摘要
研究目的:随着城市轨道交通网格化发展和城市地下大空间开发需求的增长,地铁穿越河流成为难题及重点。研究地下水与周边地层有水力联系的河岸边强透水砂卵石地层地下空间深基坑开挖支护措施成为必须。本文以西安地铁1号线浐河站为例,对下穿浐河强透水砂卵石地层的地铁站及地下大空间开发的基坑支护结构设计进行研究。研究结论:(1)在强透水层砂卵石地层中深基坑开挖采用地下连续墙的基坑支护形式,为地下连续墙在浐河岸边的应用提供了示范效果;(2)地下连续墙在砂卵石地层中施工易塌孔问题可通过在护壁泥浆中掺加膨润土等措施来改良;(3)强透水地层地下连续墙墙幅间优先采用锁口管连接,可起到良好止水效果;(4)浐河岸边随季节变化,水位变化较高,可采取在地下水位变化幅度2.5 m范围以上浅部基坑放坡开挖+深部基坑地下连续墙支护结构形式,其经济效果明显,为后续地下连续墙在西北地区富水砂卵石地层中的应用起到示范引领作用;(5)本工程的成功实施,可为西北地区浐河岸边类似强透水砂卵石地层地下空间开发及深基坑支护结构设计等方面提供参考和指导。
Research purposes:With the development of urban rail transit grid and the increasing demand of urban underground space development,subway crossing river has become a difficult and important problem.It is necessary to study the excavation and support measures of deep foundation pit in the strong permeable sandy pebble stratum on the bank side where the groundwater has hydraulic connection with the surrounding strata.In this paper,taking Chanhe station of Xi’an Metro Line 1 as an example,the design of foundation pit supporting structure for subway station and underground large space development through Chanhe River is studied.Research conclusions:(1)In the sand gravel stratum of strong permeable layer,the support form of diaphragm wall is adopted in the excavation of deep foundation pit,which provides a demonstration effect for the application of diaphragm wall on the bank of Chanhe River.(2)The problem of collapsible hole of diaphragm wall in sandy cobble stratum can be improved by adding bentonite into the retaining slurry.(3)The interstice between the diaphragm walls in strong permeable stratum should be connected with the lock pipe preferentially,which can stop the water well.(4)The change of water level along Chanhe River bank is higher with the change of seasons.The slope excavation of shallow foundation pit and underground continuous wall support structure of deep foundation pit above 2.5 m range can be adopted.The economic effect is obvious,which will play an exemplary role in the subsequent application of diaphragm wall in water rich sandy cobble stratum in Northwest China.(5)The successful implementation of the project can provide reference and guidance for the development of underground space and the design of supporting structure of deep foundation pit in similar strong permeable sandy cobble stratum on the bank of Chanhe River in Northwest China.
作者
王申侠
WANG Shenxia(China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China)
出处
《铁道工程学报》
EI
北大核心
2020年第8期11-14,64,共5页
Journal of Railway Engineering Society
关键词
地下连续墙
膨润土
锁口管
联合支护
复合墙结构
underground diaphragm wall
bentonite
lock pipe
combined support
composite wall structure
