摘要
本文结合北京地铁6号线工程,通过Fl AC软件,根据隧道叠落位置建立四种不同工况下的模型,经过计算分析得出结论:上下隧道垂直叠落时,既有下线隧道结构内力、塑性区分布以及拱顶的地层位移都减小;两隧道净距由2 m向3 m的变化过程中,既有下线隧道结构的内力、塑性区范围和地层位移都逐渐增大且呈非对称分布,并向上线隧道开挖方向偏转;两隧道净距为6 m时,下线隧道结构的受力情况与单洞隧道基本相同。因此,当两隧道净距小于6 m时,开挖上线隧道前应对下线隧道的地层进行预先加固。
In this paper,combined with the project of Beijing Metro Line 6,the models under four different engineering conditions were established according to the location of the overlapping tunnel by Fl AC software. The results showed that the existing structural internal force and plastic zone and dome stratum displacement were reduced when the new tunnel was excavated above the existing tunnel. In the process of tunnel distance change from 2 meters to 3 meters,the existing structural internal force and plastic zone and dome stratum displacement were increased and showed non-symmetrical distribution and deflection. Stress conditions of the above tunnel were the same as the existing tunnel when distance of two tunnels became 6 meters. Therefore,when the distance of two tunnels was less than 6 meters,the existing tunnel stratum should be pre-reinforced before the new tunnel was excavated above the existing tunnel.
出处
《铁道建筑技术》
2017年第2期9-12,共4页
Railway Construction Technology
基金
北京城建设计发展集团股份有限公司科技创新项目(2011-11)
关键词
叠落隧道
结构内力
塑性区
地层变形
数值模拟
overlapping tunnels
structural internal force
plastic zone
stratum displacement
numerical simulation
