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By Allan Sylvester

Construction of the Shot Tower Metro Station in Baltimore, Maryland was performed in two phases. In the first phase, a contractor was retained to excavate the station in order to construct twin tunnels from the Shot Tower Station to the John Hopkins Station. The retention system for this 70' deep excavation consisted of a Soldier Pile in Tremie Concrete (SPTC) wall supported by cross-lot bracing. In phase two, The Clark Construction Group, Inc. was retained to construct the station interior structure, two entrances, two station ancillary shaft structures and the track work for the station and tunnel. The excavation for the construction of the two entrances adjacent to the 70' deep station SPTC wall had to proceed prior to completion of the station structure due to the tight construction schedule. A system of overlapping secant piles was specified as a vertical support of excavation element for the West Entrance. The secant piles would have provided a watertight, rigid support to resist the load from the SPTC wall constructed in phase one. A watertight system was required in order to minimize the settlement of adjacent buildings supported on wood piles. Clark Construction was concerned with the constructability, cost and performance of the specified secant piles and looked for other innovative methods of providing a watertight and rigid system. Substitution of a reinforced slurry wall in lieu of the secant piles was cost prohibitive due to the additional cost of concrete placed under tremie. Clark, being familiar with cement-bentonite cut-off walls and slurry wall construction procedures, proposed the construction of a PSHG wall, in lieu of the secant piles. The PSHG wall construction consisted of trenching 30" wide by 20' long by 60' deep panels under a self-hardening slurry. Once the excavation for a panel was completed, a 60' deep prefabricated soldier beam and lagging panel was placed in the slurry. The slurry design mix then self-hardened within the cure time, allowing excavation for the structure to proceed This paper will discuss the design, details and construction methods used on the PSHG wall and will compare the advantages of the PSHG system to conventional support systems.

Jan 1, 1997

By Robert Bittner

The following is a report on the development of two unique and separate cofferdam systems used in the construction of the marine foundations for the I-205 Columbia River Bridge at Portland, Oregon for the Oregon Department of Transportation. The first of these two systems utilized interlocking H-pile 100 ft long to form a cofferdam 145 ft by 58 ft in plan and 100 ft deep. The second system consisted of two immense bell shaped steel forms. The larger of the two forms was 83 ft by 66 ft in plan, 62 ft high and weighed 450 tons. This form was externally stiffened for a designed hydrostatic head of 54 ft. Both forms were designed, except for the top 14 ft, to be set and stripped in one solidly welded unit. The supporting geological formation for the bridge foundations is the Troutdale, a cemented sand and gravel. This formation is at the ground surface on the Washington Shore and slopes downward to a depth of 115 ft below normal high water at about mid-channel. In this area the Troutdale formation is covered with a layer of fine to medium sand 90 to 100 ft thick. It was the variable depth of the Troutdale which determined the two types of foundations and the corresponding to the two cofferdam systems.

Jan 1, 2013

By E. R. Wang

This paper outlines the engineering properties of shallow soil in Shanghai area. The main points that should be paid attention to during deep foundation investigation, and general conditions of experimental soil engineering are discribed.

Jan 1, 2010

By Vahid Tajdar

The behavior similarity between pile and cone penetration test, has guided the researchers to use the CPT results in prediction of piles bearing capacity. In this article, artificial neural networks have been used to study about relation between cone tip and sleeve friction strength obtained from cone penetration test and ultimate pile bearing capacity, obtained from static pile load test. Artificial neural networks "ANNS" is a form of artificial intelligence. ANN tries to dramatize the human nerves & brain system biology structure in self-structure. In this article, the results of relevant studies about the prediction of ultimate pile bearing capacity in especial area of soils are presented by use of back - propagation neural networks. The results of static pile load test up to failure on 63 piles with closed end and CPT test results in the place of construction these piles use in order to confirm and creation ANN model. Comparing predicted ultimate pile bearing capacity by utilizing ANN with the numbers which are predicted by 5 common traditional methods shows that using of artificial neural networks is a suitable method for predicted ultimate pile bearing capacity in identified area of texture of soil moreover it has a better operation in comparison with common traditional methods.

Jan 1, 2006

By Charles Pol Vuillier

Piling work for modification to the Charles Grimes Bridge in Melbourne, Australia required piles to be installed through 15 to 20 m thickness of very soft to soft silty clay overlying 10 m of stiff clays and sands in turn overlying siltstone. The presence of an old sewer founded at depth in the soft clays demanded that vibrations be kept to a minimum. Two pile type were used by Vibro-pile (Australia) to provide the client with the most economical piling price. The two pile types were CFA piles of 750mm diameter founded in the weathered rock and a full displacement concrete injected screw pile developed by Vibro-pile called the "Z" pile, founded on the rock. The development and features of the "Z" pile are briefly discussed, including the perceived applications and advantages of the pile type. On board instrumentation comprising a computer was used to monitor all aspects of the construction. The rig instrumentation provided an important quality control measure that gave confidence in the pile installed. Pile performance was proved on the cast in situ piles by dynamic load testing methods. Initially tests performed with a 120 kN drop hammer, which was not capable of mobilising the required loads. The performance was then satisfactorily proved by using a drop hammer of 20 tonne mass delivering blows drop heights of 1.5m. Low strain integrity tests on a number of piles were also used to confirm the structural integrity of the piles.

Jan 1, 2000

Jan 1, 1988

By Peter Faust, Jeremy Zorne, Timothy Siegel, Diane Fiorelli

Professional sport venue construction follows a very simple rule. Once the decision has been made to move the team to a new place, construction shall begin immediately, so that not more than one or two seasons pass by stuck in the old home. Such tight construction schedules require a different approach than traditional design-bid-build contracts. Design is mostly done on the fly, the construction schedule becomes a main risk factor and an early contractor involvement is desired. As specialty contractors become more and more sophisticated, owners, their construction managers or the general contractor have realized the value of ideas and modern technology they can bring to the table for a successful and fast project completion. Local knowledge and experience in a variety of solutions play a key role in the specialty contractor’s ability to provide added value to the project. This is also true for the specialty foundation contractor, who needs to understand the complexity of such modern structures from its integrate foundation, over the delicate concrete structure to a potentially fancy movable stadium roof. Not to mention all the modern high tech equipment which shall make such a place a great customer experience. His expertise shall enable him to propose the most suitable foundation element for the given ground condition and application. Rather to build what others have designed, his strength is to propose alternate concepts which will be faster and (hopefully) more cost effective. This paper highlights different value engineering (VE) input a specialty foundation contractor had on 3 major sports arena projects in California. Together with the entire team from owner to GC, including the Geotechnical (GEOR) and the Structural Engineer of Record (SEOR), the most efficient and best performing foundation solution can be found every time. But such an approach also requires the open mind of the owner to entertain last minute changes when the permit drawing set has already been submitted for approval.

Jan 1, 2018

By Nicolas Denies, Gust Van Lysebetten, Bart Lameire, Jan Maertens, André Vervoort, Noël Huybrechts, Flor De Cock

"Abstract Originally developed for ground improvement works, the deep mixing method (DMM) has increasingly been applied in recent years for the realization of soil and water retaining structures and as alternative to traditional foundation solutions. From practice, there is a real need for practical guidelines dealing with the execution, the design and the control of such applications. With the aim of developing such guidelines, the BBRI ‘Soil Mix’ project was initiated in 2009. Within this research project, deep soil mix (DSM) material from 38 Belgian construction sites has been tested. In spite of the large advances in the mechanical characterization of the DSM material, one major issue remains the representativeness of the typical core samples in comparison with the real scale behavior of the soil mix elements. There is among others the question of the influence of the unmixed soft soil inclusions on this behavior and the issue of the scale effect which must be considered in the design. In order to investigate these questions, 8 large scale UCS tests and 17 large scale bending tests have been performed on excavated soil mix elements. The present paper discusses results of this experimental campaign, presents some research perspectives and highlights different aspects related to the design of soil mix elements for the realization of retaining wall or foundation solution.INTRODUCTIONSince several decennia, the deep mixing method (DMM) has been used to improve the strength and deformation characteristics of weak soils. In recent years, deep mixing has increasingly been applied – in Belgium and in other countries – for the realization of soil and water retaining structures and alternative foundation concepts. With regard to the execution of the DMM, one can refer to the European standard EN 14679 on deep mixing (2005) that was elaborated under the umbrella of CEN TC 288 “Execution of special geotechnical works”. However, from practice, it has been experienced that this execution standard does not provide enough pragmatic information and guidelines, in particular for the more recent applications of the deep mixing method (with retaining and bearing functions). The same need by the sector for guidance rules linked to design aspects in the context of Eurocode 7 was experienced as well. With the aim of developing such guidelines and in order to provide feedback to the European standardization platforms, the Belgian Building Research Institute (BBRI) has initiated the BBRI ‘Soil Mix’ project (2009-2013) in collaboration with the KU Leuven and the Belgian Association of Foundation Contractors (ABEF), the Belgian branch of the EFFC. Within this research project, deep soil mix (DSM) material from 38 Belgian construction sites, with various soil conditions and for different execution processes (CVR C-mix®, TSM and CSM), has been tested (Denies et al., 2012)."

Jan 1, 2014

By Steven M. Henderson, Zachary D. Jones

The risk of allocation in construction contracts is a primary concern for all parties. For contracts involving subsurface construction the allocation of site condition risk is critical. In the past one hundred years technological advances fundamentally changed how that risk is allocated; yet another shift in this risk allocation may lie just over the horizon due to advances in geotechnical data management. Around the world initiatives are underway to make geotechnical datasets more open and accessible. In the United States some states like Kentucky have already made geotechnical data readily accessible. This proliferation of geotechnical data in the U.S. may impact the allocation of subsurface risk in construction contracts. Many construction contracts contain a differing site condition clause. That clause allows for a modification of the contract price or schedule if the ground conditions encountered by the contractor differ materially from either what was indicated in the contract documents or would be reasonably expected. A contractor, however, is typically not entitled to that modification if the contractor knew or should have known of the adverse conditions encountered. Courts have interpreted the “should have known” language as requiring contractors to make a reasonable site investigation prior to bidding the project. If geotechnical data is available and accessible and reveals the adverse condition the contractor encounters, courts could find that the contractor should have known of the condition and thus will not be entitled to a modification based on the differing site condition clause. Accordingly, the U.S. could be on the threshold of significant shifts in how the risk of differing site conditions is allocated in construction contracts.

Jan 1, 2017

By G. Tamaro

The World Financial Center is situated on a 60,000 square meter site at Battery Park City at the southern tip of Manhattan Island. The foundations for the buildings and the related infrastructure posed difficult design and construction problems since the site was filled land in the Hudson (North) River. Foundation construction was made difficult by both the geology and the existence of two railroad tunnels which passed under the site. The soils at the site were unsuitable to support construction of heavy structures, and as a result, all of the foundations had to be carried down to bedrock, or the glacial till over rock. Two buildings were supported on piling and special battered caissons which provided lateral support against wind loading. The other two buildings were supported directly on rock, requiring excavation to depths of 19 meters (63 feet) below grade.

Jan 1, 1989

By Louis Donolo

New buildings in today's urban environment, especially in down-town areas, invariably involve the construction of multiple level basements. Used for parking, storage and commercial space, these underground structures normally extend 30 to 50' and more below grade and, to make optimum use of expensive land, they usually occupy the full site right up to street/sidewalk and property lines. SOIL SUPPORT SOLUTIONS Building these basements requires vertical excavation, and consequently, a temporary soil support system which will eventually be replaced by the permanent foundation walls of the structure.

Jan 1, 1987

By Z. Q. Zhou

It is the first worke in design of pile foundation to determine the carring capacity of single pile, and a static loading on site is considered to be the lost derect and reliable way. All values P and settlements S induced can be plotted as a broken-line. Since soil is a kind of elasto-plastic and cohesive material, the increasing of settlements is generally greater than that of loads. Different value Pu nay be given by different tester on his P-S diagram, because of erroys in the test and complicated, characteristics of soil. The analytical method of exponential equation shown in this paper derives a specified solution. After using an exponential curve to regress values of loads P and corresponding settlements S from on-site test, coeficients A and B of exponential equation can be obtained. With this curve an ultimate carrying capacity of single pile can be determined. The resistant forces of pile shaft and pile tip can also be defined by the tangent of the calculated knee point, as it is called (tangent method). At last, an example is given to show how the ultimate carrying capacity of f 500mm bored pile is obtained with this method for a project in Kunming.

Jan 1, 2010

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 Tim Chapman

This general report considers what promoters of deep basement projects want from their teams and whether they get it often enough. Most large projects are based on complex financial models where the funding is related to a future income stream. Project delays and cost over-runs can critically affect the financial model. Too often, delays and cost over-runs originate in the substructure and foundations. We must take positive steps to improve our industry's reputation for reliability.

Jan 1, 2006

By P. Ventura

Reliability of the liquefaction analysis is based on data plotted as by piezocone, as by deep vibrocompactation monitored tests. The negative porewater pressure, re lated to hydrostatic value, recorded by piezocone, is a good marker of the absen ce of the liquefaction. Systematic measures of the ground settlements, inside the vibroinfixed steel pipe, allow to locate the liquefable strata with loose density. Experimental study of the combined soil improvement by stone columns is carry out in particular in sea bed. The interaxis of the columns for the best efficiency is valued as of the vibrocompactation, as of the drainage effects, especially during earthquake.

Jan 1, 1989

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 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

By David C. Lager

While not a new construction technique "top/down" construction is seeing increased use in high rise building construction. Using diaphragm wall, drilled shaft and mining construction techniques, top/down construction enables construction of both the below grade basements and high rise structure simultaneously. To date the top/down method has been used on at least four major building projects in the United States. This paper will review the economic, engineering, construction and schedule issues associated with top/down technology on two projects -Olympia Centre, Chicago, and One Westwood, Los Angeles. Top/Down construction is currently under consideration on several additional projects in the United States.

Jan 1, 1987

By Jorj O. Osterberg

The Osterberg (O-Cell) Method makes it possible to separate the side shear resistance (skin friction) from end bearing. The O-Cell is placed on or near the bottom of a drilled shaft and after the concrete is poured and cured, an equal upward and downward pressure is applied. From the test, the load-upward deflection curve in side shear and the load-downward deflection curve in end bearing are drawn. Typical curves are shown where the ultimate load in side-shear is reached and where the ultimate load in end bearing is reached. Several examples of tests in which the test load reached ultimate loads far in excess of what was expected are shown. The side shear in rock sockets is shown to be much larger than generally estimated. Examples are given of where side shear is smaller than expected and the reasons discussed. Disturbance of the sides of drilled holes due to poor construction techniques and ways to avoid these conditions are considered. Examples of bottom hole disturbance are given and ways to prevent the disturbance are discussed. A graph showing the actual measured capacity of drilled shafts compared to the estimated capacity as a function of the hardness and strength of the soil or rock is presented.

Jan 1, 1999

By Alan G. MacKinnon

Loads and stresses from pile driving are increasing from heavier piles and more powerful hammers. Stresses can be dangerous to equipment stability. Equipment developer MacKinnon tells how to compute stresses for all positions of the crane boom and angles of pile batter. From a paper presented at the DFI-University of Hawaii Seminar, April 1985.

Jan 1, 1986