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By Fabian Kirsch

Cyclic behaviour of axially loaded piles has been an issue since studies revealed that the capability to transfer skin friction into the ground is highly depending on the level and the number of load cycles the pile is subjected. It has been shown that degradation of skin friction due to axial cyclic loading leads to accumulating displacements and a severe reduction in pile capacity. In Germany the DIN 1054 as well as the Recommendations of the Working Group 2.1 ?Piles? of the German Geotechnical Society (EA-Pfähle) require the consideration of cyclic loading for the assessment of both the displacements and the capacity. Up to now no broadly accepted design method exists, which enables the engineer to give a reliable judgement on the pile capacity under axial cyclic loading and the displacements respectively. Instead numerous design charts make it possible to distinguish between stable and instable loading levels in order to ensure a design on the safe side. A newly developed design approach based on engineering models is presented which delivers a calculation algorithm for the remaining axial pile capacity after a defined number of load cycles to allow for the analysis of stability of the foundation. Furthermore the computation of accumulating displacements is made possible. The results are verified with pile load tests undertaken at Dunkirk, France and showed that the axial capacity after cyclic loading calculated with the newly developed design approach predicts actual capacity with an accuracy of ±20%.

Jan 1, 2011

By Robert Bittner

The following is a report on the development of two unique and separate cofferdam systems used in the construction of the marine foundations for the I-205 Columbia River Bridge at Portland, Oregon for the Oregon Department of Transportation. The first of these two systems utilized interlocking H-pile 100 ft long to form a cofferdam 145 ft by 58 ft in plan and 100 ft deep. The second system consisted of two immense bell shaped steel forms. The larger of the two forms was 83 ft by 66 ft in plan, 62 ft high and weighed 450 tons. This form was externally stiffened for a designed hydrostatic head of 54 ft. Both forms were designed, except for the top 14 ft, to be set and stripped in one solidly welded unit. The supporting geological formation for the bridge foundations is the Troutdale, a cemented sand and gravel. This formation is at the ground surface on the Washington Shore and slopes downward to a depth of 115 ft below normal high water at about mid-channel. In this area the Troutdale formation is covered with a layer of fine to medium sand 90 to 100 ft thick. It was the variable depth of the Troutdale which determined the two types of foundations and the corresponding to the two cofferdam systems.

Jan 1, 2013

By Giuliana A. Zelada-Tumialan

Reduced workability and flowability of the concrete through the tremie tubes and drilled shaft reinforcement have been identified as the main causes of tremie-concrete drilled shaft concrete defects. This paper discusses two recent case studies of defective tremie-concrete drilled shafts. The defects (soft inclusions, aggregate segregation, and low concrete strength) were primarily caused by the combined effects of the tremie placing sequence, rapid concrete slump loss, and poor passing and blocking characteristics of the approved concrete mix design. The level of detail contained in the drilled shaft specifications varied between projects. However, even when the specifications incorporated several of the more recent recommendations for tremie-concrete placement, the case studies showed that typical provisions for concrete mix proportioning and placement can be further improved to minimize construction defects such as those described in this paper. Based on the findings of the case studies presented, recommendations for the development of more effective specifications are provided. The recommendations include requirements for mock-up testing of proposed concrete mix designs and evaluation of the tremie-concrete placement sequence. Performance of such testing and evaluation would greatly reduce the potential for drilled shaft defects and consequent time and financial burdens associated with them.

Jan 1, 2009

By Dan Brown

A method is outlined for computing the contribution of a micropile group to global stability of a sliding mass. The forces in the micropile are computed in a way which accounts for the effect of soil mass movement on the mobilization of axial and shear forces and which maintains compatibility between shear and axial force as a function of displacement. The method provides a rigorous model to incorporate the pile forces into the stability calculations, including the effect of pile forces on the resultant shear and normal forces at the sliding surface. This paper demonstrates the proposed solution using a simple example slope.

Jan 1, 2007

By Giovanni A. Bonita

The United States Capitol Visitor Center (USCVC) is one of the largest underground structures ever constructed in the Washington, DC, metropolitan area. The 600,000 ft2 (55,750 m2) structure is entirely underground and immediately adjacent to the shallow foundations of the existing U.S. Capitol building. Interior building columns for the USCVC were supported on 186 drilled shafts that varied in diameter from 4 to 9 ft (1.2 to 2.9 m) and in length from 15 to 45 ft (4.6 to 13.7 m). The vast majority of the building utilities were located beneath the basement floor slab. It was decided at the onset of the project to proceed with construction prior to completion of the design drawings, and coordination between the underslab utilities and the drilled shafts had not yet been finalized at the onset of drilled shaft installation. Given depth and location restrictions of the outlets, relocation of the bulk of the utilities was not possible. Almost half of the drilled shafts were affected, leaving redesign as the most feasible remedial solution. The redesign involved adjustments to the shaft length, diameter, and bell. It took place on a case-by-case basis, sometimes only minutes before installation began. Coordination between the field and design team was excellent, and delay associated with the redesign efforts was minimal. In addition, the detailed, high-quality field records kept by both the contractor and field engineers allowed for accurate and fair estimations of the added drilled footage and concrete volumes placed. The additional service fee, which was minimal, was settled quick and fair.

Jan 1, 2006

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 Brian Langdon

The DRIVEN GROUT PILE was developed in 1989 by DeWitt Construction, Incorporated. This piling essentially consists of a cost-in-place concrete piling that reacts on a steel boot that is driven to bearing. This report will describe the driven grout pile, its background and its installation. The advantages and disadvantages of this system are also discussed. Finally, the results of actual field installations are presented and discussed. BACKGROUND The DRIVEN GROUT PILE was developed out of a need for a low-cost high capacity piling (100 ton) that could be installed with ordinary pile driving equipment. This search was motivated by attempting to incorporate the material economy of an auger-cast piling with the "empirical load test" of a driven pile. Typically, the least cost material for piling in the 100 ton range is concrete (grout). A grout shaft with minimal reinforcement can withstand a compressive load of 100 tons for a material cost in the range of $6.00 to $8.00 per lineal foot. A pipe piling with a capacity of 100 tons has a unit material cost ranging to $13.00 per lineal foot. The marriage of these two advantages resulted in the DRIVEN GROUT PILE. A pile that utilizes the economy of a reinforced grout shaft and has the loading confidence of a driven pile.

Jan 1, 1990

By David S. Yang

The construction of Oakland Airport Roadway Project for the airport expansion requires stabilization of subsurface soils for the construction of three grade separation structures at two roadway interchanges and the intersection of a roadway and taxiway serving the airport. Loose sandy fills and soft Bay Mud were improved by Cement Deep Soil Mixing (CDSM) for the construction of a soil-cement foundation under the MSE (Mechanically Stabilized Earth) walls of a roadway overcrossing and a soil-cement gravity retaining wall to maintain stability of a roadway undercrossing during and after a major earthquake. CDSM was also used to construct two cutoff walls for groundwater control. A test section was carried out prior to full production to verify that the CDSM equipment, installation procedures, and mix designs could produce the soil-cement with required strength, uniformity, and permeability to meet the design intent. Additional test sections were performed for the confirmation or modification of the mix design and installation procedure to cope with the complex subsurface conditions resulting from the historical development of the site. The test section revealed that the CDSM cutoff walls, retaining wall, and foundation improvements could be constructed to satisfy the design requirements and that the intermittent test sections alleviate the impact of the varying subsurface conditions. Based on the data obtained from the test sections, one CDSM cutoff wall was completed in July 2000. Full production of the CDSM retaining wall, cutoff wall, and foundation began in March 2001 and is expected to be complete in November 2001.

Jan 1, 2001

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 N. Shariatmadari

In recent years, determining bearing capacity of piles from in-situ testing data as a complement of static and dynamic analysis has been used by geotechnical engineers. In this paper, different approaches for estimating base bearing capacity of piles from SPT data has been compared and evaluated. A new method for pile base bearing capacity in sand is proposed using SPT records. Data averaging, failure zone extension, and plunging failure of piles have been addressed in the proposed approach. A data bank comprising 10 full scale static load tests on instrumented piles and 26 dynamic tests, analyzed with signal matching technique by CAPWAP software, was used for validation. The SPT data that was performed close to pile locations is also included in the data base. Comparison of current methods by error investigation with Log-Normal approach demonstrates that the proposed method predicts pile base capacity with more accuracy and less scatter in comparison to other methods.

Jan 1, 2006

By R. Heath Forbes

The route of a new, 4-mile long, electrical transmission line passed through residential neighborhoods and commercial areas of a small town in the South Carolina Coastal Plain. The new line consisted of 54 new poles and a one-mile underground section. Most of the new poles were constructed within 50 ft of existing structures, and in some cases, within 8 ft to 20 ft. A widely-space subsurface exploration consisting of 20 cone penetration test soundings indicated the subsurface conditions along the alignment generally consisted of saturated, loose to medium dense, fine slightly silty to silty sand. The pole foundations consisted of 20 to 30 ft long, prefabricated ?caissons? (essentially an open-end pipe pile with a prefabricated connection system at the top) with diameters of 28 to 56 inches. The steel caissons were installed with vibratory pile hammers. To help prevent damage and defend against possible allegations from nearby property owners, vibration and settlement monitoring was performed during all foundation installation activities. Limited structural condition assessments were also performed before and after foundation installation. For 53 of the 54 foundations, the ground vibrations recorded at distances coincident with the nearest structure locations ranged from 0.05 inches per second to 1.46 inches per second. With consideration of the dominant frequency, the majority of these values were below the commonly used USBM vibration limits. For a foundation installation that was only 8 ft from the nearest structure, a peak particle velocity of 3.06 inches per second was recorded, which exceeded the USBM limits. For all cases, the measured ground surface settlement was negligible (i.e., less than ¾ inch). Several spurious claims alleging vibration-induced damage were made, but the monitoring program provided an adequate defense. One claim involving artwork that fell to the floor during foundation installation at a distance of 8 ft from the house was deemed legitimate.

Jan 1, 2011

By Reda M. Bakeer

"Measurements obtained during load testing of two steel H-piles driven at a site in Northeastern Mississippi are discussed. The general site conditions, equipment used, testing procedures and results of the pile load tests are presented. Both piles were tested in compression and one of the piles was subsequently tested in tension. The piles were instrumented with strain gauges and extensometers to measure the mobilized soil resistance and pile movement. Three different “zero strain” conditions were used to determine the mobilized soil resistance and residual loads due to driving or a load cycle. It was concluded that the effect of residual loads on driven piles could be significant. Driving residual loads influenced the magnitude and distribution of the load transfer curves more than those due to a load cycle. Results of the tension test were impacted by the residual loads from the previous compression test performed on the same pile.INTRODUCTIONSeveral factors affect the performance of a deep foundation system including the subsoil conditions, loading settings, pile type and installation method. Residual stresses develop in piles particularly due to pile driving, but they are typically not accounted for in the analysis (Fellenius 2002). Siegel and McGillivray (2009) presented an assessment of residual loads measured during load testing of instrumented auger-cast-in-place (ACIP) piles. The magnitude and distribution of residual stresses along the pile shaft and toe depend on the pile installation method, previous load cycles and time effects. Poulos (1987) reported that residual load due to driving at the pile toe is independent of pile driving equipment and may significantly affect the results of a pile load test. Hunter and Davisson (1969) reported results of pile load tests performed in compression on fully instrumented piles driven in cohesionless soils along with a discussion of the effects of residual loads. Tension loads of about 445 kN (100 kips) were measured at the pile toe after driving. Unloading residual compression load at the toe was detected as “apparent” tension since the instrumentation was zeroed prior to the test. The researchers suggested a graphical approach to obtain the “corrected” load distribution curves considering that residual load will dissipate following the tension test. Holloway et al. (1975) conducted a study on the effect of residual stresses due to pile driving and developed a computer software that accounts for residual loads. Briaud and Tucker (1984) suggested a method to account for residual loads based on the results of 33 pile load tests performed in mostly cohesionless soils."

Jan 1, 2017

By A. R. Jambekar

City of Bombay has been developed out of former 7 islands. Landmass of 434 sq.km. of Bombay, started looking inadequate for further growth and expansion of Bombay City. In order to develope twin city of New Bombay, State Government formed fully owned Company "City and Industrial Development Corporation of Maharashtra Limited", (CIDCO) in 1971 and entrusted it with planning and development including social and physical infrastructure of New Bombay.Hence, Trans - Thane Creek area is being planned and developed, to serve as counter-magnet to Bombay. Area of 343 sq.km located on the main land, is fast developing into a satellite community, for India's overcrowded financial capital. Thane Creek, running in almost North-South direction, separates Bombay City from main land and posed a significant barrier, to further expansion of city's sprawling suburbs, until, it was bridged for the first time in 1972. On the basis of traffic study, CIDCO decided to construct an additional road link across Thane creek to cope up with future projected traffic. This bridge will connect Airoli in New Bombay and Eastern Express highway near Mulund. Bridging the vast, exposed tidal Thane Creek, have always posed challenging conditions, during constructions of these bridges. In this paper, case history of deep open foundations provided for Airoli Bridge is presented.

Jan 1, 1996

By Bengt H. Fellenius

Session 2, Deep Foundation without Soil Excavation, has attracted no fewer than 22 papers dealing with subjects from soil improvement by grouting, injection, and deep mixing techniques through vibroflotation and special piles, including aspects pertaining to conventional driven and bored piles. In the short time available, it is not possible to both do justice to the papers and provide a critical review of the state-of-the-art. Instead, to meet the objective of making the next half hour worthwhile to the audience, I have chosen to comment on a few special points brought forward in the papers and thereafter to discuss more in detail a couple of aspects I have deemed to be of general interest. Four papers deal with jet-grouting, injection, and deep mixing techniques: DOMSKI, J. J. Reinforcement of subsoil under the foundations of historical buildings in Cracow using deep injection technique. RESTELLI, A. B, BERTERO, M., and LODIGIANI, E. Deep mixing technology to improve the bearing capacity of a very soft clayey soil under an earth embankment.

Jan 1, 1994

By D. Arentsen

Changing environmental laws, new operating requirements and the increasing accuracy with which the bearing capacity of driven piles can be calculated have all led to the development of hydraulic piling hammers, some very primitive, others very advanced. Users find it difficult to decide which model is the most suitable, because the specifications are neither uniform nor unamiguous. There are no standard specifications and, moreover, the majority of hammers are suitable only for a limited range of applications. For the user, however, it is important to choose a hammer which will meet future as well as current requirements and will not quickly become obsolete or be unsuitable for a particular job.

Jan 1, 1987

By James Green

It has often been said that the best contracts written are by people who are suspicious of each other. The Spanish philosopher, Ortega y Gasset, said: "Every contract is an Act of Distrust." The arena for dispute settlement outside of the courts is increasing day by day - contracts, especially construction and civil engineering contracts, are written containing arbitration clauses for settling disputes - the very drafting of standard forms of contract, do in some instances by their very construction, create an ambiguity as to intent and provide a breeding ground for dispute. I come from a land far across the sea - the most southern land before the South Pole. Being a young country, 150 years old, we are still progressing - being far removed from the trouble free zones of the world and nuclear free we enjoy a lifestyle second to none.

Jan 1, 1987

By Stefan Aronsson, K. Rainer Massarsch

"ABSTRACT The geology of Sweden is characterized by the most recent glacial period with deposition of very soft clays and loose sand. Due to these difficult geotechnical conditions, new, innovative foundation and ground improvement methods were developed, which today are used in many other countries. Over centuries, Swedish scientists and engineers have made important contributions to the developments in foundation engineering. An important aspect of the success of Swedish foundation engineering in practice is the spirit of close cooperation between practitioners, engineers, and scientists. This has been achieved by the establishing of commissions, with the aim of finding solution of geotechnical problems. The paper focuses on developments in foundation engineering during the last century and does cover present activities in Sweden.IntroductionSoil mechanics and geotechnical engineering play an important role in Swedish society, as most construction activities require the consideration of foundation conditions. The objective of the paper is to summarize important developments in foundation engineering, primarily during the past century, which have influenced geotechnical engineering also in other countries. These achievements are the result of contributions by scientists, engineers and practitioners, only a few of which can be named. The paper does not claim to cover all aspects of geotechnical engineering, as emphasis is on the solution of foundation engineering problems from an international perspective. Thus, ongoing or recent research and development projects and activities within the geotechnical community are not included, as this would exceed the scope of the paper.Over the centuries, Swedish scientists and engineers contributed to the development of civil and foundation engineering. One important reason is the geology of Sweden, which is characterized by the most recent glacial period, resulting in the deposition of soft clays and loose sands in the coastal areas and dense glacial till in the interior of the country. Geotechnical engineering in Sweden has a long tradition and early contributions by several Swedish engineers and scientists have had a profound influence on the current foundation design in and beyond Sweden. A description of early Swedish geotechnical engineering has been presented in several publications by Flodin and Broms (1981), Broms and Flodin (1988), Massarsch and Fellenius (2012). The historic development of Swedish geotechnical and foundation engineering can be divided into four periods. During the “Early Era”, engineers were active in different sectors of military, civil, and mining engineering. Next, the “Industrial Era” comprised developments during the industrial revolution, when the transportation infrastructure of the country was modernized and extended. During the third period, possibly the “Golden era” of Swedish geotechnical engineering, which started at the end of the 19th century and lasted the following fifty years, geologists, engineers and scientists helped to establish modern geotechnical engineering. But also during the recent past, the “Modern Era”, several important contributions to geotechnical and foundation engineering which originated in Sweden, are used in many countries today."

Jan 1, 2014

By Charles Pol Vuillier

Piling work for modification to the Charles Grimes Bridge in Melbourne, Australia required piles to be installed through 15 to 20 m thickness of very soft to soft silty clay overlying 10 m of stiff clays and sands in turn overlying siltstone. The presence of an old sewer founded at depth in the soft clays demanded that vibrations be kept to a minimum. Two pile type were used by Vibro-pile (Australia) to provide the client with the most economical piling price. The two pile types were CFA piles of 750mm diameter founded in the weathered rock and a full displacement concrete injected screw pile developed by Vibro-pile called the "Z" pile, founded on the rock. The development and features of the "Z" pile are briefly discussed, including the perceived applications and advantages of the pile type. On board instrumentation comprising a computer was used to monitor all aspects of the construction. The rig instrumentation provided an important quality control measure that gave confidence in the pile installed. Pile performance was proved on the cast in situ piles by dynamic load testing methods. Initially tests performed with a 120 kN drop hammer, which was not capable of mobilising the required loads. The performance was then satisfactorily proved by using a drop hammer of 20 tonne mass delivering blows drop heights of 1.5m. Low strain integrity tests on a number of piles were also used to confirm the structural integrity of the piles.

Jan 1, 2000

By John F. MacDonald

From 19BS thru the present, Guy F. Atkinson Construction Company has been involved in several transportation construction projects in the Seattle area. Two of these contracts, the Mt. Baker Ridge Tunnel, and The Seattle Bus Tunnel, had unique foundation features. MT. BAKER RIDGE TUNNEL ACCESS PITS The Mt. Baker Ridge Tunnel is part of the general upgrading of the I-90 freeway between I-405 and I-5 (see Fig. 1). It is located on the western shore of Lake Washington and consists of a 1300 foot long large diameter tunnel thru Mt. Baker Ridge. The ridge consists of over consolidated silts and clays overlain by a loose to medium dense silty fine sand. The water table is perched in this upper layer of material. The clays of Seattle have a history of being very sensitive to excavation. The hills are marginally stable and numerous landslides have occurred recently in the area of the tunnel. [ ]

Jan 1, 1990

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