黄土地区长短桩基桩竖向承载特性研究

Study on Vertical Bearing Characteristics of Long and Short Pile Foundation in Loess Region

文中利用有限元模型,开展桩长比、长桩模量、端间土模量比以及加载量对桩基承载性能的影响研究。结果表明,桩长比与桩身沉降呈先快速下降、后缓慢下降关系,合理的桩长比为2.17;长桩模量与桩身沉降呈负相关关系,合理的长桩模量为1500 kPa;端间土模量比与桩身沉降呈负相关关系,端间土模量比为3时最为合理;不同桩长比、长桩模量、端间土模量比条件下,长桩桩身轴力与深度呈负相关关系;不同加载量条件下,长桩的桩身轴力与深度呈先缓慢增加、后缓慢降低的负相关关系,该现象随着加载量的增加而不断显著。随着桩长比、长桩模量、端间土模量比以及加载量的增加,长桩的桩身轴力不断增加。

In this paper,the finite element model is used to study the effects of pile length ratio,long pile modulus,soil modulus ratio between ends and loading amount on the bearing performance of pile foundation.The results show that the pile length ratio decreases rapidly first and then slowly,and the reasonable pile length ratio is 2.17.The modulus of long pile is negatively correlated with pile settlement,and the reasonable modulus of long pile is 1500 kPa.The soil modulus ratio between ends is negatively correlated with pile settlement,and the most reasonable one is when the soil modulus ratio between ends is 3.The axial force of long pile is negatively correlated with the depth under different pile length ratio,long pile modulus and soil modulus ratio between ends.For the axial force of long pile body under different loading conditions,the axial force and depth showed a negative correlation with a slow increase at first and then a slow decrease,and the phenomenon became more and more significant with the increase of loading load.The axial force of long piles increases with the increase of pile length ratio,pile modulus,soil modulus ratio between ends and loading amount.