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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 J. J. Beresford

The primary function of a support slurry is to provide stability during excavation. Today foundation structures can be designed around the additional friction afforded by the absence of the filter cake attributable to the use of polymeric fluids as support slurries. These fluids use pseudoplastic fluid viscosity to advantage over the fragile thixotropic gel structures of bentonite. Many of today's polymeric fluids are environmentally acceptable for disposal directly to municipal sewers.

Jan 1, 1989

By James J. Anderson

In this talk I will report on an effort to reassess the risk of pile driving to juvenile salmonids migrating through Puget Sound. The study was motivated by the concern of the construction industry that provisions restricting pile driving during the spring migration is resulting in an unbalanced burden to the industry. In simple terms the industry wants to know if some construction can be conducted in the spring without harming the juvenile fish. Fisheries agencies have agreed to reconsider their regulations in the context of additional studies. So, in this talk I will present some thoughts on risk assessment in general and the results of our study to assess the impact of pile driving on Snohomish River juvenile pink and chum salmon that migrate through the Navy Homeport construction site at Everett. The research, which is being carried out by the Fisheries Research Institute at the University of Washington, was planned and is supported in a joint effort including: the Washington Department Fisheries, National Marine Fisheries Services, U.S. Fish and Wildlife Service; General, Manson, and Hurlen construction companies, the Department of Transportation and a number of Puget Sound ports authorities. I will first briefly discuss the early life history of the juvenile salmon the regulations are designed to protect Second, I will outline the legal criteria required for risk regulation and some specific thoughts on how a reassessment of pile driving risk might be approached. With this basis I will report on our research and how it can be applied to a new risk assessment.

Jan 1, 1990

By Edwin W. Meyer

The augered cast-in-place piling technique was used to install deep foundations 20 feet into weathered sandstone. The project involved the upgrading of the Air Quality Control System (AQCS) for a 560 megawatt coal fired power plant located in Stillwater, Minnesota. The site subsurface consisted of 20 feet of overburden overlying weak sandstone. The overburden consisted of sands and gravels with cobbles and boulders, and variable thicknesses of peat. Ground-water at the site was approximately 8 feet deep. Two foot diameter piers were selected to facilitate installation through the cobbles and boulders in the over-burden and to penetrate the sandstone 22 feet. During installation of the first pier, the weak sandstone broke down to sand-sized material that could not be cleaned from the pier hole without the use of slurry to hold the material in suspension. However, the use of slurry would significantly impact both schedule and cost. Since the sandstone could be easily drilled with the pier equipment, it was believed that 2 foot diameter deep foundations could be installed as designed using augered cast-in-place piling techniques. A brief test drilling pro-gram was conducted to evaluate the viability of 2 foot diameter continuous flight augers penetrating 22 feet into the weak sandstone. The test drilling indicated that augered cast-in-place installation techniques should be successful. Following a short delay to mobilize the additional required equipment, construction commenced. Installation of the 2 foot diameter augered cast-in-place piling to a depth of 22 feet into the weak sandstone was successfully performed.

Jan 1, 2006

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 Scott A. Walker, Roberto A. Lopez, Lori A. Simpson, David A. Shook

500 Folsom Street is part of the new Transbay neighborhood in San Francisco, which is being redeveloped after the 1989 Loma Prieta Earthquake damaged a freeway viaduct; removal of the viaduct created parcels of land available for development. The development consists of a 42-story residential tower with a six-level basement. The slender, core-only structure was designed using performance-based seismic design. Subsurface conditions include undocumented fill, Dune sand, marsh deposits, sand, and clay, all overlying sloping bedrock of the Franciscan Formation. The building is supported on a 10-foot-thick mat foundation approximately 62 to 72 feet below street grades; clay, sand, and bedrock are all present at mat subgrade. Under a portion of the mat, sand susceptible to liquefaction was present. The variable subgrade conditions and potential for ground failure, along with the depth of mat subgrade below street grade, created a challenge for the design and construction team to solve. The ground below mat subgrade needed to be improved to mitigate the liquefaction potential and provide more uniform support. The areal extent and depth of ground improvement necessary to support the mat with an acceptable amount of deformation was determined. Settlement was analyzed and subgrade moduli were provided for design of the mat, with multiple iterations performed to converge between the geotechnical and structural models. Based on the project schedule and logistics, it was beneficial to work from street grade to improve the ground. In order to target the depths below the mat and minimize wasted effort and materials within the depth of excavation, grids of jet grouting were determined to be the most economical ground improvement method; however, it was challenging to install the columns from 65 feet above the top of the target zone. During installation, QA/QC was performed to check that the jet-grouted columns were installed to the design depth and diameter and developed the design strength.

Jan 1, 2018

By J. Stacho, Frankovská. J.

"Abstract The use of continuous flight auger (CFA) piles in Slovakia has increased significantly in recent decades. High-rise building of administrative centre Lakeside Park in Bratislava is based on piled-raft foundation. The technology of CFA has been used due to the advantages of this technology in comparison with driven and bored piles in local geotechnical conditions. Piles have been designed in accordance with Eurocode 7. Resistance of piles was calculated by using an analytical calculation model for bored piles according to Slovak technical standard and CFA technology has been taken into account by coefficient equal to 1.1. Settlement of piles was calculated by using a calculation model which is being used in Czech Republic and Slovakia. Two well instrumented static load tests were carried out to verify the pile design. The results of static load tests showed that the design was conservative. The paper presents analysis of numerical modelling of CFA pile and static load tests. Load-settlement curves and load distribution curves over pile shafts are compared. Software Plaxis 2011 has been used for numerical modelling. Hardening soil model allows considering over consolidation of Tertiary Silts and water pressure in deep sandy lenses. The article also presents the parametric study where the influences of pile-soil interface reduction factor, over consolidation ratio and material models of soils are analysed. The results of numerical modelling showed that the most appropriate results have been obtained when the interface reduction factor equal 0.9 and real behaviour of groundwater were considered. The conclusion of the paper confirms that mechanical behaviour of the ground can be better understood and determined by using FEM than analytical methods.1. IntroductionPiles are among the most frequently used elements of deep foundations. Piles transfer loads down to a suitable bearing stratum when the soil immediately below a construction is unsuitable. Piles are also used to reduce settlement of structure. At present, the requirements of limit settlement of structures are more stringent. Examples of these structures are commercial and administrative centres that form a complex of different tall buildings. High-rise buildings cause greater contact stresses than connected low-rise buildings. Pile foundations in such cases should be placed under the high-rise buildings to achieve an appropriate settlement.Resistance of piles can be determined from static load test results, in-situ tests and empirical experiences or calculations. Static load tests give the most reliable results, but these tests are also the most expensive. This is the reason for constant development of computational methods. Especially numerical methods give more accurate results by using more sophisticated material models e. g. hardening soil or hypoplastic model."

Jan 1, 2014

By Alexander Nikolic

The paper presents the foundation design and construction of a landmark urban redevelopment scheme in central London, UK. The scheme comprises the new Tottenham Court Road Underground station, Crossrail interchange box and associated over-site commercial development. The paper focuses on the design, procurement and construction of large diameter bored piles, up to 68m in depth, which form the foundation support system for the over-site commercial development at Denmark Place. The congestion below ground required an intricate foundation design solution which has been a catalyst for developing innovative load transfer arrangements and has resulted in the advancement of pile construction technology in the UK. The foundation system was also designed to cater for the construction of two significant elements of proposed below ground infrastructure. Selected large diameter piles have been constructed within 1.1m of live underground railway tunnels. An innovative D-shaped pile was constructed in a zone subject to particular spatial constraints. The proposed Crossrail tunnels will be bored within 1m of selected over-site development piles. In addition, a 30m deep excavation forming a new escalator box will be constructed in direct contact with the over-site development piles. The stakeholder engagement process is described together with the foundation design development and buildability assessment. The benefits from early collaboration between the designers and specialist contractors are highlighted. From an analytical design perspective, the entire foundation construction sequence was modelled in detail in order to assess the soil structure interaction and any potential adverse effects on existing elements of underground infrastructure. The results from the three dimensional numerical modelling simulation are compared with field monitoring data.

Jan 1, 2011

By Philip J. H. Ball

The new application and development of grout jacking processes has combined, over the last decade in particular, to provide a method by which the effects of new underground construction on superficial structures can be controlled to acceptable levels. This paper sets out the basic principles, processes and limitations of compensation grouting. It describes key elements of the philosophy and design and details the control systems required to perform satisfactorily. To illustrate the application, a case history is described for the construction of a shaft and tunnel within and beneath the prestigious structure of Harrods in London.

Jan 1, 2000

By David S. Yang

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

Jan 1, 2001

By K. Rainer Massarsch

In some parts of the world, vibrators are used extensively for different types of foundation engineering projects. If used correctly and in suitable soils then vibratory pile driving for example is very efficient. However, soil conditions and the installation procedure have great significance for the driving resistance and affect the bearing capacity of vibrated piles. Also the intensity of ground vibrations which are transmitted to the surrounding soil is affected by the vibration process. In spite of the increasing use of vibrators and the rapid development of vibrator technology, many aspects of pile-soil interaction are not yet understood. In order to asses the importance of factors, which govern pile installation (and extraction), it is necessary to consider the entire chain of vibration energy transmission from the vibration source to the pile, the interaction between the vibrating pile and the soil and the wave propagation in the subsoil, Fig. 1. [ ] Fig. 1. Transfer of vibration energy from the vibrator through the pile into the ground In the present paper, some important aspects of vibratory driving and their significance for pile installation and soil compaction will be discussed.

Jan 1, 1995

By Ali Porbaha

Rapid growth in the urban development requires continuous search for innovative technologies to construct complex infrastructure systems. Deep mixing is one promising construction technology that has a wide spectrum of applications for development and expansion of complex urban facilities. Large number of reported case history of the projects in Europe, Japan, and the US demonstrate the versatility of the technology compared to conventional methods of ground modification. A large number of factors influence the quality of the soil cement columns; some of these are rooted in the installation process and the effective use of machinery during construction. This paper attempts to present some issues related to installation of deep mixing that affect quality of the treated columns. Presented here are various installation patterns, installation machinery, installation sequence, effect of penetration/withdrawal injection methods, penetration/withdrawal speed, effect of number of shafts, rotation of the blade, shape and orientation of mixing tools, and rotational speed of the shaft on quality of the treated ground.

Jan 1, 2001

By Christian Divis

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Jan 1, 2002

By Garland E. Likins

High-strain dynamic testing of drilled shafts and cast-in-place piles has become routine procedure in many parts of the world today. Field testing is performed by measuring strain and acceleration records under impact of a falling mass. Wave equation analysis is utilized to design the weight, drop height and cushion of the hammer apparatus to assure a successful test. The Pile Driving Analyzer* (PDA) and CAPWAP* methods are used for data acquisition and analysis. Testing results yield information regarding pile static bearing capacity, structural integrity, and pile-soil load transfer and pile load-movement relationships. This paper discusses application of high-strain dynamic testing to cast-in-place shafts with emphasis on aspects unique to this type of pile. Suggestions regarding minimum requirements for good quality tests are offered. Five case histories reported in the literature are summarized and a sample specification is also included.

Jan 1, 1995

Jan 1, 1987

By Elizabeth M. Smith

The kcICON design-build project in Kansas City, Missouri includes widening the existing roadway, improving interchanges and grade separation bridges, and replacing the Missouri River Bridge. The Missouri Department of Transportation (MoDOT) typically utilizes steel H-piles and steel pipe piles as driven pile support for bridges. After bidding the kcICON project, the cost of steel rose significantly and the design-build contractor used an innovative approach to reduce foundation costs without significantly affecting the project schedule. The kcICON team conducted a value engineering evaluation of alternative foundation types for use at four grade separation structures. The result of the value engineering evaluation was selection of precast, pre-stressed concrete (PPC) piles as the preferred foundation alternative. Terracon developed a test program to evaluate the performance, capacity, and suitability of PPC piles at the site using a PDA and CAPWAP analyses. This paper presents the value engineering design, rationale for selection of PPC piles, results of the pile test program, and findings during production pile driving. The collaborative approach to the project by MoDOT and the kcICON team, combined with testing and a site-specific design approach, resulted in substantial savings for the design-build contractor.

Jan 1, 2009

By S. Bang

In recent years, suction piles and suction anchors have been used as underwater foundations for various offshore structures. They have been proven very versatile, effective, and environmentally friendly. This paper describes the load resisting mechanism, installation, and design of suction piles and suction anchors. Also included are brief descriptions of three offshore structures that have recently been constructed using suction piles and suction anchors. They include: a new breakwater system utilizing gravity-type concrete caisson superstructure on top of concrete suction piles; a floating breakwater system utilizing embedded suction anchors; and a foundation system utilizing suction piles for temporary mooring of underwater tunnel elements.

Jan 1, 2009

By Mario Mauro

The article illustrates the Hydromill technology, as applied in urban sites, and its advantages in terms of quality of the end product, mitigation of the construction impact, and optimization of the logistics at the site. Also highlighted are the main features of the excavation equipment and slurry treatment plant. Two recent urban applications of this technology in Europe are briefly described, together with the forthcoming application to the Central Artery/Tunnel Project in Boston. Introduction The Hydromill technology has been used extensively in Europe in the last decade for slurry wall construction in urban environments. In Italy, this technology has been applied by Ing. Giovanni Rodio & C., Impresa Costruzioni Speciali S.p.A. in two large projects. The first project is the construction of Stations Darsena and San Giorgio of the first metro line in Genova. The second project is the "Cut-and Cover" tunnel for the railway link in Torino. Hydromill technology will be used for the construction of the Soldier Pile Tremie Concrete walls of the Boston Central Artery Tunnel Project, contract C14C2, Utility Relocation at Fulton Street.

Jan 1, 1994

By John R. Wolosick

MACROPILES are defined as ultra-high-capacity micropiles, with working loads in excess of 250 tons. The piles are typically 9-5/8 to 24 inch (244 to 610 mm) outside diameter. They are drilled and grouted in place, with either large diameter steel bars and/or steel pipe reinforcement. The piles are typically tested to twice the working load. Piles with working capacities of up to 500 tons and tested to 1000 tons have been installed. The paper discusses MACROPILE design philosophy, construction techniques, and two case histories where this innovative foundation system has been installed. Macropiles are descended from micropile technology pioneered in the early 1950s by Fernando Lizzi of Italy.

Jan 1, 2006

By Mel Febesh

Working in New York City has become the graveyard of many Foundation Contractors. Varying subsurface conditions require Foundation Contractors to be aware of the conditions at each particular site and have the knowledge and equipment to successfully complete the project. Looking back, we can see that many of the methods and much of the equipment that were commonly used in the past have been replaced with newer methods and equipment, but sometimes the old methods prove to be the most reliable. This paper will describe examples of varying conditions and construction methods in sites that are close to each other. It will also show different construction problems that are encountered when working adjacent to existing subway structures, when excavating below the foundations of adjacent structures and when ground water is encountered.

Jan 1, 2000