复杂水域三跨变截面钢箱梁顶推滑移技术研究

Research on Jacking and Sliding Construction Technology of Three Span Variable Cross-Section Steel Box Girder in Complex Waters

为解决复杂水域通航环境下大跨度变截面钢箱梁施工难题,结合绍兴鉴湖大桥辅桥(55+85+55)m三跨连续钢箱梁施工项目,分析了该项目顶推滑移施工的重难点;并从拼装平台及滑移支架设计、理论入土深度和DZJ-120型振动锤贯入度双目标控制、滑靴(获专利)限位装置设计、监控手段等方面进行了顶推滑移关键技术研究。施工实践表明:(1)采用创最大重量和最大截面高差的记录(总重近2000 t,截面高差达3 m)连续三跨变截面钢箱梁的顶推滑移施工技术,是成功的;(2)基于“m”法确定桩土作用,结合有限元方法和支架设计布置,方法可行;(3)理论入土深度和DZJ-120型振动锤贯入度双目标控制达到理想效果;(4)滑靴限位装置设计达到缩短顶推工期,减少对通航口及近接桥梁的影响。

In order to solve the construction problem of large-span variable cross-section steel box girders in complex water navigation environments,combined with the construction project of the auxiliary bridge(55+85+55)m three span continuous steel box girder of Shaoxing Jianhu Bridge,the key and difficult points of the project's pushing and sliding construction were analyzed;and key technologies for pushing and sliding were studied from the design of the assembly platform and sliding bracket,the theoretical depth of penetration and the dual target control of the DZJ-120 vibration hammer penetration,the design of the sliding shoe(patented)limit device,and monitoring methods.The construction practice has shown that:(1)the use of the pushing and sliding construction technology for continuous three span variable cross-section steel box girders with a record breaking maximum weight and maximum section height difference(total weight nearly 2000 t,section height difference up to 3 m)is successful.(2)Based on the“m”method to determine the pile soil interaction,combined with finite element method and support design layout,the method is feasible.(3)The dual objective control of theoretical penetration depth and DZJ-120 vibration hammer penetration has achieved ideal results.(4)The design of the sliding shoe limiting device aims to shorten the launching period and reduce the impact on navigation ports and adjacent bridges.