【摘要】 在城市地铁工程中,经常出现新建隧道施工近接既有隧道的情况,包括隧道水平、竖直和倾斜平行以及上下正交和斜交等,新隧道的掘进不可避免地对既有隧道产生影响。本文针对盾构法新建正交下穿隧道,以广州地铁3号线大塘-沥滘区间盾构隧道为背景,采用室内相似模型试验和三维有限元数值计算相结合的手段,引入横向和纵向等效刚度折减系数,对盾构隧道正交下穿施工所引起的既有隧道纵向变位、纵向附加轴力和弯矩、横向变形、横向附加轴力和弯矩进行深入研究,得到围岩条件、隧道净距、顶推力等因素作用下盾构隧道正交下穿施工所引起的既有隧道的变形和附加内力分布变化规律。更多还原

【Abstract】 In urban metro construction there often occurs the situation when newly-built tunnels pass adjacent to existing tunnels,including horizontal,vertical & inclined parallel tunnels,perpendicular overcross & undercross tunnels and inclined cross tunnels.Tunneling of the new tunnels has an inevitable impact on the existing tunnels.Against the background of the construction of the Datang-Lijiao section shield tunnel of Guangzhou Metro Line 3,and introducing in the lateral and longitudinal equivalent stiffness coefficients,the longitudinal displacement,longitudinal additional axis force & moment,lateral deformation,lateral additional axis force & moment of the existing tunnel induced by perpendicular undercross shield tunnel construction are studied by means of the laboratory similar model test and 3D FEM computation.The factors such as the surrounding soil,clear distance and advance force etc and their influence on the laws of distribution of the mentioned deformations and additional internal forces in perpendicular undercross shield tunneling are also discussed.更多还原