【摘要】 随着扩建改造桥梁的逐渐增多及地震对桥梁结构危害严重性的增加,扩建改造桥梁的抗震性能越来越引起人们的关注。以京沪高速上的新徐海公路分离式立交桥为依托工程,分别对主梁连接、盖梁分离和主梁、盖梁都连接两种扩建方式桥梁的地震响应进行对比分析。结果表明:扩建改造后桥梁的自振周期略小于原桥,并伴随比原桥明显的主梁扭转;地震反应总体上小于原桥,并且主盖梁均连接的方案基本小于只有主梁连接的方案,更能降低地震反应;扩建改造后桥梁横向地震反应相对较复杂,并且不同的扩建改造方案对支座的影响比对桥墩的影响要小;扩建改造部分桥梁对原桥的影响程度与原桥本身的结构形式及连接方式具有较大的关系。更多还原

【Abstract】 With the gradual increasing of bridge expansion and reconstruction and serious damages to bridge structures under earthquake,the seismic performance of expansion and transformation bridge are increasingly focued. Taking the Xin Xuhai separated interchange bridge of Beijing-Shanghai expressway as the engineering background,the seismic response analysis about two types of bridge expansion and reconstruction is carried out,such as only the connection of two main girders and both the connection of the two main girders and two bent caps. The results show the natural vibration period of the expansion and reconstruction bridge is slightly smaller than the original,and the main girder reverses more obviously. Seismic response of expansion and reconstruction bridge is less than the original generally,besides,the latter type can reduce more seismic response than the former. Transverse seismic response of expansion and reconstruction bridge is relatively complex,and different expansion reconstruction schemes give less influence on bearing than the pier. The effect of part of expansion bridge to the original is related to the structure of the original bridge itself and the connection mode.更多还原