The Study On The Prestressed Concrete Piles Of Longitudinal Cracks

As China's booming construction industry, in high-rise buildings, heavy plant, bridges, ports, offshore oil platforms and nuclear power plants and other projects in the extensive use of pile foundation, pile foundation has become China's most important construction projects of a foundation pattern , pile foundation construction cost typically accounts for more than a quarter of the total cost of civil works, the quality of the pile foundation have a decisive effect on the construction of quality , so the quality of testing on the pile on the significant is very important.Prestressed concrete piles (referred to as PC pile) have a wide range of applications with its high strength concrete, resistance to bending, resistance to cracking and corrosion-resistant ability, penetration force, construction of high efficiency and good quality. But in the pile driving process, particularly in the use of hammer-pile construction process, some reinforced concrete piles had longitudinal cracks, which will seriously affect the stability of the pile, if not detected to correct the pile , there will be produce an immeasurable loss.This thesis analysis of the prestressed concrete piles in the pile longitudinal cracks generated in the process of the formation mechanism, Namely, in an instant hitting, the piles internally generated horizontal tensile stress greater than the pile itself, the horizontal tensile strength; and use the large-scale finite element software ANSYS to simulate the prestressed concrete piles when the piling were transient hit .According to the force, proposed of the easiest location of the vertical cracks ,①When the pile tip into the soft ground most likely to happen when the general location of the vertical cracks in the upper part of the pile;②when the pile tip into a hard bearing stratum, the most likely location of the vertical cracks in the general area at the pile tip; and explained the wave theory in the use of the pile testing detection, based on the old detection methods ,proposed new detection methods—Next to the hole transmission method, According to the new inspection method, in the actual project, can detect the location of the longitudinal cracks in pile foundation. For example:a,select the appropriate piling machinery;b,replacement of pile mat timely;c,the reinforcement of the pile and so on.According to this formation mechanism , This thesis proposed some measures to control the longitudinal cracks occurred. Through this thesis provided some basis to foundate for future testing and development.