地震作用下轨道-桥梁系统损伤与轨道不平顺的对应关系

针对地震作用下高速铁路轨道-桥梁系统损伤与轨道不平顺的对应关系不明确问题, 运用能量变分原理，推导了多层叠合结构层间变形协调关系表达式，将该表达式应用在高速铁路单元式和纵连式无砟轨道-桥梁系统中，按系统轨道形式与梁跨结点进行划段装配，提出了考虑路基与简支引桥影响的高速铁路基础结构变形与轨道不平顺的对应关系；采用现场实测、数值仿真模型与列车-轨道-连续梁桥-路基耦合动力学理论对对应关系进行了验证，并统计了地震作用下轨道-桥梁系统的损伤规律；基于提出的对应关系求得了考虑地震损伤的轨道不平顺样本，并采用数值仿真模型对其进行验证。研究结果表明:提出的对应关系与数值仿真模型求得的桥梁变形引起的轨道不平顺及现场实测值吻合较好，最大误差不超过5%，且轨道不平顺作用下车-桥动力学性能指标变化也基本一致，验证了本文提出的对应关系的正确性和有效性；地震作用下轨道-桥梁系统层间各部件的损伤较小，而支座的损伤较大，系统部件最大损伤位置在主梁梁缝处，但也仅约为支座损伤的1%；在不同水准地震作用下，采用提出的对应关系和数值仿真模型计算的地震损伤与轨道不平顺的对应曲线均吻合良好，说明提出的对应关系可用于计算与预测地震作用下高速铁路轨道-桥梁系统的轨道平顺性。 

Corresponding relationship between track-bridge system damage and track irregularity under seismic action

Aiming at the problem of the unclear corresponding relationship between track-bridge system damage and track irregularity on high-speed railway under seismic action, the energy variational principle was used to derive the expression of the deformation coordination relationship between the layers of multilayer composite structures. The expression was used in a high-speed railway unit and longitudinally connected ballastless track-bridge system, the sections were divided and assembled according to the track structures' forms and beam span joints, and the corresponding relationship between high-speed railway foundation structure deformation and track irregularity was proposed considering the influence of the subgrade and simply supported approach bridge. The field measurement, numerical simulation model and train-track continuous beam bridge-subgrade coupling dynamics theory were adopted to verify the corresponding relationship, and the damage law of the track-bridge system under seismic action was statistically analyzed. The track irregularity samples considering the earthquake damage obtained by the proposed corresponding relationship were verified by the numerical simulation model. Research results show that the corresponding relation is in good agreement with the track irregularity caused by the bridge deformation obtained by the numerical simulation model and the field measurement, and the maximum errors are not more than 5%. The dynamic performance indexes of the train-bridge under the effect of track irregularity are basically the same, which verifies the correctness and effectiveness of the proposed corresponding relationship. Under seismic action, the damage of the components between the layers of the track-bridge system is relatively small, while the damage of the bearings is relatively large. The maximum damage of the components is at the beam joints, however, it's only approximately 1% of the damage of bearings. Under the seismic actions with different fortification levels, the corresponding curves of earthquake damage and track irregularity are in good agreement, as calculated by the proposed corresponding relationship and the numerical simulation model, which indicates that the proposed corresponding relationship can be used to calculate and predict the track irregularity of high-speed railway track-bridge systems under seismic action. 1 tab, 10 figs, 33 refs.