建筑楼面活荷载的模态测试法

Floor live load survey by modal test

荷载取值是建筑结构可靠性设计的基础。楼面活荷载作为建筑荷载研究的重要内容,其现场实测及数据积累是统计建模的关键,然而入户称重和问卷调查的传统方式,存在效率低、样本少、可靠性低和时效性差等问题。该研究基于成熟的结构模态测试技术,提出由楼板模态质量获取楼面活荷载的新思路。首先通过理论证明结合数值试验,说明新方法的可行性,得到八种楼板边界条件下的模态质量到物理质量的转换关系,并给出实测时的具体操作步骤。通过模型试验和房屋实测对方法实用性进行检验,测试应用结果表明,所提方法的平均楼面活荷载测试精度满足荷载测试要求。配合简单的动力激振设备,利用此方法可实现楼面活荷载的便捷、高效检测。

The load value is the basis of structural reliability design.The floor live load is an important element in the building load research,and the accumulation of its field measurement data is critical in statistical modeling.However,the traditional way of"walk-in questionnaire survey plus weighing"for load is labor-intensive and low efficient.In the study,a new method is proposed to determine the floor live load from the modal mass of the floor based on the welldeveloped modal test technology.Firstly,the feasibility of the method is demonstrated by theoretical analysis and numerical simulation,and the conversion coefficient from modal parameters to physical parameters is given for eight types of boundary conditions of floor.The application procedure of the new method is then proposed.The practicality of the method is verified by conducting survey on a floor model and a real conference room,and the results show that the floor live load estimation using the proposed method is acceptable for live load surveys.By employing a portable dynamic excitation device in conjunction with the proposed method,the floor live loads can be obtained conveniently and efficiently.