摘要
确定了挤密桩处理大厚度自重湿陷性黄土地区综合管廊地基的合理处理范围,揭示了挤密桩处理地基效果随地基处理深度的变化规律,研究了挤密桩复合地基在地基浸水后的入渗规律及沉降特征。在大厚度湿陷性黄土场地进行不同深度的灰(素)土挤密桩地基处理试验及埋设TDR水分计和分层沉降仪的工后浸水试验。研究结果表明,随着地基处理深度的增大,各试验区挤密桩复合地基桩间土挤密效果呈增强趋势;挤密桩复合地基桩间土的干密度增长率随地基处理深度的增大而增大;挤密桩复合地基的抗渗性能随地基处理深度的增大而增强;外界水分在挤密桩复合地基中的入渗规律呈现出明显的阶段性,基本由4个阶段组成;挤密桩复合地基桩间土受水浸湿时的沉降变形,随地基处理深度的增大而减小,且呈现出明显的阶段性,基本由5个阶段组成。根据研究结果,在采取有效的防水措施的情况下建议地基处理深度为9~12m,处理宽度为管廊每边延伸控制在2m,作为大厚度自重湿陷性黄土地区综合管廊的合理地基处理范围。
This study determined the reasonable treatment range of utility tunnel foundation in self-weight collapsible loess with large thickness.Meanwhile,the regularity of the compacting effect on the foundation was revealed with various treatment depths,and the infiltration law and settlement characteristics of composite foundation after immersion were analyzed.With different depths of lime soil (pure soil) compaction piles,the foundation treatment experiments were conducted on the collapsible loess with large thickness. Moreover,post-work immersion tests were carried out by embedding TDR moisture meter and layered settlement instrument.The results show that with increasing the treatment depth of composite foundation,the impermeability of composite foundation, compacting effect and dry density of soil between piles all increase.The external water presents distinct multistage infiltration in composite foundation,including four stages basically.The deformation of wetting soil between piles decreases with the increase of the foundation treatment depth.Besides,it shows obvious five stages.According to the research results,under the condition of effective waterproof measures,the reasonable treatment range is summarized as follows:the treatment depth should be controlled in the range of 9-12 m,and the treatment width should be controlled within 2 m extended from each side of tunnel.
作者
朱彦鹏
杜晓启
杨校辉
栗慧王君
ZHU Yan-peng;DU Xiao-qi;YANG Xiao-hui;LI Hui-jun(College of Civil Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China;Western Center of Disaster Mitigation in Civil Engineering of Ministry of Education,Lanzhou University of Technology,Lanzhou,Gansu 730050,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第8期2914-2924,共11页
Rock and Soil Mechanics
基金
教育部长江学者创新团队支持计划项目(No.IRT-17R51)
甘肃省科技重大专项计划项目(No.1302FKDA030)~~
关键词
大厚度自重湿陷性黄土
综合管廊地基
挤密桩
合理处理范围
工后浸水试验
入渗规律
self-weight collapsible loess with large thickness
utility tunnel foundation
compaction piles
reasonable treatment range
post-work immersion test
infiltration law
作者简介
第一作者:朱彦鹏,男,1960年生,硕士,教授,博士生导师,主要从事地基处理及事故分析与处理方面的研究工作。E-mail:zhuyp1@163.com;通讯作者:杜晓启,男,1989年生,硕士,助理工程师,主要从事非饱和土的工程性质及应用研究。E-mail:Dxqlee@163.com.
