Tapered piles responses during large-scale axial static and high-strain dynamic load testing

IF 5.6 1区 工程技术 Q1 ENGINEERING, GEOLOGICAL
Lars Bo Ibsen, Amin Barari
{"title":"Tapered piles responses during large-scale axial static and high-strain dynamic load testing","authors":"Lars Bo Ibsen,&nbsp;Amin Barari","doi":"10.1007/s11440-024-02507-5","DOIUrl":null,"url":null,"abstract":"<div><p>While significant research has focused on characterizing cylindrical piles with various shapes and material components, as well as their interaction with soil under axial loading, the performance of tapered piles under axial loading has received considerably less attention. Tapered piles provide an attractive alternative to conventional pile types such as driven steel and concrete straight piles, as they have improved the resistance during axial compressive loading. In this study, the performance of tapered piles under axial monotonic and impact loading was examined using laboratory testing. A series of large-scale static compression tests were performed on tapered piles with diameters of 76 and 89 mm under both saturated and unsaturated soil (Baskarp Sand No. 15) conditions. Each test consisted of multiple sub-tests to determine the in situ soil characteristics, and the key findings discussed here are based on results from pile bearing capacities after installation by jacking with an unloading/reloading step. Cone penetration tests were performed to quantify the effect of pile installation on the soil state for different initial relative densities. Dynamic pile testing, which is less costly and time-consuming than the static loading of large-scale piles, was performed with a hammer to assess the piles’ static load bearing capacities. The generalized relationship between static and dynamic bearing capacities was examined according to the Danish pile-driving formulas (DDRs) using the <i>j</i> factor. The results revealed that the DDRs can be used for saturated medium-dense sands with adequate confidence, whereas any application beyond this range may require thorough verification. The piles were then pulled out to enable the decoupling of friction resistance effects from base resistance.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 5","pages":"2307 - 2326"},"PeriodicalIF":5.6000,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Geotechnica","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11440-024-02507-5","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0

Abstract

While significant research has focused on characterizing cylindrical piles with various shapes and material components, as well as their interaction with soil under axial loading, the performance of tapered piles under axial loading has received considerably less attention. Tapered piles provide an attractive alternative to conventional pile types such as driven steel and concrete straight piles, as they have improved the resistance during axial compressive loading. In this study, the performance of tapered piles under axial monotonic and impact loading was examined using laboratory testing. A series of large-scale static compression tests were performed on tapered piles with diameters of 76 and 89 mm under both saturated and unsaturated soil (Baskarp Sand No. 15) conditions. Each test consisted of multiple sub-tests to determine the in situ soil characteristics, and the key findings discussed here are based on results from pile bearing capacities after installation by jacking with an unloading/reloading step. Cone penetration tests were performed to quantify the effect of pile installation on the soil state for different initial relative densities. Dynamic pile testing, which is less costly and time-consuming than the static loading of large-scale piles, was performed with a hammer to assess the piles’ static load bearing capacities. The generalized relationship between static and dynamic bearing capacities was examined according to the Danish pile-driving formulas (DDRs) using the j factor. The results revealed that the DDRs can be used for saturated medium-dense sands with adequate confidence, whereas any application beyond this range may require thorough verification. The piles were then pulled out to enable the decoupling of friction resistance effects from base resistance.

大尺度轴向静力和高应变动荷载试验中锥形桩的响应
在轴向荷载作用下,具有不同形状和材料构件的圆柱桩及其与土的相互作用的研究已经取得了显著进展,而锥形桩在轴向荷载作用下的性能研究却很少。锥形桩为传统的桩型(如打入钢桩和混凝土直桩)提供了一种有吸引力的替代方案,因为它们提高了轴向压缩加载时的阻力。本文采用室内试验的方法,对锥形桩在轴向单调荷载和冲击荷载作用下的性能进行了研究。在饱和土和非饱和土(Baskarp Sand No. 15)条件下,对直径为76和89 mm的锥形桩进行了一系列大型静压试验。每个测试都包括多个子测试,以确定原位土壤特性,这里讨论的关键发现是基于通过顶进和卸载/重新加载步骤安装后的桩承载能力的结果。在不同初始相对密度下,采用锥贯试验量化桩安装对土体状态的影响。采用锤击法对大型桩进行静载测试,评估桩的静载能力,这比大型桩静载测试成本低、耗时短。根据丹麦打桩公式(DDRs),用j因子检验了静、动承载力的广义关系。结果表明,ddr可用于饱和中密度砂,具有足够的信心,而任何超出此范围的应用可能需要彻底验证。然后拔出桩,使摩擦阻力效应与基础阻力解耦。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Acta Geotechnica
Acta Geotechnica ENGINEERING, GEOLOGICAL-
CiteScore
9.90
自引率
17.50%
发文量
297
审稿时长
4 months
期刊介绍: Acta Geotechnica is an international journal devoted to the publication and dissemination of basic and applied research in geoengineering – an interdisciplinary field dealing with geomaterials such as soils and rocks. Coverage emphasizes the interplay between geomechanical models and their engineering applications. The journal presents original research papers on fundamental concepts in geomechanics and their novel applications in geoengineering based on experimental, analytical and/or numerical approaches. The main purpose of the journal is to foster understanding of the fundamental mechanisms behind the phenomena and processes in geomaterials, from kilometer-scale problems as they occur in geoscience, and down to the nano-scale, with their potential impact on geoengineering. The journal strives to report and archive progress in the field in a timely manner, presenting research papers, review articles, short notes and letters to the editors.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信