Study On Bearing Characteristic Of Auger Bored Cast-with-pressure Concrete Pile And Its Engineering Application

Auger Bored Cast-with-pressure Concrete Pile is a new style of pile which is used in recent years.This pile is with various sections though sending concrete with high pressure pump and the squeeze on the pile of soil compaction effect. Compared with other ordinary cast-in-situ piles, this pile can reduce the construction cost effectively,shorten construction time,so,this new style of pile is provided with high social and economic benefit.But research works on Auger Bored Cast-with-pressure Concrete Pile is not systematic,at the same time,the bearing mechanism and bearing behavior of the pile under compressing loads are not clear. Therefore,to assure the safety and economic,it is urgent to further study and bearing property of Auger Bored Cast-with-pressure Concrete Pile,in which we can combine the theory with pratice.The main work and conclusions of the paper are listed as follows:(1)It analyzed the load transmission theory and its influencing factors theoretically. Based on field test results, it analyzed bearing mechanism of Auger Bored Cast-with-pressure Concrete Pile, and studied deeply.(2) ANSYS was applied to analyze the stress and displacement field.The Y-displacement of ground caused by the pile decreases with the depth increasing.When the load reached ultimate state,the soils around the screws reached shear failure state. It is further understanding of bearing mechanism.(3)Field static loading test was carried out, the measured data agree with finite element analysis data well.(4) Proposed the idea of using gray system theory to predict single pile ultimate bearing capacity of Auger Bored Cast-with-pressure Concre-te Pile, and comparing with measured results from engineering examples. It is proved that the prediction curve agree with measured curve,and the prediction results are more safely.The results show that it can use this method to predict single pile ultimate bearing capacity of Auger Bored Cast-with-pressure Concrete Pile,and the allowable bearing capacity is credible, also the accuracy is full compliance with the engineering practice, it can be applied to engineering practice.(5) According to the analysis of research results in this paper, this kind of pile is different from ordinary concrete pile, as compared with it significantly increased the carrying capacity of the pile, it provided with high technical and economic benefits.