The Research On The Effect Of Parameter Variations Of Pile End Soil And Pile Lateral Soil On Lateral Resistance Of The Pile

Pile foundation has the advantages of large bearing capacity, small settlement,can be used in complex geological conditions,therefore the pile is widely used in construction engineering.The character of bearing capacity of pile determines the effect that it can play,lateral resistance of pile as an important part of vertical bearing capacity of pile,there are many factors affecting its display,especially the change of parameters of pile side soil and the pile end soil has obvious influence on lateral resistance.Aiming at the shortcomings of research on side resistance of the pile,The factors influence on pile side resistance were studied,and get some valuable conclusions. The main work includes:1.The mechanism of pile side resistance are discussed, introducing the calculation method of bearing capacity of the single pile foundation in the theory and standard.At the same time, also expounds the calculation theory of group piles.2.Establishment of finite element model of pile and soil,by changing the parameters of pile side soil and the pile end soil,analysis of influence factors of pile side resistance.Mainly includes the pile diameter size, pile bottom sediment thickness,stiffness of pile end soil,internal friction angle and stiffness of pile side soil.Studies show that:the increase of pile diameter will decrease the pile lateral ultimate resistance,but reducing effect is not obvious;the presence of sediment had no significant effect to lateral resistance of the pile which away from the pile end,but decreased the resistance of pile side that near the pile end;lateral resistance of pile increases with the increase of elastic modulus at pile end soil,especially the lateral resistance of pile that near the pile end increased significantly;the increases friction angle and stiffness at soil of pile side significantly increases the ultimate side friction of pile.3.Numerical simulation on single pile in a project,the analysis results and the theoretical calculation result and the test results were compared,found that the maximum shear stress is in the vicinity of pile tip,the soil around the pile in the pile end had large deformation;compared with the sandy loess and clayey loess,the ultimate resistance maximum value exist in the sand,and in a small settlement will play a great side resistance;with the increase of load,each layer of soil of pile side resistance will increase,this shows that the pile side resistance has not displayed to the limit.4.Analysis characteristics of the bearing capacity and displacement to play of different pile modulus and pile length pile,the results show that :for the short pile, the pile compressionvolume is very small, can be neglected.When the pile length is more than 40 m, pile body compression accounted for the proportion of the displacement of pile top is high, especially the pile elastic modulus is small, at the same time we must consider the compression of pile contribute to the settlement of pile top. When the pile length is short, the pile body elastic modulus has no effect on the P-s curve.But the increasing of pile length,the smaller pile body elastic modulus is, the greater the compression of pile, lateral resistance of pile was the first to play out, but in the same load, the smaller the pile elastic modulus is,the greater the settlement of pile top.When the pile length is longer, the bearing capacity of the pile can be determined by the the strength of concrete pile.