Ultimate Bearing Characteristics and Envelope Analysis of the Composite Caisson Foundation with a Single Pile in Combined Loading Modes
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摘要: 运用数值分析法或试验手段建立不同加载模式下的地基承载力包络线是评价地基稳定性的重要途径。根据工程地质条件,采用有限元法建立吸力桶-地层的三维大型数值模型,进行桶型基础在水平荷载、竖向荷载、弯矩复合加载下的变形和承载力计算。结果表明,随着荷载的逐渐增大,复合桶型基础的位移初期呈线性增大,后期呈指数型增大、突变、失稳的变化规律,且适当的竖向荷载有利于提高复合桶型基础的水平和弯矩承载能力,过大的竖向荷载则会不利于基础的稳定。桶型基础的破坏包络线,对结构设计、基础稳定性的判定和整体安全的评价有重要作用。Abstract: It is an important way to evaluate the stability of foundation that establishs the envelope of bearing capacity for foundation in different loading modes by means of numerical analysis and tests. According to the engineering geological conditions, a three-dimensional large-scale numerical model of the suction-caisson and foundation by the finite element method was constructed. The deformation and bearing capacity of the caisson foundation under horizontal loads, vertical loads and bending moment were calculated. The results showed that with the gradual increase of loads, the displacement of the composite caisson foundation increased linearly at the initial stage, increased exponentially at the later stage, and became unstable at last. An appropriate vertical load was beneficial to improve the horizontal and flexural bearing capacity of the composite caisson foundation, while an excessively large vertical load was unfavorable to the stability of the foundation. The failure envelope of the caisson foundation played an important role in structural design, foundation stability judgment and overall safety evaluation.
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Key words:
- load mode /
- caisson foundation /
- bearing characteristics /
- envelope
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