为解决在城市复杂环境下，区间暗挖隧道在砂卵石地层中穿越桥梁、道路、管线和废弃人防等建（构）筑物等施工难题，以北京地铁4号线工程西单—灵境胡同区间隧道暗挖施工为例，采用对风险进行识别、分析、评价和应对的方法。施工中对天桥桩基进行托换，并对桩基周围土体进行注浆加固；对隧道初期支护施工中的格栅间距、超前小导管、格栅连接板等进行优化调整，并增设锁脚锚管；对侵入隧道内的废弃护坡桩及人防进行破除及局部加固处理等措施，使暗挖隧道安全、顺利穿越各种危险源。施工效果充分证明： 在北京地区砂卵石地层条件下，做好暗挖施工风险的分析，制定有效的应对措施，按照“先加固、后穿越”原则，遵循“管超前、严注浆、短开挖、强支护、早封闭、勤量测”的方针，对施工及设计方案进行动态管理、针对性优化，保证注浆加固效果，可以有效控制施工风险，确保暗挖施工安全、顺利地进行。

XidanLingjing Bystreet section of Beijing Metro, which is constructed by mining method, crosses underneath overpasses, roads, utility lines and air defense works. The risks in the construction of the tunnel are identified, analyzed, assessed and coped with. The pile foundations of the overpass are underpinned and the ground around the pile foundations is reinforced by grouting. The spacing of the lattice girders, the advance small duct and the connection plate of the lattice girders are optimized and foot locking bolts are added. The deserted slope protection piles and air defense works that interfere into the tunnel are broken and consolidated. In the end, the risks have been brought under effective control and the tunnel has been completed successfully.