Simulation And Analysis Of The Bearing Characteristics Of Supper Long Single Pile Foundation

With the expansion of the city, faced with limited land, the land utilization rate increasing, which requires to increase this rate by increasing the height and depth of the expansion of a building. So the settlement and deformation of foundation is more and more strict, and the application of super long pile is more and more widely. Besides research on super long pile has accelerated the pace. Taiyuan is currently in development stages of super high-rise, but use less of super long pile. Related engineering experience, Taiyuan is building a high-rise building (such as drill design elevation of333meter Ferris). So the paper needs the soil information in conjunction with the relevant calculation theory of super long pile, and uses calculation software of geotechnical areas FLAC3D4.0. The paper simulates and analysis useful theoretical and practical references in the region of super long single pile foundation.When using the FLAC3D4.0software for simulation, the paper selects soil related works and Moore Coulomb model, and uses space axial symmetry of the one-fourth model, taking into account the main factors influencing on a reasonable simplification of the model. In addition to the paper encrypts the pile tip and pile tip soil unit. Doing these can improve the model’s speed and precision. Through appropriate analyses to draw the following conclusions:(1) When the diameter increases, bearing capacity of single pile grows, and axial force at the same depth as a percentage of the total load increases correspondingly, and the amplitude decreases. Bearing capacity of pile foundation of pile diameter can be increased, when the pile diameter exceeds a certain value. And the base bearing capacity of pile diameter increase moderately;(2) When the length of pile increases, bearing capacity of single pile grows, and the settlement of pile tip reduces accordingly. And length of pile impacts on compression of pile less. With the increase in length, axial force of pile passed down along the amplitude decreases. Increased length can increase the ultimate bearing capacity of pile. But pile length exceeds a certain value, increasing of pile ultimate bearing capacity is not obvious;(3) When the increase in modulus ratio of pile and soil, pile ultimate bearing capacity also increase. And the increase accordingly reduces the settlement of pile top, but has little effect on settlement of pile tip. Above a certain load, modulus on side resistance of pile-soil has little effect;(4) When the cohesion increases, pile and pile-side settlement is essentially the same, and pile side resistance base is not affected. So changing cohesion has little effect on bearing capacity of single pile;(5) When the angle of internal friction increases, bearing capacity of piles increases modestly. Angle of internal friction has little effected on compression of pile and axial force distribution of pile. When exceeding a certain load and under certain loads, pile side resistance increases with increasing angle of internal friction.