双圆盾构(DOT)隧道的地表沉降分析

分析了双圆盾构隧道的特点以及地表沉降的影响因素和不同计算方法.测试分析表明:双圆盾构隧道与圆形盾构隧道相比,双圆盾构隧道具有占用地下空间小、隧道断面形式多样化、切削面平衡操作简单、掘削土量少等优点;而隧道几何形状和埋深,土体性质的施工扰动,隧道衬砌的变形,盾构推进的平衡压力、姿态,同步注浆等是影响地表沉降的主要因素;最后得出双圆盾构隧道地表沉降与圆形盾构隧道具有相同的机理,但沉降值较大;双圆盾构隧道地表沉降槽的形态可以用正态函数表示,但最大沉降并不一定产生在隧道中心点.

Analysis of surface settlement induced by DOT shield tunnel

An analysis was made of the characteristics of DOT(double-o-tube) shield tunnels,the influencing factors on the surface settlement and its calculation methods.Testing analysis shows that,as compared with the circular shield tunnel,the DOT shield tunnel is of some advantages,such as the low underground spatial occupancy,the diversification of tunnel cross-sections,the simple operation to ensure the balance of cutting faces,and the less soil excavation,and that the geometric shape and embedded depth of the shield tunnel,the construction interferences to soil property,the deformation of tunnel liners,the equilibrium pressure and form of the shield during the pushing process,and the synchronous grouting technique are the main factors influencing the surface settlement.Finally,it is concluded that the surface settlement induced by DOT shield tunnel is of the same mechanism with that by the circular shield tunnel,but the surface settlement induced by DOT shield tunnel is relatively large,and that the shape of settlement troughs induced by DOT shield tunnel can be expressed with the normal distribution function,but the maximum settlement does not always occur at the center of the tunnel.