Study on the Influence of Karst Size on the Vertical Bearing Capacity of Pile Foundation

Abstract Based on the actual project, this paper studies the vertical bearing characteristics of bridge pile foundation in karst area by Marc numerical simulation. The results show that the vertical ultimate bearing capacity of pile foundation has a negative correlation with the size of karst cave. With the increase of span, the bearing capacity of pile foundation and its sub- bearing capacity decrease. When the span of karst cave is 2m × 2m, the ratio of pile side resistance to pile end resistance is 3:1. When the cavern span is increased to 12m × 12m, the ratio of pile side resistance to pile end resistance is 9 : 1. Therefore, it is necessary to fully consider the influence of the size of the karst cave on the bearing characteristics of the pile foundation during the construction, and make corresponding engineering disposal measures according to the influence degree of different influencing factors, so as to improve the design and construction effect of the pile foundation.