涉航作业对地铁隧道结构安全影响分析

Analysis of the Impact of Navigation Operations on the Safety of Subway Tunnel Structures

运用定量及有限元计算分析了地铁保护区范围内涉航作业对地铁隧道结构安全影响。分析结果表明,航道疏浚养护工况下隧道抗浮系数大于1.1,卸载比小于0.2,满足规范要求;1000 t级沉船传递到隧道顶的荷载、日常护岸维护加固、码头堆载产生荷载均可控制在设计荷载20 kPa内;经有限元分析,船舶抛锚、靠离泊码头及锚地船舶停泊对隧道产生的变形均小于20 mm。上述航道作业对地铁隧道结构影响能满足轨道交通结构安全控制指标值要求。临近码头加固维修及拆除对城市轨道交通安全运营有较大影响,加固方法、桩基施工及拆除工艺需要严格控制,减小挤土效应,减小外部作业对隧道结构的影响。

Quantitative and finite element calculations are used to analyze the impact of navigation operations on the safety of subway tunnel structures within the subway protection zone.The analysis results show that the anti floating coefficient of the tunnel is greater than 1.1,and the unloading ratio is less than 0.2,which meets the requirements of the code;the load transferred from the 1000 t class sunken ship to the top of the tunnel,the daily revetment maintenance and reinforcement,and the load generated by wharf stacking can be controlled within 20 kPa;through the finite element analysis,the deformation of the tunnel caused by ship anchoring,berthing and berthing at anchorage is less than 20 mm.The above channel operations have little influence on the subway tunnel structure and can meet the requirements of rail transit structure safety control index value.The reinforcement,maintenance and demolition near the wharf have a great impact on the safe operation of urban rail transit,the reinforcement method,pile foundation construction and demolition technology should be strictly controlled to reduce the soil compaction effect and the influence of external operation on the tunnel structure.