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By Armin W. Stuedlein, Youssef Bougataya

Early stage design of driven piles primarily relies on static analysis based on one or a combination of total and effective stress approaches, the latter known as the method to estimate axial capacity. A database of 85 piles driven in the Puget Sound Lowland region and monitored at End of Driving (EOD) and Beginning of Restrike (BOR) was compiled along with capacities estimated using the CAPWAP procedure. Established soil profiles based on borings with standard penetration tests (SPT), cone penetration tests, and geologic maps were matched with their corresponding unit shaft resistance profiles from the CAPWAP procedure and resulted in more than 1,200 observations. In this study, eight new models were developed to predict the coefficients at EOD and BOR, based on the corresponding USCS categorization. Each coefficient model is formulated using a three-parameter exponential function, calibrated to capture the profile of coefficients with depth. These models could benefit the designer by providing them with a simple, empirical model that accounts for soil type and setup in a smooth, continuous function with depth. A parallel analysis was performed to assess the accuracy and variability of the formulated prediction models to facilitate implementation in load and resistance factor design (LRFD). INTRODUCTION The design of the axial capacity of driven piles during the planning stages of a project is typically based on a static analysis approach. The goals of this approach are to predict the components of capacity, consisting of the shaft and toe bearing resistances, and to assess project concept feasibility and preliminary lengths. In most cases, this analysis is based on empirically-developed methods, such as the total stress method, also known as the method (Tomlinson 1987) or the effective stress method known as the method (Esrig and Kirby 1979; Fellenius 1991). Many other methods, such as those based on in-situ test results exist and rely on correlations of blow counts from the standard penetration test (SPT), and cone tip and sleeve friction resistance from the cone penetration test (CPT), to shaft and toe pile resistances (Schmertmann 1978; Meyerhof 1976; Nottingham and Schmertmann 1975; Nordlund 1963; Eslami and Fellenius, 1997; De Ruiter and Beringen 1979). Although these methods were generally developed using data from specific geological regions, they are often recommended in national design manuals (e.g., FHWA, Hannigan et al. 2006).

Jan 1, 2018

By Darrell Wilder

When designing excavation support systems in urban environments, it is often necessary to consider the effect of vertical surcharge loads from adjacent structures. Several methods are used in practice to establish the horizontal surcharge-induce pressure on the excavation support. According to the experience of the authors, these methods often seem to overestimate the effect of the surcharge and may have significant impact on the construction costs. This paper explores several of these procedures and provides a discussion as to the reasons for the differences in surcharge effect predictions between different procedures. It also provides practical recommendations for designers dealing with excavation support design.

Jan 1, 2006

By Seth L. Pearlman

A major excavation support case history for the Eastern approach to the Third Harbor Tunnel (THT) in Boston, MA is described, which uses an anchored Soil Mixed Wall (SMW). Both general and project specific information is provided regarding the design and construction of SMW walls. In addition, conclusions are presented that discuss the suitability of this particular application and other possible variations.

Jan 1, 1993

By Makoto Kimura

Failure tests on laterally loaded single and pile group are analyzed with a 3-dimensional elasto-plastic finite element program. In the analysis, the mechanical behavior of the ground is supposed to be elasto-perfect plastic with Drucker-Prager's yielding criterion. The nonlinearity of the piles is simulated by assuming a hyperbolic relation between the bending moment and the curvature of the piles. The influence of the axial stress on the cast-in-place concrete piles is also considered in the numerical analysis. It is found that the mechanical behavior of the piles subjected to lateral loading, such as the load-displacement relation up to an ultimately large deformation, and the distribution of bending moment in the pile group can be well simulated.

Jan 1, 1996

By J. Matos e Silva

"Abstract Although one can think that it is very low the probability of a seism occurrence during the execution of an excavation in an urban lot protected by a diaphragm wall curtain, reality shows that whenever a seism occurs in an urban area several diaphragm walls will be affected by it. So it is advisable to consider the seismic action when designing a diaphragm wall curtain. The paper refers the main information about the seismic design of diaphragm walls according to the Eurocodes 7 and 8 and to the Portuguese Norms related to them (respectively NP EN 1997-1 2010 and NP EN 1998-5 2010), as the Eurocodes consider the possibility of each European country to adopt their own seismic parameters as the seismic risk is different in each country. Thus the so-called National Document of Application (in our case the Portuguese Norms) prescribes the seismic local parameters.1 - EUROCODES AND PORTUGUESE NORMS PRESCRIPTIONSAccording to Eurocode 8 - Part 5 and to the related Portuguese Norm NP EN 1998-5 2010, seismic actions on soils should be quantified adopting the Mononobe-Okabe method that gives goodapproaches when compared with reality.From paragraph 7.3.2.2 of the referred Norm, the horizontal seismic coefficient kh will be:"

Jan 1, 2014

By David Siu

Many problems were encountered with the mechanical wedge-type splices used for the 15-inch square precast prestressed concrete piles installed at an industrial plant site. Many of the wedges were breaking during installation of the splices and after pile driving resumed following splicing. Dynamic monitoring of the piles and uplift loading tests confirmed that the problems were associated with cracked or damaged wedges. More ductile, annealed wedges were subsequently used, and, while not completely satisfactory, they were found to perform better than the original more brittle wedges. Introduction Long precast prestressed concrete piles were installed to support heavy, settlement-sensitive structures at an industrial plant in Port Alberni, British Columbia, Canada. The piles were driven through soft compressible silts and clays to toe bearing in a dense sand and gravel deposit or on bedrock. Each pile consisted of two or three segments joined with mechanical wedge-type splices trademarked DYN-A-SPLICE. Shortly after construction began, problems arose during pile installation, and these problems were, later, identified to be related to the wedges, or clamps, used to connect the splice plates.

Jan 1, 1991

By Rozbeh Moghaddam, William D. Lawson, Priyantha W. Jayawickrama, Hoyoung Seo, James G. Surles

"This study provides calibration of resistance factors (?) for design of driven piles to implement Load and Resistance Factor Design (LRFD) for bridge foundations using Texas Cone Penetration (TCP) Test data. The basic research approach was to compile a database of published full-scale load tests including projects from the Texas Department of Transportation’s (TxDOT) historical archive and projects from neighboring state DOTs. Load test results from neighboring states were leveraged by performing new geotechnical borings with TCP tests at the project sites. The final dataset consisted of 30 load tests performed on precast square concrete piles, with pile widths ranging from 356 to 508 mm and penetration depths ranging from 5.2 to 25.5 m, driven in soils. Ultimate capacities for each load test were interpreted based on Davisson, 5%, and 10% settlement criteria. These measured ultimate capacities were compared against predicted capacities estimated from TCP blow count values (NTCP) and design charts following the procedures outlined in TxDOT’s Geotechnical Manual. From the comparisons, statistical parameters of the biases (??= measured capacity/predicted capacity) such as mean and coefficient of variation were obtained. Resistance factors (?) for LRFD were then determined using Monte-Carlo simulations for each ultimate capacity criteria with the target reliability indices of 2.33 and 3.00.INTRODUCTIONThe Texas Department of Transportation (TxDOT) has used the Texas Cone Penetration (TCP) test since its development in the 1940s. The TCP test is an in-situ penetration test to characterize the materials encountered during geotechnical exploration. Texas currently maintains over 53,000 bridges in the National Bridge Inventory (FHWA 2016), and most of these bridges plus other transportation infrastructure in Texas are supported by foundations designed using the TCP test and its associated foundation design method. The Oklahoma DOT adopted the TCP test and foundation design approach in the 1970s, so the foundations for most of the 23,000 bridges in Oklahoma’s inventory were also designed using the TCP method. With this significant body of experience, the TCP method has been viewed as a straightforward, relatively easy-touse foundation design method that consistently yields safe, serviceable, economical, and maintainable foundations. TxDOT’s deep foundation design method is documented in the TxDOT Geotechnical Manual (TxDOT 2012) and currently employs the allowable stress design (ASD) approach. However, the Federal Highway Administration (FHWA) has mandated that the states begin to implement the LRFD method in place of the older ASD approach (Densmore 2000). This paper presents resistance factors at ultimate limit state (ULS) for design of driven piles using the TCP test, resulting from efforts to be in compliance with the FHWA policy."

Jan 1, 2017

By Fabio Santillán, Mario Mauro, Raffaella Granata

"This paper presents the utilization of slurry walls methods for the recent remediation of three high hazard active dams in the United States. Tuttle Creek Dam, located in Manhattan, KS, required seismic retrofit. To this extent, transverse shear walls were installed on the downstream slope using self-hardening slurry (SHS) to reinforce the liquefiable foundation soils. Herbert Hoover Dike, located around Lake Okeechobee, FL, is subject to potential failure because of internal erosion, piping and slope instability at high water levels. The innovative use of the hydromill equipment with SHS allowed the successful construction of the cutoff wall through heterogeneous soils and rock. At Bolivar Dam, located in Bolivar, OH, under-seepage negatively affects the structural stability of the dam, and a partial seepage barrier wall is required through the upstream slope of the dam. In this case, the Contractor selected the plastic concrete seepage barrier, excavated by a combination of clamshell and hydromill equipment. The main features of the three projects are summarized in Table 1. IntroductionTuttle Creek Dam was constructed by the U.S. Army Corp of Engineers (USACE) on the Big Blue River in North-East Kansas in the 1950s for flood control. Tuttle Creek Dam is a zoned earthfill embankment, 7,500 ft long and about 137 ft high with a crest width of 50 ft (Fig. 1). It is located in an area of moderate seismicity associated with an old continental rift zone located just to the east of the dam. The USACE, under the Dam Safety and Assurance Program, determined the need for remediation. Site investigations and geotechnical analyses identified the upper alluvial foundation sands as being susceptible to liquefaction when subjected to the Maximum Credible Earthquake.In 2005, USACE awarded a construction-manager-at-risk/early Contractor involvement contract. The USACE and the Contractor closely cooperated to identify the most effective technologies, materials and configurations to be used in the remediation. The original remediation design required both the upstream and downstream slope stabilization of liquefiable foundation. Results of refined seismic deformation analyses revealed that the stabilization of the downstream slope and toe was needed to protect the downstream seepage control system and to provide assurance that a liquefaction-induced flow slide would not occur (Stark et al., 2012)."

Jan 1, 2016

By Derrick Dasenbrock, Mary C. Nodine, Benjamin Rivers

Up to 50 percent of major infrastructure projects suffer impacts to schedule or cost due to geotechnical issues, many of which correspond to risks related directly or indirectly to the scope and quality of site characterization work. The Federal Highway Administration (FHWA) in coordination with industry organizations seeks to address this issue through Every Day Counts (EDC), a program that identifies and deploys proven, yet underutilized innovations at the project level to save time, money and resources. The A-GaME (Advanced Geotechnical Methods in Exploration) is one of the innovations supported under EDC.

By Harpal Parmar

This paper evaluates dynamic methods of pile capacity prediction by comparing their results to static load test results. Dynamic and static pile load test data were assembled from four southeastern states of the U.S. End-of-drive and restrike capacities were evaluated using the Pile Driving Analyzer (PDA) and by wave equation (WEAP) analyses. These were compared to static (Davisson criterion) loads. The best comparison was obtained for restrike PDA results; restrike wave equation analyses values also compared well. The end-of-drive results for both methods-showed relatively poor comparisons. The PDA was recognized as an important tool to measure energy transferred to the pile; this transferred energy was recognized as an uncertainty when conducting wave equation analyses. A statistical analysis showed restrike capacity results to be associated with higher precision and accuracy as compared to end-of-drive methods. The authors believe that restrike dynamic testing is essential to establish long term static soil strength and that it will lead to accurate and cost-effective design of piles.

Jan 1, 1996

Jan 1, 1998

By G. Price

The Building Research Establishment installed a base load cell in a driven cast-in-place pile prior to it being tested under vertical load. The monitored base loads were found to be significantly less than could have been predicted by current design methods. The less than expected capacity was attributed to the drilling out procedure. An electro-level system installed in a second similarly formed pile, provided detailed information on the performance of the pile under lateral load. The information obtained was used to check several current design methods for laterally loaded piles. The findings show the potential dangers of attempting to improve design parameters from only limited performance data.

Jan 1, 2010

By Madan B. Karkee

The understanding and the development of sound theoretical basis concerning the pile foundations has been phenomenal during the past few decades, considering the thousands of years the piles have evidently been in use. The importance of the quality assurance and the need for verification of load bearing capacity is being further reinforced rather than undermined by these developments. This is evidenced by significant developments made in the pile load test technology in recent decades, making it possible to make judicious selection of a test method, or a package of test methods, suitable for a given situation. The selection depends on the objective of carrying out the test and the reliability desired. Presently, the possible selection ranges from dynamic to static methods. The extent of dynamic effect in a test can be reckoned based on a dimensionless parameter defined as the 'relative duration'. Examples of different load tests are given for illustration of the different methods currently in use.

Jan 1, 1997

By Robert Fernie

Demographics and Infrastructure demands have led to a significant increase in construction of: deep basements for buildings and, trough structures for Highway and Rail/Metro. Concrete embedded walls used for temporary works can be incorporated into permanent works and because of this (and geological conditions) tend to be favoured in UK. This paper considers British practice in the provision of diaphragm (slurry) walls secant (true and pseudo) piled walls contiguous piled walls Plant utilisation, construction techniques, reinforcement placement, connections, propping, water tightness, tolerances, general UK practices and their relation to design practices are discussed. [ ]

Jan 1, 2000

By Eric R. Borys, Amaneh E. Kenarsari, Brett Gitskin

This case study discusses impacts of excessive Earth Retention System (ERS) lateral movement at a project in city of Chicago. The ERS (cantilevered sheeting) moved inward towards the excavation and caused lateral displacement and cracks in six drilled shafts located about 1 to 2 lateral feet (0.3 to 0.6 m) from the face of the sheet pile wall. Up to 9 inches (23 cm) of horizontal movement was observed on top of the supporting sheet-pile. Similarly, survey measurements showed the top of the drilled shafts moved laterally up to 8 inches (20.3 cm). To evaluate the cause of failure and determine a remediation solution, the soil, shaft and site conditions were investigated. Pile Integrity Tests (PIT) were conducted at the affected drilled shafts. The shafts with identified anomalies were cored and video-recorded. The cause of the failure was determined to be related to variable soil conditions across the site, deeper excavation (i.e., increased effective ERS wall height), and other differences between design and as-built conditions. Internal bracing, in the form of walers and rakers, was installed to limit further movement of the sheet pile as a short-term solution, with additional grade beams framed into the basement slab-on-grade as a long- term solution. Five of the six cracked shafts were spliced with reinforcing bars and high strength grout and one shaft was replaced. INTRODUCTION The subsoil in the Chicago Area mostly consists of glacial till clays underlain by water-bearing granular soil over bedrock. The glacial clays have very soft to medium consistencies for a typical thickness of 30 to 50 feet (9.1 to 15.2 m) below which hard clays (Hardpan, i.e., heavily over-consolidated clay soils) are encountered. The soft clays are often referred to as the “Chicago Blue Clay”. Beach Sands are also found above upper soft clays in several areas, especially within a three-mile strip near Lake Michigan (Peck and Reed 1954). Due to the existence of soft clay in Chicago area, supporting the mid to high rise buildings on drilled shafts extended to Hardpan is a common practice in modern building design. In the early 19th century it used to take about 3 weeks to excavate 1 shaft hole and about 1½ days to fill the shaft with concrete in Chicago (Manierre 1916). The early 19th century methodology of excavating a shaft consisted of hand digging the shaft, installing wood lagging as temporary shoring with spoils removed with a rope and pulley system from the surface. Today, the excavation of a typical drilled shaft in Chicago uses heavy drilling equipment and requires much less time for excavation and concrete placement. It is not uncommon for contractors to excavate shafts and place concrete at a rate of about 2 to 5 drilled shafts per day (with one drill rig).

Jan 1, 2018

By Sastry Putcha, Vamshi Vemula, Aneesh Goly, Kumar Allady

Current dynamic testing practice to obtain pile total capacity will not yield optimum capacity due to the strain incompatibility between the side and tip resistances during driving. Superposition of end of initial drive- static tip capacity and the peak static skin capacity during beginning of restrike and adding them is the preferred method. The FDOT method determines independent pile static tip and skin capacities in real time analyzing appropriate blows from the embedded tip and top data of the Embedded Data Collectors (EDC). This data is collected through a wireless radio transmitter, receiver, and laptop software. The approach utilizes EDC tip and top data and nonlinear single degree of freedom system to satisfy force and energy equilibrium with a global genetic inversion analysis. Top impacted energy equals at pile tip as sum of Static, Damping and Inertial energy providing independent tip resistance. With EDC sensors as boundary conditions, pile is divided into desired segments and using global inversion techniques one dimensional equation is solved for independent skin friction for every blow. EDC data compared close static load test results. The EDC - FDOT method has enabled cost effective 100% testing of driven piles cost effective. INTRODUCTION Historical documentation has shown that not only driven piles have a long history of usage but also continues to advance unceasingly till today. Historians placed the first pile driving using timber piles in the 4th century BC. While modern pile driving systematically started around nineteenth century, the credit for conceiving the idea of the applicability of wave equation to driven piles goes to David Victor Isaccs of Australia. His 1931publication “Concrete Pile Driving Formulae” provides the basis for modern pile driving using stress wave theory. He felt that the dynamic formulae then in use lacked the capability of detecting integrity and hence developed stress wave theory. This work was further developed starting in 1938 by W.H. Glanville and colleagues of British Building Research Board as they developed the first solution to the wave equation. But these early efforts have really taken off only with the advent of computers. E.A.L. Smith (1960) published ‘Pile Driving Analysis with the Wave Equation’ and provided first numerical solution to the wave equation. Within few years, the FHWA funded research and in due course this effort ushered the era of externally instrumented pile driving.

Jan 1, 2018

By Arturo Ressi di Cervia

Construction of the drilled shafts for the Brightman Street Bridge Replacement Project were not only challenging due to working over the water but were also challenged by changed soil conditions, concurrent work being performed by an adjacent contractor on the same project, environmental restrictions and severe winter conditions. A total of 36 x 8 feet diameter drilled shafts with 7.5 feet rock sockets were installed for the East and West bascule piers. This project also included Osterberg Cell load testing on two production drilled shafts at each the East and West bascule piers. The results from the load test program were used to fine tune the design of the drilled shaft rock sockets. From a constructability standpoint the reverse circulation drilling method with a pile top drill rig proved to be an excellent choice for drilling the overburden and rock sockets of the large diameter deep drilled shafts.

Jan 1, 2003

By K. Rainer Massarsch

The effects of soil displacement caused by pile driving on adjacent piles and structures are discussed. A method is proposed to estimate the point of force equilibrium which makes it possible to calculate up-lift forces and pile head movements. For the case of pre-coring a method is proposed to estimate the stability of the bore hole, based on cavity expansion theory. Model tests were performed to establish the displacement pattern of the soil during the driving of a pile group. It can be concluded that at the ground surface, already installed piles have little influence on the lateral displacements, but reduce significantly the soil heave. During the driving of a pile group, the soil is displaced according to a complicated pattern, which is strongly influenced by the order in which the piles are driven. In clay the displaced soil volume corresponds to the total volume of driven piles.

Jan 1, 1989

By Pierre Gouvin

"This paper discusses real time monitoring of utility vaults during the reconstruction of the Elliot Bay Seawall in Seattle. The project, undertaken because deterioration of the old wall posed increasing risks to property and lives, impacts businesses, ferry terminals, a rail line, and electrical utilities that distribute power to much of the downtown area. The project, which has been fast tracked to minimize risk and commercial impacts, involves multiple contractors with heavy machinery working in an area one mile long and only a few hundred feet wide. This presented challenges to monitoring of the utilities, as will be discussed in the paper.INTRODUCTIONThe Elliot Bay Seawall (EBSW) was built in over a period of 18 years, starting in 1916. It consisted of a vertical concrete wall placed on a timber pilings and timber relieving platform. The seawall also retained fill that served as the foundation for a road known as the Alaskan Way. The seawall has performed well over the years, but now cracks in the concrete have allowed loss of fill, and the timber piles and support structures have been weakened by marine boring insects.The project to replace the seawall was undertaken because deterioration of the old wall posed increasing risks to property and lives. Because the project impacts businesses, tourism, ferry terminals, and a rail line, it was given a compressed timeline - 36 months from start to finish. In addition, construction activities have been staged carefully to minimize disruption of Salmon and other wildlife living in Puget Sound. In fact, will incorporate several habitat improvements to promote sea life, such as a nature-imitating textures in the surface of the wall and a glass deck structure that allows sunlight to reach the water. (Fig. 1) shows a schematic of the planned new wall.The sheet piling, concrete piles, jet grouting, drilled shafts, ground freezing, and demolition activities are all taking place in the narrow corridor that holds the subsurface ducts and vaults protecting Seattle’s electrical power distribution. If the network of duct bank and vaults were to experience differential settlement during work here, then most of downtown Seattle would be in the dark. Thus it was important to provide real-time displacement monitoring of these utility structures."

Jan 1, 2017

By Lucien P. Weber

Over the last few years, increased customer demands as well as strong competition from substitute materials have accelerated the development of advanced technologies to improve both the performance and the cost-effectiveness of steel H-piles. On the material side, the development of an in-line heat treatment, combined with the most advanced steelmaking and rolling techniques, allowed to create a new generation of high-strength low-alloy steel grades, called HISTAR, achieving yield points up to 500 MPa (~72 ksi) and yet maintaining excellent weldability properties thanks to a low carbon equivalent. The topic of this paper is to illustrate the performance of H-bearing piles in HISTAR steel grades. In 1989, a major test program was started at different locations in Hong Kong, which is renowned for its difficult soil and severe driving conditions. After the successful completion of these tests, the HISTAR bearing piles were accepted by the local building authorities. Thanks to their cost-effectiveness, the HISTAR bearing piles have subsequently been used with great success in areas with appropriate soil conditions, especially in Asia and more recently in Europe.

Jan 1, 1997