In this article,the author concludes and analyzes study and application situations of tapered piles,and points out that the tapered pile is an advanced pile shape and is worth to be applied widely.

This thesis carries out some studies on the service behavior of the tapered pile and its mechanical properties in different soil layers, including the analyses of the theoretic bearing capacity and settlement, the field experiment results and analysis of economical effectiveness of the tapered pile.

Nowadays though the theory of tapered pile has been studied for almost 30 years,it is not universally used and aroused enough attention,which is due to the study on its bearing mechanism and characteristics have not deep understand as compared to the theory of uniform-section pile.

In order to probe into the feasibility of using wedge piles in Tianjin area,this paper studies the law of the variation of ultimate vertical bearing capacity,shaft resistance and tip resistance of a wedge pile by compressive loading on the top.

The pile strain of AM bulb cast-in-place pile is tested by high precision sliding micrometer,which can have high precision and reliable testing results.

Three dimensional failure envelope behavior of pedestal piles;

Research on the anti-pull forces of the pedestal pile in permafrost regions;

Behaviors of large diameter pile with straight shaft and pedestal pile

Analytical solution and test analysis of vertical tip bearing capacity of large diameter belled pile

Today,belled pile is used more and more widely in industry architecture,.

Four groups of vertical loading tests were performed on belled piles and equal-diameter piles at four sites to make comparative study.