摘要
冲刷是导致深水桩基失效的重要原因。由于水流具有方向性,冲刷坑常呈非对称形状,这可能会对桩基产生更不利影响。鉴于此,基于非对称冲刷坑模型求出任意深度处的极限土抗力,得到修正的p-y曲线。引入余弦函数表征径向土压力分布,考虑冲刷效应修正的被动侧桩侧摩阻力、“P-Δ”效应及冲刷引起的自由段变化,构建桩身挠曲微分方程,提出非对称冲刷条件下组合受荷桩基水平承载力计算方法。通过与室内试验结果、有限元模拟结果对比,验证该文方法的合理性。研究结果表明:采用传统对称冲刷模型与非对称冲刷模型计算的桩基水平承载力差异显著,且该差异随着桩两侧冲刷坑深度、宽度增大以及坡度减小而愈发明显;冲刷效应会放大“P-Δ”效应,增大非对称冲刷和传统对称冲刷计算理论之间的差异;被动侧冲刷深度Sd2增大使得弯矩最大值位置不断下移,并与冲刷坑底部的距离减小。
Scour is an important cause for the failure of deep water pile foundations.Due to the directional nature of water flow,scour pits tend to be asymmetrical in shape,which may exert a more detrimental effect on the pile foundations.The ultimate soil resistance at any depth was found based on the asymmetric scour pit model to obtain the modified p-y curve.Furthermore,cosine function was introduced to characterize radial earth pressure distribution.Given the pile lateral frictional resistance modified by the scour effect,the"P-Δ"effect and the change of free section caused by scour are considered,and the pile deflection differential equation was constructed,while the horizontal bearing capacity calculation method of combined loaded pile foundation under asymmetric scour conditions was proposed.The method was verified by comparing the indoor test results and the finite element simulation results.According to the results,there was a significant difference between the horizontal bearing of pile foundation calculated by traditional symmetric scour model and asymmetric scour model.Moreover,the difference became increasingly obvious as the depth and width of scour pit on both sides of the pile increased and the slope decreased.The scour effect amplified the"P-Δ"effect and increased the difference between asymmetric scour and traditional symmetric scour calculation theories.Besides,the increase of scour depth Sd2 on the passive side made the position of the maximum bending moment continuously move down and the distance from the bottom of the scour pit decreased.
作者
江杰
余云东
欧孝夺
柴文成
罗豪豪
JIANG Jie;YU Yun-dong;OU Xiao-duo;CHAI Wen-cheng;LUO Hao-hao(College of Civil Engineering and Architecture,Guangxi University,Nanning,Guangxi 530004,China;Guangxi Ruiyu Construction Technology Co.,Ltd.,Nanning,Guangxi 530225,China;Guangxi Guiguan Electric Power Co.,Ltd.,Nanning,Guangxi 530025,China)
出处
《工程力学》
北大核心
2025年第3期191-202,共12页
Engineering Mechanics
基金
国家自然科学基金项目(52468045,52068004)
南宁市创新创业领军人才“邕江计划”资助项目(2023016)。
