论文部分内容阅读
对长跨钢涵洞铁路桥进行实际动力响应研究。桥为土-钢组合结构,长11m。通过测量不同车速下桥的应变和位移,对桥进行试验,同时,对垂直道床振动以及制动力的影响也进行了测量。研究显示:车速对位移、推力和力矩的影响较大;所测的动态位移与推力比超出相应静态响应的20%,远大于桥设计规范所规定的值;力矩到1/4点时,动荷系数高达1·45,高于关键点的值。鉴于从强迫振动试验中测得了高的阻尼值,与普通桥相比这种桥的类型对共振并不敏感。
Study on Actual Dynamic Response of Long-span Steel Culvert Railway Bridge. Bridge for the soil - steel combination structure, length 11m. The bridge was tested by measuring the strain and displacement of the bridge under different vehicle speeds. At the same time, the effects on the vibration and braking force of the vertical track bed were also measured. The research shows that the influence of vehicle speed on displacement, thrust and moment is great. The measured dynamic displacement and thrust ratio exceed 20% of the corresponding static response, which is far greater than the values specified in the bridge design code. When the moment reaches 1/4 point, The load factor is as high as 1.45, above the critical point. In view of the high damping values measured from forced vibration tests, this type of bridge is less resonant-sensitive than normal bridges.