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By A. K. Bhattacharya

Cylindrical bridge piers are widely used and equations exist that can predict the maximum depth of local scour around such piers. Scour around piers is an undesirable phenomenon, as it requires the foundation to be placed to a greater depth resulting in increased cost, making it worthwhile to investigate scour-reducing measures. A number of scour-reducing measures have been tried out for cylindrical bridge piers including placing a concrete collar around the pier, having a delta-wing projecting upstream in front of the pier, placing riprap around the pier, using a group of piers instead of a single pier, having a slot in the pier aligned in the longitudinal direction. The objective of this study is to investigate the effect of upstream protective piles on reduction of maximum local scour depth around a cylindrical bridge pier. The upstream piles are placed at different radial distances in front of the pier and the scour depths are observed. The proposed equation of Dey (1997) for determining the maximum depth of scour around a cylindrical bridge pier is used. The reduction of local scour around the pier is compared with local scour around an unprotected pier.

Jan 1, 2009

By Mary Ellen Bruce Large, Antonio Marinucci, Silas C. Nichols

Tip post-grouting of bored pile (drilled shaft) foundations refers to a method where cementitious grout is injected beneath the tip of a shaft to improve the overall performance of the constructed foundation. This technique, when performed satisfactorily and in the appropriate ground conditions, enhances axial load-displacement performance by improving the mobilization of pile’s resistance. Potential benefits associated with tip post-grouting include reduced settlement under loading, better alignment of load transfer curves, and improved ground beneath the base of the bored pile. However, to be able to realize the benefits attributed to this method, the design, construction, of both the bored pile and the post-grouting system must meet a minimum level for quality assurance. The various factors affecting the successful installation and performance of a bored pile (e.g., workmanship, base cleanliness, borehole integrity, and concrete placement) have been discussed by numerous practitioners and researchers in the available technical literature. For a conventional (i.e., ungrouted) bored pile, acceptance is based on a combination of visual inspection, material testing, and the results of integrity and/or performance testing of the constructed pile. A properly executed tip post-grouting program can be a relatively comprehensive and complex process, which is typically evaluated throughout the construction process based on the results of prior projects and/or on test pile(s) at the particular site. For tip post- grouting programs, verification procedures and acceptance criteria should be established during and incorporated into the design process to ensure design intent and objectives are achieved. Project specifications should be produced to ensure performance requirements are achieved. This paper will present and discuss factors affecting the successful execution of tip post-grouting, including grouting criteria, instrumentation, reliability and uncertainty with the method and outcome, and verification and acceptance. INTRODUCTION Constructing bored piles (drilled shafts) is increasingly more challenging given the lack of ideal site locations, tight project site confines, difficult or restricted access, greater demands on drilling equipment, and close proximity to adjacent structures. To evaluate the feasibility of bored piles as an appropriate foundation system, a myriad of factors is evaluated during design, including site conditions and constraints, budgeting and scheduling, reliability and risk exposure, presence of and depth to adequate load bearing soils/rock, and the magnitude of the imposed loading. Moreover, updated design codes increased load demand per element, and improved material strengths have led to more complex foundation designs, larger foundation elements, and significant increases in load magnitude. Monopile (monoshaft) foundations have been utilized where one large bored pile is used in lieu of a group of piles connected via a pile cap. In addition, to accommodate the design criteria, site conditions, and imposed loading, the geometry of the bored piles being designed and installed have been as large as 13 feet (4 m) or greater in diameter and to depths in excess of 260 feet (80 m).

Jan 1, 2018

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 J. Osterberg

A new device has been developed for load testing driven piles and drilled shafts which consists of an hydraulic jack or bellows which has a telltale rod fastended to the bottom. The rod extends upward to the surface through a pressure pipe. When pressure is applied, the jack or bellows expands, applying an equal upward and downward load at the bottom. The downward movement at the bottom is indicated by the rod and the upward movement is indicated by the movement at the top. Thus, upward and downward load-deflection curves can be drawn. As load increases, failure will occur either in end bearing or friction. Results of field installations are described. Total loads of up to 1,100 tons metric have been used. The method obviates the need for the reaction load required for the conventional pile loading test and separates friction and end bearing. It is especially advantageous for use over water, in crowded spaces and for inclined piles.

Jan 1, 1989

By Eric M. Klein

As part of the Woodrow Wilson Replacement Bridge project several damaged wetland and environmental areas were to be mitigated. One of the mitigation projects consisted of constructing a Denil fish ladder around Peirce Mill Dam in Rock Creek National Park, Washington, D.C. The dam is a historic structure operated by the National Park Service. The fish ladder is located between the east abutment of the dam and Beach Drive, a major collector road. Construction of the fish ladder required removal of a portion of the east abutment and an excavation that extended about 22-ft below the pavement of Beach Ave. It was not possible to close Beach Drive except for very brief intervals or at night; therefore, a support of excavation system that would minimize disruption to the public was required. The high groundwater required that the groundwater be cut off prior to excavation; the random rubble and soil fill, and shallow but erratic rock surface precluded driving sheet piling. A jet grout system was selected because the grout probe could penetrate the rubble fill, stabilize a variety of soil conditions, and cut off the ground water prior to excavation. It was not possible to construct a stable wall without tiebacks or soil nails. Given the schedule and tight working conditions it was decided that soil nails through the jet grout wall facing would be the most cost effective method, as it did not reduce the working space as rakers would and would be more cost effective than prestressed tiebacks.

Jan 1, 2006

By Matthew Janes

Statnamic load testing is becoming widely accepted as a method to quickly and economically determine the load-deflection behaviour and ultimate static resistance of high capacity deep foundations. Strain instrumented large diameter bored shafts were tested at four locations for the federal and state Departments of Transportation in the United States. Tests were conducted vertically (to 30 MN) and laterally on the shafts and, in some cases, testing was completed over water. Instrumented shaft test results provided shaft load distribution with depth and shaft shear transfer stress throughout the soil stratum. Shaft end bearing and ultimate end bearing stress values were provided. On two projects, Osterberg load cells provided comparative static data for skin friction and end bearing. Correlations between Statnamic derived static load-displacement results and Osterberg load-deflection results are very good. Statnamic lateral load test results were correlated with static lateral results in addition to providing useful dynamic response and damping data.

Jan 1, 1996

By Özgür Bezgin

This paper presents observations on the installation of drilled shafts from two construction projects and an academic study with experimental and analytical parts. The construction projects involved the use of pressurized drilling methods. The experimental part of the academic study involved the use of the auger drilling method. The analytical part of the academic study investigated the effect of drilling methods on the soil-structure interaction and the behavior of drilled shafts under lateral loads. The concept of ?free-length? is introduced for the lateral load design of pressure-drilled shafts that are thought to be fully embedded within a soil media. The academic part of the study presented herein was conducted in Rutgers, the State University of New Jersey.

Jan 1, 2009

By Wolfgang G. Brunner

The closing of the gap in the European waterway- net is one of the big and challenging traffic projects following the German reunification. The water canals in the North German plain connect the Rhine river, the border between Germany and France, with the Oder, the German border river to Poland. As early as in the 30's of the 19th century the planning and construction of a ship- lift and a canal bridge started, in order to close this last big gap in the system between the Mittelland Canal and the Elbe- Havel Canal near Magdeburg. This main waterway connects the West of Germany, known for its coal mines and steel mills, with the capital Berlin, and from there it goes on into Poland. The building activities started in 1934 but came to a complete stop in 1942 because of the war. The communist government in East Germany was not interested in continuing this huge project, including the ship lock Rothensee, the canal bridge crossing the river Elbe, the former border river between West and East Germany, and the lock Hohenwarthe due to lack of political backing along with low construction capacity.

Jan 1, 2000

By Peter Florian

At 5:50 am on October 1, 1992, the new $800 million Pittsburgh International Airport Midfield Terminal opened its gates to the world after five years of construction and more than 24 years of planning. Despite numerous design changes, this massive project was completed on time and substantially within budget. The importance of this airport to Allegheny County and the Pittsburgh region was recognized 24 years earlier by Allegheny County Commissioners Tom Foerster and the late Leonard Staisey. Staisey and Foerster established a program to acquire land for the "Airport of the Future".

Jan 1, 1993

By Rudolph P. Frizzi

Quality control is essential for augered cast-in-place (ACIP) piles (also known as continuous flight auger (CFA) piles outside the United States) and drilled displacement (DD) piles since the pile is constructed below the ground surface out of the direct sight of the personnel constructing and inspecting the pile. ACIP piles are being successfully constructed to support high-rise structures, hospitals, arenas and stadiums, mass transit systems, and power and industrial facilities. The use of DD pile technology is also gaining ground in the United States, typically utilizing proprietary systems such as Omega (currently utilized by Richard Goettle Inc., and LG Barcus and Sons, Inc.), Berkel, and DeWal (currently utilized by Morris-Shea). Different types of ACIP/DD pile installation equipment are shown in Figures 1 and 2. ACIP piles are installed into granular and cohesive soils, and soft rock to lengths currently approaching 130 ft (39.5 m), with diameters up to 24 to 36 inches (610 to 915 mm), and sustaining design loads approaching 900 kips (4000 kN). Current DD pile installation equipment in the United States is capable of installing up to 79-ft-long (24 m) piles with diameters ranging from 12 to 18 inches (305 mm to 460 mm).

Jan 1, 2004

By Willie M. NeSmith

Conventional augered, cast-in-place (ACIP) piles were introduced into the New York City area as a result of the damage to existing structures caused by pile driving operations. ACIP piles are often specified where deep foundations are to be installed adjacent to transit facilities, sensitive underground utilities or in close proximity to existing structures. However, loss-of-ground issues associated with the installation of ACIP piles have prevented the wide-scale use of these systems. Beginning in 2002, Berkel & Company Contractors, Inc. began using its augered, cast-in-place displacement (ACIPD) system in the New York City area. Like conventional ACIP piles, this system produces almost no vibration. Also, as almost no material is brought to the surface, there is no opportunity for loss of ground. This paper presents a description of Berkel's displacement pile system and a brief discussion of six projects in the New York City area that have been executed with this system over the past two years.

Jan 1, 2004

By Jose L. Garcia

The following document aims to cover all issues concerning the three main methods employed for the in-situ survey of concrete pile integrity. Within it are described both sonic coring and low-strain tests and the frequency and time domain analysis of their results, which are the most advanced techniques currently in use in Spain. The survey techniques described were developed and began worldwide deployment in the 1960s, but it was not until the 1980s that they saw large scale implementation in Spain, largely thanks to the miniaturisation of electronics and computer equipment that made them easier to use on-site. Sonic coring, echo and frequency-response testing or mechanical impedance tests are spreading further every day. However, there appears to be a need for standardisation of the testing methods, as well as their implementation, interpretation and the presentation of results. The goal of these Spanish recommendations is to serve as a guideline for test standards and to provide examples for a correct and commonly agreed interpretation of test results, as well as settling any differences in the evaluation of defects detected in foundation works.

Jan 1, 2006

By C. Dai, S Raathiv

The Waikato Expressway is one of the New Zealand Transport Agency’s (NZTA) seven roads of National Significance. Coffey is part of the City Edge Alliance engaged by NZTA for the Hamilton Section of the project. The 22km Hamilton Section is the largest and most geotechnically complex section of the Expressway. The Mangaonua gully in Sector 6 is the most challenging geotechnical area of the project for piling works. Together Coffey and Brian Perry Civil have carried out the temporary and permanent design and construction of embankments, piling works, retaining walls and soil improvement works for the bridge construction. The design and construction works were governed by weak alluvial layers and artesian pressure layers several meters beneath the ground level. This paper presents the action taken to improve the foundation of temporary platform, control the artesian pressure, prevent bentonite leakages into the highly permeable alluvial layer and challenges in the base grouting process. This paper summarises the key components in the construction and supervision of bored piling works and outlines innovative solutions for challenges which we faced during the construction.

Nov 1, 2022

By Roy H. Borde

The design of foundations to support overhead signs is primarily based on providing adequate resistance against horizontal wind loads. The typically used subgrade reaction model for the load-deflection analysis of laterally loaded piles and shafts has been found to underpredict the capacity of shafts with length to diameter ratios less than five. The general applicability of an improved model incorporating the influence of shear and moment resistance at the shaft base is demonstrated. The detrimental effect of ground surface slope angle on the ultimate capacity is discussed, and a design chart for estimating the magnitude of the reduction in capacity is presented. A comparison between the predicted and measured responses of nine full-scale load tests performed within this study and sixteen external tests is presented. The models described are implemented in the computer program "LTBASE".

Jan 1, 1988

By Michael W. Driller, Wen Yan (Grace) Chen, Steven J. Friesen

"Remediation for Perris Dam has been proposed in response to deficiencies identified in a seismic stability study prepared by the California Department of Water Resources (DWR) in 2005. Lenses of potentially liquefiable soil have been identified within the dam foundation which may lose strength during a seismic event. The remediation was designed primarily to limit deformation of the dam. Nineteen construction methods were compared and evaluated for the remediation. The final decision was to use cement deep soil mixing (CDSM) to strengthen the foundation and to construct a downstream berm to stabilize the dam. The entire CDSM treatment will cover over 4,000 linear feet of the downstream toe of the dam. Over 300,000 cubic yards of CDSM will be used to strengthen the foundation. The construction of the project started in Fall 2014 and is anticipated to take approximately 3 years. This paper describes the design aspects of using CDSM to treat the foundation, including laboratory testing, investigation of overstressing/cracking, extent of treatment, effect of CDSM on pore pressures under the dam, and the results of a full-scale CDSM test section.INTRODUCTIONPerris Dam is a zoned earthfill dam with a length of 2.2 miles, a maximum height of 128 feet, and a capacity of 131,450 acre-ft of water. The dam is located in Riverside County, California at the terminus of the East Branch of the State Water Project. The embankment was constructed between 1971 and 1973 over an alluvial deposit between the Bernasconi Hills to the South and Russell Mountains to the North. A rock outcrop divides the dam into left and right reaches when viewed from the reservoir looking downstream. The embankment soil was obtained from a borrow source at the North end of the reservoir. The dam has a sloping sandy clay core (Zone 1) with a 10-foot deep cutoff trench and a silty sand shell (Zone 2) with a downstream chimney and blanket drain (Zone 3 and Zone 4) as shown in Figure 1."

Jan 1, 2015

By Robb L. Swenson

Construction of foundations for the Skyway Segment of the San Francisco Oakland Bay Bridge required innovative techniques due to the mass of the structures being inserted and the unique subsurface of the Bay. Twenty of the pier structures required large sheet pile cofferdams. Eight other foundations were installed in open water without cofferdams at the deeper part of the Bay. This narrative will present the initial planning, as well as the stages of installation, for each type of foundation. The first section will discuss foundation constructability modifications made during the initial planning phases of the project. Considerable effort was expended by Caltrans, the owner, T.Y. Lin the designer, and KFM (Kiewit/FCI/Manson) the contractor in modifying the design to assure that required tolerance would be maintained during the installation of the foundations. The final section will describe the steps required for installation including: initial access dredging, installation of cofferdams, preparation required to install the footing boxes, footing box installation, foundation support pile installation, and pile to box connections.

Jan 1, 2013

By Tatsunori Matsumoto

In order to investigate the variation of the load-displacement relations of piles in a site, vertical load tests were carried out on 25 small diameter steel pipe piles. Out of 25 piles, 15 piles were close-ended pipe piles attached with a blade at the pile toe and 10 piles were open-ended pipe piles. To carry out these load tests in a short period, two types of rapid load test methods, Spring hammer load test and Falling mass load test, were employed. The load tests of all piles were completed in two days with 180 blows in total. In order to estimate a static load-displacement of a pile, non-linear damping method was used. It is shown from the test results that the performance of the pipe piles such as the ultimate pile resistance and the initial pile head stiffness is improved by re-driving.

Jan 1, 2006

By Abid Adekunte

"Engineers and developers have witnessed the growing popularity of deep basement structures as components of urban commercial and residential developments. This is often attributed to inadequate surface parking facilities in urban centres and a somewhat popular belief that underground parking facilities improve both commercial and aesthetic values of urban structures. For many years, diaphragm walls and sheet pile walls have been widely accepted as effective deep excavation support systems for basement construction in urbanised zones. However, these are now being replaced by bored pile retaining walls as preferred earth retention systems of choice on many projects for several reasons, which may include economy, faster installation process, reduced space requirement for machinery and ancillary equipment, flexural rigidity and axial capacities.However, there are complexities associated with the use of bored pile retaining walls on urban developments. These include; limitations due to vertical and horizontal installation tolerances, which is a major issue when wall is required to provide groundwater cut-off for multi-level basements as tolerances are difficult to achieve for deep piles, uncertainty associated with the prediction of wall axial capacity as piles are rarely tested, difficulties in using temporary props as wall restraint due to restricted working spaces in urbanised zones and difficulties in adopting ground anchors as restraint due to the existence of adjacent sensitive structures in built-up areas. Such complexities have resulted in cases of failure, non-serviceability and abandonment of basement construction schemes. Therefore, overcoming the intricacies associated with the application of bored pile walls is becoming a priority to the present day basement engineer.This paper is centred on the numerical modelling, design, construction and monitoring aspects of four recent case histories of multi-level basement and marine engineering construction schemes in the United Kingdom and the Republic of Ireland, which involved the use of bored pile retaining walls. The paper highlights the various customised approaches and innovative novel solutions adopted on the sites, to mitigate risks and ultimately overcome the intricacies associated with the earth retention techniques. Simple empirical equations for developing the geometry of secant pile walls for effective groundwater cut-off are presented and validated. An alternative approach for predicting axial capacities of bored pile walls is also presented; this is shown to be considerably less conservative than a common routine design approach, while also in good agreement with observations made in a recent series of laboratory-based scale model tests."

Jan 1, 2017

By Sunil Arora, Lisheng Shao, Chris Conkle

"The East Garden Grove - Wintersburg Channel located in Orange County, California, required upgrades along the levees to mitigate potential liquefaction and lateral spreading hazards. The Orange County Public Works designed soilcrete columns constructed between two rows of steel sheet piles along both sides of the channel between Graham Street and Warner Avenue (approximately 2,500 ft), and along an approximately 2,000-ft-long stretch of the south levee. The earthen embankment, approximately 13- to 15-ft high and damaged significantly by erosion, was then excavated to widen the channel to increase the channel flood conveyance capacity.The site is located within the Los Angeles Basin, underlain by several thousand ft of marine sedimentary strata. Uncontrolled fill materials were encountered to approximately 10 ft below ground surface, underlain by tidal and flood plain deposits. Groundwater was encountered at sea level, which is approximately 10 ft below grade.This paper will discuss site soil conditions, and the construction and quality control of soilcrete columns constructed by wet soil mixing; also, the paper will introduce the Drilling Index (DI) as a measurement tool, similar to the cone penetration test (CPT), to evaluate the soil strength in more detail. Finally, the statistical analysis of soil mixing strength distributions for the project quality control will be presented.INTRODUCTIONWintersburg Channel in Orange County, California, required ground improvements along the existing levees to mitigate potential liquefaction and lateral spreading under the site design earthquake. Orange County Public Works designed and developed a cellular pattern of soilcrete columns sandwiched between two rows of steel sheet piles along both sides of the channel between Graham Street and Warner Avenue, and adjacent an approximately 2,000-ft-long stretch of the south levee (Fig. 1). An earthen embankment approximately 13 to 15 ft high, damaged significantly by erosion, was then excavated to widen the channel and increase the channel flood conveyance capacity.Stiff, soilcrete cellular wall structures can reduce the earthquake-induced cyclic shear stress ratio (CSR) in the soil within the cells, thus preventing excess pore water pressure build up which may trigger soil liquefaction. For this project, approximately 6,700 soilcrete columns were constructed in a cellular pattern to an approximate depth of 40 ft. All of the soilcrete columns are 3 ft in diameter with the design unconfined compressive strength (UCS) of 150 psi."

Jan 1, 2015

By Mohammed Sakr

A Two-Section Helical Pile (TSHP) is a steel pipe with two shaft sections of different diameters and with one or more helix plates near the bottom of each shaft section. TSHPs are used regularly in western Canada as foundation pockets for single and double circuit distribution power line poles. The results of a comprehensive lateral pile load test program and the field monitoring of TSHPs installed in organic soil (muskeg) over soft clay are presented in this paper. A total of nine full scale lateral load tests were carried out, including seven tests using TSHPs with different diameters and embedment depths, and two tests using one-section helical piles. The prime objective of the study was to evaluate the lateral resistance of TSHPs installed into very soft organic soil (muskeg) overlying soft clay soils, to compare their lateral resistance relative to one-section helical piles and to compare the measured and the estimated lateral resistances using p-y curves. In order to provide sufficient soil data for analysis, the subsurface soil stratification was evaluated using two different techniques including; Cone Penetration Tests (CPT) and Portable Soil Probe Tests (PSPT). The two testing techniques were also compared and evaluated. This paper summarizes subsurface soil conditions, pile configuration, helical pile installation procedure, testing setup and results.

Jan 1, 2009