人-桥竖向耦合振动计算方法

为了分析轻质人行桥的人-桥竖向耦合振动，建立了基于双脚支撑人体计算模型的人-桥耦合振动方程。根据行人在刚性地面行走时的步伐荷载计算结果与文献给出的步伐荷载时程曲线对比，验证了双脚支撑人体计算模型能较好模拟行人的脚步力特性。以一座跨度22.8m、第一阶竖弯自振频率7.23Hz的铝合金人行桥为例，运用Monte Carlo法模拟人群的步行参数，形成不同密度人群过桥的随机工况，并用直接积分法计算了考虑人群-桥竖向耦合振动的铝合金人行桥动力响应。计算结果表明，当人群密度较大时，考虑人桥耦合的人致振动卓越频率趋于分散，其振动响应明显小于不考虑耦合影响的计算结果。

Calculation method for vertical human-bridge dynamic interaction

In order to investigate the vertical human-bridge dynamic interaction of lightweight footbridges, a vertically coupling dynamic equitation based on bipedal pedestrian model is developed. A comparison between the simulated foot force on rigid ground and the curve from reference shows that the bipedal walking model provided in this paper can closely simulate the feature of ground reaction force. Rational ranges of the parameters of this bipedal model are discussed. A 22.8m-span aluminum alloy footbridge (with the 1st vertical bending frequency of 7.23Hz) is taken as the case to calculate the structural dynamic responses under vertical crowd-bridge interaction. Random crowd conditions of different densities are simulated with the generation of stochastic walking parameters by Monte-Carlo method, and the direct integral method is used for numerical analysis. The results indicate that, as the pedestrian density rises, the predominant frequencies of human-bridge interaction vibration tend to disperse, of which the responses are much less than the results that not consider the interaction.