Dynamic behavior of an adjacent tunnel under blasting and collapse impact loads: a case study of high-rise building blasting demolition

Blasting demolition is widely used for removing high-rise buildings due to its safety and efficiency, but induced vibrations and collapse impacts can damage nearby structures. To study the dynamic behavior of an adjacent subway tunnel subjected to blasting and collapse impact loads during high-rise building blasting demolition, a 24-story building demolition project is taken as a research case. Vibrometers and strain gauges are installed in the tunnel to record its dynamic response. Additionally, an elaborate 3D numerical model is established to simulate the collapse process and clarify three distinct impact load characteristics. It is indicated that blasting vibration from the explosion and the high-velocity collapse of the building’s upper parts have negligible effects on the tunnel. However, the impact load generated on the basement, resulting from the failure of the primary incision and the building’s subsequent subsidence, exerts a critical influence on the tunnel. A parameter analysis reveals the decisive effect of the E r /E s ratio. It indicates that segment stress, unlike PPV, is the more reliable criterion for evaluating segment safety under such impacts.