Influence of Karst Caves at Pile Side on the Bearing Capacity of Super-Long Pile Foundation

Abstract

The differences in development and situation of karst caves lead to two kinds of karst caves, and the karst cave may be on the pile side or at the pile bottom, which has a different influence on the bearing capacity of pile foundation. The paper presents a numerical analysis of the influence of karst caves at pile side on the bearing capacity of super-long pile foundation in karst areas. According to the size of pile foundation of a real bridge project, this paper modelized karst caves and investigated the karst cave from the effect of length, height, and thickness of roof on horizontal and vertical bearing capacity of pile foundation. The main conclusions can be drawn as: when the horizontal displacement at the top of pile foundation is greater than 0.05 m, the horizontal load is correlated positively with the length of karst cave; when the vertical displacement is greater than 0.07 m, the vertical load is correlated negatively with the thickness of the roof of karst cave. However, the height of karst cave has little effect on the bearing capacity; also the existence of karst cave has little influence on the dynamic response of pile foundation. The results of this study can be important with reference to the design and construction of pile foundations in karst areas.