## 7 Conclusions  
A comparative analysis of the vibration response and cumulative damage characteristics of a pipeline under different blasting methods using non-electric and electronic detonators was performed. The safety of the pipeline under tunnel blasting was evaluated, and a comprehensive vibration reduction technique was proposed. The key points are as follows. 1. Because the pipeline was located in the near range of the blasting source, it was mainly affected by the impact of the explosion of the closest holes. Through precise substitutability in-situ testing, it was found that the PPV generated by the current blasting plan would exceed the safety standard, reaching almost 30 cm/s;
2. Due to the spatial relationship between the pipeline and the tunnel, the vertical vibration response caused by the explosion was significantly greater than that in other directions. The maximum PPV in the vertical direction using non-electric and electronic detonators was 79.12 cm/s and 28.32 cm/s, respectively. The vibration  
Figure 19: Design of blast holes and damping holes in the upper bench. Figure 20: Field monitoring verifies the optimization results. (**a**) Monitoring point location. (**b**) Variation in the maximum PPV in the whole process of excavation. velocity was significantly reduced by 64.21% using the hole-by-hole initiation of the electronic detonators;
3. The location of the maximum PPV on the pipeline is at the bottom of the cross-section closest to the source of the explosion. Because of the large-diameter pipeline and its hollow characteristics, the PPV at the blasting side was much larger than that at the opposite side. The PPV decreased gradually as the distance along the axial extension of the pipeline from the blasting center increased, and the PPV of the electronic detonators decayed more slowly than that of the non-electric detonators. Because the maximum displacement of the pipeline was only 0.4 mm, the displacement standard was not suitable for evaluating the vibration safety of pipelines subjected to tunnel blasting;
4. The cumulative damage caused by the blasting of electronic detonators was less than that caused by non-electric detonators. After the nearest peripheral holes away from the pipeline detonated, the cumulative damage variable \(D\) and damage range increased rapidly, for non-electric and electronic detonator blasting increasing by 9.5 m and 4.7 m, respectively. The use of electronic detonator design can reduce the cumulative damage range by about 50.5%. The PPV, dynamic tensile strength, and cumulative damage variables were used to evaluate the safety of the pipelines. Division blasting, hole-by-hole initiation of electronic detonators, empty holes, and large pipe roofs were adopted to reduce the blasting vibration to meet safety requirements. The conclusions of this study were mainly applicable to pipelines made of reinforced concrete and similar materials. In future research, it will be necessary to further study the cumulative damage characteristics of cast iron and steel pipes caused by blasting and the corresponding safety evaluation methods. A more in-depth subject will be discussed, that is, the greatest disaster prevention and mitigation advantages that can be obtained by using scientific electronic detonator design under different failure criteria. However, there are some limitations in this study. Firstly, in the process of scheme transformation, the key parameters such as excavation footage, number of boreholes, and single-hole charge were basically unchanged, and just the position and time of boreholes were optimized. The main purpose was to set a separate delay time for each borehole by using an electronic detonator so as to realize the comparative analysis of the calculation results under the two schemes. In addition, the cumulative damage mentioned above is caused by the initiation of blast holes with different detonator series in the same excavation footage rather than by multiple forward excavations. X.G. : Methodology, Writing--original draft.