The paper has a study on length influence to large diameter friction piles by 5 groups contrastive load test in 5 test sites and obtained some useful conclusions.

Research on axial bearing behavior of large diameter piles;

Using the ABAQUS software,the static load testing results of two large diameter piles have been simulated by the three-dimensional finite element numerical method.

This paper introduced the principle of sliding micrometer in test of large diameter pile body, and compared it with traditional method and indicated that t his kind of method has the merit of accurate test result and can appraise the quality of pile body.

The large diameter piles (LDPs) not only have stronger bearing capacity with less deformation, but also have some other advantages: flexible in application, simple in computation, convenient for construction, and economical in materials consumption, etc.

Construction difficulties and its counter measures of big diameter piles in bridges;

Study on the relationship between the bearing capacity and settlement of large-diameter pile;

Based on analyzing the characteristic of soil resistance surrounding large-diameter pile,the hyperbola model of soil resistance surrounding pile and the parameters of the model by the experiment were given.

Owing to the fact that the bearing capacity of large diameter pile is very strong, to obtain the integrated relationship of load settlement of large-diameter pile by site test is very difficult,Whether to the load conditions or to the test techniques.