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By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

By Mazin Adnan

The 80m high dam at the Peribonka river in the Canadian province of Quebec was designed for the generation of 385 MW of hydro electrical power (Fig.1). The complex ground conditions required the employment of a variety of geotechnical construction methods stretched to limits never experienced before. Innovative grouting and trenching techniques were used for the construction of a plastic concrete cut-off wall down to a depth of about 116m, to cut hydraulic seepage through alluvial deposits forming the dam foundation. The bedrock where the cut-off wall is embedded forms a glacial gully with steeply sloped flanks, which created further challenging conditions. [ ]

Jan 1, 2008

By David L. Borusiewicz, M. Suri Surendra

"Abstract Helical piles have been used as anchors and for supporting lightly loaded structures as a method of underpinning, etc in the past. Recently, helical piles are being used to support new structures because of their simple installation process using relatively light and mobile equipment. This paper presents the results of evaluation and design performed for the temporary support of existing piers during a bridge rehabilitation project.INTRODUCTIONThe helical screw foundation was invented and patented by Alexander Mitchell in England in 1833. He installed screw piles to support lighthouses in the tidal basins of England. Many applications in the earlier years in the USA were in North Carolina and in Florida to support lighthouses (in coastal plain deposits). A lighthouse of similar foundation design is still in use at Key Biscayne, Florida.In the USA, the helical piles were reintroduced as foundation elements for electrical transmission towers. Helical piles were also used for anchoring guys of self supported towers and as tie-backs for excavation support systems. Typically, helical piles are being used for supporting lightly loaded buildings and for underpinning buildings undergoing distress as a means of remediation. The helical piles are not commonly used in the transportation industry.HELICAL PILESHelical pile is a segmented deep foundation system with helical bearing plates welded to a central steel shaft. Load is transferred from the shaft to the soil through these bearing plates. Central steel shafts are available in either a square shaft (Type SS) or a round shaft (Type RS). The Type SS series are available in 38 mm to 57 mm square sizes. The Type RS series are available in 73 mm to 114 mm diameter sizes. Type SS-RS combinations are also available for compression applications in soil conditions where dense/hard soils must be penetrated with softer/loose soils above the bearing strata.The leading segment consists of a shaft with one or more helical plates that are welded to the shaft. The plates vary in diameter from 203 mm to 355.5 mm and have a thickness of 9.5 mm or 13.7 mm. Typically the plate diameter increases from the bottom of the shaft upward. A helical bearing plate or helix is one pitch of a screw thread. All helices, regardless of their diameter, have a standard 76 mm pitch. Being a true helical shape, the helices do not auger into the soil but rather screw into it with minimal soil disturbance. Helical plates are generally spaced a distance of two to three times the diameter of the plate directly below in order for them to function independently as individual bearing elements. A typical detail of helical pile is shown on Figure 1."

Jan 1, 2014

By Harry G. Poulos

Ground movements can arise from a large number of sources and can have a significant effect on nearby piles and deep foundations. The loading of the piles by ground movements is a different mechanism to that arising from direct applied loading to the pile head, and consequently it is not generally possible to adequately analyze the effects of ground movements simply by applying some type of equivalent loading to the pile head. The main effects of ground movements are the development of additional movements, axial forces and bending moments in the piles, and thus the key design aspects are related to movements and to the structural integrity of the pile. However, the ultimate geotechnical load carrying capacity is generally not affected by the ground movements themselves. This paper will describe an approach to the analysis of ground movement effects on piles, considering axial and lateral movements separately. Some of the main features of pile response will be discussed for three specific problems involving ground movements: 1. Piles near and within embankments; 2. Piles near an excavation for a pile cap; 3. Piles subjected to seismic ground motions.

Jan 1, 2007

By C. M. Haberfield

"1 INTRODUCTION Around the world, there is a demand for larger structures, tall buildings and large bridges. While good footing design is important for all structures, it is even more important in the case of large structures. Recent experience with footing design for tall buildings (e.g. Burj Al Alam development and Nakheel Tower in Dubai, the Gate of Kuwait in Kuwait, the City Centre Project in Bahrain and Eureka Tower and Freshwater Place in Melbourne) has shown the benefits of investing in footing planning, design and construction (Haberfield, 2011, Poulos and Bunce, 2007). The footing systems for most of these projects include the use of deep bored piles or barrettes (piles of rectangular cross-section). Many use piled rafts where the piles, while acting to support the load, are primarily used to reduce settlements. A clear understanding of the factors controlling the behaviour of the footing system is needed to enable a good engineering design to be achieved. This starts with a sound understanding of the ground characteristics and individual pile performance, including adequate collection of data and testing. The best footing solution can then be found using recent improvements in data collection and analytical techniques, complex and highly capable computer-based models and the availability of high speed computers. This paper focuses on the axial performance of deep bored piles socketed into rock – both their individual performance and their performance as part of a larger footing system. Recent research and construction practice is discussed. In practically all cases, serviceability conditions control the behaviour of the footings. Methods of establishing the parameters for input into sophisticated computer programs are described. Application of the methods to case studies is included and it is shown that the behaviour of individual piles can be closely predicted. These developments lead to lower construction costs, better constructability and shortened construction time because of the better understanding of footing behaviour. 2 FACTORS AFFECTING PERFORMANCE OF FOOTINGS ON ROCK For a typical pile-supported footing, it is necessary to consider both individual pile, pile group and raft performance. These require consideration of the behaviour of the ground immediately beneath the surface raft or footing, along the pile shaft, and at and beneath the pile toe (Figure 1). Immediately beneath the surface raft or footing, the important factors are strength for bearing capacity and stiffness for settlement and interaction effects. Along the pile shaft, of most interest are strength for bearing, excavatability and stability; stiffness for settlement and interaction effects; geology and permeability for pile stability and, most importantly, pile shaft resistance. At the pile toe all the above factors for the pile shaft are present and in addition the pile end bearing is of interest. Below the toe, stiffness for pile settlement is important to at least a depth of twice the building width."

Jan 1, 1900

By Joseph T. Coe, Siavash Mahvelati, Alireza Kordjazi

This paper introduces recent advances in stress-wave NDT systems for use in assessments of in-service foundation integrity and drilled shaft construction. The primary results of the laboratory experiments are very promising, as the acquired image was capable of differentiating changes in pile cross section as low as 0.3 cm. The preliminary results with the same hardware components on a relatively large scale cemented sand model were also promising. A brief overview is provided of both systems including hardware, survey methods, and data processing techniques, followed by a discussion on application of the results to QA/QC of deep foundations. INTRODUCTION There are two main applications in which current QA/QC NDT technology fails to provide sufficient information regarding deep foundation conditions: (1) detection of flaws in outside cover concrete of drilled shafts and corrosion in steel piling; and (2) evaluation of anomalies beneath the bottom of drilled shaft excavations. Previous studies have demonstrated the capabilities of high frequency stress waves for geotechnical and foundation evaluation purposes (Lee and Santamarina 2005; Coe and Brandenberg 2010; Coe and Brandenberg 2012; Coe and Kermani 2016). Higher frequency waves can visualize smaller anomalous features at the expense of higher attenuation and smaller propagation distance. Therefore, the goal of this study was to advance the state of NDT practice by development of a prototype high resolution stress-wave imaging system as proof-of-concept. The equipment and hardware were modular, which allowed simultaneous development of two system configurations for application to in- service foundations as well as drilled shaft excavations during construction. Results are presented based on two large scale soil models. The first laboratory model simulated section loss in an in-service steel pipe pile and drilled shaft foundation (Fig. 1a). The second model simulated anomalous conditions beneath drilled shafts excavations as might be encountered in areas with significant karst (Fig. 1b). For both models, evaluation of foundation conditions relied on the propagation of small amplitude seismic stress waves using hardware similar to those described in Coe and Brandenberg (2010) and Coe and Brandenberg (2012).

Jan 1, 2018

By A. M. Hanna

This paper presents the experimental investigation on the ultimate skin friction of batter piles. The model piles were pushed in medium dense sand deposits at different inclinations up to 30 with respect to the vertical and tested under axial compression loads. The decrease in the total skin resistance with increasing pile inclination can be explained in terms of the reduction of the ave­rage mobilized angle of friction between the pile shaft and sand. The analysis, which takes into account asymmetrical earth pressure distributions around the pile shaft, showed good agreement with experimental results.

Jan 1, 2010

By Michael Quadagno

Hudson River Pier 86, home of the historic USS Intrepid Aircraft Carrier and the Intrepid Sea-Air-Space Museum, is currently undergoing a $30M reconstruction. This project involves the demolition of the old timber pile supported pier and construction of a new 150 ft wide by 782 ft long concrete pier, built over the footprint of the old piles. The new pier consists of steel pipe piles, precast concrete pile caps, and a composite deck, made up of precast, prestressed concrete planks and cast-in-place concrete topping. This paper focuses on both the structural design and construction of the new pier, with emphasis on the pile foundation. Pier 86 is unique in that it is required to resist the extremely high lateral loads imposed on it by the permanently moored 898 ft long aircraft carrier during severe storms. A total of 360 steel pipe piles support the new pier. These piles, which are 24 in. in diameter and range in length from 58 ft to 175 ft, were driven down to bedrock. The piles, each having 200 ton allowable capacities, work together to resist the significantly large lateral loads exerted on the pier by the ship. The installation of the piles was unique in that all the piles, including the ?super-longs?, were fabricated to-length offsite, delivered to the site via truck and barge, and installed in one piece, eliminating the need for field splicing. The Pier 86 reconstruction will be completed within an extremely aggressive 18 month schedule, from January 2007 through June 2008. The refurbished aircraft carrier Intrepid will return home in September 2008, and the grand re-opening of the pier will be on Veteran?s Day 2008. This paper provides a case history for owners, government agencies, engineers, and construction professionals that will be faced with the challenges of designing and building new piers.

Jan 1, 2008

By Ramdane Bahar

"Abstract The design foundations can be performed using Menard pressuremeter rules that require a limit pressure and a pressuremeter modulus. In recent years, another trend of interpretation of this test is appeared. It consists of identifying the rheological soil parameters using analytical or numerical methods and then used to evaluate the bearing capacity and settlement of soil foundations using numerical software. This paper deals with the bearing capacity and settlement predictions of bored piles using two approaches. The first one is the method called ""Pressident"" which is a numerical program developed to analyse pressuremeter tests taking into account the Duncan and Chang model. The second approach is the method developed by Bahar and Olivari based on the generalised elastoplastic Prager’s model with the Von Mises criterion which is suitable to describe the behaviour of saturated clays under undrained conditions. The pressuremeter data, collected on various research and consulting projects are used to explore the relationship between limit pressure and undrained shear strength obtained by the two methods. Numerical calculations, by FLAC2D software taking into account the rheological parameters derived from these two methods, are performed in order to predict the behaviour of a single bored pile subjected to an axial vertical load. The predictions are comparedto the measured data.IntroductionThe Menard Pressuremeter test has been used extensively to measure in situ soil properties and for the design deep foundations in Algeria. These tests are an useful and economical way for obtaining reliable in situ properties of soils and provide the measurement of in situ stress-strain response of soils. From this test, the design foundations can be performed using pressuremeter rules that require a limit pressure, pl, and a pressuremeter modulus, EM. These two parameters are derived from the pressuremeter curve or deduced from existing correlations with undrained cohesion and internal angle friction (Ménard, 1957; Amar and Jézéquel, 1972), and are used to evaluate the bearing capacity of soil foundations and the expected settlements. But, they can also help to identify usual soil parameters required by simple constitutive models for soils in numerical calculations."

Jan 1, 2014

By Mohammad Eslami

The Tabriz-Urmiyeh Highway shortens the distance of north-western cities of Iran by about 130 km, resulting in improved access and efficient transit between Iran and Europe through Turkey. The highway crosses the Urmiyeh Lake, an inland lake surrounded by mountains. Due to the circulation of salt-water in the lake and the necessity to continue shipping between adjacent ports, a waterway should be kept open. Consequently, a bridge was built to provide access of marine traffic. A causeway bridge had a length of 1,260 m, comprising of 19 spans. In construction of the bridge, more than 400 piles having a total length of 32 km have been driven. For design of piles different methods have been used such as static analysis, dynamic testing, and correlations to in situ tests, such as cone penetration test (CPT). This paper presents construction of bridge substructure, full-scale piling tests, and methods of analysis used in the evaluation of the deep foundation capacity. The presentation includes an assessment of four current direct CPT and one CPTu methods to calculate the bearing capacity of the piles. It was found that the CPTu and dynamic testing are two suitable tools for rapid and optimum pile design and verification.

Jan 1, 2010

By Ryan C. Linthicum

A system of steel sheeting and multiple levels of high capacity double corrosion protected soil anchors were used to restrain a major slope failure that occurred at the base of the Watchung Mountains mid-way through construction of a 650,000 SF retail center along Route 22 in Watchung, New Jersey. The implementation of a design-build earth retaining structure was necessary to stabilize and repair the disturbed mountainside in a timely fashion to permit completion of the retail center on a fast track schedule. The tied back steel sheetpile wall was approximately 2,000 feet long and varied in height from 12 to 25 feet. The hillside extended approximately 350 feet above and 600 feet beyond the wall with the main failure scarp extending 50 feet above and 90 feet beyond. The wall was constructed in a top-down manner and required the installation of 475 anchors to resist loads of up to 70 kips/ft produced by the creeping hillside and groundwater flows from both a series of springs and steady state seepage through an inclined zone of fine sand. Incorporation of a unique tie point connection eliminated the need for a waler, facilitating and simplifying modifications to anchor locations based on anchor load test results and conditions encountered during construction. Post grouting also proved to be an essential element in the successful construction. This paper presents the design and the construction methods used to restrain the significant earth lateral loads produced by a slope failure using steel sheeting tied back with high capacity soil anchors with anchor loads distributed to the sheeting through a unique tie point connection on a fast track schedule. Installation techniques, testing programs, and construction quality control are also discussed.

Jan 1, 2003

By Robert Jakiel

The following paper is being presented to provide an understanding of the Deep Soil-Cement Mixing (DMM) performed at Contract C09A7 at the Fort Point Channel Site (FPC), for the I-90/I-93 Interchange of the Central Artery/Tunnel Project (CA/T), Boston, MA. The paper is written as a summary of the DMM from the DMM Contractor's perspective. The summary provides technical information and practical observations that are currently considered to be state-of-the art knowledge within the soil mixing industry. The observations and information are being provided by Robert L. Jakiel, Chief Engineer of SMW Seiko, Inc., who was the DMM Project Manager and Project Engineer for the A7 Joint Venture at FPC. The DMM was started in April of 1996 and completed in December 1999. The various acronyms and terminology used to describe the soil mixing are found in a section at the end of the paper.

Jan 1, 2000

By Robert G. Lenz

Control of ground water for construction purposes is an everyday occurrence in the U.S. Thousands of pumps are in service at any given time. Most of these applications simply consist of pumping water out of an excavation, generally with the aid of sumps. Modern hydraulic and electric submersible pumps permit these procedures because of their ability to pump solids and take air without losing their prime. These procedures work fine up to a point and permit the contractor to control his ground water problems adequately and at minimal cost. When that point is exceeded, the ground water problems sometimes are compounded. Over-application of open pumping techniques can result in slope failures, cofferdam instability, bottom heaving, boils, loss of ground, damage to adjacent structures and utilities, and assorted other maladys which could and should be avoided. This paper will deal with the options involved in ground water control, a discussion of the unwanted side effects of dewatering, and examples of ground water control projects in various cities around the U.S.

Jan 1, 1988

By T. Jason Hardell

The Victory Bridge project was contracted by the New Jersey Department of Transportation. The project included the construction of two 4000-ft precast segmental concrete bridges to replace the existing Victory Bridge that was built in the 1920's. The existing bridge was a swing span bridge that was in desperate need of replacement. The project was considered high priority due to the large maintenance costs to keep the swing span operating over the busy navigational channel. In March of 2003 construction began on the first bridge and by April of 2005 all of the segments were set for the second bridge. On September 5 of 2005 the second bridge was open to traffic. The total cost of the project was $110-million. The two new bridges required the construction of 24-eight foot and 32-six foot diameter-drilled shafts with rock sockets. All of the shafts were constructed in the tidal Raritan River working from barges. What will follow is a description of the construction techniques that were used to build these drilled shafts, the anticipated and unanticipated challenges that were encountered during the project, and the lessons learned.

Jan 1, 2005

By Robert A. Field

Static-Load Piledriving systems utilize hydraulic push to advance piles into the ground. Dynamic systems (ie. hammers and vibratory equipment) utilize impact, or vibration, to advance the piles. Static-Load systems are most commonly utilized in situations where noise or vibration would adversely affect the people, structures or equipment located near the site. Static-Load technology is most advantageous in situations where vibration, noise or access constraints make it difficult, risky or disruptive to utilize conventional piledriving systems.

Jan 1, 1995

By Robert Thurner

The underground car park "Admonterhof in the historical centre of Graz is an example for the technical and economical success of a complicated structural design using a concept on the basis of the observational method. The intention to built a 20 m deep excavation beneath a protected monument was accompanied by some essential issues: the preservation of the existing state avoiding extensive displacements by means of a girder grid of reinforced concrete, its support on large bored piles and small steel-tube piles with possible active compensation of differential settlements, the excavation support in none built-up areas with secant bored piles, the underpinning of existing buildings with different structures by means of jet grouting. Furthermore the hydraulic gradient and the permeability of a rock formation in a part of the excavation had to be explored with the purpose to control the inflow of groundwater with a level difference of more than 10 m.

Jan 1, 2006

By Shawna Munn, Jakub Hudler

This paper outlines the use of tunneling headwall softeyes for transit construction projects in the Greater Toronto Area (GTA) over the past decade. Due to spatial constraints, tunnel boring machines were used to construct the underground tunnels requiring the design of launch and exit shafts with headwall softeyes to facilitate tunneling operations. Variable ground conditions and shaft geometries lead to the development of innovative headwall and tunnel softeye design applications using fiber reinforced polymer (FRP) elements (beams, reinforcing bars, and tiebacks). This paper outlines the challenges and benefits associated with designing and constructing shafts using various systems. Lessons learned throughout design and construction of more than 20 structures over the past 10 years are outlined. The constructability challenges with using FRP and design performance are also discussed. For over a decade, the City of Toronto has been expanding its metropolitan transit network with a variety of new transit construction projects. Two recent projects in the Greater Toronto Area (GTA) for underground infrastructure include the Toronto York Spadina Subway Extension and the Eglinton Crosstown Light Rail Transit project. These add a total of 31 new stations and 18.6 km (11.5 miles) of underground transit (TTC 2017) (EllisDon 2016). Due to ground conditions and spatial constraints of existing surface infrastructure, these projects utilized tunnel boring machines (TBMs) to construct the underground tunnels requiring the design of various types of shafts and headwalls to facilitate underground tunneling operations. To allow for tunneling through the headwalls, these shafts were designed with “softeyes” - a section of the wall without metal reinforcement that allows the TBMs to tunnel through.

Jan 1, 2018

By Ali Ameli

Design loads are limited for piles relying upon toe stresses in rock due to uncertainty about the rock quality over the whole pile diameter because of rock mass properties or construction effects. The paper discusses the use of video images to evaluate rock quality at the bottom of piles socketed into graniodorite bedrock in a steel pipe pile project. Skillful interpretation was required to assess the 3D properties of the rock from video images. It is necessary to observe the rock mass characteristics near the project site for better perception of the rock features from the images. Video image interpretation skills were established by the evaluation of the cores drilled under the socket base and the results of pile loading tests. Correlations were found between rock appearance in the images and the rock socket drilling records. Rock socket acceptance criteria were developed through monitoring the drilling operations for the specific site procedures. Video images then served as one of the quality-assurance tools together with probing and pile loading test. Lessons and methods learned from video inspection in this project could be used to evaluate rock quality in similar cases.

Jan 1, 2006

By Timothy C. Siegel

This report presents the results of a synthesis on the design and analysis of ground improvement for liquefaction mitigation. The synthesis included an industry survey concerning the practice of ground improvement for liquefaction mitigation. Participation in the survey was solicited by advertisements in several trade magazines and by e-mail for the DFI membership. The survey participants numbered 150. Their professional roles include consulting engineers, specialty contractors, design engineers, government engineers, and academicians. They represent a variety of geographical areas including North/Central/South America, United Kingdom, Middle East, Caribbean, Hawaii, Japan, India, Egypt, France, Australia and New Zealand. Upon completion of the survey, several professionals in the field of liquefaction and ground improvement were interviewed for them to elaborate on the survey results. The interviews are included in the Appendix of this report. Financial support for the project was provided by DFI and Dan Brown and Associates PC. The concept of the liquefaction mitigation synthesis was developed by DFI?s Ground Improvement Committee in recognition that: (a) The results of recent research and post-earthquake reconnaissance have challenged previously longheld beliefs about liquefaction and associated mitigation techniques, and; (b) The DFI membership and the engineering/construction industry are interested to know if and how engineers and designers are subsequently adjusting their practice in consideration of recent research and post-earthquake reconnaissance. For more detailed information on recent research and post-earthquake reconnaissance, presentations are available from the State-of-the-Art Forum: Liquefaction Consequences and Mitigation that was held in St. Louis in 2012. A commentary of the state-of-practice in ground improvement for liquefaction mitigation (prepared by DFI?s Ground Improvement Committee) is included in this issue of the DFI Journal. The author would like to thank the participants of the survey and especially Mr. Mike Jeffries, Dr. Les Youd, and Dr. Ikuo Towhata for their willingness to share their expertise in interviews. The author also acknowledges Mary Ellen Bruce of DFI, Billy Camp of S&ME, Inc., and Marty Taube of DGI Menard (and Chair of DFI?s Ground Improvement Committee) for their signifi cant contributions.

Aug 1, 2013

By P. V. Chandramohan

"In ports, piled berths are designed and constructed for berthing of ships with a finite draught. Piles in a bridge foundation also have a large free stand above scoured level. The piles of these structures have to withstand large horizontal forces imparted by the impact of the approaching vessels or due to longitudinal and transverse action in a bridge. It is also imperative that these piles have to project out of the dredged / scoured bed. These piles are normally designed as slender compression members subjected to bending also. They are subjected to vertical load tests for assessing the soil resistance. Lateral load tests, as a rule, are also stipulated. IS and IRC codes stipulate a deflection criteria for lateral load test to arrive at the capacity. These tests are usually conducted on a working pile by jacking out two piles. At the time of the test, pile will be free headed. But in service, piles are fixed head. There is a large difference in deflections between a fixed head and a free headed pile. Besides, a free headed pile will be subjected to a much higher bending moment than the fixed head one. This will put the working test pile under risk of breaking during the test. The problem is analyzed with case studies. INTRODUCTION Vertical capacity of piles is assessed by static formulae. This formula is based on the soil properties obtained from random soil exploration and laboratory and in-situ testing. Since soil is not a homogeneous medium, properties can vary. The design parameters taken for computations may be different from the ones at the interface of the pile with the soil. The best way is to find out is by a load test. The code IRC:78-2014 has rightly stated that initial load test is part of the design process. This is true with the vertical load test. But there are certain problems with the purpose and inference of the lateral load test. In both the tests the criteria for acceptance is the quantum of movement of the point of application of the load. In the former, the movement is vertical and depends more on the compression of the soil than the compressive strain in concrete. But in the latter, this movement is partly on account of the flexural rigidity of the pile and partly due to the horizontal compressibility of the soil. The role of rigidity of the pile is more when compressibility of the soil is higher. Lateral load test is done by jacking one pile against another because it is difficult to get an independent horizontal reaction. Please see Fig.1 Photo."

Jan 1, 2015