Ground surface vibration response law of different axial charge structures in tunnel hydraulic blasting
To investigate the influences of charge structures on the blast-induced ground vibration characteristics in hydraulic blast-ing,several onsite experiments were conducted in the context of Xinbin tunnel at the Shenyang to Jilin Expressway.Based on the onsite experiments,the peak particle velocity(PPV)and dominant frequency(DF)were analyzed under different kinds of charge structures,which includes the normal charge structure,the water bags located in the top of blasthole,the water bags located in the blasthole collar and the water bags located in the both ends of blasthole.In addition,the distribution laws of ground vibration under different charge structures were further studied using numerical simulation.The research results indicated that,compared with the normal charge structures,less explosive energy is converted into vibration energy in hydraulic blasting,resulting in smaller PPVs and higher DFs.Within 5 m of the cross section along the tunnel excavation face,the PPVs of blasting vibration under the normal charge structure exceed the vibration safety criteria,which is adverse for the safety control of ground structures.The converted vi-bration energy is relatively smaller along the direction of water bags in blasthole,but on the opposite direction of the blastholes more explosive energy is converted into vibration energy.In tunnel blasting excavation,the charge structure of the water bags locat-ed in the both ends of blasthole was recommended to promote the uniform distribution of vibration energy and minimize the distur-bance to the surrounding structures.
万方数据
维普
