Effects of ignition location on gas explosion dynamics and structural damage in a full-scale residential structure

Residential gas explosions pose severe threats to both structural integrity and human safety. Although gas leakage is a common trigger, the role of ignition location as a critical factor in governing the scale of disaster has not been systematically investigated. This study examined the effects of three ignition locations—bathroom, master bedroom, and dining room—on natural gas explosion dynamics and structural damage through full-scale experiments conducted in a 280.35 m3 residential compartment. Experimental results indicated that the ignition location dictates the entire disaster chain of gas explosion. Specifically, Bathroom ignition generated the highest external overpressure (90.95 kPa at 4 m). Master bedroom ignition induced the most complex combustion instability (characterized by wing-shaped and spoon-shaped flames). Dining room ignition resulted in the highest average peak temperature (1057 °C). The indoor flame evolution can be divided into three distinct stages: initial development, acceleration, and decay. Under the coupling effect of shock waves and combustion waves, four distinct glass fracture mechanisms were identified. External flame propagation behavior was significantly affected by the ignition location, showing notable differences in propagation distance, average speed, and merging patterns. This study provides a critical theoretical and experimental basis for risk assessment, disaster tracing, and protective design in residential gas explosion incidents.