修正等应变假定下均匀开孔透水管桩复合地基固结解析解  

Analytical Solution for Composite Foundation with Permeable Pipe Piles Under Uniform Opening Based on Modified Equal Strain Assumption

作　　者：杨伟涛 陈征 段亚茹 梅国雄 YANG Weitao;CHEN Zheng;DUAN Yaru;MEI Guoxiong(School of Civil Eng.and Architecture,Guangxi Univ.,Nanning 530004,China;School of Civil Eng.and Architecture,Hainan Univ.,Haikou 570228,China;Guangxi Key Lab.of Disaster Prevention and Eng.Safety,Guangxi Univ.,Nanning 530004,China;Hainan Key Lab.of Marine Geological Resources and Environment,Haikou 570206,China;Ocean College,Zhejiang Univ.,Zhoushan 316021,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]海南大学土木建筑工程学院,海南海口570228 [3]广西防灾减灾与工程安全重点实验室,广西南宁530004 [4]海南省海洋地质资源与环境重点实验室,海南海口570206 [5]浙江大学海洋学院,浙江舟山316021

出　　处：《工程科学与技术》2024年第5期230-239,共10页Advanced Engineering Sciences

基　　金：国家自然科学基金项目(52178321,51878185);广西重点实验室开放课题项目(2022ZDK008);海南省自然科学基金青年基金项目(523QN213);海南省自然科学基金高层次人才项目(524RC476);海南大学科研启动基金项目(KYQD(ZR)-21067,RZ2200001147);海南省海洋地质资源与环境重点实验室开放课题项目(HNHYDZZYHJKF040)。

摘　　要：复合地基是一种有效且应用广泛的软土地基处理技术,而开孔透水管桩综合了散体材料桩的透水性与黏结材料桩高承载力的优点,是地基处理中增强体的新选择。据此,为研究透水管桩复合地基的固结特性,在考虑桩体向褥垫层和下卧层发生刺入的前提下对传统等应变假定进行了修正,并引入半透水边界作为桩土界面排水条件,在此基础上推导了桩身均匀开孔下土体固结的微分方程和求解条件,综合考虑了不同的附加应力分布形式以及扰动效应。利用有限正弦傅里叶变换等方法,求解了土体内部超静孔压、地基沉降及固结度的解析表达式,并通过退化分析和有限差分解的对比,验证了本文解答的正确性。最后,通过算例分析系统探究了开孔率、开孔半径、地基附加应力分布形式、扰动效应以及垫层和下卧层的压缩模量对地基固结特性的影响。结果表明:相比于传统管桩,透水管桩对加快桩周土内超静孔压的消散有着显著的效果;具体为开孔率越高、开孔半径越小,则桩侧土内超静孔压消散越快;与此同时,附加应力呈倒三角分布且不考虑扰动效应时地基固结速率最快;此外,增加垫层和下卧层的压缩模量也可以提升地基固结速率。本文的研究结果可为透水管桩技术的推广和工程设计提供一定的理论依据。Composite foundation is an effective technology for treating soft ground and is widely used in engineering practices.Permeable pipe piles combine the advantages of the permeability of granular piles with the high bearing capacity of adhesive columns,offering a new option for foundation reinforcement.The soil consolidation differential equations and definite solution conditions are established based on the modified equal strain assumption to explore the consolidation characteristics of a composite foundation treated by permeable pipe piles under external loads.This assumption considers the penetration depth of the pile into the cushion and underlying layer,where the permeable pipe pile-soil interface is regarded as an impeded boundary.Various forms of surcharge stress distribution and the disturbance effect are also considered.Then,the finite sine Fourier transform derives analytical solutions for the excess pore-water pressure in the soil element,settlement,and consolidation degree of the composite foundation.The validity of these solutions is confirmed by comparison to the degenerate case,and numerical solutions are calculated using the finite difference technique.Finally,the influences of factors such as the opening ratio,opening radius,distribution form of surcharge stress in the foundation,disturbance effect,and the compression modulus of the cushion and underlying layer on the consolidation characteristics of the composite foundation are investigated through parametric analyses.Compared to conventional pipe piles,the results showed that permeable pipe piles significantly accelerate the dissipation of excess pore-water pressure in the soil around the piles;the higher the opening ratio and the smaller the opening radius,the quicker the dissipation occurs.The fastest consolidation rate occurs when the surcharge stress is distributed in an inverted triangle,and the disturbance effect is not considered.In addition,the consolidation rate of the foundation increases with the increment of the compression modulus of

关 键 词：透水管桩 复合地基 固结 刺入变形 扰动效应 解析解 

分 类 号：TU472[建筑科学—结构工程]