山区公路桥梁高性能板式减震橡胶支座振动台试验

Shaking Table Tests on High-Performance Isolation Rubber Bearing Isolated Highway Bridge in Mountainous Area

摘要:

为探究高性能板式减震橡胶支座对山区常见不等墩高中小跨径连续梁桥的隔震效果，对一座采用该类隔震支座隔震的、桥墩刚度不等的两跨连续梁桥简化模型进行了纵桥向振动台试验.采用多烈度多设防水准的人工波、Northridge地震波作为激励，分析各类地震下隔震模型的支座变形表现及结构关键位置响应的变化规律.试验结果表明该类支座的隔震效果可使主梁加速度相比台面减少达58%，且其翘曲滚动变形足以适应结构在9度E2地震作用下的墩梁相对位移，震后还可回复，无残余位移，可以用于此类山区公路桥的隔震.

关键词:桥梁; 减隔震; 振动台试验; 高性能板式减震橡胶支座; 不等墩高连续梁桥; 柔性加劲材料

Abstract:

To investigate the isolation effectiveness of high-performance isolation rubber bearing (HIRB) on the small-to-medium span girder bridges in mountainous areas, shaking table tests were conducted on a two-span continuous girder bridge model in longitudinal direction. The model had different pier stiffness and was isolated by HIRB. Artificial earthquake waves and Northridge waves with multi intensities were applied as input ground motions. By studying HIRB’s deforming performance and measured structural response under various excitations, it is found that HIRB could mitigate the girder acceleration by 58% at most compared with input peak ground acceleration (PGA) and could roll over stably to satisfy the relative displacement between girder and piers under E2 earthquakes of 9-degree intensity with no residual displacement. Test results indicate the feasibility and effectiveness of applying High-Performance Isolation Rubber Bearing in continuous girder bridges with different pier heights.

Key words:bridge; seismic isolation; shaking table test; high-performance isolation rubber bearing; continuous girder bridge with different piers heights; soft reinforcement