Application And Study For Self-Balanced Bearing Test Of Bearing Capacity Of Cast-in-situ Pipe

The traditional static loading tester always rests on heap-weight platform types and anchored-reaction frame types.During testing.it takes long time,great effort and money to complete.Especially for the great tonnage pile,it is only tested by modeling test because it can not supply enough reaction force for the static loading test. We have to depend on experiences to design stake,so that there are many hidden trouble or so many piles cannot be exerted adequately.This is a waste in engineering project.Osterberg ,the professor of West- North university in America ,has put forward new ideas for static loading test.Firstly,putting a hydraulic pressure box on the bottom of the stake. Secodly,exerting pressure on the lumen of the box though a high-pressure oil pipe from the top of stake, after the-box top and box bottom are separated and the thrust generates up to down,then adjusting the shaft resistance and end resistance of the surrounding earth until the stake is damaged .Thirdly,adding the shaft resistance and end resistance to the compressive ultimate bearing resistance of single stake .It is characterized by the loding on the bottom of stake,using the shaft resistance and end resistance of stake as reaction ,so that it needn't supply the reaction and setting of reactio. It also needn't more time and effort to prepare the test .In china ,the researchers of college of water conservancy and hydropower engineering in Qing Hua university study this way.On the other hand ,the researchers of civil engineering of Southeast university and construction committee of Jiang su also study this way and spread the loading box to the engineering project..In this paper, the development of filling pipe and the ways of regular static loading test has been introduced.According to the actuai study state of the self-Balanced loading pile test,the principle,the equiment,the test ways and the buried technology of loading box for self-Balanced loading pile test has been summed up. The mechanism of the loading transmission of self -Balanced loading pile test has been analyzed in detail and compared with traditional test. The way of converse from the result of self-Balanced loading pile test to the result of traditional test has been introduced,and been improved to be reliability by using in the relative engineering project. Finally, the steps of this way has been shown according to the way successfully used on a engineering example.