福州马尾大桥主桥设计关键技术

Key Techniques for Design of Main Bridge of Mawei Bridge in Fuzhou

福州马尾大桥主桥为跨径布置(71+83+123.5+240+123.5+83+71)m的连续箱梁桥,结合该桥长联、大跨、多跨等特点,对其设计关键技术进行研究。为降低梁体自重,该桥主梁采用钢—混混合梁(跨中设置96m长的钢箱梁),同时主梁根部采用空腹式箱梁结构。为降低桥梁的地震响应,14号、15号主墩布置摩擦摆球型支座,其他桥墩均布置摩擦摆柱面支座。为使主梁V撑上、下弦与整体主梁间的传力平顺自然,采用"V叉挑板式"角隅节点。为适应梁式桥的综合传力要求,钢-混结合段采用填充混凝土后承压板式构造。通过配置体外预应力实现对主跨跨中下挠的主动控制。

The main bridge of Mawei Bridge in Fuzhou is a continuous box girder bridge with the span arrangement （71＋83＋123.5＋240＋123.5＋83＋71） m. In the light of the characteris tics of the bridge＇s long unit, long span and multi span, the key techniques for design of the bridge were studied. To reduce the dead weight of the girder, steel concrete hybrid girder （96 m steel box girder set in mid span）was adopted in the main girder of the bridge, and the open-web box girder structure was adopted at the root of the main girder. To reduce the seismic response of the bridge, friction pendulum spherical bearings were arranged on the top of No. 14 and 15 main piers, and friction pendulum cylindrical bearings were placed on the top of the other piers. To make the force transfer between upper, lower chords of V braces and the whole main girder smoothly and naturally, the ＂V fork plate type＂ cube corner joint was adopted. To meet the comprehensive transmis sion requirements of beam bridge, the steel concrete joint section was constructed by filling con crete and rear bearing plate. Through the configuration of external prestress, the active control of the middle span deflection of the main span was realized.