土工织物联合真空预压对加固疏浚淤泥地基固结性能的影响  

Effect on Consolidation Performance of Dredged Clay Foundation by Geotextile Combined with Vacuum Preloading

作　　者：曾芳金[1] 许士伟 符洪涛 李校兵 蔡瑛 ZENG Fang-jin;XU Shi-wei;FU Hong-tao;LI Xiao-bing;CAI Ying(Jiangxi Provincial Key Laboratory of Environmental Geotechnology Engineering Disaster Control,School of Architectural and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;Innovation Center of Tideland Reclamation Ecological Protection,Key Laboratory of Soft Soil Foundation and Engineering Technology of Zhejiang Province,College of Architecture Engineering,Wenzhou University,Wenzhou 325035,China)

机构地区：[1]江西理工大学建筑与测绘工程学院,江西省岩土与工程灾害控制重点实验室,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,浙江省海涂围垦及其生态保护协同创新中心,温州325035

出　　处：《科学技术与工程》2022年第23期10205-10213,共9页Science Technology and Engineering

基　　金：国家自然科学基金(52178348,52178350);浙江省自然科学基金(LY20E080029);温州市科技项目(S20210004)。

摘　　要：传统真空预压法采用预制竖向排水板(prefabricated vertical drain, PVD)处理疏浚淤泥,已经广泛应用于工程实践中,但是在真空预压过程中PVD周围严重的淤堵效应会引起加固土体不均匀沉降和土体侧向位移较大等现象,这严重阻碍了PVD在疏浚淤泥地基处理中的应用。室内模型试验,研究了土工织物与PVD联合处理疏浚淤泥对减缓PVD淤堵效应和土体侧向位移较大的影响。对比分析不同土工织物间距和直径大小对加固土体的表面沉降、孔隙水压力和土体侧向位移等方面的影响,试验结果表明该方法对缓解以上问题具有明显效果。再进一步利用Plaxis数值模拟软件,假设将室内模型试验中圆形土工织物的直径等效为等长度的水平排水板(prefabricated horizontal drain,PHD)进行模拟,模拟结果与实测结果吻合良好,验证了本文提出的假设方法是可行的。在数值模拟中,通过不断改变PHD长度和间距以及PVD的直径大小并对模拟结果进行分析,间接地建立排水板等效直径与以上变量之间的关系,从而对土工织物联合真空预压在工程实践中的应用提供参考。Traditional vacuum preloading with prefabricated vertical drain(PVD) to treat dredged clay has been a widely used practice in engineering. However, in the process of vacuum preloading, serious silting around PVD leads to uneven settlement and a large lateral displacement of soil, which seriously hinders the use of PVD in the treatment of dredged clay foundations. Through lab model tests and finite element analysis, the effects of the combined treatment of dredged clay with geotextile and PVD on alleviating the silt blocking effect of PVD and the large lateral displacement of soil was examined, the effects of different geotextile spacing and diameters on soil surface settlement, excess pore water pressure and soil lateral displacement was also compared and analysed. Further, the circular geotextile diameter equivalent to prefabricated horizontal drain(PHD) of the same length was simulated by Plaxis numerical simulation software in the lab model test. The simulation results were reflected in the actual measured results, which verified the feasibility of the proposed method. In the numerical simulation, by changing the PHD diameter and spacing, the simulation results were analysed, and the relationship between the equivalent diameter of the drainage plate and the spacing and diameter of geotextiles was indirectly established, which had significant implications for the application of geotextile reinforcement combined with vacuum preloading in engineering practice.

关 键 词：土工织物 PVD淤堵 Plaxis 2D 疏浚淤泥 

分 类 号：TU472.5[建筑科学—结构工程]