岩溶地区新型灌注桩承载机理试验及模拟研究  

Experiment and Simulation Research on Bearing Mechanism of a New Type Grouted Pile in Karst Area

作　　者：梅国雄[1,2,3] 陆志宇 陈家勋 张福友 杨济铭 蒋明杰 MEI Guoxiong;LU Zhiyu;CHEN Jiaxun;ZHANG Fuyou;YANG Jiming;JIANG Mingjie(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education(Guangxi University),Nanning 530004,China;Guangxi Key Laboratory of Disaster Prevention and Engineering Safety(Guangxi University),Nanning 530004,China;Guangxi Xinfazhan Communication Group Co.Ltd.,Nanning 530029,China;Guangxi Transportation Science and Technology Group Co.Ltd.,Nanning 530007,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004 [2]工程防灾与结构安全教育部重点实验室(广西大学),广西南宁530004 [3]广西防灾减灾与工程安全重点实验室(广西大学),广西南宁530004 [4]广西新发展交通集团有限公司,广西南宁530029 [5]广西交科集团有限公司,广西南宁530007

出　　处：《湖南大学学报（自然科学版）》2022年第7期32-44,共13页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51578164,51878185,52168046,52108309);广西研究生教育创新计划资助项目(YCSW2019046)。

摘　　要：基于布袋桩成桩试验与4组室内静载荷试验,结合7组数值模型,对布袋桩的成桩可行性与桩身荷载的传递特性及其承载机理进行研究.结果表明:1)布袋桩在解决岩溶地区成桩时浆液渗漏问题的同时,具有成桩质量良好、成桩形状可预测的特征.在等桩径、等加载条件下,布袋桩的极限承载力为传统桩的1.15倍以上,桩顶沉降远小于传统桩;2)布袋桩承载时,各段桩体从上至下依次发挥作用,交替承载.枝状体的端承作用对承载力的增益大于布袋对侧摩阻力的削弱,此为布袋桩的承载特征;3)枝状体结构增强了桩-岩间的结合能力,其中,枝状体下部起主要承载作用,上部仅起结构作用;4)枝状体的非对称分布是承载的不利因素之一,对布袋桩的抗弯能力提出设计要求.试验及数值模拟结果展示了布袋桩的成桩过程,揭示了布袋桩独有的承载机理,验证了布袋桩承载性能的优越性,可为布袋桩在岩溶地区的应用提供思路和依据.Based on the bag-sealed pile formation test and four sets of indoor static load tests,combined with seven sets of numerical models,the feasibility of pile formation,pile load transfer characteristics and load-bearing mechanism of bag-sealed piles were studied.The research results show that:1)The bag-sealed pile has the characteristics of good pile quality and predictable pile shape while solving the problem of slurry leakage during pile formation in karst areas.Under the conditions of equal pile diameter and equal loading,the ultimate bearing capacity of the bag-sealed pile is more than 1.15 times that of the traditional pile,the settlement of the pile top is much smaller than that of the traditional pile;and the settlement of the pile top is much smaller than that of the latter.2)When the bag-sealed pile is loaded,each pile section plays in turn from top to bottom and carries the load alternately.The enhancement of the end-bearing effect of the branched section on the load bearing capacity is greater than the weakening of the bag on the side friction resistance,which is the load-bearing characteristics of the bag-sealed pile.3)The branched section enhances the pile-rock bonding capacity,in which the lower part of the branched section plays the main bearing role and the upper part only plays the structural role.4)The asymmetric distribution of the branched sections is one of the unfavorable factors for load bearing,which puts forward a requirement for the design of the bending resistance of the bag-sealed pile.The experimental and numerical simulation results demonstrate the pile formation process of the bag-sealed pile,reveal its unique bearing mechanism and verify its superiority of bearing performance.The research findings can provide ideas and bases for the application of bag-sealed piles in karst areas.

关 键 词：岩溶地区 桩基工程 传递特性 有限元 承载机理 

分 类 号：TU318[建筑科学—结构工程]