Abstract: An underground shell-pile continuous wall job practice, which utilizes a special drill for constructing a continuous wall underground, is initiated by sinking two coupled special drills connected together by male and female connectors fixed on the main trunks of them respectively. Then, the first special drill is withdrawn while simultaneously pouring concrete into it until the first shell pile is finished. The process of sinking special drills and withdrawing and pouring concrete to build shell piles is repeated until the whole continuous wall is finished. In this way, building an underground continuous wall is rapid, economic and effective. The special drill has a simple structure which provides for simultaneous insertion and draining of displaced soil, thereby reducing the sinking drag force. Thus, earthmoving normally required to build underground walls is reduced greatly.

Abstract: The present invention relates to an underground shell-pile continuous wall job practice, and meanwhile involves to its special drill for constructing said continuous wall underground. In the job practicing, by sinking tow coupled special drills connected with the male and female connectors fixed on the main trunks of them sequentially, then withdraw the first special drill as pouring concrete into it until finishing the first shell pile, next continue to repeat sinking special drill and withdrawing and pouring concrete to build shell pile until the whole continuous wall is finished. In this way, building an underground continuous wall is became rapid, economic and good effect. Said special drill has a simple structure, due to applying upside simultaneous draining soil, the sinking drag force becomes less, and meanwhile the earthmoving is reduced greatly.