【作者】 王平；

【导师】 徐东强；

【作者基本信息】 河北工业大学 ， 结构工程， 2006， 硕士

【摘要】 桩基础是一种历史悠久,又广泛采用的基础形式,历次世界大地震中,均出现了各类桩基础的严重破坏现象。由于破坏的隐蔽性,使得破坏桩基的修复极为困难而且耗资巨大,因此对地震作用下的桩-土-承台动力相互作用进行数值模拟研究具有重要的学术意义和较强的工程实用价值。本文运用ANSYS软件对群桩进行有限元模拟,分析了群桩基础在竖向静载作用下的工作性状。对群桩模型同时施加竖向静载及水平动载,进行地震作用下桩-土-承台动力相互作用的有限元分析,并通过施加不同的地震波对群桩的地震反应进行了对比,得出以下结论:1.承台的存在限制了群桩上部桩、土的相对位移,影响了桩身荷载的传递性状,从而使基桩上部的侧阻力发挥不充分,即对侧阻力起“削弱作用”。侧阻力不像单桩那样从桩顶开始发挥,而是从桩的中部开始发挥。2.通过土体沉降图可以分析得到,在群桩效应作用下,桩间的土体沉降量明显比外侧的大些。3.在地震波作用下桩头与承台的连接处、桩身的上部应力较大,在地震作用下容易首先破坏,在设计和施工当中应引起足够的重视,加强桩头与承台的连接强度。4.通过对模型输入不同的地震波,可以看出在相同加速度时,EI Centro波比天津波能产生更大的地震反应。更多还原

【Abstract】 Pile foundation has been used to consolidate soft ground for a long history,and it is also one popular method to be used to improve foundation today.Many pile foundations are damaged seriously during the past large earthquakes.Large amount of cost will be paid to remedy the defect of pile foundation undergoing earthquakes,so it is a significant value for both academic and concrete project to study the subject of numerical modeling of Pile-Soil-Cap dynamic interaction under seismic loading.In this article,ANSYS FEM program is used to study the performance of pile groups under the vertical load.The vertical static load and dynamic load are imposed on the group piles model,analyzed the dynamic interaction of pile-soil-cap.Through imposing different seismic waves to compare the seismic response of group piles,obtained some conclusions:1.The cap restrained the relative displacement of pile and soil,influenced the pile load transfer characteristics so that the friction force is given play to insufficiently at the top of pile.Compared to the single pile,the development of friction force did not appear at the top pile but in the middle.2.According to the displacement of pile-soil foundation,we can obtain that the displacement of soil between piles is greater than the lateral.3.The stress is large at the top of piles under the seismic waves,so that we should pay more attention to that part in the designing and construction.4.Through exerting different seismic waves,we can see that the EI Centro wave can produce greater response in the same acceleration of earthquake.更多还原