倾斜悬臂支护桩受力变形特性模型试验

MODEL TEST ON BEARING AND DEFORMATION CHARACTERISTICS OF INCLINED CANTILEVER PILE IN DEEP EXCAVATION SUPPORT

在基坑支护工程中采用倾斜悬臂桩作为支护桩,可以有效减小桩顶位移以及桩身弯矩,改善桩身受力和变形特性。根据基坑支护倾斜悬臂桩模型试验,对5种不同工况进行模拟,对比分析倾斜角度、布桩方式、桩顶约束方式、桩位置四种因素对基坑支护倾斜悬臂桩受力变形特性的影响。试验结果表明:在一定范围内增大支护桩倾斜角度、增加桩顶约束都可以有效减小桩顶水平位移,改善桩身的变形和受力状态;斜直交替布桩方式较单纯全斜或全竖直布桩方式能更大地提高桩体抗倾覆能力,保持基坑稳定。

The inclined cantilever pile is used as the supporting structure in the foundation excavation engineering, which can effectively reduce the displacement of pile top and the bending moment of pile shaft, and improve the bearing and deformation characteristics of piles. Based on a model test of the inclined cantilever pile in deep excavation support, 5 different working conditions were simulated. The influences of four factors, such as tilt angle , pile pattern , pile top constraint and pile position , on the characteristics of bearing and deformation were compared and analyzed. The test results showed that increasing the angle of supporting pile or the constraint of pile top could effectively reduce the horizontal displacement of pile top, improve the deformation and stress state of the pile, and improve the anti overturning capacity of the pile. The alternating layout of veritical and inclined j)iles in deep excavation had better stability more than that of the simple layout of inclined or vertical piles.