冲刷作用下斜坡桩基竖向极限承载力评价方法
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摘要
由于不能考虑土体冲刷对桩周土体初始应力的影响及随着冲刷深度的增加桩周土体压缩回弹效应的增强,简单地按高承台形式来考虑水流冲刷作用对桩基承载性状的影响是不够准确的.文中建立了考虑冲刷深度比率的冲刷作用下斜坡桩基竖向承载力评价模型.设计了10组数值模拟实验,采用FLAC3D弹塑性分析软件,分析了冲刷作用对桩端阻力与桩侧摩阻力的影响机理.采用非线性回归分析,建立了冲刷作用的影响系数函数;使用基于麦考特法的通用全局优化算法进行迭代计算,确定影响系数函数的参数,得到冲刷作用下斜坡桩基竖向极限承载力评价方法.
Since the influence of soil erosion on the initial stress of soil around the pile cannot be considered, and the compression rebound effect of soil around the pile increases with the increase of erosion depth, it is not accurate to simply consider the influence of water erosion on the bearing behavior of pile foundation according to the form of high pile cap. In this paper, an evaluation model of vertical bearing capacity of slope pile foundation under scouring action considering scouring depth ratio was established. Ten sets of numerical simulation experiments were designed and FLAC3 D elastoplastic analysis software was used to analyze the mechanism of scour effect on pile tip resistance and pile side friction resistance. Using nonlinear regression analysis, the influence coefficient function of scouring effect was established. The general global optimization algorithm based on mccourt method was used for iterative calculation to determine the parameters of influence coefficient function, and then an evaluation method of vertical ultimate bearing capacity of slope pile foundation under scouring action was obtained.
Since the influence of soil erosion on the initial stress of soil around the pile cannot be considered, and the compression rebound effect of soil around the pile increases with the increase of erosion depth, it is not accurate to simply consider the influence of water erosion on the bearing behavior of pile foundation according to the form of high pile cap. In this paper, an evaluation model of vertical bearing capacity of slope pile foundation under scouring action considering scouring depth ratio was established. Ten sets of numerical simulation experiments were designed and FLAC3 D elastoplastic analysis software was used to analyze the mechanism of scour effect on pile tip resistance and pile side friction resistance. Using nonlinear regression analysis, the influence coefficient function of scouring effect was established. The general global optimization algorithm based on mccourt method was used for iterative calculation to determine the parameters of influence coefficient function, and then an evaluation method of vertical ultimate bearing capacity of slope pile foundation under scouring action was obtained.
引文
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[3] CATHERINE B, MARCEL S, DIRK R Z, et al. Rill development and soil erosion: a laboratory study of slope and rainfall intensity[J]. Earth Surface Processes & Landforms, 2010,35(12):1456-1467.
[4] 胡丹,李芬,张开银.冲刷作用下水平承载单桩静动力特性试验研究[J].武汉理工大学学报(交通科学与工程版),2015,39(6):1255-1258.
[5] 陈鹏,李文华,范涛,等.土体冲刷对桥梁桩基影响的三维差分模拟计算分析[J].山东科技大学学报:自然科学版,2007,26(4):23-26.
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[7] 汤虎.冲刷对海洋平台桩基水平承载性能影响的研究[D].武汉:武汉理工大学,2012.
[8] 王楠,徐永臣,宋玉鹏,等.冲刷作用下桩基承载能力分析[J].海洋地质前沿,2013,29(9):54-58.
[9] 李君兰,蔡强国,孙莉英,等.降雨强度、坡度及坡长对细沟侵蚀的交互效应分析[J].中国水土保持科学,2011,9(6):8-13.
[10] 孙书伟,林杭,任连伟.FLAC3D在岩土工程中的应用[J].2011(2):43-47.
[11] 中华人民共和国建设部.建筑地基基础设计规范:GB50007-2002[S].大连:辽宁科学技术出版社,2002.
[12] 中交公路规划设计院有限公司公路桥涵地基与基础设计规范:JTGD63—2007[S].北京:人民交通出版社,2007.
[2] 张光辉,刘宝元,李平康.槽式人工模拟降雨机的工作原理与特性[J].水土保持通报,2007,27(6):56-60.
[3] CATHERINE B, MARCEL S, DIRK R Z, et al. Rill development and soil erosion: a laboratory study of slope and rainfall intensity[J]. Earth Surface Processes & Landforms, 2010,35(12):1456-1467.
[4] 胡丹,李芬,张开银.冲刷作用下水平承载单桩静动力特性试验研究[J].武汉理工大学学报(交通科学与工程版),2015,39(6):1255-1258.
[5] 陈鹏,李文华,范涛,等.土体冲刷对桥梁桩基影响的三维差分模拟计算分析[J].山东科技大学学报:自然科学版,2007,26(4):23-26.
[6] 闫澍旺,高江林,王成华.水流冲刷对桩基承载性状影响的数值模拟[J].岩土力学,2009,30(5):1458-1464.
[7] 汤虎.冲刷对海洋平台桩基水平承载性能影响的研究[D].武汉:武汉理工大学,2012.
[8] 王楠,徐永臣,宋玉鹏,等.冲刷作用下桩基承载能力分析[J].海洋地质前沿,2013,29(9):54-58.
[9] 李君兰,蔡强国,孙莉英,等.降雨强度、坡度及坡长对细沟侵蚀的交互效应分析[J].中国水土保持科学,2011,9(6):8-13.
[10] 孙书伟,林杭,任连伟.FLAC3D在岩土工程中的应用[J].2011(2):43-47.
[11] 中华人民共和国建设部.建筑地基基础设计规范:GB50007-2002[S].大连:辽宁科学技术出版社,2002.
[12] 中交公路规划设计院有限公司公路桥涵地基与基础设计规范:JTGD63—2007[S].北京:人民交通出版社,2007.