中文摘要：

开展了行车条件下高速铁路CRTSⅡ型板式无砟轨道一桥梁系统的动力响应现场测试，测试CRH380A-001型列车以285～350km／h时速通过时无砟轨道-32m标准预应力混凝土简支粱的动力响应．通过现场采集与数据分析，得到了钢轨、轨道板、底座板、桥面板的竖横向加速度幅值，桥墩顶纵横向绝对位移．结果表明：结构各层加速度在列车时速达到295km／h左右时，急剧增大，之后顺速降低，出现陡波峰；车致振动加速度响应自钢轨-轨道板-底座板-桥面板，自上至下呈明显的递减趋势，振动衰减较为明显．此外，基于实测的梁体自振频率与阻尼比，分析了梁体动挠度的简化计算方法，计算结果与实测梁体动挠度较接近．实验结果可为改进数值分析模型、验证计算结果提供依据．

英文摘要：

A dynamic experiment for CRTSII slab ballastless track - bridge system under the train run- ning condition was carried out. The dynamic response of CRTS IT and standard 32m simply supported pres- tressed concrete box girders was measured under CRH380A-00t trains traveling at the speed of 285 to 350 km/h. Through the field collection and data analysis, the vertical and transverse acceleration amplitudes of the rail, track plate, base plate, and beam panel were obtained. The vertical and transverse absolute dis- placements of the pier top were also obtained. The results show that abrupt wave crests appear, as the ac- celeration of each structure increases fast and then reduces significantly when the train speed reaches about 295 km/h. At that time, the vehicle induced acceleration response of the rail-track plate-base plate-beam panel has a significant decline trend, and the vibration attenuation is relatively obvious. Furthermore, the simplified method for computing the dynamic deflection of a girder was analyzed based on the measured natural frequency and damping ratio of the girder, and the calculated values are close to the measured ones. The study results can provide the basis for improving the numerical analysis model and verifying the calculation results.