基于地基雷达的高铁简支箱梁运营性能检定

针对高铁桥梁运营性能参数传统测试方法存在的数据采集设备安装困难、数据传输不稳定、工作效率低等问题,运用地基雷达非接触、高精度、高频率测量技术,对京沪高铁31.5m预应力混凝土双线简支箱梁进行运营性能检定。结果表明:在动车组时速为300km以上、载客运行状态下,检测得到该桥梁体的自振频率为6.823Hz,挠跨比为1/7 150~1/9 450,梁端转角为0.33‰~0.43‰;单线运行条件下梁体竖向振幅为0.13mm,横向振幅为0.07mm;实测动力系数小于运营动力系数;基于地基雷达的检定结果与传统方法检定结果相吻合;简支箱梁的运行性能参数与相关规范规定的通常值相接近;采用地基雷达能够方便、快速、高效地检定出高铁桥梁的梁体自振频率、梁体跨中挠度、梁端转角、运营动力系数、跨中竖向振幅和横向振幅,为我国高铁简支箱梁运营性能检定提供了新的方法。

Verification of Operational Performance for Simply Supported Box Girder in High Speed Railway Based on GB-SAR

To solve such problems as difficulties in installing data acquisition equipment,unstable data transmission and low work efficiency existed in the traditional test methods for operational performance parameters in high speed railway bridges, using non-contact, high-precision and high-frequency measurement technology of ground-based radar to verify the operational performance of 31.5 mprestressed concrete double-line simply supported box girder for Beijing-Shanghai high speed railway.Results showed that when the speed of the EMU was more than 300 km·h-1 and was running with passengers,the natural frequency of the bridge was 6.823 Hz,the ratio of deflection to span was 1/7 150~1/9 450,the rotation angle at girder end was 0.33‰~0.43‰.The vertical amplitude of the beam body was 0.13 mm and the lateral amplitude was 0.07 mm under single-line running condition,and the measured dynamic coefficient was less than the operation dynamic coefficient.The verification results based on ground-based radar are consistent with those of traditional methods,and the operation performance parameters of simply supported box girder are close to the usual values stipulated by relevant specifications.Ground-based radar can easily,quickly and efficiently verify the natural vibration frequency,mid span deflection,beam end angle,operation dynamic coefficient,mid span vertical amplitude and lateral amplitude of high speed railway bridge,which provides a new method for the operational performance verification of simply supported box girder of high speed railway in China.