基于静动载试验的预制装配式T梁桥承载能力

为评价新建预制装配式桥梁的结构性能和工作状态，对遂德高速公路九龄岗大桥40 m T梁段进行单梁静载试验、全桥静动载试验以及有限元仿真分析。通过静载试验测试了单梁与成桥阶段控制截面的应变、挠度，并结合有限元计算结果对比分析，采用脉动试验和行车试验获得了桥梁的自振特性、不同行车速度下的动力效应和冲击效应。研究表明：单梁与全桥静载作用下结构应变及挠度校验系数均满足规范要求，卸载后相对残余应变及位移远小于规范规定的20 %，结构承载能力良好；边梁在各级加载下的挠度、应变值与荷载横向分布系数均大于中梁，总体上变形、应力分布较均匀，结构抗扭刚度与强度有一定安全储备；脉动试验实测阻尼比为1.139 %，小于规范规定的5 %，该桥动力特性良好，在结构体系振动过程中具有较好的能量耗散性能；行车试验中随着车速增加，结构动力效应越显著，动挠度、动应变与冲击系数有明显增大的趋势，实测冲击系数为0.065 ～ 0.133 ，表明该桥面平整度良好。

Research on bearing capacity of prefabricated T-beam bridge based on static and dynamic load test

In order to evaluate the structural performance and working state of the newly built prefabricated bridge, the single girder static load test, the whole bridge static and dynamic load test and the finite element simulation analysis were carried out on the 40 m T beam section of the Jiulinggang Bridge of Suide Expressway. Through the static load test, the strain and deflection of the control section of the single beam and the bridge stage were tested, and the finite element calculation results were compared and analyzed. The natural vibration characteristics of the bridge, the dynamic effect and the impact effect under different driving speeds were obtained by the pulsation test and the driving test. The research results show that, the structural strain and deflection calibration coefficients of single girder and full bridge under static load all meet the requirements of the specification, and the relative residual strain and displacement after unloading are far less than 20 % of the specification, and the structural bearing capacity is good. The deflection, strain value and load lateral distribution coefficient of the side beams at all levels of loading are all larger than those of the middle beams, and the overall deformation and stress distribution are relatively uniform, and the torsional stiffness and strength of the structure have a certain safety reserve. The measured damping ratio of the pulsation test is 1.139 %, which is less than 5 % specified in the specification, with good dynamic characteristics and good energy dissipation performance during the vibration of the structural system. In the driving test, with the increase of the vehicle speed, the dynamic effect of the structure is more obvious, and the dynamic deflection, dynamic strain and impact coefficient have a tendency to increase obviously, the measured impact coefficients range from 0.065 to 0.133, indicating that the bridge deck has good flatness.