DFI Journal - The Journal of the Deep Foundations Institute最新文献

{"title":"Statistical evaluation of design methods for micropiles in Ontario soils","authors":"Alexandre P. R. P. Almeida, Jinyuan Liu","doi":"10.1080/19375247.2019.1595994","DOIUrl":"https://doi.org/10.1080/19375247.2019.1595994","url":null,"abstract":"This paper evaluates the performance of two design methods for micropile in Ontario soils: namely the modified Federal Highway Administration method ([2000]. Micropile design and construction guidelines implementation manual. Report no. FHWA-SA-97-070, United States Department of Transportation, 376 p.) and the Bustamante and Doix method ([1985]. Une méthode pour le calcul des tirants et des micropieux injectés. Bull Liaison Lab Ponts Chauss, Ministere de l'equipement, du logement, de l'amenagement du territoire et des transports, Paris, 140, pp. 75–92). Micropiles are small-diameter, grouted piles installed with high amount of steel reinforcement. Since a higher level of uncertainty exists in micropiles compared to conventional piles, design methods tend to predict a large variation in their geotechnical ultimate capacities. The design of a micropile is extremely dependent on the load test results and the engineering judgement of designers. This research analysed a total of 47 full-scale micropile load tests conducted by Keller Foundations Ltd to determine the most suitable design method to predict the geotechnical capacity of a micropile in Ontario soils. Since most tests terminated before reaching the failure stage, the load-displacement curves were first extrapolated to obtain the failure load. The accuracy and variation of the predictions were compared for each method. From the findings, the Federal Highway Administration method, modified with a consideration of diameter expansion parameter suggested by Bustamante and Doix method, provided reasonable estimations for the geotechnical capacities in Ontario soils.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127561709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The deep soil mixing for the Galataport project in Istanbul, Turkey","authors":"Marco Chiarabelli, S. Miranda, Federico Pagliacci","doi":"10.1080/19375247.2019.1588536","DOIUrl":"https://doi.org/10.1080/19375247.2019.1588536","url":null,"abstract":"The paper describes the adopted technologies and performance controls related to a special geotechnical engineering solution provided within the scope of the Galataport Project, in Istanbul, Turkey. The scheme is the one applied to the new quay of Salıpazarı, which is a combination of retaining structure and ground improvement, formed by a combi-wall, a reinforced concrete diaphragm wall and a soil improvement by deep soil mixing (Turbojet). The paper highlights the importance of employing cutting-edge technologies within the foundation engineering field and state-of-the-art electronic control devices, in parallel with the essential human expertise, in order to obtain the desired results in this high-profile Project. A cross section of the executed treatment could be inspected on site during excavation, which shows the effectiveness of the executed works. The results of the in-situ and laboratory tests carried out on the improved soil during the preliminary field trial test and after the completion of works are also presented.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"309 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126616067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A sensitivity analysis on the parameters affecting large diameter helical pile installation torque, depth and installation power for offshore applications","authors":"G. Spagnoli, Cristina de Hollanda Cavalcanti Tsuha, P. Oreste, Carlos Mauricio Mendez Solarte","doi":"10.1080/19375247.2019.1595996","DOIUrl":"https://doi.org/10.1080/19375247.2019.1595996","url":null,"abstract":"The potential application of offshore helical pile systems is currently under the attention of the geotechnical community. This paper considers a theoretical analysis of different helical piles with helix-to-shaft ratios (i.e. wing ratio) of 1.5, 2.0 and 2.5 with a constant shaft diameter of 500 mm installed in clays with different undrained shear strength values up to 500kPa and two different sensitivity values. Three different maximum uplift capacity values (10, 15 and 20 MN) have been hypothesised. Two uplift capacity equations have been used and compared among each other to assess the maximum installation depth to reach the required uplift capacity values. Torque assessment has been also performed using two different models. Results show that if sensitivity is considered during the design as a result of pile installation, pile design depths reduce. Torque values tend to reduce too, as the remoulded clay is less resistant. Power assessment has been also obtained from the torque values using the theory of Tresca. A Montecarlo analysis was also performed to show how the uncertainties of the geotechnical parameters influence the installation depth based on the required uplift force.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122021657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measured end resistance of CFA and drilled displacement piles in San Francisco Area alluvial clay","authors":"T. Siegel, T. J. Day, B. Turner, P. Faust","doi":"10.1080/19375247.2019.1595993","DOIUrl":"https://doi.org/10.1080/19375247.2019.1595993","url":null,"abstract":"Continuous Flight Auger (CFA) and drilled displacement (DD) piles in the San Francisco (California, USA) area are typically designed using a combination of side- and end resistances. For moderately-sized buildings, these piles are typically 50 to 100 ft (about 15 to 30 m) in length and often bear in Pleistocene epoch alluvium consisting primarily of clay with interbedded sand seams. It can be unconservative to rely upon the higher consistency sand seams because their depth, thickness, and consistency can vary dramatically over short distances. A more robust design approach assigns an end resistance based on the strength of the clay. The fully mobilised end resistance from fifteen (15) high quality axial compression loading tests performed on cast-in-place piles are compared to the average net cone resistance for one diameter below the pile tip. The comparison suggests that direct estimation of the end resistance using local load testing data will result in higher end resistances than will the conventional bearing factor of 9 times the estimated undrained shear strength derived from the cone penetration test.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116998055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DFI Journal Underwriters","authors":"","doi":"10.1080/19375247.2018.1547352","DOIUrl":"https://doi.org/10.1080/19375247.2018.1547352","url":null,"abstract":"","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120961095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Settlement of axially loaded pile groups in inhomogeneous soil","authors":"J. Crispin, Colm P. Leahy","doi":"10.1080/19375247.2019.1588535","DOIUrl":"https://doi.org/10.1080/19375247.2019.1588535","url":null,"abstract":"Accurate prediction of settlement is key to performance-based design of pile groups. Simple methods based on physically motivated modelling assumptions, in conjunction with wisely chosen soil material constants, can accurately predict settlements without having to perform complex numerical analysis in three dimensions. Interaction factors, introduced by Poulos, simplify the analysis of pile groups through superposition of the effects of only two piles at a time. Closed-form solutions for interaction factors between piles in homogeneous soils are available in the literature, incorporating both the displacement field around a single pile and the reinforcing effect of a second pile. This paper will investigate pile groups embedded in inhomogeneous soils with shear modulus varying with a power law function of depth. The problem is formulated by considering the response of a ‘receiver’ pile carrying no load at its head, subjected to the displacement field of a loaded ‘source’ pile. A simplified approximate expression is developed using a model error correction factor that is suitable for routine design use. The performance of the proposed model at predicting experimental results is investigated. Dimensionless design charts and an illustrative example are provided.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126676253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial Note – Issue 3 (2018)","authors":"A. Lemnitzer, T. Siegel","doi":"10.1080/19375247.2019.1592893","DOIUrl":"https://doi.org/10.1080/19375247.2019.1592893","url":null,"abstract":"Dear Journal readers, we are pleased to present a truly international issue of the DFI Journal with a particularly practical focus on foundation design and a collection of great case studies. Our issue begins with the 2018 DFI student paper competition winner, Alexandre Almeida, a graduate student at Ryerson University in Toronto, Canada. Alexandre and his advisor, Professor Jinyuan Liu, both in the Department of Civil Engineering, studied a total of 47 full-scale micropile load tests to determine the most suitable design method to predict the geotechnical capacity of micropiles in Ontario soils. The study revealed the Federal Highway Administration (2000) method, modified with a consideration of diameter expansion parameter, as suggested by Bustamante and Doix (1985), to provide the most reasonable estimations for the geotechnical capacities in Ontario soils. Alexandre Almeida presented his work in the Young Professional session during the 43 Annual DFI conference in Anaheim, California. Moving across continents, from Canada to Turkey, Chiarabelli, Miranda, and Pagliacci, describe the technologies and performance controls utilised to provide a special geotechnical engineering solution for the Galataport Project, in Istanbul, Turkey. The comprehensive project includes the construction of diaphragm walls, deep foundation systems, liquefaction mitigation, and implementation of dewatering systems. Two sites are described in the paper, while one of the sites also required the preservation of historical buildings on site. The paper presents valuable details from design to construction and highlights the use of state-of-the-art technologies for ground improvement on large areas of construction space. In addition, results of in-situ and laboratory tests carried out on the improved soil during the preliminary field trial test and after the completion of work are presented. Jamie John Crispin, the runner-up award winner of the 2018 student paper competition, and his Ph.D. advisor Professor Colm Leahy, both at the University of Bristol, provide a closed-form analytical solution for the derivation of interaction factors between piles in a group configuration embedded in inhomogeneous soil. The method is suitable for implementation in a designoriented software package and design charts have been provided by the authors for use in hand calculations. In addition, the authors developed a simplified methodology which, combined with an error correction factor, reduces the discrepancy between the simplified method and the complex analytical solution to less than 10%. This analytical tool is ideal for most practical configurations and has shown to have good agreement with experimental results. Crispin received his award during the 43rd DFI annual conference in Anaheim, CA. Spagnoli, Tsuha, Oreste, and Mendez Solarte present a sensitivity study on the uplift capacity of helical piles with different helix to shaft ratios. Two uplift capacity equations and two torque ","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"282 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115989404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wanapum Dam repaired using post-tensioning anchors","authors":"Abigail Stein, Aled Hughes, R. Deschamps, B. D. Barkauskas","doi":"10.1080/19375247.2018.1562599","DOIUrl":"https://doi.org/10.1080/19375247.2018.1562599","url":null,"abstract":"In central Washington, the flow of the Columbia River is harnessed by the Wanapum Dam which is part of the Priest Rapids Hydroelectric Project owned and operated by Grant County Public Utility District (GCPUD). The dam extends approximately 8300 feet from bank to bank and includes earth embankments, concrete gravity sections and a 10 unit powerhouse. Adjacent to the right embankment is a concrete gravity spillway featuring radial gates measuring 50-feet wide and nearly 70-feet high. In the early 1960s, when built, these seven-story spillway gates were the highest in the world. In February 2014, during a routine maintenance inspection, observant workers noticed a slight misalignment in the roadway deck curbs and handrails on top of the spillway. Further investigation uncovered a 65-foot long by 2-inch wide crack that spanned the full length of Monolith 4. Due to the potential risks of a catastrophic failure, GCPUD immediately drew down the reservoir and began work on developing an emergency remedial procedure to repair the crack in the dam. Sixty-one-strand post-tensioned anchors, underwater Ogee Spillway bar anchors and a grouting program to seal the crack were among the main techniques performed to repair the Dam. This case study will address in detail the successful use of these techniques.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"119 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116931714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial Note – Issue 2 (2018)","authors":"A. Lemnitzer, T. Siegel","doi":"10.1080/19375247.2018.1562664","DOIUrl":"https://doi.org/10.1080/19375247.2018.1562664","url":null,"abstract":"Dear Journal Readers, DFI’s 2018 Issue #2 is a great mix of research papers, award papers, case studies, and submissions with honorable mentions received during DFI annual conference’s paper competition. Our broad mix of local and international authors will keep you interested across a broad spectrum of research and project topics and provide practical knowledge in foundation engineering, quality assurance & testing, and in-situ investigations. This issue starts with a fresh look at a regionally developed, but nationally integrated design method, the Texas Cone Penetration (TCP) foundation design method. Moghaddam, Jayawickrama, Lawson, Surles, and Seo conduct a qualitative and quantitative assessment of the predictive validity of the TCP method based on 60 full scale load test datasets. The authors suggest that the TCP foundation design method can yield a foundation element that, when evaluated based on soil strength may not seem highly reliable, but when evaluated based on serviceability considerations (i.e., tolerable displacement) will perform exceedingly well to the point of perhaps being considered over-designed. This paper provides insight into a long-standing discussion among foundation engineers who have voiced questions about the reliability of the TCP method based on their own experiences where the method may seem to over-predict soil shear strength. The case study on the Wanapum Dam repair prepared by the author team Stein, Hughes, Dechamps and Barkauskas presents the challenges and success story of a unique underwater repair work using post-tension anchoring systems. The dam and surrounding areas were closed after severe cracking with up to 2inch width and 65 ft length was observed in one of the dam’s monoliths. The paper describes the design review, potential damage causes, repair strategies and a step-bystep description of the construction and remedy procedures. The paper was presented during DFI’s 43rd annual conference in Anaheim. Dr. Alessandro F. Rotta Loria was the winner of DFI’s 2018 young professor paper competition. Dr. Rotta Loria is a post-doctoral researcher at the Swiss Federal Institute of Technology in Lausanne, EPFL, and will soon commence his role as assistant professor at Northwestern University in Chicago. His research focuses on the multi-physical behavior and performance of energy foundations. His paper presents a performance-based design framework for energy piles and suggests that thermal loads involve effects that can be neglected in the design of energy piles at ultimate limit states and can be considered relevant only at serviceability limit states. Based on his finding, the performance-based design of energy piles at ultimate limit states reduces to a conventional pile design process while the design at serviceability limit states must account for a number of proposed verifications. Dr. Rotta Loria’s presentation of this paper is available online at https://m. youtube.com/watch?v=Hmi9lYfK3do. A critical r","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115957876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in stress-wave nondestructive testing methods for evaluation of deep foundations","authors":"Alireza Kordjazi, J. Coe, Siavash Mahvelati","doi":"10.1080/19375247.2018.1562598","DOIUrl":"https://doi.org/10.1080/19375247.2018.1562598","url":null,"abstract":"Stress-wave based nondestructive testing (NDT) systems such as cross-hole sonic logging (CSL), low strain integrity testing, and ultrasonic echo devices (e.g. Sonicaliper) are routinely deployed for quality assurance (QA) and quality control (QC) of deep foundation systems. However, there are still a number of scenarios where the current standard of practice for QA/QC can fail to provide sufficient information regarding a deep foundation system. For example, limited information can be obtained regarding in-service pile and drilled shaft integrity. Additionally, conditions beneath drilled shafts excavations are not well characterised unless a significant amount of probing is performed, particularly if the shaft diameter is large. This paper introduces recent advances in stress-wave NDT systems for use in assessments of in-service foundation integrity and drilled shaft construction. A borehole testing system was developed in a laboratory setting as a proof-of-concept study to generate high-resolution images of defects in deep foundations. The probe, emitting and detecting stress waves with ultrasonic frequency content, is capable of non-destructively imaging the outer perimeter/circumference of in-service or newly constructed foundations without any need for foundation instrumentation. The foundation elements in the experimental model were constructed with practical cross-sectional dimensions to simulate real field conditions with defects due to corrosions and poor concrete placement practice. The primary results of the experiment are very promising, even with a simple data processing technique applied on the acquired raw data, as the acquired image was capable of differentiating changes in the section as low as 0.3 cm. The same hardware components were incorporated into a down-hole testing system developed to identify the location of anomalous features beneath drilled shaft excavations in karst. The preliminary results on a relatively large scale cemented sand model were also promising. Numerical modelling was also performed to evaluate the issues involved in scaling the system for field applications and evaluating more complex subsurface conditions using a full waveform inversion technique. A brief overview is provided of both systems including hardware, survey methods, and data processing techniques, followed by a discussion on application of the results to QA/QC of deep foundations.","PeriodicalId":272645,"journal":{"name":"DFI Journal - The Journal of the Deep Foundations Institute","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121287351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}