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By Brendan Stepek, Michael Senior, Gary Brill

Freight railroads are classified as critical infrastructure and are an important piece of the U.S. economy. Railroad tracks cover the entire nation, allowing freight trains to transport goods and materials between ports and other transportation hubs. We have shaped the landscape to construct America's vast network of railroads; we have flattened mountains, carved into hillsides, filled valleys and spanned gorges. As natural geotechnical hazards occur at railroad sites, it is critical to remediate the hazard in a timely and minimally disruptive manner to main­tain operations. Norfolk Southern Railway has mainline rail passing through the foothills of the Blue Ridge Mountains of Central Virginia that services about 15 to 20 trains per day. Along this rail is a 70 ft (21 m) high cross valley embankment fill that has experienced a long history of instability and numerous attempted repairs. In 2020, after a noticeable increase in rail movement, Norfolk Southern elected to have a compre­hensive geotechnical study of the embankment performed, install instru­mentation and ultimately stabilize the soil slope. The instrumentation and design of the slope stabilization system was performed by Schnabel in 2021 and was constructed by Goettle in 2022.

May 1, 2024

By Aneesh Goly

In the dynamic landscape of foun­dation engineering, where precision and reliability are paramount, recent technological advancements have heralded a new era of sophistication and efficiency. At the core of this transformation is the integration of artificial intelligence (AI), the Internet of Things (IoT) and embedded data collectors (EDCs), each playing a pivotal role in redefining traditional practices. The current state of foundation en­gineering is one characterized by a heightened emphasis on data-driven decision-making, predictive analysis and enhanced safety protocols - all underpinned by these technological innovations. The impact of AI, IoT and EDCs on foundation engineering is profound. AI algorithms, with their capacity for processing vast amounts of data, offer unprecedented insights into soil be­havior and structural integrity. loT brings a new dimension of connectivity, enabling real-time monitoring and communication between various components of a construction project. EDCs, integral to this network, provide the crucial data that fuels both AI analyses and IoT efficiency. Together, these technologies are not just add-ons but have become fundamental to the field's advancement. This article aims to delve into the synergy of AI, IoT and EDCs within foundation engineering, exploring how their integration is shaping the future of the industry. We will trace the evolution of foundation practices from their traditional roots to their current state­of-the-art incarnations, highlighting how these technologies are driving the field towards more efficient, safe and sustainable practices.

Apr 1, 2024

By Shawn Downey

A short section of 230 kV transmission line was built with four 95 ft (29 m) steel monopoles to connect a solar farm to a substation through an environmen­tally sensitive wetland in the south­eastern U.S. The foundation required to support a monopole is primarily a moment resist­ing foundation, supporting an eccentric lateral load that creates an overturning moment at the base. The moment cre­ated tends to be quite large, which often results in a large and expensive founda­tion. In this case, there were two differ­ent load conditions to support. The first load condition, a 1,612 ft kip (2,185 kNm) moment combined with 16.4 kip (73 kN) axial compression and 21.7 kip (97 kN) shear, was supported by a 12 pile above ground steel grillage. The second load condition, a 1,323 ft kip (1,794 kNm) mo­ment, 14.8 kip (66 kN) axial compression and 20.0 kip (89 kN) shear, was support­ed by an eight pile above ground grillage. Typical deep foundation choices for these types of loads would include: Large diameter drilled shaft replacement foundation, soil is removed and replaced with concrete. Dr iven piles - displa cement foundation with a concrete pile-cap at the surface to tie the piles together. Micropiles - replacement founda­tion consisting of small diameter, drilled and grout-reinforced piles tied together at the surface with either a concrete cap or a steel grillage. Helical piles - displacement foundation with an innovative steel grillage system made from mostly recycled steel to tie piles together at the surface

Apr 1, 2024

By Clint Judisch, Ty Jahn

Nestled at the apex of Big Sky Resort's Lone Mountain, in Big Sky Montana, (3,400 m), making it the highest scenic overlook in the state. Boasting breathtaking views that span over 20 different mountain ranges, this engineering marvel replaces the original tram after a 28-year run that exceeded the original design life. The new tram consists of a top and bottom terminal, as well as a singular support tower that sits about three quarters of the way up the span. The project team consisted of Condon-Johnson & Associates as the general contractor who self-performed the construction of the foundations for the top terminal and tower, involving intricate processes such as blasting, excavation, drilling, installation of micropiles and tiebacks, and concrete. Doppelmayr manufactured and supplied the tram car plus components. Garaventa designed and erected the metal tram structure, built the ropeway and tram stations.

Apr 1, 2024

By Tina Hastings, Karen Dawson, Ryan Dunne, Patricia Bennett

The Georgetown Wet Weather Treatment Station is located in Seattle and will treat up to 70 million gal {265 L) per day of combined sewage that would have otherwise discharged directly to the Lower Duwamish Waterway without treatment during storms. The facilities also include conveyance of raw combined sewage from existing large­diameter pipes to the treatment station and of treated effluent from the treatment station to the new outfall structure located in the Lower Duwamish Waterway. The most geotechnically significant structures at the treatment station are a large process building (approximately 220 x 110 ft [67 x 34 ml) that houses mostly above-grade ballasted sedimentation, solids storage and ultra-violet disinfection, and a below-grade, nominal 100 ft (30 m) diameter influent pumping station/equalization basin (IPS/EQ) constructed within a 92 ft (28 m) deep secant pile ring. The station also includes additional support buildings, vaults, above-grade rainwater harvesting cisterns and large-diameter pipelines. This article specifically outlines key geotechnical decisions for design and construction of the process building and IPS/EQ at the treatment plant site and presents case history information from construction of the IPS/EQ. The key geotechnical challenges faced during design included: A site with more than 120 years of industrial use, occupied by operating businesses; this resulted in limited access for subsurface explorations, soil and groundwater contam­ination, potential obstructions/undocumented utilities, restrictions on hauling and street closures, and existing structures within feet of the property lines. Compressible soils also subject to seismic liquefaction. Tight grade tolerances for weirs, large pipe connections and some equipment that reduced the amount of allowable settlement. A schedule with immovable milestones dictated by consent decree. A companion paper titled "Instrumented Load Testing and Construction Monitoring of Rigid Inclusions in Seattle" was presented at the DFI 48th Annual Conference on Deep Founda­tions and delves into the technical details of the unreinforced rigid inclusion ground improvement system that supports the process building.

Mar 1, 2024

By Albert Allaart, Rodriaan Spruit, Hans Pacejka, Suzanne J. M. van Eekelen

The Sint Sebastiaansbrug (Saint Sebas­tian Bridge) in Delft, the Netherlands, was built in 1964. The bridge crosses the Delftse Schie, or waterway, with a fixed span of 12 m (39 ft} and a movable span of 12 m (39 ft). In the middle of the waterway, both the fixed and movable bridge decks rest on a pier. The vertical clearance of the fixed part is 4.5 m (15 ft}. On both banks there is an ap­proximately 80 m (262 ft) long access ramp, consisting of a concrete con­struction on piles. Each section of the access ramp has a span between supporting structures of approximately 10 m(33 ft}. During the preparations for con­verting the bridge to accommodate a tram in 2006, a thorough inspection of the bridge was executed. The inspection conclusions were very unfavourable. Several supporting structures had settled considerably, causing structural damage to the upper structure. Adding bearing capacity to the failed foundation, repairing the struc­tural damage and accommodating the tram on a wider bridge was studied in 2010 and was found unfeasible and the uncertainty profile associated with this solution was also considered to be too high.

Mar 1, 2024

By Renee Fippin

Several projects are underway in Nassau County, New York, to improve water quality in the Western Bays of Long Island. A major piece in accomp­lishing this is the Bay Park Conveyance Project. When completed, it will divert most of the treated effluent away from the Western Bays to an existing ocean outfall at the Cedar Creek Water Pol­lution Control Plant. The ongoing works include 3.6 mi (5.8 km) of micro­tunneling, 7 mi (11.3 km) of sliplining, 14 shafts and a 75 million gal (284 mil­lion L) per day pump station. In February 2021; Western Bays Constructors (WBC) - a joint venture of John P. Picone and Northeast Remsco Construction - was awarded the design-build contract. For final design, WBC retained Delve Underground to lead the design team for the project. Delve Underground worked in concert with WBC and its subcontractor, Keller, to determine optimal shaft construction methodologies, and during tender, evaluated options that would limit groundwater inflows to the allowable limits. This article focuses on how support of excavation {SOE) was selected for the 14 primary shafts for the microtunneling efforts as well as key design components to address shaft performance needs.

Feb 1, 2024

By Nick Benedetto, Sonia Sorabella Swift, Taylor Towle, Seth Pearlman, Andy Sullivan

The Route 1&9T/New Road project is a three-part program to relieve the notoriously congested Route 1&9 (Tonelle Avenue) in the heart of the industrial sector of Jersey City, New Jersey. Contract 1 consisted of con­structing a new road over a 1 mi (1.6 km) Long stretch of unimproved land serving as part of the parking lot to a large postal facility. To get to grade, modular gravity retaining walls were specified on either side of the 54 ft (16.5 m) wide roadway corridor. While the proposed wall heights ranged from only 2-8 ft (0.6-2.4 m), the soils present on-site were not even suitable for a shallow embankment. The underlying soils were mixed fills and organic peat, underlain by soft clay and silt to depths ofupto 75 ft (23 m). The proposed solution presented in the project plans certainly would have worked on paper; however, Menard, having had poor experiences with rigid inclusion installation and load transfer platform (LTP) compaction at or just above the groundwater table, recog­nized the potential difficulties, delays and rework that would likely be required during construction of what was shown on the contract plans. As such, it proposed a value-engineered solution that resulted in a vast improve­ment in the constructability, perfor­mance and overall cost of the system. However, the benefits of this solution were not appreciated by the owner and the solution was met with high levels of scrutiny, perhaps because it differed from what was shown on the contract plans. The level of testing required of the solution was far greater than what was required of the design shown on the contract plans. Such rigorous and unwarranted confirmation of a value­engineered solution consumed time, money and resources that could be better used elsewhere. Instead, these designs should be compared to the design in the original contract plans based on technical merit and expected long-term behavior. This article walks through the design and construction process for the value-engineered solu­tion and highlights the many challenges experienced by the contractor to get final approval of the work perormed. Though the COVID-19 Pandemic was an unanticipated complication, the per­ceived distrust of the contractor's proposals and work was a barrier to progress that the authors hope will not exist in the future.

Feb 1, 2024

By Brian Metcalfe, Kord Wissmann, Gianni Martinez

The Middle East consists of vast deserts that reach temperatures up to 50°C (122°F), with some areas characterized by endless sand dunes. When project team members selected the location for a large new transportation project, little did they know that the site would be characterized by soft, nearly normally consolidated silt and clay extending below a thin sand crust. Searching for solutions, the design team elected to reinforce the sub­surface with rammed aggregate pier ground improvement elements and wanted verification that the method would stand the test of prolonged static loads. Because the concrete pave­ments would serve to spread the load, a "zone load test" was performed, consisting of applying a uniform bearing pressure of 150 kPa (22 Psi) over a 7.5 m (25 ft) square concrete footing. Unlike individual pier load tests, the zone test allowed the project engineers the opportunity to confirm design parameter values under large­loading area conditions, a situation not often available to most designers. This paper presents the results of the zone load test, which may be interpreted to better understand design parameter values, and is of particular significance because it adds a valuable contribution to the relatively few numbers of "group load tests" available in the literature for ground im­provement applications.

Feb 1, 2024

By Eric Sturel, Ove Arup, Henry Tayler

One Triton Square was originally a six­storey commercial building with a single level basement located within the Regents Place development near Euston, London. The building was a concrete frame, with steel cores at each corner. The floorplate was approximately 72 x 72 m (236 x 236 ft) with a 36 m (118 ft} wide octagonal central atrium. The original building was well suited for extension due to relatively recent construction standards, high original live load allowances, its large central atrium, generous escape stairs provision and extensive record information. Plant space requirements at basement and rooflevel were maintained. The preferred scheme was the addition of three storeys to the existing six-storey structure and an eight-storey partial infill in the central atrium area, with a further allowance for completely filling in one or two of the lower atrium levels. This allowance was included in the design to offer enhanced flexibility to future tenants. It was clear from an early stage that the foundation load demand would increase to serve the enlarged building area, which increased the existing building floorplate by 70% or 130,000 sq ft (12,100 m2) of commercial space. Maintaining the basement headroom and accessibility for servicing plant would also be important.

Jan 1, 2024

By Alex Sherman, Gretchen Connelly

The Soo Locks, which date back to the 1800s, are the major cargo connection point between Lakes Superior and Huron. The locks allow the movement of approximately 86 million tons of freight annually through the Great Lakes, the St. Lawrence Seaway and the international markets. Considered a feat of engineering, the locks raise and lower boats to allow passage between the two Great Lakes using a series of gates and chambers that are powered solely by gravity, without the use of any pumps. The Soo Locks are currently made up of the Poe, MacArthur, Davis and Sabin locks. The Poe Lock, the most utilized of the four, was rebuilt in the 1960s to accommodate larger ships. Currently, approximately 90% of the commodities transported through the Soo Locks are restricted to the size of the Poe Lock. The MacArthur Lock, the southernmost lock, is also currently operational. Neither the Davis nor the Sabin Lock are currently in operation.

Jan 1, 2024

By Ross Cutts

As a public servant geotechnical engineer, I observed how costly and valuable geotechnical field explorations are to the success of every project. Often however, the field exploration is a long and complex process that is made less efficient by the difficulty of retrieving and utilizing nearby internal or external historic geotechnical datasets. As an employee of a public agency, we would often start our investigations for every project from scratch, given the difficulty of locating and utilizing historic geotechnical data. This is an ethical and technical failing of our profession. When we start subsurface explorations from scratch, not only do we often duplicate investigations, we are also likely defaulting to reapplying tradi- tional test methods that yield con- servative geotechnical parameters, resulting in overly conservative and potentially costly construction. To address this issue while working as a public servant, I started a research program with Yunfeng Zhang, Ph.D., of the University of Maryland, to build a tool that could compile internal historic geotechnical data and extract additional value from it, using machine learning. This tool was able to provide, upon request, nearby historic geotechnical data, estimated soil parameters and recommendations for geotechnical test methods best suited for a given project site. This prevented common field ex- ploration problems such as, requesting duplicate data, requesting test methods that were not applicable for the project geology, not realizing presence of karsts, missing permits for wetlands, private property and others. This tool allowed for more efficient field investigations with regards to time and money saved. There was one problem with this tool: it could only be used by internal employees of a single state's depart- ment of transportation (DOT) for which this data was compiled. I realized at that point that it would be of tremendous value to make this concept universally accessible to the geotechnical engi- neering profession. I left public service to devote time to building a platform that would host historic geotechnical data from publicly funded sources throughout the country. The tool I helped build as a public servant was the foundation of Geosetta, a nonprofit company dedicated to serving the geotechnical profession. The nonprofit structure was adopted to prevent acquisition by a for-profit company and to ensure that Geosetta remains an independent steward of our profession's valuable data. Geosetta provides a GIS (geographic information system) platform that enables users to view historic geo- technical data and extract value from it with machine learning-based predictions and visualization tools. This data is provided in an open and interchangeable format called DIGGS, which stands for Data Interchange for Geotechnical and Geoenvironmental Specialists, making it easy for users to integrate it into their workflows. Geosetta is collaborating with the American Society of Civil Engineers' Geo-Institute and other sponsors to extract public data at no cost to the agency and provide the profession with free access to the existing data and access to advanced tools through a subscription to support the nonprofit mission.

Nov 1, 2023

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 Anne Lemnitzer

Experimental data are the cornerstone of scientific research, providing empirical evidence to validate hypotheses, test theories, inform decision-making and help develop innovative design and analysis methods. However, beyond traditional empirical validations, experimental data have also become the most crucial component of AI algorithms, measuring the algorithms' effectiveness, and allowing engineers to ensure their reliability and applicability. The DFI "Rock Socket Project," awarded in the spring of 2018 allowed for the indispensable, experimental data-based validation of structural shear magnitudes, which have been hypothesized and discussed for years within the deep foundations community and cautiously approached by many design engineers. The fundamental project idea, i.e., the investi- gation of pile shear magnitudes through experimental research, was sparked during a heated discussion in the October 2016 Drilled Shaft Committee meeting in New York. Should we design for amplified shear at the rock socket of a drilled shaft or is this merely an artifact of the p-y design approach? Data were needed to provide consensus.

Nov 1, 2023

By Hannah Lezzoni, Morgan NeSmith

The Augered Cast-in-Place and Drilled Displacement Pile Committee has historically been one of the most active and engaged DFI committees and has performed or spearheaded a number of research projects via the DFI Committee Project Fund (CPF). The authors have had the privilege of being either past or current committee chairs and have been involved in the performance of most of these projects since the fund's inception. The following is a historical overview of the committee's projects and their outcomes.

Nov 1, 2023

By A. J. Metz, Roberto Nevarez

One popular method to stabilize slopes is the use of deep foundation elements to support lateral loads from an unstable soil or rock mass. Drilled deep foundation elements are often selected due to local availability of equipment, access concerns, cost considerations and post-construction aesthetics. Often, one or more rows of deep foundation elements are installed running parallel to the slope. The elements in each row may or may not be connected through a cap beam. They work primarily in bending, and resist slope movement by transferring the earth pressures down below the potential slip surface. Design of these systems considers the effect of arching

Nov 1, 2023

By Ramin Motamed, Reza Mohammadi, Zahra Faeli

Finite element methods can be used to analyze the dynamic responses of soil-foundation-structural systems during earthquakes. Therefore, the validation of finite element models with actual seismic recordings is required to benefit from their use in foundation seismic design. In this paper, the acceleration records from the Hayward-I580/238 bridge in California will be studied. At the HaywardI580/238 bridge, three-component accelerometer recordings from two geotechnical downhole arrays at the surface and depths down to 90 meters were used. Furthermore, from 2011 through 2022, 15 earthquakes were recorded at these downhole arrays ranging from Mw 3.4 to Mw 6. However, this paper focuses on the earthquake events within the range of Mw 3.4 to Mw 4.4. Therefore, this study is limited to earthquakes up to Mw 4.4. In the first part of this study, a free-field model of the Hayward-I580/238 bridge site is built using the OpenSees software. Then, in the second part, a drilled shaft of the HaywardI580/238 bridge is modeled. A comparison of the dynamic responses generated by OpenSees with the recorded data from the geotechnical downhole arrays will be used to validate the free-field model, and the acceleration responses from the free-field model will be applied to the drilled shaft. Then, the behavior of the drilled shaft under the applied seismic forces in terms of different calculated parameters (e.g., displacements, reaction forces, etc.) will be investigated. As a result of this study, despite the absence of actual acceleration recordings, obtaining the responses of the soil layers in various depths is possible using a numerical modeling method. In conclusion, not only OpenSees provides a tool for monitoring drilled shaft behavior during seismic events, it provides a robust tool for future drilled-shafts seismic designs.

Oct 31, 2023

By Taylor Stevenson, Takefumi Takuma, Andrew Rose, Chris DellAringa

The city of Huntington Beach is a coastal community along the Pacific Ocean in Southern California with a series of intracoastal flood channels that run through densely populated residential areas. The Huntington Beach Channel and Talbert Channel Sheet Pile Repair Project was designed to improve flood protection for surrounding Huntington Beach communities. The project consisted of installing over 16,000 linear feet of new steel sheet piles adjacent to existing steel sheet piles that line the sides of both flood control channels. This paper studies the unique project dynamics and constraints, and highlights the capabilities of the press-in piling method for sheet pile installation.

Oct 31, 2023

By Vijaya Rao Parigela, Jason Redgers

A 6m height approach ramp was proposed connecting the new railway line at ground level with the existing, elevated line and facilitating an intersection. The ramp mainly consists of a reinforced concrete box section with rising top elevation following the gradient of about 6 degrees for a total length of 120m. Based on the provided SLS loads, resistance was required for 75 kPa to 280 kPa loading pressures. Soil stabilization using Deep Soil Mixing, DSM technique was chosen as alternative to CFA piled foundations by the client to limit settlements. Generally, soil conditions consisted of a made ground layer comprising of granular and cohesive deposits underlain by boulder clay and the Pennine middle coal measures. The specifications for treatment were based on the Federal Highway Administration Design Manual: Deep Mixing for Embankment and Foundation Support and required improving the strength of the made ground below the reinforced concrete elements to an acceptable stiffness such that the structural and track bed movements are acceptably small, and future settlement is mitigated to less than 20 mm, with a maximum of 10mm occurring following the track installation. Verification testing to prove that design requirements have been achieved included coring and testing of samples, as well as zone load pressure test. As such the design necessitated a grid of 2.0m diameter DSM columns with target UCS strength of 0.75 MPa. A load transfer platform (LTP) of 0.5m thickness enclosing 2 layers of geogrid was provided on the top of the treated ground to enhance and ensure uniform transfer of the loads.

Oct 31, 2023

By Md Kausar Anik, Ramin Motamed, Peiman Zogh

The earthquakes that occurred in New Zealand and Japan in 2010 and 2011 caused significant damage due to liquefaction. Engineers have adopted various ground improvement techniques to reduce the impact of liquefaction-induced damage, and one of these techniques is installing a sheet pile next to the foundation. However, the optimal depth into a non-liquefiable soil layer for having appropriate fixity of the bottom of the sheet pile remains unclear. To address this issue, a series of moderate-scale 1g shake table tests were conducted to evaluate the effective embedment depth of the sheet pile required to mitigate liquefaction-induced foundation settlement. A 1/5 scaled model consisting of three soil layers with varying densities, namely the crust, liquefiable, and dense layers, was prepared. A shallow foundation was placed over the crust layer and a sheet pile at a horizontal distance of 0.625 times the foundation length from the center of the foundation was inserted into the soil at various embedment depths using the press-in technique. The test results indicated that the foundation settlement could be reduced by 62% and 72% when the sheet pile was embedded to 50% and 100% of the dense layer thickness. It was recommended that the sheet pile be embedded at least 50% of the firm stratum thickness to achieve optimal performance.

Oct 31, 2023