程力

摘要：为研究大跨度钢管混凝土拱桥动力特性，以沈阳市浑河长青大桥为工程案例，对其进行了脉动试验测试和强迫振动试验，建立了有限元计算模型，将计算结果与实测数据进行了对比，二者吻合良好;并针对改善桥面系刚度提出了四种加固方案，研究了四种加固方案对结构动力性能的改善作用。通过对比得出了钢管混凝土拱桥最适宜采用的加固改造方案，对类似桥梁加固改造起到了指导、参考作用。

关键词：钢管混凝土拱桥;动力性能;加固方案;自改

Dynamic Performance Test and Reinforcement Scheme research of Long-Span Concrete Filled Steel Tubular Arch Bridge

Cheng Li

（China Railway 11^thBureau Group Fifth Engineering Co. Ltd.，Chongqing  400037，China）

Abstract：In order to investigate the dynamic characteristics of long-span concrete filled steel tubular arch bridge，this paper taking Chang-qing bridge in Shenyang as an engineering case，pulsating test and forced vibration test was done，the finite element calculation model was set up，the calculated results are compared with the measured data in good agreement. And four reinforcement schemes are proposed to improve the stiffness of bridge deck system，the improvement effect of four reinforcement schemes on the dynamic performance of the structure is studied in this paper.Through comparison，the most suitable reinforcement scheme is obtained.It has played a guiding and reference role in the reinforcement and reconstruction of similar bridges.

Key words：concrete filled steel tubular arch bridge;dynamic performance;reinforcement scheme;natural frequency;impact coefficient

1  前言

我國在上世纪九十年代至本世纪初建造了大量钢管混凝土拱桥^[1]，但其理论研究却远远滞后于工程实践。这些早期建成的钢管混凝土拱桥在常年运营过程中，开始逐渐暴露出诸如管内混凝土脱空^[2]不能与钢管协同受力、吊杆与系杆的锈蚀、疲劳等问题，尤其是采用悬吊体系的钢管混凝土拱桥桥面系整体刚度差，在移动车辆作用下桥面变形和振动大、桥面铺装使用寿命短的问题特别突出^[3]。本文以沈阳市浑河长青大桥为例，对其进行动力性能测试^[4]，并针对性地提出改造加固方案^[5，6]，以期类似工程参考。

2  工程背景

浑河长青大桥位于沈阳市东南部，是沈阳城区重要的交通要道，于1997年7月竣工通车，运营至今已二十余年。其主桥为三孔中承式钢管混凝土拱桥，净跨径为120m+140m+120m，南北边孔各为净跨径50m的空腹式钢筋混凝土肋拱桥，桥梁全长630m，桥宽32.5m。主孔计算跨径143.666m，计算矢高35.017m，矢跨比为1/4.103;边孔计算跨径123.223m，计算矢高26.488m，矢跨比为1/4.652。……