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By Timothy C. Siegel

In response to a solicitation for ground improvement for the construction of a new hospital in Owensboro, Kentucky, the team of Berkel & Company Contractors and Dan Brown and Associates PC designed and installed lightly reinforced cast-in-place piles (known commercially as Cast-in place Ground improvement Elements or CGEs) as part of a composite ground system. The concept of the design is that the structure load is shared between the piles and the soil subgrade. The load sharing is controlled (to some degree) by the placement of a cushion between the pile head and the bottom of the overlying spread foundation. In an effort to confirm the design principles and to better understand the behavior of composite ground, the design-build team performed plate load tests on ground with a single CGE and with a group of CGEs. The small plate test (on ground with a single CGE) characterized the stiffness of the cushion. The large plate tests showed that the cushion will distribute the applied load to the CGEs and to the soil subgrade between the CGEs. On the basis of the plate tests, it was concluded that the plate stiffness can influence the test results. The use of a concrete layer was effective at supplementing the plate stiffness. The cushion was shown to be an important component of a composite ground system by allowing mobilization of the soil subgrade resistance and avoiding a stress concentration at the tops of the CGEs that would otherwise be present if the spread foundation and piles were rigidly connected. Because the composite ground system engages the resistance of the soil subgrade, the structural demand is reduced and consequently there is a potential for savings when compared to a conventional pile foundation. Several foundations for the new Owensboro hospital are being monitored for vertical movement during construction of the superstructure that will extend through 2011. At the time of this paper (mid 2011) the settlement of the foundations due to only part of the structural load (primarily the structural steel) has been negligible.

Jan 1, 2011

By Swaminathan Srinivasan, Jess A. Schroeder

"Landslide activity along U.S. 50 in Cincinnati, Ohio (USA) has caused roadway damage for decades. After a necessary closure of three lanes due to slope movements, emergency stabilization measures were undertaken to protect the roadway by providing a short-term solution necessitated by The Ohio Department of Transportation budget constraints. The landslide shear plane occurred on a sloping bedrock surface as much as 50 feet below grade. Drilled shafts were installed 40 feet downslope of the roadway shoulder and were heavily reinforced across the shear plane but steel reinforcing did not extend the full length of the shafts and was stopped well short of the ground surface. Instrumentation data has been collected for 11 years after construction has shown these “Stub Piers” have provided much more than a short-term solution and have provided an attractive alternate to conventional deep shafts or tieback drilled shaft options.INTRODUCTIONLandslide activity has occurred along U.S. Route 50 in western Cincinnati, Ohio for many decades. The site is located between North Bend and Addyston, Ohio on the right descending (cutting) bank of the Ohio River. Road distress caused by slope movements required periodic repairs over recent decades. Railroad tracks downslope of the roadway also showed signs of horizontal displacement and periodic repair. Visual evidence in 2005 suggested the shear plane extended below the US 50 roadway and extended out into the Ohio River.A weed and brush-covered slope extended down slope from the roadway at about 3H:1V for a vertical distance of about 20 feet. Above US 50, the hillside continued to rise more than 100 feet. There is a railroad right-of-way at the toe of the slope with the Ohio River bank just downslope of the railroad.In 2005, Terracon Consultants was retained by the Ohio Department of Transportation (ODOT) to perform a geotechnical study that included 17 test borings and inclinometer monitoring at 4 locations. Roadway damage was occurring (see Figure 1). After only a few weeks of monitoring, the inclinometer casings sheared off about 50 feet below grade, near the soil / bedrock interface (see Figure 2). Soon after, the roadway distress worsened, causing ODOT to close 3 of the 4 lanes to traffic and reroute traffic onto the remaining single lane and shoulder. Terracon was asked to develop a stabilization design under emergency repair conditions. However, both limited budget and time-related constraints necessitated a direction by ODOT that the solution be at least “pseudo” short-term (3 to 5 years)."

Jan 1, 2017

By Eiji Kojima

In this research, dynamic and static load tests were performed on permanent foundation piles which had a pile length of 30 m, 800 mm in outer diameter and 15 mm in wall thickness. In this site the dynamic horizontal load test on a smaller test pile, 12 m in length, 500 mm in outer diameter and 12 mm in wall thickness, was also carried out. The static horizontal load versus horizontal displacement derived from the dynamic load test conformed well to that measured in the conventional static horizontal load test of the pile with 800 mm diameter. Then an attempt was made to predict the horizontal load displacement of the pile with 800 mm diameter based on the results of the dynamic horizontal load test of the pile with smaller diameter of 500 mm.

Jan 1, 2006

By Kazuyuki Matsuzawa

A series of plate loading tests were carried out on a loam ground in order to investigate the influences of the plate size and the loading rate on the observed load-settlement relations. Two circular plates having diameters of 0.3 m and 1.0 m were used. Three types of loading methods were employed; 1) static cyclic maintained load test, 2) static continuous load test, and 3) rapid (dynamic) plate load test. An interpretation method called non-linear damping method was used to estimate a static load-settlement relation from the rapid plate load test signals. The derived static load-settlement relations match well with the measured results from the static load tests.

Jan 1, 2006

By Boleslaw A. Klosinski

Drilling of a pier hole is accompanied with stress releasing in the surrounding soil and often with loosening of soil at the pier base. In effect the drilled piers are more deformable than driven piles of comparable dimension. The bearing performance of a pier may be considerably improved by properly executed base grouting. Various techniques of base grouting are used; many of them were described by Bruce (1986). The grouting devices are often placed within the pier. Alternatively the soil at or under the base is treated by cement or chemical grout. Preloading of the base subsoil by use of a special grouting cell is considered as the most effective way. Treatment of the ground below pier base with cement or chemical grout may be also useful. It may be performed immediately after the pier construction or during service, as a measure for increasing the pier capacity.

Jan 1, 1995

By Loring A. Wyllie

Preparation, understanding and use of soils reports must be a team effort to be fully effective. The soils engineer must know what is to be built and exactly where. The structural engineer and owner must be fully informed on the foundation problems of the site. There must be frequent team review of information obtained from subsurface investigation and of design as details develop. The soils engineer should be available on a continuing team basis as design proceeds and should be directly involved with inspection and interpretation of site conditions as construction continues.

Jan 1, 1986

By Alexander B. Reeb, Richard J. Varuso, George M. Filz, Jehu B. Johnson

"T-walls, which are concrete floodwalls in an inverted “T” shape, are an integral component of the Greater New Orleans Hurricane and Storm Damage Risk Reduction System (HSDRRS). In order to resist large lateral flood loads, T-walls are typically supported on long batter piles that extend through the weak and compressible clays and peats commonly encountered in southern Louisiana. Since the piles are battered, settlement of the compressible foundation soils can result in loads acting normal to the piles and induce pile bending moments. Therefore, the design of pile-supported T-walls is a complex soil-structure interaction problem that requires detailed and careful numerical analysis to accurately estimate the stresses and bending moments in the piles. For this paper, numerical analyses were performed for three cross sections that each included a two-pile T wall system that was installed within a 15-ft tall new levee embankment. The cross sections were identical except that the elevation of the T-wall base was varied. This paper discusses the analyses, and it compares the influence of settlements and flood loading on the pile stresses and bending moments. In addition, this paper includes general recommendations for the analysis and design of pile-supported T-walls in practice.INTRODUCTION AND BACKGROUNDThe recently completed Greater New Orleans Hurricane and Storm Damage Risk Reduction System (HSDRRS) includes 350 miles of levees and floodwalls and is designed to defend against a 100-year storm surge event. The floodwalls predominantly consist of I-walls and T-walls. I-walls are comprised of a sheet pile wall curtain capped with a monolithic concrete wall above grade. T-walls are similar to I-walls, but they include a wide concrete base at grade, which forms an inverted “T” shape, and they are generally supported by long batter piles that provide additional lateral and rotational stability for resisting flood loads.During Hurricane Katrina, several I-walls failed, resulting in large breaches and devastating flooding (Duncan et al. 2008, IPET 2009). T-walls on the other hand performed quite well, including T-walls that were overtopped and eroded on the protected side, yet still did not collapse. As part of the HSDRSS, more conservative designs and height restrictions were required for I-walls (USACE 2011), and a number of I-wall sections were replaced with T-walls. However, the design of pile-supported T-walls is complex and requires careful consideration of both flood loading and settlements."

Jan 1, 2017

By Deshmukh A. M.

Existence of human beings and their relationship with the nature is symbiotic. The lack of perspective and negligence of nature disturbs the equilibrium of environment and causes unprecedented disasters. Geotechnical engineers are directly concerned with hazards of nature as elements of foundation and of nature are inter related. Rational design and construction of foundation can be accomplished only after properly assessing influence of environment This paper briefly delineates impacts of environment and human activities and presents salient features of management of impacts through the system of deep foundation. Limitation of negative effects and enhancement of positive developments necessitates eco-consistent planning of engineering projects based on the geotechnical aspects of environmental impact management.

Jan 1, 1996

By G. R. Dasari

New Austrian Tunnelling Method (NATM) has been analysed by Finite Element method in two and three dimensions by Strain Dependant Modified Cam Clay (SDMCC) Model. The effects of construction sequence, stiffness of shotcrete and time dependency of shotcrete on surface settlement magnitude due to the NATM have been studied. Settlements obtained in 2D analysis, as expected, found to be more than the observations. The surface settlements obtained in 3D analysis found to be about 3 times less than equivalent plane strain analysis. This is due to mobilisation of soil strength around the tunnel face and soil-tunnel lining interaction. About 40% settlements occurred due to excavation of face at the monitor section and 60% after the excavation crossed monitor the section.

Jan 1, 1996

By Scott D. Thomson

The client for this project specializes in the use of state-of-the-art technology to fabricate and assemble composites and metal-bonded structures for commercial and military aircraft programs. One of the key components for this operation at the client's plant is a highly precise computer-numerical-controlled router known as the Shoda Machine. This machine tool was installed at the plant in July 1998 for the manufacture and inspection of aircraft parts, and it is extremely sensitive to deflections. To monitor the occurrence of deflections, an internal laser system continuously checks the machine calibration. Deflections in excess of 5/1000-inch in the foundation on which the machine rests require costly periodic re-leveling and recalibration of this tool. Therefore, a significant problem arose when measured deflections during machine operation were as large as 20/1000-inch. In addition, the foundation was cracked in at least three places as a result of elastic foundation movement caused by dynamic loading as well as shrinkage and loss of base support. Deciding on a remediation procedure to alleviate or eliminate these problems involved the following important considerations: (1) achieving the client's need for reducing deflections to less than 5/1000-inch, (2) minimizing the repair cost as much as possible, and (3) reducing the time required for implementation of the foundation remediation solution. After evaluating the advantages and disadvantages of several alternatives, jet grouting was selected as the most suitable solution. The jet grouting program provided columnar elements of soilcrete to remediate the Shoda Machine foundation.

Jan 1, 2003

By Carole L. B. Mitchell

The increased use of micropiles and soil nailing presents a growing database of verification and sacrificial load test data. In Washington State, the use of micropiles is becoming common, and soil nails are now almost as widely used as tiebacks; yet the state of the practice in understanding load transfer rates has not improved. This research compiles load test data for micropiles and soil nails from Shannon & Wilson?s records in the Puget Sound region of Washington. Ultimate and maximum load transfer rates for design are correlated to geologic units and soil types found in the region. Variables such as pressure versus tremie grouting, hole diameter, soil density/consistency, and the presence of groundwater are compared to load transfer rates for similar geologic units and soil types. Results are also compared to published PTI, AASHTO, and FHWA guidelines. Our results indicate that published ranges may be conservative for some soil types in the Puget Sound region, especially for micropiles. Performing verification tests to failure instead of typical verification or performance tests is needed to improve correlations and provide less conservative design load transfer rates.

Jan 1, 2006

By M. J. Preim

Two case histories are presented on the evaluation of static bearing capacity of piles driven in soils that exhibit time dependent strength changes. Under consideration are a steel and a concrete pile driven into soils generally consisting of silty and clayey fine sand. Pile dynamic measurements and analyses were performed on both piles during initial installation, and also during restrike one week later. This information was used to predict each pile's long term capacity (defined as 14 days after initial drive), which was then compared to that measured with a static load test. Agreement between predicted and measured capacities were remarkably good, with an average error of only 4.5 percent. Two weeks after driving, total pile capacities were three times those at the end of drive. If only the skin friction was considered, however, it increased by an average factor of 16. The increase in pile capacity was determined to be linear over the time period considered.

Jan 1, 1989

By James E. Maccariella

Replacement of an existing movable bridge with a new low level fixed bridge would not accommodate potential future navigation traffic. In order to replace the existing bridge in a cost effective manner, while accommodating the potential future needs of the Port of Salem, a new bridge was proposed that would permit conversion to a vertical lift type movable bridge should a potential need for upstream navigation warrant such a project in the future. Drilled shafts were found to be the most desirable foundation type for the replacement of the Route 49 Bridge over Salem River. Their ability to resist scour, be constructed without cofferdams, adequately resist vessel collision forces, and accommodate conversion to a future vertical lift bridge allowed the project to meet both the needs of the New Jersey Department of Transportation and the Port of Salem.

Jan 1, 2005

By Camilla Favaretti, Benjamin Turner, Anne Lemnitzer

Pile foundations are extensively used in the construction of various types of superstructures, including tall buildings, bridges, freeways and offshore structures. A fully constrained tip embedment such as a rock-socket offers an attractive solution for achieving significant tip resistance and improving the load-carrying capability of the foundation element. In profiles with very soft surficial soil, rock-socketing often provides the only reliable source of axial and lateral resistance. In preparation of a large-scale testing program on rock-socketed piles at UC Irvine (UCI) geared towards studying the magnitude of shear amplification at the rock-soil boundary of pile foundations, a pre-test model-scale experiment was executed in the UCI Structural Laboratory. The objective of the model-scale experiment was to iterate and validate the test setup, study the influence of important boundary conditions, assess instrumentation techniques and sensor placement, and to gain preliminary insight into the small-scale specimen non- linearity. In addition, this model-scale study provides ample opportunity to compare lateral performance parameters with analytically predicted lateral load behavior using traditional soil resistance functions and limit state analyses and explore new techniques for the derivation of soil resistance functions. The pile specimen had a pile diameter (D) of 10 inches and a total pile length of 125 inches. The pile was embedded in a 40 inch simulated rock socket overlain by 52 inch of medium dense sand (DR~50%). The pile extended 32 inches above the soil surface, where cyclic lateral loading was applied. The pile was installed in a laminar metal frame box with inside dimensions of 39 inches in width (W), 73 inches in length (L) and 86.1 inches in height (H) as shown in Figure 1. During testing, the box was restrained using a rigid bracing system consisting of concrete reaction blocks, wooden braces and steel girders.

Jan 1, 2018

By Amalia Giannakou

This paper utilises 3-D finite-element modeling to study the static and dynamic lateral harmonic response of inclined piles, in a homogenous and a non-homogenous soil, modeled as a linear hysteretic medium. The results of a comprehensive parameter study are presented in the form of dimensionless plots of: (a) static and dynamic swaying and rocking stiffnesses and damping ratios, and (b) distribution of internal forces (bending moment, shear and axial force) with depth. These plots can be readily utilised in practical applications and they offer insight on the role of the inclination in the response of flexible piles.

Jan 1, 2006

By Pastsakom Kitiyodom

In order to estimate the deformation and load distribution of a single pile subjected to dynamic horizontal load as well as vertical load, a simplified method of three-dimensional numerical analysis, KWaveHybrid program, is developed using a hybrid model. In the hybrid model, the pile is modelled as elastic beams, and the soil at each pile node is treated as springs and dashpots in both vertical and horizontal directions. KWaveHybrid is also able to analyse the static response of the pile. Validity of the newly developed program is examined through comparisons with theoretical values and horizontal dynamic and static pile load test results

Jan 1, 2006

By Daniel L. Hanson

This paper presents a case history of the design, installation and performance of a tied-back tangent caisson retaining wall which was constructed as part of the Third Harbor Tunnel project currently underway in Boston, Massachusetts. The Third Harbor Tunnel project consists of a large multi-lane transportation tunnel which is being constructed by the sunken tube method. In this type of construction, the tunnel alignment, slopes and bedding are excavated and installed underwater and the tunnel sections floated over the proper alignment and sunk in place. The tangent caisson retaining wall discussed in this paper was constructed to provide support of the upper portions of the tunnel excavation at the East Boston Portal where the tunnel exited from below the harbor and continued underground on shore. A portion of the tangent caisson retaining wall was also utilized to provide earth support for the barge unloading facility where spoil from the tunnel excavation was transferred to surface vehicles for removal from the site. PROJECT BACKGROUND The tangent caisson retaining wall was constructed by The Millgard Corporation (TMC) as a subcontractor to the Boston Third Harbor Tunnel Contractors, a Joint Venture which consisted of the firms of Morrison-Knudsen Corporation, Interbeton Inc., and J.F. White Contracting Company. The entire project team is listed below on Table 1. The design of the tangent caisson wall system was performed by Hanson Engineering, P.C. (HE) acting as design consultant to TMC. The retaining wall system incorporated a single row of pressure injected earth anchors (tie-backs) as part of the design. The earth anchors were designed and installed by Drill Tech as a subcontractor to TMC.

Jan 1, 1994

By António A. Henriques, António Gomes Correia, Ana Teixeira

"Abstract Pile foundations are often used for important structures, and thus, reliability evaluation is an important aspect of the design. Reliability methods have become increasingly important as decision support tools in different areas. The main benefit of reliability analysis is that it provides quantitative information about the parameters (uncertainties) that most significantly influence the behaviour under study. In particular, the design of pile foundations still involves many limitations and uncertainties, particularly when there is not enough investment in soil characterisation and/or pile load tests. In addition to the uncertainties associated with soil characterisation, physical, statistical, spatial and human uncertainties exist. In this subject, the primary purpose of this paper is to demonstrate the application of reliability methods to geotechnical pile design (axial load). It also presents a simple and practical approach to performing it using Monte Carlo Simulations, intending to provide knowledge for code harmonisation and encouraging the development of such methodologies in geotechnical practice. Sensitivity analyses are shown to understand the influence of each uncertainty type coming from different sources. An application example indicates, corroborating other studies, that the model error is the most influent uncertainty. As such, when using the different models (SPT-, CPT- and PMT-based) for bearing capacity, the results emphasise the need for a well-defined and wellcharacterised resistance model, also these results allow the engineer to understand how important the load tests can be to achieve reliable results and economic designs.1 IntroductionUnlike the approach to reliability evaluation used in structural engineering, the traditional procedure used in geotechnical designs addresses uncertainties through high global or partial safety factors (SF), mostly based on past experience. However, this approach to addressing uncertainties does not provide a rational basis for understanding their influence on design.Furthermore, the new regulation codes and social concerns, such as the sustainability or the economy, are imposing geotechnical engineers to increase their ability to deal with uncertainty in a direct and more rational way. Designs should be economic, sustainable and reliable at the same time. Concerning the reliability part of design, different approaches can be done, but the most important thing to keep in mind is the simplicity and efficiency of the tools and applied methods."

Jan 1, 2014

By Liu Run, Jia Zhao-lin, Yan Shu-wang

"Piles with diameter larger than 2m in engineering can be defined as large diameter pile, and piles used for oil platform foundation in Bohai Gulf, are usually over 100m long and 2m in diameter. Such long piles have to be manufactured by segments before installation, because of transformation and hoisting difficulties. The segments of the pile are assembled by welding during installation one to another. Normally, assembling two pile segments takes one day or even a longer time, which mainly depends on construction conditions. After pile segment assembling, it proves to be difficult to restart the successive penetration. The mechanism of pile refusal is discussed and the process of driving a segmented pile is simulated with a finite element program. The calculating results show that, when the stick-up stability was satisfied, increasing the length of the last segment of the pile and assembling the pile segments when the pile tip penetrates into a clay layer could greatly ease the difficulty of driving the pile. Furthermore, cutting down the pile extension time is also one of the most effective measures to minimize the refusal risk.1. InstructionIn recent years, more and more oil platforms with six or eight legs have been adopted in Bohai Gulf, China. The leg piles with diameters of 2m or more have to be driven to about 100m below the sea bed. Such long piles have to be manufactured by segments before installation, because of transportation and hoisting difficulties. The segments of the pile will be assembled during installation, in which a successive segment will be attached to a formerly penetrated one by welding (Fig.1). The assembling work often takes one day or even a longer time."

Jan 1, 2014

By G. T. Hong

A numerical model for use in design is developed to predict the stresses and axial and bending displacements in a drilled pier in expansive soils. The prediction is based on the horizontal swelling pressures and uplift forces which act on the side of the drilled pier. The exponential suction envelope with the depth within the moisture active zone is estimated based upon the equilibrium suction, moisture diffusion coefficients obtained from laboratory tests, and minimum suction at the ground surface of the site based on field conditions. The volume change of soil is based on suction variations, soil properties, overburden pressures, crack influences, and the relationship between moisture contents and suctions. Considering the movement active and anchor zones on a soil-pile system in expansive soils, horizontal swelling pressures are formulated using the shear strength of an unsaturated soil and the Mohr?s circle and failure envelope. The movement active zone has two sub-zones in which horizontal swelling pressures are attributed to passive earth pressure failure and suction change in the upper and lower sub-zones, respectively. Horizontal swelling pressures which occur in the anchor zone are assumed to be in the at rest condition. The shear stress generated on the vertical surface of a drilled pier is supported by the nonlinear curves of load transfer versus relative displacement. The axial behavior and lateral bending of the pier in expansive soils are simulated using a beam column approach. The computed axial and bending displacements and stresses are used to provide structural design of the pier. Figures of computed results for typical cases are presented.

Jan 1, 2007