嵌岩扩底桩抗拔承载特性的数值模拟研究

以四川广元输电线路的嵌岩扩底抗拔桩现场试验为分析对象，运用岩土有限元软件PLAXIS 3D模拟现场试验，数值分析与现场试验实测的Q-s曲线吻合良好，验证了参数选取的正确性和计算模型的合理性。在此基础上，通过数值计算，深入研究了扩大头的尺寸、桩径、嵌岩深度、覆盖层厚度以及坡度对嵌岩扩底桩极限抗拔承载力的影响。结果表明:Q-s曲线呈陡变型，出现了明显的拐点；扩大头直径、桩径相比嵌岩深度对提高抗拔桩的刚度系数有显著效果。

Numerical Simulation Research of Uplift Bearing Characteristics of Rock-socketed Pedestal Pile

Based on the field test of rock-socketed pedestal uplift pile in Guangyuan electric transmission line in Sichuan as the research object, geotechnical finite element software PLAXIS 3D was used to simulate field tests, and numerical analysis and Q-s curve measured by field tests coincide well, the results show that the parameters for selection are correct and the model is reasonable. On such basis, the influence of the enlarged head size, pile diameter, rock-socketed depth, cover layer thickness and gradient on the ultimate uplift bearing capacity of the rock-socketed pedestal pile was deeply studied by numerical calculation. The results show that the curve shape of Q-s is steep and there is an obvious inflection point; the diameter of the enlarged head and the diameter of the pile have a significant effect on the increase of stiffness coefficient of the uplift pile.