Analytical Solutions for Composite Foundations Reinforced by Partially Penetrated Stone Columns and Vertical Drains

IF 3.4 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

International Journal for Numerical and Analytical Methods in Geomechanics Pub Date : 2024-10-22 DOI:10.1002/nag.3874

Chuanxun Li, Xiangzong Lu

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引用次数: 0

Abstract

When stone columns or vertical drains are applied to improve soils, it is common to face situations where the soft soil layer is too thick to be penetrated completely. Although consolidation theories for soils with partially penetrated vertical drains or stone columns are comprehensive, consolidation theories for impenetrable composite foundations containing both two types of drainage bodies have been few reported in the existing literature. Equations governing the consolidation of the reinforced zone and unreinforced zone are established, respectively. Analytical solutions for consolidation of such composite foundations are obtained under permeable top with impermeable bottom (PTIB) and permeable top with permeable bottom (PTPB), respectively. The correctness of proposed solutions is verified by comparing them with existing solutions and finite element analyses. Then, extensive calculations are performed to analyze the consolidation behaviors at different penetration rates, including the total average consolidation degree defined by strain or stress and the distribution of the average excess pore water pressure (EPWP) along the depth. The results show that the total average consolidation rate increases as the penetration rate increases; for some composite foundations with a low penetration rate, the consolidation of the unreinforced zone cannot be ignored. Finally, according to the geological parameters provided by an actual project, the obtained solution is used to calculate the settlement, and the results obtained by the proposed solution are in reasonable agreement with the measured data.

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用部分贯入式石柱和垂直排水沟加固复合地基的分析解决方案

当采用石柱或竖向排水体改良土壤时，通常会遇到软土层太厚而无法完全穿透的情况。虽然针对部分贯入竖向排水沟或石柱的土壤的固结理论比较全面，但针对包含这两种排水体的不透水复合地基的固结理论在现有文献中却鲜有报道。本文分别建立了加固区和非加固区的固结方程。在顶部透水、底部不透水（PTIB）和顶部透水、底部透水（PTPB）的情况下，分别获得了这种复合地基固结的分析解。通过与现有解决方案和有限元分析进行比较，验证了所提出解决方案的正确性。然后，通过大量计算分析了不同渗透率下的固结行为，包括由应变或应力定义的总平均固结度以及沿深度的平均过剩孔隙水压力（EPWP）分布。结果表明，总平均固结度随贯入度的增加而增加；对于一些贯入度较低的复合地基，不能忽视未加固区的固结。最后，根据某实际工程提供的地质参数，利用所得到的方案计算沉降量，所提出的方案得到的结果与实测数据合理吻合。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal for Numerical and Analytical Methods in Geomechanics 工程技术-材料科学：综合

CiteScore

6.40

自引率

12.50%

发文量

160

审稿时长

9 months

期刊介绍： The journal welcomes manuscripts that substantially contribute to the understanding of the complex mechanical behaviour of geomaterials (soils, rocks, concrete, ice, snow, and powders), through innovative experimental techniques, and/or through the development of novel numerical or hybrid experimental/numerical modelling concepts in geomechanics. Topics of interest include instabilities and localization, interface and surface phenomena, fracture and failure, multi-physics and other time-dependent phenomena, micromechanics and multi-scale methods, and inverse analysis and stochastic methods. Papers related to energy and environmental issues are particularly welcome. The illustration of the proposed methods and techniques to engineering problems is encouraged. However, manuscripts dealing with applications of existing methods, or proposing incremental improvements to existing methods – in particular marginal extensions of existing analytical solutions or numerical methods – will not be considered for review.