连续刚构桥双肢薄壁高墩施工阶段单墩稳定性影响因素分析

Analysis of Stability Factors of Single Pier During the Construction of Double Limb Thin-walled High Piers in Continuous Rigid Frame Bridges

为解决大跨度连续刚构桥双肢薄壁高墩稳定性问题,以新站特大桥为工程背景,针对该桥最高双肢薄壁墩(墩高114 m),通过Midas/Civil软件建立空间有限元模型,进行了数值模拟稳定性分析;探讨了墩身混凝土强度,桥墩高度,墩身截面尺寸、截面空心率和系梁位置、数量等设计要素,对连续刚构桥的双肢薄壁墩单墩的线性稳定性影响。分析结果表明:在最高裸墩状态下,桥墩的稳定性主要由自重和施工荷载控制,顺桥向和横桥向的风荷载对高墩的稳定性影响很小;桥墩的高度、系梁设置的数量与位置对其稳定性具有显著的影响,而混凝土强度、墩身截面空心率、墩截面顺桥向宽度和横桥向宽度变化对其稳定性的影响相对较小。因此,在双肢薄壁高墩设计中应综合考虑这些影响因素,以确保墩体的稳定性。

In order to solve the stability problem of double-limb thin-walled high pier of long-span continuous rigid frame bridge,Xinzhan Bridge is taken as an example.Aiming at the highest double-limb thin-walled pier(pier height of 114 m)of the bridge,the spatial finite element model is established by Midas/Civil software to analyze the stability of numerical simulation;The influence of design factors such as concrete strength of pier body,pierheight,size of outer section of pier body,hollow ratio of section,position and quantity of tie beam on the linear stability are discussed.The results show that the stability of the pier is mainly controlled by self-weight and construction load,and the wind load in the longitudinal and transverse bridge directions have little effect on the stability of the high pier with the highest bare pier;The height of the pier,the number and location of the tie beam have significant impact on its stability,while the concrete strength,the hllow ratio of the pier section,the width of the pier section along the bridge and the width of the transverse bridge have relatively smaller impact.In the design of double-limb thin-walled high piers,these influencing factors should be considered comprehensively to ensure the stability of the pier.