Research On The Influence Of Blasting Vibration On The Stability Of Adjacent Slope

In the past several years,with the wide application of blasting in excavation,the slope disturbance caused by blasting vibration has become a major safety problem in slope engineering construction.Therefore,it is necessary to study the stability of slope under blasting load.This article takes a nuclear power plant infrastructure construction blasting excavation project as an example.The theory,measured data and numerical simulation are taken into account,the stability of the slope during blasting excavation is analyzed,specific research and conclusions are as follows:（1）Analyze the propagation mechanism,type,related parameters of blasting vibration wave and the current methods of predicting the intensity of blasting vibration in detail,then analyze the frequency of blasting vibration wave to gain a deeper understanding of the relevant characteristics of blasting vibration wave,and finally analyze the blasting vibration wave.The impact of vibration on slope stability is analyzed.（2）The blasting test is carried out by determining the blasting design plan,and the monitored peak velocity and vibration frequency are respectively combined with the Sadowski formula and the blasting vibration frequency calculation formula for regression analysis to obtain the slope measuring point vibration velocity and vibration frequency change formula,and preliminary Determine the vibration velocity threshold of the slope mass point.（3）The ANSYS software combined with the finite element strength reduction method was used to analyze the slope establishment model before the blasting construction,and the displacement and stress distribution of the slope were obtained;in addition,the safety factor of the site slope stability was determined to be 1.83 according to the criterion of slope failure.Provide reference theory for on-site blasting construction.（4）The ANSYS/LS-DYNA software to establish a slope model,analyze the displacement,velocity,and effective stress changes of the slope under the action of blasting vibration load.In a single blasting,the slope is in a stable state,the vibration displacement of the slope top and the effective stress response of the slope toe are the most prominent,and there is a vibration velocity amplification effect at the top of the slope;in the case of multiple blasting,when the blasting vibration load reaches a certain value,the slope Displacement will appear non-convergence phenomenon,the stress of the slope foot exceeds the ultimate stress strength of the slope rock,and the slope will be unstable and damaged.Combined with the standards of the blasting safety regulations,the maximum safe vibration velocity thresholds at the top and toe of the slope are obtained as V = 10 cm/s and V = 21 cm/s,respectively.（5）Obtained through on-site blasting construction monitoring data,according to the "speed-frequency" two-factor analysis,the peak velocity at each monitoring point of the slope is less than the vibration velocity safety threshold determined above,there is no damage to the slope rock mass;The vibration frequency change is mainly manifested in the increase in the position of the top of the slope.The comparison between the actual measurement and the simulation results proves the accuracy of the previous numerical simulation analysis.