为科学、安全、经济地确定蜀安隧道工程方案，采用资料调研、工程类比、经验总结等方法，对施工工法、纵断面设计、横断面布置、施工组织等总体设计方案和盾构选型与配置、超深竖井盾构高效始发等工程关键技术进行研究，得出以下主要结论： 1）城区铁路隧道施工工法应结合地质条件、建设环境条件和工期等因素综合比选，有条件时宜优先选择安全性高、环境影响小、施工进度快的盾构法； 2）盾构隧道主要穿越弱渗透性泥岩地层，建议选择土压平衡盾构，局部强透水地层采用地表降水+双闸门螺旋机+改良剂注入口措施解决； 3）通过优化刀盘刀具布置、加强管片连接刚度、同步双液注浆等措施，解决泥岩地层盾构结泥饼、管片上浮难题； 4）采用盾构井设置矿山法前导洞实现盾构“大分体”始发，解决超深竖井两端均接盾构区间条件下盾构的高效始发难题。
The construction methods,
longitudinal profile, cross-section
layout, construction organization, shield type selection, and shield launching
in ultra-deep shaft of the Shu′an
tunnel are comprehensively analyzed using data research, engineering analogy,
and experience summary methods. Findings are as follows: (1) The construction
methods for urban railway tunnels should be based on a comprehensive comparison
of geological conditions, construction environmental conditions, and
construction duration. Shield method is a priority when there are applying
conditions due to its high safety, minimal environmental impact, and fast
construction progress. (2) When tunnels primarily pass through weakly permeable
mudstone strata, the earth pressure balance shield is recommended. For locally
highly permeable strata, measures such as surface dewatering, double-gate screw conveyor, and injection ports for modifiers could be
adopted. (3) The phenomena of mud cake on cutterhead and segment floating can
be avoided by optimizing the arrangement of cutting tools on cutterhead,
enhancing the connection stiffness of the segments, and adopting synchronous
dual-component grouting. (4) An advance pilot tunnel by
mining method for shield launching shaft can realize high efficiency separate
launching of shield.
