Abstract

The high-water-content sludge produced through dredging seriously restricts marine ecological environments. Vacuum preloading methods (involving prefabricated vertical drains (PVDs)) are widely used to dewater and consolidate sludge ground, but these methods require long treatment periods and have deprived reinforcement effects. To overcome the limitations of PVD vacuum preloading, a prefabricated radiant drain (PRD) vacuum preloading method is proposed is this study by adding a prefabricated horizontal drain (PHD) to the PVD framework. Physical model tests are conducted under PVD and PRD vacuum preloading conditions, and a large-strain three-dimensional finite element (FE) model is established and validated against the physical model test data. FE parametric analyses are also conducted to evaluate the key factors influencing the PRD, i.e., the PHD length and spacing. The results show that the reinforcement effect of PRD vacuum preloading is better than that of PVD vacuum preloading. The ground settlement effect increases as the PHD length increases and the PHD spacing decreases. The settlement and pore water pressure metrics show elliptical distributions with an increasing PHD length. Through this work, an applicable sludge ground treatment design procedure is suggested based on parametric analyses; these findings can provide a reference for designing sludge ground treatments in the future.

摘要

疏浚过程中产生的高含水污泥严重制约着海洋生态环境。真空预压法（涉及预制垂直排水沟（PVDs））被广泛用于污泥地面的脱水和加固，但这些方法需要较长的处理周期并且剥夺了加固效果。为了克服 PVD ​​真空预加载的局限性，本研究提出了一种预制辐射排水管 (PRD) 真空预加载方法，通过在 PVD ​​框架中添加预制水平排水管 (PHD)。在PVD和PRD真空预压条件下进行物理模型试验，建立大应变三维有限元（FE）模型，并根据物理模型试验数据进行验证。还进行了有限元参数分析以评估影响珠三角的关键因素，即 PHD 长度和间距。结果表明，PRD真空预压加固效果优于PVD真空预压。地面沉降效应随着 PHD 长度的增加和 PHD 间距的减小而增加。随着 PHD 长度的增加，沉降和孔隙水压力指标呈椭圆分布。通过这项工作，基于参数分析提出了适用的污泥地面处理设计程序；这些研究结果可为今后设计污泥地基处理提供参考。随着 PHD 长度的增加，沉降和孔隙水压力指标呈椭圆分布。通过这项工作，基于参数分析提出了适用的污泥地面处理设计程序；这些研究结果可为今后设计污泥地基处理提供参考。随着 PHD 长度的增加，沉降和孔隙水压力指标呈椭圆分布。通过这项工作，基于参数分析提出了适用的污泥地面处理设计程序；这些研究结果可为今后设计污泥地基处理提供参考。