邻沣河基坑降水及特长地铁站温度应力研究  

Research on the Dewatering of Foundation Pit near Fenghe River and Temperature Stress of Super Long Subway Station

作　　者：王申侠[1] WANG Shenxia(China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China)

机构地区：[1]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道工程学报》2020年第4期85-90,共6页Journal of Railway Engineering Society

摘　　要：研究目的:为了在沣河一级阶地修建地铁车站,本文以西安地铁森林公园站为例,研究地下水与周边地层有水力联系的基坑邻近河岸地下水处理措施,以及特长地铁站温度应力及混凝土开裂对地下结构的影响。研究结论:(1)在西北地区沣河一级阶地强透水层地层止水帷幕可行的实践效果,为高压旋喷桩在西北地区的应用提供了示范引领作用;(2)强透水地层基坑优先考虑高压旋喷桩止水帷幕工艺,实践证明其安全可行,造价较低,减少工期,环保节能,地面沉降小,对周边建(构)筑物影响较小;(3)特长地下站采用设置诱导缝的方法,可减小温度应力对结构的影响;(4)控制钢筋混凝土的收缩效应及增强其极限拉伸的能力,是控制车站结构产生裂缝的关键;采用细而密的分布钢筋,增大其配筋率能有效减小钢筋混凝土的收缩效应及增强其徐变极限拉伸,能达到在较长范围内减小裂缝开展的效果;(5)本工程的成功实施,对西北地区邻河岸类似强透水地层地下空间开发及及特长地下结构设缝等方面具有参考价值和指导意义。Research purposes:In order to build a subway station on the first terrace of Fenghe River,taking Xi’an subway Forest Park Station as an example,this paper studies the treatment measures of the groundwater near the river bank of the foundation pit with the hydraulic connection between the groundwater and the surrounding strata,as well as the influence of the temperature stress and the concrete cracking of the super long subway station on the underground structure.Research conclusions:(1)The practical effect of the waterproof curtain in the first terrace of Fenghe in the northwest provides a demonstration and leading role for the application of the high-pressure jet grouting pile in the northwest.(2)The high-pressure jet grouting pile waterproof curtain technology is given priority in the foundation pit of the strong permeable layer,which is proved to be safe and feasible in practice,with low cost,reduced construction period,environmental protection and energy saving,small ground settlement,and little impact on the surrounding buildings(structures).(3)The method of setting induced joint in super long underground station can reduce the influence of temperature stress on the structure.(4)Controlling the shrinkage effect of reinforced concrete and enhancing its ultimate tensile capacity is the key to controlling the cracks in the station structure;Using fine and dense distributed reinforcement and increasing its reinforcement ratio can effectively reduce the shrinkage effect of reinforced concrete and strengthen its creep ultimate tensile strength,which can achieve the effect of reducing the crack development in a long range.(5)The successful implementation of the project has important reference value and guiding significance for the development of underground space in similar strong permeable strata adjacent to the river bank in Northwest China and the setting of cracks in super long underground structures.

关 键 词：旋喷桩 止水帷幕 温度应力 诱导缝 混凝土开裂 

分 类 号：TU93[建筑科学—结构工程]