Abstract

This paper describes the methodology and the results of an in service assessment of a three-story glulam timber building. The entire structure is made of radiate pine glulam timber. After construction works for an elevator pit, excessive vibrations and slab deflections were reported. In order to evaluate necessity of countermeasures, a visual inspection, theoretical FEM analysis, ambient vibration measurement and 4-month inclination monitoring are conducted. For the monitoring two biaxial MEMS inclinometers are used. Initially a sample rate of 1 Hz is used, which is reduced to 0.2 Hz after the first 10 days of monitoring. Data is saved locally and in the cloud; warnings and alerts are generated automatically and send be email to the responsible engineers. As results, it is found that there are several critical design details that lead to a higher flexibility of the building; that the building has a relatively low stiffness and a low damping ratio; that dynamic structural deformations, incited by normal use, exceed the serviceability limits; and that the inclinations of the structure follows 4 natural cycles. It can be concluded that the works on the elevator pit did not initiate the vibration problems of the building. Based on the results, a retrofit project was designed for the structure.