摘要
超大直径空心独立复合桩基础是由空心桩、桩周水泥搅拌桩和桩周注浆土体共同承载的新型桩基础。为探明空心桩-注浆土-水泥搅拌桩相互作用机理,弄清桩周土体注浆、水泥搅拌桩对桩基承载力提高的影响程度,采用数值仿真方法,研究了超大直径空心独立复合桩基础的竖向和横向承载特性,分析了该新型基础的结构实用性。研究表明,桩周注浆和桩周注浆+水泥搅拌桩对桩承载力提高影响明显,竖向承载力分别提高了7.4%、12.1%,横向承载力分别提高了7.2%、14.4%;竖向荷载作用下,超大直径空心独立复合桩的桩侧阻力占桩顶荷载比重为84.0%,表现出典型的摩擦桩特性;横向荷载作用下,超大直径空心独立复合桩绕距桩顶23.4m处的桩身截面产生了转动,表现出刚性桩特性,研究成果可为超大直径空心独立复合桩基的设计施工提供理论依据与技术支持。
Hollow-diameter hollow composite foundation is a new type of pile foundation which is coborne by hollow piles,pile-circumference cement mixing piles and grouting soil around piles.In order to study the interaction mechanism of hollow piles-grouting soil-cement mixing piles,and to clarify the influence degree of soil grouting and cement mixing piles on the improvement of bearing capacity of piles,finite element software Marc is used.The vertical axial and transverse axial bearing characteristics of the super-large-diameter hollow composite foundation are studied,and the structural practicability of the new foundation is analyzed.The results show that the effect of pile grouting and pile grouting+cement mixing pile on the pile bearing capacity are obvious.The vertical bearing capacity increases by 7.4%and 12.1%respectively,and the horizontal bearing capacity increases by 7.2%and 14.4%respectively.Under the vertical axial load,the lateral resistance of the pile accounts for 84.0%of the top of the pile,which shows typical characteristics of the friction pile.Under the horizontal axial load,the pile rotates around the pile section at 23.4 m from the top of the pile showing the characteristics of the rigid pile.The research results can provide theoretical basis and technical support for the design and construction of large diameter hollow composite foundation.
作者
冯忠居
董芸秀
戴良军
崔林钊
文军强
冯凯
FENG Zhong-ju;DONG Yun-xiu;DAI Liang-jun;CUI Lin-zhao;WEN Jun-qiang;FENG Kai(School of Highway,Chang'an University,Xi'an710064,China;School of Civil Engineering,Longdong University,Qingyang745000,China;Anhui Construction Engineering Group,Hefei230000,China)
出处
《公路》
北大核心
2019年第4期95-104,共10页
Highway
基金
中央高校基本科研业务费资助项目
项目编号300102218115
关键词
岩土工程
超大直径
空心独立复合桩
施工工艺
数值模拟
承载特性
研究
geotechnical engineering
super large diameter
hollow independent composite pile
construction technology
numerical simulation
bearing performance
study
