Study on the Safety Evaluation Method of Life-Saving Passage in Building Ruins under the Action of Aftershock

It is essential to evaluate the safety of the life-saving passage in building ruins and to ensure the “double safety” of rescuers and trapped people during the earthquake rescue; however, there are few studies on the safety evaluation method of life-saving passage. In this paper, the vertical displacement of wood shoring is proposed as an evaluation indicator of the saving-life passage considering the characteristics of building ruins and the size of the living space of the trapped. Taking life-saving passage of the pancake-type building ruins as research object, the evaluation of the safety of the life-saving passage was investigated under the action of aftershock. The vertical bearing capacity test of wood shoring is performed in order to obtain the evaluation indicator of saving-life passage. The restart function of ANSYS/LS-DYNA program is used to re-edit the numerical model of the building ruins to construct the life-saving passage, then, the safety evaluation of life-saving passage of the pancake-type building ruins is investigated under the action of aftershock. The results show that the constructed life-saving passage passed the safety evaluation under the actions of different aftershocks. The possibility of the secondary collapse of the life-saving passage increases exponentially with the increase of rescue time within “72-hour gold rescue,” and the growth is slow after 72 hours when the magnitude of the main earthquake reaches above 7.4; the safety factor K should be increased appropriately if wood shoring is used to construct a life-saving passage when the main earthquake’s magnitude is greater than or equal to 7.5. The safety evaluation method of life-saving passage can provide effective reference for earthquake rescue.