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By Sastry Putcha, Santosh Mummaneni, Swamy Avasarala, Vamshi Vemula

"This paper presents the results from a case study on the comparison of two strain acquisition instrumentation technologies, Geokon rebar strainmeters and Embedded Data Collectors (EDC) for the DC Water Main Pump Station project, in Washington D.C. These two instrumentation systems were installed by AVER in a single 18-inch (0.45 m) diameter augercast pile (with one-1.25 inch (3.175 cm) dywidag bar) at critical locations to determine the load transfer mechanism and establish a comparison between strain/load measured with these two systems along the pile. A quick static load test was performed on the test pile as per ASTM D1143 standard.Prior to the installation of the pile, a 24-inch (0.6 m) diameter outer casing was installed to the proposed cutoff elevation of -22.5 feet (-6.85 m) to discount the frictional resitance within the upper overburden zone. The pile was then drilled through the outer casing to the tip elevation of -65.02 feet (-19.8 m) with inner casing within the overburden zone. Strainmeters along with EDC were installed on dywidag bar at various locations and then wet set into the concrete following auger retrieval. The loads measured with EDC and Geokon sensors were within 15% percent of each other.PROJECT BACKGROUNDProject Background & Requirements:Like any other foundation piles, augercast piles are extensively used in the public and private sector structures in the United States for many years. It is a common practice to perform static compression (ASTM D1143), tension (ASTM D3689), and lateral load tests (ASTM D3966) depending on the project requirements. In recent years, embedded strain sensors, manufactured by Smart Structures, USA has gained prominence for its use to collect both static and dynamic measurements for driven piles. In addition, AVER has successfully used EDC for collecting long term static measurements for an abutment drilled shafts for I-95 Hotlanes project in Virginia, USA.Geokon sisterbar strain gages are widely used in the foundation industry to monitor the load transfer mechanism within pile foundations throughout the world. As the Geokon strainmeters are vibrating wire and are welded to a sister bar, there is often a debate within the engineering community with regards to what modulus to use when converting measured strains to loads. EDC sensors, unlike Geokon strain gages are embedded directly into the concrete and therefore do not have the same concern."

Jan 1, 1900

By Filippo Maria Leoni, Alessandro Bertero, Gianluca Pianezze

"As part of the Southeast Louisiana (SELA) drainage program, designed by the U.S. Army Corps of Engineers (USACE) to reduce flood damages in the City of New Orleans and surrounding parishes through the construction of new pumping stations and better drainage canals, the SELA-22 project entailed the installation of a concrete covered canal along Jefferson Ave. and Prytania Street, in a highly urbanized portion of Uptown New Orleans, LA. The scope of the required soil improvement was to replace the soil between two parallel lines of sheet piles with a soil-cement mass to eliminate underseepage and provide structural support for the concrete culvert. The USACE selected the jet grouting (Jet Grout) technology for the construction of the bottom plug. The bottom plug is between 18 and 21.5 ft thick with a maximum depth of approximately 40 ft, for a total length of approximately one mile. The treated soil comprised soft clays and silts with occasional presence of sands. Project specifications required 100% area coverage, a 28-days unconfined compressive strength of 100 psi and hydraulic conductivity of 1x10-6 cm/s, to be verified by testing specimens from cored samples. The specialty geotechnical contractor proposed to accomplish the task utilizing their proprietary and innovative elliptical bi-fluid Jet Grout technology, and elected to perform a pre-construction bench scale laboratory mixing program to determine the most suitable grout mix features (i.e. binder type and proportions, binder content, etc.) to be applied in the subsequent field test and production stages. This paper will summarize and compare the results obtained from the different pre-construction and construction stages; interpretations of the data will be provided, along with general considerations regarding the effectiveness and significance of bench scale testing for jet grouting applications.INTRODUCTIONIn general, the effectiveness of the construction parameters in any ground improvement work depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product."

Jan 1, 2016

By Paul A. O’Brien, Gary A. Chapman, Thomas G. Cuniowski

"The new Amcor B9 paper mill in Botany, NSW, Australia, involved the design and construction of a new paper mill founded within the Botany Basin Sediments. There were numerous design and construction challenges to address, including tight settlement tolerances for the paper machine footings (6 mm total and 1/2000 mm differential limits), high variable and cyclic loads, deep (>25 m) bedrock and uncontrolled fill material across the site. The mill structure design incorporated a deep driven precast and CFA piled foundation solution, with a comprehensive swathe of testing to validate pile capacity and expected settlements. The pile design for the mill structure included the installation of approximately 1000 piles, with pile testing comprising dynamic testing and a static load test on precast piles. With consideration of Sydney’s increasing demand for development space in relative close proximity to the city’s CBD, industrial areas in the Botany Bay area are likely to make way for heavy or complex commercial and residential structures. Therefore, a better understanding of the engineering behaviour of sediments underlying these areas would allow for efficient foundation solutions. This paper presents a discussion on effective foundation testing techniques and the effects that the behaviour and characteristics of the Botany Bay sediments impose on deep piled solutions.2 PROJECT DETAILS2.1 New paper millThe project involved the construction of the largest recycled paper machine in Australia. The paper machine is 330 m (1080 ft) long, 22 m (72 ft) high, and capable of producing 1.6 km (1 mile) of paper per minute. Construction commenced in early 2011 and new paper mill officially opened in early 2013. The early works contract was awarded to Baulderstone Construction Pty. Ltd. (Lend Lease Corp. Ltd.), with the D&C contract awarded to a consortium headed by Leighton Contractors Pty. Ltd. (CPB Contractors Pty. Ltd.), which included Golder Associates Pty. Ltd. as the geotechnical designer and reviewer.2.2 Site history and effect on local topographyThe site has been used as a paper mill since 1902, and as such, has layers of uncontrolled fill and buried objects within the upper fill materials associated with historical industrial use. The fill material generally comprised of loose and very loose sands, with isolated pockets of cohesive materials, peats, pulped paper and general construction waste. In addition, during construction, underground storage tanks were identified at depth, indicating the historical extent of filling across the site was extensive. The presence of this generally uncontrolled fill was a factor for determining that the most cost effective foundation solution for the paper mill was piled foundations, to bypass these materials."

Jan 1, 1900

By George Gazetas, Sissy Nikolaou, Fani Gelagoti, Irene Georgiou, Rallis Kourkoulis

"The need to shift geotechnical design from a “factor of safety” to a “performance based” design (PBD) approach has increased rapidly in the past years following examples from structural engineering. PBD supports sustainable engineered systems that target project-specific geotechnical behavior objectives and results in more rational and, in most cases, less conservative solutions. Resiliency, efficiency, risk optimization, and cost-effectiveness are key components of this approach. For design of retaining walls, the concept of mechanically stabilized earth (MSE) systems combines these attributes, while being environmentally friendly and adaptive to variable construction conditions. Natural hazards, such as earthquakes, may drive the design of MSE systems whose reliability depends on their performance under extreme events. In this paper, the authors compare the seismic response of an MSE steel-reinforced vs. concrete-reinforced retaining wall. The MSE system is composed of a grid of longitudinal and transverse ribs which internally enhances the capacity of the soil backfill. Results of fully non-linear twodimensional (2-D) numerical finite element analyses using two commercial programs with emphasis on the interface conditions are presented. The pull-out resistance of the grid used in the numerical simulation was evaluated from actual pull-out experiments. The results demonstrate a superior performance of the MSE system as compared to the concrete one, especially when subjected to strong seismic excitations.INTRODUCTIONThe idea of performance-based geotechnical engineering is not new, and has been evolving as our perception for ‘good’ performance has also evolved (Kramer, 2008). In early practice, the only criterion for achieving good performance was to avoid failure; designers had only to ensure that the available capacity of the geotechnical system is sufficiently higher than the expected demand (i.e. Load and Resistance Factor Methodologies). Yet, even when the key design requirements against collapse are satisfied, the system may still be placed into a condition in which the deformation constraints are not met (Bolton, 2012). To address these issues, geotechnical design has been developing into a predominantly performance-based approach that correlates deformation considerations to the severity of the experienced loading. As such, in earthquake-related problems, the definition of good performance of a geotechnical system is no more unique; for a low intensity earthquake the system should remain serviceable (i.e., the developed deformations should remain low), whilst for the design earthquake the maintenance of lifesafety is the single performance criterion."

Jan 1, 2016

By Thai Nguyen Ph. D

Dynamic Load Test (DLT) on driven piles has been performed routinely all over the world. In several recent projects, even 100% testing has become a norm where every single pile is dynamically load tested. In these cases, most piles are of uniform sections, making the field analysis (CASE method) straight forward. The CASE method, which has been used for the last 50 years, however, is only applicable to uniform piles to monitor pile driving stresses as well as pile capacities. Signal matching analysis can handle different configurations. However, the analysis used to require user inputs (i.e., non-automatic). Manual signal matching analysis, which can solve non-uniform solutions, traditionally takes hour(s) to complete for one blow. As such, the real-time pile driving stresses and resistances had traditionally been relying upon the CASE method, using typical range of CASE damping (JC). Until 2021, due to the lack of a rigorous instant signal matching analysis for non-uniform piles, no tool was available to help engineers evaluate non-uniform piles in real-time. An inexperienced field engineer may overlook this shortcoming when evaluating peak driving stresses. Furthermore, ultimate bearing resistances for non-uniform piles may require further evaluation to account for the non-uniformity of piles if relying on the CASE method. This paper highlights recent advances in instant Signal Matching Analysis on non-uniform piles, allowing field engineers to monitor stresses and resistances of non-uniform piles during driving.

Oct 1, 2022

By Emre Biringen

"Results from a small-scale laboratory experimental program show the changes in the vertical stiffness and strength of a soft clayey soil adjacent to the shaft of an inserted pile (i.e. expansion of a cylindrical cavity). The experimental program provides a realistic axi-symmetric physical model of an element of a cylindrical pile and the surrounding soil. The study interprets the improvement and assesses its magnitude in vertical stress-strain-strength properties of a normally consolidated soft cohesive soil in response to preloading impact in the radial direction. The results verify that insertion of a cylindrical pile causes densification of surrounding soil in a radial direction due to change in stress state around the pile, and thus consolidating and stiffening of the soil.The test results indicate that most improvement in modulus and strength takes place within a distance of 4 times the radius of a pile, though significant improvement is realized to a distance of 8-10 times the radius, beyond where there is negligible effect. Settlement characteristics of the surrounding soil in a zone of 12 times the pile radius improve significantly after the formation of a cylindrical cavity. The miniature vane shear strength tests show a 1.5 times increase in a zone of 4 times the pile radius compared to the strength at 10 pile radii. The results also imply that the spacing of cylindrical piles should not be more than 4 to 10 times pile radius, so that the surrounding soil matrix may improve the vertical bearing capacity under any foundation or embankment loading.INTRODUCTIONThe engineering community is familiar with different techniques to improve the bearing capacity and settlement characteristics of weak cohesive and organic soils. Some of the in situ techniques to improve the properties of soft ground (e.g. soft clays) prior to placement of foundations are vertical preloading, deep cemenUlime mixing, stone columns, and grouting (Henn 1996; Moseley 1993). In addition to these methods, researchers have recently showed interest in achieving soft ground improvement by means of applying radial compression method for which different names exist including expanding pile (Kelleher et al. 2001 ), Preload™ Pier (Biringen and Edil 2003), and sand compaction pile (Lee et al. 2004). Handy (2001) has described how preloading can also be achieved by imposition of radial loading in soft ground with an expected improvement in stiffness. The idea behind the latter method is densification and consolidation of soft soil in the radial direction by controlled displacement for which the process can be viewed as a cavity expansion problem (Vesic 1972)."

Jan 1, 2005

By Allen Cadden

The type of soil we had was a silty fine sand. It had been placed by hydraulic methods in 1904 so it was quite clean I would say less than 10% silt the rest of it was very loose sand. That I'm not certain, I've only done it on sandy soils but it would stand to reason that some sort of a number should apply because you are measuring the amount of work that you are doing to it so if the soil is fairly consistent over the site it should be able to generalize from there but I don't know for a fact that it works. Well, verifying to ourselves that this method actually worked because we weren't certain at first when we were doing it so then we would develop the numbers and then check the results.

Feb 10, 2003

By James Coull, Brian Wilson, David Siddle

"In 2012, Golder Construction Inc. was awarded a Design-Build contract for the design and construction of an extensive, deep ground improvement scheme to support up to 20 metres (66 ft) high Mechanically Stabilized Earth walls and bulk earthworks required for the development of the proposed Kitimat Liquefied Natural Gas (LNG) facility at Bish Cove, British Columbia (BC). Utilizing Cutter Soil Mixing (CSM) to construct barrettes consisting of overlapping rectangular panels of in-situ cement-treated soils, a deep mixing scheme, covering an area of approximately 12,900 m2 (15,430 yd2) and comprising some 1645 CSM panels to depths of up to 30.7 m (101 ft), was developed to provide the required static and seismic stability for the LNG structures, and meet the project-specific performance criteria.CSM panels were constructed through varying thicknesses and discontinuous layers of fine-grained, very soft to soft marine deposits, and loose to compact sands, with occasional interbeds of dense sands and gravels. Panel completion criteria was based on soil response factors, as measured by the CSM equipment, with the design requiring a typical embedment of about 2 m (7 ft) into dense silty sand to sand and gravel to provide the required bearing. A total volume of approximately 73,900 m3 (96,660 yd3) of soil was treated with cement to consistently yield average unconfined compressive strengths exceeding 2.5 MPa (363 psi).This paper outlines the challenges associated with the construction and quality control of this large deep mixing scheme in highly variable geotechnical conditions at a remote location with barge-only access, and limited communication facilities. Specifically the paper will discuss the logistical challenges faced and solutions adopted for the project; equipment redundancy requirements for a 24/7 operation; the impacts of wear and tear, as well as variability in subsurface conditions on productivity; quality control processes adopted for the project, including the value of provision of an on-site laboratory; and materials handling issues, and their impacts on mix design and quality control."

Jan 1, 2017

By Jørn Thomsen, Christoffer Brodbaek

"As governments increasingly accord high priority to sustainable energy, policymakers are finding that wind energy has a long track record as a proven alternative to conventional energy supply.Over the past two decades, wind turbine projects have been constructed offshore because of more stable offshore wind conditions and because there is more available space for large wind farms out in the open sea. Vindeby Wind Farm in southern Denmark was constructed in 1991. As the world’s first offshore wind farm, it provided valuable information and experience for researchers and designers that have led to new technologies and design improvements, a trend that will continue as more offshore wind farms are constructed. Today, the world’s capacity of the installed offshore wind turbines exceeds 1,000 MW. Most of these are installed in Northern Europe where there was early political support and favorable conditions, such as strong winds and relatively shallow waters. Offshore wind projects are now under development around the globe, including continental Europe, the U.K. and North America. ‘The largest offshore wind farm today is Denmark’s Nysted Offshore Wind Farm, which has a total capacity of approximately 480,000 MWh, equivalent to the yearly consumption of 120,000 households. It is five to six miles offshore in the Baltic Sea in the southern part of Denmark.The owner is a joint venture between DONG Energy of Denmark and E.ON Sweden. Bonus Energy (now Siemens) supplied the wind turbines, and P. Aarsleff A/S and subcontractors supplied the foundations. The contractor’s consultant, COWI A/S of Denmark, developed and designed the turbine foundations. With a total capacity of 165.6 MW, the project consists of 72 Bonus 2.3 MW turbines in water depths up to 33 ft. The turbines have a hub height of 226 ft, and the turbine blade diameter is 270 ft. The rotor and nacelle (the structure that houses the generator, gearbox and other equipment) weigh approximately 150 tons, and the weight of the steel tower is approximately 130 tons. The wind farm site is located in a relatively protected area of the Baltic Sea, but during the winter months, the water often freezes and the foundations needed to be constructed to resist ice forces. The founding soils at the site are overconsolidated clay tills with boulders and with a thin layer of softer surface sediments. Pockets of up to 30 ft of soft sediments were encountered, which required special foundation preparations."

Jan 1, 2009

By Arash Khosravifar

One of our research thrusts at Portland State University (PSU) centers on developing design guidelines for pile foundations in liquefiable, laterally spreading grounds. This research has been primarily sponsored by the DFI Committee Project Fund (CPF) program through four awards, totaling nearly $240,000 in financial support. DFI contributed half of this financial support, while the other half was contributed in-kind by PSU and DFI Project Advisory Board members. Leveraging the CPF funds, we secured an additional $550,000 in financial support from the National Science. Foundation (NSF), which has enabled our research group to continue exploring this topic and contributing to the broader engineering community's understanding of the behavior of pile foundations in liquefiable soils. The CPF funds have fostered collaborations with practitioners and researchers beyond PSU. Notable examples include collaborative research involving data from five large-scale centrifuge tests on pile-supported wharves by Steve Dickenson, Ph.D., New Albion Geotechnical; Nason McCullough, Ph.D., Jacobs Engineering and Scott Schlechter, Geotechnical Resources, as well as 1-g shake table tests of bridge pile shafts conducted by Professors Ahmed Elgamal, Ph.D., and Ahmed Ebeido, Ph.D., of the University of California, San Diego. In addition to these collaborations, our research has benefited from industry-university partnerships formed through the involvement of DFI Project Advisory Board members. Their support and feedback ensure that our research products are practical and imple- mentable in real-world projects. The impact of the CPF funds extends to supporting graduate students' theses, which were the basis for 17 technical publications. Some of these publications are expected to have a significant impact on the industry. For instance, our 2018 DFI Journal paper, co-authored by former master's student Jonathan Nasr, cur- rently with the Army Corps of Engineers, has been cited in the 2022 British Columbia Supplement to Canadian Highway Bridge Design Code S6:19. A noteworthy product of our study is a step-by-step design procedure for pile- supported wharf structures subjected to the combined effects of lateral spreading and inertial loads, outlined in a 2022 American Society of Civil Engineers' (ASCE) Journal of Geotechnical and Geo- environmental Engineering paper co- authored by former doctoral student Milad Souri, Ph.D., PE, Geotechnical Resources.

Nov 1, 2023

By Steffen Schweizer, Tadeusz Brzozowski, Alfred Koller, Michał Topolnicki, Jürgen Wäger, Grzegorz Sołtys

A full scale test has been conducted to determine ground bearing pressure under rig tracks. The track loads were recorded in real time using Liebherr's Ground Pressure Visualisation system, and the vertical stress induced in the ground was measured with pressure cells embedded in the ground. It has been found that the recommendation of EN 16228 regarding determination of the track length is oversimplified. The contact length should dependent on the susceptibility of the working platform. It has been also demonstrated that the corrected pressure distributions under the tracks influence the dimensioning of the working platforms. As a result, the designed working platform may actually be less secure than is shown by conventional calculations.

May 1, 2022

By Minna Karstunen, Patrick Becker

"Abstract The deformation behaviour of a foundation on deep mixed columns in a natural soft soil is a three-dimensional problem, which has to be considered adequately in numerical modelling. However, simplifications are often made due to the computational costs of fully coupled 3D analyses by either modifying geometry of the problem or material parameters in 2D for plain strain analyses or by modelling the problem as 2D axisymmetric case. The volume averaging technique (VAT) is an enhanced 2D FE technique that enables mapping the 3D problem in two-dimensions, yet modelling the two constituents (column and soft soil) with appropriate different constitutive models within a homogenized material. The performance of the volume averaging technique is demonstrated by considering unit cell simulations of floating and end bearing columns in soft soil. The results with VAT are compared and validated against conventional 2D axisymmetric and fully coupled 3D finite element analyses.IntroductionThe properties of very soft clays, silts and organic soils can be improved by stabilizing agents, such as lime and/or cement that are mixed into the soil in situ by using auger-type mixing tools in situ. Deep mixed columns are extensively used to reduce deformations and to improve the overall stability of embankments and foundations on soft soils. Whilst the most typical applications are embankments, increasingly the method is used under foundations. The first category of applications is very common in Scandinavian countries, whilst the latter application has been pioneered in Poland, as an environmentally friendly (low CO2) and cost effective alternative for piling. Due to economic and environmental reasons there is an increasing interest in the technique elsewhere in Europe. With deep mixing, the strength and deformation properties of the soft soil can be improved, and the risk of unwanted deformations is substantially reduced.Numerical methods, such as finite element (FE) analysis, can be used as an alternative to conventional design methods. They are particularly suitable when considering serviceability limit state, i.e. deformation analyses under working loads. FE analyses allow using advanced constitutive models that take account of the complex stress-strain behaviour of natural soil and stabilized columns, respectively. The problems that involve a grid of circular columns under an embankment or a strip footing are fully three-dimensional problems. As 3D analyses are very laborious and expensive, an enhanced 2D technique using the so-called volume averaging technique (VAT) is utilised. The basic idea is to describe the column-improved ground as a homogenized composite material, and using clever mathematics to map the true 3D problem into 2D. Once the constitutive relations of both composites are defined, the response of the column-improved ground can be simulated in 2D subject to arbitrary loading and boundary conditions."

Jan 1, 2014

By Ke Yang, Robert Liang

"Drilled shaft foundations are widely used for many types of structures, especially for highway bridges, high rise buildings, and costal structures. The lateral design considerations are crucial for those structures that are subjected to lateral thrust forces, winds, waves, and earthquakes. The p-y analysis is the most widely used method for the analysis and design of drilled shafts for lateral load applications in soils. However, existing p-y criteria were developed based on the lateral load tests on small diameter drilled shafts in soils. Although, a lot of lateral load tests have been conducted, there are a limited number of lateral load tests on large diameter drilled shafts embedded in clay. In this paper, a lateral load test on 2.44 m diameter fully instrumented drilled shafts in clay is presented. The site specific p-y curves are derived based on strain gage readings. The existing p-y curves are found to be much softer than the site specific p-y curves. Correspondingly, the deflection at the top of the test shaft under the maximum applied load is predicted to be eight times larger than the measured value using existing p-y criteria. A new p-y criterion is proposed in this paper. The proposed p-y criterion is proven to be able to capture the site specific p-y curves of the load test and to predict closely the deflections at the top of the test shaft. INTRODUCTIONDrilled shaft foundations are widely used for many types of structures, especially for highway bridges and costal structures. The lateral design considerations are crucial for those structures that are subjected to lateral thrust forces, winds, waves, and earthquakes. Although efforts have been made on studying lateral response of drilled shafts; nevertheless, only limited studies have been published on the behavior of large diameter drilled shafts under lateral loads and the corresponding design methods."

Jan 1, 2005

By Carlos Lam, Joram M. Amir, Erez I. Amir

"Abstract The modulus of elasticity of pile material (E) is an important parameter for the interpretation of both static and dynamic loading tests on piles. This value is commonly assumed to be constant with depth though it may not be true for deep bored piles due to the chosen casting method and/or selfweight consolidation. To provide evidence to support this proposition, the results of compressive strength tests on core samples taken from four different studies have been presented. The results show a marked increase in the strength and stiffness values with depth. The results of crosshole ultrasonic tests conducted at another site also confirm the same pattern. It is therefore recommended that before load testing a pile the distribution of the E values along the pile axis should be investigated. This will ensure the use of a realistic elastic modulus value and hence the correct interpretation of thedistribution between the shaft and end resistances.IntroductionThe modulus of elasticity of pile material (E) is an important parameter for the interpretation of both static and dynamic load tests on piles. Multiplying E by the strain measured by either strain gauges (e.g. ASTM D4945) or tell-tales (e.g. Geffen and Amir, 1971) gives the stresses acting at a given pile section. Typically, in the absence of better information, the value of E is derived from laboratory tests on concrete cubes or cylinder specimens taken on site and is assumed to be constant along the pile. While this may be correct for pre-fabricated concrete piles that are cast in horizontal molds, it may not be true for cast-in-place piles that are produced in the vertical position.There are at least two factors that may contribute to the change in concrete properties with depth in a bored pile. First, the casting methods may be by free fall in dry holes (e.g. Kiefer and Baker, 1994) or by using a tremie tube if support fluids are used. In the former case, the earlier batches reach the bottom of the pile bore at a higher velocity and are thus compacted under higher energy. Second, regardless of the casting method, the fresh concrete in the pile bore will always consolidate at least partially under its own self weight. The materials in the lower parts of the pile will therefore experience a higher consolidating pressure. This can reduce the pore volume and the water content in the wet concrete, thus changing the properties of the hardened concrete. Recent research by Justs et al. (2011) has shown that even a relatively small pressure can have a significant positive effect on concrete properties such as compressive strength and stiffness. However, the possible change of concrete properties with depth is commonly ignored by foundation engineers in the current design practice."

Jan 1, 2014

By Bernard B. Vannoy, Howard W. Gault, Ramesh Bobba

"Treviicos-Soletanche Joint Venture (JV) and the US Army Corps of Engineers (USACE) have installed a 3800-foot long, 275-foot deep and minimum 2-foot wide secant pile barrier wall at Wolf Creek Dam in Jamestown, KY. This paper describes the methodology employed by the JV and USACE to evaluate the overlap, thickness, and position of the barrier wall. It addresses the contractual requirements, positional uncertainty, and evaluation procedures.These procedures evolved over the course of the project as various issues were identified and procedures developed to evaluate these issues. During the project, it became clear that the JV and USACE could ascertain that the wall thickness and overlap requirements could be met if the overlap based upon Koden data was at least 0.7’ in the left-right direction. For a small number of piles with overlaps between 0.5’ and 0.7’, the piles are contractually compliant yet contain a minor degree of uncertainty in the overlap. Initially, the USACE assumption was that the amount of uncertainty of verticality measurements would require more than a 1-foot measured overlap in the left-right direction to confirm an actual, contractual 6-inch overlap. With time and experience, the limit of measured overlap was reduced in accordance with greater understanding of the equipment capabilities and tolerances. Other lessons learned include the need for Quality Control/Assurance personnel to collect data at the same starting point for every pile.For every pile the JV and USACE compared analog and digital data to provide confidence that the correct digital data was used for overlap calculations. Perhaps the most important lesson learned was the importance of the JV and USACE working together and sharing all data. Overlap analysis was performed by the JV’s Barrier Wall Specialist and a small number of USACE personnel. This resulted in a high level of experience and expertise within a small group.IntroductionThe Treviicos-Soletanche Joint Venture (JV) and the US Army Corps of Engineers (USACE) have installed a 3800-foot long, 275-foot deep, and minimum 2-foot wide secant pile barrier wall at Wolf Creek Dam in Jamestown, KY. The wall was installed through a 6-foot wide Protective Concrete Embankment Wall (PCEW) which was installed two feet into rock. The PCEW protects the embankment from erosion of drilling fluids during subsequent operations. Below the PCEW the piles were installed to a specified elevation (staggered at 475’ and 473’ below the 748.2’ work platform). The Ordovician limestone and shale bedrock is flat lying with few vertical fractures. These conditions facilitate the advancement of pilot holes with very low deviations (with considerable credit to the JV’s drillers and steering engineers). The pilot holes were spaced on 31.5-inch and 35-inch spacing. Subsequent enlargement of the pilot holes to 50’ resulted in a continuous wall. This paper addresses the requirements and procedures to assure that the wall was as wide, deep and continuous as specified."

Jan 1, 2015

By Tim Siegel, III Fondren, Billy Camp

"INTRODUCTIONThe new $650 million power block at Santee Cooper’s Cross Generating Station in Cross, South Carolina is being constructed on driven pre-stressed concrete (PSC) piles. S&ME, as geotechnical subconsultant to Parsons Energy and Chemical Group, was responsible for pile analysis and design to meet the site’s geotechnical and seismic challenges. Selection, analysis and design of the PSC piles included consideration of the following:• Column and equipment support loads ranging up to 500 to 1000 kips (2224 to 4448 kN).• Incorporation of the 2000 International Building Code seismic provisions.• A thick upper soft clay and loose, liquefiable sand.• Potential for karst-related features in the calcareous Santee Limestone.GEOTECHNICAL CHARACTERIZATIONThe near-surface site geology consists of (in order of increasing depth): (1) Pleistocene sediments, (2) the Santee Limestone (considered part of the Orangeburg Group) of Eocene age, and (3) the Black Mingo Formation of the Eocene/Paleocene age (refer to the shear-wave profile in Figure 4). Pleistocene clays and silts are generally soft and will settle significantly if subjected to loading by heavy grade-supported structures while the interbedded sands are generally loose. Where submerged below the shallow groundwater table, the sands were determined to be liquefiable during a strong earthquake.The Santee Limestone is a nearly white to yellow fossiliferous and partly glauconitic rock consisting chiefly of calcium carbonate. Observations of the rock core samples from the site indicate that it can range from hard crystalline limestone (primarily in thin layers) to a lightly cemented sand. In terms of rock strength, the Santee Limestone is generally very soft to soft, depending on the cementation and other depositional characteristics."

Jan 1, 2004

By M. D. Riegel, P. B. Pizzimenti, E. M. Zamiskie, Britain A. Materek

"The Skanska/Kiewit/ECCO III team (SKE) in association with HNTB was awarded the design-build contract for Phase I of the Kosciuszko Bridge Replacement Project. As lead designer for the SKE team, HNTB was responsible for the design of the Brooklyn Connector which includes construction of approximately 2000 feet of new staged earth-filled embankments utilizing prefabricated modular retaining walls (T-Walls®). The proposed embankments will be constructed adjacent to and beneath the existing Brooklyn Queens Expressway (BQE) viaduct while the existing viaduct remains in service. Critical aspects of the settlement assessment relating to the soils supporting the existing BQE will be addressed, as their behavior drives the deformation of the viaduct. Furthermore, a construction monitoring program was used to enable the designer to assess settlement predictions and allow SKE to mitigate potential impacts to the existing BQE during construction. Additionally, the methodology for installation of the embankments in a limited access area underneath an active viaduct supported on settlement sensitive shallow foundations will be presented.INTRODUCTIONSkanska-Kiewit-ECCO III Joint Venture, in association with HNTB was contracted by the New York State Department of Transportation (NYSDOT) to design and construct the Phase 1 replacement of the Kosciuszko Bridge Design-Build Project. Phase 1 of the project involves the design and construction of the new eastbound structures of Interstate 278 over Newtown Creek from Brooklyn to Queens. The project runs between Morgan Avenue in Brooklyn and the Long Island Expressway Interchange in Queens (approx. 1.1 miles) and includes the staged demolition of the existing structures."

Jan 1, 2016

By Athena C. Denivo, Pablo V. Lopez, Michael McMaster, Sissy Nikolaou, Alfred H. Brand

"The paper presents the history of development of the United States Tennis Association (USTA) site, focusing on geotechnical, geoseismic, and foundation engineering challenges associated with it. The site is located at the Flushing Meadows Corona Park area of Queens, New York. Now home to the Billie Jean King National Tennis Center (BJKNTC), the site used to be a biologically rich, tidal salt marsh that extended south from Flushing Bay and overlaid an ancient buried valley. In early 20th century, Brooklyn Ash Co. was contracted to fill the marshland with cinders and furnace ashes. F. Scott Fitzgerald describes the “Valley of Ashes” as “a fantastic farm where ashes grow like wheat into ridges and hills and grotesque gardens; where ashes take the forms of houses and chimneys and rising smoke, and finally, with a transcendent effort, of ash-gray men who move dimly and already crumbling through the powdery air.” In 1939 the site was leveled and filled to host the World’s Fair and refilled again for the 1964 World’s Fair.The USTA moved to the site in 1978 and in mid-1990’s constructed the 23,000-seat Arthur Ashe Stadium (AAS). Currently, USTA has a Strategic Vision Plan venue with several interconnected construction projects including buildings, infrastructure upgrades and improvements to site circulation. In addition to a historical walkthrough, the authors will discuss technical challenges of supporting these developments through layers of fill, thick organic silty plastic clays and regional varved soils with bedrock found 300 to 400 feet deep. The subsurface is not only a weak foundation medium, but is susceptible to large amplification of seismic waves propagating from the bedrock during earthquakes. The developments are usually founded on project-specific pile foundations that carry static loads in deeper layers and accommodate lateral demands and performance objectives. Engineering innovations from the most recent development, the roof structure over AAS, will be discussed."

Jan 1, 2016

By Ronaldo Luna, Donald Deardorff

"The use of load and resistance factor design (LRFD) is well documented since the 1960s for structural applications when it was first adopted into the American Concrete Institute Building Code in 1963 and was established for geotechnical applications by the Danish Geotechnical Institute about the same time under the name of Limit State Design (LSD).The Federal Highway Administration required all federally funded projects to use the LRFD method by 2007. Due to this funding requirement, recent LRFD research for geotechnical applications has focused on common bridge foundations (i.e., driven or drilled shafts), resulting in good documentation for design using these methods. Unfortunately, the practicing geotechnical engineer does not intuitively know how to create resistance factors for deep foundations systems that have design methodologies and installation techniques significantly different from driven or drilled shaft foundation systems.Helical anchors typically use semiempirical methods for preliminary capacity design and a torque correlation methodology during installation to verify required capacity. Here we provide basic information on the LRFD methodology for helical anchor design. Additionally, the First- Order Second Moment (FOSM) method is applied to a previous helical anchor study (Hoyt and Clemence 1989) to determine resistance factors for an ultimate tension capacity strength limit state.MethodologyThe concept of the LRFD method is to establish factors for both the load and resistance that account for uncertainties using probability theory. The factors increase the nominal load and/or decrease the nominal resistance such that the probability of failure is an acceptable value. LRFD also accounts for the effects of load combinations (dead, live, seismic, wind, etc.) by determining the probability of the combined occurrence. The general form of the LRFD equation used by American Association of State Highway and Transportation Officials (AASHTO) is:"

Jan 1, 2009

By Brad W. Taylor

"During the past several months, I have introduced to civil and structural engineers an innovative solution for the integrity testing of concrete using the Thermal Integrity Profiler (TIP) Wire Cable System by Pile Dynamics. While in the process of “educating” highly-trained professionals about a technological breakthrough, I ended up being educated myself about their needs for quality control/quality assurance (QA/QC). With that in mind, I would like to focus on their two key areas of concern:• How complex is the TIP installation process?• How does the QA/QC engineereffectively analyze and report TIP test results?A few months ago, during a discussion with a senior QA engineer, he asked a question that stopped me in my tracks: “Why should we do foundation testing at all?” Turning it around, I asked, “Why wouldn’t QA/QC personnel want to know everything they could about their critical infrastructure foundation?” Honestly, I didn’t answer his question nor did I fully comprehend what he was trying to say. With his experience, the engineer understood that there has not been an integrity test or a combination of integrity tests that could deliver an inside the cage and outside the cage (cover) complete data set that would provide a definitive profile of the entire shaft. Crosshole sonic logging (CSL) becomes more effective the larger the diameter of the shaft becomes, with a maximum effectiveness between 70% and 80%, but does not provide any data of the integrity of the shaft beyond a straight line between CSL tubes. Gamma-gamma logging (GGL) provides qualitative information about the concrete surrounding the GGL tube and device, and it provides information about a small percentage of the drilled shaft concrete near its outside edge."

Jan 1, 2017