摘要
文章利用室内半模试验和颗粒流理论对比分析多层土地基扩底单桩与群桩的抗压、抗拔承载特性及变形特征,并对比分析了扩底桩的荷载-位移曲线。结果表明,群桩的抗压、抗拔承载能力均大于单桩。抗压群桩桩间距从1.125 D(D为扩大头直径)增加到2.250D时,荷载增长率为4.39%;超过2.250 D后荷载增长率趋缓,在1/2极限荷载作用下,群桩桩顶位移比单桩大0.37 mm,而承载力比单桩增加了46.59%;极限荷载作用下,桩顶位移基本一致,群桩的极限承载力比单桩极限承载力大266 N。抗拔群桩间距分别为1.125 D、1.250D、1.750D、2.250D时,与相同持力层厚度单桩相比,其抗拔极限承载力分别增加40.94%、59.38%、87.11%、88.57%。抗压单桩和群桩桩身轴力沿着桩身深度的增加方向均呈现凸曲线减小趋势。桩身深度相同的情况下,从细观角度分析揭示了群桩综合承载能力大于单桩。
This paper uses the indoor half-model test and the particle flow theory to compare and analyze the compressive and uplift bearing characteristics and deformation characteristics of the multi-layered soil foundation belled single piles and pile groups,and compares and analyzes the load-displacement curve of the belled piles.The results show that the compressive and uplift bearing capacity of pile groups is greater than that of single piles.When the pile spacing of compressive pile groups increases from 1.125 D(D is the diameter of the enlarged head)to 2.250 D,the load growth rate is 4.39%;after 2.250 D,the load growth rate slows down.Under the action of 1/2 ultimate load,the displacement of the pile top of pile groups is 0.37 mm larger than that of a single pile,and the bearing capacity is 46.59% higher than that of a single pile.Under the ultimate load,the displacement of the pile top is basically the same,and the ultimate bearing capacity of pile groups is 266 N larger than that of a single pile.Compared with single piles with the same bearing layer thickness,when the pile spacing of uplift pile groups is 1.125 D,1.250 D,1.750 D,and 2.250 D,the ultimate uplift bearing capacity of piles increases by 40.94%,59.38%,87.11%,and 88.57%,respectively.The axial force of the compressive single piles and pile groups shows a convex curve decreasing along the increasing direction of the pile depth.In the case of the same pile depth,a meso-level analysis reveals that the comprehensive bearing capacity of pile groups is greater than that of single piles.
作者
李飞
杨俊杰
孙涛
宋建东
LI Fei;YANG Junjie;SUN Tao;SONG Jiandong(Key Laboratory of Marine Environment and Ecology of Ministry of Education,Ocean University of China,Qingdao 266100,China;College of Environmental Science and Engineering,Ocean University of China,Qingdao 266100,China;Changda Building Technology Co.,Ltd.,Weifang 261000,China;College of Earth Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《合肥工业大学学报（自然科学版）》
CAS
北大核心
2021年第9期1227-1236,共10页
Journal of Hefei University of Technology：Natural Science
基金
国家自然科学基金资助项目(51779235)
国家自然科学基金青年基金资助项目(41602322)
山东科技大学人才引进科研启动基金资助项目(2015RCJJ010)。
关键词
扩底桩
竖向承载特性
多层土地基
颗粒流程序(PFC)
belled pile
vertical bearing characteristics
multi-layered soil foundation
Particle Flow Code(PFC)
