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By Don C. Warrington

This paper is a survey of the various methods and research efforts by which the drivability of piles is determined. First, a brief outline of the basic theory and the important parameters for driving by vibration are presented. Then, a wide variety of methods by which the drivability of piles is determined are presented and discussed, with special emphasis on methods developed in the USSR. Each of these methods are examined as to how they take into account the various parameters of vibratory pile driving, such as eccentric moment, frequency, dynamic force, motor torque and power, vibrating and static weight, and other variables. Some relation of these methods of field data is presented as well.

Jan 1, 1989

By Jamey Rosen, Georgette Hlepas

"Bluestone Dam is a concrete gravity structure with an overall length of 2,060 feet and a maximum height of 165 feet above the streambed. Several major project modification designs have been implemented and additional modifications are currently in construction and design phases. Due to the various modifications since original construction was completed in 1948, detailed documentation with visualization of the project features is needed. A three-dimensional model of the internal and external features of Bluestone Dam was generated from LiDAR data, survey information, and other data sources. One of the key features of interest in this model is an accurate visualization of over 200 dam anchors based on downhole anchor surveys. The model is accessible in Microstation and Geographic Information Systems (GIS), allowing users to rotate the anchors in three dimensions; view them in the context of geology, internal dam structural features, historical construction records, site photographs, bathymetric data, and instrumentation data. Users can “click” on individual anchors to view associated construction details and open a comprehensive installation packages. The model will be used by the United States Army Corps of Engineers (USACE) as part of a larger Geospatial Data Management System as a historical accounting of the project construction data, and be a long-term living document for use by both design engineers and operations staff to assess dam safety risk and to design future project modifications.IntroductionDuring the life of any project, critical data concerning the construction and performance history are required to be collected and maintained. The data collected prior, during, and post-project construction help with the design process, ensure that the project is built to specifications and is performing as per design intent. During the Post-Implementation Evaluation (an evaluation performed after a major project modification), these data are used to visualize the repairs, verify the construction was performed per design intent, and document the history of the construction phases, associated test results, and overall effect on the project. The project described in this paper is the construction of a system of tools to effectively use these data.Data collected and maintained during the operations phase helps to ensure that the project is continuing to perform as per design and aids in advance warning of any potential failure or required maintenance. Dam Safety, Emergency Management (EM), and Operations and Maintenance personnel can use the system to verify the status of the project in preparation for a high flood event. For example, if there is repair work being performed on a critical feature of the project that would affect the operation of the dam structure during a flood event, Operations personnel would be responsible to update the status of the system such that Dam Safety and EM would be able to identify the feature that is out of service, its date of expected repair completion, and the implications during a flood. In addition, risk assessments typically require a full history of the project and its performance. Any concerns that arise concerning the safety or performance of a project will require a full documented history of the project and its components. Proper documentation and data management are key in this assessment process."

Jan 1, 2016

By Jianhua Wang, Jianming Yao, Zhen Meng, Jinjian Chen

"Drilled screw pile is a newly developed displacement pile foundation which has been applied in soft clay for many years. Compared with traditional circular displacement pile, It is characterized by high bearing capacity, small volume and small squeezing effects. For the purpose of investigating the squeezing effects of drilled screw pile, a full scale field monitoring test with two test piles was performed. Detailed soil horizontal displacement and pore pressure measurements were conducted in the vicinity of the two drilled screw piles during penetration and subsequent soil consolidation. It can be concluded that the horizontal displacement of the surrounding soil induced by the installation of a drilled screw pile is mainly in a circular region with a diameter of 3 m (r/D<6), and the compaction effect outside the area can be essentially negligible; The excess pore pressures measured at the same time increase with depth throughout the entire process of consolidation, and its dissipation shows an exponential decay as a function of time.INTRODUCTIONA knowledge of the displacement and stress changes induced in the soil surrounding a pile is very important for evaluating pile performance. Numerous field and laboratory research projects have examined loading conditions, total soil stresses, and excess pore pressures during and following pile installation (Pestana et al., 2002). A relatively comprehensive and detailed review of these experimental works from 1948 to 2002 was presented by Pestana et al. (2002). More recently, Xu et al. (2006) conducted a field experiment to study displacements and stresses in the vicinity of two pipe piles during their installation in a soft lightly overconsolidated clay and compared the field measurements with existing predictive methods. Abdrabbo and Gaaver (2011) collected field observation data from four different construction sites to study soil disturbance during construction of piles using continuous flight auger (CFA). They have found that the disturbed zone of soil by CFA has a conical shape and the excess pore pressure has no appreciable influence on the load capacity of the piles.Drilled screw pile (DS pile) is a kind of vibration-free, cast-in-place concrete pile. Because of the excellent bearing performance, low level of vibration pollution and negligible spoil, as well as its fast construction speed, DS pile has been widely accepted by many engineers around the world. As a new type of drilled displacement pile, the significant installation effects of DS pile on the adjacent soil have not been systematically and integrally investigated yet. Since a proper numerical simulation of the real installation process of DS pile is difficult to achieve, the investigation based on field measurements is necessary. This paper presents a field investigation of the installation effects of two DS piles on surrounding soils. Detailed horizontal soil displacement and pore pressure measurements during pile installation and subsequent soil consolidation have been conducted. Based on the monitoring data, variation of horizontal displacements and dissipation of excess pore pressures with depth and time have been analyzed. What's more, the construction machinery and technology used in DS pile installation are also simply introduced."

Jan 1, 2015

By Nabil F. Ismael, Khalid Farraj

"The axial load transfer along large diameter bored piles in very dense silty sand was examined by field tests. Two instrumented piles 1.2 m diameter and with embedded length of 18 m and 25 m were load tested in axial compression to failure in connection with the construction of a big tower building in Kuwait City, Kuwait. Instrumentation included vibrating wire strain gages at various levels, displacement transducers and extensometers. The purpose being to measure the axial load distribution, skin friction, and base resistance at various load levels. In addition the settlement of the piles and the elastic compression were monitored. The ultimate pile capacity, side friction, and base resistance were determined and correlated with the Standard Penetration Resistance values as determined from the boreholes. Most of the load was transferred as side friction and the pile settlements at the maximum loads ranged from 1.6% to 2.2% of the pile diameter.INTRODUCTIONLarge diameter bored piles are used with increasing frequency for heavy structures in Kuwait and the Gulf region in calcareous sand. The behavior of short piles ranging in depth from 8 m to 15 m was examined by field test (Ismael 2012). However, larger diameter and deeper piles are being used more frequently, including the project described in this paper which included piles with 1.2 m diameter and 18 m to 25 m depth. The design of these piles requires knowledge of the skin friction and point resistance in these soils. While field tests on driven piles are available (Ismael 1989, Ismael 1999), field test data on long large diameter piles installed through very dense sands or silty sands are very limited at present. The results of two load tests carried out recently on instrumented bored piles at one site in downtown Kuwait City have become available. In these tests the failure load was extrapolated from the test results. It is important to examine and analyze the test results for the benefit of the geotechnical research and design engineers."

Jan 1, 2017

By Babak Mamaqani, Pirooz Barar

Regional Connector Transit Corridor (RCC) is part of the Los Angeles metro expansion project under construction which adds three new stations into the system. PB&A was responsible for the design of the support of excavation (SOE) systems for two stations, 2nd/Broadway and 2nd/Hope, in RCC. In this paper, challenges and lesson learned from SOE design of 2nd/Broadway station with a main focus on underpinning design are discussed. 2nd/Broadway station required to cut and cover excavation of 500 ft long by almost 100 ft deep, underneath 2nd Street. SOE systems consisting of drilled soldier beams with tiebacks and/or struts. The main challenge in 2nd/Broadway station was to underpin the LA Times building which was partially protruded into the station. A chellenging underpinning system consisted of concrete panels and ground anchors was designed to support the building surcharge and prevent settlement. The underpinning system was designed based on METRO design criteria and the deflection was evaluated by Finite Element Analysis (FEA) program, PLAXIS 2D. A maximum deflection of 0.4 inches was calculated to occur at the top of the underpinning system. Data from settlement and tilt sensors showed minimal movements which aligned with PLAXIS outputs. PROJECT DESCRIPTION The Regional Connector Transit Corridor (RCC) is Los Angeles Metro’s ambitious Light Rail Project. It runs under the City’s main thoroughfares, Flower and 2nd Streets, and when complete will alleviate traffic and parking congestion in downtown Los Angeles. The Regional Connector will connect thousands of residents living in the bedroom communities of the Inland Empire and Long Beach to their jobs Downtown. The rail line will serve 1.9 miles, using the $1.756 Billion budget to construct the underground rail line, including 3 new stations, at 2nd & Hope Street, 2nd & Broadway, and 1st St. & Central Ave (Fig. 1).

Jan 1, 2019

By David White

"When finished (projected completion in 2016) the Hong Kong-Zhuhai-Macau Bridge Project will comprise three cable-stayed span bridges and a 4.15 mile immersed tube tunnel - linking Hong Kong to Macau and the mainland Chinese city of Zhuhai. The design included two artificial Islands to serve as the transition structures for the tunnel to bridges, entailing a massive seaborne land reclamation project, and the use of thousands of sheet piles, and man-hours. The challenges of driving individual steel sheet in 100’ of water are well known, let alone in the open waters of the South China Sea.In 2010 a joint effort between American Piledriving Equipment (APE) and Allnamics Pile Testing Experts convinced the Chinese contractor First Harbor Marine Group China that a massive multi-vibro hammer can be used to drive 130’ long, 72’ diameter steel pipe piles weighing 662 US tons each into the sea bed of the South China Sea for the Hong Kong - Zhuhai - Macau bridge artificial islands. Combining APE’s hammer design, production and operation know-how with the pile driving simulation and installation know-how of Allnamics made it possible to show the feasibility of driving these gigantic piles into bottom of the sea to the required depth.INTRODUCTIONThe challenges of driving individual steel sheets in deep water are well known, let alone in the open waters of the South China Sea. Often the challenges of construction are overcome with engineering or equipment. The challenges of China’s Hong Kong-Zhuhai-Macau Bridge, on the drawing board since 1983, were to overcome both. The challenges of overcoming the skepticism of the Chinese Engineering community would be another story.The finished project will comprise three cablestayed span bridges and a 4.15 mile immersed tube tunnel linking Hong Kong on an eastern span to the China mainland cities of Zhuhai and Macau via two western spans."

Jan 1, 2017

By Sung-Ryul Kim, Woong-Jong Park, Juhyung Lee, Si-Hoon Lee

"A bucket foundation has been considered to be a potential foundation technology for offshore wind turbines. In this study, a series of 1-g model tests were performed to analyze the accumulated rotation of suction bucket foundations under long-term cyclic horizontal loads. The model suction buckets were made to have the embedment ratios of 0.5 and 1. The dry model ground was prepared to have two different soil densities by air-pluviation method. A horizontal cyclic load over 104 cycles was applied varying the loading amplitude. Test results showed that the accumulated rotation of the bucket foundation increased with the increase in the number of cycles and load magnitudes. Based on the model test results, a new equation was proposed to evaluate the accumulated rotation of the bucket foundations in sandy ground under long-term cyclic horizontal loads.INTRODUCTIONRecently, a bucket foundation has been considered to be a potential foundation technology for offshore wind turbines. In terms of economy, a bucket foundation has been considered to be an economical foundation type at sea beds where ground condition is clay or medium dense sand.A bucket foundation resembling a bucket is a kind of suction-installed foundation units. It is a skirted steel foundation which is open at the lower end and closed at the upper end by a lid. The embedment depth ratio (L/D) of a bucket foundation is usually less than one. Figure 1 shows an example of a bucket foundation. Offshore wind turbines are subjected to long-term cyclic loading by wind or currents. A bucket foundation is installed in soil grounds, so the long-term cyclic loading may induce the accumulation of soil deformation.In this study, the accumulated rotations of the bucket foundations in sandy ground were investigated under long term cyclic horizontal load. The number of cycles up to 104 cycles was applied varying load magnitude. The accumulated rotations of the bucket foundations in sandy ground were analyzed based on the test results."

Jan 1, 2016

"Standing 92 stories high and just over 1,362 ft tall, Chicago’s Trump International Hotel and Tower is perfectly positioned at the center of one of the world’s most impressive skylines.The Tower serves as a link between its famous predecessors, Willis Tower (formerly, the Sears Tower) to the south and the John Hancock Building to the north. Originally planned to be the world’s tallest building, the project was scaled back when the developers started questioning the need for super-tall buildings after the September 11, 2001 terrorist attacks. In its River North neighborhood, Trump Tower dominates the skyline as a symbol of Chicago’s last great building boom, standing triumphantly over other high-profile projects that have been postponed due to current economic realities.It is often said that the three most important factors in real estate are location, location and location. This maxim was not forgotten by The Trump Organization when the site was selected for the International Hotel and Tower. Located two blocks west of Michigan Avenue and Chicago’s famed Magnificent Mile, the site is bound by the historic Wrigley Building to the east, Wabash Avenue to the north and west, and the Chicago River to the south. The building’s position along a bend in the Chicago River allows visitors and residents unobstructed views to the mouth of the Chicago River and Lake Michigan. Site ChallengesUnderneath the site there are approximately 10 to 20 ft of sand and urban fill underlain by soft Chicago blue clay. At 75 ft in depth, the soft clay transitions into Chicago hardpan, a very hard till that was consolidated by the glaciers over 10,000 years ago. Below the hardpan, the till turns granular with cobbles, boulders and water under pressure. Bedrock is about 100 ft below existing grade and has a weathered surface with fractures and clay seams. Unweathered limestone bedrock is sound and hard with unconfined compressive strengths of 10,000 to 20,000 psi."

Jan 1, 2009

By Maurizio Siepi, Fabio Santillan, Lyndon Bedford, Carlo Crippa

"Abstract: Wolf Creek dam, on the Cumberland River in Kentucky, US, operated and maintained by the Nashville District of the USACE, is the Corps' largest reservoir east of the Mississippi river. The 1748 m (5,736 ft) long Wolf Creek dam combines earthfill and concrete gravity sections. Construction began in 1941 and was completed in 1950. The dam showed signs of instability in the 1960’s, and in the late 70’s an in-depth project of rehabilitation was undertaken, using both grouting and secant piles. The works saved the dam, but in the late 90’s further signs of distress worried the Nashville district of USACE which, after a study conducted on the water seepage, concluded that construction of a new concrete barrier cut-off wall was needed. In 2009, the $341.4 USD million contract was awarded to TREVIICOS-SOLETANCHE JV.The new wall, located upstream of the concrete monoliths, has a minimum thickness of 60 cm (24 in.), and runs the length of the embankment, into the right abutment, for about 4,200 feet. The founding depth reaches 84 m (275 feet), well below the zone of solutioning. With a total surface approaching 92,903 sq.m (1,000,000 sq.ft), the Wolf Creek barrier wall is unlike any other project in the world.The construction of the cut-off wall followed a complicated but logical sequence of several operations, involving a variety of technologies: grouting, hydromill, directional drilling, and secant piles with reverse circulation. The intensive rock grouting program was aimed to minimize the risk of slurry loss and extend the positive cut-off further deep. Subsequently, an Encasement Concrete wall was installed with hydromill, toeing into the rock, to protect the embankment during the following phases. Smart holes were then drilled into the Encasement wall down to the final depth. Eventually, the holes were used to install the secant piles by employing the reverse circulation piling method.An extensive verification campaign has confirmed the superior quality of the cutoff wall consisting of 1200 secant piles, exceeding by far USACE’s requirements. The main project was substantially completed in early 2013. A small portion of secant piles wall will be installed downstream of the dam, to close the switchyard, finishing the project in the early months of 2014.IntroductionWolf Creek Dam is located on the Cumberland River in south-central Kentucky. The Nashville District of USACE operates this multipurpose dam to provide hydropower, flood control, water supply, and water quality benefits for the Cumberland River system and surrounding region. Lake Cumberland, created by the dam, impounds 7,400 million cu.m (6 million acre foot) at its maximum pool elevation of 232 m (760 ft) above sea level. This lake is the largest reservoir east of the Mississippi and the ninth largest in the United States, and attracts 4.89 million visitors, more than Yellowstone National Park (2.87 million).This paper describes the recently completed works for the rehabilitation of the dam, accomplished by TreviICOS-Soletanche JV with the construction of a new Barrier Wall."

Jan 1, 2014

By Timothy C. Siegel

Accurate representation of the geotechnical resistance distribution is critical in evaluating the performance of piles and pile groups for design. A current practice is to infer the geotechnical resistance distribution based on measured changes in strain during conventional top load pile testing. Especially for drilled and bored piles, the residual load is typically assumed to be negligible both during testing and after the application of the structure load. A practical result is that the compressive structural load is anticipated to be opposed primarily by the shaft resistance with little or no mobilized toe resistance. The predicted top deflection is estimated as the combined elastic compression plus the movement necessary to mobilize shaft resistance. The development of residual load (and associated negative skin friction) results in a significantly different design condition. Negative skin friction tends to force the pile into the ground and develops residual load in the pile that contributes to the internal compressive load. Significant toe resistance can be mobilized in order to resist the combination of negative skin friction and the sustained compressive load. The pile movement becomes a function of the toe penetration required to mobilize sufficient resistance to reach a balance of forces. In an effort to study the development of residual load in augered cast-in place (ACIP) piles, the authors installed and monitored strain gages that were embedded in an 18-inch diameter ACIP pile at a site in southeast Georgia. The results of this study indicate that residual load develops over time and reaches a distribution that is consistent with the principles of the unified design of piles. It is concluded that residual load develops in ACIP piles (as well as all drilled and bored piles by the same mechanisms) and that the residual load should be considered in the interpretation of load tests and in the pile design, particularly in the estimation of the single pile and pile group settlement.

Jan 1, 2009

By James W. Weaver

The 2,120-foot long cable stayed Penobscot Narrows Bridge that carries US Route 1 over the Penobscot River between Verona Island and Prospect, Maine is supported on four foundation units, one below each pylon and one at each abutment. Due to varying subsurface conditions along the bridge alignment, the structure was designed to be supported on foundations consisting of high-capacity steel H-section piles (Verona Pylon), a mat bearing on a prepared bedrock surface (Prospect Pylon) and spread footings bearing on compacted rockfill (abutments). The 70-foot by 80-foot (plan area) Verona Pylon foundation was designed to be supported by 288, 430-kip design capacity steel H-section piles (HP14x117, 50 ksi steel) driven through up to 100 feet of dense glacial till deposits containing cobbles and boulders up to 3 feet in diameter. The piles were installed using a single-acting diesel hammer (Delmag D62-22) with a maximum rated energy of 165 kip-ft. Thirteen representative piles were selected for dynamic testing (ASTM D-4945) to verify pile capacity, hammer efficiency and pile stresses. Dynamic testing determined that four different pile driving criteria were needed across the site due to variation in the bedrock and soil resistance below the footing plan area. Approximately 4 percent of the production piles were damaged/rejected due to misalignment and/or damage as a result of encountering the cobbles and boulders embedded in the glacial till. The rejected piles were located randomly throughout the plan limits of the foundation mat. Subsequent structural analyses indicated that the foundation was capable of safely supporting the design loads without the need for installing replacement piles. Evaluation of dynamic testing results with signal matching and pile driving records provided valuable information on pile side and tip resistance. Evaluations were made regarding predicted versus actual pile lengths, pile bearing material, distribution of skin friction and end bearing capacities.

Jan 1, 2011

By M. England

Test equipment has been developed to record automatically both the displacement of the pile head and the load applied during a conventional maintained load pile test. Some systems also have, in addition, been fitted with the facility for maintaining the applied load, as set by the operator, at very constant levels. The advantages are both commercial and technical, but a well trained operator has to be in attendance to control the test. Since typical test specifications in the UK require more than 19 hours to complete, it became inevitable that at least one equipment operator remained on site to expedite the test for its duration. Although electronic measurement and data logging of load tests may be more safe than previous direct observation of dial gauges. A single person remaining on a construction site alone is not to be recommended, even if they are just supervising the test. Further development of the testing system produced equipment which will perform the entire test specification as required without operator intervention. To achieve this, full automation is employed. The patented method particularly addresses the safety requirements and by using additional sensors, detects any uncharacteristic behaviour of the pile under test or of the reaction system and the equipment takes appropriate action in a controlled and safe manner. The quality of test data returned from these automated systems is a key element when analysing pile behaviour with models such as CEMSOLVE? and TIMESETTM. These analysis methods often indicate ground disturbance resulting from installation technique and have allowed pile design to be optimised using actual field data rather than theoretical considerations alone. An additional feature is remote access, this allows the data recorded to be transferred and the progress of the test to be viewed from practically any location. This permits experts to view the data &apos;live&apos; and allows rapid diagnosis of any problems with the expected pile behaviour.

Jan 1, 2002

By Alan J. Lutenegger

Some years ago, a method was developed to incorporate a grout column around square-shaft helical screw-piles and anchors to increase shaft buckling resistance under compression loading. An additional benefit of this grouted shaft is to increase the load capacity in both compression and tension, depending on the geometry of the lead helical section and the soil conditions. Because of the unique construction procedure, the contribution of the shaft to the total capacity has largely been unknown. The behavior of grouted shaft helical anchors in clay was investigated by performing full-scale axial uplift (tension) load tests on a series of anchors installed at the University of Massachusetts Geotechnical Test Site. In order to isolate the contribution of the grouted shaft to the total load capacity, anchors were installed with a wooden dowel connection between the lead helical section and extension sections on three of the four anchors so that only the shaft resistance would be measured during the load tests. The grouted shafts ranged in length from 10 to 30 ft (3 to 9 m). Initial tests were performed approximately 5½ months after installation. Nearly four years after the initial tests were performed, the tests were repeated to evaluate any significant change in capacity with time and/or repeat testing (preshearing). The soil conditions at the site are presented along with the load-displacement curves for both the initial and repeat teats and a discussion of the analysis of the results. Repeat load tests showed an increase in capacity from the initial testing, however the percent increase was not the same for all depths. The results demonstrate that considerable shaft resistance can be developed in clays from the grouted shafts as might be expected. Depending on the L/D ratio of the shaft and the contribution of the lead helical section, at working loads the shaft capacity can dominate the behavior.

Jan 1, 2011

By Fathi Abdrabbo

Open caissons are used for many geotechnical engineering applications. Open caissons may be used as deep foundation elements bypassing weak soils to tip in firm deeper strata, and in rivers and maritime construction to reduce the risk of scour. Open caissons are also used for collecting sewage water through gravity sewer pipe networks or from sewer force mains. In such applications, the design and construction of open caissons require a detailed soil investigation program. In this way, the design and construction plan of an open caisson can be developed with full knowledge of the prevailing subsoil conditions. The engineering and construction techniques are key factors to achieve functional caissons. Based on close observations during construction stages, the current study presents some challenges that were encountered during the construction of two open caissons of internal diameters 20 m and 10 m (65.6 ft and 32.8 ft). This paper describes the procedure followed to alleviate the construction difficulties encountered. Site exploration program and control measures required to satisfy design and construction requirements are crucial aspects. Sinking of open caissons in dense or very dense sands is risky. Incorrect sinking of open caissons may cause extra cost, delay in construction, and harm to nearby structures. Air/water jetting near the cutting edge of an open caisson, outside slurry trench, and/or inside open trench may be used to drive an open caisson downward. Unsymmetrical work around an open caisson may lead to tilting of the caisson. If this occurs, the tilt should be immediately corrected before resuming the sinking process. Improper cleaning of fine materials on the caisson?s excavation bed, and/or inappropriate pouring of underwater concrete may result in a defective concrete seal. The paper contains a series of practical guidelines to assist those intending to use open caissons, and shares good caisson sinking practice with practitioners. Finally, the study aims to understand the difficulties encountered and to anticipate future problems.

Jan 1, 2012

By Jan A. Nilsen

This paper describes a key element in the construction of a major project undertaken by Harbourfront Corporation in its efforts to rejuvenate the central Toronto waterfront. The Spadina Pier forms one of the two major structures of the $10 million marina complex. Completed in early 1986, the 150 metre(490 ft.) long by 43 metre(140 ft.) wide pier structure will contain a 320 car parking garage as well as providing the foundation of a 17-story residential tower and a two-story retail/commercial complex. However, the pier structure posed a considerable challenge to its developers due to the the many restrictions imposed on the site by the environmental authorities which ruled out the construction of dykes or the placing of other fill materials on the highly contaminated bottom sediments. In addition, access at the site was restricted by its proximity to the main harbour navigation channel and a grain elevator berth. The original design called for a cofferdam to form an integral part of the finished structure. However, the contractor chose to regard the cofferdam as a temporary structure and proposed to construct the pier in the dry by enclosing the 10,000 square metre(107,600 sf) site with a 450 metre(1480 ft.) long single wall steel sheet pile cofferdom 7.5 metres(25 ft.) from the final pier structure. This paper will describes the design and construction of the cofferdam. Prior to finalizing the pier design, a geotechnical investigation of the shale bedrock was undertaken as well as a small sheet pile test cell program to evaluate the feasibility of driving a Canadian manufactured cold-rolled sheet pile into the bedrock. Relying on the design parameters for the shale bedrock, Foundation designed the cofferdam utilizing a post-tensioned bipod bracing system to resist a 7 metre(23 ft.) hydrostatic head as well as the maximum wind and wave forces expected at the site. The bipod bracing system consists of diagonal H-pile raker piles and verticle pipe piles anchored to bedrock with post-tensioned anchors grouted into bedrock.

Jan 1, 1987

By Javankhoshdel Yacoub

Piles are often used to reinforce slopes as they increase the available restoring force when calculating the factor of safety against sliding. In this paper, a 3D model of a slope containing multiple modes of failure is reinforced using pile elements. The results of the 3D Limit Equilibrium analysis containing piles are obtained using a newly introduced coupled approach which combines the results of finite element analysis (to obtain the displacement of soil along the pile) with the traditional limit equilibrium iterative formulation. The multiple modes of failure are obtained using the novel Multi-Modal Optimization (MMO) metaheuristic method which adapts the Particle Swarm Optimization (PSO) method to search for multiple local minima in a single slope model.

Oct 1, 2022

By Ameir Altaee

Unconventional means and methods were utilized to install over 650 contractor-designed micro-piles for the replacement of the Bronx approach to the Bronx-Whitestone Bridge in New York City. The method utilized reverse circulation (RC) drill rods and down-hole-hammers (DHH) along with grouting through the DHH bit. The overall construction sequence of drill-down, grout-up, place reinforcing is similar to auger-grout piling. The extremely tough drilling conditions required the use of a percussive DHH. The piling subcontractor refers to this pile as a hammer-grout pile. Project background, constraints and subsurface conditions are given. The proposed means and methods as well as the collaboration between stakeholders are detailed. Results of load testing and production installation are summarized.

Jan 1, 2010

By S. L. Karunakaran

There are cases where it is found that a raft foundation would have adequate factor of safety against ultimate bearing capacity failure but the settlements would be excessive. Piles may be introduced in order to limit settlements to an acceptable level. The actual number of piles required to reduce the settlements to an acceptable level may be very small compared to the number of piles required to transmit the whole structure load. The paper focuses on the difficulties encountered in evaluating the load sharing between raft and piles. An elaborate analysis taking into account the interaction between raft, piles and soil is very complex and time consuming. Few approximate methods for arriving at a satisfactory solution to piled raft system are discussed in the present paper.

Jan 1, 1996

By M. Y. Xia

In this paper, based on the Theological tests of the interface between clay and concrete, an interface Theological model is proposed and is used in the finite element analysis which takes soil as viscoelastic mass and Theological effect of the interface between diaphram wall and ground into consideration. Its results are compared with those without an interface element, without considering the relative creep displacement. Close attention is paid to the variation of wall with time under the condition of various interface shear stiffness and viscous sliding coefficient, and their effects on the wall bending moment are primarily verified in the paper. The change of wall bending moment with time, trench heave and wall displacement in different excavation depth, bracing position, parameters for soil are also studied.

Jan 1, 2010

By Ignatius P. O. Lam

This paper presents information on design analyses of large diameter piles using conventional p-y curves as recommended by the American Petroleum Institute (API RP2A, 1993). API RP2A adopted the soft clay criterion developed by Matlock (Matlock, 1970) based on 12.75-inch piles. API RP2A also adopted the API sand criteria originally introduced by Reese, Cox, and Koop (Reese et. al., 1974) based on 24-inch piles. Since Matlock and Reese published their original papers, there have been several publications recommending changes to their p-y criteria, especially regarding the need to adjust the Matlock p-y curves for pile diameter effects. The following sections attempt to clarify the issue of diameter effects on p-y curves.

Jan 1, 2013