The construction was postponed due to the COVID-19 and the rainy season. After resuming work and production, the project department insisted on epidemic prevention and control, safe and civilized production, construction progress and construction quality, overcame the impact of the COVID-19 epidemic, the geological disasters caused by the rain, poor geological conditions of the construction platform, and insufficient labor. Under the unfavorable factors, the project department worked together and hold special discussions to formulate construction plans adapted to local conditions, was aim at to optimize the blasting construction process, increase the investment and application of mechanical equipment. The Chinese employees of the project put themselves in the tunnel construction to make up for the shortage of personnel. The "two-shift" construction plan was implemented to improve the construction progress. Finally, the cable ventilation tunnel was completed under the condition of "zero accidents" in safety risks according to the plan.

ZSIM delivered its DW1002 rock drilling rig to the job site for blasting and bolting. The drilling rig is full hydraulic drive, the rock drilling speed can reach 0.8-2 meters per minute, and the engine is used to provide walking power. The machine has the characteristics of high lifting height, compact structure, low center of gravity, flexible maneuverability, and stable operation. DW1002 drilling rip helps the project department construction safety, reduces the work intensity of workers and improves the work efficiency.

Since the construction of the project, the project department has coordinated various resources, adhered to the concept of standardized and refined construction management, and achieved the primary goal of corporate benefits and zero safety risks. The project epidemic prevention and control has been institutionalized, standardized and normalized. Up to now, the project is orderly advancing the construction of the main traffic tunnel, tailwater slope, surge chamber and other areas of the main project of the underground powerhouse. The underground powerhouse will turn to key tasks such as excavation and support in the future.