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By W. Tom Witherspoon

Many Engineers are skeptical and cautious about skin friction factors for the portion of drilled piers where temporary casing is used. This has led Texas engineers in many cases to eliminate skin friction values for the cased section, which necessitates deepening the drilled shaft to compensate for the loss in the cased section. This paper has provided field test data that supports inclusion of skin friction in the temporarily cased hole section as a contributing factor in total axial capacity as comparable to open hole shafts of the same diameter. Reasons for the resultant friction values are provided including; remolding of the cased clay section and the increased pier circumference necessitated by the oversized casing required for adherence to the engineers shaft diameter specification.

Jan 1, 2009

By Sun Jiale

This paper presents a brief description of information construction technology for supported excavation to assure satisfactory performance of engineered system. As a successful example of application of the technique, quite a few troublesome problems, such as high groundwater level in soft ground and crowded buildings around the excavation, were solved satisfactorily in the construction of the new tower of Guangzhou Overseas Chinese Manison.

Jan 1, 1991

By Jon H. Gould

This paper describes the following at the new Advanced Solid Rocket Motor (ASRM) nozzle manufacturing facility, which is being constructed inside an existing manufacturing facility: 1) generalized subsurface conditions, 2) pile load test program and evaluation, 3) pile selection, 4) problems associated with pile driving operations, and 5) production pile installation. The poor subsurface conditions, known and unknown underground obstructions, and work environment inside the existing building, used to manufacture the Space Shuttle external fuel tanks, required special pile installation equipment, procedures, and work schedules to install the economical pile foundation system ahead of schedule and without a lost time accident. GEOTECHNICAL STUDIES In April and May 1990, 16 soil test borings were drilled inside the existing building with a truck-mounted drill rig. The borings extended to depths ranging from 60 to 65 ft (18.3 to 19.8 m) below the floor slab. Typically, the silty and clayey soils were sampled by pushing "undisturbed" Shelby tubes, and the more sandy soils were sampled by driving a Standard Penetration Test (SPT) split-spoon sampler. The unconfined compressive strength, water content, and unit weight of the Shelby tube samples were measured in the laboratory. A geotechnical report was issued in May 1990 presenting the results of the field and laboratory testing and foundation recommendations (Gilbert, 1990).

Jan 1, 1992

By Geoffrey C. Hebner

Augered, cast-in-place piles (ACIP) have become a very common foundation type in Atlanta and the Southern Piedmont Province as well as much of the United States in the past 20 years. Prior to the introduction of ACIP foundations in Atlanta, the most common deep foundation type was Raymond piles. Raymond piles are basically a driven, thin-walled step-tapered steel pile filled with concrete. Drilled piers were also relatively common and continue to be used, particularly in shallow bedrock or high column load situations. Driven piles, including pipes, H-sections, and timber piles were previously common with working loads typically in the 30 to 50-ton range. Initially, ACIP foundations had similar allowable capacities, however, over time improvements in installation techniques and equipment have resulted in an increase in allowable ACIP capacities. Correspondingly, they have become a more cost-effective and trusted foundation for geotechnical and structural engineers. Over the next several decades many other deep foundation alternatives began to lose popularity. ACIP are one of the predominant deep foundations in Atlanta and the Southern Piedmont today. Although ACIP foundations have widespread popularity in the private sector, they have not been readily accepted currently by government transportation agencies. ACIP may be used by some of the smaller municipalities, but to the author's knowledge, have not been used with regularity by larger, state agencies.

Jan 1, 2003

By Federico Pagliacci, Claudio Asioli, Marco Chiarabelli

"""Rigid inclusions"" are a consolidation method that provides improvement of soft soils thanks to the installation of cylindrical columns made up of a material with significant and permanent cohesive properties, whose stiffness is 500÷5000 times greater than the surrounding natural soil’s. ""Rigid inclusions"" find their application in marginal areas (reclamations, polluted sites) to ensure stability of adjacent structures during construction of new buildings and to reduce the impact of natural disasters (liquefaction in the event of earthquakes, embankment collapse in the event of floods). This paper analyses the “rigid inclusion” construction method, related materials and equipment. Moreover, two performed projects will be illustrated. The first is the restoration of Lungarno Torrigiani Embankment in Florence, Italy. In May 2016, the Torrigiani embankment underwent a structural collapse causing a 3 m. displacement of the riverbank towards the Arno River. “Rigid inclusions” (with 300 mm diameter) have been used to re-compact the loose soil and create a stable working platform for the equipment. The second project illustrates the use of “rigid inclusions” (800 mm diameter and maximum depth of 36.6 m) to control the settlement of a new automatic cold store (30 m high with a 65 x 120 m foot print) for fresh frozen vegetables.RIGID INCLUSIONSIn general, the word ""inclusions"" means a type of consolidation that improves the strength of a soil mass through the inclusion of elements constituted by a material having better characteristics than those of the surrounding natural ground, to improve the overall mechanical characteristics of the treated soil. Inclusions are ""rigid"" when the material introduced into the ground has significant and permanent cohesive properties (concrete or cement mortar) and a significantly higher stiffness (500 ÷ 5000 times) than that of the surrounding natural ground.Typically, medium-small diameters (from 300 to 800mm) with low percentages of treatment (from 2% to 10% of the volume of soil) are employed, ensuring a high quality and consistency of the obtained product, both in terms of diameters and elastic modulus.According to the scope of the project and in urban areas, ""rigid inclusion"" columns can also be performed by means of small diameter drilling rigs (micropiles), weighing less than 20-25 tonnes."

Jan 1, 2017

By Rudolph P. Frizzi

"Abstract Pile design for building structures in the United States is typically performed by: 1) investigating and assigning engineering parameters to the respective ground bearing materials, 2) calculating ultimate pile to ground (geotechnical) capacity which is then reduced by a Safety Factor deemed appropriate by a registered Design Professional thereby arriving at an allowable pile geotechnical pile capacity, and 3) determining the required pile structural section using allowable pile section material properties. It is advantageous to use a Working Stress Design Method (WSDM) approach as one system of loads (service loads) are used in both the geotechnical and structural evaluation. There are a variety of methods used to determine the ultimate and allowable geotechnical capacity, and Building Codes often require a registered Design Professional to determine the appropriate method(s) and capacities. The International Building Code is the Code typically referenced in building design and construction in the United States. Structural design usually follows Building Code requirements and Allowable Stress Design (ASD) procedures. As design of the overlying structure typically follows a Strength Design Method (SDM) approach using factored loads, in some cases piling is first designed for pile-to-soil interaction using service loads, followed by evaluating the pile geometry for factored loads. Construction is the finalization and implementation of the designed piling. As such, project-specific technical specifications are typically developed by a registered Design Professional such that a project Owner can bid, buy, and instruct a Contractor as to the desired piling work and acceptance criteria. There are several Industry groups, including DFI, PDCA, ADSC, and ACI that provide guidance documents which the registered Design Professional can refer to in developing the piling technical specifications. It is the author’s opinion that the registered Design Professional is best suited to observe and verify the piling installation; many Building Departments require verification and documentation by a registered Professional as a condition of final acceptance.INTRODUCTIONPile design for building structures consists of: investigation, design, specification, and verification. In major metropolitan areas within the United States, Building Codes typically identify minimum requirements for each of the above steps. The International Building Code (ICC, 2012) is the Code typically referenced in building design and construction in the United States. Recognizing the ground conditions as well as piling construction means and methods can vary on a site-by-site basis, latitude is given to the registered Design Professional and Contractor to optimize the piling system for the respective project conditions. Field testing and quality control / assurance measures are typically implemented to verify the design intent is attained for the production pile elements."

Jan 1, 2014

By Andrew Malinak, William Perkins

Seattle’s Elliott Bay Seawall protects the 1½ miles of downtown waterfront between South Washington and Broad streets. The seawall supports the urban waterfront and infrastructure, including the Alaskan Way Viaduct and Alaskan Way, access to historic waterfront piers, and numerous essential buried utilities. Most of the original seawall was constructed between 1916 and 1936 over soft/loose non-engineered fill, estuary, and beach deposits. The majority of the original seawall was a pile-supported timber relieving platform that extended up to 60 feet behind the face of the wall (Figure 1). With maximum spacing between the timber piles of 3 to 5 feet, a virtual forest of timber piles were driven for the original wall.

Jan 1, 2018

By Leena Korkiala-Tanttu, Noora Lindroos, Juha Forsman

"Construction works at the Helsinki city sea shoreline requires dredging and handling of contaminated sediments. Most of these soft dredged sediments are regarded as too poor quality material for earth construction purposes. Mass stabilization technology has been applied to improve the technical and environmental properties of the dredged sediment in order to utilize the material in construction. The treatment site presented in this article is placed in the West Harbor where the dredged sediments are disposed in basins, mixed with binders by mass stabilization and transported to utilization sites. The volume of these basins is about 90 000 m3. So far these basins have been used three times during the years 2011-2014. The most applied binder has been cement. Its high price and carbon footprint have encouraged use alternative binders. Other used binder materials include fly ash and end product of desulphurization from coal combustion, and fly ash from combustion of Estonian oil shale. The technical and environmental properties of stabilized sediments have been studies in the laboratory and in situ thoroughly. Some properties of the stabilized sediments which have been studied are: compression strength, modulus, hydraulic conductivity, leaching of contaminants, etc. The leaching test results show that heavy metal leaching is very low with all binder materials tested.1. INTRODUCTIONContaminated marine sedimentsMarine sediments in the coastal areas are often contaminated as a consequence of industrial and port activities, as well as the influence of cities located there. Construction activities and reclamation of shore line require dredging and handling of contaminated sediments since the level of contamination inhibit dumping of dredged sediments into the sea. Based on their technical properties, most of these dredged soft and watery sediments (clay, gyttja, etc.) are regarded as too poor quality material for earth construction purposes. Economic, sustainable and environmentally safe management of contaminated, dredged sediments is a key issue in many construction sites.In the City of Helsinki, mass stabilization technology has been applied to improve the technical properties of the dredged sediments in order to utilize the material in construction. Owing to stabilization / deep mixing / solidification, also the contamination is encapsulated in a monolithic solid of a high structural integrity. Thus, contaminants migration is restricted by the decreased surface area exposed to leaching.The treatment site presented in this article is placed in the West Harbor (a place of Helsinki called Jätkäsaari) where dredged sediments are disposed into stabilization basins, mixed with binders by mass stabilization and then transported to final utilization sites. The location and principle of these basins is presented in Figures 1-4. The overall volume of these four stabilization basins is about 90 000 m3."

Jan 1, 2015

By Paul J. Axtell

Self-hardening cement-bentontie (c-b) slurry walls were constructed as shear walls to stabilize the downstream slope of Tuttle Creek Dam near Manhattan, Kansas. The slope stabilization was required to protect the existing pressure relief well system located at the downstream toe of the dam. The wells require protection from slope deformation induced by liquefaction of the foundation sands during or immediately after the design seismic event. The shear walls are transverse to the axis of the dam, unreinforced, and relatively brittle members that may be exposed to relatively large shear strains, and possible cracking, during or immediately after shaking. An extensive laboratory investigation was conducted on recovered core samples to optimize the mix design and stabilization scheme. Furthermore, as is the topic of this paper, a portion of the laboratory investigation was to determine the large-strain, or post-peak, shear strength of the c-b material for use in limit-equilibrium slope stability analyses and numerical deformation modeling to assess the magnitude of permanent deformation caused by the design earthquake. These data may be beneficial to other projects that are considering the use of unreinforced c-b slurry walls for seismic retrofit purposes.

Jan 1, 2010

By Eiji Kojima

In this research, dynamic and static load tests were performed on permanent foundation piles which had a pile length of 30 m, 800 mm in outer diameter and 15 mm in wall thickness. In this site the dynamic horizontal load test on a smaller test pile, 12 m in length, 500 mm in outer diameter and 12 mm in wall thickness, was also carried out. The static horizontal load versus horizontal displacement derived from the dynamic load test conformed well to that measured in the conventional static horizontal load test of the pile with 800 mm diameter. Then an attempt was made to predict the horizontal load displacement of the pile with 800 mm diameter based on the results of the dynamic horizontal load test of the pile with smaller diameter of 500 mm.

Jan 1, 2006

By R. Bruce Patterson

The New Tacoma Narrows Bridge is a classic suspension bridge founded on concrete caissons. Caisson construction was complicated by the proximity of the existing bridge piers, only sixty feet away. High capacity plate anchors were used successfully to moor the new caissons in currents as strong as seven knots during construction.

Jan 1, 2004

By D. Michael Holloway

The California Department of Transportation (CALTRANS) evaluated several pile foundation schemes for supporting the structures along the realignment of Interstate 880. The project replaces the double-decked (Cypress) viaduct collapsed in Oakland, California during the 1989 Loma Prieta Earthquake. Structural support demands led to the selection of steel pipe piles (16-, 24-, and 42-inch-(406-, 610- and 1067-mm-)diameter), filled with concrete and steel reinforcement. Deep penetrations required through layers of very dense/cemented sands in some locations, caused serious drivability and pile integrity concerns. The need for large pile driving hammers and large diameter steel pipe piles pushed the engineers well beyond local experience. Such questions as the feasibility of driving the pipes closed-ended through dense upper strata and quantifying the effects of installation on the long-term capacities of the piles led Caltrans to develop a comprehensive pile test program to address the design and construction issues effectively. The results were furnished to prospective bidders on the production stages of the ensuing contracts.

Jan 1, 1995

By Jeff Jackson, Paul Axtell, David Graham

The Montana Department of Transportation recently awarded a contract to construct a replacement bridge across the Clark Fork River in Heron, MT. Both abutments and both intermediate bridge bents were to be founded on 6-ft and 8-ft diameter, permanently cased drilled shafts with rock sockets, respectively. Two drilled shafts per substructure location were designed for a total of eight drilled shafts. The original design included 6-ft diameter drilled shafts at the abutments but the Contractor elected to submit a Value Engineering proposal that increased them to 8-ft diameter. On the basis of the subsurface exploration program, extremely challenging subsurface conditions were known to exist, including the potential presence of large boulders within the predominantly sand and gravel soil matrix. The successful bidder elected to use an oscillator to install the permanent casing to the top of bedrock, while simultaneously removing the spoils from inside the casing with a clam-grab. On seven of the eight shafts, this approach worked well. Unfortunately, on one of the shafts, the casing met refusal on one or more boulders encountered in the predominantly sand and gravel soil overburden. Following several attempts, and despite several variations of approaches, it was determined that the casing could not be advanced beyond the obstruction without unacceptable risks to the pile-supported temporary work trestle (i.e., loss of soil and reduction in pile capacity for the foundations supporting the work trestle). To mitigate the problematic drilled shaft, a unique solution was designed and successfully constructed. The solution involved the construction of seven 16-in diameter micropiles constructed within the confines of the obstructed casing. The micropiles were drilled to bedrock through the sand, gravel, and boulders and include rock sockets to satisfy axial design requirements. The micropile casing thickness, grade and grout strength were designed to provide adequate flexural strength as well as to satisfy other design requirements. Upon completion of the micropile installation, the upper portion of the drilled shaft above the boulders and within the permanent casing was constructed as usual. This paper discusses the difficult subsurface conditions at the site, the drilled shaft construction difficulties, and the design and construction of the micropile solution.

Jan 1, 2018

By Stefan K. Schwank

The paper describes the two foundation techniques - mini piles and postgrouted bored piles. The mini pile system is presented with its design and installation parameters, especially the drilling technique. Two case histories demonstrate the application under extremely limited space and traffic conditions and the required modifications of the equipment. After the description of the postgrouted bored piles and its grouting technique, the paper gives a comparison of postgrouted piles and standard piles on a large basic test in Germany. The Brooklyn Queen's Expressway, N.Y., case history shows the application of this technique after redesign of the original proposal. 1. General Increasing requirements to improve existing foundations to carry additional loads and to increase the bearing capacity of bored piles leads to two new piling techniques: the mini-pile and the post grouted bored pile.

Jan 1, 1991

By Pete Howell, Patrick Granitzki, Alicia Plinio, Janitha Batagoda

The New York City Housing Authority (NYCHA) Red Hook Houses was subjected to damage during Superstorm Sandy. As a result, the NYCHA has an ongoing project known as Restoration Associated with Sandy Recovery Program to improve the resistance against future storms. The specific project included 28 residential buildings and several service buildings within the Red Hook Development. The subsurface conditions within the eastern portion of the site included existing fill material underlain by varying stratums of very loose, loose and medium dense silty sands followed by very soft to medium stiff clay or dense silty sands. The western portion of the site included existing fill material, very loose to medium dense silty sands and organic clayey silts underlain by very soft to medium stiff sandy silts. Based on the geotechnical report, a conventional driven steel pile system was specified containing two pile depths. As part of the project bidding, an alternative pile type was recommended and analyzed to provide quicker installation, reduce vibrations, reduce noise, and provide relatively large cost savings. Due to relatively high lateral loading, an innovative double steel casing drilled displacement piles was proposed as the alternative pile option. Field testing proved the piles capable of the required project capacities and the use of drilled displacement piles as the best alternative for the project and accepted by the NYCHA.

Oct 1, 2022

By Ali Ameli

Design loads are limited for piles relying upon toe stresses in rock due to uncertainty about the rock quality over the whole pile diameter because of rock mass properties or construction effects. The paper discusses the use of video images to evaluate rock quality at the bottom of piles socketed into graniodorite bedrock in a steel pipe pile project. Skillful interpretation was required to assess the 3D properties of the rock from video images. It is necessary to observe the rock mass characteristics near the project site for better perception of the rock features from the images. Video image interpretation skills were established by the evaluation of the cores drilled under the socket base and the results of pile loading tests. Correlations were found between rock appearance in the images and the rock socket drilling records. Rock socket acceptance criteria were developed through monitoring the drilling operations for the specific site procedures. Video images then served as one of the quality-assurance tools together with probing and pile loading test. Lessons and methods learned from video inspection in this project could be used to evaluate rock quality in similar cases.

Jan 1, 2006

By Sunil S. Basarkar, Dilip M. Dewaikar, Rajesh H. Gajjar

"A load transfer program AXPILE was developed for simulation of the loadmovement characteristics of socketed piles of the Mumbai reg ion. This program used empirical relationships for ultimate shaft resistance at pile-rock interface recommended by Zhang and Einstein (1998). According to their recommendation, ultimate shaft resistance at pile-rock interface is related to the square-root of uniaxial compressive strength of intact socket material by a parameter C, which ranges from 0.4 for smooth sockets to 0.8 for rough sockets. Results of three instrumented pile load tests were compared with the AXPILE generated results. The comparison of analytical and field estimates of the unit shaft resistance confirm the recommendations of Zhang and Einstein (1998) on the unit side shear parameter c,, which was found to be in the range of 0.35 to 0.67.INTRODUCTIONInstrumented pile load tests were carried out on the test piles at the Bandra-Worli sea link project in Mumbai city of western India. High capacity socketed piles were required to take up loads from the superstructure. Hence, in addition to the available toe resistance, an accurate measurement of the shaft resistance in socket portion was desired. The instrumented load tests incorporated Osterbergcell (0-cell) assisted by strain gauge instrumentation to estimate the shaft resistance mobilization in the socket portion.AXPILE load transfer program was developed for load-movement simulation of socketed piles (Basarkar, 2004). The load transfer algorithm based on Coyle and Reese (1966) was incorporated in this program, which used empirical correlations and functions to account for load transfer in piles through shaft and toe resistance.This paper compares the computed unit shaft resistance from the AXPILE program with the measured values recorded from the instrumented pile load test."

Jan 1, 2005

By W. Sondermann

"AbstractWith the increasing demand in reuse of inner city areas and the urgent need for deeper foundation pits under cramped circumstances, adjacent structures close to and high ground water level, the well-known established technologies especially with small to mid-sized dimensions are often too time consuming and occasionally not economic to install lateral support systems. The alternatives for these specific cases could be the usage of the deep mixing technology to create lateral support systems in reinforcing the deep mixing elements additionally to transfer the horizontal loads from earth – and water-pressure.With increasing demand in depth and water tightness, verticality and overlapping of single column solutions are becoming the key in execution. In addition, for some applications subsoil-conditions were not ideal for wet deep mixing technologies. The tubular soil mixing system (TSM) as a combination of mechanical mixing and support of hydraulic cutting by jet grouting can provide solutions toovercome these challenges.1. Current market conditions and trendsThe present financial crisis and the efforts not only to consolidate national budgets, but also to rescue certain banks, have not left the building industry unaffected either. Some drastic cutbacks to public budgets, along with the increasingly restrictive granting of credit for the financing of construction projects, have led to enormous over-capacities in the building sector, with purely negative impact. As a consequence of these negative developments, many companies are experiencing the pressure to restructure more quickly and to reduce costs but at the same time to keep the consequences of all activities, both externally and internally, within limits acceptable to employees, owners and finance institutions and last but not least consumers."

Jan 1, 2014

By Richard Pizzi

Built in 1806, Boston's African Meeting House is the oldest surviving Black church building in the country. A $7 million dollar renovation was begun in 2006 to restore this historic building to its 1855 appearance and to modernize the building's accessibility, electrical and mechanical systems. As part of the restoration, an underground utility room and elevator tower, needed to provide handicap access to the Meeting House, were constructed. Extending up to 17 feet below the foundations of the abutting buildings, the utility room was constructed within one foot of some of Boston's oldest and most expensive residences. All equipment and materials had to enter the work area through a narrow alley rendering conventional methods of excavation and construction of earth support using heavy equipment unfeasible. A unique combination of micropiles, structural cap beam, internal struts and shotcrete facing was designed and constructed to provide the permanent and temporary support of the lateral loads from the earth pressures and adjacent building surcharges and the vertical loads from the elevator tower. The narrow and congested streets of the Beacon Hill neighborhood presented many day-to-day challenges for the contractor.

Jan 1, 2011

By Jean Balech

This paper presents some results of dynamic loading tests performed on concrete piles driven in soft clay formation. The load transfer mechanism, measured in the dynamic increasing energy test (DIET), under blows of growing energy, is described in terms of mobilized normal forces diagrams and unitary local friction and displacements. It was observed that the lateral skin friction grows up to a maximum, in the soft clay layer and, gradually diminishes to a residual value when the system presents the maximum mobilized resistance. It may be concluded that the rupture load is not equal to the maximum mobilized point resistance plus the maximum mobilized local friction as suggested by most of static bearing capacity formulae.

Jan 1, 2002