{"title":"Resistance responses and design recommendations for driven piles in coarse-grained soil-based intermediate geomaterials","authors":"Nafis Bin Masud , Kam W. Ng , Shaun S. Wulff","doi":"10.1016/j.sandf.2023.101381","DOIUrl":null,"url":null,"abstract":"<div><p>Piles driven in Intermediate GeoMaterials (IGM) pose multiple design and construction challenges because of the high uncertainty in IGM properties, lacking knowledge pertaining to pile responses in IGM, and absence of classification, static analysis (SA) methods, and design recommendations. A classification criterion is established for coarse grained soil based intermediate geomaterials (CG-IGM) using test pile data from bridge projects completed in four U.S. states. This study improves our understanding of pile resistance responses in CG-IGM and results in pile design recommendations. Unit shaft resistance (<em>q<sub>s</sub></em>) of CG-IGM increases with the ratio of effective vertical stress (<span><math><mrow><msubsup><mi>σ</mi><mrow><mi>v</mi></mrow><mo>′</mo></msubsup></mrow></math></span>) to the ratio of corrected N-value, <em>(N<sub>1</sub>)<sub>60</sub></em>. Unit end bearing (<em>q<sub>b</sub></em>) increases with the ratio of. corrected N-value, <em>(N<sub>1</sub>)<sub>60</sub></em> to the effective vertical stress (<span><math><mrow><msubsup><mi>σ</mi><mrow><mi>v</mi></mrow><mo>′</mo></msubsup></mrow></math></span>). New SA methods are developed for predicting <em>q<sub>s</sub></em> and <em>q<sub>b</sub></em>. The proposed SA methods are compared against existing <em>β</em>-method developed for coarse grained soil and validated using an independent pile load test dataset. Pile setup is observed in <em>q<sub>s</sub></em> of piles driven in CG-IGMs, and pile relaxation is mostly observed in <em>q<sub>b</sub></em>. Statistical assessment concludes that the proposed SA methods provide more accurate and consistent <em>q<sub>s</sub></em> and <em>q<sub>b</sub></em> predictions than that by the <em>β</em>-method.</p></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0038080623001105/pdfft?md5=45f4bc232a3c64158cec2c4c8e4a1573&pid=1-s2.0-S0038080623001105-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Soils and Foundations","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0038080623001105","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, GEOLOGICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Piles driven in Intermediate GeoMaterials (IGM) pose multiple design and construction challenges because of the high uncertainty in IGM properties, lacking knowledge pertaining to pile responses in IGM, and absence of classification, static analysis (SA) methods, and design recommendations. A classification criterion is established for coarse grained soil based intermediate geomaterials (CG-IGM) using test pile data from bridge projects completed in four U.S. states. This study improves our understanding of pile resistance responses in CG-IGM and results in pile design recommendations. Unit shaft resistance (qs) of CG-IGM increases with the ratio of effective vertical stress () to the ratio of corrected N-value, (N1)60. Unit end bearing (qb) increases with the ratio of. corrected N-value, (N1)60 to the effective vertical stress (). New SA methods are developed for predicting qs and qb. The proposed SA methods are compared against existing β-method developed for coarse grained soil and validated using an independent pile load test dataset. Pile setup is observed in qs of piles driven in CG-IGMs, and pile relaxation is mostly observed in qb. Statistical assessment concludes that the proposed SA methods provide more accurate and consistent qs and qb predictions than that by the β-method.
期刊介绍:
Soils and Foundations is one of the leading journals in the field of soil mechanics and geotechnical engineering. It is the official journal of the Japanese Geotechnical Society (JGS)., The journal publishes a variety of original research paper, technical reports, technical notes, as well as the state-of-the-art reports upon invitation by the Editor, in the fields of soil and rock mechanics, geotechnical engineering, and environmental geotechnics. Since the publication of Volume 1, No.1 issue in June 1960, Soils and Foundations will celebrate the 60th anniversary in the year of 2020.
Soils and Foundations welcomes theoretical as well as practical work associated with the aforementioned field(s). Case studies that describe the original and interdisciplinary work applicable to geotechnical engineering are particularly encouraged. Discussions to each of the published articles are also welcomed in order to provide an avenue in which opinions of peers may be fed back or exchanged. In providing latest expertise on a specific topic, one issue out of six per year on average was allocated to include selected papers from the International Symposia which were held in Japan as well as overseas.