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By Emad W. Shublaq

Contractual site plans are implemented for executing pile foundations (5 x 5) at segmental concrete bridge. Project schedule demands have forced the contractor to find out the most economical procedure in achieving the goal. This paper presents a site management technique which is applied by the Contractor. This was found to be fruitful and as much as 60% saving was gained.

Jan 1, 1992

By J. Nakayama

Down-the-hole hammer is commonly recognized as the most powerful drilling equipment for weathered to fresh rock formation including boulders. However, its drilling diameter is restricted by reasons of difficulty to actualize large diameter drillhead and to ensure discharging means of cuttings. Cuttings are usually removed by flushing i.e. uprising return air after compressed air actuates hammer, but in case of large diameter drilling, as the clearance between drill rod and surrounding wall of hole become fairly large, necessary up-hole air velocity to transport cuttings can not be maintained. In case of marine or underwater drilling or high groundwater table, orthodox down-the-hole hammer is obstructed its operation by water. This single head hammer drill combined large diameter drillhead with reverse circulation of drilling fluid enables large diameter drilling extending to 1.5 m, i.e. actualized large diameter mechanical drillhead incorporated with ensured cuttings removal means enabled this range of drilling. This paper introduces its features and actual applications to large diameter bored pile drilling for varied sorts of rocks in maritime construction projects.

Jan 1, 1996

By Gordon Demetrick

3900 Yonge St. was not a typical site on which to build a condominium apartment. A steep hill covered the majority of the site. In order to use as much of this site as possible, the rear of the building was to have nine stores cut into the face of the hill. A permanent shoring system was required as the building structure was not designed to provide sufficient stabilizing elements to support the total earth pressure. The total excavation depth required was 36 m (120'-0") with the upper 12 m (40'-0") to be backsloped. The vertical face of soil to be supported was 24 m (80'-0'). The shoring system originally designed by the Structural Engineer was to support this face by installing soldier piles and inclined earth anchors. During bid preparation it became evident to us that the system as designed would be difficult and expensive to install due to wet soil conditions. An innovative design was required to overcome these problems. Anchor Shoring hired John Stephenson Consultants Ltd. to aid them in accomplishing this goal. After extensive investigation together with The Trow Group, a unique design was proposed which provided a practical solution to the shoring problem.

Jan 1, 1987

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Jan 1, 1994

By Robert C. Rabeler

Soil and Materials Engineers, Inc. (SME) has utilized drilled cast-in-place (D-CIP) piles on a number of projects in the midwest. These foundation systems have typically consisted of drilling an 8 to 9-inch diameter borehole with a rotary type drill rig or driving a casing with a small hammer. A structural steel member is installed in the center of the excavated space, and the borehole or casing is grouted to complete the installation of the D-CIP pile. This type of piling system has also been called: mini-pile, micro-pile, or drilled-in pier. The capacity of these piles varies depending upon subsurface conditions, as well as the structural capacity of the pile. The structural capacity can be modified based on the size and yield strength of the structural steel member. SME has used the D-CIP piles for underpinning of lightly-loaded structures for a number of years. Steel brackets can be welded to the structural steel member in the center of these piles, and the bracket extended underneath existing foundations to provide proper foundation support. D-CIP piles have also been used for new construction where access was limited. Recently, SME had the opportunity of providing design as well as construction monitoring services for a unique project where these piles were used, but at much higher capacity. The project involved adding seven additional floors on top of a five-story building (total of 12 stories). New columns were extended through the existing building to support the new floors. Access to construct foundations was available to one level of underground parking beneath the structure, as well as to a basement area. Access required equipment to travel through a 3-foot wide hallway. A special duplex drilling machine was used to access the foundation locations and to install the piles in a limited headroom condition. Eight-inch diameter D-CIP piles were extended to a depth of approximately 40 to 50 feet below grade and socketed into a dense clay till or sandstone, and No. 18 or No. 20 threaded bars were installed in the center of these piles. The design pile capacity was as high as 190 kips and were verified by a compression load test. The load test was performed with limited access and headroom. These piles were installed by Spencer White and Prentis Foundation Corporation (SWP). For conditions where rock or hard soils are encountered at reasonable depths, D-CIP piles can provide working load capacities comparable to larger driven steel piles. The ability of the equipment to access very restricted areas, combined with the high capacities results in a very attractive solution to a number of difficult foundation problems.

Jan 1, 1999

This Workshop was held at the Doubletree Inn, Seattle, Washington from September 26 to 28, 1997. Run under the auspices of the Deep Foundations Institute (DFI), it was co-funded by the newly formed Japanese Association of Micropiles (JAMP), and the Federal Highway Administration (FHWA). The Workshop was jointly organized and facilitated by Fujita Research Corporation and ECO Geosystems, Inc., with close support by Donald B. Murphy Contractors, Inc. DFI kindly consented to publish these Proceedings. As is clear from the list of attendees, 42 specially invited engineers from all aspects of micropile technology were present, representing Japanese, European and American practice. This proved to be a most friendly and interactive group of people, who freely exchanged ideas, views and close comradeship, not only during the technical sessions, but (and especially!) during the numerous social events. Perhaps the best illustration of this came in Day 2 when the attendees were divided into five competing teams, each comprising representatives from the different geographic groupings. These teams had to quickly devise solutions to two technical problems (using standard data previously provided. A team of "referees" (who also acted as "coaches") later determined the most apposite response, based on constructability design concept, cost, schedule and so on. Not only were the winning team very liberal in distributing the prize (vintage California champagne) among themselves, but the whole Workshop soon benefited from their generous division of the spoils of victory.

Jan 1, 1997

By Dimitrios Polantzas P. E., Collin E. Sweeney E. I. T., Franklin M. Grynkiewicz P. E., Leili Javidanian P. E.

In the latest AASHTO design specifications, the Load and Resistance Factor Design (LRFD) method is prescribed for the design of retaining walls. However, inconsistencies arise when LRFD is used for retaining wall design versus the traditional Allowable Stress Design (ASD). Required toe embedment and wall loading demand vary greatly when the two design approaches are compared, all else being equal. This is due to application of linear load factors to properties that vary non-linearly in the design. These inherent inconsistencies are further intensified when introducing factors such as layered soil profiles, different wall types, groundwater elevation, and surcharge requirements. When applied correctly, these two design approaches, in theory, should lead the designer to the same result with little discrepancy, as they do with steel structure design. However, the use of the current AASHTO LRFD method for various geostructural retaining wall designs yields contradictory results that suggest existing retaining walls that have been successfully designed and constructed are unstable. Fundamentally, LRFD should be built on reliability-based calibrations; the successful past performance of existing retaining structures designed using ASD suggests that the LRFD approach requires considerable modification. The authors of this paper recommend that the current LRFD load factors be reviewed and revised based on more comprehensive wall performance data and wall type such that the difference between retaining structures designed using LRFD and those designed using ASD is eliminated.

Oct 1, 2022

By Brian P. Waagner

Construction law in general and the law of deep foundations in particular continues to develop rapidly, particularly in the areas of risk allocation. Public and private owners are increasingly using contractual disclaimers to shift the risk of differing site conditions to contractors, and courts are increasingly willing to enforce these contractual devices. Perhaps also in an effort to control costs, public and private owners are turning to design-build contracting techniques. While design-build offers many advantages over traditional project delivery systems, it does not answer all of the risk-allocation questions that frequently arise. Even in design-build, problems with unanticipated subsurface conditions and defective design are not easily addressed. Finally, developments in electronic commerce present the potential to transform the construction industry.

Jan 1, 2002

By Melvin I. Esrig

Lime Cement column stabilization of soft clay and sand in Salt Lake City, Utah and in San Francisco California is described and discussed. Stabilization permitted the construction, in a single stage, of a 14 m MSE wall on "medium" clay in Salt Lake City. It was used to mitigate the potential for liquefaction in San Francisco and to stabilize the Young Bay Mud beneath the BART extension to San Francisco Airport. These applications are described and the field measurements of performance are reported.

Jan 1, 2000

By James A. Schneider

Selection of resistance factors within Load and Resistance Factor Design (LRFD) requires accurate assessment of uncertainty and bias in load and resistance. To date, many studies have focused predominantly on the assessment of uncertainty, while the potential for bias appears to be the dominant factor in design for consistent levels of reliability under a variety of situations. Bias comes from factors which have been ignored in design method development but significantly influence resistance when extrapolating from conditions typical of databases to those at a given site. Uncertainty and bias can be quantified as the coefficient of variation and mean (or median) of a data set, respectively, for statistical assessment of load and resistance factors. This paper first presents an overview of statistical assessment of resistance factors, and then discusses factors that influence uncertainty and bias when extrapolating to situations outside of conventional databases of driven pile axial capacity.

Jan 1, 2009

By Franklin M. Grynkewicz

As part of the Boston Harbor clean up project, the new 1,000 mgd Deer Island Sewerage treatment plant includes ten 240 feet high egg-shaped "residuals" tanks. Contract documents called for these structures to be supported on 2,600 sixteen inch concrete filled pipe piles. The project site is underlain by highly variable glacial and marine deposits. Subsurface conditions vary from one extreme where firm glacial deposits exist at subgrade to the other extreme where 70 feet of medium stiff clays overlying weathered bedrock must be dealt with. The most common profile consisted of 15-20 feet of sands, 20-40 feet of marine clays, and 20-60 feet of stratified glacial deposits (commonly called tills) overlying Argillitic bedrock. Post bid redesign work, initiated as a cooperative effort between the owner and the general contractor, demonstrated that an $8 million savings could be realized if high capacity 48 inch diameter caissons replaced the specified pipe piles. A highly unusual arrangement of having the general contractor and specialty subcontractor providing input to the owner's engineering team allowed the redesign work to proceed on a "fast-track" schedule.

Jan 1, 1992

By M Muzammil, S. Mukerjee, S. Saran, M. Bharathi

"This paper presents the results of in-situ tests conducted on a set of under-reamed piles in a silty sand deposit. Three piles (i.e. vertical, vertical with one bulb and vertical with two bulbs) of diameter 0.2 m were cast upto a depth of 5 m. The pile cap had four foundation bolts cast into it so that a mechanical oscillatormotor assembly could be mounted centrally on it. The oscillator-motor assembly was used to generate purely sinusoidal dynamic forces, in either horizontal or vertical directions. For both horizontal and vertical vibration cases, it was observed that (i) the natural frequencies decreased with an increase in the excitation force level, (ii) for the same excitation level, the natural frequencies as well as the maximum amplitude of vibration are almost the same irrespective of the pile geometry i.e. number of bulbs in the pile, indicating that the full pile length is not being excited. For the vertical vibration case, the soil-pile stiffness at frequencies, before resonance, were observed to be higher than those at frequencies after resonance. In the horizontal vibration case, the stiffness of the soil-pile system was found to be decreasing with an increase in the excitation force level. The damping ratio was found to be increasing with an increase in the excitation force level.INTRODUCTIONUnder-reamed piles are piles, normally upto a depth of 6 m, with one or more bulbs along the pile stem. These have been used for structures like transmission towers, structures on expansive soils etc. for a very long time, however it is only in the last 30 years that dynamic response of a pile has been studied. Evaluation of dynamic soil-pile interaction is a very complex problem as the conditions and properties of soil are highly variable and unpredictable. Various models and approaches have been suggested by various investigators for evaluating the dynamic soil-pile interaction problem, but most of them are based on the assumptions that the behaviour of soil is linear and the soil surrounding the pile is strongly adhered to it. But in practice, it is not so. The soil surrounding the pile is always somewhat loosened and undergoes some deformation when a sinusoidal load is applied. This causes the soil-pile system to behave nonlinearly.In earlier studies by Novak, (1974), Novak and Aboul-Ella, (1978) etc. a linear elastic behaviour of soil was assumed. This approach was very useful in understanding the mechanism of soil-pile interaction to a large extent. Subsequently various models were suggested like the lumped mass models with nonlinear discrete springs, dashpots and friction elements Matlock et al. (1978), weak cylindrical zone around the pile model Novak and Sheta, (1980), ideal boundary zone model with non-reflective interface, Han and Sabin, (1995) etc. These approximate solutions give an idea about the mechanism of dynamic pile-soil interaction to a large extent. However, in reality both separation and slippage can occur due to the formation of a weak bond at the contact surface between the soil and the pile when a dynamic load is applied. In addition, the soil column adjacent to the pile experiences large deformations under dynamic loads and thus behaves nonlinearly.Some computer aided model studies on the dynamic response of under-reamed piles have been reported, however, very few insitu dynamic tests on under-reamed piles are reported. Dynamic tests on piles were carried out by Novak and Grigg (1976) on small scale single piles and pile groups in the field. Similar field tests on small scale piles were conducted to study the nonlinear behaviour of a single pile and a pile group under strong harmonic excitation by Han and Novak (1988), Han and Vaziri (1992), Burr et al. (1997), Manna and Baidya (2010) etc. The majority of these experimental studies were focussed on the response of the specific pile groups and compared with the results of a single pile. Hence there was a need to study the influence of pile g"

Jan 1, 2015

By George G. Goble

In the middle of the nineteenth century, the dynamic formula appeared as a description of pile penetration during impact driving. The simplicity of use of the formula combined with the power of the energy concepts behind the formula caused it to be quickly accepted and integrated into practice. Dynamic formula had been in use for 100 years when the Wave Equation computer programs first appeared. With that long experience it is not surprising that the formula continued to be used and were only slowly abandoned. The Wave Equation offers many advantages over the various formula but it does not offer a clear sense of physical understanding of pile driving that is available with the formula. Large amounts of numbers are generated but often it is difficult or impossible to gain a physical understanding of the results or a feeling for the importance of the various parameters. The question that the Wave Equation user has is, "What will happen if I use a larger drive cap (or change any other item of equipment)?" In this paper, I will attempt to explain pile driving using elementary wave propagation theory. However, the presentation will not depend on any higher mathematics. With the use of wave mechanics, it is possible to explain driving characteristics that cannot be handled with the energy formula.

Jan 1, 1995

By Robert L. Parsons

This paper describes the results of a detailed analysis of a loess deposit at the deep foundations test site established by the Kansas Department of Transportation. Multiple CPT, SPT, and pressuremeter tests were conducted as part of the investigation. This paper includes an evaluation of the effectiveness of common correlations used with the CPT, SPT when used for classification of loess and estimating its properties. Results show that common correlations must be used with caution as significant errors in estimation may result from using methods developed for other soil types. Laboratory testing included direct shear, triaxial, collapse, and consolidation testing, with many of the tests conducted on both vertically and horizontally oriented samples to evaluate anisotropic behavior. The results showed that strength properties could be considered to be isotropic.

Jan 1, 2009

By Douglas W. Christie

Deep foundations in Washington, DC have played a role in the city?s development since the 19th century. Designers of government and commercial buildings sought deep foundations initially to minimize settlement of structures. As the western portion of the National Mall was made by filling in portions of the Potomac River, numerous memorials and monuments on the Mall required deep foundations. In recent years deep foundations have been used to allow underground construction for various reasons. Commercial developers have sought to maximize the use of sites by developing below-grade space for parking to meet code requirements and offset the limits on building heights. Underground museum and gallery space has been constructed to expand public space while preserving open space above grade. Access and security concerns have prompted the design of underground visitor centers rather than above-grade structures.

Jan 1, 2006

By J. M. Mitchell

Kuala Lumpur, Malaysia is underlain by karstic limestone. Firm clays, mudstones and siltstoncs of the Kenny Hill Formation overlie the limestone for about two thirds of the city. The remaining third has deep deposits of very soft alluvium, or tin mining slimes, overlying the limestone. It is only recently that large buildings have been constructed in the area. Arup Jururunding have been concerned with several projects located on the limestone, although space here only permits the description of four sites in detail. The experience has allowed the development of a design approach for the foundations. The aim is to make the architectural scheme compatible with the geology. This is not always possible, and examples are given of both situations. The case histories give examples of compensated foundations, and piled foundations include steel H-piles, precast concrete piles, micropiles, bored piles with rock sockets, and barrettes up to 90m deep.

Jan 1, 2010

By Pete Howell, Patrick Granitzki, Alicia Plinio, Janitha Batagoda

The New York City Housing Authority (NYCHA) Red Hook Houses was subjected to damage during Superstorm Sandy. As a result, the NYCHA has an ongoing project known as Restoration Associated with Sandy Recovery Program to improve the resistance against future storms. The specific project included 28 residential buildings and several service buildings within the Red Hook Development. The subsurface conditions within the eastern portion of the site included existing fill material underlain by varying stratums of very loose, loose and medium dense silty sands followed by very soft to medium stiff clay or dense silty sands. The western portion of the site included existing fill material, very loose to medium dense silty sands and organic clayey silts underlain by very soft to medium stiff sandy silts. Based on the geotechnical report, a conventional driven steel pile system was specified containing two pile depths. As part of the project bidding, an alternative pile type was recommended and analyzed to provide quicker installation, reduce vibrations, reduce noise, and provide relatively large cost savings. Due to relatively high lateral loading, an innovative double steel casing drilled displacement piles was proposed as the alternative pile option. Field testing proved the piles capable of the required project capacities and the use of drilled displacement piles as the best alternative for the project and accepted by the NYCHA.

Oct 1, 2022

By S. T. Kok

This paper presents a case study in West Malaysia for passive piles failure in very soft marine clay in open excavation. In this particular case, the thickness of the very soft marine clay ranges from 5 m to 7 m (16 ft to 23 ft) from the ground surface. Preliminary site investigation reported SPT ?N? value of zero for the very soft marine clay. The design was based on a deep foundation utilizing driven piles to support the superstructure. During pile cap construction, the piles were subjected to uncontrolled open excavation, inducing bending moment in the piles, resulting in some cracked and broken piles. Analyses were carried out using an existing three-dimensional finite element code with a non-linear soil model to predict the response of these piles during excavation. Finally, the predictions of pile responses during excavation were compared satisfactorily with the observed results.

Jan 1, 2009

By Martin J. Kenwright

Within the famous Harrods department store, a new lift shaft has been constructed, servicing a depth of 22m below ground level as well as the existing 6 storeys of the store. The shaft will connect with a new goods tunnel which is to be excavated beneath the shop, as well as new floor space above ground level which has resulted from the infilling of a previously existing lightwell within the store. The construction of the deep shaft while maintaining uninterrupted use of the store by the Client led to a number of innovative solutions being undertaken. Empirical assessments were made of settlements anticipated from the construction process, which took place within a congested environment of existing foundations. Various elements were designed and installed to mitigate the effects of the inevitable ground movement on the surrounding overlying structure, which supported sensitive high quality finishes and mechanical and electrical installations The reinforced concrete lining of the shaft was contained within a cofferdam of minipiles. The minipile placement accuracy (1 in 150) was vital as it could not interfere with the subsequent tunnelling works. As the scheme progressed this became even more critical since the minipiles were needed as support for parts of the permanent works This paper describes:- the high quality placement and control of the minipiled cofferdam, the methods employed in assessing ground movements and the techniques used to mitigate against the effects of these movements.

Jan 1, 2000

By Kjell Karlsrud

"Abstract New semi-empirical design procedures for the determination of ultimate shaft friction and load-displacement response of axially loaded piles in clay are proposed. Hereunder also prediction of how the capacity will build up with time following the pile installation, primarily as result of reconsolidation. A main basis for developing the new procedures was detailed review and re-assessment of results from a series pile load test programs published over the past 30 years on piles well instrumented to monitor soil- and pore pressures as well as load distribution along the pile shafts. Two new alternative procedures are proposed for predicting the ultimate shaft friction; a-approach using the normalised undrained strength based on direct simple shear tests as a main correlation parameter, and ß-approach using the overconsolidation ratio, OCR. Both approaches include the effects of the plasticity index of the clay, Ip, which is shown to have an especially large impact on the correlations when Ip<25. It is recommended to use both methods in design practice, and select design values for the ultimate shaft friction that represents an average for the two methods. Pile diameter, length or stiffness, or whether the pile is open- or closed-ended seem to have little impact on the shaft friction. However, a moderate effect of pile length or flexibility on the total ultimate pile capacity comes out of the proposed t-z curves, which include some post-peak reduction. The proposed procedure for predicting the time for set-up is based on linear radial consolidation theory. The main input parameters are the insitu permeability and virgin modulus number (or virgin compression index) of the undisturbed clay. The same basic formula and correlations are applicable to both open and closed-ended or partially plugging piles.IntroductionThe design procedures presented herein are primarily based on observations and data collected in connection with “fully instrumented” pile testing programs that the author has been responsible for or has become involved with over the past 40 years, or that have been found in the literature.It was a pre-requisite for the test programs included that there were sufficient high quality soil data available to give a reliable determination of the true in-situ strength and compressibility characteristics of the clay deposits. The soil conditions range from soft NC clays with undrained shear strength down to about 15 kPa, to very stiff clays with undrained shear strength up to about 500 kPa and OCR up to 25. The plasticity index of the clays mostly lies in range 12 to 60 %."

Jan 1, 2014