Experimental Study on the Bearing Behaviour of Super-Long Post-Gouting Cast-in-Place Pile in Deep Soft Soil

Abstract

The post-grouting technology is widely employed in cast-in-place pile, but also a lack of awareness of the effect of post-grouting on super long cast-in-place pile in deep soft soil. To discover the mechanical mechanism of post-grouting cast-in-place pile in deep soft soil, O-cell pile testing before and after post grouting are carried out on two piles instrumented with steel-string transducer, and the frictional resistance and tip resistance are obtained. The following conclusion can be reached: 1) Side grouting and end-side association grouting can significantly increase the axial bearing capacity and the axial displacement decreases significantly at the same load. 2) The unit side resistance of pile is increased by using post-grouting and the effect on coarse-grained soil is better than that on fine-grained soil. 3) The load transfer law of overlength cast-in-place pile will not be changed by post-grouting, and the load-settlement curve will be slow descending. In order to increase the pile bearing capacity and reduce settlement simultaneously, side grouting can be the recommendation for super-long cast-in-place pile in deep soft soil.