中文摘要：

多线叠交盾构隧道在地下空间内布置形式繁多，土体-隧道间相互作用机制复杂。针对多线叠交盾构垂直上穿、垂直下穿和上、下夹穿3种典型穿越施工形式，根据盾构隧道近距离施工的技术特点和控制要求，采用排液法重点分析了施工中因地层损失和开挖卸荷引起的地表沉降以及既有隧道纵向变形规律，并通过构建三维弹塑性有限元动态模型，与部分试验结果进行了对比验证。研究结果表明：上穿施工中，地表沉降较大，既有隧道均呈现上浮趋势；下穿施工时，地表沉降较小，既有隧道均呈现下沉趋势；先下后上穿越施工在各阶段引起的地表沉降变化均匀，最终地表沉降量相对较小；先上后下穿越施工时既有隧道变形曲线曲率大，既有隧道变形呈现反复震荡变化。成果可为类似多线叠交隧道工程的施工提供理论指导。

英文摘要：

Multi-line overlapping shield tunnel has a complex form in underground space layout. The interaction mechanism between tunnels and soil is very complex. The new tunnel caused ground settlement and made adverse effects when traversing the existing tunnels. The drainage method model test was applied according to the technical requirements of shield tunneling and control requirements of approaching construction. The ground surface subsidence and the existing tunnels longitudinal deformation caused by strata damage and excavation unloading are analyzed for three typical construction methods, above-crossing, under-crossing and above-under crossing. Finite element model was built to simulate the dynamic construction process of model test. The results show that ground settlement tunas to be larger, and the existing tunnels have an upward moving during the construction of up-crossing. While under-crossed, a smaller settlement with a tendency of subsidence is found in the existing tunnel. The under-crossing first and then above-crossing construction leads to a uniform variation in ground settlement during various construction stages, and the final settlement is relatively small. The above-crossing first and then under-crossing construction results in a great curvature in deformation curve of existing tunnel, and the deformation of existing tunnel fluctuates constantly. The research results can provide some theoretical basis and prophase guidance for similar projects in the future.