The Study Of Linear Charge Blasting Seismic Effect Based On ANSYS/Ls-dyna Simulation

In the process of blasting engineer construction, the linear charge is often chosen as the source structure in the blasting engineering, but in the blasting process it can cause ground vibration, which will endanger the safety of the building or the people around, so, the study of blasting seismic effect has a long-term significance. Based on the blasting of linear charge in rock medium as object of the research, by the program of finite element numerical simulation calculation which is named ANSYS/ls-dyna people analysis the effect of blasting vibration.First of all, from the aspects of the rock blasting mechanism and the formation of seismic wave, the theory of blasting vibration is discussed, and the four theories of rock damage are told. From the aspects of the concept of linear charge, the method and theory of calculation,blasting stress and its attenuation equation, the study of calculation theory concerning the linear charge blasting is told.Secondly, the calculation method of finite element software named ANSYS/ls-dyna by which the model of rock blasting was constructed and solving steps is intntroduced. through the study and analysis of the stress nephogram at the different time in the blasting process, the characteristics of stress distribution under the condition of the center initiation are summed up;Through the study of velocity time history diagram, the change rule and difference of the radial velocity and axial velocity are pointed; By the fitting method of function, the peak value of radial and axial particle vibration velocity to curve are fitted, it is concluded that the function relation between the peak value of radial and axial vibration velocity of each particle and the distance from the particle to the explosive source; By comparing with the vibration velocity which was measured in the blasting, it is proved that the fitting formula and the method of the numerical simulation are correct and reasonable or not.Again, that the blasting process of the linear charge under the condition of terrain which has slope is simulated. through the study of velocity time history of the particle in the stairs up and down surface, it is concluded that slope blasting has amplification effect, the speed variation regulation of the particle in up and down the steps is provided in the paper.Under thecondition of the different charge structure, it brings the blasting seismic effect. The dynamic response of a simply supported beam was analyzed under explosion shock loading.Finally, the safety assessment method of bridge is proposed under the action of blasting seismic.Combining the feature of blasting seismic effect and control principle of blasting seismic effect, several shock absorption measures about linear charge are put forward.