新建草莓沟2号隧道近接下穿既有隧道施工安全影响分析

为探明新建草莓沟2号隧道近接下穿施工对既有盘道岭隧道整体结构的安全影响,基于Peck公式和温克尔弹性地基梁理论建立数值模型,对既有隧道受下穿施工影响的变形沉降和应力增量变化进行研究.结果表明:既有隧道结构在下穿隧道施工的影响下产生竖向和横向位移,且横向位移变形较竖向更为明显,结构的最大沉降量为1.33 mm,远小于沉降...

Analysis on construction safety influence of newly-built Caomeigou No.2 tunnel close undercrossing existing tunnel

In order to determine the influence of the close undercrossing construction of Caomeigou No.2 tunnel on the overall structure of existing Pandaoling tunnel,a numerical model based on the Peck formula and Winkler elastic foundation beam theory was established,and the deformation settlement and stress increment change of the existing tunnel affected by undercrossing construction were analyzed.The results showed that under the influence of undercrossing tunnel construction,the structure of existing tunnel generated the vertical and transverse displacement,and the transverse displacement deformation was more obvious than the vertical displacement deformation.The maximum settlement of the structure was 1.33 mm,which was far less than the settlement control threshold of 6.35 mm.During the process of undercrossing tunnel construction,the middle section lining of existing tunnel had the longitudinal tensile stress increment and transverse compressive stress increment.The maximum tensile stress increment was 0.68 Mpa,which was far less than the tensile stress control threshold of 1 MPa,and the maximum compressive stress increment was 0.5 MPa,which was far less than the control threshold of 5 MPa.Both the structural settlement deformation and stress increment were less than the control standards of engineering,and the structure of upper existing Pandaoling tunnel was safe and stable.The research results can provide reference for the safe construction of the close undercrossing tunnels.