Experimental evaluation of induced human walking vibrations on steel-concrete composite floors

Abstract

This work presents the experimental evaluation of the dynamic behavior of Steel and concrete composite floors, from a human comfort point of view, when submitted to human walking. The structural model investigated was a real composite floor system under construction, with a total area of approximately 1300 m2. A preliminary numerical model was developed in order to guide the ideal positioning of excitation and instrumentation to be adopted in the experimental “in situ” evaluation. Next, free vibration tests were carried out to obtain the modal parameters of the structure. More than 180 forced vibration tests with excitation caused by a person walking at different step frequencies and directions were performed to determine de maximum structure’s response. The results found were compared with human comfort criteria recommended by national and international standards and design guides. Subsequently, a people quantity influence analysis on the dynamic response of the floor was carried out, where it was noticed that the increase in the number of users walking on the floor also increased the peak acceleration value. This fact emphasizes the need to carry out experimental evaluations considering the variation of people quantity on floor activity in order to evaluate the real scenario of human vibrations induced in the structure under service.

Assessment of steel‐concrete composite floors dynamic response when subjected to people walking

“…Another important point concerns the multifunctionality that the business market has demanded from current engineering projects, based on the use of building floors for residential common use spaces, offices and gyms, which has contributed to these floors can be more susceptible to excessive vibrations associated to human activities, such as: walking, jumping, dancing, gymnastics, etc. [1,2]. This can be explained due to the fact that these human activities present excitation frequencies close to natural frequencies values of most structures, in the range of 4 Hz to 8 Hz [1][2][3][4][5][6].…”

“…The investigated structural model corresponds to a steel-concrete composite floor designed to receive a teaching hospital, located at the city of Belo Horizonte/MG, Brazil. The investigated floor presents a steelconcrete composite system of columns, beams, and steel deck slabs, with total area of 1300m² [1,2].…”

“…[1,2]. This can be explained due to the fact that these human activities present excitation frequencies close to natural frequencies values of most structures, in the range of 4 Hz to 8 Hz [1][2][3][4][5][6]. This way, in this research work the main objective is to evaluate the people-structure dynamic interaction effect on the structural behaviour of building floors, through the development of experimental tests and numerical modelling.…”

“…Aiming to evaluate the global dynamic behaviour of the structure, a numerical modal analysis was performed, and the results were calibrated based on the experimental response determined in the free vibration tests. Then, the experimental forced vibration tests were carried out on the composite floor, based on the use of different step frequencies, in addition to numerous trajectories adopted for the people walking on the slabs [1,2].…”

“…However, these floors are designed as light weight structures with low frequencies and low damping. These facts have generated slender building floors, with low natural frequencies and structural damping values, sensitive to human dynamic excitations, and consequently the serviceability and ultimate limit states has been changed [1,2].…”