大跨度人行桥、楼盖和长悬臂等结构的大量兴建，使得人致结构振动问题日益突出。人群荷载取值是人致结构振动分析、设计和振动控制的重要基础。尽管单人荷载的研究已基本成熟，针对人群荷载的基础性实验和理论研究仍相当薄弱，人群荷载的协同性因子是关联单人和人群荷载的关键。研究采用智能手机进行规模人群的同步荷载实验。首先对可用于人群荷载测试的智能手机软硬件系统进行选型研究，随后研究坐标转换、多机同步和人体力学模型识别三个关键技术，进而开展实际情形、规模人群的步行和跳跃荷载实验，建立包含密度、频率、外部引导等多要素的高质量人群荷载数据库，通过对实验数据的统计分析最终建立人群荷载协同性因子的概率模型以及用于工程设计的人群等效折减系数。项目研究充分发挥多学科交叉创新的优势，在实验方法以及建模思想上有创新。理论研究成果将为大跨工程结构人致振动问题的分析和计算提供荷载取值标准，同时为相关设计规范的修订提供科学依据。

Human-induced vibration serviceability problems are becoming more and more serious in practical engineering due to the rapid development of long-span footbridges, long-span floors and cantilever structures. Dynamic properties of crowd walking and jumping loads are crucial for proper structural design of such structures and are very important for design of vibration control device. Though load models for individual load are well established, experimental and theoretical investigations on crowd loads are very limited. The synchronization factor is the key link between individual load and crowd load. In view of this, this project aims to adopt smartphones for measuring crowd-induced walking and jumping load and to investigate the synchronization factor. First, small scale shaking table tests will be conducted on selected types of smartphones and applications (Apps) to study their vibration measurement accuracy. Then, three key techniques for crowd-loading measurements will be addressed, which are: coordination transform of smartphones’ records, synchronization of multiple smartphones and parameter identification of rigid-body model for human movement. After that, a series experiments will be conducted on crowd jumping and walking in order to establish a database consisting of high-quality data and covering different scenario. Probability distribution function of the synchronization factor will be analyzed and modeled based on the database. Finally a crowd-load reduction factor will be proposed which can be directly applied to engineering design. The research project is a cross-discipline one in which experimental techniques and analysis method in human movement science are adopted to resolve difficulties in structural engineering. The project aims to provide load model for human-induced vibration serviceability analysis and solid reference for revision of related design codes.