## 5 Blasting Vibration Reduction Effect Analysis Using Electronic Detonators
### Comparison of the Cumulative Damage to the Pipeline in the Two Blasting Schemes  
The cumulative damage to the pipeline in the numerical calculation was quantitatively evaluated using the damage variable \(D\). The cumulative damage caused by the two blasting methods performed five times simultaneously is shown in Figure 17. Regardless of the damage distribution range or degree of damage to the pipeline, the damage induced by the electronic detonator blasting scheme was much smaller than that of the non-electric detonator blasting scheme.  
Figure 16: Distributions of PTS and displacement on the cross-section of the pipeline using the two blasting schemes. (**a**) PTS; (**b**) displacement.  
Figure 15: The vibration response of the extracted elements at the closest profile of the pipeline. (**a**–**c**) are \(x\)-, \(y\)-and \(z\)-directions.  
The quantitative results of the cumulative damage range and degree of damage owing to the electronic and non-electric detonators are shown in Figure 18. Some valuable phenomena are worth discussing:  
1. Owing to the simultaneous initiation of cut holes using non-electric detonators, damage with a width of 1.5 m was generated on the pipeline. However, for cut-hole blasting with a small amount of charge using hole-by-hole initiation technology, the damage to the pipeline owing to blasting with electronic detonators is small;
2. With an increase in the number of blast hole ignitions, the range of influence of the seismic wave generated by blast hole blasting gradually increases; hence, the range of damage to the pipeline, induced by the non-electric and the electronic detonator blasting, gradually expands from the center of the nearest dangerous point to the sides. When the relief holes \(H_{2}\) are blasted, the damage range under non-electric and electronic detonator blasting increases by 3.0 m and 2.2 m, respectively. This is mainly because the relief holes above the cutting holes were much closer to the pipeline, and the number of blast holes detonated, and the number of explosives increased significantly, resulting in a greater increase in the cumulative damage to the pipeline;
3. Because some of the peripheral holes were close to the pipeline, and the influence range of the blasting seismic wave generated by peripheral hole blasting was larger than that of the other holes, the cumulative damage to the pipeline increased significantly with the initiation of peripheral holes. The cumulative damage range caused by the non-electric and electronic detonator blasting increased by 9.5 m and 4.7 m, respectively;
4. The increase in the damage variable \(D\) is consistent with the increase in the blasting damage range under the action of different blast hole blasting. When the relief holes above the cutting hole exploded, the damage variable \(D\) increased rapidly. The damage variable \(D\) of non-electric and electronic detonators increased by 0.18 and  
Figure 17: Evolution of cumulative damage in the original blasting scheme (**a**–**e**) and the improved blasting scheme (**a**–**e**) after comparing the five stages of blasting.  
0.12, respectively. In both explosion scenarios, the outermost peripheral holes are closest to the pipeline, and their explosive impacts significantly increase the damage variable \(D\). Therefore, the above results also prove that when the pipeline is in the close range of tunnel blasting, the influence of the explosive impact of relief and peripheral holes is larger than that of the cutting holes.