装配式简支T梁桥静动载试验与评定研究

Static and Dynamic Load Test and Evaluation of a Fabricated Simply Supported T-beam Bridge

为了完善装配式预应力混凝土T梁桥性能检测评定方法,基于某公路简支T梁桥开展了单梁静载试验、全桥静动载试验以及有限元仿真分析。基于静载试验分别获得了单梁以及全桥各控制截面的应变与挠度校验系数,基于环境脉动数据识别得到了桥梁的自振频率与振型,并分别和有限元结果进行对比分析,基于跳车激励试验数据获得的自由衰减振动数据识别得到桥梁结构的阻尼比。研究表明:单梁与全桥控制截面实测应变值、挠度值均小于相应理论计算值;静载试验荷载效率相同条件下,全桥(成桥阶段)的挠度校验系数小于相应单梁;综合桥梁挠度横向分布系数和竖向振型能更全面地评估装配式T梁桥横向受力性能;相对基于环境脉动试验的半功率带宽法,基于跳车激振试验的自由衰减振动法可更为准确地识别桥梁的阻尼比。

In order to improve the inspection and evaluation method of the fabricated T-beam bridge,the static load test of a single T beam,the static and dynamic load test of a simply supported T-beam bridge as well as the finite element analysis of the T beam and the T-beam bridge were carried out.The strain and deflection of the main control sections of the single beam and the whole bridge were obtained by static load test,and the natural frequency and vibration mode of the bridge were identified through environmental vibration,which were then compared with theoretical values obtained by the finite element analysis.The damping ratio of the bridge was derived by fitting the data of the damped free vibration curve.Results show that experimental strain and deflection of the control section is less than the theoretical value.Under the same load efficiency ratio,the structural verification coefficient of the whole bridge(finished stage)is less than that of the single beam.Transverse connection performance is evaluated preferably by considering simultaneously transverse distribution coefficient and vertical vibration mode.Compared with half-power bandwidth method based on ambient vibration test,the damped free vibration method based on vehicle jumping test can identify damping ratio accurately.