新建公路桥梁对既有铁路桥隧的影响分析

新建高速公路悬臂浇筑连续梁桥跨越地铁高架桥及铁路隧道时,在施工过程中存在较多安全隐患。如工程措施不当或高空坠物,对运营地铁高架桥造成影响,危及既有桥梁行车安全;新建桥梁桩基施工引起既有隧道沉降,若不均匀沉降过大,将导致既有隧道衬砌开裂,影响既有隧道衬砌结构安全和城轨交通安全运营。本文以跨地铁高架桥及城轨铁路隧道的高速公路桥梁工程为依托,对桥梁基础施工引起的既有隧道结构及围岩变形进行了数值模拟计算,并对桥梁上部结构施工存在的交叉影响进行了安全风险分析,可为同类工程安全评估及防护提供参考。

Analysis of Influence of Newly Constructed Highway Bridge on Existing Bridges and Tunnels

There are many hidden safety hazards in the construction of new expressw ay cantilever casting continuous girder bridge across metro viaduct and railway tunnel. For example,improper engineering measures or falling objects in high altitude will affect the operation of metro viaducts and endanger the safety of existing bridges.The construction of new bridge pile foundation will cause the settlement of existing tunnels.If the uneven settlement is too large,it will lead to the cracking of existing tunnel lining,which will affect the safety of existing tunnel lining structure and the safe operation of urban rail transit.Based on the highway bridge engineering across metro viaduct and urban rail tunnel,the deformations of existing tunnel structure and surrounding rock caused by bridge foundation construction were numerically simulated in this paper. The safety risk analysis of the cross-impact of bridge superstructure construction was carried out,which could provide reference for the safety assessment and protection of similar projects.