节段预制拼装桥梁耐久性设计要点研究

研究目的:在国内节段预制拼装桥梁正处于发展时期,这类桥梁有着自身的特殊性,其耐久性方面必须引起足够重视,特别是需要重点处理好节段拼缝和预应力体系的耐久性设计。结合国外有关预制拼装桥梁耐久性设计、施工措施及国内桥梁的设计实践经验,本文针对这类桥梁节段拼缝和预应力体系的耐久性设计,提出关键性技术建议,以供设计和施工时借鉴。研究结论:节间接缝的耐久性设计应注意合理设置节间缝的道数和位置,做好节间缝剪力键的构造设计,同时充分重视接缝环氧胶的性能指标要求。对于其预应力体系,应按全预应力体系进行设计,结构设计计算及预应力配束应符合节段预制拼装的技术特点,预应力管道灌浆应严格控制质量,有体外索设置时应注意减振和防腐处理。

Research on Key Points of Durability Design of Precast Segment Assembling Bridge

Research purposes: The construction technology of the precast segment assembling bridge is in the development period in China.As such kind of bridge has its own features,the more attention should be paid to the durability,especially the durabilities of the segment joints and pretressing system.Combining with the practices of durability design and construction measure for the precast segment assembling bridge at home and abroad,this paper offers the key technical advices on the durability design of the precast segment assembling bridge for providing the reference to the similar works. Research conclusions:In the durability design of the segment joint,it is important to set up the reasonable number and positions of segment joints and well make the structure design of the shear connector,and at the same time,the attention should be paid to the index requirement of the epoxy adhesive.If the bridge is of the prestressed structure,the full prestressing system should be adopted.The structure calculation and prestressing tendon adjustments should tally with the technical features of precast gegment assembling bridge.The grouting quality of pretressed pipe should be strictly controlled,and the attention should be paid to the shock absorption and anticorrosion of externally.