Abstract: Cast-in-place reinforced concrete pile installation in the karst terrain by using conventional construction means and methods is usually problematic. Construction related hazards include no slurry return, caving of borehole. In addition to the difficulties in the pile installations, these hazards might induce the sinkholes collapses, over-turning of the construction equipment and even casualties of the construction crews. A new construction method, which is called all casing and full circulation method, that is specially designed for the cast-in-place reinforced concrete pile installation in the karst terrain, can minimize the construction related hazards. This paper presents a case history of using the new construction technique in the karst terrain.

Key words: full casing and full circulations, karst sinkhole, pile installations