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By Gregory J. Canivan

Three test pile programs were conducted in Charleston, South Carolina to evaluate differences in bearing resistance due to installation methods. The tested piles were installed with impact hammers and vibratory drivers through soft clays and/or loose sands into the Cooper Marl, a stiff calcareous marine clay or silt. Piles driven into the Cooper Marl experience significant capacity gain with time following initial installation due largely to pore pressure dissipation. Pile size and pile type were both known to affect pore pressure generation during installation and subsequently the capacity gain with time. The test programs were primarily conducted to optimize pile design values and construction methods with regard to trestle construction but the results also contribute to the understanding of driven pile behavior. High strain dynamic testing was performed on several open-end pipe and H-piles. The measured difference in long-term bearing capacity of the H-piles as a result of the two installation methods was negligible, while the short-term bearing capacity of the pipe pile was larger when the piles were installed using impact hammers. The lower short-term resistance in the vibratory driven piles is attributed to larger excess pore pressures generated during installation compared to those generated during impact driving.

Jan 1, 2002

By Robert B. Bittner

The Sutong Bridge across the lower Yangtze River in China will have, when completed, the longest span (1,088 m) and the highest towers (306 m) of any cable stayed span in the world. The foundations for this record setting span will also be record setting. They are located in water depths exceeding 30 m with maximum flows exceeding 3 m/sec. The soil at the site of the main pylons consists of layers of silty sands and silty clays extending to bed rock at 270 m below river elevation. This paper describes the innovative methods used by the team of foundation designers and constructors to support this record setting bridge at this very challenging site. This paper covers three specific topics related to the foundations of the Sutong Bridge: ? Design and construction of the 131 drilled shafts (2.8/2.5 m diameter and 114/117 m long) under each of the two main pylons, including the post-grouting of all drilled shaft tips. ? Design and construction of the scour protection for the two main pylons. ? Construction methods used to construct the waterline pile caps (113.8 m by 48.1 m by 13.3 m deep) under each pylon.

Jan 1, 2007

By P. M. Wiltcher

The construction of a deep structural slurry wall in a restricted city centre location is always a challenging prospect. However, when the city is London and the site is bounded on two sides by high level canals and a main traffic highway on the third, the challenges are greater than usual. The paper discusses the design considerations required by the principal contractor to accommodate a single high level lateral support, value-engineered, bottom-up construction technique and the impact this had on the design detailing and construction of the slurry wall panels. This paper discusses the logistical challenges successfully overcome during the construction of 65,000sq ft of 40inch thick, 80ft deep structural slurry wall in the City of London. The paper reviews the benefits gained from using the state-of-the-art hydraulic grab and rotator system. Technological advances in computer instrumentation and real time monitoring were utilised to assist the grab operators in consistently delivering deviational control during excavation better than 1:200. With working space always at a premium on construction sites, the need for high quality, pre-fabricated reinforcement cages has never been greater. This paper reviews the argument for off-site fabrication of reinforcement members.

Jan 1, 2006

The pile inspector is a critical element in the quality control process necessary for a successful pile installation project. This guide is intended to provide the inspector with a basic understanding of only one of the many components of this process - the pile driving hammer. Pile driving hammers are used to install both bearing piles for structure foundations and sheet piles (and soldier piles) as used in retaining structures. In a single document, this guide offers a general presentation of the operation of the more common types of hammers the inspector is likely to encounter. It should make the information in the contractor's hammer submittal for the project more understandable. It should also provide an appreciation for the importance of a properly operating pile hammer. Prior to the start of most pile driving operations, the contractor will normally furnish a submittal to the engineer giving the specific pile driving equipment that he intends to use on the job. This submittal should include the make, model, and type of the intended pile driving hammer or hammers and their operating characteristics such as ram weight, rated energy, operating speed, external power requirements and, other pertinent information. Frequently, the operating characteristics are provided in the form of the manufacturer's specification sheet. The engineer will review this information and when he is satisfied, approve it and pass it on to the inspector. The driving criteria will have been determined by the engineer or others (the geotechnical engineer, consulting engineer, contractor, etc.) from the results of static analysis (for minimum penetration), driving during a test pile installation, Wave Equation analysis, dynamic formula, pile instrumentation during driving, static load test, or a combination of these or other appropriate analyses. The driving criteria can be a minimum penetration of driven pile length (embedded length), or a minimum (or maximum) blow count per unit of penetration. The pile inspector should become familiar with this information prior to the start of the job and should understand or seek help to comprehend the terminology and intent of each specification.

Jan 1, 1995

By Dzianis Proshchanka, Yoshi Izumi, Koji Mitani, Ayuna Kitaura

"A new pile driving and drilling navigation system has been developed. It utilizes the commonly used surveying total station, combined with an innovative reticle. Conventional crosshairs have been replaced by a concentrically circular reticle called Baum. It allows for easily performed measurements of central axes of cylindrical objects such as piles, chimneys, electricity poles, etc. This provides several significant advantages compared to other existing systems. It is cost-effective as only one operator is required to control deviations in positioning and inclination. Furthermore, repetitive reinstallation of the instrument is not required for every pile driven or hole drilled. It is also a safer method, as workers have no need to be near a pile driver or drilling machine to perform the measurements. With Baum Station, necessary measurements can be performed away from the actual work area. Moreover, it is highly accurate with real-time solutions, as three-dimensional orientation information for the pile/drill is obtained simultaneously with the pile being driven or the hole being drilled. This allows for the highest levels of precision-control and correction to minimize eccentricity of the intended center positioning.INTRODUCTIONBackgroundIn foundation construction for structures, pile foundations are widely used for deep bearing strata. There are two patterns to driving piles: vertically or obliquely to the ground. The shapes of the piles are normally cylindrical. Vertical pile foundations are employed as the foundations of many structures due to their high workability. There is a problem however, which is that this method does not bear measurement data as construction accuracy is visually checked. On the other hand, tilted pile foundations are rarely employed because it is too difficult to ensure construction accuracy. In addition, commonly used percussion methods create noise and vibrations when the piles are hit, while there are advantages that thinner piles are available, ensuring earthquake-resistance, as tilted piles curb horizontal displacements of structures, which may be caused by earthquake ground motion. However, current requirements of cost reduction bring professional attention to tilted pile foundations, which can be driven reasonably and economically with much research of tilted piles having been carried out to improve their capacity. Also, a method of screwing piling has been developed, which produces small amounts of noise and vibrations. This method has solved tasks of workability and environmental burdens, and is becoming more and more common. However, there is a necessity to develop a method to accurately measure angles of piles’ axes in order to drive piles into the ground with appropriate angles. It is also expected to find out a way to control construction information, such as correction amount and driving record."

Jan 1, 2017

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

"1 INTRODUCTIONThe use of nondestructive testing (NDT) methods to evaluate the integrity of Augered Cast-in-Place (ACIP) and Drilled Displacement (DD) piles has been a subject of significant debate among engineers, contractors and NDT practitioners. This guideline document will illustrate the importance of reviewing all available information in conjunction with the NDT records. ACIP and DD piles have unique properties that must be considered when using a specific NDT method. Any evaluation of the integrity of an ACIP or DD pile must also include a thorough review of the detailed pile installation records and the site specific soil conditions. Long or theoretical descriptions of the methods have not been included in this publication. More detailed information about these NDT methods including their theoretical and historical backgrounds can be found in DFI’s Manual for Non Destructive Testing and Evaluation of Drilled Shafts (2004). Additional information can also be found in the more comprehensive textbook Nondestructive Testing of Deep Foundations by Hertlein and Davis (2006).1.1 PurposeThe intent of this guideline is to provide practical guidance for the proper interpretation of NDT results on ACIP and DD piles. Short descriptions of the main integrity methods available are provided along with several examples of how to use all of the information available to make sound engineering judgments about the results. This publication is a state-of-the-practice guideline to promote accurate engineering evaluations.For engineers inexperienced with NDT, these guidelines provide sufficient background information on NDT methods to help understand the limitations of the testing, assess the results presented to them, and formulate appropriate questions. This is particularly important for engineers charged with the responsibility to determine from those results what, if any, consequences there may be on the performance of the structure under construction."

Jan 1, 2016

By Bengt H. Fellenius

The design of pile foundations is much more commonly verified by means of a full-scale test, than is the design of other foundation units. The reason is not that our knowledge of pile behavior is more uncertain than our knowledge of other foundation types making the verification necessary, but more that the loads in a structure are more concentrated to single foundations in a structure founded on piles as opposed to structures on footings or mats. Therefore, should a pile cap fail or move, the adverse consequence of this is often drastic, as the piled structure has little freedom to transfer its need for support to other foundation units. Consequently, it becomes important to assure the design of piled foundations. In many, maybe in most instances, the static pile loading test is routine and geared toward determining an at least capacity, only. However, in these times there is an ever increasing liability of the professional, demands for increased economy of the foundation, and frequent lack of the involvement in the test of the experienced old-timer exercising good judgment. Furthermore, modern pile design is leaving the single, simple concept of capacity and requires more information from the test to assist in determining aspects of long-term behavior and settlement. Therefore, even the straight forward, routine static loading test requires improved planning, execution, and analysis.

Jan 1, 1990

By Han Jie

The results of full scale plate load tests on stone columns on soft clay in coastal areas are presented in this paper. Four load tests were made, two of which were performed on the ground treated with stone columns, one on an isolated stone column and the last one on the untreated ground. For a given stress range, the settlement of the rigid plate, the stress concentration factor, and the excess pore water pressure were measured. It is found that the distribution of vertical stress beneath the rigid plate supported by the composite ground of stone columns is very different in shape from the one by the untreated ground, that the stress concentration factor has a relation with the stress level and time, that the stone columns increase the bearing capacity up to by 2 times, and that the ground stabilized by stone columns is of great advantage to keep the foundation stable.

Jan 1, 1991

Jan 1, 1991

Jan 1, 1998

By W. G. K. Fleming

The general history of piling is traced up to the present time with regard to the evolution of methods and materials. The processes have been strongly influenced by developments in basic equipment and industrial change. It is noticeable that in the twentieth century more progress has taken place than in the many previous centuries. It has been strongly influenced by the general development of Soil Mechanics. Test loading is probably the most effective way to assess the success of designs and many empirical relationships have been challenged through it. As we approach a new century it appears that it will be an age of rapid equipment development, with much enhancement of understanding of what has been done. Processes of automatic construction and testing will becoming commonplace. These changes will narrow the limits of conventional scatter that have come to be accepted and to a large extent will be driven by political efforts to curtail energy consumption, to raise standards of quality and reliability, and to conserve the environment. 1. Ancient history. Piling is an ancient art. Its first mention in history is from Herodotus, the first person to commit an account of his times to the written word in the years 557 to 479 BC. He evidently had a strong interest in engineering matters because he wrote of building, brick making, reinforced brickwork, river training, canal building, bridge construction, tunnelling and its acoustic detection and piling. The piling reference comes from Book 5 at paragraph 16.

Jan 1, 1999

By Bengt H. Fellenius

.1.1 Prior to commencement of pile installation operation, submit to [Engineer] for [approval] [review], details of equipment for installation of piles. SPEC NOTE: The information requested in 3.1 .1.2 is necessary as input to a detailed wave equation analysis of the pile driving. .1.2 For impact hammers, give manufacturer's name, type, maximum rated energy and rated energy per blow at normal working rate during easy and at termination driving, mass of striking parts of hammer, mass of driving cap, and type and elastic properties of hammer cushion. .1.3 For non-impact methods of installation, such as drilling, jacking, jetting, use of vibratory hammers, or other means, give full details of characteristics necessary to evaluate performance. .2 Impact Hammer SPEC NOTE: Do not exclude a hammer type unless for very specific reason. .2.1 [Drop hammers will not be permitted.] [Diesel hammers will not be permitted.] For final driving of [TYPE] piles, provide a hammer capable of delivering to the pile a non-erratic impact stress not smaller than [VALUE] Pascal and transferring a non-erratic energy not smaller than [VALUE] Joules per blow to the pile head at normal working rate.

Jan 1, 1991

By A. Flora, E. Bilotta, F. Foria, V. Nappa

"All the typical applications of deep mixing rely on the good mechanical properties of the improved columns to strengthen or stiffen the ground for a number of geotechnical applications.This paper focuses on a completely different kind of deep mixing, carried out in order to obtain columns much softer than the surrounding soil. This kind of deep mixing, named Soft Deep Mixing (SDM), is introduced as an original means to tackle seismic risk, and can be convenient when the existing structure to be protected has a historic relevance that cannot be altered with structural modifications. The idea is that properly assembled layers made of partially overlapped SDM columns, with dynamic impedance much smaller than that of the surrounding soil, will filter and reflect most of the seismic energy.The paper presents the results of some 2D parametric numerical analyses aimed to investigate the seismic performance of this innovative approach. Simplified dynamic inputs (Ricker wavelets, having only one largely predominant frequency) were adopted to better understand the effect of signal frequency. The analyses show that the effectiveness of the soft grouted isolating barrier depends on soil and SDM geometrical, physical and mechanical properties, as well as on the frequency content of the seismic input.INTRODUCTIONPassive structural systems installed at the foundation level of existing buildings are a common solution to protect them against earthquakes. However, installation procedures are expensive and not always feasible, as for instance in the case of valuable buildings. As an alternative, ground improvement techniques can be used to modify ground properties, in order to mitigate the intensity of shaking at ground level. The propagation of shear waves in the ground can be modified by introducing a layer of artificially modified material, having a dynamic impedance (defined as n =p VS, where p is the material density and VS the velocity of shear waves) very different from that of the natural soil. Both very high or very low values of the dynamic impedance of the grouted soil (nt) can be effective in reducing the overall transmitted energy, with the difference that – for a given reduction of the transmitted energy - stiff grouted layers tend to filter the low frequency components of the amplitude spectrum without modifying in a significant way the high frequency components, while soft grouted layers have the opposite effect. Then, ideally the choice of the best grouting technique should be made considering the effects of the different frequency components on the building to be protected. These effects are detrimental for the structure when they are close to its natural frequency: high frequency components result into large structural loads on massive squat structures (high natural frequency), and low frequency components may be critical for tall and flexible structures (low natural frequency). Therefore, the typical procedure of stiffening the uppermost soil layers regardless of the kind of building to be protected is not necessarily beneficial, and for the case of squat structures soft grouting should be preferred. However, this procedure has not been taken into account yet in the engineering practice, and may pose static problems at ground level (i.e. excessive static settlements)."

Jan 1, 2015

By Melissa S. Beauregard, Randall A. Pietersen

This study focuses on quantifying the effects of water infiltration on a full-scale energy pile system’s ability to meet the thermal demand of an HVAC system. Theoretically, an energy pile system should increase its thermal capacity after a rain event due to increased moisture content creating an increase in thermal conductivity of the surrounding soil matrix. The United States Air Force Academy has an energy pile research site consisting of 8 full-scale energy piles located below a shower facility. The local colluvium surrounding the piles allows for relatively high water infiltration during rain events. This study uses an 11kW Precision Geothermal Geocube to apply a thermal load on two single-loop piles. A weather station located south of the structure records atmospheric conditions. Results indicate that moderate rain events can caused up to a 23% increase in the system’s thermal exchange capacity. This change is due to the increase in moisture content near the surface, which penetrates to deeper soil layers with time. The time required for moisture to penetrate to greater depths and then dissipate in the soil matrix, explains why increased system performance is seen for over a week following the passing of a singular rain event. 1 INTRODUCTION With a “future-forward” focus, there is an ever-pressing economic and environmental need to use sustainable sources to meet growing energy needs. HVAC is typically responsible for 34% of the overall energy required by commercial buildings and 48% of the energy required by residential buildings (USEIA, 2009; USEIA, 2012). Energy piles are a low cost, sustainable technology that have been used to offset this energy demand incurred by a building’s space heating and air conditioning requirements. An energy pile consists of heat exchanging elements in a closed loop system integrated into a building foundation and connected to a ground source heat pump (GSHP). It is most common for these heat- exchanging elements to be constructed within a drilled shaft foundation due to both construction practices and geometric considerations. This system operates based on the principle that at a certain depth below ground (typically 4 meters) subterranean temperature remains constant at a value equal to the mean annual air temperature at a given location (Kavanaugh et al., 1997). This allows the soil to function as a heat sink for cooling operations and a heat source for heating operations when exchanged within this zone of relatively constant temperature. For the past 25 years, the implementation of energy pile technology in public, residential, and even large-scale architectural complexes has slowly expanded which has created an increase in research into the topic as a result (Brandl, 2006; Hamada, 2007; Sekine et al., 2007; Gao, 2008; Bourne-Webb, 2009; Stewart and McCartney, 2013; Murphy et al., 2014). When pile construction takes place beneath the groundwater table, soil is under fully saturated conditions, maximizing thermal exchange for a GSHP system. Under unsaturated conditions, however, changing moisture contents change thermal conductivity values in a soil, which affect a GSHP system’s ability to meet a thermal demand. The observational data presented in this paper apply to GSHP systems in unsaturated soil conditions.

Jan 1, 2019

Jan 1, 2001

Jan 1, 1988

Jan 1, 1989

By Manasi Wijerathna, D. S. Liyanapathirana

"Deep cement mixing is a popular soft ground improving technology that improves the bearing capacity and settlement characteristics of natural soil. When Deep Cement Mixed (DCM) columns are installed attached to each other in a wall configuration, the walls are capable of resisting bending moments and shear forces in the direction transverse to the columns. Therefore, installing DCM walls beneath the embankment slope perpendicular to the alignment of the embankment is a proper solution to prevent excessive lateral deformations of the embankment. Previous research studies have shown that failure patterns of DCM column walls are different to failure patterns of individual DCM column rows, under lateral loads. This study investigates the failure patterns of embankments where DCM column walls are located beneath the slopes, with respect to DCM wall strength, DCM column wall width and the spacing between DCM walls. 2D and 3D numerical models developed using the ABAQUS/standard finite element programme, were used in this investigation. Results show that the DCM wall strength and width of the DCM wall have a significant influence on the failure mode and the critical failure surface of the embankment. 3D simulation results demonstrate that the failure due to soil extrusion between columns was less pronounced in embankments improved with DCM walls, due to the interaction between the DCM walls and the surrounding natural soil.INTRODUCTIONEmbankments constructed over soft ground are highly susceptible to global slope failure and excessive displacements due to combined effects of vertical and lateral loads beneath the embankment slope (Zheng et al., 2009, Han and Gabr, 2002). The overall stability of the embankment can be significantly improved by improving the soil beneath the slope of the embankment using Deep Cement Mixed (DCM) column rows or overlapped DCM column walls (Jamsawang et al., 2015, Larsson and Broms, 2000, Topolniki, 2004, Broms, 1999). According to the literature, the improved ground experience different failure modes other than shear failure, such as separation of columns, overturning, shear failure along the columns or dowel action (Broms, 1999). Some of the failure modes reported by Broms (1999) are shown in Fig. 1. The ultimate failure mode depends on the geometry and the strength of the improved ground (Jamsawang et al., 2015, Kitazume and Maruyama, 2006, Kitazume and Maruyama, 2007)."

Jan 1, 1900

Jan 1, 1994