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By SungWon Park

The efficiency of the current design methods for computing pile resistances is evaluated using field load-settlement tests results. Twelve load-settlement test data for drilled shafts and bored piles were obtained from the literature. These load-test data were fitted using the ?t-z? method. Subsequently, the ultimate resistances were evaluated based upon the failure criteria from following methods: (1) the Davisson?s approach and (2) settlement corresponding to 5% or 10% shaft diameter approach. The ultimate resistances for these drilled shafts and bored piles were also predicted using methods based on the design code from North America (United States, Canada), Europe, and Asia (Japan). The pile resistances determined from field load-settlement tests were compared with those calculated using the design codes. The comparisons show that most design codes predict a conservative resistance for drilled shafts and bored piles. However, in the case of drilled shafts, we find that some of the design codes can over-predict the resistance and, therefore, should be applied cautiously. This research also shows that ?t-z? method can be successfully used to predict the ultimate resistance and the load transfer mechanism for a single pile.

Jan 1, 2009

By Stan Merjan

Composite piles with precast concrete tapered pile tips (TPT Composite Piles - U.S. and foreign patents) are a new and important addition to the piling types available to the construction industry. TPT Piles were invented by Stanley Merjan, Vice President of Underpinning & Foundation Constructors, Inc.. U. F. C. installs these piles in the Northeast United States and licenses piling contractors in other parts of the country. TPT Piles have been developed for use in sandy subsoils at depths to 70 feet or greater. The TPT system (see Figure 1) is simple. A pile stem of conventional material (shell, pipe, steel, wood, precast concrete) is connected to a socket formed in a precast concrete tapered pile tip (TPT). This composite assembly is then driven as a unit by ordinary pile driving methods until adequate driving resistance (established by formula or load tests) is met in a suitable soil strata. This driving resistance develops from the displacement and densification produced by the TPT. Many combinations of tip shapes and stems are available to suit particular job requirements with respect to subsoil conditions and pile capacities. TPT Piles should be considered for use on a wide variety of jobs. The advantages offered by a TPT installation include: ? High capacity piles in marginal soils ? Minimal lengths required to produce these capacities ? The use of conventional pile driving equipment and procedures ? Pile inspection techniques that are the same as for ordinary pile driving Furthermore, TPT piles are economical due to a combination of a low cost per ton of pile capacity and high productivity, both of which lead to significant savings in foundation costs and time required to complete foundation work.

Jan 1, 1987

By Richard A. Forth

During the construction of the Island Line (ISL) in Hong Kong between 1982 and 1986 piled foundations of a building were encountered in a tunnel drive. As the tunnel alignment could not be changed work was temporarily suspended whilst grouting took place beneath the pile cap. The tips of the piles were then cut off. The normal precast concrete lining segments were replaced by the "stiffer" spheroidal graphite iron segments and tunnelling resumed. Settlement of the building was found to be under 10 mm due to the tunnel drive and no damage was reported to the building.

Jan 1, 2002

By Gray Mullins

The construction of drilled shafts as well as other cast in place foundation alternatives relies heavily on good practices from the contractor, engineer, and inspector in order to produce a quality foundation element. As many of the installation methods involve blind concreting processes, it is difficult to be certain of an intact concrete mass of the intended dimensions. A new integrity test has been developed that provides additional insight into the integrity of drilled shaft concrete. By measuring the temperature throughout the shaft via standard access tubes, the measured temperature profile can be compared to the normal signature associated with a shaft of the specified size. This article provides an overview of the new method development, test procedure, analysis, and results.

Jan 1, 2010

By Antonio Marinucci, Robin Mao

The new Hangzhou West Railway Station, which is currently in the early stages of construction, will be located in the city of Hangzhou, China. To accomplish the ambitious goals of the project, the construction work and station building was divided into three project areas. The original design utilizes 1,580 drilled shafts with diameters of either 800 mm or 1000 mm (32 or 40 inch) to support the new Station and its various ancillary structures. The drilled shafts will be tipped into the moderately weathered argillaceous siltstone a distance between 5 and 15 m (16.5 and 49 ft), resulting in an effective pile length ranging from 35 to 43 m (115 to 141 ft), respectively. For the first phase, approximately 550 production drilled shafts will be installed. Eight (8) sacrificial drilled shafts each with a diameter of 1000 mm (40 inch) were installed to a depth ranging from 50 to 57 m (164 to 187 ft), and were tested to confirm the design parameters used for the first phase, to evaluate the contractor’s installation means-and-methods, and to provide guidance whether redesign is warranted for the subsequent two phases. Bi-directional static load testing was performed using a donut-shaped Super Cell to apply unidirectional axial loads up to 13,200 kN (2,970 kip). This paper will describe the bi-directional testing and select results obtained therefrom. The axial compressive and uplift resistances determined from the testing verified that the available axial resistance of a single drilled shaft exceeded the minimum design requirements.

By Richard Deakin

This case study describes aspects of the design of bridge foundations using 320mm diameter steel tube piles in the vicinity of Montréal, Canada. In this area, these piles are a very commonly used and cost effective solution for deep foundations. Typically they are driven through thick Champlain Sea Clay to bear onto stiff, strong rock. However, in some locations there is a layer of glacial till between the base of the clay and the rock which cannot always be fully penetrated by the piles. There is currently little published information, about the bearing capacity of these piles in the local till, and this paper presents and discusses some pile-test data from a recent project. The nature of the glacial deposits in the study area is presented using information gained from published geological data, the project ground investigations and site observations. The design approach and assumptions are discussed, together with the aims and outcomes of preliminary field driving trials and pile tests. The paper then discusses the results of dynamic tests undertaken on production piles. Bearing capacity factors are back analysed from the dynamic test results and compared against values assumed within the design. Observations are made that designers of future foundations in similar conditions may find informative.

Jan 1, 2011

By Frederick C. Rhyner

This paper describes the design and construction of two high-capacity rock anchors to restrain a supplementary backstay for the Bear Mountain Bridge, which is a suspension bridge spanning the Hudson River about 40 miles north of New York City. The supplementary backstay was installed to relieve a portion of the tension in the southern main cable, which had been creeping in recent years. The two new rock anchors were 1,200 kip capacity each, installed at a batter to depths of 59 feet. This paper describes the subsurface investigation, group capacity analysis, installation and load testing. The rock anchors included strain gages connected to the monitoring system for the bridge. The paper describes the long term strain gage data which shows no change in stress distribution in either anchor.

Jan 1, 2010

By Xiong Houjin

In the excavation works of some deep foundation pits within the boundaries of Guang­dong Province of China, though some measures, such as steel sheet piles, diaphragm walls, etc. were taken to protect the walls, the construction of the excavation works was often accompanied by damage of buildings and public facilities, surface settelment. sand boil and collapse of piles. When these happened, only chemical grouting could be used as the most efficient measure for rushing to deal with or rescue the emergencies. Besides, the application of chemical grouting protection wall technique also palys a very important role under the geologic conditions of the coastal areas of Guangdong Province, when applied in the mucky oystershell layer wealthy in water and the deep mud layer, it can not only achieve good results, but also reduce the cost significantly. In this paper, we discuss the water-tight and earth retaining functions of chemical grouting protection wall in weak formation, and introduce the applicable ranges of chemical grouting protection wall in the excavation of deep foundation pits. Some technological principles and design considerations of the construction of chemical grouting protection wall are presented. Different types of protection wall are also introduced.

Jan 1, 1991

By Gandhi

Piled raft foundation under uniformly distributed vertical loads has been analyzed using Finite Element Method. The soil is considered to be linear elastic, isotropic, homogeneous. The raft,pile and the soil have been idealized with eight noded brick elements. Parametric study have been carried out varying pile length, soil modulus, raft thickness, and pile spacing. Design charts have been produced to achieve 50% load sharing between pile and raft for optimum design. Data available in literature is compared with the design chart results and found satisfactory.

Jan 1, 1996

By Shuvranshu K. Rout, Anup K. Mandal, Biswajit Das, Manos De

"To adopt new technology advancement in Steel Plant, there is a requirement of shifting of operation process from Coke Wet Quenching (CWQ) to Coke Dry Quenching (CDQ). New CDQ chamber foundation with deep basement and underground conveyor tunnel are to be constructed in an operating plant where heavy foundations and structures are located in close proximity. Furthermore, the existing CWQ system will be in operation during new underground construction and erection. Challenges to deep excavation of tunnel and chamber foundation consist of non-uniform ground condition, prevent washing out of soil from bottom of existing foundations, stability of existing nearby structures, presence of large number of underground utilities, ensuring safe underground workplace to construction resources engaged in new construction work along with project schedule and budget constraints. A combination methods involving use of soil nailing, soil grouting, contiguous bored pile and micro pile had been adopted for protection of excavation sides as well as existing structures. Each side of excavation in different stretches were analysed during design as well as construction stages. The use of combination of all techniques in a single brown field project in context of the nature of site constraints and safety issues made this a unique project.INTRODUCTIONSteel Industry is one of the backbones of industrial growth of any developing country like India. Due to increasing land prices most of the steel plants in India are expanding within their existing plant facilities. In addition to that, there is demand of adoption of new technology for future expansion projects to set new benchmarks with global standards.The property owner had earlier installed a Coke Wet Quenching (CWQ) for their Coke Plant. Now, there is a requirement from process department to proceed with Coke Dry Quenching (CDQ). To facilitate the CDQ within the existing CWQ which will be in operation is the main challenge for the property owner. The second challenge is the limited space for underground construction and subsequent equipment erection within the stipulated time frame.From a geotechnical prospective, the project team had uncertainty and reservations in their mind about the construction methodology. Therefore, the role of three “C”: ‘Consultant’-‘Client’- ‘Contractor’ and their combining brainstorming is essential to freeze a working plan for achieving the goal. In this paper, only the excavation support systems for underground foundation structures have been highlighted in the context of solving geotechnical problems."

Jan 1, 2017

By François G. Bernardeau

Cement-bentonite (C-B) slurry walls have been used for ground water cutoff in deep excavations, contamination containment, and other applications. Hydraulic conductivity is of great concern for cement-bentonite slurry walls. The quality control program usually specifies permeability and strength tests to be performed in a laboratory on samples cast in the field and cured for a certain time. Currently there is no widely accepted in-situ test method for the performance of the constructed slurry wall. A recently constructed cement-bentonite slurry wall in South Carolina included a 200-foot-long test section done in advance of the production of an 8,300 foot-long wall. Intensive tests and investigation were conducted during and after the test section construction: Monitoring piezometers were installed using wet insertion method and packer tests were conducted in boreholes drilled in the post-28-day-cure slurry wall. The permeability measured from the packer tests was about two orders of magnitude higher than the design and the laboratory test values. Additional investigation was performed using a video camera to inspect the borehole walls especially the packer test sections. Test pits were excavated to observe both sides of the cement-bentonite slurry wall. A thorough inspection was conducted to evaluate the integrity of the wall. The lessons learned and issues regarding the disturbance effects of in-situ testing of cement bentonite slurry walls is presented and discussed.

Jan 1, 2008

By Shields H. Arup

The paper describes the innovative foundation reuse and strengthening works for two buildings in Central London. A 1950s building on piled foundations (65 Whitfield St) and a 1930s building (67-69 Whitfield St) on 3m deep pad foundations were both extended upwards by two new stories. The Client for the project is Derwent London, with Make as their architect, Main Contractor Multiplex and Engineer Arup. Little was known about the foundations of either building at the start of the scheme. Extensive investigations of the existing foundations and ground conditions were carried out in both buildings. At 65 Whitfield St, investigations identified piled foundations, but found that pile lengths were short and variable. As a result, strengthening works solutions were adopted whereby the increase in column load was shed into new mini piles constructed around the existing pile caps. At 67-69 Whitfield St, deep pits were used to investigate the foundations and reuse was justified based on understanding of the pad dimensions, concrete strength, and strength and stiffness of the underlying geology. For both buildings the residual risk was closed out through monitoring during construction. The combined reuse of the structural frame and foundations of both buildings facilitated a sustainable solution, breathing a new lease of life into outdated buildings.

May 1, 2022

1.1 The parties agree to submit all claims, disputes or controversies arising out of, or in relation to, the interpretation, application or enforcement of this agreement, including dispute resolution procedures, to sequential mandatory discussion, mediation and arbitration for resolution of all disputes before, and as a condition precedent, to self-help, arbitration, judicial action or other remedies. This mandatory procedure will resolve each dispute within one-hundred (100) calendar days. Any deadline falling on a federal holiday or weekend will be the next working day. Breach of this disputes process shall constitute a material breach of contract for which the aggrieved party may recover all costs, including attorneys fees, interest and other expenses necessary to resolve the dispute through litigation. The obligation to discuss and then mediate and arbitrate covers all disputes arising from every aspect of the Project to be built by the owner, including, but not limited to, design, engineering, bonding, indemnification, labor, material and services, and the acts or omissions of any related party for whom a party to this agreement may stand responsible.

Jan 1, 1994

By Emad Farouz

The resistance of very dense glacial outwash formations consisting of sand, gravel and cobble formations can be quite high, and techniques for measuring the strength and deformation properties often cause engineers to underestimate the strength of these layers in drilled shaft design. More realistic measurements of this dense formation can be achieved with slotted steel casing pressuremeter tests. To minimize disturbance and achieve accurate measurements, drilling a pilot hole prior to probe insertion is necessary. Characterizing geologic formations that contain significant amounts of gravel and cobbles is challenging because of scale factor. Inserting a standard pressuremeter probe into this formation without damaging the membrane is difficult. This paper presents a case study for the IR-75 project in Dayton, Ohio, USA, where these dense materials were characterized using a slotted casing pressuremeter, optimizing design by providing more realistic properties of these materials.

Jan 1, 2006

By J. -M. Rescoussier

Due to Important settlements inducing major structural damages, the western part of the Grand Littoral shopping centre has been closed in 1997. The present paper describes the project of underpinning including not only micropiles under the structure of the building but also a reinforcement of the soil located between the shopping centre and the edge of the embankment surrounding the western part of the shopping centre. The aim of this reinforcement is to reduce existing horizontal movements to allowable values.

Jan 1, 2002

By Helen S. W. Chow

The use of piled raft foundations for tall buildings has been increasing in this decade as it is an economical alternative to conventional piled foundations. Piled rafts are composite structures comprised of the piles, raft and soil and so soil-structure interaction is important in computing the behaviour of the foundation. In this paper, the behaviour of piled rafts subjected to non-uniform loadings will be examined where the raft is supported by piles of different lengths. Finite layer techniques are used for the analysis of the horizontally layered soils and finite element techniques are used for the analysis of the raft and piles. This method accounts for the soil-structure interaction and the lateral resistance of the soil on the piles and raft. Results provided from the present method are compared with the results of a full 3D finite element analysis.

Jan 1, 2006

By Timothy L. Roberts

For many years practicing geotechnical and structural engineers in Texas and Louisiana were reluctant to include augered cast-in-place (ACIP) piles as a viable deep foundation alternate. Three primary concerns were the lack of a final driving resistance to confirm adequate capacity, the inability to inspect ACIP piles prior to installation, and the fact that pile integrity is highly dependent on the skill of the ACIP pile contractor's field personnel. The Deep Foundations Institute (DFI) Committee on Augered Cast-In-Place Piles has responded to these quality control concerns by establishing standards of practice for ACIP pile installation and ACIP pile inspection. Regional areas of the country have different subsurface soil and rock conditions and many times this will influence local installation and inspection requirements. The best way structural and geotechnical engineers can address quality control concerns is to be familiar with the DFI standards of practice, to know the special requirements for a particular project site, and to incorporate them into a well-written ACIP pile specification. The purposes of this paper are to: 1) review the main fundamentals of a successful quality control program, 2) describe how these fundamentals can be applied to the installation of ACIP piles, and 3) add personal experiences from ACIP pile projects in Texas and Louisiana. Nondestructive test methods are frequently used as a quality control tool to evaluate questionable piles. An additional brief discussion of two nondestructive test methods is presented to complete the paper.

Jan 1, 1998

By Mark DeSalvatore

Currently, at Caltrans, the Office of Structure Design is carrying out an extensive seismic retrofit program involving transportation structures throughout California. The goal of the retrofit program has been to upgrade existing transportation structures to meet the present seismic codes and anticipated loads that are generated during a seismic event Part of the retrofit program involves retrofitting existing structure foundations when required. To determine if the foundations of a specific structure need to be retrofitted, an engineering analysis of the existing foundations has to be done. If the engineering analysis of the structure foundations determines that the foundations will not meet the load carrying demands required by the structural engineer, the existing foundations are then retrofitted. The retrofit projects that require foundation modifications can be separated into two general cases. The first case comprises structures where the original designs will not meet the demands of the present seismic design code. In this case, the existing foundations are not capable of providing the load capacities the current seismic code requires. The second case consists of structures where the retrofitting of the superstructure will increase the required load carrying capacity of the existing foundations during a seismic event In this case, the anticipated load demands on the existing foundations are greater than the foundations are capable of providing. For either of the cases listed above, the present strategy for increasing the capacity of the existing structure foundation consists of installing tiedown anchors or large capacity piles to provide the required resistance to seisraically induced loads.

Jan 1, 1993

By George K. Burke

Single axis soil mixing is a mechanical method of blending soil in situ with a reagent binder to achieve improved character. Generally this achieves a design compressive strength or shear strength and/or permeability, but can be used to immobilize and/or fixate contaminants as well as a treatment system for chemical reduction to a more "friendly" substrate. The reagent binder can be a variety of materials, including cement, fly ash, slag, lime, and an assortment of additives. Usually this reagent is delivered in a slurry form (combined with water), but the Dry Mix Method uses pneumatic conveyance.

Jan 1, 2001

By Michael D. Justason

...a global perspective... In March of 2000, the Japanese Geotechnical Society added "Rapid Load Testing" to their national standard for pile testing. In the year 2000. it is estimated that there will be more than 500 "Rapid Load Tests" on foundations around the world. ...so what is a "Rapid Load Test", and why is it gaining acceptance and popularity?

Jan 1, 2001