INFLUENCE OF STIFFNESS OF BETWEEN-JOISTS BRACING ON VIBRATIONAL SERVICEABILITY OF WOOD FLOORS

摘要

Installing joist bracing consisting of components like solid blocking or cross-bridging elements can be an economical and effective means of mitigating vibration levels associated with unserviceable lightweight joisted wood floors. Effectiveness of different joist bracing methods depends on the location, geometric arrangement and stiffness of installed bracing elements. This paper presents an experimental investigation of how the equivalent flexural rigidities of joist bracings methods correlate with engineering parameters used in serviceability design of lightweight floors. Engineering parameters addressed are vertical deflection due to a central concentration static load, and low order natural vertical natural frequencies. Results show that the equivalent flexural rigidity of joist bracing correlates with static deflection of floors and natural frequencies. However, despite stiffening floors in the across-joists direction the extra mass of joist bracing elements can cause reduction in their fundamental natural frequencies. A method of determining the equivalent flexural rigidities of alternative joist bracing methods is demonstrated.