On May 8th, the last thundering of gun ushered in a ray of sunshine into the tunnel, marking the surge shaft for Nam-Ngum-4 Project by China Heavy Machinery Co.,Ltd.(CHMC) had been joined up.

The whole length of the surge shaft for Nam-Ngum-4 project is 121 meter with the maximum diameter of 24 meter in excavation. Due to the complexity of rock, the carbonaceous shale and the mud stone formed the backbone of the surge shaft, posing new difficulty to construction for their susceptibility to water which can result in softening and swelling of the rock. During the construction period, the project team had achieved expansion of surge shaft by tiding over a series of difficulties including addressing difficult pore-forming of raise boring rig, excavation of pilot shaft, processing of side-wall rift and COVID-19 fallout.

In order to ensure success of the surge shaft, the project team held targeted discussion over construction difficulties, by communicating and coordinating with the local government, the green channel was opened while various epidemic prevention measures having been put in place, ensuring the entry of personnel, resources and equipment in an orderly way and secure and quality operation of engineering construction.

Currently, as the epidemic is still spreading abroad, making it a grim reality for responding to the epidemic. The successful joining up of Nam-Ngum-4 hydropower surge shaft greatly inspired the confidence of the project workers, laying a solid foundation for the completion of the project in time.