【摘要】 支座是铁路桥梁的关键部件，在列车荷载和复杂环境条件作用下易发生各种形式的劣化。为实现损伤支座的快速定位与评估，该文提出一种基于车激动力响应的铁路简支梁桥支座刚度定量评估新方法。首先，推导了移动荷载列作用下空间弹性支承梁的动力响应理论解，据此提出基于列车激励下支座-梁位移比的损伤指标，揭示损伤指标与支座刚度间的数学关系，并建立基于损伤指标的支座刚度定量评估流程。然后，基于3D车桥动力相互作用仿真分析验证了理论解的准确性和评估方法的有效性，开展了参数分析和现场试验进一步验证了所提方法的鲁棒性与可行性。结果表明：随机列车荷载作用下提出的支座-梁位移比指标可有效定位损伤支座，且对轨道不平顺、横隔板损伤和噪声不敏感，抗干扰能力和鲁棒性强；通过建立的损伤指标与支座刚度间的数学关系可以进一步实现支座刚度的定量评估；采集5组过车数据即可获得较为准确的识别结果，从而在短时间内实现铁路桥梁支座状态的快速评估。更多还原

【Abstract】 Bearings are critical components of railway bridges and are susceptible to various forms of deterioration under the action of train loads and complex environmental conditions.To achieve rapid positioning and assessment of damaged bearings, this paper proposes a novel method for assessing the condition of railway simply supported bridge bearings based on the bearing-beam displacement ratio under train excitation.Firstly, the dynamic responses of spatial elastically supported beam subjected to moving loads was derived.Based on this, a damage index based on the bearing-beam displacement ratio under train excitation was proposed.The mathematical relationship between damage index and bearing stiffness was revealed, and a quantitative evaluation procedure for bearing stiffness based on the damage index was established.Subsequently, the accuracy of the theoretical solution and the effectiveness of the evaluation method were verified through 3D train-bridge dynamic interaction simulation analysis.Parameter analysis and field experiments were conducted to further validate the robustness and feasibility of the proposed method.The results show that the proposed bearing-beam displacement ratio index under random train load can effectively locate damaged bearings,and is insensitive to track irregularities,diaphragm damage,and noise,with strong anti-interference ability and robustness;The established mathematical relationship between the damage index and the bearing stiffness can effectively achieve quantitative assessment of the bearing stiffness;Collecting 5 sets of train passing data can obtain sufficiently accurate identification results,thereby achieving rapid assessment of the condition of railway bridge bearings in a short period of time.更多还原