摘要
城市地下空间开发中经常遇到已建地铁隧道上方进行基坑开挖的情况,如何有效控制地铁隧道的隆起量是工程界普遍关心的问题.首先建立了三维有限元模型,分析表明,在工程量相当的情况下,门式加固方式在控制地铁位移上,优于等厚加固方式,相对于不加固而言,地铁隧道上隆量减少51.6%;然后,根据实测数据动态调整设计方案,在监测数据达到预警值后,明确了抽条分层分块开挖,快速开挖、快速等量加载的基本措施,有效将隧道最大隆起量控制在可接受范围;最后,结合现场情况,分析了监测数据与预测值差异较大的原因,总结了隧道上隆监测值与施工进度相关经验,研究表明,下卧隧道累计变形占比基本位于1~1.5倍的累计卸荷比区域.通过对一个工程实例的全过程设计和施工做展开研究,给设计人员提供了可借鉴的思路.
The method for effectively controlling the uplift of underneath existing tunnel due to above deep excavation unloading is of great concern in the industry.A 3D finite element model is founded,which shows that different thickness reinforcement is better than equal thickness one of controlling the uplift considering equal project cost.Compared with no reinforcement,vertical displacement of tunnel decrease 51.6%.The design is adjusted dynamically based on measured data.W hen the monitoring data rises to warning value,the basic measures of layered and block excavation,fast excavation and equal loading are carried out,which controlling.the maximum uplift of tunnel within an acceptable range effectively.The reasons for large difference between the monitored data and predicted values are analyzed,at the same time,some experience between monitoring.value and construction progress are summarized.The research shows that the accumulative deformation proportion of the underlying tunnel is basically located in the accumulative unloading ratio area of 1~1.5 times.This paper studies the whole process design and construction of an engineering example,which provides a reference for designers.
作者
宗翔
ZONG Xiang(Tongji Architectural Design(Group)Co.,Ltd.,Shanghai 200092,China)
出处
《结构工程师》
北大核心
2020年第3期198-205,共8页
Structural Engineers
关键词
门式加固
实测数据
动态调整
快速等量加载
different thickness reinforcement
measured data
dynamical adjustment
fast equal loading
