cross-laminated timber floor
Project Highlights
We conducted a set of vibration tests on a residential building floor with cross-laminated timber (CLT) panels to understand the effect of non-structural components on the dynamic response of the floor. The floor construction included a single 7-ply CLT panel in a three-span configuration, with a maximum span of 27.75 ft, finished with an acoustical mat and a 1.5-inch-thick gypcrete topping.
vibration criteria
The floor structure was designed to meet the vibration criteria for residences (16,000 to 32,000 mips – micro-inches per second) per U.S. Mass Timber Floor Vibration Design Guide.
Solution Strategy
Vibration tests were conducted as the building construction is nearing its completion at two separate times. For Test 1, all CLT panels and the studs of the partition walls were installed. For Test 2, gypcrete topping and the acoustical mat on the CLT panels, as well as the gypsum boards of the partition walls, were all installed.
The following tests were conducted:
- Heel drop tests
- Walking tests
- Instrumented impact hammer tests
results
Analysis of the vibration data showed that adding non-structural components increased the floor’s fundamental frequency by about 20% and reduced walking-induced vibrations by roughly 47% on average. The stiffness of completed partition walls also altered the fundamental mode shape, an effect not observed when only wall studs were present. Finite element models of the tested structures were also developed by our team to identify parameters that would more accurately capture the effect of non-structural components.
Before and after Test