The Comparison Of Two Methods Of Vertically Compressive Static Loading Test For Pile Foundation In Dalian Area

Vertical compressive static loading test of the foundation piles is now recognized as the most direct and reliable test method to detect the vertical compressive bearing capacity of foundation piles. At the same time, for vertical compressive static load test of foundation piles, according to the maintaining time of load in every load the convergence of foundation piles settlement under the load in all levels, the loading test is divided into Slow Load Maintain Method and Quick Load Maintain Method.The provisions which are based on the 《Technical code for testing of building foundation piles》(JGJ106-2003), such as4.3.5:we should adopt Slow Load Maintain Method to provide the basis for the design. And such as4.3.7:Slow Load Maintain Method should be taken to inspect the piles after the construction. Quick Load Maintain Method can be used when there is a mature experience in some region. To sum up, the Slow Load Maintain Method is the preferred method for the Vertical Compressive Static Loading Test. But in the practical work, Quick Load Maintain Method is widely used because that its testing cycle is significantly shorter than that of Slow Load Maintain Method.In this article, to analysys and study the property of the socketed pile, through the comparisons of the Slow Load Maintain method and Quick Load Maintain Method, and the analysis of static load data and the Q-S curves, S-lg Q curves, S-ig T curves, we will find out that, under each level load, the differences of settlement caused by Slow and Quick Load Maintain Methods, and the differences of ultimate bearing capacity obtained from the slow and quick method (2times of the static load carrying characteristic value in the tests). We also put ADINA which is the Numerical analysis software into use to compare with the practical experiments, considering the contact effect between the pile and soil, carry on the single factor analysis method, and give the effect of the pile diameter, elastic modulus of pile, modulus of soil, Poisson ratio of soil on the loading-settlement curve of pile.Based on the all above, we can provide effective and reliable comparative basis of slow and quick methods for the static compression test of foundation piles in Dalian area.