column radius attenuates linearly with depth,and based on the assumption of equal strain,and the Hansbo,s consolidation theory,the consolidation equation considering the change of soil column radius with depth is deduced.At the same time,by calculating the equation above,the influences of the permeability coefficient,the radius of the soil column and the variation of the radius of the soil column along the depth on the soil consolidation rate were explored,and compared with the existing laboratory test data.The result shows that the smaller the permeability coefficient of the soil column,the slower the dissipation of pore water pressure,and the slower the consolidation rate.As the soil column radius gradually increases,the soil consolidation rate gradually decreases.The smaller the residual coefficient after the attenuation of the soil column radius,the greater the attenuation degree of the soil column radius along the depth,the smaller the influence on the soil consolidation in the weak area,and the faster the soil consolidation rate.In the case of considering the soil column radius attenuation with depth,the presented results are in good agreement with the experimental findings.

关 键 词：真空预压法 疏浚淤泥 固结理论 土柱半径 Hansbo解 

分 类 号：TU447[建筑科学—岩土工程] TU472.3[建筑科学—土工工程]