大型陆上沉井封底施工技术  

Bottom Sealing Technique for Large Scale Onshore Caisson

作　　者：胡才春[1] 贾雷刚[1] 

机构地区：[1]中交第二航务工程局有限公司,湖北武汉430040

出　　处：《世界桥梁》2012年第5期32-36,共5页World Bridges

摘　　要：大型陆上沉井具有下沉深度深、平面尺寸大、封底混凝土方量多等特点,为了有效保证封底施工质量,确保封底效果,马鞍山长江公路大桥北锚碇沉井封底施工时,通过对竖向分层封底、回填砂封堵分区隔墙封底、混凝土封堵分区隔墙封底3种工艺的对比,选择了较为合适的混凝土封堵分区隔墙封底方案。该方案首层沿分区隔墙浇筑封底混凝土,将分区隔墙与基底间空隙封堵,形成可靠挡墙使沉井形成四大一小5个分区,之后逐区域浇筑封底混凝土。在混凝土浇筑过程中,通过技术创新,减少了现场操作流程,降低了施工难度,施工时间短,经验收沉井封底质量良好。The large scale onshore caisson is characterized by its great sinking depth, large plane dimension and large amount of concrete consumed for bottom sealing. In the bottom sealing Construction for the caisson of the north anchorage of the Maanshan Changjiang River Highway Bridge, the three techniques of vertically-layed bottom sealing, using backfilling sand to block up the partition walls and using concrete to block up the partition walls were compared, finally, the bottom sealing technique of using concrete to block up the partition walls was adopted. The specific construction sequence was as follows, to cast the bottom sealing concrete along the partition walls for the first layer sealing, then, to block up the space between the partition walls and the base to form reliable retaining walls which would divide the caisson into 4 big and 1 small division zones and then to cast the bottom sealing concrete zone by zone. Through technique innovation, the field operation procedure was simplified, the construction difficulty was lowered and the construction time was also shortened. The final acceptance proves that the quality of the bottom sealing construction of the caisson is good.

关 键 词：马鞍山长江公路大桥 锚碇 沉井 分区隔墙 封底施工 

分 类 号：U445.557[建筑科学—桥梁与隧道工程]