The study of damage expansion process of the surrounding rock mass under blasting is of great significance to the blast resistance design of a chamber.In order to explore the damage propagation law of the surrounding rock mass around a chamber under the action of different blasting sources,a numerical calculation model including top explosion,vault side explosion,side wall explosion,bottom side explosion and bottom explosion was established by using the finite element simulation software ANSYS/LS-DYNA.The RHT model was used to analyze the damage propagation process of the chamber surrounding rock mass at different positions.On this basis,10 vibration velocity monitoring points were set equidistantly from the blast source to the chamber boundary in the model,and the vibration velocity attenuation law from the blast source center to the chamber boundary was studied.The results show the damage point first appears at the shortest distance from the blast source,and is then formed subsequently.The damage zone expands gradually along the boundary of the chamber and finally forms the damage zone.Compared with the decay law of the blasting vibration velocity,the blasting vibration wave is fully reflected in the surrounding rock mass,which makes the blasting vibration velocity appear an amplification effect.At the same time,the damage evolution from the blast source to the surrounding rock mass corresponds to the change law of the peak vibration velocity,which can be used to determine if damage happens.