轨道交通中长联大跨连续梁桥抗震设计分析

Seismic Design Analysis of Long Span and Long Unit Continuous Girder Bridges in Rail Transit

新建西安北—机场线跨越渭河主河槽,主桥采用(50+8×100+50)m预应力混凝土变高度连续梁,桥址处地震烈度高,特征周期长,采用双曲面球型摩擦摆减隔震支座+黏滞阻尼器共同作用的减隔震方案进行抗震设计,利用大型通用有限元程序Midas进行桥梁地震动态时程计算分析,结果表明固定墩受E1地震控制,活动墩受E3地震控制,采用的双曲面球型摩擦摆减隔震支座+黏滞阻尼器共同作用的减隔震方案对轨道交通中长联大跨连续梁抗震设计是合理的.

Newly-built railway from North Xi~ an to the airport crosses the main channel of the Weihe River,and the main bridge adopts prestressed-concrete variable-depth continuous beam and the main span is （50＋8;〈 100＋50） m. The seismic intensity of the bridge site is high and the characteristic period is long. The isolation scheme which combines the hyperboloid spherical fric- tion pendulum isolation bearing with viscous damper meets the requirement of seismic design. The dynamic time history analysis of the bridge is carried out by finite element program Midas. The results show that the designed isolation scheme is reasonable and can meet the specification requirement.