无背索曲塔曲梁斜拉桥施工稳定性分析

Analysis on Cable-Stayed Bridge with Curved Tower without Back Cable

以某一无背索曲塔曲梁斜拉桥为分析对象,针对桥梁结构特征,采用结构整体静力有限元分析桥梁极限状态及施工关键节点的整体与局部结构静力性能和动力特性,获得桥梁稳定性特征。研究结果表明:极限承载力作用下,桥塔混凝土、桥塔钢板、钢箱梁、边跨混凝土梁应力范围均满足施工标准;恒载作用下,索塔混凝土最大竖向压应力出现在内索塔与墩底连接处,在内塔底部出现最小压应力,主梁最大竖向变形出现在梁顶端位置;活载和风荷载作用下,外索塔在顺桥向荷载下产生最大变形,内塔底部产生局部最大拉应力;连接索塔削弱薄塔处顺桥向和横桥向最大拉应力均较大,因此,在设计施工中需要对该削弱薄塔区进行局部加强,避免出现结构失稳性破坏。

taking a cable-stayed bridge with curved tower without back cable as the analysis object,according to the structural characteristics of the bridge,the ultimate state of the bridge and the static and dynamic characteristics of the whole and local structures of the key nodes are analyzed by using the structural static finite element method.The characteristics of bridge stability are obtained.The results show that under the action of ultimate bearing capacity,the stress range of concrete,steel plate,steel box girder and side span concrete beam of bridge tower meets the construction standard.Under the action of dead load,the maximum vertical connection between the inner cable tower and the pier bottom appears in the concrete of the cable tower,the minimum compressive stress appears at the inside tower bottom,the maximum vertical deformation of the main beam appears at the top of the beam,and the live load and wind load appear.Under the action of the external cable tower,the maximum deformation is produced under the load of the bridge,and the local maximum tensile stress is produced at the bottom of the inner tower.The maximum tensile stress along the bridge and the transverse bridge in the connection tower is large,so it is necessary to strengthen the weakening area in the design and construction to avoid the unstable damage of the structure.