KARST CAVE DISPOSING TECHNOLOGY FOR PILE FOUNDATION CONSTRUCTION,ILLUSTRATED WITHYONGHE BRIDGE IN JI'AN

Karst cave disposing is crucial for pile foundation construction in karst area. This paper systematically summarizes the influence of Karst cave to pile foundation, the principle of Karst cave disposing and the basis on selection of disposal methods. As an example, the pile foundation construction of the Yonghe Bridge in Ji'an City, is taken to show how to choose the optimal strategy in practical projects. The geologic conditions, surrounding environments, and project issues(safety, quality, construction schedule and costs) are taken into account. The scheme in practice shows good results in preventing large ground subsidence, ensuring the stability of hole wall, and improving the quality of the piles. The study provides a reference for the similar projects of Karst cave treatment in the future.