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By Meeok Kim, Thornton Tomasetti, Seth Knihtila, Michael Oakland, Shawn Leary

The transformation of Seattle's historic KeyArena into the state-of-the-art Climate Pledge Arena, home to the NHL's Seattle Kraken, was no small feat. The $930-million renovation and expansion required the near-total demolition of the old structure and construction of an 800,000 sqf (74,000 m2), below grade venue while keeping its landmarked façade and roof intact. To do that, the project team had to come up with solutions for excavating 680,000 cu yd (520,000 m3) of soil to make way for the new 17,000-seat arena while working around the massive temporary shoring supporting the 44 million lb (20 million kg) roof all in time for the NHL's 2021-22 season.

Sep 1, 2023

By Karen Dawson

Pressure-grouted helical piles support a new seven-story homeless housing center in the Coney Island neighborhood of Brooklyn, New York. The project team instrumented and statically load tested piles to as much as 1,000 kips (4.4 MN) in advance of construction to obtain the approval of the New York City Building Code officials and to verify the design. Use of pressure-grouted helical piles required additional design effort and time risk because of New York City's Construction Code Determination (CCD1) process, which is required for non- standard deep foundation types. Despite

May 1, 2022

By Rasin Duzceer

In this paper, the results of pile load test on 24 piles from twelve sites are presented. The pile load tests were performed on 14 driven and 10 bored piles of varying diameters and lengths installed in different ground conditions in Turkey, Saudi Arabia and Kazakhstan. The purpose of this study is to evaluate and compare the axial capacity of the piles obtained using pile load test interpretation methods. Davisson, Brinch Hansen %80, Chin-Kondner, Shen-Niu, De-Beer, Housel, Mazurkiewicz, Fuller-Hoy, Brinch- Hansen (90%), Corps of Engineers, Butler Hoy and Tangent Intersection methods were used to determine the axial capacity of the piles. Static analysis using FHWA method was performed to predict the axial capacity of the piles. A statistical analysis was performed to compare and quantify the load test interpretation methods. The ratio of interpreted (Qi) to predicted (Qp) pile capacity was compared for each method. For each pile load test and for each interpretation method, the mean and coefficient of variation of (Qi)/ (Qp) were calculated. Among twelve methods investigated, the highest Qi/Qp value was obtained as 1.37 for Chin-Kondner method whereas the lowest Qi/Qp ratio of 0.70 was obtained from De Beer method.

Jan 1, 2002

By Safwan Labanieh

An experimental set-up is specially designed to study the behavior of a friction pile of 3 cm diameter in contact with the soft clay of Mexico City in a small calibration chamber (CC) of 30 cm diameter and 50 cm height. The consolidation of this compressible clay is accomplished using a special system adapted to the CC itself to insure a good knowledge of the initial state. Loading results of the pile under a consolidation pressure of 50 kPa indicate an elastic mobilization of shear stresses at the shaft of the pile (?3 kPa for 1mm displacement) followed by a hardening plastic type behavior. Unloading-reloading results indicate a mobilization of shear stresses of the same type and of the same order of values obtained from the virgin loading stress path. Cyclic loading (?40 cycles) between 0 and 1 kPa (1/3 of the failure value) give similar results to those obtained from virgin loading.

Jan 1, 2002

By Georgette Hlepas

How often phrases like these have been made by project managers and project teams trying to explain why there has been cost growth, project delays and differing site conditions claims. But does it really take x-ray vision? Do we really approach geotechnical construction projects unprepared for the subsurface that may be encountered because we can't get the answer? Too often our industry seems to think the answer is, "yes." However, this is not because we can't understand the subsurface. All too frequently it is because a choice is made to save money or time by foregoing or shortchanging upfront subsurface investigations. This is accepting a risk at the beginning of the process and realizing it during construction. Case histories have proven time and time again that upfront investment in site exploration and constructing a ground model mitigates risk in design and construction. But how much do we prepare? What level of investigation (or investment) is appropriate? The answer of course, is it depends; how much risk are you willing to take for your project and what are the potential consequences?

May 1, 2022

By Kam Ng

For bridges or buildings that may be subjected to large vertical and lateral loads, drilled shafts offer an economic foundation solution. While the current drilled shaft design practice is considered adequate, introducing a performance-based approach to designing the drilled shafts will make their design more cost-effective and produce more dependable response. This concept was examined using analysis of 41 drilled shaft load test data from several states. This process identified the challenge with the lack of information from the Osterberg (O-cell) load test method to characterize the full top load-displacement response. When a typical single O-cell is utilized in a drilled shaft test, depending on the location of the O-cell and the geomaterials present along and beneath the shaft, the load test result typically quantifies either the side resistance or end bearing reaching the ultimate load-displacement curve but not both components. This limitation hinders the determination of a suitable shaft resistance as a function of a target top displacement. To overcome this challenge, an improved procedure is proposed for establishing the full load-displacement curve based on data gathered from one O-cell. The method will be presented in the paper for three different cases (i.e., side resistance reaches the ultimate during the test, end bearing reaches the ultimate during the test, and neither components reach the ultimate values). Because it allows the characterization of the full load-displacement curve, the proposed procedure will allow performance-based design of drilled shafts with due consideration to settlement while satisfying the Load and Resistance Factor Design.

Jan 1, 2013

By L. J. Whitworth

Five trial piles were constructed during the trial pile programme for the Birmingham International Convention Centre. In addition, trial piles have been tested on two other sites in central Birmingham. Methods of pile construction were conventional sandstone rock sockets, sleeved piles and voided piles. The results of these load tests are compared with the theoretical predicted behaviour based on the results of unconfined compressive tests of rock core taken on the Convention Centre site and on other sites in the central Birmingham area. On the basis of this work, the various design procedures are discussed.

Jan 1, 1989

By Kashyap Chaturvedula, Emad Farouz

The paper presents a discussion on the axial capacity of deep foundation elements bearing in the Yorktown formation in the southeastern region of Virginia. The fossiliferous marine soils of Tertiary age Yorktown formation typically consist of silty/clayey Sand or sandy Silt/Clay with varying amounts of shell fragments. The Yorktown formation is generally divided into Upper and Lower Yorktown layers depending on the shell content and the percent fines. Results of multiple load tests performed by Jacobs Engineering on auger cast piles as part of water and wastewater treatment plant expansion projects in southeastern region of Virginia are presented in this paper. The paper describes the subsurface investigation methods used to study the existing subsurface conditions and the design methodologies followed to estimate the axial capacity of the auger cast piles. The paper provides details regarding installation of test piles, instrumentation, load testing procedure, and interpretation of test results. The paper presents a comparison between the various methods of estimating axial capacity of auger cast piles based on the SPT-N values, the empirical methods for the Yorktown formation and the load test information. The paper distinguishes the side resistance values obtained within the upper and lower Yorktown formations. The paper compares the various design methods to the multiple load test results and recommends a design modification that is closer to the load test results.

By Ben C. Gerwick

This publication is intended to document recent innovations and technologies that have the best potential for effectively improving the quality of marine foundations while reducing the cost, time and risk of construction. Marine foundations originated in Neolithic times with the Swiss Lake Dwellers who constructed pile-supported houses, safe from invading tribes. The Queen of Babylonia built the first recorded bridge in 1500 BC across the Tigris. The foundations were large flat stones laid on the river bottom. About the same time in India, builders extended their water well techniques to the construction of ?well? foundations in the beds of their rivers. These were really the first open caissons; brick walls were built up in a circular ring while divers excavated sand from the bottom, sometimes at a depth of 100 feet. The Romans extended the clay-filled cribs of the Middle East to shallow cofferdams, which they sealed by underwater concrete made with pozzolanic cement from Mt. Vesuvius.

Jan 1, 2013

By Rodrigue Karam

An assessment of the geotechnical conditions at the Manhattan Cruise Terminals (Piers 88, 90, 92 & 94) was conducted after excessive settlement and structural distress was reported at Pier 92. The piers are located on the Hudson River along the west side of Manhattan, New York. The following paper focuses on the investigation and analysis performed on Pier 88 located at the western terminus of 48th Street. The pier is supported by approximately 2,500 timber piles bearing on soft organic silts and clays. The first portion of the analysis consisted of an offshore field investigation and laboratory testing to classify the subsurface soils within the project area and estimate the geotechnical capacities of the timber piles. Additionally, a settlement analysis including consolidation and negative skin friction analyses was performed to evaluate existing settlement levels. Axial and lateral analyses were performed to develop the soil springs (p-y, t-z, and q-z curves) necessary for the structural analysis.

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 W. Morgan NeSmith

The city of Kansas City, Missouri, is replacing its original airport, con- structed in 1972 as a "drive-to-the- gate" facility, with a modern, single- terminal facility with just over 1 million sq ft (92,903 sq m) in area along with an adjacent 6,300-space parking structure. It is the largest infrastructure project in the city's history. The project team designed and oversaw the installation of 12-24 in (305-610 mm) diameter augered cast- in-place (ACIP) piles to a range of depths with the pile toes located in underlying alluvial clay, weathered shale or on intact limestone, depending on the required loads at each column location. The specific ACIP piles used were auger pressure grouted (APG) piles. Additional information regarding the ACIP pile installation process can be found in the Augered Cast-in-Place Pile Manual, Third Edition (2016) prepared by the DFI Augered Cast-in-Place and Drilled Displacement Pile Committee. This article includes a summary of the subsurface conditions, the foundation support requirements, the extensive performance test program - started before production installation but not completed until well into production phase of the project - and the resulting production pile installation require- ments. The approach resulted in about $700,000 in foundation program savings to the city. The reduced con- struction time of about 10% less than originally estimated also added to the overall savings beyond the direct foundation savings.

Oct 1, 2022

By Stephen T. Bloomer

The application of a direct current electrical potential between a metallic pile and a fine grained soil results in an almost instantaneous change in the magnitude of the forces acting on the pile. During installation, with the pile connected as a cathode, the driving force needed can be reduced dramatically. Reversal of the polarity results in an increase in ultimate bearing capacity. The cause of the aforementioned phenomenon has been investigated and found to be two-fold; ie the electro-osmotic transport of pore-water and the electro-chemical hardening of the clay in close proximity to the pile. In the case of the former effect, the pore-water is transported towards the cathodic pile resulting in a temporary, reversible change in the engineering properties of the clay surrounding the pile. This effect is represented by a change in Skempton's Adhesion Factor (a). A total of one hundred and forty eight model tests was undertaken to study the change in the a valve using different types of metallic pile. The tests revealed changes in bearing capacity related to embedded length, skin-friction, end bearing and electro-osmotic gradient. It was shown in skin-friction-only tests that variations in soils strength across the soil profile caused by the electro-osmosis caused resultant changes in bearing capacity. This work is being carried out with the collaboration of Hercules Piling, a subsidiary of Stent Foundation Ltd.

Jan 1, 1996

By Emad Farouz, Ehab S. Shatnawi, Charles Winter

The increasing demand for small deformations and high-capacity drilled shafts without enlarging drilled-shaft diameters has motivated the development and increased use of a base grouting (BG) technique. This technique has been demonstrated to improve drilled-shaft axial capacity, especially for shafts tipped into loose cohesionless soils. To date, there are a couple of documented design methods for estimating the axial geotechnical resistance of base-grouted shafts. However, there is no or lack of research that addresses the lateral response of such shafts. A base-grouted drilled shaft test program was carried out during the design phase of the Wisconsin I-94 Zoo Interchange reconstruction project. The test program included installing and testing one base-grouted shaft and one ungrouted shaft under both lateral and axial loading. Based on test results, it was concluded that the lateral behavior of the BG drilled shaft is significantly stiffer than conventional drilled shaft . Hypothetical method was developed to account for potential increased, however, the method should be verified with more lateral load test.

By Michal Topolnicki

Deep Mixing Series: This article is the second keynote highlighted from DFI's virtual Deep Mixing Conference in 2021, for which Topolnicki served as a committeee co-chair Polish applications of deep soil mixing (DSM) technology occupy a leading position in Europe. That includes use for road and railway embankments, bridges, residential and industrial build- ings, silos, commercial centers, slabs, car parks and storage yards, excavation supports and cut-off walls. In fact, more than 350 road and railway viaducts and 200 wind turbines have been founded nationally on DSM columns, which are firsts on an international scale. This represents more than 1,200 imple- mentations by the Polish geotechnical industry. Considering the need to update DSM design recommendations, this article will attempt to summarize the best practices of wet DSM design and implementation, in particular. It draws on 20 years of experience and will high- light the properties and principles of the design of stabilized soil and lessons learned. Case studies are included to fur- ther understanding of the careful con- siderations needed with this technology.

Apr 1, 2022

By X. Y. Hou

The design practice of several circular underground projects with large diameter is summarized. By taking the advantages of load-bearing of circular structure, a rational annular tensile bar support system and a new design method are proposed. Calculation for a car park shows that remarkable results are brought in by this design technique.

Jan 1, 2010

By Peter Arz

In the port of Hamburg a 650 m long quay wall was completed in mid-1985. The watertight wall consists of loadbearing steel buttress piles PSP 1012 which are up to 28 m long and infill interlocking sheet piles PZ 612. The construction method used for this quay wall, which included the simultaneous implementation of ground improvement measures, is the subject of this lecture. Originally, as is common practice, driving of the sheet piles had been envisaged. The composition of the subsoil, which consists of fill, clay, sand and boulder clay, is typical of the Hamburg region. In the upper layers (down to a depth of approx. 15 m), the subsoil is interspersed with debris from ancient civilisations but also dating from the war and post-war period (bomb craters filled with debris and demolition material).

Jan 1, 1987

By Thomas Kennedy, Michael Bennett

"History never repeats itself, but it often rhymes." The old aphorism reflects how the study of the past may, perhaps, be most widely valued when it can be used to improve current and future decision making. The education the authors received as geotechnical graduate students certainly impressed upon them the importance of recognizing that not all wisdom is necessarily new. Much of their graduate coursework involved reading technical papers that had introduced concepts of outstanding historical significance in the field, such as pore pressure coefficients, stress paths, and the stress history and nor- malized soil engineering model. These papers gave the authors both respect for and interest in the historical develop- ment of the field. After graduation, the authors furthered and deepened this interest by continuing to expand their knowledge of the profession through both experience in practice and the review of additional literature.

Jan 1, 2023

By Nathan Iverson, Allie Brady

Located on rolling bluffs on the Zumbro River's south fork in Southeast Minnesota, Rochester is the state's third largest city and is the home and birthplace of the renowned Mayo Clinic, a nonprofit academic medical center focused on integrated health care, education and research. Mayo Clinic employs more than 4,500 physicians and scientists with another 58,000 administrative and allied health staff across three major campuses: Rochester, Minnesota; Jacksonville, Florida; and Phoenix/Scottsdale, Arizona. Originally developed as a stagecoach stop, Rochester has become a national destination for medical care, drawing more than two million visitors annually to Mayo's Minnesota location. Since January 2022, Veit & Company has been working on the construction of the Mayo 1st Ave Tunnel, which comprises three tunnels (pedestrian, utility and services), and the RMC Loading Dock projects in Rochester. These adjacent projects are on the Mayo Clinic's ever-expanding campus and represent its continued dedication to improvement and advancement as a leading medical service provider in the industry.

Jan 1, 2023

By Y. W. Mou

In order to improve the construction of pile foundations and deep foundations of largo sizes, the paper deals with the method of installing square or rectangular bored-piles for annular foundation as well as large-sized hollow or solid foundation.

Jan 1, 2010