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By Joseph A. Sopko

The first documented procedures for designing frozen earth structures are over 50 years old, implemented long before the introduction of the Finite Element Method (FEM). Since that time, the development of three-dimensional models has made the traditional and often over-conservative methods relatively obsolete. This paper discusses a new approach that is largely dependent on the analysis of internal stresses with the frozen structure and comparison to frozen soil laboratory tests. A specific design process is discussed related to initial field investigation, laboratory testing, structural and thermal analysis, and performance monitoring. The design results are compared to case histories in the field that verify the procedure. BACKGROUND One of the first documented methods to designing frozen earth retaining structures was by Sangar (1968). Methodical refinements were published by (Harris 1995) and published by the International Symposium on Ground Freezing in 2002 (Andersland et al. 1991). The structural design or thickness of the frozen mass was based on the unconfined compressive strength of the frozen soils. Two simple equations for determining the thickness of a frozen shaft are shown in Fig. 1 and the first two equations below.

Jan 1, 2019

By Seiji Mizutani, Hirofumi Taguchi, Makoto Yoshida, Hidenori Takahashi, Naotoshi Shinkawa, Kazuo Konishi, Yoshiyuki Morikawa, Masaya Kawata

"The lattice-shaped cement treatment method has been used to improve the seismic performance of liquefied sandy soil in Japan. The efficacy of the method has been confirmed by the huge earthquake in Japan. In the present study, a new method to improve sandy ground by using the lattice-shaped cement treatment method is proposed as a liquefaction countermeasure. It is the floating-type and lattice-shaped cement treatment method, where cement treated soil is not fixed to an un-liquefiable stratum. In this method, a fixed-type structure such as treated soil should be formed at the side of the floating-type treated soil to reduce its lateral displacement. In the study, one-dimensional dynamic response analyses were firstly conducted to confirm the mechanism of the new method. Secondly, a series of centrifuge model tests were performed to demonstrate the effect in a proto-type scale's stress condition. The analyses and model tests confirmed the effect of liquefaction countermeasure of the new method.INTRODUCTIONLiquefaction induced by an earthquake generates sand boiling and ground settlement. Other problems have also been reported, including a decrease in bearing capacity and an increase in the horizontal earth pressure against retaining walls. To prevent these problems caused by liquefaction of the ground, various countermeasures have been proposed, such as cement deep mixing and high-pressure jet mixing methods. These methods have the big advantage of being applicable to ground that contains soil with a fine-grain fraction. Furthermore, the unnecessary displacement caused by the construction can be reduced. In Japan, a lattice-shaped cement-treatment method has frequently been used at many construction sites to prevent liquefaction, where cement-treated piles are intersected to form a lattice, as shown in Fig. 1. The lattice-shaped walls can reduce the shear stress generated by an earthquake, restricting the liquefaction at that location. However, the construction cost of the cement treatment is relatively high compared to other methods such as the sand compaction pile (SCP) method, and needs to be reduced. Therefore, decreasing the total volume of the cement treatment is necessary to reduce the construction cost."

Jan 1, 2015

By Michael H. Wysockey

The load test program for the pile foundation at Soldier Field included static and dynamic load tests at four locations around the site. The dynamic tests were run with no knowledge of the static results, and comparison between the two is very good. It was necessary to use a special testing hammer (not the production hammer) to demonstrate capacity with dynamic testing. Over 90% of the piles were HP14x89 with a design load of 230 tons (18 ksi). The load tests showed a capacity in excess of 590 tons for all tests where sufficient set up time was allowed. The remainder of the piles were mostly HP 12x53 with a design load of 100 tons (13 ksi). The measured capacity of these piles was typically about 250 tons. One experimental HP12×74 pile with a nominal yield of 65 ksi held 730 tons (67 ksi) before failing.

Jan 1, 2002

By Paul J. Axtell

This case history describes the foundation design and construction for the New Mississippi River Bridge, presently under construction in St. Louis, Missouri. The 1,500 ft (457.2 m) main span of the cable-stayed bridge is supported by two delta tower pylons in the river, with anchor piers on each bank. The final foundation design was completed as a part of an Alternate Technical Concept (ATC) proposal by the winning construction team, and utilized drilled shafts up to 11.5-ft (3.5-m) diameter that were socketed into very hard limestone. As part of the ATC foundation design, a full-scale, bi-directional static load test was performed to verify the design and allow use of higher resistance values. This paper presents the results of the site exploration, construction of the load test shaft, details of the load testing, and a comparison of the test results with various design parameters.

Jan 1, 2011

By K. Y. C. Chung

A case study on foundation engineering through organic soils is presented. Located along the west shore of the Hudson River, site soils consist of random brick fill over a thick layer of peat and organic silts or clays. The organic layer is underlain by medium dense to dense sand with varying amounts of silt. Strong artesian pressures were measured in the sand. A pile foundation system was selected to support all structures. To avoid periodic flooding, new fill must be placed on the existing fill. Large total and differential settlements will occur due to consolidation and secondary compression of the organic soils. This settlement will reduce the allowable pile capacity due to the large negative skin friction in the organic layer; and will necessitate long-term maintenance of the final grade elevation. Pile load tests were performed to determine the allowable compression and uplift capacities, long-term capacities and pile driving criteria.

Jan 1, 2010

By Jim Henry

I would say mainly the cost. I showed only 3 cases. One of them was the one that Allen just described and there were two other cases. In those cases it was fairly easy to develop a solution using limited mobility grout to treat the soft soils suitable for the limited bearing pressures required by the structures. LMG readily provided a fairly reliable system for the foundation support at a reasonable cost.

Feb 10, 2003

By Rich A. Lamb, Paul J. Axtell, Michael K. Muchard

"Since 2010, the Minnesota Department of Transportation (MnDOT) has performed eight full-scale compressive load tests on large-diameter pipe piles at four different project locations across the state. All of the piles were 42-in diameter, open-ended pipes driven to practical refusal on sedimentary bedrock with D125-32 diesel hammers from three separate manufacturers. The rapid load test method in general accordance with ASTM D7383-10 (Statnamic method) was used along with high-strain dynamic testing and subsequent signal matching. Results of these tests indicate that the axial nominal resistance of these piles in compression is not controlled by geotechnical considerations when driven with an appropriately sized hammer and installation criterion. Rather, the predominantly elastic load-deflection behavior of the piles under compressive load suggests the axial nominal compressive resistance is controlled by the structural capacity of the pile. In all instances, the rapid load tests indicated a nominal resistance exceeding that produced by high-strain dynamic tests due to insufficient hammer energy to fully mobilize resistance. In all cases, the hammers used were able to easily install the piles through the soil overburden. Mobilizing a larger hammer simply to demonstrate high-strain dynamic resistance is not economical or practical. This paper presents the subsurface conditions at each location, the ensuing test results, and the ramifications for future projects in Minnesota utilizing large-diameter open-ended pipe piles.INTRODUCTIONThe Minnesota Department of Transportation (MnDOT) has recently performed eight full-scale compressive load tests on large-diameter pipe piles at four different project locations across the state. The four project locations described in this paper where pile load testing was performed are shown in Figure 1 and exist in the southeastern portion of Minnesota. The projects are all major bridges crossing the Mississippi River in three instances and the St. Croix River just above the Mississippi River in the other instance. The first project is the TH 61 Mississippi River crossing in Hasting, MN where two load tests were conducted. The second is the TH 36 St. Croix River crossing in Stillwater, MN where two load tests were performed. The third project is the I-90 Mississippi River crossing in Dresbach, MN where three load tests were conducted. The final project is the TH 43 Mississippi River crossing in Winona, MN where one load test was performed."

Jan 1, 2017

By Jim Bruce

No answer required. From the drilling equipment suppliers, but the specifications must be tailored to be project-specific. Yes, the sonic technique is very interesting as we said, and it is not so much as an issue of the magnitude of power, it's about the efficient use of the power. The efficiency of the machine is not necessarily related to size so it is best to talk to the two contractors that supply the service about that. I think it can be scaled down but it is quite a big head, so therefore there are practical limitations on the size of the door it can walk through and also the size of the casings and rods that it can use. You might defeat the economic advantages if you were to use too short casing lengths. Boart Longyear have a low head room machine that can work within an 8 foot verical clearance.

Feb 10, 2003

By Ashirbad Satapathy, Sanket Rawat, Ramanand Shukla, Ravi Kant Mittal

Bearing capacity factor (Nq) and Adhesion factor (α) are the key parameters for analyzing the load carrying capacity of pile foundations embedded in cohesionless and cohesive soils respectively. Numerous models are available in the form of charts or equations for the computation of these parameters and hence, have been adopted by most of the International and National standards. Indian Standard for the Design and Construction of Concrete Pile Foundations, IS 2911–Part 1 (2010), also makes use of charts detailed in its Annexure B. However, the sources of these charts have not been specified clearly, making it difficult to back-refer to the actual models to assess their basis for resolving any critical scenarios encountered during design. The present study aims at acquiring a distinct understanding of the development of these charts in order to bring more clarity to the design process of pile foundations. The given charts have been compared with various models specified in existing literature and international standards for the calculation of Nq and α for both driven and bored piles and hence, the basis of Indian Standard charts has been identified. Moreover, it is evident that the use of these charts complicates the process of automation of analysis and design of pile foundations as well as the associated optimization studies. Additionally, the manual entry of data especially, from the logarithmic graph of Nq, escalates the chances of error thus, making it a critical concern for design offices. Therefore, this paper also presents a non-linear regression model for Nq and α, developed using NCSS software for both driven and bored piles. Through multiple iterations, the value of coefficient of determination for Nq and α has been found to reach greater than 0.995. The developed equations can be simplistically used for both manual and automated analysis of pile foundations.

Nov 1, 2022

By Emre Turk, Suat Gullu, Candan Gokceoglu, Ahmet Sirri, Asli Can

In this study, the ground improvement application applied under the live railway bridge's approach embankments in Sivas, Türkiye was investigated as a case study. The soil profile is mainly composed of orangish conglomerate, clay, silty sandy clay, and under claystone, and mudstone units in the study area. As a soil improvement method, the Deep Soil Mixing (DSM) technique based on the principle of simultaneous mixing the ground while injecting with the water-cement mix, was selected. The application of DSM columns is designed to be 45 degrees horizontal, in order to reach the deepest point of the soft clay units for better improvement against settlement. The core samples were taken from the DSM columns and the compressive strength tests were performed in the laboratory. The results were higher than the minimum designed values. It means that inclined DSM columns were applied successfully, and the excessive settlement problem was solved.

Oct 1, 2022

By R. Lee Wooten, David R. Shields, Darren D. Clark

"Borehole permeability tests that measure flow or head changes in boreholes located within seepage barrier walls are commonly used to estimate the in situ permeabilities of those walls for quality control and assurance. The current state of practice for estimating permeabilities from these barrier wall borehole tests is to use equations published by M. J. Hvorslev in 1951. Hvorslev’s borehole test equations model an infinite stratum of uniform permeability, which is not the actual condition for a test performed in a low permeability barrier wall located within a high permeability stratum. We examine and develop alternative equations based on line source analytical models, which more closely match barrier wall test conditions. We describe how these alternate equations can be used to estimate barrier wall permeabilities from borehole tests and compare the results to those obtained from the Hvorslev models. We also provide recommendations that consider differing upstream and downstream water levels.Barrier Wall Permeability Tests - State Of PracticeThe installation of seepage barrier walls has become more common in a variety of applications ranging from dams and levees to contaminated sites requiring retardation of groundwater flow. The types of seepage barrier walls and installation methods include soil-bentonite, soil-cement-bentonite, concrete, self-hardening slurry, geomembranes, and sheet piles, installed with various soil mixing, slurry-supported trench, and driving methods.Owners and contractors have used a variety of methods to evaluate the permeability of these seepage barriers. The following table lists commonly used quality control/assurance tests for evaluating the permeability of a seepage barrier."

Jan 1, 2016

By Vincent Tirolo

Two separate secant pile cofferdams were constructed as part of an extensive rehabilitation and modernization of the New York City Transit's Lexington Avenue/Third Avenue IND Station at 53rd Street in Manhattan. Major high rise structures and outpatient hospital facilities bordered the site. The roadway is an important east-west corridor in mid-Manhattan. In order to perform the construction of new escalator and elevator shafts over 250 linear feet of secant wall was installed to the top of rock or to the existing subway roof. Much of the secant wall was constructed from below a temporary roadway decking system using a low headroom rig. The roadway decking system was supported on shallow spread footings. The secant piles were drilled using crawler mounted hydraulic rotary drill rigs. The secant wall provided a watertight, rigid cofferdam that minimized settlement and other disruptions to existing structures and utilities. During later stages of the project the secant wall also supported the roadway decking system.

Jan 1, 2003

By Mark R. Svinkin

Regulations are needed to keep construction vibrations in tolerable limits. The existing regulations were developed for low-rise residential structures, but they are incorrectly used for different super and underground structures. The existing regulations cannot prevent most of harmful vibration effects on sensitive devices, people and structures from construction and industrial vibration sources. It is important to determine the areas of application of the existing regulations and bring attention to the necessity of measurement of the structural responses for assessment of vibration effects on structures. For multi-story residential, commercial and industrial buildings, the frequency-independent safe limit of 51 mm/s (2 in./s) can be chosen for the peak particle velocity of structural, not ground, vibrations. Specifications for construction operations with dynamic sources have to consider specifics of each construction site. Preventive measures can be used to mitigate harmful vibration effects on various structures and settlements in sand and clay soils.

Jan 1, 2006

By Larry Rayburn

In the spring of 1999, construction commenced on the new Steelers Football Stadium in downtown Pittsburgh, Pennsylvania. Richard Goettle, Inc. (RGI) was the successful bidder to install the specified augercast piles for the foundation package. Description - Pittsburgh Steelers Stadium The new stadium will house the Pittsburgh Steelers Professional Football Team. It is widely believed that if a team is provided with a modern playing facility, that a winning season will ensue (Not always the case). The new stadium location is on the north side of Pittsburgh on the Ohio River, and just downstream of the confluence of the Monongahela and Allegheny Rivers. The site is west of existing Three Rivers Stadium. The Three Rivers Stadium was built during the late sixties and housed both the Pirates Baseball and Steelers Football Teams. The Public Auditorium Authority elected to replace this outdated stadium with two new stadiums, one for each professional team. The landmark stadium was imploded in February of 2001.

Jan 1, 2001

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 Dale Berner, Michael O’Sullivan

"This article focuses on lessons learned from innovative designs including in-the-wet construction methodology and modified foundation conditions, for two United States Army Corps of Engineers (USACE) megaprojects. Olmsted Dam FoundationThe over $2 billion Olmsted Dam on the Ohio River is currently under construction 16 mi (29.6 km) upstream from the confluence with the Mississippi River. The project is under the jurisdiction of the Louisville District of the USACE. It will consist of an 800 ft (244 m) long tainter gate section, a 1,400 ft (427 m) navigable pass, two boat abutment sections, a fixed weir section, and upstream and downstream scour protection. The Olmsted Dam and its two 1,200 ft (366 m) locks, which were built in 2002, will eventually replace both Locks and Dam #52 and #53, both built in 1929, and thereby bring significant benefits to the Ohio River navigation system.In 2002, the Jacobs/COWI JV completed the design of the dam; which was an engineering challenge for several reasons. A significant consideration was its proximity to the New Madrid Fault, which could impose an 8.4 Richter scale seismic event on the structure, which is located in an area of potentially liquefiable alluvium. The extensive seismic analysis performed by the designer included a response spectra analyses, lateral pushover analyses of pile foundations, hydrodynamic added masses, pile group effects, and the development of kinematic motions as a result of the soil-pilestructure interaction."

Jan 1, 2016

"After the non-destructive testing is completed, the data must be compiled, evaluated, and interpreted. During this process, the data may indicate that there is an anomaly warranting further investigation, which may eventually be determined to be a flaw or defect. The definitions of an anomaly, flaw, and defect can be described as follows (after Amir, 2002):Anomaly - Any irregular feature identified in the NDT graphic results. An anomaly may be due to the testing instrumentation (such as noise), to the means used to perform the test (e.g. access tube debonding in CSL) or to the shaft itself. It is the responsibility of the NDT practitioner to gather and analyze all relevant data and try to resolve every anomaly before it is declared a flaw or defect.Flaw - Any deviation from the planned shape, size and/or material of the shaft.Defect - A flaw that, because of either size or location, may detract from the shaft’s intended performance or durability. The geotechnical engineer and the structural engineer are jointly responsible to decide which flaw comprises a defect.This section describes the process of evaluating the data, determining if an anomaly exists, and if so, deciding whether the anomaly is actually a flaw or a defect. If the anomaly is determined to be a defect, its effect on the performance of the shaft must be evaluated, and if necessary, the can be re-engineered, repaired, or replaced."

Jan 1, 2004

By Sherif Elfass, Gary Norris

Bi-directional load testing of drilled shafts has been widely adopted as a means to evaluate their load carrying capacity. However, in order to reach failure, most of these tests are carried out on sacrificial shafts using expensive sacrificial elements such as hydraulic jacks. A proposed low-cost bi-directional testing technique is discussed. It mechanically loads the end bearing soil below a drilled shaft, against its side shear resistance. The technique was originally established as an alternative to post-grouting to reliably account for the forfeited end bearing resistance. However, since it loads the shaft in a manner similar to conventional bi-directional tests, it can be used to not only load test sacrificial shafts, but production shafts as well. Furthermore, unlike conventional bi-directional load tests, the load is applied through surface jacks. These jacks, along with other load test components, are movable and can be reused to load test all the shafts of the project thus presenting an economic benefit. The concept of this technique has received favorable feedback from a few consulted departments of transportation, and while promising, has not been field tested to date. A U.S. patent was issued for the tip loading module and the loading technique described.

Sep 8, 2021

By Brandon Smith, William Bohlen

Riverbank erosion along the Brazos River has modified the structural support conditions for an existing bridge structure in Southeast Texas. The 8-span, 1,200-foot long bridge was completed in 1992 along Highway 99, a key corridor for the Houston area. Foundation support conditions have been altered due to natural, ongoing river morphology for three bents on the affected riverbank. Recent events include three storms within a three-year period that each exceeded the 500-year return probability. This resulted in accelerated erosion along the northern riverbank. Over forty vertical feet of soil has been removed in some locations. Drilled shaft foundations are now functioning as columns. This review considers the behavior of columns and deep foundation elements due to the modified support conditions. The review ultimately presents a rational methodology for the review of the present and anticipated future bridge configuration with respect to current strength, service, and extreme event limits, with corresponding safety factors for the design. Introduction and Background The Fort Bend Grand Parkway Toll Road Authority (Owner) oversees the State Highway 99 Judge Jodie Stavinoha Bridge over the Brazos River. The 8-span, 1,200-foot long bridge was originally designed with four southern approach spans of 115 feet; a three-span continuous river crossing with span lengths of 195 feet-235 feet-195 feet; and a single northern approach span of 115 feet. Figure 1 provides an overview of the northern portion of the bridge. Table 1 provides a summary of the original bridge substructure configuration. When the bridge was completed, the centerline of the Brazos River was located at midpsan of the main span and the northern high bank was originally located at Bent 7. Erosion process has forced the northern high bank to Abutment 9 (also called Bent 9), and the river centerline during normal flow conditions is located south of Bent 8. The overall estimated river excursion at present day is approximately 270 feet to the north from its original location. An erosion wall that was installed in 2017 limits further erosion of the north river bank within the 300-foot width of the roadway corridor right-of-way. This study was developed to better understand the existing conditions, and to forecast the need, nature, and criteria for potential future improvements.

Jan 1, 2019

By Vivek Samu, Murthy Guddati

A new method called Effective Dispersion Analysis of Reflections (EDAR) was recently developed to effectively analyze the dispersive waves generated from lateral impact to piles. This paper presents the results of nondestructive length estimation of existing piles through EDAR. EDAR provides a new visualization method for analyzing wave reflections by transforming the response into the frequency domain thus eliminating the need to perform difficult peak picking in the time domain. In addition to being able to analyze dispersive waves, EDAR also incorporates the effects of radiation damping due to the surrounding soil leading to more accurate length estimates. Concrete filled steel tubes of different embedment depths were tested both in laboratory and field conditions. Length estimates obtained were within 10% error margins after careful analysis accounting for the presence of soil effects and effects from pile top reflection.