随机人群行走荷载下混凝土楼板振动分析

Analysis of concrete slab vibration induced by random crowd load

为了对人群行走荷载下的混凝土楼板结构振动进行更可靠预测及评估,首先,基于机器学习,提出能准确预测混凝土楼板结构动力特性的智能方法,该方法预测得到的混凝土弹性模量比规范公式计算所得精度更高.其次,通过对经典的人群疏散社会力模型进行修正,提出随机人群行走模型;该模型能同时考虑人群行走参数的个体内变异性和个体间变异性.然后,将随机人群行走参数与单人步行荷载模型相结合,得到随机人群行走荷载模型;该模型因考虑了人群行走参数的变异性而能考虑所致荷载激励频率成分的随机性.最后,实现了随机人群行走荷载下混凝土楼板振动智能分析方法.将该方法用于分析混凝土楼板在人群行走下所致振动,考虑了不同人群密度、楼板平面尺寸、厚度、混凝土密度、抗压强度、边界条件及阻尼比等对楼板动力响应的影响,并根据相关规范和指南对楼板振动舒适度进行了评价.

This paper aims to reliably predict and assess the concrete slab vibration induced by crowd load.A machine learning-based intelligent method is proposed to accurately predict dynamic characteristics of the concrete slab.The method has superior accuracy in predicting the elastic modulus of concrete compared with the formulas in codes.Furthermore,the classical social force model for the crowd evacuation is modified to be able to simulate the walking behavior for pedestrians under daily life circumstances,which can simultaneously consider inter-and intra-subject variabilities of walking parameters and thus provide inputs for the walking force model.The two parts are integrated as a random crowd load model.The intelligent analysis method of the concrete slab vibration induced by the random crowd load is finally developed.The proposed method is applied to analyze the crowd induced vibration of a typical concrete slab.Meanwhile,parametric studies are performed to investigate how the structural responses are affected by the crowd density,the slab's plan size,thickness,concrete density,concrete compressive strength,boundary condition and damping ratio.Vibration serviceability of the slab is also assessed according to the norms and guidelines.