Abstract: The seismic wave will be induced in the blasting demolition projects of buildings and structures when the collapsed reinforced concrete structure impacts the ground at high speed. The prediction of vibration velocity of seismic waves is essential to analyze the influence of demolition projects on the environment and design control measures. Based on the plastic deformation characteristics of soil under the intense impact， momentum conservation theory，and dimensional analysis method，we established a collapse vibration prediction model with a wide contact surface. Some actual cases verified the validity of the calculation model. It shows that the calculation accuracy of the model can meet the needs of engineering design，and it is easy to use.

Key words: demolition blasting, collapse impact, vibration velocity, mathematical model