包茂高速公路粤境段预制梁桥非标桥墩结构形式比选

Structural Comparison of Non-standard Bridge Pier for Bao-mao Expressway

包茂高速公路粤境段A1设计合同段位于云开山的东南端,相对高差较大,为典型的山区高速公路.结合我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.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.

Contract No. A1 of Bao-Mao Expressway is located at the southeast end of Yun-kai mountains, and is a typical mountainous expressway as with high relative height difference. Combined with the design standardization of highway, prefabricated construction has been widely used for the superstructure of bridge and the structural style of bridge pier has been determined by the height of the pier. On the basis of theory of elastic stability and finite element model, in this paper, the calculation length and the enhancement coefficient of eccentric bending moment for piers under limiting conditions have been obtained. Furthermore, as for double-columns pier and plate pier which have been widely used for piers with a height between 35m and 45m, the most unfavorable load conditions for construction and operation have been analyzed, and structural types have been compared and determined, so structural design optimization has been accomplished.