高烈度区非对称独塔斜拉桥的设计分析

Design analysis of Asymmetric Single-pylon Cable-stayed Bridge in High Intensity Area

摘要:

西藏日喀则市樟木镇樟木大桥为110 m+151 m+32 m非对称独塔混凝土斜拉桥，位于高烈度区。以此桥为背景，介绍桥梁的总体设计。索塔采用分离式塔柱，塔高136 m；主梁采用双主肋混凝土梁，梁宽13.1 m，梁高2.65 m；拉索立面采用扇形布置，全桥共布置68根，塔上索距为2.6 m，梁上标准索距为8 m，边跨现浇段索距加密为4 m。对桥梁进行静力分析和抗震分析，采用了抗拉球钢支座和纵向横向阻尼器等抗震措施。最后介绍了施工方案，主塔采用爬模法施工，主梁悬浇段采用悬臂浇筑法施工，边跨现浇段、中跨现浇段及辅助跨采用支架法施工。结果表明，该桥的各项指标均满足规范要求。

Abstract:

Zhangmu Bridge in Zhangmu Town, Shigatse City, Tibet is a (110+151+32)-m asymmetric single-pylon concrete cable-stayed bridge located in high intensity areas. Based on this bridge, the overall design of the bridge is introduced. The cable pylon is a separated pylon column with a pylon height of 136 m. The girder is a double-rib concrete girder with a girder width of 13.1 m and a girder height of 2.65 m. The stayed cable facade is a fan-shaped, and a total of 68 cables are arranged throughout the bridge. The cable spacing on the pylon is 2.6 m, the standard cable spacing on the girder is 8 m, and the cable spacing on the cast-in-place section of side span is encrypted to 4 m. The static analysis and seismic analysis of the bridge are carried out, and the seismic measures such as tensile spherical steel bearings and longitudinal and transverse dampers are adopted. Finally, the construction scheme is introduced. The main pylon is constructed by the climbing formwork method, and the cast-in-cantilever method is used for the cantilever casting section of the girder. The support method is used for the cast-in-place sections of the side span, the middle span and the auxiliary span. The results show that the indexes of the bridge meet the requirements of the specification.