Comparative Study On Blasting Effects Of Rock Slopes Based On LS-DYNA Numerical Simulation

With the continuous development and improvement of blasting technology and blasting theory,blasting has become an important engineering tool for many national economic sectors including mining engineering,civil engineering,water conservancy projects,etc.,and its application has become more and more extensive,which has promoted the development of China’s economy.However,the variability of the blasting construction environment and the imperfect blasting theory make us need to use a variety of means to strengthen the research on blasting engineering.Among them,the numerical simulation method has the characteristics of low cost and high efficiency,and it has become an effective means to study engineering blasting.In this paper,nonlinear dynamic finite element analysis software LS-DYNA is used to study the blasting process of rock slope,based on the comparison with the blasting test of a nuclear power plant to verify the correctness of the numerical simulation,the numerical simulation of rock blasting under different charging structures,detonation methods and blasting construction conditions is carried out to investigate the blasting effect under different blasting processes.A reasonable blasting scheme is given by comparing and analyzing the calculation results of specific engineering cases.In the case of enclosure blasting with given geological environment and blasting parameters,the pressure peak above the blasthole increased by 87.4%compared with the positive detonation,the damage zone reached the surface,and the length of the largest radial damage zone increased by 50%,the blasting effect is better;In the case of bench blasting,when the uncoupling coefficient is 1.75 compared to the case where the uncoupling coefficient is 1.00 and 2.50,it can make full use of the explosive energy to form a large explosion rupture zone,and avoid excessive vibration effects on surrounding buildings,so it is a reasonable uncoupled charge selection;In the case of Xiluodu slope blasting excavation,based on previous studies on the damage distribution,further analysis showed that the damage distance of smooth blasting in the direction of the vertical final slope surface exceeded about 50%of pre-split blasting;The maximum vibration velocity peak(156cm/s)of smooth blasting is also significantly higher than that of pre-crack blasting(98cm/s),For the water slope,not only the smooth surface should be obtained,but also the disturbance to the retained rock mass should be avoided as much as possible.The calculation results of the integrated smooth blasting and pre-splitting blasting are better.Therefore,it is more suitable for the blasting construction of the Xiluodu slope.At the same time,it is recommended to use the blasting excavation method with a delay of 15ms according to the calculation results.