Selection of pile foundations in karst areas

Aiming at the case that there have been no efficient and mature pile foundations and corresponding construction methods for karst areas with poor and complex geological conditions for long time, the state-of-the-art of pile foundations applied in karst areas is summarized, and the selection of piles is discussed. A number of recommendations are proposed based on the practical engineering experience from the design and installation of the pile foundations in Aidi Garden Phase II and Shenglong Garden Phase II in Longgang of Shenzhen. Particularly, Aidi Garden Phase II, constructed in deep karst area, exploits the aging effect of clay for supporting precast piles. It adopts the prestressed concrete pipes as friction piles, which do not touch the karst and thus eliminate its adverse impact. On the other hand, Shenglong Garden Phase II is constructed in shallow karst area, where the prestressed concrete pipes are employed as end-bearing pile groups to form piled raft, dispersing the risk of unfavorable geology.