简介：钻爆法隧道穿越新建既有双连拱隧道结构,下穿隧道为大跨度隧道,高度大、埋深较深,且在穿越既有隧道时,不能影响其安全运营和造成结构破坏,施工难度大、风险高.采用有限元软件Midas GTS NX对钻爆法隧道下穿既有隧道的变形和受力情况进行数值模拟计算,并研究了下穿施工前对上方隧道间地层采用大管棚和锚杆联合加固产生的效果.研究表明:未加固时,施工侧隧道结构的沉降要大于另一侧,呈现出"一峰二谷"变形形状,既有隧道上下部极易发生结构破坏.采用大管棚及锚杆联合加固,有效地转移了应力集中现象,降低了结构破坏风险,并且既有隧道沉降量仅为前者变化量的 1/1.83,在控制标准以内.Abstract：The drilling and blasting tunnel crosses the newly built existing double-arch tunnel structure.The subway is a large span tunnel,with a large height and deep burial,and when crossing the existing tunnel,it cannot affect its safe operation and structural damage,the construction is difficult.A numerical simulation was carried out using the finite element software Midas GTS NX to calculate the deformation and stresses of a drilling and blasting tunnel underpassing an existing tunnel,and to study the effect of the combined reinforcement of the inter-tunnel strata above using large pipe sheds and anchors before the underpass construction.Studies have shown that the settlement of the tunnel structure on the co..