汶川地震中斜交连续梁桥震害机理研究

汶川地震中,斜交桥区别于直桥的典型震害现象为主梁的面内刚体转动.为研究其震害机理,以2跨及3跨预应力混凝土斜交连续梁桥为研究对象,建立数值分析模型,分析碰撞效应和结构偏心效应对主梁转角的影响.分析结果表明,斜交连续梁桥在地震作用下导致梁体面内刚体转动的主要原因是梁体与桥台或桥联间的碰撞效应与结构偏心效应.

Research on Mechanism of Earthquake Damage to Skew Continuous Girder Bridges in Wenchuan Earthquake

In Wenchuan earthquake,a typical phenomenon of earthquake damage of skew bridges different from straight bridges is in-plane rotation of rigid body of girder.In order to study the mechanism of earthquake damage,this paper,with 2-span and 3-span prestressed concrete skew continuous girder bridges as objects of study,establishes numerical analysis model to analyze influences of collision effect and structure eccentric effect on turn angle of girder.The analysis results show that main reasons for in-plane rotation of rigid body of girder of skew continuous girder bridges under the effect of earthquake are collision effect and structure eccentric effect between girder and abutment or bridging.