Owing to widespread applications of continuous welded rail (CWR) in high-speed railway bridges, the studies on the seismic response of high-speed railway simply-supported beam bridges (HSRSSBB) considering track constraint is of greatest importance. In order to ensure the high efficiency and high precision of calculations under the consideration of constraint of a long track system, based on the consideration of longitudinal constraint and beam-track interaction, an equivalent model for the HSRSSBB was established, which can simultaneously achieve high calculation efficiency and calculation precision. Also, the sensitivity for seismic response of the HSRSSBB had been proposed, and a judging formula to rapidly determine the bridge-subgrade longitudinal constraint range for the HSRSSBB was established. Finally, after an analysis of a large number of cases, the relationship between the equivalent boundary characteristics and the bridge-subgrade longitudinal constraint range was studied, indicating that the subgrade length of 90 m can be used as the reasonable subgrade length in the longitudinal seismic analysis for the HSRSSBB.

由于连续钢轨在高速铁路桥梁中的广泛应用，对考虑轨道约束的高速铁路简支梁桥（HSRSSBB）地震响应的研究尤为重要。为了确保在考虑长约束条件下的高效率和高计算精度的基础上，在考虑纵向约束和梁-轨道相互作用的基础上，建立了HSRSSBB的等效模型，可以同时获得较高的精度。计算效率和计算精度。此外，提出了HSRSSBB地震反应的敏感性，并建立了一个快速确定HSRSSBB桥梁路基纵向约束范围的判断公式。最后，