浅埋隧道施工过程中的围岩变形及控制研究

Research on Deformation and Control of Surrounding Rock During the Construction of Shallow-buried Tunnel

为了探究弹性模量、内摩擦力及粘聚力等围岩参数对隧道围岩施工变形的影响,同时分析管棚布设对围岩变形的控制效果,文章以某公路隧道工程为依托,通过Midas有限元软件建立模型,通过模拟计算得出以下结论:(1)竖向位移发生在围岩各部位,拱顶、拱肩、拱腰处为沉降,拱脚及隧底为隆起;(2)水平位移发生在拱肩和拱腰处,水平位移量及变动幅度小于竖向位移;(3)随着弹性模量增大,各部位的竖向位移减小;拱肩、拱腰处水平位移减小,拱脚处水平位移无变化;(4)随着内摩擦角增大,拱顶、拱肩、拱腰处竖向位移减小,拱脚、隧底竖向位移增大;水平位移均减小,拱肩受影响最为显著;(5)随着粘聚力增大,竖向位移及水平位移均减小,拱腰受影响较为显著;(6)管棚注浆法对围岩变形有限制作用,增大管棚布设范围对拱顶竖向位移的控制效果更明显。

In order to explore the influence of surrounding rock parameters such as elastic modulus,internal friction and cohesion on the surrounding rock construction deformation of the tunnel and analyze the control effect of pipe shed layout on the deformation of surrounding rock,taking a highway tunnel project as the basis,the model is established by the Midas finite element software,and the following conclusions are obtained by the simulation calculation:(1)The vertical displacement occurs in all parts of the surrounding rock,settlement in the vault,spandrel and arch waist,and uplift at the arch foot and tunnel bottom;(2)The horizontal displacement occurs at the spandrel and the arch waist,and the horizontal displacement and the change amplitude are smaller than the vertical displacement;(3)With the increase of elastic modulus,the vertical displacement of each part decreases;the horizontal displacement at the spandrel and arch waist decreases,but the horizontal displacement at the arch foot does not change.(4)With the increase of internal friction angle,the vertical displacement at the vault,spandrel and arch waist decreases,and the vertical displacement at the arch foot and tunnel bottom increases.The horizontal displacement decreases,and the spandrel is most affected.(5)With the increase of cohesion,the vertical displacement and horizontal displacement decrease,and the arch waist is significantly affected.(6)The grouting method of the pipe shed has a limiting effect on the deformation of the surrounding rock,and the control effect of increasing the pipe shed layout range on the vertical displacement of the vault is more obvious.