摘要
随着城市轨道交通的快速发展,轨道交通路网不断扩大,频繁出现了穿越工程邻近既有线施工的现象.为此,以青岛某紧邻既有高架区间桥墩的地铁基坑施工为背景,针对土岩结合地层基坑开挖对既有线的保护措施进行研究.根据基坑地质及周边环境条件通过数值模拟方法最终确定了基坑的加固方案,然后对支护方案进行分析检算.最终实践证明,基坑最大水平位移约为9.5mm,地表沉降为13 mm,满足设计要求并得出如下结论:在条件允许情况下,应对既有线与基坑间的软土体进行注浆加固;对于土岩结合地层条件下的地铁明挖基坑,应加强地铁基坑的支护刚度;严格控制爆破振速,减少对土体的扰动.
With the development of urban rail transit and the expanding network of rail transit,the construction circumstance of the crossing project adjacent to the existing line is common.Hence,this paper made a research on the protection measures of the existing railway in light of the excavation of foundation pit in soil-rock strata,which was based on the construction of a subway foundation pit adjacent to an existing viaduct pier in Qingdao.The reinforcement scheme of foundation pit was finally determined by numerical simulation method according to the geological conditions and its surrounding environment,and then the supporting scheme was analyzed and checked.The practice finally showed that the maximum horizontal displacement of the foundation pit was about 9.5 mm and the surface settlement was 13 mm,which could meet the design requirements.Some conclusions were drawm as the following:firstly,in some conditions,grouting reinforcement should be carried out in soft soil between existing railway and foundation pit.Secondly,the supporting sifness of subway foundation pit should be strengthened for the open.cut foundation pit of metro under the condition of soil-rock strala.Thirdly,the blasting vibration velocity was strictly controlled to reduce the disturbance to the soil.
作者
邹玉娜
Zou Yuna(China Railway Fifth Survey and Design Institute Group Co.Ltd.,Beijing 102600,China)
出处
《铁道建筑技术》
2019年第S02期192-196,共5页
Railway Construction Technology
基金
中铁第五勘察设计院集团有限公司科研课题(Y2012019).
关键词
紧邻既有运营线路
基坑支护
注浆加固
支护刚度
爆破振速
adjacent to existing line
support for foundation pit
grouting reinforcement
supporting stiffness
blasting vibration velocity
