时速300～350km高速铁路桥梁动力性能试验研究

Experimental Study on Dynamic Behaviors of Bridges for 300～350km·h^(-1) High Speed Railway

基于近年来在我国开展的高速铁路桥梁动力性能试验,对设计速度300～350km·h-1高速铁路常用跨度混凝土桥梁以及部分特殊结构桥梁的自振频率、刚度参数及梁体动力响应等实测结果进行分析。结果表明:高速铁路常用跨度简支梁和连续梁的实测自振频率和刚度均满足规范限值要求,且有一定余量,有进一步优化的空间;高速铁路常用跨度混凝土桥梁以及部分特殊结构桥梁的动力响应实测值均较小,能够满足动车组300～350km·h-1高速运行要求;连续等跨布置32m简支梁的周期不平顺效应不明显;常用跨度简支梁不会产生横向共振现象,但在特定车速下会产生竖向超谐共振;常用跨度连续梁和特殊结构桥梁的竖向自振频率与动车组在特定车速下的竖向强振频率接近时,梁体竖向动力响应增大。

Based on the experimental research in recent years on the dynamic behaviors of bridges for high- speed railway in China, the test results of concrete bridges with common spans and bridges with special structure used for high speed railway with the design speed of 300-350 km h-1 were analyzed, which in- cluded natural frequency, stiffness parameters and the dynamic response of beam. The findings indicate as follows. The tested natural frequency and stiffness parameters of simply supported beams and continuous beams with common spans can meet the requirements of relevant codes, still there is particular allowance and can be further optimized. The measured values for the dynamic responses of both concrete bridges with common spans and bridges with special structure are relatively small, which can meet the operation re- quirements of EMU with the speed of 300-350 km h-1. The periodic irregularity effects of 32 m simply supported box beams arranged with continuous equal spans are not obvious. Lateral resonance does not ap- pear for simply supported beams with common spans; however, vertical superharmonic resonance has ap- peared at particular speed. While the vertical forced vibration frequency of EMU at particular speed is close to the vertical natural frequency of continuous beams with common spans and bridges with special struc- ture, the vertical dynamic response of beam is amplified.