摘要
收敛变形超限是软土地区地铁盾构隧道结构的典型病害。目前,业内主要采用内钢圈的加固处理办法,但其合理的加固时机尚不明确。鉴于此,通过建立能够体现黏结界面滑移破坏的地铁三维盾构隧道精细化有限元模型,研究了盾构隧道在不同收敛变形条件下进行内钢圈加固后衬砌环的收敛变形、接缝张开量、螺栓应力和内钢圈应力。研究结果表明:①内钢圈加固后,衬砌环达到屈服时,钢板应力水平尚未达到材料自身的强度极限,但部分界面已经剥离。②加固时机对于加固后衬砌环结构的变形破坏特征有明显影响。最合理的加固时机应当是一个安全界限,早于安全上限加固,则衬砌环结构破坏具有较强的突发性,迟于安全下限加固,则结构会产生过大的变形量。
Convergence deformation overrun is a typical disease of subway shield tunneling in soft soil area.Currently,the industry mainly adopts the reinforcement of bonded steel ring,but the reasonable reinforcement opportunity of which is not clear.In view of this,a refined finite element model of 3D shield tunnel is established,which can reflect the interfacial bond slip failure,and the convergence deformation of lining ring after reinforcement,the joint opening,bolt stress and internal steel ring stress under different previous shield tunnel deformation conditions are studied.The results show that:①when the lining ring reaches yield after the reinforcement of bonded steel ring,the stress level of steel plate has not reached the strength limit of the material itself,but some of the interface has been stripped off;②the reinforcement opportunity has a significant impact on the deformation and failure characteristics of the reinforced lining ring structure.In conclusion,the most reasonable time for steel ring reinforcement should be a safety boundary.Earlier or later than safety upper limit,the deformation and failure of lining ring structure will have a strong suddenness or produce an excessive deformation.
作者
张伯林
郑军
沈晓伟
ZHANG Bolin;ZHENG Jun;SHEN Xiaowei(Nanjing Metro Group Co.,Ltd.,210018,Nanjing,China)
出处
《城市轨道交通研究》
北大核心
2020年第10期26-29,共4页
Urban Mass Transit
关键词
地铁
盾构隧道
内钢圈加固
加固时机
界面黏结滑移
metro
shield tunnel
reinforcement of bonded steel ring
reinforcement opportunity
interfacial bond slip
