Pasternak地基中H(t)-V受荷桩水平响应有限杆单元法分析  

Analysis of Lateral Response of H(t)-V Loaded Pile in Pasternak Foundation by Finite Beam Element Method

作　　者：江杰[1,2,3] 艾永林 柴文成 龚健 欧孝夺 邵云怡[4] JIANG Jie;AI Yonglin;CHAI Wencheng;GONG Jian;OU Xiaoduo;SHAO Yunyi(School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University,Nanning 530004,China;Guangxi Ruiyu Construction Technology Co.,Ltd,Nanning 530299,China;China Shipbuilding NDRI Engineering Co.,Ltd,Shanghai 200063,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]广西大学特色金属材料与组合结构全寿命安全国家重点实验室,广西南宁530004 [3]广西瑞宇建筑科技有限公司,广西南宁530299 [4]中船第九设计研究院工程有限公司,上海200063

出　　处：《湖南大学学报（自然科学版）》2024年第3期99-110,共12页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(52068004)。

摘　　要：为探讨桩顶水平动荷载H(t)与竖向荷载V联合作用下桩基的水平响应,基于Pasternak地基和Euler梁理论,建立了桩-土相互作用水平振动分析模型,采用改进的有限杆单元方法求解考虑P-Δ效应、土体剪切效应影响的综合刚度矩阵方程,结合桩土连续边界条件得到桩身内力与位移解答.通过与已有解析解、有限元解和模型试验的结果比较,验证了计算方法的合理性.最后,对影响桩身内力与位移的主要因素进行分析.结果表明:1)传统Win⁃kler地基相较于Pasternak地基模型,忽略了地基土体的剪切效应,将夸大桩体结构的实际受力,使得计算得到的桩身水平位移和弯矩均大于Pasternak地基所得结果,且随着桩土弹模比Ep/Es的降低,两种地基模型计算的桩身最大水平位移和弯矩的差异性呈现出增强趋势;2)随着桩顶竖向荷载的增加,桩身水平位移和弯矩受P-Δ效应的影响显著.当桩顶竖向荷载特征参数λ由0增至2时,桩身最大水平位移和弯矩分别提高40.85%和78.57%;3)相较无限长桩(L>20d_(p)),有限长桩的水平位移和弯矩的动力响应受桩身长径比L/d_(p)影响更大;桩身最大水平位移和弯矩随着水平简谐荷载幅值H_(0)的增加而增大,随着无量纲频率a_(0)的增大而减小.To investigate the lateral response of a pile under the combined action of lateral harmonic load H(t)and vertical load V at the top of the pile,based on the Pasternak foundation and Euler beam theory,a lateral vibration analysis model of pile-soil interaction is established.The improved finite beam element method is used to solve the comprehensive stiffness matrix equation considering the P-Δeffect and soil shear effect,and the corresponding analytical solution is obtained by combining the pile-soil continuous boundary conditions.The rationality of the proposed method is verified by comparing its predictions with the results of existing analytical solutions,finite element solutions,and model tests.Finally,the main factors affecting the internal forces and deformations of the pile are analyzed.The results show that:1)Compared with the Pasternak foundation model,the traditional Winkler foundation ignores the shear effect of the foundation soil,which exaggerates the actual force of the pile so that the calculated lateral displacement and bending moment of the pile are larger than the results obtained by the Pasternak foundation.Additionally,as the pile-soil elastic modulus ratio(Ep/Es)decreases,the difference in maximum lateral displacement and bending moment between the two foundation models becomes increasingly pronounced;2)As the vertical load on the pile head increases,the lateral displacement and bending moment of the pile are significantly affected by the P-Δeffect.When the characteristic parameterλof the vertical load on the pile head increases from 0 to 2,the maximum lateral displacement and bending moment of the pile increase by 40.85%and 78.57%,respectively;3)Compared with the infinite pile(L>20d_(p)),the dynamic response of the lateral displacement and bending moment of the finite pile is more affected by the slenderness ratio L/d_(p);The maximum lateral displacement and bending moment of the pile increase with the increase of the amplitude of the horizontal harmonic load H_(0),and decrease with the in

关 键 词：水平动荷载 轴向荷载 有限单元法 PASTERNAK地基 动力响应 

分 类 号：TU473.1[建筑科学—结构工程]