1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Zagreb 2020 earthquake severely damaged the historic centre of the City. Most of the damage occurred on historic masonry residential buildings of which many are situated in very close vicinity to the tram track. Vibrations generated by traffic can be harmful to buildings if they have been damaged by a previous earthquake. Vibrations could attribute to propagation of existing cracks. The effect of vibration depends on many factors, and one of the most important is the distance between the track and the building. The vibrations are highest at the source and their energy loss is due to transport through the soil to the recipients, so the vibrations at the recipients can be reduced by 2 to 15 dB. In this paper, the impact of tramway induced vibrations on earthquake damaged buildings in the city of Zagreb is described. In the first step of analysis, a track segmentation was performed based on the distance between the track and damaged buildings. Each segment was assigned a score based on the risk of vibration exposure. Vibrations were measured continuously on the entire length of tram track in earthquake affected area. Further analysis of vibrations transmitted to buildings is carried out in areas with high vibration levels.