Experimental and numerical studies on floor impact sound design of residential buildings

Abstract

In Korea, floor impact noise in apartment buildings frequently causes disputes between the residences, which rise as an important issue in the society. Main problem of the noise is heavy-weight floor impact sound which has low-frequency components below 200 Hz. It is induced by heavy-weight impact source such as childrens jumping or walking. According to Canada NRC research report (2010), heavy-weight floor impact sound is mainly influenced by structural system, floor plan type, thickness of slab, and boundary condition. It indicates that heavy-weight floor impact sound is a kind of structure-borne sound which is radiated by slab vibration. Thus, to fundamentally reduce floor impact sound, structural parameters related to slab vibration should be determined by designers first. Especially, numerical study for predicting floor impact vibration and sound is needed because experiments which investigate such parameters cost a lot of money and time in actual building design. And it should be considered at initial building design stage to prevent the plans which show poor floor impact sound insulation performance. Analytical solution for structure-borne sound including heavy-weight floor impact sound can be proposed with high accuracy if vibration analysis model predicts the actual behavior well. This study focused on proposal of total floor impact sound analysis process for designers in the practical field. The process includes numerical modeling, analysis, prediction and verification of floor impact sound. And it proposed several design values and detail process of numerical analysis for designers who have to perform the analysis with limited information. For this purpose, floor impact sound and vibration test in a multi-story residential building was firstly performed. And, to investigate applicability of the numerical analysis process on actual floor impact sound design, the test results were compared with corresponding results of finite element model. Finally parametric study on actual building design factors was performed to investigate the correlation with floor impact sound. The result showed that the proposed process predicts the floor impact sound within suitable error level range when compared with experimental deviation. Also, parametric study found that axial stiffness of resilient materials and section plan design parameters have high correlation with floor impact sound. Concrete material properties and floor area, aspect ratio showed relatively low correlation with floor impact sound.