独柱混凝土曲线连续梁桥抗倾覆稳定性研究

Analysis of Anti-overturning Stability of Curved Concrete Continuous Beam Bridge with Single-Columned Piers

为了对既有公路混凝土曲线连续梁桥的横向稳定安全性进行评估,以中间墩采用独柱单支座支承的曲线连续梁桥为对象,基于安全系数法,定义抵抗倾覆的稳定力矩与产生倾覆作用的力矩的比值为抗倾覆稳定系数,计算曲线连续梁桥在自重和汽车荷载作用下的抗倾覆稳定系数并进行分析。结果表明:中间墩采用独柱支座支撑的曲线连续梁桥的抗倾覆稳定系数值与曲线半径不是单调递增或单调递减的关系,存在最不利曲线半径;在最不利曲线半径附近范围内,中间墩采用独柱单支座支撑桥梁的抗倾覆安全富余度很小甚至不足;直线桥的抗倾覆稳定性远高于曲线梁桥,曲线梁桥的抗倾覆稳定性与中间墩支撑形式有关。中间墩单支座外偏布置或改为双支座可提高曲线梁桥的抗倾覆稳定性。

To evaluate the transverse stability safety of existing highway curved concrete continuous beam bridge,the curved continuous beam bridge supported by single bearings on the single-columned piers is taken as the study subject.Based on the safety coefficient method,the ratio of stability moment resisting overturning and the moment inducing overturning effect is specified as the anti-overturning stability coefficient.The anti-overturning stability coefficients of curved continuous beam bridge under the effect of self weight and vehicle loads were calculated and analyzed.The results show that the relation between the anti-overturning stability coefficient and the curvature radius of the curved continuous beam bridge supported by single bearings on single-columned piers does not exhibit monotonously progressive increase or decrease,containing the most unfavorable curvature radius.In the vicinity of the most unfavorable curvature radius,the anti-overturning safety margin of the bridge of this type is small or even insufficient.The anti-overturning stability of the straight bridge is far higher than that of the curved beam bridge,and the anti-overturning stability of the curved beam bridge is related to the supporting form of the central pier.When the single bearing on the central pier is installed a little outward,or changed to be double bearings,the anti-overturning stability of the curved beam bridge can be improved.