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By Yin Zongze

The pile foundation of Sutong bridge pylons is an extra large pile foundation. The length of piles is 115m, and the diameter of the piles is 2.5-2.8m. Since the traditional design method may not determine the settlement and capacity reasonably for such a large pile foundation, the finite element method is used to study stress and deformation of the foundation. The interface element is set to simulate the possible slide between piles and soil layers. The hyperbolic model is taken for soils. Parameters are determined from triaxial test first, and then modified by back analysis on basis of in-situ loading test. The computation results show that the axial force of piles changes with the location of the pile. Outer piles support greater axial force and also friction. The settlement will not be greater than 26cm. The stress and deformation of the pile cap, the abutment, are obtained too. The whole foundation is safe.

Jan 1, 2006

By Murray Gamble

A new type of groundwater cutoff wall has been developed at the University of Waterloo. The Waterloo Barrier? is a steel sheet piling system that incorporates a sealable cavity at each interlocking joint. In order to prevent leakage through the joints, the sealable cavity is flushed clean and injected with sealant after the installation of the piling. The installation and sealing procedures of the Waterloo Barrier? system allow for a high degree of quality control resulting in a very low permeability cutoff wall. Based upon field installations, the bulk wall hydraulic conductivity of the Waterloo Barrier? ranges from 10-8 to 10-10 cm/sec. Recent case histories are presented in which Waterloo Barrier? vertical cutoff walls have been used to prevent the off-site migration of contaminated groundwater or soil gases. In some instances, the Waterloo Barrier? system was used in combinations of applications such as preventing the migration of contaminants, redirecting the flow of groundwater, providing structural shoring for soil excavation and aiding in site de-watering processes.

Jan 1, 1997

By A. F. van Weele

In general cast-in place piles will have an irregular pile shape. However, it is possible that these irregularities are so large that they may lead to pile deficiencies. It is very rarely possible to examine the pile foundations visually. Also the performance of a static or dynamic load test on each individual pile is not practical and much too expensive. This is the reason why pile integrity tests have been developed: to reduce the risk of inadequate pile foundations by performing a simple test. Pile integrity tests are non destructive tests which are carried out after a pile has been installed. Over the years a number of techniques have been developed of which the most important techniques are briefly described in this paper. Of all pile integrity testing methods, Sonic Integrity Testing is the most widely used method in western Europe. This method has been developed by TNO some 15 years ago. Since then the method has been improved, largely due to advances in micro-processing. A major improvement was made by the introduction of digital signal processing techniques. This made the Sonic Integrity Testing method more accurate (smaller defects can be detected), faster (more than 200 piles can be tested on a single working-day) and more reliable (the results are easier to interprete). A few cases will be presented which will show the usefulness of the Sonic Integrity Testing method. In one of these cases, a helpful tool for interpretation of the results is explained: the Sonic Integrity Testing Simulation program TNOWAVE. Notwithstanding the fact that Sonic Integrity Testing is a powerful method, it has also some strict limitations. These will be discussed at the end of the paper.

Jan 1, 1987

By P. B. Kelleher

Most of the piers and other pile-supported marine structures in the New York City Harbor area were constructed prior to the widespread use of currently available pile protective systems. As a result, the support piling of many existing marine structures have experienced deterioration to an extent that their structural sufficiency is impaired long before the useful life of the structures they support is over. This situation presents special and unique problems of how to restore the structural integrity of these piles while at the same time allowing full use of the structures they support. Spearin, Preston & Burrows is a 100 year old New York City-based marine construction firm specializing in waterfront and foundation construction. In recent years it has undertaken and successfully completed several unusual projects in the New York City Harbor area involving the rehabilitation of existing, deteriorated piling underneath major, economically important marine structures. This work was accomplished using techniques that permitted full use of these structures. Several different pile rehabilitation systems were used, each having their own particular application to the deterioration problems of the piles supporting each structure.

Jan 1, 1989

By Z. G. Lin

In Xian, China, compaction by means of soil (or lime-soil) piles is one of the effective methods widely used for densifying loess and eliminating its collapsibility. However, as a result of groundwater table rising, it is no longer applicable in many areas. This paper is the summary of the first-time use in Xian of sand-gravel compaction piles aimed at densifying the miscellaneous fill (already partially under water) and saturated loess at a certain project site. In-situ tests, conducted before and after the treatment and including several kinds of penetration tests backed up and confirmed by a set of plate loading tests, yielded very satisfactory results, strongly testifying to the viability of the method.

Jan 1, 2010

By Benoit Virollet

Over the last 10 years the diameter of unbraced, unlined and unanchored circular shafts has grown dramatically in many parts of the world. This progress has taken place through improvements in: construction methods; concrete rheology; and design capabilities. Excavation equipment has become more precise in terms of operator control and ability to correct alignment of digging elements leading to better alignment tolerances. Also contributing to the increases in shaft diameters is the evolution of design models. A better understanding of soil structure interaction is being incorporated into the analyses in terms of radial soil stresses and imposed loads on the shaft. This paper provides an overview of the recent progress made in circular shaft construction, the primary design considerations, and some innovative uses of efficient arc elements to develop unsupported structures of other shapes. In addition, a summary of recent circular shafts constructed worldwide is provided.

Jan 1, 2006

By Shaw-Shong Liew

This paper presents the processes of investigation, analysis, design, construction and monitoring of soil nail stabilisation work to facilitate a 14.5 m deep excavation at an uncontrolled fill ground. An extensive instrumentation programme had been implemented to monitor the performance of the stabilisation solution, to provide validation for the designed nail resistance and groundwater variation. From the monitoring results, it was proved that the soil nail stabilisation technique is effective for loose saturated fill provided that substantial care is taken during implementation. Construction difficulties, solutions to overcome the problems and lessons learned will be discussed in the paper.

Jan 1, 2006

By Gang Guo, Zhong Liu, Yi Zhang, Jingchun Lu

"Abstract Application of soil displacement screw pile (known as SDS pile) has been experiencing accelerated growth in Chinese deep foundation industry because of its technical advantages, environmental benefits, and cost effective as well. As bored displacement piling, SDS piles are able to perform better than non-displacement piling such as CFA plies due to changing the stress state in the soil around SDS piles during the installation. Therefore the design methods between the conventional pile type and SDS pile type have some differences. Based on the methodology research, current Chinese piling rigs, displacement augers and piling projects are introduced, and the current design approaches for SDS piles in China are also described. Moreover, the design results are verified by using full scale load tests, and a part of the research results of SDS piling system acquired in China are presented.IntroductionThe Continuous Flight Auger Pile, also known as the CFA pile, has occupied about 22% in the pile market all over the world (Van Impe, 2004; Bottiau, 2006). The CFA piles are usually used for large diameter (600mm~1200mm) pile foundations and deep excavation projects. Whereas the small size CFA piles (400mm~500mm) are mainly applied for composite foundations in China. In the past 10 years, the new technology of soil displacement screw piling has been applied worldwide (Prezzi et al., 2005). And it is also extensively used for high-rise buildings, industrial plants and railway projects in China (shown in Figure 1)."

Jan 1, 2014

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

By Bengt H. Fellenius

Session 2, Deep Foundation without Soil Excavation, has attracted no fewer than 22 papers dealing with subjects from soil improvement by grouting, injection, and deep mixing techniques through vibroflotation and special piles, including aspects pertaining to conventional driven and bored piles. In the short time available, it is not possible to both do justice to the papers and provide a critical review of the state-of-the-art. Instead, to meet the objective of making the next half hour worthwhile to the audience, I have chosen to comment on a few special points brought forward in the papers and thereafter to discuss more in detail a couple of aspects I have deemed to be of general interest. Four papers deal with jet-grouting, injection, and deep mixing techniques: DOMSKI, J. J. Reinforcement of subsoil under the foundations of historical buildings in Cracow using deep injection technique. RESTELLI, A. B, BERTERO, M., and LODIGIANI, E. Deep mixing technology to improve the bearing capacity of a very soft clayey soil under an earth embankment.

Jan 1, 1994

By Peter J. Nicholson

Since the reintroduction of soil mixing to the United States over 10 years ago, the work installed by soil mixing technology has grown dramatically. From an annual turnover of less than ten million dollars per year the volume of soil mixing put in place has grown to an estimated $40 million per year in the year 2000. The majority of work done to date has involved walls, either for excavation support, permanent retaining structures or hydraulic cut-off walls. The other major use for soil mixing has been for mass stabilization of soils whether for isolation of contaminants or for retaining structures. This paper will discuss the uses of and costs of typical soil mix structures. BACKGROUND Soil mixing is defined as the in-situ combining of reagents, typically cement, with native soils, the purpose being to modify or improve the ground. This history of soil mixing covers only the use of cement slurry, aggregated with soil in-situ by mechanical mixing methods only. Soil mixing by use of high-pressure hydraulic means, also known as Jet Grouting, will not be discussed. In addition this will not cover ex-situ (above ground) mixing, or mixing dry reagents with soil. Only mixing applications for building, civil and heavy construction applications will be discussed, with only passing reference made to uses of soil mixing for environmental remediation work.

Jan 1, 2001

By Maurice Bottiau

"Abstract When addressing the performance of deep foundations, many parameters play a role, from adequate soil investigation to performance monitoring and testing. The correct understanding of pile construction, though, remains crucial. After a long period of empirical design and regulations, the last decades have been the ones of theoretical considerations and extensive codes writing. The interaction between technology and design, however, still plays a determinant role. The introduction of hydraulics and the exponential increase in available power on one hand, the miniaturization and the introduction of electronics in control and monitoring systems on the other hand have exerted a major influence on new foundation systems or the evolution and control of existing systems. It appears important to try to take execution related parameters and their control during execution more deeply into account when assessing the final result of the deep foundations and the achieved level of safety and reliability. In this contribution, we will try to analyze how systems, equipment and pile production monitoring and testing can influence the pile performance, and if/how this influence could/should be translated in adapted safety or installation factors. This analysis will run through different categories of piles: driven, augercast and displacement auger piles and bored piles. INTRODUCTIONThe global performance of a deep foundation depends on different aspects (Poulos, 2003):1. Ground investigation2. Design and analysis3. Construction4. Testing5. Performance monitoring6. Remediation and performance enhancementThis paper intends to address the importance of pile construction and the control of it on the final performance of the pile-group of piles. There has been an increasing interest for theoretical analysis over the last 20 years, followed by an increasing impact of regulation and codes. Without denying the importance of the latter, the author wants to point out how installation procedure and project specific parameters can largely influence the reliability of the deep foundation. In this context, detailed and prescriptive standards can miss their objective of intended improvement of accuracy and reliability, but even worse they can adversely impact engineering judgment. In today’s construction world, it is possible to gather installation information which can be of outmost importance for the final deep foundations performance. Therefore, the increase or decrease of installation reliability through adequate pile testing and performance monitoring should be emphasized and should be taken into account in the codes. This is the case already in most advanced codes, but in a limited and insufficiently refined way. After reviewing how codes deal with this issue today, we will show some recent examples of unexpected results due to pile installation. We will try to put these examples into a broader perspective by highlighting some reference and/or recent literature considerations. Finally we will try to summarize how pile testing and installation documentation can increase reliability and attempt to open the debate on how codes could/should allow for more engineering judgment."

Jan 1, 2014

By Mike Fabius

The Lakehead Region Conservation Authority is responsible for slopes along the Kaministiquia River, one of the largest tributaries to Lake Superior in Canada. After arresting toe erosion for a mile of riverbank, the remainder of the slope required stabilization to stop further crest regression and to protect the houses, street and services at the top. Stabilization of the 100 ft. high slope was tendered as design-build with a target safety factor of 1.3 and a design life of 75 years. The successful bid was a system of 1.4 inch diameter soil nails up to 40 feet long, installed perpendicular to the slope on a 3 to 5 foot grid. The conventional shotcrete facing was replaced with a ?green? biotechnical facing and special transverse plate heads on the nails. The key to keeping costs low proved to be installation with light equipment working on the slope, and driving the nails without drilling or grouting. Rather than tension, the design was based on bending in the nails, similar to a laterally loaded flexible pile. The paper describes the design and installation of this innovative system. The design is discussed in terms of soil properties, nail resistance as it varies with depth, failure modes, corrosion protection, root design and nail head design. Construction challenges are discussed. The system is compared to an adjacent anchored soldier pile wall built along the same slope 20 years ago. Post construction monitoring results confirm predicted performance.

Jan 1, 2006

By Howard A. Perko

Soldier pile and lagging is a conventional means of temporary excavation shoring. Timber lagging design has traditionally been based upon the designer's experience or empirical rules. One such method is the Goldberg Zoino chart used by the Federal Highway Administration. Most of these methods restrict the designer to a consistent soil profile, certain pile spacing, construction grade timber lagging, and limited depth. The methods do not take into account surcharge loads or a variety of other factors that could arise. A designer working outside of ordinary circumstances with unusual loads, varying soil conditions, or alternate lagging materials has difficulty estimating lateral earth pressures. In rigid earth retention systems, lateral earth pressure is generally assumed to be constant along the length of the wall. In soldier pile and lagging systems, the lagging is often considerably less stiff than the steel soldier piles. As the lagging deflects, the soil tends to bridge between the stiffer elements resulting in a lower pressure on the lagging. Several previously published methods by others for determining this reduced pressure are summarized and discussed. These methods typically consist of using a portion of the active earth pressure in several different pressure distributions. A simple theoretical model is presented for determination of lateral earth pressures on wood lagging. The model is based on a three-dimensional "silo" shaped sliding wedge analysis. Results of the model are compared with other published methods. The model compares well with these methods which cover the normal spectrum of design situations. In addition, the model can be used to estimate lateral earth pressures outside typical situations.

Jan 1, 2008

By George J. Tamara

The urban environment presents special challenges for the design and construction of earth retention systems. Complications arising from difficult subsurface conditions are compounded by the presence of urban infrastructure and existing and prior construction. The proximity of adjacent structures as well as intense prior use can cause special concerns including the potential for archeological artifacts or contaminated ground or ground water. Utilities and structures may be particularly vulnerable to the effects of ground movement, dewatering and vibrations. Difficulty of access, congestion and limited work areas may severely restrict means and methods of construction. Dewatering may be limited or prohibited because of concerns for disposal of clean or contaminated water, depletion of aquifers, drawing of contaminants to the site or dewatering induced settlements.

Jan 1, 2003

By A. J. Partos

One Liberty Place, at 315 m is the tallest building in Philadelphia, PA USA. It is supported on drilled piers socketed in heterogeneous rock. 3832 kN/m2 end bearing and 383 to 766 kN/m2 shaft resistances were selected. Design load distribution was 40% on the base and 60% by shaft resistance. The maximum compression on the corner core columns is supported by clusters of 3 drilled piers. In order to confirm load distributions along shaft and at the base, Drilled Pier G-10 supporting T13-A type outrigger column was instrumented. This column supports 53,849 kN compressive load which includes 13,440 kN windload. This paper reveals details about the process to select the final design for One Liberty Place together with pertinent Information about site geology, foundation construction, quality control, and methods of steel erection. It also presents detailed Information on the type of Instruments, their calibrations, field fabrication, and installation in the shaft of Pier G-10. Readings of concrete temperatures, computed loads, and load distributions are presented for a period from October 1985 through May 1988. The building was completed in 1987.

Jan 1, 1989

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: piles near and within embankments, piles near an excavation for a pile cap, and piles subjected to seismic ground motions.

Jan 1, 2006

By Guo H. Lei

Over the last four decades, barrettes have been ever-increasingly adopted as the foundations for tall buildings and heavy infrastructure projects all over the world. Many findings have been gained from practical applications and theoretical researches. In this article, a collection of literature is reviewed on the installation effects and load-carrying behaviour of barrettes derived from field and laboratory tests and theoretical studies. It covers many aspects, such as the ground deformations and stress changes caused by the installation of barrettes, the shaft resistance mobilisation behaviour, the construction effects on the shaft resistance, and the effects of pile spacing, pile shape and pile group layout on the load-carrying behaviour of barrettes.

Jan 1, 2006

By Andy Schroeder

Located in Hamilton, Ontario Canada, Berminghammer Foundation Equipment, is a manufacturer of advanced foundation equipment with 30 years of experience. The company is represented in more than 20 countries world wide, maintains an extensive Research and Development team, and has earned a reputation for finding the most practical solutions to the most challenging projects. The vertical travel lead, referred to as "VTL" system, was first developed and patented by C.W. Bermingham in the 1970's. This lead system was developed in response to the fundamental limitations of either a fixed lead or hanging lead system. The fixed lead system is well suited to level job sites with few obstructions and has the advantage of faster positioning of the lead, the hanging lead is very adaptable to different elevations and batter piles but takes much longer to position. Therefore the Vertical Travel Lead was developed to combine the advantages of fixed leads, fast and accurate positioning, with the ability to adjust the height of the lead base up or down. The VTL lead is connected to the boom by a sliding connection which allows the lead to be elevated or lowered below grade. The advantages of the VTL system were recognized by many foundation specialists and they have become the Industry standard in Canada , US Railway Construction , and many parts of the USA.

Jan 1, 1997

By Peter J. Nicholson

A new method of constructing retaining walls, in-situ, prior to excavation has been developed. This "Vertical Earth Reinforcement Technique" VERT, has been demonstrated at a full scale test wall at the National Geotechnical Experimentation Site at Texas A&M University. This 10 meter high wall, was constructed of elements of soil mixing in an array that forced composite behavior between the soil mixed elements and the in-situ soils. Inclinometers and extensometers were used to verify the performance of the wall. The construction and results of the testing are presented.

Jan 1, 1998