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基于61人次2 204条实测的步行荷载曲线,提出了计算单人步行竖向荷载作用下大跨度楼盖加速度均方根响应的反应谱。以42 m跨矩形板为研究对象,首先得到每条实测步行荷载的反应谱,在此基础上建立设计反应谱的分段表达式:对应于步行1阶主频范围的第1平台段(1.5~2.5 Hz)、对应于步行2阶主频范围的第2平台段(3~5 Hz),以及对应于步行高阶频率的曲线下降段(5~10 Hz)。给出了2个平台段不同保证率的代表值计算方法和下降段的数学表达式。进一步研究了高阶振型、边界条件、计算跨度等因素对反应谱的影响,并给出了对应的修正方法。给出了建议反应谱的使用步骤,并应用于4个实际楼盖结构。对比分析表明,楼盖的实测响应接近或略大于反应谱75%保证率的计算结果,但均小于95%保证率下的计算结果,所建议的反映谱方法可用于计算单人步行荷载作用下大跨楼盖的加速度响应。
Based on the measured walking load curves of 2 204 persons for 61 persons, a response spectrum for calculating the root mean square acceleration of the long-span floor cover under the vertical load of a single person was proposed. Taking the 42 m-span rectangular plate as the research object, the response spectrum of each measured pedestrian load is obtained firstly. Based on this, a piecewise expression of the design response spectrum is established: the first platform segment corresponding to the first frequency range of walk (1.5 ~ 2.5 Hz), the second platform segment (3-5 Hz) corresponding to the 2nd frequency range of walking and the descending segment (5-10 Hz) corresponding to the higher frequency of walking. The method of calculating the representative value of different guaranteed rates of two platform segments and the mathematical expression of the descending segment are given. The effects of higher modes, boundary conditions, calculated span and so on on the response spectrum are further studied, and corresponding correction methods are given. The steps of using the proposed response spectrum are given and applied to four actual floor structures. The comparative analysis shows that the measured response of the floor is close to or slightly larger than the 75% guaranteed rate of the response spectrum, but both are less than the 95% guaranteed rate. The proposed reflectance spectrum method can be used to calculate the single-person walking load Acceleration response of large span floor cover.