曲线连续箱梁桥侧倾和支座脱空原因分析

Analysis onthe reason for overturning and bearing-disengaging of curved continuous box girder bridges

针对国内曲线连续箱梁桥近年出现的支座脱空甚至侧倾的事故,以钢筋混凝土曲线连续箱梁为对象,采取空间有限元方法,研究在重力、汽车荷载及梯度温度作用下的支座反力,分析汽车荷载对结构抗侧倾性能的影响及可能引起事故的主要原因。研究表明,梯度温度作用对曲线连续箱梁的支座反力有很大影响,而曲线连续箱梁是否发生侧倾不能简单由支座是否脱空来判断,必须进行空间计算才能确定结构整体的抗侧倾性能。

Focusing on the accidents that some curved continuous box girder bridges in our country disengaged from the bearings or even overturned in recent years,this paper selected the reinforced concrete curved continuous box girders as example,and analysed with spatial finite element method to research the support reactions of the structures,which were applied by the actions of the gravity,vehicle load and gradient temperature.Investigations were made on the effects of the structural anti-overturning behavior under the vehicle loads and analysis were made on the causes of the accidents.The research results show that the gradient temperature affect the support reactions greatly of the curved continuous box girders;the support reaction can not be used appropriately to judge the structural anti-overturning behavior,alternative method is the spatial calculation to determine the structural anti-overturning behavior.