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By Harry K. Weatherbee

The paper presents a design case study for a four-story correction facility addition in south Boston, Massachusetts, supported on friction piles driven into the Boston Blue Clay. 356 mm (14-in.) square prestressed-precast (PSPC) concrete piles were selected as they were found more effective and economical. A static load test was performed where the pile was brought to "failure". The load test data were evaluated to estimate the Ultimate Pile Capacity as well as the Ultimate Unit Skin Friction (Adhesion) to serve as a design tool for friction pile projects in the south Boston Area.

Jan 1, 2003

By J. Matos e Silva

The paper refers two examples of structures located in seismic areas (Cases 1 and 2). The first one (Case 1) is the Torroal Bridge, located about 100 Km South of Lisbon, in the road Troia-Grandola. The horizontal loads due to the seismic actions were mainly carried by an anchor curtain connected, to the abutments, by reinforced concrete struts-ties. For the some purpose diaphragm walls were also placed under the pile caps of the column foundations. The second one (Case 2) refers to a building located about 50 Km South of Lisbon, at Sesimbra, near a cliff. To reduce the horizontal displacements of the structure due to seismic actions, in order to prevent the endangering of the cliff stability, an anchor curtain was adopted and connected, to the structure, by prestressed anchors.

Jan 1, 1996

By M. Reza Saberi, T. Ted Miyake

Driven piles are a common tool in any engineer’s toolbox for supporting large structures over very soft ground, especially in high seismic risk zones. Challenges include achieving sufficient vertical and lateral load capacities within the constraints of pile spacing and geologic conditions. This was the case for a project in Orange County, California with a state-of-the-art, $180 million plant for biosolids processing, biogas management and energy recovery located in marshland next to an existing waste water treatment plant. The new construction for the Irvine Ranch Water District included a 70-foot (21 m) tall building and three closely spaced, 90-foot (27 m) high, 65-foot (20 m) diameter, egg-shaped steel digester tanks. The lower 35-feet (11 m) of the tanks were constructed below ground level. The site was underlain by up to 45 feet (14 m) of highly compressible peat and organic clays with standard penetration test (SPT) blows as low as 2 blows/ft (30 cm). Some of the peat layers had measured in-situ dry densities of less than 30 pcf (480 kg/m3) with moisture contents of over 250 percent. The soft clays and peat were underlain by a dense layer of sand and gravel at depth. Groundwater was very shallow. While nearby sites were designated by others as seismic site class “D”, this site was clearly class “F” (SF) which required site specific seismic hazard and time history analyses. Six recorded time histories were selected from the 1994 Northridge, 1989 Loma Prieta (California) and 1999 Chi Chi (Taiwan) earthquakes for the ground motion analysis considering the magnitude of the earthquake, distance to the source, characteristics of the earthquake source (i.e. type of fault displacement), peak ground acceleration, local site geology, station type (i.e. free-field or small structure stations), and spectral content that was similar to the period range of interest. Following ASCE’s Guideline Document 7-05, a site-specific horizontal acceleration response spectra (ARS) was developed for the maximum credible earthquake (MCE) associated with the site.

Jan 1, 2018

By Miklós Kovács

A new type of the cast in situ piles is introduced. The installation of the new pile is based on a pushing in/gaining back procedure. A temporarily closed tip element with square shaped cross-section being attached to an upper circular shaft tube is vibrated into the soil. The steel armature is embedded. Concrete is poured into the tube and, the whole structure is gained back while the tip is in opened position. The width of the tip is less than or equal to 40 cm. The maximum length of the pile is about of 14 m. Great bearing capacity is resulted from the double soil compaction effect. No spoil is generated and, the pile construction can be controlled. The paper presents the results of four loading test at three sites with some soil data.

Jan 1, 2002

By Gustavo Armijo

Slippery and unstable working platforms spoiled not only by natural weather conditions but also by the effects of the construction process (drilling mud, grout slurry) are among the main sources of hazards. Due to this fact a set of recommendations for execution and maintenance of working platforms are presented in this paper, which is based on a study on this subject that is being carried out by AETESS, the Spanish Federation of Geotechnical Contractors. The main objective of this paper is to establish the basis for the right execution and maintenance of working platforms for geotechnical jobs with the idea of increasing safety and productivity. All the aspects involved in working platform safety are analyzed: ground and equipment characteristics, geometric conditions and working platform maintenance. From this analysis a set of general requirements is proposed together with the necessary specific controls before and after the equipment arrival to the job site. In order to facilitate this analysis some flow charts and tables and specific appendixes for each geotechnical technique are included.

Jan 1, 2006

By Daniel J. Rider

In 1980 the Niagara Frontier Transportation Authority contracted for three miles of cut and cover box structure and station construction in Main Street, Buffalo, New York. Project depths ranged from 30 feet to 60 feet below street grade. Soils, Figure No. 1, consisted of loose to very compact sands and gravels. Ground water level was generally 20 feet below grade. Specifications required a soldier pile and timber lagging support system with external dewatering. Soldier piles were to be installed in prebored holes with bentonite slurry and lean concrete backfill. Conventional pile driving was not allowed due to concerns over excessive noise and vibrations and its effect on nearby historic structures and the surrounding population

Jan 1, 1987

By Patrick P. A. Wolfs

In the summer of 2000, the ECR®/EFT® was first introduced in the Netherlands. After the first project a field test was performed together with other geophysical methods to prove the liability of these systems and their application in areas with soft soil and high groundwater levels. The objective of this test, which was carried out with three leakage detection systems, was to locate the holes. After this test several projects have been carried out. In this article the Dutch projects "Ringvaart Aqueduct" and "Bottleneck Limburg N296/N297" are mentioned.

Jan 1, 2006

By J. L. Goen

The Saint Joseph Hospital of Bellingham is located on a site underlain by glacial outwash. The construction of a five-story tower addition above an existing two-story wing was supported by five large trusses that impose a 1600 kips (7117 kN) column load on five pile caps in the courtyard of the hospital and on the new pile caps inside the existing MRI laboratory. The exterior columns of the trusses and the new parking garage addition were supported on conventional auger cast piles installed with conventional equipment. Helical Pulldown® micropiles were selected for use in the courtyard and the MRI laboratory because lightweight installation equipment (maximum unit weight of 7.5 kips (33.3 kN)) had to be used and it was required that no spoils be produced. The installation equipment was lifted into the courtyard by the jobsite crane. Sixty Helical Pulldown micropiles were installed for the pile caps in the courtyard. The pile caps inside the hospital were supported on 240 Helical Pulldown micropiles. Initial compression test indicated an allowable load for the micropiles to be 55 kips (244 kN). However, retest at a later date resulted in an increased allowed design load to be 85 kips (378kN) reducing the number of micropiles required by more than fifteen percent.

Jan 1, 2004

By M. Melih Demirkan, Juan J. Gutierrez, Raghav Ramanathan

"As the capital of the United Arab Emirates (UAE), Abu Dhabi is one of the world’s fastest-developing cities. To sustain its significant growth rate, Abu Dhabi must surmount challenging engineering problems in the most efficient manner. One of the challenges facing Abu Dhabi is ground settlement caused by poor groundwater control practices in inherently difficult subsurface conditions. For construction projects in Abu Dhabi located near the Arabian Gulf, groundwater is frequently encountered and must be accounted for and addressed during design and construction. Abu Dhabi City CenterRecently, the Abu Dhabi government developed a geodatabase by digitizing, processing and qualifying an extensive amount of existing information (i.e., more than 26,000 borehole logs). Because of the evaluation and processing of the geodatabase, detailed maps of geotechnical and hydrogeological surface features were generated using 3D modeling. Ultimately, the geodatabase was used to develop risk maps indicating geohazards, such as sabhka (or salt flats), uncontrolled fill and cavities. This information identifies the location and extent of the areas vulnerable to surface subsidence. Dewatering can change pore water pressure, which, in turn, alters the effective vertical stress in a soil mass and can affect groundwater chemistry. Changes in pore water pressure and groundwater chemistry can significantly affect soil and rock. The potential effects of dewatering include:• Change in effective stresses and shear strengths in soils• Increase in seepage velocities and pressures• Erosion or transport of soil particles and piping• Settlement• Collapse of subsurface cavities or voids• Transport of groundwater containing contaminants• Dissolution of soluble materials, such as rock salt or gypsum"

Jan 1, 2017

By George C. Webb

A wide variety and variable depth (up to 40 ft.) of compressible, uncontrolled fill (including construction debris and a perched water condition) was present at a proposed Kroger construction site in Dent, Ohio. An innovative solution using a combination of an ACIP foundation system with a Tensar geogrid reinforced load distribution platform was used to provide a high quality building pad. This system allowed the use of conventional shallow foundations for structure support. This system was used in lieu of more costly solutions, such as complete undercutting of the entire existing fill and replacement with engineered fill or a deep foundation/ structural slab system. The selected ground modification included a system of augercast piles bearing on shale bedrock, which were installed on a grid pattern over the entire building footprint. Then, three layers of Tensar polyproplene biaxial geogrid were used to create a reinforced soil mat, which was supported on the augercast piles. An eight-foot blanket of engineered fill was placed above the geogrid-reinforced mattress fill to establish the building subgrade elevation. Standard shallow footings and slab-on-grade construction methods were then used to support the 26-ft. tall masonry block building. A small-scale instrumentation program included monitoring the geogrid reinforced mat settlement, geogrid strain and earth pressure distribution under the reinforced mat to evaluate design assumptions and theoretical analyses. This case history describes the first application of a pile supported geogrid reinforced mat for structure support which has been documented in the United States.

Jan 1, 2003

Jan 1, 1993

By George C. Webb

A wide variety and variable depth (up to 40 ft.) of compressible, uncontrolled fill (including construction debris and a perched water condition) was present at a proposed Kroger construction site in Dent, Ohio. An innovative solution using a combination of an ACIP foundation system with a Tensar geogrid reinforced load distribution platform was used to provide a high quality building pad. This system allowed the use of conventional shallow foundations for structure support. This system was used in lieu of more costly solutions, such as complete undercutting of the entire existing fill and replacement with engineered fill or a deep foundation/ structural slab system. The selected ground modification included a system of augercast piles bearing on shale bedrock, which were installed on a grid pattern over the entire building footprint. Then, three layers of Tensar polypropylene biaxial geogrid were used to create a reinforced soil mat, which was supported on the augercast piles. An eight-foot blanket of engineered fill was placed above the geogrid-reinforced mattress fill to establish the building subgrade elevation. Standard shallow footings and slab-on-grade construction methods were then used to support the 26-ft. tall masonry block building. A small-scale instrumentation program included monitoring the geogrid reinforced mat settlement, geogrid strain and earth pressure distribution under the reinforced mat to evaluate design assumptions and theoretical analyses. This case history describes the first application of a pile supported geogrid reinforced mat for structure support which has been documented in the United States.

Jan 1, 2005

By R. J. Yan

There was a plant equipped with a 32000t Hydraulic Press to be built, under which a box foundation of 22.5m x 15m x 14.25m (depth) with a base slab of, varying thickness was proposed. The subgrade reactions, bending moments and settlements needed to be determined by means of in-situ model test. A model of the same materials as the prototype scaled to l/10 was embedded in-situ with simulated depth in the bedrock. A lot of data obtained from 39 bench marks, 32 elongation measuring points, 30 couples of electric resistance strain gauges and 24 pressure cells attached to the model foundation enables all the quantities required to be found out. Since it was put into operation, the settlements measured has reasonably agreed with the test results and the foundation has been in good condition.

Jan 1, 2010

By Don Deardorff, Ke Yang, Yingcai Han, Ken Sorensen, Robert Kruger, Mark Petersen, Diane Fiorelli, Larry Goldfarb, Kathryn Petek, Kwabena Ofori-Awuah

Design of deep foundations for lateral loads requires an understanding of soil-foundation-structure response during loading. Lateral loads on a deep foundation (piles) could be due to earthquakes, winds, waves, and/or machine vibrations. Over the years, analysis of response of piles due to lateral loads evolved from closed-form solutions to p-y methods to strain wedge to finite element/finite difference modeling. Although analysis of lateral response of piles and shafts is routinely performed, there is no single guidance document and/or standard for design and testing. Several different analytical methods are available for the analysis, and the resulting design can result in significantly different responses which can create confusion. This is especially true for analyzing and designing piles in potentially liquefiable soils with lateral spread issues under seismic conditions.This guidance document is intended to assist geotechnical engineers, pile designers, and contractors in analysis, design, and testing of piles and drilled shafts for lateral loads. This document discusses the background of different analytical and testing procedures and presents the recommended methods for analysis, design and testing of piles for lateral loads.Chapter 1 defines the different kinds of lateral loads to which a single pile or pile group may be subjected. This first chapter also presents different types of piles used to resist lateral loads.Chapter 2 discusses geotechnical issues related to lateral pile design such as liquefaction and lateral spreading and other non-seismic issues. Also addressed in Chapter 2 is geotechnical site characterization (as related to lateral loads) in terms of site investigation, in-situ testing, geophysical testing, laboratory testing, and estimation of soil/rock properties.Chapter 3 discusses the background and available analytical methods and tools for the analysis and design of single piles and drilled shafts. Several methods of analyses from closed-form elastic solutions to the finite element/finite difference solutions and their applicability are discussed. Available commercial computer software packages for analyzing single piles and drilled shafts are also presented.Chapter 4 expands the discussion of single piles and drilled shafts into the analysis and design of pile groups. In addition, group effects, resistance of pile caps, results of previous experimental and analytical studies, and available analysis tools and software for pile groups are discussed.Chapter 5 presents the issue of lateral resistance of piles and drilled shafts as discussed in different national and international building and non-building codes. A summary of extensive research on several codes are presented to facilitate the compliance with different codes.Chapter 6 discusses structural design issues of individual piles and drilled shafts such as depth of fixity.Chapter 7 discusses soil structure interaction issues related to kinematic and inertial effects due to seismic loading and available methods of analyses.Chapter 8 discusses and presents the typical procedures for the lateral load testing of piles. This guideline was developed as an aid to the practicing engineer in providing information, direction and commentary on the lateral design of deep foundations. Although all reasonable effort has been made to accurately compile the material and information contained herein, no warranty is made with regard to any such material or information and the Deep Foundation Institute assumes no responsibility for any possible errors or any direct or indirect result of the use of any such material or information. It is not intended that this document address every factor affecting lateral design for every situation. Therefore it is the responsibility of the person utilizing information from this document to confirm that it is appropriate and correct for their situation as well as to understand and properly apply

Jan 1, 2012

By Wei Zheng

A pulverized coal fired power plant is being built in Osceola, Arkansas, along the Mississippi River. The subsurface soil conditions consist of a certain amount of very soft clayey silt and clay underlain with a medium dense sand layer and a dense sand layer. The site has been raised four to five feet with fill material consisting of sand and gravel. Consolidation settlement due to the fill is expected to cause negative shaft resistance (downdrag) on the pile foundations. The site is located in a high seismic hazard area - the New Madrid Seismic Zone (NMSZ). The liquefaction analyses indicated that there is a high liquefaction potential in the medium dense sand layer. Load tests are needed to determine the shaft resistance and the end bearing of each soil layer for design purpose. Two types of pile foundations ? augered pressure grouted displacement pile (APGD) and partial augered pressure grouted displacement pile (P-APGD) were considered for this project. Ten pile load tests, including five compression tests and five tension tests, were performed for three different areas. Strain gauges were installed for the compression tests. The APGD and P-APGD piles were installed side by side for comparison. In addition, three additional dynamic tests were performed to supplement the information from the static load tests. Load deflection curves for the compression tests were predicted, and the failure loads were interpreted using four different methods. The shaft resistance and the end bearing were determined from the strain gauge data and were used to back calculate the ultimate capacity. The back-calculated capacities are in good agreement with the predicted failure loads; they were further verified with the tension load test results.

Jan 1, 2007

By Andrew McNamara, Stuart Norman, Matthew Dearing, Michael Pelken, Asha Panchal

The deep foundations industry has largely remained unchanged since in the advent of CFA piling in the 1960s. Piles have consequently been designed and constructed following the traditional codes and standards without much regard for optimising in-life efficiency or end-of-life reuse. After existing developments have been demolished there is little motivation to reuse existing piled foundations as their load bearing capacity and structural integrity cannot be verified. Therefore piling contractors are increasingly spending more resources on coring through existing piles, only to be replaced with larger diameter or deeper piles. The hollow element of the HIPER® Pile provides access to the entire length of the pile to permit inspections and a shaft in which the pile can be extended if needed. This paper presents and compares the embodied carbon savings, both during construction and through foundation reuse, from a HIPER® Pile scheme compared with the traditional solid pile scheme. A discussion on the benefits of this technology and its implications on warranties and approvals is also presented to motivate the foundations industry to embrace whole lifecycle assessments and support the journey to net-zero carbon.

May 1, 2022

By Christopher J. Ramsey, Don W. Dotson

"An existing four lane section of US 27 was widened to eight lanes. The project lies in the rugged Valley and Ridge Province of the Appalachian mountains starting at the Tennessee River in Chattanooga, Tennessee and extending 2.6 km north to Signal Mountain Boulevard. This terrain presented many challenges to accommodate the road widening in the narrow, rugged topography. Multiple tiered wall systems consisting of large tieback walls, post-tensioned reaction blocks, and gravity MSE walls for a total of approximately 30 retaining walls were required. The retaining walls served to stabilize the thrust faulted geology while also minimizing right-of-way acquisitions. The cut walls consist mainly of a tiered system of tied-back soldier piles walls with cast-in-place concrete facing. Cast-in-place pile shear walls were required along the toe of existing MSE walls to maintain stability during construction. This paper discusses the design methodology, which includes a hybrid (rather than traditional) earth pressure diagram intended to reduce life-cycle maintenance and long-term performance. Further this paper addresses wall construction, slope stability analysis, landslide mitigation alternatives, soldier pile wall design features, site challenges, monitoring and performance (to date) of the wall systems.INTRODUCTIONThis project involves the proposed widening of US Highway 27 (State Route 29) from the north end of the Tennessee River Bridge at Manufacturer’s Road to State Route 8 (Signal Mountain Road), approximately 2.64 km of roadway (Fig. 1). The project site is located adjacent to the Tennessee River on the north side of downtown Chattanooga, Tennessee in Hamilton County. The existing, limited access highway is to be widened from four lanes (two northbound and two southbound) to a minimum of eight lanes. Some portions of the alignment will expand to as much as ten lanes where northbound and southbound ramp acceleration/deceleration lanes coincide.In addition to the number and heights of cuts and fills involved, a major factor in determining an economical design for the alignment is the complicated geologic conditions along the roadway alignment. The existing roadway is situated between several steep cut slopes, some of which are only marginally stable or currently exhibit signs of instability. Due to the proximity of the project to the downtown area, the steep slopes along the alignment, and the relatively dense population near the alignment, widening the pavement and constructing cut and fill slopes to a stable configuration would result in major land acquisition for slope right-of-way."

Jan 1, 2015

By Luo Yang

A one-dimensional wave equation based algorithm for estimation of shaft and toe resistance of driven piles using High Strain Testing (HST) data is presented. The pile is represented by a uniform elastic bar, while the soil around the pile is assumed as a homogenized isotropic medium, and Smith model is adopted to represent soil-pile interaction in the wave equation analysis. In most cases, the displacement of pile particles along pile shaft is greater than recoverable soil deformation (i.e., soil quake in Smith model). Therefore, static shaft resistance could be reasonably assumed to be totally mobilized during pile driving. Smith damping factor is used to account for combined dynamic and rate effect. Force and velocity time histories measured at the pile head are used as input boundary conditions in an analytical solution of the one-dimensional wave equation. As a result, two unknown parameters, static shaft resistance and Smith damping factor, can be incorporated into the one-dimensional wave equation and determined analytically for the time duration prior to the first downward wave reaching the pile toe. Then, soil resistance and Smith damping factor at pile toe can be further determined. The advantage of the proposed analysis technique is that the Smith damping factor and the static soil resistance can be directly determined based on the closed-form solution of the one-dimensional wave equation, which is computationally efficient. Numerical examples are given to illustrate the use of the proposed method to determine the pertinent Smith model constants and the static resistances.

Jan 1, 2006

By Joanna Bzówka

Nowadays, there are some new requirements for the supermarket floors. The floors are loaded by high point- and moving-loads. In spite of this fact, it is necessary to ensure the stiffness of the floor and the stiffness of its support. When pile foundations are designed in the case of weak soil, the piles are recommended under the foundations of the supermarket and also under the floor layers. The example of foundation of a typical supermarket located on long­standing municipal dumping ground is presented. Indirect foundation - CFA piles, 0.5 m in diameter and 4.5 to 20.0 m long, was de­signed. Fifteen trial loading tests were carried out.

Jan 1, 2006

By Sandeep Pattnaik

Spring stiffness of soil and rock at different depth is often required for a pile structural model. If the pile is rested in multiple layers of soil, then it is rather more complex to simulate the soil in a structural model. The spring stiffness will vary based on density of soil strata over the depth. When a pile is socketed in weathered rock followed by a soil layer, a sudden change in subgrade modulus can influence the pile deflection drastically. Determination of soil spring and simulation of the pile in this condition required correct interpretation of subgrade modulus. The conventional approach of pile spring calculation underestimates the spring stiffness by ignoring underlaying stiffer layers. A finite difference method (FDM) of analysis can reasonably estimate the p-y of soil / rock based on subgrade modulus of each layer. However, the transition between the layers can be better simulated as per the deflection pattern of the pile. The lateral deflection of the pile is mainly dependent on the stiffness of soil layer surrounded by the pile. Generally, the lateral influence of a pile varies from 4D to 6D depending on the soil type. Therefore, soil spring stiffness around the pile would require special attention of a Geotechnical engineer to avoid uncertainty in the prediction of pile behaviour. In this paper, emphasis has been given to develop an approach for pile spring stiffness design. A standard software program LPile has been used to develop p-y curves of soil and rock layers at different depths and then converted to soil/ rock springs over the depth. Modulus of Subgrade Reaction as given in IS 2911 (Part2) was also used to correlate the spring value for different type of soil. Obtained analytical results were compared with full scale field trial for lateral deflection of pile. A good agreement between these two approaches has been established. The effect of soil structure interaction in the structural model shall be simulated by assigning an equivalent vertical and horizontal soil spring, which is developed by Winkler’s soil spring approach. A simplified design principle for calculating the pile spring is discussed in this paper. This approach has been extensively used in Mumbai metro elevated line pile design.

Nov 1, 2022