Analytical models for consolidation of combined composite ground improved by impervious columns and vertical drains
Analytical models for consolidation of combined composite ground improved by impervious columns and vertical drains
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DOI：
10.1002/nag.2770
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发表时间：
2018-04
影响因子：
4
通讯作者：
M. Lu;H. Jing;Annan Zhou;K. Xie
中科院分区：
文献类型：
--
作者：
M. Lu;H. Jing;Annan Zhou;K. Xie
近年来，人们提出了一种新的地基加固技术，即防渗柱与竖向排水的联合使用，并在许多现场工程中得到了应用，以加速软土地基的固结和提高其承载力。为了涵盖不透水柱和垂直排水管的可能分布模式，提出了2种分析模型，包括土内向外流动的模型A和向内流动的模型B，通过考虑以下因素来预测复合地基的固结：(1)不透水柱和垂直排水管的扰动效应，(2)垂直排水管的井阻力，(3)时变荷载。提出的分析模型预测的平均固结程度与几个现有的解决方案进行了比较，然后与文献中的实测数据进行了比较。利用所提出的解析解对复合地基的固结特性进行了研究。结果表明：竖向排水与防渗柱联合使用比单独使用具有显著的加速软土固结速率的作用。两种分析模型预测的平均固结度与实测数据吻合较好。与B模型相比，A模型通常预测更快的固结速率，因为排水路径更短。影响复合地基固结性能的因素很多，如荷载方案、抗渗柱与竖向排水的分布形式及扰动效应、抗渗柱与土的压缩模量比等。
In recent years, a new technique of ground improvement, which involves the combined use of impervious column and vertical drains, has been proposed and utilized in many field projects to accelerate consolidation and increase bearing capacity of soft soil ground. To cover the possible distribution patterns of impervious columns and vertical drains, 2 analytical models, including Model A with outward flow and Model B with inward flow within the soils, are proposed to predict the consolidation of combined composite ground by considering the following factors: (1) disturbance effects of both impervious columns and vertical drains, (2) the well resistance of vertical drains, and (3) time‐variant loadings. The average degrees of consolidation predicted by the proposed analytical models are compared with several existing solutions and then against the measured data in the literature. The consolidation behavior of a combined composite ground is investigated by the proposed analytical solutions. The results show that the combined use of impervious columns and vertical drains can remarkably accelerate the consolidation rate of soft soils compared with the single use of either of them. The average degrees of consolidation predicted by both analytical models agree well with the measured data. Compared with Model B, Model A usually predicts a faster consolidation rate because of a shorter drainage path. Many factors can influence consolidation behavior of combined composite ground, such as loading scheme, distribution patterns and the disturbance effects of impervious columns and vertical drains, and compression modulus ratio of impervious column to soil.