铁路简支梁桥桥台承受列车制动力的计算分析

铁路桥台是桥梁和路基之间过渡的结构物,列车制动力通过桥台进行传递,其传递的机理和数值大小对桥台设计意义重大。笔者首次应用桥墩线刚度概念,把长钢轨力传到路基或更多的桥跨上,目的在于增加桥墩台抵抗长钢轨力的能力,以减小每个墩台的长钢轨力。应用结构分析的伪动力法,对不同跨度、不同长度的铁路简支梁桥墩台承受制动力进行大量计算;确定了16 m,24 m及32 m跨度桥梁的桥墩台可能承受的最大制动力,并与试验结果进行对比分析;研究了桥台传递列车制动力的机理,为确定简支梁桥的墩台制动力设计值提供了理论基础。通过分析制动力作用下的桥台安全性问题及措施,提出了列车制动力率取0.2和有效制动力率取0.15比较合理的数值,以确保列车运营的可靠与安全。

Calculation Analysis of Train Braking Force on Abutment of Simple Supported Railway Bridges

Bridge abutment is the transition structure of the bridge and the sub-grade, through which the train braking force is transferred. The mechanics and numerical value transferred are significant in the design of the bridge abutment. For the first time using the conception of linear sdffness of bridge pier, the force of long steel rail is delivered to the sub-grade and even more balks aiming at strengthening the resisting ability of bridge pier and abutment to reduce the Wessure on single bridge pier and abutment. Ntraerous calculations are carried out for simple supported railway bridges with different spans and different bridge lengths using pseudo-dynamic structure analysis method. The maximum braking forces possibly exerting on abutments of bridges with spans of 16, 24 and 32 meters are determined and ccrnpared with the test results, providing a theoretieal basis to delimit the braking foree. It is on this basis that calculation and analysis are also presented for the safety of abutments under the action of braking load. It is believed that when the braking force ratio is 0.2 and the efficiency braking force ratio is 0.15, the reliability and safety of train operation could be assured.