Study on the dynamic evolution of safety performance durin g the renovation cycle of historical blocks

Historical blocks are the key to urban context, carrying cultural heritage and style. Changes in spatial form during the renovation of lifen buildings are prone to hidden dangers. The study took Wuhan Sandeli as the object, constructed a fire model with PyroSim software, analyzed the changes in smoke visibility, temperature field and CO concentration threshold of three types of rooms; calculated the evacuation time of personnel in different scenarios with pathfinder software, and analyzed the evolution of building safety performance by combining available and required safe evacuation time. The results show that the closure of space during the renovation makes the day and night evacuation exceed the safety standard, and the reduction of exits, delayed emergency response and the superposition of the characteristics of the aging population affect evacuation safety. The study proposed protection measures to provide a basis for safety optimization in the transition period of historical building renovation.