半整体式全无缝桥梁研究

A study of fully jointless bridge-approach system with semi-integral abutment

针对国外常用的无缝桥梁中存在一个路与桥之间接缝处理的难题,提出一种新型的半整体式全无缝桥梁体系的设计新构思,即不仅取消全部的桥面伸缩缝,而且还取消了桥与路之间的接缝构造。新型半整体式全无缝桥梁体系中,主梁、搭板和接线路面三者相互连接和制约,梁体发生收缩变形时,通过搭板拉伸加筋接线路面板,相应地,梁体也受到了加筋接线路面的阻滞拉力作用;而温度上升时则反之。对这一新的结构体系进行深入系统的理论和构造研究,将桥和路作为整体进行受力分析和结构设计,推导了加筋接线路面在自身温度变化、干缩和梁体收缩共同作用下吸纳变形的计算公式,并由试验确定加筋接线路面板的裂缝宽度和裂缝间距的计算公式。通过实桥设计施工及后续多年运营监测,已证明这种新型全无缝桥梁是安全可行的,实测应变和变形也均在计算范围之内。

Conventional integral （or semi-integral） bridges do not involve deck joints, which overcome the difficulties related to bridge deck joints. The joints for dealing with deck thermal movements are shifted away from the bridge deck ends to the structure/road interface at the ends of the approach slabs. Therefore, the pavement expansion joint or pavement pressure relief joint still needs regular maintenance and may eventually cause local failure or bump. To solve such problems, a special fully jointless bridge-approach system with no expansion joint on the bridge deck and the approach pavement is developed. Successful applications for retrofit semi-integral bridges in the past three years have proven the effectiveness of the jointless approach pavement. Theoretical analysis, experiment and design of approachpavement reinforcement are also presented.