黄土-古土壤地层深竖井受力变形特征研究  

Research on the Stress and Deformation Characteristics of Vertical Shafts in Loess Paleosol Stratum

作　　者：罗章波 亢佳伟 李仑 邓国华 LUO Zhangbo;KANG Jiawei;LI Lun;DENG Guohua(China Railway Fifth Survey and Design Institute Group Co.Ltd,Beijing 102600,China;Instute of Geotechnical Engineering,Xi′an University of Technology,Xi′an,Shaanxi 710048,China;Xi′an Loess Underground Engineering Technology Consulting Co.Ltd,Xi′an,Shaanxi 710054,China)

机构地区：[1]中铁第五勘察设计院集团有限公司,北京102600 [2]西安理工大学,西安710048 [3]西安黄土地下工程技术咨询有限公司,西安710054

出　　处：《铁道工程学报》2024年第3期1-6,16,共7页Journal of Railway Engineering Society

基　　金：国家自然科学基金(52178355);西安市轨道交通集团有限公司科技研究开发计划项目(D15-YJ-152021007);中铁第五勘察设计院集团有限公司科技研究开发计划项目(T5Y2021-B03)。

摘　　要：研究目的:为准确认识黄土-古土壤地层条件下的深竖井受力变形特征,以53.5 m深圆形竖井工程为依托,开展竖井侧向土压力、变形、结构内力及周边地层的竖直和水平向变形的系统监测。研究结论:(1)黄土-古土壤地层深竖井开挖过程中,井壁结构整体变形较小,水平变形“先挤出后收敛”,竖向变形“先下沉后隆起”,竖井开挖至设计深度后,15~30 d进入结构受力变形稳定阶段;(2)竖井井壁收敛变形、侧向土压力和结构内力在深度方向上存在拐点,出现在0.5~0.7倍竖井设计深度处,其受力变形指标和土层性质存在良好的对应关系,在古土壤范围内,井壁变形量和土压力明显减小,约为邻近深度处黄土层的40%~50%,古土壤的存在,限制了竖井变形和土压力的发展;(3)黄土-古土壤地层深竖井井壁结构侧向土压力与静止土压力和主动土压力有显著差异,在0~12 m深度范围内,侧向土压力接近静止土压力;12~28 m范围内,侧向土压力接近主动土压力;28~48 m范围内,侧向土压力均小于主动土压力,为其35%~65%;(4)本研究成果可为相近地层条件下深竖井的土压力计算和支护结构设计提供参考依据。Research purposes:In order to accurately investigate the deformation characteristics of deep vertical shafts under loess paleosol geological conditions,a 53.5 m deep circular shaft was used as a support project to systematically monitor lateral soil pressure,deformation,structural internal force,and vertical and horizontal deformation of surrounding strata.Research conclusions:(1)During the excavation process of a deep vertical shaft,the overall deformation of the shaft wall structure is relatively small,with horizontal deformation"extruding first and then converging"and vertical deformation"sinking first and then uplifting".After the excavation of the vertical shaft reaches the design depth,it enters the stable stage after 15~30 days.(2)There are inflection points in the depth direction for the convergence deformation of the shaft wall,lateral soil pressure,and structural internal force,all of which occur at a depth of 0.5~0.7 times the design depth of the shaft.There is a good corresponding relationship between the stress deformation index and the soil properties.In the range of paleosol,the shaft wall deformation and soil pressure significantly decreased,about 40%~50%of the loess layer at the adjacent depth.The existence of paleosol significantly restricted the development of shaft deformation and soil pressure.(3)The lateral soil pressure of deep shaft lining structure in loess paleosol stratum is significantly different from the static soil pressure and active earth pressure.Within the depth range of 0~12 m,the lateral earth pressure is close to the static soil pressure;Within the range of 12~28 m,the lateral soil pressure is close to the active soil pressure;Within the range of 28~48 m,the lateral soil pressure is approximately 35%~65%of the active soil pressure.(4)The research result can provide a reference basis for calculating soil pressure and supporting structure design of vertical shafts under such geological conditions.

关 键 词：深竖井 黄土-古土壤结构剖面 现场原位监测 受力变形特征 

分 类 号：TU444[建筑科学—岩土工程]