Innovative Application of Needle-beam Full-circular Formwork Jumbos in Construction of Lining of Sub-sea Water-diversion Tunnel

Needle-beam full-circular formwork jumbos are used in the construction of the secondary lining of the intake tunnel of Taishan Nuclear Power Plant,so as to realize once-for-all and rapid construction of the full-circular concrete lining of the sub-sea water-diversion tunnel.In this paper,the method and procedure of the construction of the secondary lining are analyzed,the main structure and technical parameters of the formwork jumbos are presented,and the key construction technologies are described.Furthermore,three innovative points of the application of the formwork jumbos,including the construction arrangement and design inside and outside of the tunnel in the case of 3 formwork jumbos,the continuous construction of the lining by means of 3 formwork jumbos and the cautions for the continuous construction of the lining by 3 formwork jumbos,are summarized.