An Experiment on a Real Building with Truss Roof to Validate Real-Time Early-Warning System for Fire-Induced Collapse

To reduce secondary casualties and support firefighters in making scientific decisions in rescue, a real-time early-warning system for fire-induced building collapse, with “real-time measurement, online data analysis, and real-time early warning” being its core, has been developed. To validate the effectiveness of the system, a fire-induced collapse test on a real building with a truss roof was conducted. The basic framework of the early-warning system is firstly reviewed. The test program is then introduced, including basic information about the test structure, loading scheme, measuring points, and equipment. The detailed test phenomena, and the thermal and structural responses are further described and analyzed. The test results revealed that the temperature distribution within the tested building is highly non-uniform, and the maximum temperature of the gas and steel components reached 900°C. The collapse mode of the truss was successfully identified by the early-warning algorithm based on the evolution laws of the displacements at the key joints of the truss, including prominent vertical joint displacements, buckling of the steel member of the truss, and bending failure of the top reinforced concrete chord of the truss. The test building collapsed after 4253 s after the ignition of the fire, and the developed early-warning system issued the remaining time to collapse in real time before the collapse of the test building. It is demonstrated that the predicted remaining time to collapse by the early-warning system was close to the real value.