新京航运河大桥抗震性能分析

Aseismic Performance Analysis of Great Bridge of Jinghang Canal

根据JTG/T B02-01—2008《公路桥梁抗震设计细则》,新京航运河大桥主墩高仅3.6 m,属于矮墩,其地震结构的频率很高,在E2的地震作用下混凝土又不允许出现塑性破环,因此,必须进行减隔振设计。该桥选用了在国内有过应用先例的E型钢弹塑性阻尼器作为减震设备。在地震发生时E型钢阻尼器发生弹塑性变形,从而将输入桥梁结构的大部分地震能量吸收掉,将上部结构传递至桥墩的地震力保持在一定的水平内,保证了桥墩和桩基的安全,达到减振的目的。

According to JTG/T B02-01—2008 Guidelines for Seismic Design of Highway Bridge,the main pier of Great Bridge of Jinghang Canal is only 3.6 m,belonging to the lower pier,which means its frequency of seismic structure is high.The concrete structure is not allowed to appear plastic destruction under the earthquake action of E2.Therefore,the design for reducing seismic effect should be considered.E-shape steel elastic/plastic damper is chosen for this bridge for it has been used once as the aseismatic instrument in China.During the earthquake,E-shape steel elastic/plastic damper can appear plastic destruction,which can absorb most amount of earthquake energy transferring the bridge structure and can sustain the force from superstructure to the pier steadily.The security of the piers is ensured as well as the pile foundations,achieving the aseismatic purpose.