基于原位激振试验的高速铁路路基动力特性研究  

Research on Dynamic Characteristics of High-speed Railway Subgrade Based on In-situ Excitation Tests

作　　者：杨长卫[1] 岳茂 张良[1] 苏珂 蔡德钩 张先军 YANG Changwei;YUE Mao;ZHANG Liang;SU Ke;CAI Degou;ZHANG Xianjun(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Postgraduate Department,China Academy of Railway Sciences,Beijing 100081,China;Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;Engineering Management Center,China State Railway Group Co.,Ltd.,Beijing 100844,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中国铁道科学研究院研究生部,北京100081 [3]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [4]中国国家铁路集团有限公司工程管理中心,北京100844

出　　处：《铁道学报》2025年第4期133-140,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(42202324);四川省交通运输科技项目(2023-A-03);四川省区域创新合作(2024YFHZ0121)。

摘　　要：高速铁路路基在长期循环荷载作用下的动力稳定性十分关键,原位激振试验对研究路基的动力特性具有独特优势。依托京雄城际铁路固安东站工点开展原位激振试验,对路基结构随激振频率、扭力变化下动力响应特征进行研究,同时开展扫频试验,用于关注路基不同位置处自振频率、动剪切模量比与阻尼比的演变规律。试验结果表明,加速度峰值随水平距离的增加而逐渐衰减,同种扭力工况下,加速度峰值随频率增加呈现先减后增的趋势;随着激振频率增加,水平方向上加速度峰值由随扭力的增加而递增逐渐演变为递减的趋势;以衰减程度90%为标准,路基表面动力影响范围主要在1 m以内;动应力随垂直深度的增加逐渐衰减,影响范围主要位于2.9 m以内;随着水平及垂直距离的增加,自振频率与动剪切模量比逐渐增大,而阻尼比逐渐减小。根据路基动力响应特征及扫频试验结果,推测此段路基自振频率位于16 Hz左右。The dynamic stability of high-speed railway subgrade under long-term cyclic loading is critical,and the in-situ excitation tests have unique advantages for studying the dynamic characteristics of the subgrade.To study the dynamic response characteristics of the subgrade structure with the excitation frequency and torsion force variation,the in-situ excitation tests were carried out at the work site of Gu’an East Station of the Beijing—Xiong’an Intercity Railway.At the same time,a frequency sweep test was carried out to investigate the evolution of the natural frequency,the dynamic shear modulus ratio,and the damping ratio at different locations of the subgrade.The test results show that the peak ground acceleration(PGA)gradually decays with the increase of horizontal distance.Under the same torsion condition,the PGA exhibits a trend of first decreasing before increasing as the frequency increases.With the increase in excitation frequency,the PGA in the horizontal direction evolves from increasing to decreasing with the increase in torsion.The subgrade surface dynamic influence is mainly less than 1 m,with 90%of the attenuation degree as a criterion.The dynamic stress gradually decays with increasing vertical depth,with the main influence range being mainly located within 2.9 m.Furthermore,with the increase of horizontal and vertical distances,the natural frequency and dynamic shear modulus ratio gradually increase,while the damping ratio gradually decreases.According to the subgrade dynamic response characteristics and the frequency sweeping test results,it is estimated that the natural frequency of this subgrade section is located around 16 Hz.

关 键 词：高速铁路路基 原位激振试验 加速度 动应力 自振频率 

分 类 号：U213[交通运输工程—道路与铁道工程]