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By Ali Ebrahimi, Jeremy M. Gasser, Cuneyt Gokmen, Paul J. Sabatini, Roneet Das, William Tanner, Amir Ahmadipur

There are safety concerns related to operation of heavy equipment over coal combustion residual (CCR) impoundments during construction of the impoundment closure programs. As part of a pilot study prior to a full-scale closure construction, an access pathway and working platform were designed and constructed to facilitate equipment access for construction of deep soil mixing (DSM) zones on the ash delta of a CCR impoundment. The access pathway and working platform was constructed using shallow mass mixing with cement at the CCR surface to address safety concerns related to the geotechnical behavior of CCR. This paper describes the data from the instrumentation system which was implemented to monitor the geotechnical performance of the CCR during the pilot study. The instrumentation system included monitoring of the ground movement, vibration, and porewater pressure within the ash delta of the CCR impoundment during a pre-construction load testing, equipment mobilization over the access pathway, and DSM column installation over the working platform. INTRODUCTION A deep soil mixing (DSM) pilot study was conducted at a coal combustion residual (CCR) surface impoundment to evaluate mix designs and construction techniques for the regulatory closure. The DSM columns will create a wall which will separate and retain the CCR in a consolidated footprint separate from the closure by removal portion of the footprint and provide a barrier between the two areas of the surface impoundment. Historically, the surface impoundment received CCRs including fly ash, bottom ash, boiler slag, and gypsum, along with other byproducts produced from flue gas desulfurization (FGD). The predominant CCR in this impoundment were fly ash and bottom ash. The primary goals of the DSM pilot study were to assess the mix design strengths and to evaluate DSM construction techniques that could reach the design mixing depths of up to 90 ft. The DSM test columns were installed on the CCR delta approximately 500 ft from the nearest impoundment dikes. Another objective of the pilot study was to develop, construct, and monitor an access pathway for safe passage and movement of construction equipment on the CCR delta.

Jan 1, 2019

By Liiban A. Affi

The most difficult task of designing multilevel tieback walls for deep excavation support is the determination of lateral stresses. These lateral stresses act not only on the shored height, but also on the embedded portion of the soldier pile, all the way down to the pile tip. Examples of lateral stresses include uniform surcharge load (soil spoils or equipment), strip load surcharge from Cooper E80 (train loads), line load surcharge (exterior footing or retaining walls), and point loads (cell tower). In this paper we will discuss the various surcharges, do step by step example calculations and show how to take the total lateral stress output and present the design pressures for direct use by the substructural designer. Included is a case study from a project Anaheim Hills, California, USA.

Jan 1, 2010

By James S. Graham

Specifications for treated round wood piling are presented for the engineers consideration. Included in the text are background information, technical committees, Chellis, quality, treatment, static and dynamic stresses, accessories, and existing codes and standards. The specifications are also available using Word Perfect on 3.5 or 5.25 inch size disks provided by the National Timber Piling Council. Note: DFI recommended wording is wood, head, and toe, instead of timber, butt, and tip.

Jan 1, 1992

By Kirty Dave

Foundations in any contract are the most uncertain parts of the contract and most of the "Construction-Contract-Disputes" are either directly related to foundations or arise as 'Side-effects of changes in promises related to foundations. Foundation Engineering is defined as ' The art of selection, designing and constructing the elements that transfer the weight of structure to the underlying Soil or Rock." (Ralph B. Perk). This art started becoming a science since 1920, when scientific efforts to determine the behaviour of sub-surface materials were made. The art and science merged to give new techniques and the science started dominating the field as more and more refinement came in techniques to predict more accurately the characteristics of the sub-surface elements. Inspite of good thorough investigations and design, the contractual promises drafted could leave some room for differences between the parties and above all the prudency expected of both the parties may fall short of the expectations raised in the contract. This may give rise to disputes which may need to be resolved as per principles of law. This paper attempts to initiate a dialogue amongst Foundations-Engineers and Contractors as to how do we minimise the differences arising out of or related to contracts concerning "Foundations".

Jan 1, 1996

By R. D. Short

Environmental regulations for noise and air pollution are directly affecting the type of equipment and construction techniques being utilized for pile driving construction using diesel hammers in California and elsewhere. Consequently, the cost of construction is increasing and in some cases, the use of diesel pile hammers has been prohibited. Based on the trend in California and elsewhere in the world, environmental constraints are spreading and becoming more restrictive. The City of Tokyo, Japan, for example has banned the use of diesel hammers. Environmental restrictions on diesel hammers can be satisfied by using modern hammers, clean burning fuels, synthetic lubricants and pre-excavation techniques.

Jan 1, 1989

By Peter Jackson

The dewatering of the large construction pits required for major infrastructure projects often has a significant impact on the environment. This is particularly so in urban areas and where groundwater resources are of interest. These environmental impacts are inter alia, groundwater lowering and the consequent effects such as settlement and deterioration of timber foundations, together with the impact of the dewatering on the groundwater quality. In order to minimise the environmental impact of the dewatering, the quantity of water to be abstracted and the amount of groundwater lowering in the surrounding area must be minimised. This paper describes the measures that have been taken on the Copenhagen metro project to achieve the objective of minimal environmental impact whilst still carrying out a major dewatering scheme.

Jan 1, 2000

By Magued G. Iskander

The deterioration of concrete, steel, and timber is a serious hindrance to construction in marine and corrosive environments. Composite materials such as fiber-reinforced polymers (FRP) can offer performance advantages for construction in these environments. In the last decade, piling made of FRP composites has been used experimentally throughout North America. However, composites face obstacles because they do not have a long track-record of use in civil engineering structures. A comprehensive review of the current experience in research, testing, design, and practice of composite piling is presented in this paper.

Jan 1, 2002

By Chandramohan P. V

A unique tension pile where the pull is at a point a certain distance below the top of the pile. The pull is transferred by a cable consisting of high tensile strands. The HDPE duct of the cable prevents bond between the strands and pile concrete in upper portion. While soil friction on the pile will act downwards on the whole length, there is tension in the bottom portion of pile, there will be compression at the top portion.

Nov 1, 2022

By Adrian Mercer, Ashkan Ameri

Due to general degradation, increased traffic levels, and historical ground movement, this road and rail bridge which provides an essential link between the interior of the country and the Port of Abidjan, required significant repair and reinforcement. This included strengthening the pre-stressed concrete box girders and replacement of the existing bored pile foundations. Replacement piles had to be adjacent to, and no longer than, the existing piles, in order to not compromise the stability of the operational bridge during the works. The underlying geology, however, meant that the pile loads had to be predominantly transferred into the ground through end bearing. Rather than installing a greater number of piles or larger diameter piles, innovative thinking changed the usual mind-set of designing the piles to the prevailing ground conditions, to designing the ground conditions to suit the piles. Jet grouted columns were installed beneath the toes of the new piles to increase the bearing capacity of the ground. This significantly contributed to the sustainability of the project and reduced carbon emissions through saving concrete, steel, plus transportation and disposal of spoil.

Sep 8, 2021

By James Warner

Although use of low mobility grout is just now beginning in some parts of the world, its advantage for many applications has been well established through more than 50 years of positive experience. The single largest area of application continues to be densification of soil by way of compaction grouting. Because it is often the safest and least costly method for soil improvement in general, and virtually always that in connection with soil improvement under, or adjacent to structures or in developed areas, use will undoubtedly increase both geographically and in diversity of application.

Feb 10, 2003

By Rick Deschamps

The Block 76 project includes the demolition and redevelopment of an entire city block for mixed use retail, office and residential properties directly adjacent to Historic Temple Square in Salt Lake City, Utah. Excavation was carried out 65 ft below street grade and by as much as 50 ft directly below adjacent buildings supported by shallow foundations. Movements of the earth retention system and adjacent buildings were monitored in real time using automated equipment which complemented traditional geotechnical instrumentation. In the areas immediately adjacent to the existing buildings 9 stories or greater, anchored diaphragm walls were employed. Areas of the site not supported by diaphragm walls employed a soil nail wall system. Jet grouting was used for water cutoff in lieu of dewatering along the north and east sides of project. In total, the earth retention scope included 45,000 sq. ft of diaphragm wall, 104,000 sq. ft of soil nail wall, and micropile underpinning of 3 buildings. This paper provides an overall description of the Block 76 project. A detailed account is provided of the technical and commercial lessons learned. The project provided a unique example of how an owner can receive best overall value by acceptance of some technical risk up front. Benefit was gained by allowing the contractor to reduce contingencies within the bid from unknowns on a fast-track project.

Jan 1, 2009

By James P. Hambleton, Sam A. Stanier

A perceived advantage of screw-type foundations is the ability infer aspects of foundation performance from quantities measured or observed during installation, especially the installation torque. A particular concept widely used in practice is to correlate installation torque to ultimate capacity. This notion has proven useful as a field verification technique despite the absence of validated models that relate key variables of interest, such as installation torque, axial (crowd) force, geometrical parameters, and soil strength. This paper considers previous work by the co-authors and collaborators on analytical, numerical, and physical modelling of screw piles to relate the quantities measured or controlled during installation (e.g., installation torque) to the ultimate capacity and soil strength. Attention is given to saturated clay as a particular soil type amenable to simplified analysis. An analytical model for a single-helix pile is considered as a means of directly relating the ultimate capacity and undrained shear strength to the installation torque, crowd force, plate pitch, plate diameter, shaft diameter, installation depth, and surface roughness. The connection between the installation variables and ultimate capacity—and the sensitivity to crowd force in particular, a quantity that is typically not measured during field installations—is also discussed. The theoretical predictions are compared against data obtained from small-scale laboratory experiments that suggest the installation torque relates to the remolded strength of the soil. INTRODUCTION Screw piles are deep foundations that are twisted into the ground through an applied torque. Advantages over driven piles or drilled foundations include the relative silence of the installation, with low ground vibrations, and the possibility of being easily decommissioned by reversing the direction of twisting. Screw piles are now routinely encountered as a flexible, low-cost solution for numerous applications (Figs. 1 and 2), and they are also being considered for applications in offshore energy production due to limitations being imposed with respect to decommissioning and underwater noise. Also known as “screw anchors,” “helical piles”, or “helical anchors,” screw piles consist of helices or helical plate elements attached to a central shaft. Figure 3a shows the components of a single-helix pile and key variables. The diameters of the shaft and helix are denoted by d and D, respectively, and p is the pitch of the helix. Variable H denotes depth of the helical plate, and T and N denote the torque and axial (crowd) force applied during installation. In typical applications, the pile includes multiple helical plates, and the shaft is composed of segments that allow for it to extend to large depths into the soil.

Jan 1, 2019

By Jeffrey A. Schaefer

The Olmsted Locks and Dam project is located on the Ohio River approximately 16.5 miles upstream of its confluence with the Mississippi River. It consists of twin 1200 ft. locks with floating and fixed approach walls, five 110 ft. wide tainter gate bays, a 1400 ft. wide navigable pass boat operated wicket gate section, and a 400-ft. section of fixed weir (Fig. 1). The project will have a total cost over 1.0 billion dollars, and as such is one of the largest civil works project underway in the Corps of Engineers.

Jan 1, 2001

By Xavier Pita, Alexandre Pinto, António Cristovão, Rui Tomásio

"The cutter soil mixing technology was been applied in Portugal since the last seven years. The aim of this paper is to present the main design and execution criteria, related with both the cofferdam and foundations solutions, using soil-cement panels, reinforced with steel profiles, at the new Leixões Cruise Terminal, located at the Leixões Port, in Portugal. The Terminal building was built with one basement on a marine environment, over very difficult geological and geotechnical conditions, which demanded the use of some unusual and integrated geotechnical solutions. It is also pointed out the importance of the QC/QA, as well as the technical, economic and environmental advantages of the cutter soil mixing technique, comparing with same more conventional solutions.1 INTRODUCTIONThe construction of the new Cruise Terminal at Leixões, main gate of the Atlantic Ocean to the North of Portugal and Spain, as a consequence to the constant increase of the cruise traffic, was a challenge from both the geotechnical and structural point of views, mainly due to very difficult and unusual conditions, ranging from the geological and geotechnical scenario to the existent and under operation Leixões Port infrastructures, mainly the South break water, as well as the existent cruising boarding deck (Figure 1).According to the Terminal Project it was necessary to build one basement below the water table level, including several earth retaining structures in order to allow the excavation works on dry conditions leading to a global cofferdam effect. For this purpose soil - cement panels, using CSM technology, reinforced with steel profiles, micropiles (both for foundation and cut off effect) and the existent sheet piles were used. Also pointed out are the adopted special foundations of a very complex structure, including bored piles and micropiles (Figure 1)."

Jan 1, 2015

By Lance Rasband, Richard Hanke

"Seattle Tunnel Partners (STP) started mining on Seattle’s SR99 tunnel on July 30, 2013, working slowly through a 15 ft (4.6 m) thick fiber-reinforced concrete headwall. Once through the headwall, the machine would move through roughly 400 lineal ft (122 m) of jet grout-improved soil at a rate slightly over 6 ft (1.8 m) per day. It was anticipated that once through the improved area, Bertha—the world’s largest tunnel boring machine—would move at a rate of 35 ft (10.7 m) per day. By the end of October 2013, Bertha had mined roughly 430 ft (131 m), averaging 4.73 ft (1.4 m) per day, and had begun mining within native soils. By the start of December 2013, tunneling reached the 800 ft (244 m) mark and Bertha averaged 12 ft (3.7 m) per day, achieving as much as 42 ft (12.8 m) of progress on some days. However, on December 6, 2013, Bertha began to stumble and all progress quickly came to a halt. Preliminary InvestigationInitial reports stated that an obstruction had stopped the machine in its tracks. Malcolm Drilling received an early morning call on Sunday, December 8, 2013, from STP to rapidly mobilize a Bauer BG-50 drill rig with crews to investigate what was hindering Bertha’s progress. Malcolm’s equipment and crews flew into action and were completely mobilized and operational by mid-week. The preliminary investigation involved installation of 10 deep dewatering wells to reduce the hydrostatic head within the ground around the machine and allow STP personnel to inspect the cutter head from within the shaft for presence of obstructions. By the close of December 2013, the wells were installed and the dewatering system was fully commissioned. STP crews were then able to inspect the cutter head and found small fragments of a steel pipe wrapped around the outside of the shield. The steel was apparently from an abandoned 10 in (0.25 m) diameter monitoring well casing previously installed by WSDOT (Washington State Department of Transportation) to monitor groundwater conditions for the design and planning of this very project. After the steel was cut out of the head and cleared from Bertha’s path, she attempted to move forward but was only able to manage a slow crawl"

Jan 1, 2015

By Sanjay Gupta, Sorabh Gupta, Ravi Sundaram

A geotechnical forensic evaluation of piles for an industrial facility in Haryana was performed to assess the quality of the piles and to evaluate piles installed using two different types of rigs. Low strain pile integrity tests were performed on all piles to assess the pile length and possible presence of structural defects. Coring was done through questionable piles for the clinching evidence of concrete quality and pile length. Probe holes adjoining piles helped confirm the bulging of piles at shallow depth. The paper highlights the importance of implementing a well-planned quality assurance program to confirm that all piles installed are of the desired quality.

Sep 1, 2022

By Stefan Larsson, Sadek Baker, Razvan Ignat

"This paper describes the execution of two full-scale field tests where a braced steel sheet pile wall interacting with rows of overlapping dry deep mixing columns was first excavated and then loaded to failure. The aim of the tests is to provide insight of the performance of dry deep mixing column rows located in passive zone and interacting with a retaining structure. The column rows were installed perpendicular to the sheet pile walls with two different area ratios, i.e. different distanced between the column rows. Both tests were extensively instrumented with inclinometers, pore pressure transducers, bellow-hoses, earth pressure gauges and strain gauges mounted on the struts. Results of the performedtests will serve as development of design methods for excavation support with columns.INTRODUCTIONDry deep mixing has been used with good results to strengthen the soil when excavations are to be performed in locations with thick soft clay deposits. An application that has increased in recent years is to install columns on the passive side of the retaining structure. Columns can be installed in different patterns but rows, grids or blocks are the most common arrangement. The use of column type ground improvement installed on the passive side of a retaining structure has been documented for a few field cases, Tanaka (1993), O’Rourke et al. (1997b), O’Rourke and McGinn (2006), Ou et al. (2008). By improving the soil on the passive zone, the passive earth pressure in front of the retaining structure is increased. This has proven to reduce the excavation induced deflections behind the retaining structure, reduce the structural forces (bending moment in the retaining structure, strut and anchor forces) and improve the safety against basal heave failure. The main focus of the conducted measurements within these cases has been on recording deflections and structural forces on the retaining structure and there is very little documentation available of the stress-strain behavior of the improved soil acting on the passive side of the retaining structure.Two full-scale tests of braced steel sheet pile walls interacting with rows of overlapping dry deep mixing columns were first excavated and then loaded to failure was conducted during the spring-summer of 2014. This paper briefly describes the test set up, instrumentation, test procedure and some selected results from one of the conducted tests."

Jan 1, 2015

By John P. Davis

The use of conventional, circulatory air rotary and fluid rotary, cased and uncased drilling methods in the vicinity of sensitive infrastructure can have deleterious effects on the ground conditions surrounding and supporting structures and the structure itself. Furthermore, the use of these conventional methods offers the engineer or contractor little information about the condition of the subsurface during geotechnical applications. Conversely, sonic drilling measurements and samples can be used to evaluate actual conditions during the progress of exploration and construction across a given site. This paper will discuss the history and properties of sonic drilling and explore case histories of geotechnical applications for the advancement of boreholes within vulnerable structures and on sensitive sites for several recent infrastructure projects ? a tunnel and railroad project, a dam grout curtain project, a bridge micropile exploration project and a tunnel instrumentation project. Project summaries will discuss the advantages realized when the application of sonic drilling techniques demonstrated superior accuracy, quality control, efficiency, productivity, penetrability, waste minimization and adaptability when drilling adjacent to or within existing infrastructure. Finally, the discussion will address the current testing and application of sonic drilling to the installation of micropiles, earth retention anchors, grout injection and instrumentation installation where the quality control benefits provided by the inherent soil cores, measurement while drilling systems, accuracy and non-destructive production drilling features will be advantageous.

Jan 1, 2006

By Jogeshwar P. Singh, Aser I. Abbas, Mohamed Ashour

The presented methodology predicts the pile head response (i.e. pile head load - displacement curve) and develops the load transfer (t-z) curve of piles in sandy soils under tension forces based on soil/pile properties and soil-pile interaction. The proposed approach improves the prediction of the t-z curve in sandy soils compared to current practice. The method employs a nonlinear soil constitutive model to calculate the mobilized shear stress/strain in soil at the soil-pile interface induced by pile upward displacement. The approach accounts for the influence of the pile slenderness ratio on the predicted t-z curve and is validated through comparisons with measured pile head response and t-z curves from full-scale pile load tests. INTRODUCTION Piles may be subjected to axial uplift forces due to either static loading or cyclic loading. The majority of methods are only concerned with the pile ultimate tensile capacity. However, the mobilized pile stiffness (i.e., pile-head load-displacement relationship) is essential to determine the interaction between the foundation and the superstructure and consequently the performance of the whole structure. Methods that assess the pile ultimate tensile capacity usually assume the failure surface at the soil-pile interface and estimate the local side shear resistance using a lateral earth pressure approach. The Naval Facilities Engineering Command (NAVFAC 1986) and the US Army Corps of Engineers (USACE 1991) employed Eq. 1 to assess the ultimate shear stress (τ) developed at the soil-pile interface.

Jan 1, 2018

By Patrick Bermingham

The advancement of hydraulic impact hammers has followed the general advancement of hydraulics. The construction industry has been revolutionized by the application of hydraulics in excavators, cranes and, of course, in the hydraulic vibratory driver/extractor, which has become a standard tool. The innate ability to move a large mass with a very small displaced volume has given hydraulic power the advantage over previous power mediums. Recent development of more specialized and complex seal configurations and compounds has greatly improved the reliability and permitted the use of higher pressures in hydraulic systems.

Jan 1, 1987