João Guerreiro

This study presents the analysis of the falling trajectory of a seismic shelter placed on top of a masonry building when its collapse occurs. The test objective was to experimentally simulate the collapse of a vulnerable masonry building accommodating a shelter during an earthquake event. The test was conducted on the 3D seismic table at LNEC as part of the ”Structural Hyper-resisting Element for Life Threatening Earthquake Risk” project, known as the SHELTER project. This study aimed to develop seismic protection to increase survival rates in Unreinforced Masonry Buildings (URMs) in high-risk regions. Given the destructive character of the study, wireless instrumentation—specifically optical and wireless sensors—was preferentially employed. The investigation analysed the shelter behaviour during structural collapse to define requirements for enhancing its design.

Project SHELTER, Structural Hyper-resisting Element for Life-Threatening Earthquake Risk, aims at developing a strong and stiff functional unit to protect its occupants in case of severe earthquakes that lead to structural collapse. In case of collapse, these units will suffer impacts, particularly if they are installed in upper floors. To avoid severe injuries or death of occupants caused by collapse, safety chairs were designed, provided with shock-absorber systems and auxiliary retaining devices, to keep the occupants properly seated and safe. Three downfall scenarios were evaluated, consisting of vertical and tilted positions. A comprehensive numerical model to represent the human body was developed, mainly focused on chest behaviour and considering the anatomic limits of the vertebral spine. The mechanical ability of the safety chair to ensure the occupants’ safety was evaluated under these harsh conditions. Experimental downfall-and-impact tests will later be performed on shelter units, with crash-test dummies seated on the safety chairs for final validation.