Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1595994
Alexandre P. R. P. Almeida, Jinyuan Liu
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.
本文对安大略省土体中两种微桩设计方法的性能进行了评价，即修正的联邦公路管理局方法([2000])。微桩设计施工指南及实施手册。报告没有。FHWA-SA-97-070, United States Department of Transportation, 376 p.)和Bustamante and Doix方法(1985)。一个混和器的混和器的混和器的混和器的混和器。Bull Liaison Lab Ponts Chauss, Ministere de l' equipment, du logement, de l' management du territire et des transportation, Paris, 140, pp. 75-92)。微桩是一种小直径、高配筋的灌浆桩。由于与传统桩相比，微桩存在更高的不确定性，设计方法倾向于预测其岩土极限承载力的较大变化。微桩的设计很大程度上依赖于荷载试验结果和设计人员的工程判断。本研究分析了由Keller Foundations Ltd进行的总计47个全尺寸微桩荷载试验，以确定最适合的设计方法来预测安大略省土壤中微桩的岩土承载力。由于大多数试验在达到破坏阶段之前就终止了，因此首先外推荷载-位移曲线以获得破坏荷载。比较了每种方法的预测精度和变化。根据研究结果，联邦公路管理局的方法在考虑Bustamante和Doix方法建议的直径膨胀参数的基础上进行了修改，为安大略省土壤的岩土承载力提供了合理的估计。
{"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}
Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1588536
Marco Chiarabelli, S. Miranda, Federico Pagliacci
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.
{"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}
Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1595996
G. Spagnoli, Cristina de Hollanda Cavalcanti Tsuha, P. Oreste, Carlos Mauricio Mendez Solarte
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.
{"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}
Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1595993
T. Siegel, T. J. Day, B. Turner, P. Faust
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.
{"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}
Pub Date : 2018-09-02DOI: 10.1080/19375247.2018.1547352
{"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}
Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1588535
J. Crispin, Colm P. Leahy
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.
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Pub Date : 2018-09-02DOI: 10.1080/19375247.2019.1592893
A. Lemnitzer, T. Siegel
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
亲爱的杂志读者们，我们很高兴为大家呈现一份真正的国际杂志，特别注重基础设计的实用，并收集了大量的案例研究。我们的问题从2018年DFI学生论文比赛的获胜者Alexandre Almeida开始，他是加拿大多伦多瑞尔森大学的研究生。亚历山大和他的导师刘金元教授都是土木工程系的，他们研究了总共47个全尺寸微桩荷载试验，以确定最适合的设计方法来预测安大略省土壤中微桩的岩土承载力。该研究揭示了联邦公路管理局(2000)的方法，该方法经Bustamante和Doix(1985)提出的考虑直径膨胀参数的修改，为安大略省土壤的岩土承载力提供了最合理的估计。Alexandre Almeida在加利福尼亚州阿纳海姆举行的第43届DFI年会的青年专业会议上展示了他的作品。Chiarabelli, Miranda和Pagliacci跨越了从加拿大到土耳其的各个大洲，介绍了为土耳其伊斯坦布尔的Galataport项目提供特殊岩土工程解决方案所使用的技术和性能控制。综合工程包括地下连续墙的建设、深基础系统、液化缓解和脱水系统的实施。文中描述了两个遗址，其中一个遗址还要求对遗址内的历史建筑进行保护。本文介绍了从设计到施工的宝贵细节，并强调了在大面积建筑空间中使用最先进的地面改进技术。此外，还介绍了在初步现场试验期间和工作完成后对改良土壤进行的现场和实验室测试的结果。2018年学生论文竞赛的亚军得主Jamie John Crispin和他的博士导师Colm Leahy教授都来自布里斯托尔大学，他们提供了一种封闭形式的解析解，用于推导嵌入在非均匀土壤中的群配置桩之间的相互作用因素。该方法适合在面向设计的软件包中实现，作者还提供了用于手工计算的设计图。此外，作者开发了一种简化的方法，结合误差校正因子，将简化方法与复杂解析解之间的差异减少到10%以下。该分析工具是最理想的实际配置，并已证明有很好的协议与实验结果。Crispin是在加利福尼亚州阿纳海姆举行的第43届DFI年会上获得该奖项的。Spagnoli、Tsuha、Oreste和Mendez Solarte发表了一项关于不同螺旋轴比的螺旋桩抗拔能力的敏感性研究。作者考虑了两种抬升能力方程和两种扭矩模型。选取了典型数值模拟北海近海粘土的土壤性质。在不排水条件下进行了分析，模拟了安装过程中的扭转阻力和短期桩容。作者还进行了蒙特卡罗模拟，以评估评估设计深度的岩土参数的可变性。对比分析的结果表明，螺旋桩在海上环境中的潜在应用(即本研究中考虑的桩径)高度依赖于用于计算深度和扭矩的岩土模型。本问题以Siegel、Day、Turner和Faust的技术说明结束，他们提出了旧金山海湾地区粘土中连续飞行螺旋桩和钻孔位移桩的末端阻力的局部关系。通过对现浇桩进行的15次高质量轴压加载试验，将充分动员的端阻力与桩尖以下一直径的平均净锥阻力进行了比较。对这些测试数据的解释表明，使用轴承2018/19 DFI董事会的可接受方法
{"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}
Pub Date : 2018-05-04DOI: 10.1080/19375247.2018.1562599
Abigail Stein, Aled Hughes, R. Deschamps, B. D. Barkauskas
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.
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Pub Date : 2018-05-04DOI: 10.1080/19375247.2018.1562664
A. Lemnitzer, T. Siegel
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
{"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}
Pub Date : 2018-05-04DOI: 10.1080/19375247.2018.1562598
Alireza Kordjazi, J. Coe, Siavash Mahvelati
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.
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