{"title":"Comparative Numerical Investigation on Behavior of Ordinary and Bio‐Grouted Stone Columns in Clay","authors":"Xiaocong Cai, Ling Zhang","doi":"10.1002/nag.70100","DOIUrl":null,"url":null,"abstract":"The application of biochemical reinforcement techniques in ordinary stone columns (OSCs) has garnered considerable interest, with scarce investigations into their micromechanical behavior and particle‐scale interactions. Three‐dimensional discrete‐element method (DEM) models are developed to analyze the micromechanical behavior of bio‐grouted stone columns (BSCs) and OSCs in clay under vertical loading. The DEM models of clay foundation, OSC, and BSC are successively verified by experimental works. The column‐soil stress ratio (<jats:italic>n</jats:italic>), radial stress coefficient (<jats:italic>K<jats:sub>ps</jats:sub></jats:italic>), contact force distribution, porosity change, coordination number, and load‐displacement behavior of BSC and OSC were compared. Furthermore, the effects of contact‐bond strength (<jats:italic>σ<jats:sub>cb</jats:sub></jats:italic>), column length‐to‐foundation thickness (<jats:italic>L/H</jats:italic>), area replacement ratio (<jats:italic>A<jats:sub>r</jats:sub></jats:italic>), relative density (<jats:italic>D<jats:sub>r</jats:sub></jats:italic>), loading plate diameter‐to‐column diameter (<jats:italic>D<jats:sub>L</jats:sub>/D</jats:italic>), sand particle size‐to‐clay particle size ratio (<jats:italic>S<jats:sub>s</jats:sub>/S<jats:sub>c</jats:sub></jats:italic>) on the behavior of BSC and OSC are systematically investigated and evaluated through a parametric study. The numerical results show that the bulging forms at the bottom of the BSC and within 3<jats:italic>D</jats:italic> in OSC. The passive earth pressure coefficient (<jats:italic>K<jats:sub>p</jats:sub></jats:italic>) design method underestimates the bearing capacity of BSC but overestimates that of OSC and geosynthetic‐encased stone column (GESC). Dilation is observed in OSC, whereas compression occurs in BSC. Short‐floating BSCs with an <jats:italic>L/H</jats:italic> less than 0.33 are not recommended in deep clay deposits. Large‐diameter GESC exhibits a lower bearing capacity, in contrast to the large‐diameter BSC. The bearing capacity of BSC with an <jats:italic>S<jats:sub>s</jats:sub>/S<jats:sub>c</jats:sub></jats:italic> of 2.5–3.5 is similar to the OSC, indicating that the change in size of column material from reduced‐scale models to field‐scale implementations requires careful consideration.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"54 1","pages":""},"PeriodicalIF":3.6000,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal for Numerical and Analytical Methods in Geomechanics","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1002/nag.70100","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The application of biochemical reinforcement techniques in ordinary stone columns (OSCs) has garnered considerable interest, with scarce investigations into their micromechanical behavior and particle‐scale interactions. Three‐dimensional discrete‐element method (DEM) models are developed to analyze the micromechanical behavior of bio‐grouted stone columns (BSCs) and OSCs in clay under vertical loading. The DEM models of clay foundation, OSC, and BSC are successively verified by experimental works. The column‐soil stress ratio (n), radial stress coefficient (Kps), contact force distribution, porosity change, coordination number, and load‐displacement behavior of BSC and OSC were compared. Furthermore, the effects of contact‐bond strength (σcb), column length‐to‐foundation thickness (L/H), area replacement ratio (Ar), relative density (Dr), loading plate diameter‐to‐column diameter (DL/D), sand particle size‐to‐clay particle size ratio (Ss/Sc) on the behavior of BSC and OSC are systematically investigated and evaluated through a parametric study. The numerical results show that the bulging forms at the bottom of the BSC and within 3D in OSC. The passive earth pressure coefficient (Kp) design method underestimates the bearing capacity of BSC but overestimates that of OSC and geosynthetic‐encased stone column (GESC). Dilation is observed in OSC, whereas compression occurs in BSC. Short‐floating BSCs with an L/H less than 0.33 are not recommended in deep clay deposits. Large‐diameter GESC exhibits a lower bearing capacity, in contrast to the large‐diameter BSC. The bearing capacity of BSC with an Ss/Sc of 2.5–3.5 is similar to the OSC, indicating that the change in size of column material from reduced‐scale models to field‐scale implementations requires careful consideration.
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.