山区高速桥墩计算长度分析及结构形式比选

包茂高速粤境段A1合同段位于云开山的东南端,相对高差较大,为典型山区高速公路.结合广东省高速公路设计标准化研究成果,桥梁上部普遍采用预制结构,下部根据墩高选择不同的结构形式.文中通过有限元模型,利用压杆弹性稳定理论,得出桥墩在各边界条件下的计算长度及偏心矩增大系数;在此基础上,针对35～ 45m墩高范围普遍采用的板式桥墩及双柱式桥墩,分析其施工及使用阶段最不利荷载工况,进行结构形式比选,优化结构设计.

Analysis of Calculation Length and Structure Comparison of Bridge Pier in Mountain Highway

Part of Bao-Mao highway which is located the southeast of Yun-kai Mountains in Guangdong is a typicalmountain highway. Combined with the design standardization of highway, prefabricated construction is widely usedin the superstructure of bridge and the structural style of bridge pier is adjusted by the height of pier. On the basis oftheory of elastic stability and finite element model, this paper obtains the calculation length and the enhancement coefficientof eccentric bending moment, and besides, this analytical method is employed to compare the columnar pierand plate pier which both are widely used in the height 35~45 m, to direct design optimization.