暗挖地铁车站侧穿特殊结构桥梁保护措施研究

北京地铁12号线安贞桥站侧穿安贞西桥和安贞东桥,受桥梁基础位置的制约,车站主体结构采用暗挖分离结构形式。邻近桥梁的下部结构形式为斜腿刚构,这种特殊的结构形式对差异沉降极为敏感且抵抗变形能力较差。基于车站与邻近桥梁相对位置关系以及桥梁结构特点,首先确定邻近桥梁基础的风险等级和变形控制指标,在此基础上,从车站主体结构建造方案、洞内超前注浆加固地层以及在地面设置隔离桩等角度探讨对邻近桥梁的保护措施,最后给出桥梁变形超过变形控制标准情况下的保护措施。

Protection Measures of Special Structural Bridge Affected by the Construction of Mined Metro Station Sideway

The Anzhenqiao Station of Beijing Metro Line 12 is near the Anzhen West Bridge and Anzhen East Bridge. Restricted by the location of the bridge foundation, the Anzhenqiao Station structure is designed as two separated tunnels. The substructure of the adjacent bridge is composed of a slant-legged rigid frame, which is sensitive to differential settlement and of poor resistance to deformation. Based on the position relationship between the station and the adjacent bridge and the structural characteristics of the bridge, the risk level and deformation control index of the adjacent bridge foundation were determined in this study. On this basis, the protection measures for the adjacent bridges are discussed from the perspectives of the construction scheme of the main structure, the grouting in advance to reinforce the strata, and the setting of isolated piles on the ground. Finally, emergency protection measures are introduced for the scenario where the bridge foundation defor-mation exceeds the deformation control standard.