A novel energy dissipation blasting technique based on water coupling is proposed to explore new methods for rapid excavation of spillway protection layers in hydropower stations under relatively intact hard rock conditions. This method specifically addresses the excavation requirements of the Nam Kong 1 Hydropower Station spillway in Laos. By increasing borehole pressure, the technique generates stronger stress, which is advantageous for excavating hard rock formations. Simulation analysis using LS-DYNA software demonstrates that coupling water-charged explosives with a blocked borehole bottom amplifies the peak load on the borehole walls and extends the explosive load duration, thereby improving the fragmentation of harder rock at the borehole bottom. Results indicate that the combination of bottom-hole blockage and water-coupled charges increases lateral damage depth and prolongs load application time, thus achieving more effective excavation and formation in relatively intact hard rock. Comprehensive evaluations based on numerical simulations and field test parameters confirm that this approach significantly improves the quality of excavation and formation of the first-stage stilling basin floor in practical engineering applications.

The DBDP Hydropower Station, the largest hydropower station under construction in Pakistan, faces challenges related to blasting vibration affecting freshly poured concrete of the proposed intake tower of the diversion tunnel. Finite element calculation parameters were adjusted based on on-site blasting vibration monitoring data to address this issue. A numerical simulation method was utilized to analyze the blasting vibration response of the water intake tower under various blasting conditions and to identify factors influencing peak particle velocity(PPV). The study proposes measures to control blasting vibration. The results indicated that the maximum charge per delay, the delay time between blast holes, the advancing direction, and the detonation position significantly impact the intake tower′s vibration. It is recommended that the maximum charge per delay and the delay time between blast holes be controlled to mitigate vibration on the fresh concrete. Additionally, adopting a backward blasting advancing direction and hole-bottom initiation is advisable.