临沂南京路沂河大桥主桥设计

临沂南京路沂河大桥位于8度强震区且跨越断裂带,主桥采用飞雁式异形拱桥与V形墩结合的组合体系,采用大吨位摩擦式减隔震支座,以提高结构抗震性能。主桥两侧(30.3+34.2)m采用预应力混凝土连续梁;中间(135.5+135.5)m为飞雁式异形拱桥,拱桥采用双边箱钢-混叠合梁,主拱采用矩形钢箱变截面拱肋,拱肋轴线为异形偏态拱轴线,不设风撑,拱梁固结,梁端设水平系杆平衡水平推力。下部边、中V形墩均采用大悬挑箱形截面混凝土结构,群桩基础。大桥采用先梁后拱的施工顺序,叠合梁采用多点平衡顶推施工,拱肋采用桥位少支架大节段拼装施工。

Design of Main Bridge of Yihe River Bridge on Nanjing Road in Linyi

The Yihe River Bridge on Nanjing Road in Linyi is located in the seismic area of 8 degree intensity and crosses a fault zone.The main bridge is a composite system formed of the flying wild goose shaped arch bridge and V-shaped piers.Large-tonnage frictional seismic mitigation and isolation bearings are installed to improve the anti-seismic performance of the structure.Two end parts of the main bridge,each with two spans of 30.3 m and 34.2 m,consist of prestressed concrete continuous beams,the central part that incorporates two spans of 135.5 m and 135.5 m is an irregular flying wild goose shaped arch bridge with deck formed of two steel edge boxes and concrete slabs.The main arch ring is a steel box arch structure with variable rectangular cross section revealing an irregular skew axial line.No wind bracings are installed on the arch ring,the arch and the deck are fixed,and horizontal ties are added to the ends of the deck to balance the horizontal thrust.The side and intermediate V-shaped piers are all the concrete box structures with long cantilevers,standing on grouped-pile foundations.The deck was constructed before the installation of the arch,and the composite beams were constructed by the multi-point balanced incremental launching method,and the arch ring was assembled from large sections without scaffoldings.