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By Eric S. Lindquist

High groundwater levels combined with variable soil and rock profiles present challenges to the design and construction of deep excavation support systems. Increasingly, secant piling techniques are the preferred technical solution for shoring in these cases. Recent developments in drilling equipment, tooling and procedures allow cost-effective construction of deep, overlapped pile systems to tight tolerances in extremely difficult ground conditions. This paper summarizes critical design considerations for secant pile shoring systems, detailing recent advances in installation procedures and verification techniques that allow secant piles to be used for an expanding range of project conditions. Technically- and commercially-viable secant pile shoring designs require that stringent drilling tolerances be achieved in order to successfully provide combined structural support and groundwater cutoff systems, particularly for unreinforced circular secant pile shafts acting in ring compression. Modern drill rigs and tooling can advance fully cased shafts in geotechnical conditions which range from cohesionless soils below the groundwater table to hard rock, within a single drillhole. Down-hole instrumentation provides verification that tolerance requirements are met and allow secant pile shoring to be used at sites previously considered unacceptably risky. In California, secant pile shoring systems are being used for excavation depths of over 100 ft (30 m) on projects with challenging site conditions. Two case studies are presented detailing severe geotechnical conditions and excavation depths which represent the regional state of practice in secant piled excavation support. These projects provide real world examples of the design, construction and construction verification techniques that permit secant pile shoring to be used in more demanding geotechnical conditions and to greater depths than ever before.

Jan 1, 2011

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 However, as a result of groundwater table rising, it is no longer applicable in many areas.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 J. Matos e Silva

The paper refers five examples of executed diaphragm walls with one to five levels of anchorages. For each example a comparison is made between the results of the design using the traditional criteria and the Eurocode 7 recommendations. A comparison is also made with the behaviour of the diaphragm walls during the construction phase. From the referred examples the author presents his conclusions.

Jan 1, 2002

By Mary C. Nodine, Michael P. Walker, Paul Eggers, Donald E. Aubrecht

The CANALSIDE commercial development in Buffalo, New York serves to revitalize the former site of the Buffalo Memorial Auditorium, adjacent to Lake Erie. The Auditorium was constructed in 1940 and founded on steel H-piles driven to limestone bedrock. After decades of professional sport and entertainment events, the “Aud,” as it was locally known, was closed in 1996. It sat vacant until it was demolished in 2009, at which time plans were made to revitalize the area with shops, restaurants, and a historic replica canal. The only portion of the Aud that was left intact was a subbasement boiler room. The subbasement was renovated in 2014 and has since been used to house water and ice making equipment for the historic replica canals, which boast recreational ice skating in the winter. The subbasement floor was about 10 feet below groundwater and the Lake Erie water level. The floor consisted of an approximately 4-foot-thick layered inverted waffle slab system, with reinforced concrete grade beams and concrete infill between the grade beams. A waterproofing membrane was located near the base of the slab. There were no major seepage issues in the subbasement, so the existing waterproofing membrane was assumed to be intact and performing adequately. A four-story building housing a children’s museum was proposed to be constructed directly above the subbasement. The loads imparted by the new building would exceed the capacity of the existing piles, so it was determined that drilling micropiles through the subbasement floor would be the most practical means of supporting the new building. Drilling through the existing slab and waterproofing system was a concern due to the challenges of controlling water during construction and the importance of maintaining the integrity of the permanent waterproofing system.

Jan 1, 2018

By Kent C. Werle

This brief discusses the installation and application of sleeved piles of two different types for two different projects, the W, Seattle to Harbor Island Swing Bridge Project and the Seattle Access Project. A description of these relatively novel piling systems is given, as well as some notes on their installation and application. As implied by the term "sleeved" these are piles which consist of two piles, an inner pile combined with an outer concentric sleeve pile. Background, Swing Bridge The Swing Bridge project is virtually unique in the world in that it is a "lift and turn" swing bridge. It is also a concrete, cast -in-place segmental bridge which is designed to be moveable.

Jan 1, 1990

By Miklós Kovács

A new type of the cast in situ piles is introduced. The installation of the new pile is based on a pushing in/gaining back procedure. A temporarily closed tip element with square shaped cross-section being attached to an upper circular shaft tube is vibrated into the soil. The steel armature is embedded. Concrete is poured into the tube and, the whole structure is gained back while the tip is in opened position. The width of the tip is less than or equal to 40 cm. The maximum length of the pile is about of 14 m. Great bearing capacity is resulted from the double soil compaction effect. No spoil is generated and, the pile construction can be controlled. The paper presents the results of four loading test at three sites with some soil data.

Jan 1, 2002

By Dario Libano

"The Line 5 Extension, in Sao Paulo, Brazil, is currently the most important investment in public transportation by Sao Paulo’s state government. It will connect the south part of the city to the city center, crossing through four other major Metro lines and stations; all currently in operation. The total extension of the line is 11 km (6.8 mi), and includes a new parking yard for the trains and 11 new stations. The Brooklin Station, one of the new stations due to be open and operating in 2016, has a unique geometry of five secant shafts.The original design included constructing five secant shafts stabilized by two plastic slurry walls using conventional grab technology. One slurry wall, along the Santo Amaro Avenue, was to contain the contamination plumes, and another was for temporary support to enable the excavation of the shafts. The final retaining wall design was changed to a concrete structural diaphragm wall that reduced the construction time of the shafts by half, allowing the contractor to meet the construction schedule. This solution also avoided dewatering effects in a geological region characterized by Quaternary sediments and environmental contamination plumes. It was the first time that a hydromill was used in such a situation in Brazil. The hydromill, by overcutting the panels, increased the quality of the joints, and decreased the probability of having seepage into the shafts. The hydromill also created a seepage barrier and avoided movement of the contaminated plumes.The GeologyLocal geology is composed of a superficial Quaternary soil, basically soft organic clays and sands and gravels. From the depth of 8 m (26 ft) until 18 m (59 ft), geology is composed by tertiary medium compact sand with thin silt-clay layers. From 18 m (59 ft) down, there are alternations between compact silt-sands layers with very hard clays layers. Each is approximately 5 to 10 m (16.4 ft to 33 ft) thick.The Initial Basic DesignThe original basic design of the Brooklin Station was to be constructed from five 40 m (131 ft) diameter intersecting circular shafts, all in a line along the axis of the Metro tunnel, in 555 days. In the excavation sequence, the odd shafts were first excavated, waterproofed and had part of their inside cast-in-place structure built before the even shafts were excavated. During the excavation of the even shafts, part of the odd shaft’s support was demolished and connected with the even support. A 0.8 m (2.6 ft) thick plastic slurry wall, acting together with the wire mesh reinforced shotcrete support, ensured the excavation stability around the five shafts."

Jan 1, 2014

By A. E. Fiorato

A test program was conducted to evaluate use of high-strength concrete in drilled shafts (caissons). The objective of the program was to determine if internal temperatures developed during cement hydration, or other characteristics of high-strength mixes, affect in-situ strength and stiffness. This paper covers strength results. Two 10-ft (3.0-m) diameter by 40-ft (12.2-m) deep caissons were constructed using two different commercially available high-strength concretes, a "low-heat" and a "high-strength" mix. Measured 6x12-in. (150x300mm) moist cured cylinder strengths at 56 days were 13,690 psi (94 MPa) for the "low-heat" mix and 17,130 psi (118 MPa) for the "high-strength" mix. Compressive strengths and moduli of elasticity of cores taken from the caissons were compared to those of companion cylinders made during casting of the caissons and stored in a moist room. Strengths of 4x8-in. (100x200 mm) cores taken at four ages and tested between 34 and 398 days averaged 81% of strengths of 6x12-in. (150x300 mm) moist cured cylinders at corresponding ages. In-situ (core) strengths of the caissons did not appear to be measurably affected by temperature. However, the data indicate that core strengths were sensitive to level of consolidation, as reflected in entrapped air voids. Overall, the results indicate that high-strength concretes can be used in drilled shaft (caisson) foundations.

Jan 1, 1991

By Peter J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 1991

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

Jan 1, 2002

By W. H. Liu

The stability of floors of large drydocks and wagon tipper sheds at coal terminals is an important matter but quite difficult to solve. Anchors can be used to join floors to foundations thus ensuring the stability of floors by the self-weight of floors and the pull of anchors. In this paper, the author describes the structures and types of the anchors used in the floors of the drydock in Beihai Shipyard and the wagon tipper shed at Shijiu Port, both in Shandong Province China, the determination of bearing capacity of anchors in rock bed of highly weathered granite, the comparison between prestressed anchors and non-prestressed anchors, the construction technology of anchors and the analysis of field experimental data.

Jan 1, 2010

By Yu Zhenquan

At the construction site of Bao Shan Iron &. Steel Mill in Shanghai, lots of RC driven piles with length of 50 to 60m were applied. The most unfavourable distribution of stress along the pile shaft was known by measuring the compressive and tensive stresses. With analysing the test results a phenomenon of impact fatigue of RC pile was discovered, the range of impact fatigue and its critical zone can be distinguished. Finally some countermeasures are presented to avoid the impact fatigue of RC long pile.

Jan 1, 1991

By Dario Libano, Luis Carlos Tenuta, Juliano Penteado

"Subway Line Number 4 is one of the newest additions to the Rio de Janeiro subway network. Built for the 2016 Olympic Games, the 16 km (10 mi) subway line connects the south of the city, with the famous beaches Copacabana and Ipanema, to Barra da Tijuca, west of the city, where the Olympic Village and Park are located. This new line, which is estimated to cost USD 2.2 billion, is composed of six new stations: Jardim Oceanico, São Conrado, Gavea, Antero de Quintal, Jardim de Alah (JA) and Nossa Senhora da Paz Station.Brasfond participated in the construction of foundations and retaining structures for all the stations, and each presented unique challenges. This is not surprising considering the difficulties present in a highly-dense urban environment including utilities, nearby buildings, traffic limitations and noise.Of all the stations, JA Station was the most challenging to construct. It was located in the middle of an avenue between residential high rises supported on shallow foundations as well as below sea level in sands with high groundwater. The other five stations were located in small parks and squares, with no buildings in the immediate proximity.The interaction between designer, owner, and the general and foundation contractors during execution was key in safely reducing the construction schedule. This was significant given the unforeseen construction delays the client, Linha 4 Sul JV, faced due to permitting, utility and traffic relocation so that the owner could fulfill their final goal: making the line operational by the Olympic Games. The GeologyGeologically, the state of Rio de Janeiro is formed by Pre- Cambrian crystalline basement rock. Its geological formation is very old and comprises two major orogenic cycles, a Mid-Precambrian formation, called “Transamazonian” (Proterozoic Era), and an Upper-Precambrian to Cambrian called “Brasiliano” (Proterozoic-Paleozoic). The soil structure of the city of Rio de Janeiro is represented by a core of crystalline rocks, usually granite-gneiss, covered with a layer of residual soil and/or partially weathered rock.JA Station is located in a Rio de Janeiro neighborhood called Ipanema, between the Atlantic Ocean and Lagoon Rodrigo de Freitas. Local geology is composed of a superficial soil, consisting of medium to coarse grained sands. Top of rock varied significantly from 20 m (66 ft) deep on one side of the station to 33 m (108 ft) on the other. Water is at a depth of 3 m (10 ft)."

Jan 1, 2016

By Josef K. Alter

Crosshole Sonic Logging (CSL) of drilled shafts requires 1.5-in (38-mm) or 2-in (51-mm) I.D. sonic access tubes to be installed inside the steel reinforcement cage. The sonic access tubes do not contribute to the structural capacity of the drilled shaft. The proposed use of Ischebeck TITAN T73/56 CSL/Hollow Threaded Rebar for Cross Hole Sonic Logging Access Tubes Combined with Longitudinal Concrete Reinforcing in Drilled Shafts (patent pending) is discussed as an alternative method of construction and CSL probe access. The T73/56 hollow threaded rebar/sonic access tube performs as a high strength rebar while at the same time creating a 2.2-in (56-mm) I.D. sonic access tube. The deformed high strength hollow bar provides better adhesion to concrete thus reducing the problem of debonding associated with smooth PVC and steel pipe. A cost comparison using conventional rebar with added sonic access tubes is discussed. The use of T73/56 CSL/Hollow Threaded Rebar as a value engineering alternative can reduce both material and labor costs for drilled shaft construction and can provide an advantage where anchor bolt cages and longitudinal reinforcing create congestion.

Jan 1, 2011

Jan 1, 1990

By Robert E. Schock, Eric J. Risberg

"Less than 20,000 years ago, the last of the glaciers retreated from the Chicago region. They left behind sheets of glacial clay till underlain by dense, over-consolidated till (“hardpan”) below which is the limestone bedrock, found about 100 ft (30.5 m) below street level. The most notable feature in this profile is the unusually soft clay till that has historically been called “Chicago Blue Clay.”But the founding fathers of Chicago really didn’t care about what was under the ground. They recognized the importance of the city’s location as a potential trade and transportation hub. With access to the East through the Great Lakes and access to the West through the Mississippi River system, the viability of the city was evident. Chicago’s population grew rapidly. The city continued to grow through the Civil War years, but was dealt a devastating blow in 1871 by the Great Chicago Fire, leaving the city in ruins. The Birth of the SkyscraperAfter the cleanup of the Great Fire came the first real building boom in Chicago’s history. During this era, buildings were generally founded on shallow footings bearing on sand or clay. Many multistory buildings were constructed between 1880 and 1890 on spread footings. The first tall buildings were constructed with load bearing masonry walls. These early tall buildings suffered significant settlement as the soft clay underwent consolidation.The Home Insurance Building, built in 1885, was 12-stories tall and is generally acknowledged to be the first “skyscraper” in the U.S. It was the first building constructed with an iron skeleton frame instead of load bearing masonry walls. Spread footings were used under the interior columns in an effort to better distribute the loads, but the building still experienced large settlements.Construction began for the Monadnock Building in 1891. The 17-story building was built using load bearing walls 7 ft (2.1 m) thick, supported on rail-grillage footing foundations. When completed in 1893, the Monadnock Building boasted the title “World’s Largest Office Building.” The total building settlement over the past 125 years has been measured at over 20 in (0.51 m). The engineering community in the late 19th century observed settlement, but did not yet understand the process of consolidation of the soft clay beneath the city. During this time, many of the new buildings required structural repairs during and after construction; the problem was especially acute in buildings where highrise towers joined lower podium structures."

Jan 1, 2016

By Don Deardorff, Ke Yang, Yingcai Han, Ken Sorensen, Robert Kruger, Mark Petersen, Diane Fiorelli, Larry Goldfarb, Kathryn Petek, Kwabena Ofori-Awuah

Design of deep foundations for lateral loads requires an understanding of soil-foundation-structure response during loading. Lateral loads on a deep foundation (piles) could be due to earthquakes, winds, waves, and/or machine vibrations. Over the years, analysis of response of piles due to lateral loads evolved from closed-form solutions to p-y methods to strain wedge to finite element/finite difference modeling. Although analysis of lateral response of piles and shafts is routinely performed, there is no single guidance document and/or standard for design and testing. Several different analytical methods are available for the analysis, and the resulting design can result in significantly different responses which can create confusion. This is especially true for analyzing and designing piles in potentially liquefiable soils with lateral spread issues under seismic conditions.This guidance document is intended to assist geotechnical engineers, pile designers, and contractors in analysis, design, and testing of piles and drilled shafts for lateral loads. This document discusses the background of different analytical and testing procedures and presents the recommended methods for analysis, design and testing of piles for lateral loads.Chapter 1 defines the different kinds of lateral loads to which a single pile or pile group may be subjected. This first chapter also presents different types of piles used to resist lateral loads.Chapter 2 discusses geotechnical issues related to lateral pile design such as liquefaction and lateral spreading and other non-seismic issues. Also addressed in Chapter 2 is geotechnical site characterization (as related to lateral loads) in terms of site investigation, in-situ testing, geophysical testing, laboratory testing, and estimation of soil/rock properties.Chapter 3 discusses the background and available analytical methods and tools for the analysis and design of single piles and drilled shafts. Several methods of analyses from closed-form elastic solutions to the finite element/finite difference solutions and their applicability are discussed. Available commercial computer software packages for analyzing single piles and drilled shafts are also presented.Chapter 4 expands the discussion of single piles and drilled shafts into the analysis and design of pile groups. In addition, group effects, resistance of pile caps, results of previous experimental and analytical studies, and available analysis tools and software for pile groups are discussed.Chapter 5 presents the issue of lateral resistance of piles and drilled shafts as discussed in different national and international building and non-building codes. A summary of extensive research on several codes are presented to facilitate the compliance with different codes.Chapter 6 discusses structural design issues of individual piles and drilled shafts such as depth of fixity.Chapter 7 discusses soil structure interaction issues related to kinematic and inertial effects due to seismic loading and available methods of analyses.Chapter 8 discusses and presents the typical procedures for the lateral load testing of piles. This guideline was developed as an aid to the practicing engineer in providing information, direction and commentary on the lateral design of deep foundations. Although all reasonable effort has been made to accurately compile the material and information contained herein, no warranty is made with regard to any such material or information and the Deep Foundation Institute assumes no responsibility for any possible errors or any direct or indirect result of the use of any such material or information. It is not intended that this document address every factor affecting lateral design for every situation. Therefore it is the responsibility of the person utilizing information from this document to confirm that it is appropriate and correct for their situation as well as to understand and properly apply

Jan 1, 2012

By Hyu-Soung Shin

This study is concerned with the characteristics of the behavior of steel-concrete composite drilled shafts, a material that is used for large bridge foundations, and especially for weak submerged ground conditions. Depending on the loading or boundary conditions considered, the behavior of foundation will vary. The bearing capacity of steel-concrete composite drilled shaft is influenced by initiation and propagation of fractures along the interface between steel casing and filled concrete. The interface effect is taken into account with the following two simplified cases: (1) detached model with free interface (no shear stiffness of interface) between concrete core and steel casing, (2) confined model by an upper steel cap with free interface. In the confined model, it is intended to have an unified behavior of composite shaft between concrete core and steel casing but there is interface between them. Intensive numerical studies have been undertaken to investigate detailed behavior of the composite shaft. In this study, 3-D finite element analysis is employed. Ground conditions typical of those encountered for the design of drilled shaft under water are considered affecting the behavior. Also, an attempt is made to generate possible combinations of the loads which have been considered in fields. Detailed characteristics of the stress and displacement distributions are evaluated to understand the mechanisms of composite shafts.

Jan 1, 2007

By Dan Brown

A method is outlined for computing the contribution of a micropile group to global stability of a sliding mass. The forces in the micropile are computed in a way which accounts for the effect of soil mass movement on the mobilization of axial and shear forces and which maintains compatibility between shear and axial force as a function of displacement. The method provides a rigorous model to incorporate the pile forces into the stability calculations, including the effect of pile forces on the resultant shear and normal forces at the sliding surface. This paper demonstrates the proposed solution using a simple example slope.

Jan 1, 2007