摘要
[目的]为了研究处置湿陷性黄土地层的优化措施,需要对黄土浸水湿陷后隧道结构的变形特性进行研究。[方法]介绍了湿陷性黄土隧道地基处置方法;以穿越湿陷性黄土地层的盾构地铁隧道为例,采用三轴搅拌桩法作为地基处置方法,采用MIDAS GTS软件建立数值计算模型,分析在不同处置深度及处置宽度情况下,黄土地基浸水湿陷变形后对地铁隧道结构各部位的竖向位移和衬砌结构内力的影响。结合隧道结构各部位竖向位移和衬砌结构内力的变化趋势、施工经济性及相关要求对处置方案进行优化。在3种处置宽度和7种处置深度条件下,分析隧道拱腰、拱顶、拱底处竖向位移、弯矩、主应力的变化规律,给出最合适的处置建议。[结果及结论]处置深度越大,隧道结构各部位的竖向位移越小,衬砌结构内力越大;处置宽度越大,隧道结构各部位的竖向位移与衬砌结构内力越小。本案例工程中,最佳处置深度为7 m,最佳处置宽度为16 m。
[Objective]To study the optimization measures for treating waterlogged collapsible loess stratum,it is necessary to investigate the deformation characteristics of tunnel structures after loess collapse by waterlogging.[Method]The foundation treatment for the waterlogged collapsible loess tunnels is introduced.Taking a shield metro tunnel crossing through waterlogged collapsible loess stratum as example,the method of three-axis mixing pile is adopted as the foundation treatment method.By establishing a numerical calculation model using MIDAS GTS software,the influence of waterlogged deformation of loess foundation on the vertical displacement of various metro tunnel structure parts and the internal force of lining structure is analyzed under different treatment depths and treatment widths.The treatment scheme is optimized based on the changing trends of tunnel parts vertical displacement and lining structure internal force,the construction economy and relevant requirements.Under conditions of three treatment widths and seven treatment depths,variation laws of vertical displacement,bending moment,and principal stress at the tunnel arch waist,vault,and invert are analyzed for the most suitable treatment recommendation.[Result&Conclusion]The greater the treatment depth,the smaller the vertical displacement of tunnel structure parts and the larger the lining structure internal force;the larger the treatment width,the smaller the vertical displacement and the internal force mentioned above.In this case study engineering,the optimal treatment depth is 7 m,and the optimal treatment width is 16 m.
作者
潘红伟
吴友川
段宇昕
张玉伟
何十美
PAN Hongwei;WU Youchuan;DUAN Yuxin;ZHANG Yuwei;HE Shimei(China Railway Beijing Engineering Group First Engineering Co.,Ltd.,710100,Xi’an,China;School of Civil Engineering,Xi’an University of Architectural Technology,710055,Xi’an,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,710055,Xi’an,China;China Railway Construction Bridge Engineering Bureau Group Co.,Ltd.,300300,Tianjin,China)
出处
《城市轨道交通研究》
北大核心
2024年第7期261-265,274,共6页
Urban Mass Transit
基金
陕西省自然科学基础计划项目(2019JQ762)
陕西省教育厅专项项目(20JK0709)。
关键词
地铁
隧道
湿陷性黄土地层
处置方案
metro
tunnel
waterlogged collapsible loess stratum
treatment scheme
