Dashuikeng Reservoir Expansion Blasting Project in Huaniao Island Successfully Completed

The Dashuikeng Reservoir expansion mountain blasting project was located in a mountain valley in Lighthouse Village on the western side of Huaniao Island, Shengsi County, Zhoushan City. The island is far from the mainland, and it took approximately eight hours by boat from Zhoushan to reach the construction site, making transportation extremely inconvenient. Frequent disruptions caused by strong winds increased the difficulty of transporting machinery and explosives, resulting in repeated delays to the blasting schedule. Through the efforts of the project team and coordination among the public security authorities, township government, stationed military units, and other departments, the blasting operation was successfully carried out at 15:23 on November 6, 2016, achieving favorable results.

The construction conditions of this project were highly complex, placing extremely high requirements on the blasting operation. The mountain slopes on both sides of the reservoir were very steep, and transportation roads could not reach the bottom of the reservoir. To reduce the amount of muck handling and lower construction transportation costs, the reservoir expansion project could not adopt the conventional method of multiple blasting excavations by benches. After careful study, a one-time blasting formation method was adopted. By improving drilling accuracy, all blast holes were arranged according to the terrain on both sides of the reservoir, with drilling completed to the designed depth in a single operation and the excavation formed through one blasting operation.

The surrounding environment of the project was also highly complex. Beneath the reservoir were power grid facilities and residential areas. The nearest transformer was only 54 m away; the closest masonry residential house was 77 m away; the newly constructed temporary reservoir and dry-laid stone retaining wall were only 35 m away; and a military tunnel was located approximately 100 m behind the reservoir slope.

To protect the surrounding structures and facilities, the blasting area was divided into five zones, with delayed initiation adopted between each zone. Within each zone, the maximum charge per delay was strictly controlled according to the distance between the blasting area and protected structures. A sequential initiation network using in-hole decked charges or single-hole single-delay initiation was adopted to limit blasting vibration velocity and ensure the safety of surrounding structures.

After more than one month of design, construction preparation, and field operations by the project team, the blasting was successfully completed. The blasting results met the design requirements, and all surrounding protected structures remained intact. The project received unanimous recognition and praise from government authorities, the project owner, stationed military units, and local residents.