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By Karsten Beckhaus

"Abstract Tremie concrete for special geotechnical works needs special properties, especially during the casting process. Today’s execution standards for bored piles and diaphragm walls, EN 1536 and EN 1538, as well as the draft version of concrete standard EN 206, all comprise regulations for deep foundation concrete which have not been changed for decades. Considering the recent development in concrete technology at the same time and its actual state-of-the-art, it is essential to develop new normative specifications and specification requirements.GeneralTo allow the required integrity and quality after placing and hardening, concrete for structural elements like bored piles or diaphragm walls, used as foundations of high-rise buildings or as retaining structures for large and deep building pits, must have adequate workability and stability.In addition to requirements on mechanical properties and on durability, both of which have increased within the last decades, concrete must be suitable for being cast in deep or extremely deep excavations, see figure 1. Today’s specialist foundation engineering machinery makes it possible to drill or cut down to in excess of100 m depth. Concrete technology has developed and allows the use of high performance concrete for deep foundations. But is this capability represented by actual regulations?It has become very common for the industry to supply or use concrete with low water cement ratios, nevertheless highly flowable and set-retarded for several hours if needed. Very low water cement ratios allow design strength of 60 MPa or higher (Larisch, 2011), and a very low porosity which is required for a long service life in aggressive conditions, e.g. by chlorides.To achieve best performance, it is obvious that the concrete must completely fill the excavation and fully embed the reinforcement. As vibration of deep foundation concrete is (usually) not allowed and was anyway inefficient, deep foundation concrete must be designed to self-compact under hydrostatic pressure. Generally, it must be considered that after placement the concrete’s quality cannot be influenced anymore. Therefore, both the pouring procedure and the concrete quality must be adequate."

Jan 1, 2014

By Jouko L. Lehtonen

Sheet pile walls can be sealed watertightly using various methods. The objective of this paper is to introduce a new innovation comprising the use of continuous cement grouting during embedding. The method has been tested on a field test site and installation and permeability features have been observed and analyzed. Installation can be carried out using traditional sheet piling machinery, merely some additional grouting equipment is needed. Installation speed of grouted sheet piles corresponds to that of conventional embedding. The permeability of the tested method is satisfactory in applications where e.g. polluted soil or water has to be isolated from the surrounding environment. In addition, this method can be used for conventional retaining walls where very low permeability is required or for reduction of soil vibration, e.g. close to a railway embankment. The new method to grout simultaneously and continuously during embedding has been developed based on respective innovations on impact driven steel piles.

Jan 1, 2006

By A. Lyndon

Vertical and lateral load tests were carried out on two 13 m deep bored cast-in-place instrumented piles, socketed into weathered sandstone. The first pile, 1200 mm in diameter, was loaded vertically to a maximum of 16000 kN and then loaded to failure under lateral load (1900 kN). The second pile, 1500 mm in diameter, was tested under lateral load up to a maximum of 2400 kN. It was found that the deflections of the 1200 mm pile were more than twice those of the 1500 mm pile under similar loads. The soils on the site are not easily tested in the laboratory, or by conventional insitu site investigation techniques, parameters needed in design can only be reliably obtained from pile test results. In this report shear moduli are back analysed from the vertical load test and the two lateral load tests. For these similarly installed piles very different design parameters were determined from the lateral load tests, the only known major difference between the piles being that the 1200 mm pile was loaded vertically before it was loaded laterally. Changes in G values needed to match performance under vertical load if applicable to lateral loading could have accounted for a significant amount of the difference.

Jan 1, 1989

Jan 1, 2001

By Tom A. Armour

Different variations of soil nailing techniques have been used in the United States since the late 1970's. Such techniques owe their origins to French developments, which began in the early 1970's as a spin-off from European tunneling excavation support practice. The growing demands of urban infrastructure development and rehabilitation and environmental protection have created an active and expanding soil nailing market demand for earth retention and slope stabilization in the United States since its early developmental years. There is a clear need for a fundamental review of the large number of soil nailing techniques that are currently being used in the United States. Following a brief summary tracing the historical development of soil nailing and a generic classification of applications, this paper provides a review of the different recent advances in the design and construction of soil nailed systems. Discussion topics include nail design advances, permanent "top-down", structure support/underpinning, alternative face stability measures, composite systems, hollow bar and fiberglass nails and architectural reinforced concrete/shotcrete facings. Case histories will be presented to illustrate each of these advances.

Jan 1, 2003

By Robert E. Fosse

Driven 14-inch-square concrete piles were used as the foundations of Genentech Hall at the new University of California, San Francisco Mission Bay Campus. The five-story, steel eccentrically-braced frame building is currently under construction at a 43-acre property located in a former large shallow marshy inlet from San Francisco Bay. The piles were driven through 10 to 25 feet of fill and 20 to 60 feet of soft compressible Bay Mud into an underlying dense sand layer. Pile design capacities were developed for traditional allowable stress design, load factor and resistance design, and ultimate design criteria. The ultimate level capacities were for checks of loads occurring when the links in the eccentrically-braced frame yield during an earthquake. A load test program was performed to confirm pile design recommendations. Two test pile locations were selected for compression, tension, and lateral load tests to evaluate pile capacity and pile/soil stiffness under long-term, short-term and rapid loading conditions. Maximum test loads were 1000 kips downward, 350 kips uplift and 50 kips lateral. Foundation construction began by driving 34 indicator piles with a Delmag D46-32 diesel hammer of 113 foot-kips maximum rated energy. All indicator piles were monitored during initial driving using the Pile Driving Analyzer. Restrike data, obtained several days after initial driving, indicated significant pile-soil setup and typical pile capacity increases from 750 to 1000 kips. The majority of the 1242 production piles were then driven to acceptance criteria of 75 blows per foot and a minimum embedment of 10 feet into the dense sand bearing layer. Piles driven to full length without achieving the blowcount criteria were evaluated on a case-by-case basis. Acceptance of these piles was established by evaluating restrike data.

Jan 1, 2002

By D. R. Dance

The Resonant, or as it has more commonly come to be known the 'Sonic' Pile Driver, dates back to the early 1960's, when prototypes were produced by Charlie Guild, of Providence, Rhode Island, and A1 Bodine of Los Angeles, California, these were later to be developed into the unit known as the BRD 1000. Based on this initial work, the Shell Oil Companies of Sonico and The Resonant Pile Corporation, produced and operated 30 of these BRD 1000 machines, which were used throughout the U.S.A. and Canada on a wide range of foundation projects. Subsequent to this, Raymond International and G K N, of England, operated units on programs; the G K N units being of slightly modified configuration. In 1973 Hawker Siddeley Canada Ltd., acquired the license for the Pile Driver and related systems with the intent of promoting the use of the machines to install support pilings on the Alyaska Pipeline Project, but this did not materialize due to problems with the oscillator. After radical redesign and field testing of the oscillator system the unit was employed on a number of test projects principally in Northern Canada and Alaska.

Jan 1, 1987

By B. Ladanyi

The design philosophies for piles in unfrozen and frozen soils are compared, and their similarities and differences are underlined. It is shown that in frozen soils, the long term behavior of a pile is difficult to predict, because of inadequate knowledge on the behavior of adfreeze bond with time, and on the value and variation of the lateral normal stress acting on the pile. Both of these problems are discussed in the paper on the basis of laboratory tests and theoretical analyses.

Jan 1, 2010

By Cristhian C. Mendoza, Renato da Cunha, Bernardo Caicedo, Max Barbosa

"Abstract This paper shows that a raft alone is not sufficiently appropriate to address the uncertainty of underlying soil variability; therefore, a piled raft system is a better option for mitigating such uncertainty. To study the variability of soil, the behavior of the Piled-Raft Foundation was analyzed with a type of self-drilling micropiles: the ""Alluvial Anker"" (common name for this pile type in Brasilia city). These micropiles have been used in the city and have the advantage that the drill pipe also serves as reinforcement. The studied parameters belong to an elastoplastic constitutive model for strain-stress analysis of soil; variability of these parameters can be intrinsic and/or epistemic. Simulations were performed for a hypothetical Piled-Raft Foundation subjected to vertical loading using the random finite element method. The average parameters of the constitutive model were obtained through laboratory tests. The simulations of the load test were compared with results of a real scale experimental test conducted exclusively for this work in the field. It is analyzed the relative importance of the variability of some geomechanical parameters and their variation with depth is considered. In addition, it is discussed a comparison between the uncertainty of the geomechanical parameters and the uncertainty of the results of the vertical loading test. Finally, this paper shows that a decrease of the safety factor may occur when taking into account the variability of the parameters.IntroductionBrasilia is located in a highly weathered residual tropical soil (lateritic & latossol on pedogenetic concepts). This soil presents high content of alumina and iron due to the lixiviation process of the upper layers. As a consequence, the cemented structure is highly unstable and it can generate strong changes of volume (i.e. collapse) due to changes in both moisture and state of stresses. Therefore, a greater understanding of the construction of Piled-Raft Foundation systems on this particular soil conditions is needed – especially because it covers more than 80% of the surface area of the Brazilian Federal District.Thereafter, this work investigates the influence of the variability of the soil parameters over the uncertainty of the Piled-Raft Foundation design. The studied parameters belong to an elastoplastic constitutive model for strain-stress analysis of soils. The simulations were performed for two hypothetical Piled-Raft Foundations subjected to vertical loading by using the stochastic finite element method. The results were compared to real load tests in Piled-Rafts with “Alluvial Anker” pile types."

Jan 1, 2014

By Derek J. Lennon

Ground conditions in central Glasgow generally comprise loose granular deposits overlying stiffer soils. CFA piling would normally be preferred for urban sites in these ground conditions, but flighting of the superficial deposits has on occasions resulted in building damage. Over the last five years rotary bored piling with vinyl polymer support fluid has proved to be an economic alternative to bentonite slurry. Two case histories in central Glasgow are described in this paper, one for piles founding in granular soils and one for piles founding into bedrock. A comparison is made between the methods required for disposal of the liquid waste from bentonite and vinyl polymer slurries.

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 Jorj O. Osterberg

Until ten years ago, the largest load tests on drilled shafts (bored piles) were about 3,000 tons (27MN). These tests were made with kentledge (large weights, usually concrete blocks) stacked up as a reaction to the applied downward load of a hydraulic jack. In some cases, the jack load is resisted by a load frame held down by piles or anchors connected to the frame. When the test loads exceed 3,000 tons (27MN), these methods become cumbersome expensive and time consuming. The Osterberg (O-cell) test method does not require any reaction load. It has become the only cost effective method for static load testing of high capacity shafts. Over 650 load tests have been performed with this method, 86 of which were over 3,000 tons (27 MN) and 40 over 5,000 tons (44 MN), and the largest test load was 17,000 tons (150 MN). Tests have been made on sands below the water table, shafts ending in rock sockets, and cemented sands and gravels. Test results and details for selected load tests are discussed.

Jan 1, 2002

By Francis J. Arland

The installation of augered cast-in-place (ACIP) piles requires careful quality control to assure a successful pile installation. Unlike steel, pre-stressed concrete or other types of driven piles, which are shop fabricated, delivered to the site and typically driven to a minimum tip resistance, augered cast-in-place piles are installed to a pre-determined tip elevation or to a refusal criteria. The structural section of the ACIP pile is constructed during pile installation and cannot be inspected prior to installation. Therefore, a carefully administered quality control program is essential to a pile foundation that will meet or exceed design requirements. This requires an experienced team consisting of the Geotechnical Engineer, Contractor and Inspector. The focus of this paper is to discuss the responsibilities and duties of the ACIP piling Inspector. Qualifications of the Inspector The qualifications of the inspector are related to the complexity and difficulty of the proposed project. Ideally, the Inspector should be an individual with a degree in civil engineering with special emphasis in geotechnical engineering. A properly trained technician with geotechnical engineering experience working under the direct supervision of a geotechnical engineer may be able to provide competent inspection on some projects. It is important that the Inspector have a good understanding of subsurface and ground water conditions and how they will affect pile installation. The Inspector must understand ACIP pile installation procedures and be able to communicate with the Contractor, Structural and Geotechnical Engineers; and maintain a detailed pile record for each installed pile.

Jan 1, 1997

By W. Lum

In the U.S., flexible metal pipe culverts are designed by ring compression theory because the pipes are capable of deflecting and deriving side support from surrounding ground. For economy, tunnel liners are often designed as flexible structures that depend on the lateral pressure of the surrounding ground to maintain stability. In this paper, simple formulas are presented to determine the maximum deflection a concrete tunnel liner may assume and the ring compressive strength of the deflected liner. A tunnel can then be constructed to work within these limits. Similar techniques may be used to design concrete pipes.

Jan 1, 2010

By Rudolph P. Frizzi

This paper presents different deep foundation systems and associated settlement records for high-rise building projects in the coastal areas of southeastern Florida. An introduction to the sedimentary soil and soft rock geology in coastal areas of southeast Florida is presented, and the deep foundation systems utilized include: piles of varying length, pile supported mat, preload and short piles, and drilled shafts. The implementation and associated settlement monitoring data of the different deep foundation systems are described through case histories involving 20 to 66-story buildings. In addition, the deep foundation systems and settlement monitoring results for twenty-one additional high-rise building projects in the coastal areas of southeastern Florida are presented.

Jan 1, 2003

By E. Stoetzer

In all known deep mixing processes the existing soil is mixed with self hardening slurry by mixing tools that rotate about a vertical axis (augers, mixing paddles). Wall panels are constructed using sets of multiple mixing tools combined into a single unit. These techniques have been developed on the principle of the rotary drilling technology. In contrast, the new Cutter Soil Mixing or CSM technique is derived from the cutter technology. The soil is loosened and broken down by cutter wheels, then mixed in-situ by the rotating cutter wheels with the self-hardening slurry - introduced into the ground between the two wheels - to form a soil-slurry mortar. The main area of application lies in the construction of cut-off and retaining walls.

Jan 1, 2006

By Jiwei Duan

The deformation and load transfer behavior of a single soil-cement column are studied with the finite element method. The results show that there is an effective length for a soil-cement column. Beyond this length, the settlement of the column is approximately equal to a constant. The effective pile length is introduced to the concentric cylinder approach (Randolph and Wroth 1978), and an analytical formula for estimating the settlement of a single flexible pile is presented. A second analytical formula for determining the effective pile length of a soil-cement column is obtained and an example shows that the calculated and measured results are in quite good agreement.

Jan 1, 2002

By Donald J. Murphy

Longevity of structural units, as compared to the planned useful life of a facility, always is a design consideration. Typical concerns include slow decay due to environmental factors, and changes in constitutive relationships governing the performance of the material involved. With respect to foundations, the usual items of interest are corrosion of steel and concrete, and time dependent behavior of the soil/structure system. For piles, as with other foundations, deterioration is precluded, mitigated or otherwise accounted for by assessing properly the ambient situation (sulphates, pH, stray currents, resistivity) and providing safeguards, such as resistant construction products, oversizing, coatings, and/or cathodic protection. On the other hand, long term performance of the pile foundations, as affected by time dependent characteristics of the supporting soil or rock, can be predicted and controlled only with a synergetic coupling of analyses and field tests. The history of a project for which this approach was followed forms the basis for this paper.

Jan 1, 1986

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By Sridhar Krishnan

This paper presents the results of a comprehensive pre-production pile testing programme for the US$ 800 million 1400MW Coal-Fired Jimah Power Plant Project in Negeri Sembilan, Malaysia. The testing programme included high-strain dynamic testing and fully instrumented static axial and lateral load testing of driven prestressed concrete piles and bored cast-in-place piles. A highlight of the testing programme was the pioneering use of the Global Strain Extensometer (GloStrExt) Method, a deformation monitoring system that uses advanced pneumatically- or hydraulically-anchored extensometers and a novel analytical technique to monitor loads and displacements down the shaft and at the toe of driven prestressed concrete piles. The experience with the testing programme for the Jimah Project also demonstrates the possibility of achieving notable breakthroughs, not only in the monitoring, evaluation and reporting of pile foundation behaviour dynamics but also in our understanding of the mechanisms that underpin such behaviour. These significant gains are undeniably a direct result of the committed and co-operative relationship among the project owner, design/builder, specialist piling subcontractors, pile suppliers and pile instrumentation and testing specialists.

Jan 1, 2006