地铁隧道穿越既有桥梁安全风险评估及控制

 由于城市地铁建设的不确定性和桥梁结构的复杂性，导致城市地铁工程邻近桥梁施工安全风险的显著增加。针对地铁施工对邻近既有桥梁的安全影响问题，建立包含工前检测、工前评估、工中动态控制、工后评估及恢复等四个方面的既有桥梁安全风险评估及控制体系，即识别可能存在的风险，提出地铁施工过程中既有桥梁施工中的控制指标及控制标准，关键是既有桥梁所能承受的最大差异沉降量；综合应用注浆加固及主动顶升等措施，利用信息化手段实现既有桥梁在全过程中的安全性；通过对施工结束后施工数据的分析，对既有桥梁结构进行必要性评估及恢复。将该成果应用于北京地铁6号线穿越花园桥施工过程中，结果表明，穿越施工风险控制达到了预期的控制目标，实现了既有桥梁在隧道施工过程中的安全运营。

SAFETY RISK ASSESSMENT AND CONTROL OF EXISTING BRIDGE CROSSED BY TUNNEL CONSTRUCTION

Due to the uncertainty subway construction and complexity structure of bridge, safety risks on new subway crossing to existing bridge construction are significantly increased. For solving this security problem, safety risk assessment and control system including detection before construction，assessment before construction，dynamic control under construction，assessment and restoration after construction is proposed. Then possible risk is recognized. Control indexes and control standards under construction, especially the maximum differential settlement of existing bridge are put forward. Based on the application of grouting and active lifting measures, under the guarantee of information method，the security of existing bridge in the whole process is realized. According to the analysis of the data after construction，the necessary assessment and restoration after construction should be adopted. The achievement is applied in Line 6 Beijing Subway construction crossing to the garden bridge. According to the results analysis, the desired control goal has been achieved so that the existing bridge safely operation will has been realized during the whole construction.