斜桩加固下覆倾斜基底软土桩-网复合地基离心模型试验

Centrifuge Model Test of Soft Soil for Pile-Net Composite Foundation with Overlying Sloping Base Reinforced by Inclined Piles

通过2组相似比为1:100的土工离心模型试验,研究斜桩对既有下覆倾斜基底软土桩-网复合地基的加固效果。试验结果表明,采用斜桩加固既有下覆倾斜基底软土桩-网复合地基,可有效减小路堤顶面的工后位移(竖向、水平),控制路堤顶面两侧沉降差的发展;同时,斜桩加固能有效抑制既有复合地基中斜坡桩、摩擦桩的桩顶水平和竖向位移,防止土工格栅的破坏及复合地基非对称"盆状"沉降的产生和发展;此外,斜桩加固可显著减小既有复合地基中的水平向推力,提高地基刚度及稳定性。研究表明,斜桩是加固既有下覆倾斜基底软土桩-网复合地基的有效措施。

Two geotechnical centrifuge model tests with a similar ratio of 1:100 were performed to investigate the reinforcement effect of inclined piles for the existing pilenet composite foundation on soft soil overlying sloping base.The test results show that due to the reinforcement of inclined piles,the post construction displacement(vertical and horizontal)on the top of the embankment is reduced effectively and the development of the settlement difference on both sides of the embankment top can also be controlled.Meanwhile,reinforced by the inclined piles,the horizontal and vertical displacement of the pile top of the slope pile and friction pile in the existing composite foundation can be restrained effectively,and the damage of the geogrid and the generation and development of the asymmetrical“basin”settlement of the composite foundation can be prevented.In addition,the horizontal thrust in the existing composite foundation can be reduced and the stiffness and stability of the foundation can be improved significantly by inclined pile reinforcement.The research shows that the inclined pile is an effective measure to reinforce the existing pile-net composite foundation on soft soil overlying sloping base.