Influence Of Blasting Vibration On Stability Of Tailings Dam

The blasting vibration produced by underground blasting may reduce the stability of the adjacent tailings dam,and make the dam break the danger of dam break.If the dam breaks down,it will pose a serious threat to the living environment and property of the downstream residents.In this paper,the liquefaction of tailings under different amplitudes was studied by indoor test.Secondly,the physical and mechanical parameters and the terrain data of tailings dam was established,and the stability of tailings reservoir was analyzed under the condition of water level change.Finally,through the field blasting vibration test,the attenuation equation of wave velocity was determined.The influence of blasting vibration on tailings reservoir slope stability was analyzed,and a three-dimensional model was established to further analyze liquefaction and deformation of tailings reservoir under blasting vibration.The main conclusions are as follows:(1)The amplitude of 0.05~0.2mm in pore water pressure,reached the effective confining pressure,the specimen without the occurrence of liquefaction.Under the maximum amplitude was 0.4mm,the pore pressure was more than 0.8,and the partial stress tended to 0,and the initial liquefaction of the sample appears.(2)The daily explosive dosage was no more than 30 kg,and the maximum velocity amplitude of the pillar and roof of the 527 goaf of the left bank of the tailings reservoir was 0.102cm/s and 0.229cm/s respectively.The tailings dam safety can be considered according to the safety allowable standard of blasting vibration,and the safety of the tailings reservoir was considered as the safety factor of the 512 goaf.(3)Without considering the seepage model,under the condition of non rainy season safety coefficient of tailings dam was 1.328,the potential landslide shear outlet in first steps,the safety coefficient under the condition of the rainy season was 1.287,meet the requirements of anti sliding stability of tailings dam slope,dam safety.(4)Under the vibration load,the maximum vibration velocity of the nearest monitoring point of the distance source was 0.280cm/s,which was greater than the estimated blasting vibration speeded 0.229cm/s.The pore water pressure and the effective stressed curve of each monitoring point are basically straight,and there was no significant fluctuation.The pore pressure ratio was much lower than that of 0.8~1.0,so the tail ore library will not be sentenced to liquefaction phenomenon.