类矩形土压平衡盾构掘进引起的地层变形三维数值分析

Three-dimensional Numerical Analysis of Ground Deformation Induced by Quasi Rectangle EPB Shield Tunneling

以国内首例类矩形地铁盾构工程为背景,采用三维有限元软件ABAQUS建立了包含盾构机、管片和注浆层的三维模型,模拟计算类矩形盾构逐步掘进的全部过程,分析了隧道埋深为中埋条件下类矩形盾构掘进引起的地层变形,并对开挖面支撑压力及注浆材料性质对地表变形的影响进行了参数分析。研究结果表明:类矩形盾构地表沉降曲线类似Peck曲线,沉降槽宽度约30 m,但深层土体沉降呈"W"型;盾构掘进引起距隧道边缘约3.5 m处土体发生最大水平位移6.1 mm;施工中适当提高土舱压力,并采用凝结时间短、凝结后模量高的同步注浆材料,有利于控制地层变形。

Abstract：Taking the first project of quasi rectangle adopted three-dimensional finite element software subway shield tunnel as the research backgroun ABAQUS to build 3D simulation model, which d, this paper included the shield machine, segment and grouting layer. The step-by-step construction l^ocess of the quasi rectangle tunnel advance was simulated and calculated to analyze the ground deformation induced by the quasi rectangle shield tunneling under the condition of middle burial. The parameters of influence including face pressure and grouting material properties on ground surface deformation were studied. Results indicated that the curve of the surface subsidence induced by quasi rectangle shield tunneling was similar to Peck curve and the width of surface sub- sidence was about 30 m, while the layered settlement had the shape of the letter W. The maximum horizontal soil displacement induced by shield tunneling was 6.1mm at the point about 3.5 m away from the edge of tunnel. In- creasing the face pressure and selecting synchronous grouting materials with short initial setting time and high initial settina modulus was helpful to control the ground deformation.