软弱土地区PHC管桩复合地基加固参数研究

Research on Reinforcement Parameters of PHC Pile Composite Foundation in Soft Soil Area

摘要: 软弱土地区PHC管桩在不同设计参数下的工作性状和加固效果是实际工程关注的重要问题。结合实际工程项目，采用有限元数值模拟，研究地基沉降、管桩沉降、管桩轴力、桩土应力比等随上部荷载、桩长、桩间距等设计参数的变化关系，优化桩长桩间距设计。结果表明：PHC管桩加固填海区软土地基，可有效减小总沉降。桩长对软土地区PHC管桩复合地基变形、管桩受力、桩土应力比的影响显著。地基沉降随桩长增大而减小，但减小幅度放缓。同一工况下，管桩轴力均先增大后减小。在有效桩长范围内，增大桩长可以有效的减小地基变形，桩土应力比增长较快。在一定桩间距范围内，桩间距对工程沉降特性影响较大。随着桩间距增大，桩身最大轴力增长较快。

Abstract: The working behavior and reinforcement effect of PHC pile under different design parameters in soft soil area are important issues of practical engineering. Combined with the actual engineering project, the finite element numerical simulation is used to study the relationship between the foundation settlement, pipe pile settlement, pipe pile axial force, pile-soil stress ratio with the upper load, pile length, pile spacing and other design parameters, so as to optimize the design of pile length pile spacing. The results show that PHC pipe pile can effectively reduce the total settlement of soft soil foundation in reclamation area. The influence of pile length on PHC pipe pile composite foundation deformation, pile stress and pile-soil stress ratio is significant. The settlement of foundation decreases with the increase of pile length, but the decreasing range slows down Under the same working condition, the axial force of pipe pile increases first and then decreases. In the range of effective pile length, increasing the pile length can effectively reduce the foundation deformation, and the pile-soil stress ratio increases rapidly. In a certain range of pile spacing, the pile spacing has a great impact on the settlement characteristics of the project. With the increase of pile spacing, the maximum axial force increases rapidly.