Rock Fill Grouting Hollow Concrete Pile Foundation Construction Process

The bore-hole cast-in-situ pile foundation has been born widely used in bridge Engineering. Since the foundation engineering is demanded to be very strict and the quality of pile foundation is difficult to ensure, new technique of pile foundation construction has to be developed to overcome shortage of traditional bored pile foundation engineering. Combined with the key scientific research project of Henan Provincial Department of Communications in 1998: The research and application of the stone-fill grouted concrete in the bridge foundation engineering, construction technics and design theory of stone-fill grouted concrete construction in hollow pile was deeply studied in this paper.With the retrospection of the developing course of the bored pile foundation and combining with my practical experience, the paper expatiates upon the design principle of percent of fit of the stone-fill grouted concrete and the main factors of the influence strength target, and the final pile technique introduction of the hollow pile of the stone-fill grouted concrete and the precast prestressed concrete; Baesd on the theory of slurry hydraulics, empirical calculation formulas of the radis and height of diffuse slurry are deduced in this paper; It analyzes the test pile materials of the hollow pile foundation, such as Luoyang Yi River Bridge and Dangwang Jian River Bridge; The new technique of the hollow pile, which provides the generalization and application with base materials, expounds its feasibilities, adaptabilities and economy. By analyzing the several finished bridge projects, if the hollow pile foundation is adopted, we can economize subaqueous concrete consumption more than 40 per cents; If the grouted new technique of pile surroundings and pile toe is adopted, we can increase the load capacity 30 per cents than that of the replacement pile, and economize 20 per cents of the cost. It will show great and obvious economic and social benefits.