Abstract:Under the background of rapid development of engineering construction, blasting technology is widely used in infrastructure projects, and its potential impact on the stability of adjacent key water conservancy facilities (such as reservoir dams) cannot be ignored. In this study, a lead-zinc mine adjacent to a dam in Tibet was taken as the background. Combined with field investigation and numerical simulation methods, the influence of excavation blasting in different underground sections on the stability of the dam was systematically explored. A fine three-dimensional numerical model of underground blasting and dam is established, and the influence of mining blasting on dam stability under three typical blasting conditions is simulated by using dynamic software ANSYS/LS-DYNA. The propagation characteristics of blasting vibration wave, shear stress distribution characteristics, particle vibration velocity (PPV) and acceleration of dam body are analyzed. The results show that with the propagation of blasting vibration wave, the stress of dam crest increases gradually, and the stress of rock mass at dam abutment and dam heel is significantly higher than that in other areas. The maximum shear stress of the unit at the top, abutment and heel of the dam is 073MPa. The PPV values of each measuring point in X , Y and Z directions were all less than 06cm/s. The comprehensive analysis shows that the blasting operations in the 3230m, 3300m and 3350m sections of the lead-zinc mine do not pose a significant threat to the stability of the adjacent dam body. The research results provide theoretical reference and technical support for the safe construction of underground engineering blasting, and provide new ideas and methods for the stability evaluation and risk management of reservoir dams.
