Preservation of an Existing Original Building by Studying its Dynamic Properties

A 100 years old historical building, constructed with an original local concrete material and structural typology, is investigated. This building typology is commonly and exclusively found in Tripoli City located on the North Lebanon coast. The city, as well as Lebanon region, is a highly prone earthquake region. Aiming to mitigate the risk encountered by this original building typology, a preliminary study of the dynamic properties of its structural system is proposed. The approach consists of using the ambient noise method to determine the structural frequency, damping, and other characteristics. Moreover, the horizontal to vertical ratio method, HVNR is used to identify the natural frequencies of the building and of the nearby soil. Then possible resonance occurrence during likely earthquakes is investigated by comparing the obtained results. In parallel, the Finite Element Model of the structure is studied, and the results of the fundamental frequencies are obtained. Results and comparisons of experimental and numerical investigations are presented and discussed. This short-term structural health monitoring study is an essential preliminary and helpful tool to understand the performance of the studied building typology, in order to be able to propose strengthening and preservation solutions.