铁路重力式桥墩墩底局部加密纵筋高度研究

Height of dense longitudinal reinforcement at the bottom of railway gravity bridge piers

为研究墩底加密纵筋高度对铁路重力式桥墩抗震性能的影响,提出加密纵筋高度的确定原则,推导纵筋加密高度计算公式。设计5个不同加密纵筋类型的桥墩,通过数值分析研究桥墩的滞回曲线和骨架曲线,对比分析墩底加密纵筋后桥墩的抗震性能。研究结果表明:墩底局部加密纵向钢筋可有效提高桥墩的承载能力;桥墩抗震设计验算时截面配筋率可取墩底纵筋加密后的截面配筋率;数值分析结果验证纵筋加密高度计算公式的合理性。研究成果可为铁路重力式桥墩抗震设计提供有价值的参考。

To study the influence of the height of dense longitudinal reinforcement on the seismic performance of railway gravity bridge piers,the principle of determining the height of longitudinal reinforcement at the bottom of bridge pier was proposed and the formula of reinforcement height was deduced.Through numerical analysis,the hysteretic curve and skeleton curve of the pier were studied,and the seismic performance of pier after adding longitudinal reinforcement at the pier bottom was compared and analyzed.The results show that the horizontal bearing capacity of the pier can be effectively improved by increasing the amount of longitudinal reinforcement at the pier bottom.The reinforcement ratio of section after increasing the longitudinal reinforcement at the pier bottom can be adopted when checking the seismic design of pier.The rationality of the formula was also verified by the numerical analysis results.The research results can provide a valuable reference for the seismic design of railway gravity piers.