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By Patrick J. Hannigan

A comparison of 40 statically and dynamically load tested piles was performed to evaluate the variation between testing methods. This evaluation indicated an agreement of 10% to 15% could be obtained when the available static resistance is fully mobilized by both methods and when time dependent capacity changes are minimized. Dynamic pile testing recommendations for minimum induced impact force, ram weight to pile weight ratio, and considerations for time dependent capacity changes are presented.

Jan 1, 1987

By Alan B. Wagner

Data from seven instrumented pile load tests in Milwaukee, Wisconsin and two other instrumented load tests reported in the literature, one in Evanston, Illinois and one in Houston, Texas were reviewed. The data were for pipe piles having diameters from 9-5/8 inches to 18 inches, driven to depths between 36 and 96 feet. These data were used to develop a relationship between effective vertical stress and unit side friction and unit end bearing. These relationships were based on readily measured soil parameters, undrained shear strength, Cu, and Standard Penetration Test (SPT) values. This Beta (ß) and Nt approach and four other methods were then used to calculate the bearing capacity of the nine cases analyzed. The results from each of the methods are compared with the measured results.

Jan 1, 1991

By Filippo Maria Leoni, Alessandro Bertero, Gianluca Pianezze

"As part of the Southeast Louisiana (SELA) drainage program, designed by the U.S. Army Corps of Engineers (USACE) to reduce flood damages in the City of New Orleans and surrounding parishes through the construction of new pumping stations and better drainage canals, the SELA-22 project entailed the installation of a concrete covered canal along Jefferson Ave. and Prytania Street, in a highly urbanized portion of Uptown New Orleans, LA. The scope of the required soil improvement was to replace the soil between two parallel lines of sheet piles with a soil-cement mass to eliminate underseepage and provide structural support for the concrete culvert. The USACE selected the jet grouting (Jet Grout) technology for the construction of the bottom plug. The bottom plug is between 18 and 21.5 ft thick with a maximum depth of approximately 40 ft, for a total length of approximately one mile. The treated soil comprised soft clays and silts with occasional presence of sands. Project specifications required 100% area coverage, a 28-days unconfined compressive strength of 100 psi and hydraulic conductivity of 1x10-6 cm/s, to be verified by testing specimens from cored samples. The specialty geotechnical contractor proposed to accomplish the task utilizing their proprietary and innovative elliptical bi-fluid Jet Grout technology, and elected to perform a pre-construction bench scale laboratory mixing program to determine the most suitable grout mix features (i.e. binder type and proportions, binder content, etc.) to be applied in the subsequent field test and production stages. This paper will summarize and compare the results obtained from the different pre-construction and construction stages; interpretations of the data will be provided, along with general considerations regarding the effectiveness and significance of bench scale testing for jet grouting applications.INTRODUCTIONIn general, the effectiveness of the construction parameters in any ground improvement work depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product."

Jan 1, 2016

By Jean-Pierre Hamelin

Ground movements induced by underground excavation are always of critical concern, particularly in urban areas. Compensation grouting now appears as a safe means to control these movements. The paper presents new advanced systems developed by the specialist contractor to bring, at all stages of the project, an efficient control of operations and presents a case history taken from the project at Tren Urbano, Rio Piedras Section, constructed beneath an historic commercial section of San Juan de Puerto Rico.

Jan 1, 2000

By Christian Hoyme, Jochen Maurer, Hans Regler

Up to today, it has been very difficult to obtain qualitative and quantitative information about the status and production process of a construction site. It is becoming more and more important to be able to analyze this process so as to notice bottlenecks and interruptions on the site early on. The high costs of each shift in special foundation industry mean that making the wrong decision and/or interruptions can put the financial result at risk. Previously, keeping reliable data meant manual process documentation. This was done either by an additional staff member (incurring high additional costs for training, education, etc.) or by the equipment operators. The latter is critical, because they have to initiate every process step change, leaving no time to log data separately. Studies have shown that there are considerable deviations from the actual process steps. In this paper, a seamless, automated method will be introduced to analyze the construction process. This method recognizes each process step from the equipment data. The main purpose of the data recorded by the piling rig is the need of quality reports and now basis for the presented analysis. Here, a method was successfully transferred from theoretical computer science (compiler construction field) to find application for process recognition. Because the execution of works in special foundation construction can always be defined sequentially and therefore also practiced sequentially, recognition can occur step-by-step. Our method always recognizes the next step, so it does not have to monitor as much data at the same time. Individual trigger points are easier to define. Unlike solutions that are based on a global approach and allocate suitable process steps to data patterns, thereby also creating gaps, the presented method is always seamless. Furthermore, this method can be applied regardless of time or location provided that the necessary machine data is available, which is normally the case with production data logging. This means that construction sites even from the past can also be analyzed and the results used for comparisons. The first results from the analysis of a complete continuous flight augering (CFA piles) installation process of a construction site will be presented.

Sep 8, 2021

By Renzo D. Verastegui, Michael Law, Sitotaw Y. Fantaye, Alfredas Daugiala

"When completed, 520 Park Avenue will amend the Manhattan skyline and be one of the most prestigious high-rise towers in New York City. The 52-story condominium building is located on a 60 ft by 100 ft lot (18.3 m by 30.5 m) on East 60th Street between Park Avenue and Madison Avenue. The geographically complex site is bounded by two fragile five-story masonry buildings on the east and west, a mid-rise building on the north, and a New York City Transit (NYCT) subway tunnel on the south. To add to this complexity, the ambitious development required an excavation between 70 and 80 ft (21.3 and 24.4 m) deep, mostly below groundwater level in highly-permeable rock, to accommodate four levels of cellars. The new building also cantilevers 24 ft (7.3 m) over a five-story historic building on the east. The limited footprint of the building coupled with large compressive and tensile axial loads, considerable base shear and over-turning moments, and the required deep excavation, presented unique foundation challenges. This article describes how the challenges were solved with an innovative combination of permanent secant pile walls and drilled shafts.Site GeologyThe 1865 Viele Map provides the site topographic conditions prior to development in the area, and indicates that the site was at the eastern edge of a historic marshland, which was approximately west of Park Avenue and north of 58th Street. A historic stream, which ran alongside the eastern edge of the site, was part of a larger stream network that traversed the surrounding area. This stream network is also visible in the 1865 Viele map. In addition, the bedrock beneath the site lies in a highly weathered zone due to a couple of ancient faulted zones that transect the site. These indicate that a zone of highly weathered rock is expected."

Jan 1, 2017

By Benjamin Giacometti, Adam Hacker, Enrique Farfan, Tom Pace

The Louisville Metro Levee System reduces flood risk to the City of Louisville, Kentucky. The levee system was constructed by the U.S. Army Corps of Engineers and is now operated and maintained by the local sponsor, the Louisville and Jefferson County Metropolitan Sewer District (MSD). The levee system has a total length of 26.1 miles, consisting of concrete floodwalls and an earthen levee with sixteen flood pump stations for flood protection.   MSD determined the need to upgrade the existing Paddy’s Run Flood Pump Station’s capacity to reduce the risk of interior flooding. Due to the age and complications associated with upgrading the existing pump station, a new flood pump station will be constructed within the existing levee prism and portions of the existing station will be selectively demolished. MSD initiated a Progressive Design-Build project for a new Paddy’s Run Flood Pump Station. The project proposed a diaphragm wall construction to serve as the temporary support of excavation for the new flood pump station, permanent foundation for the new flood pump station, levee under seepage cutoff, and embankment stability. The lateral soil pressures on the diaphragm walls result from the staged construction sequence, including the effects of bracing to provide lateral support to each wall, and soil-structure interaction. To properly account for these effects, Plaxis 2D models were created for different sections of the structures. The lateral soil pressures for the diaphragm wall design were obtained from the output of these Plaxis models. This paper and presentation summarizes the geotechnical aspects of the diaphragm wall design and how it was used to inform the structural design.

Oct 7, 2024

By Jamie D. McEwan

To cater for the future introduction of 12 car trains, London Blackfriars railway station is being extended from the north end to span across the River Thames. Following the demolition of existing buildings, a number of challenges had to be overcome including working adjacent to a live railway line, above live London Underground tracks and working in small restricted spaces. Trains entering and exiting two lines of track at the bridge's north end of track meant that access was difficult due to the location and proximity to existing infrastructure. The site was very much constrained and congested and there were also a series of works in place to maintain passenger flows so as not to inconvenience the travelling public. The site had been developed many times in the past resulting in a number of obstructions that would require removal during the piling work including old brickwork, reinforced concrete, redundant railway sleepers and track and existing concrete and timber piles. A number of solutions had to be devised to overcome these obstructions. Piling works were undertaken during the day and at night to meet programme.

Jan 1, 2011

By Richard Guenther

As available space in urban centers becomes more scarce, builders and developers are increasingly turning to vacant, existing structures to meet cities' growing needs. The developers of City Ridge Roadside Development and North America Sekisui House (NASH) - - found a suitable site for their "urban village" at the former Fannie Mae headquarters complex on Wisconsin Ave. NW in Washington, D.C., which had been vacated in early 2018. The urban village will consist of eight new structures centered around the building that currently sits on the site. All told, the project will include 687 residential units, a 150-room hotel, over 150,000 sq ft (13,935 sq m) of retail space, and 62,000 sq ft (5,760 sq m) of office space. A below-grade parking structure will extend across most of the footprint. The Fannie Mae building, which was designed in the Colonial Revival style to mimic the Governor's Palace in Williamsburg, Virginia, was named a historical landmark following a request from the development team. The central portion of its existing masonry structure was built in 1956 on pile caps with small-diameter cast-in-place piles. Two wings, which were added in 1962, were built on belled caissons. There are three levels above grade and one below.

Feb 1, 2022

By H. S. Radhakrishna

Foundations supporting power transmission and communications towers are subjected to both compression and uplift loads, often of a cyclic nature. Some novel foundations, combining the beneficial features of grouted and helix anchors with that of compression piles and grillages, were developed by Ontario Hydro during the construction of high voltage transmission lines in Ontario, Canada. In addition to meeting the load requirements, the foundations permit easy installation in swampy areas and also minimize impact on environmentally sensitive terrain. This paper describes the features of these composite foundations and outlines the performance criteria used for their design and installation on the basis of load test results.

Jan 1, 2010

By Alan Walka, Paul Deterling

The existing B and D wings of the Somerville High School in Somerville, Massachusetts, were required to be underpinned to allow for additions to and a large expansion of this facility. A combination of micropiles and soil nailing was designed by Earthwork Engineering and Hub to provide both structural underpinning of the existing foundations and lateral support for both the structures and the soils below the foundations. The depth of the exca­vation was up to 25 ft (8 m) below the existing foundations.

Sep 1, 2024

By Alan Walka, Paul Deterling

Nestled among the lovely 19th century Greek revival, Queen Anne and Italianate architecture, Somerville High School sits atop the Spring Hill in Somerville, Massachusetts. Originally constructed in 1872, the high school has experienced several major renovations and This is the first in a additions throughout it 147-year history. Citing inefficient heating and cooling systems, inadequate access, structural repairs to its exterior, and that all major building systems were at the end of their useful life, the Massa­chusetts School Building Authority approved a feas­ibility study for construction and renovation and city residents voted overwhelmingly to fund the estimated $256 million project, making it the most expensive high school construction project in Massa­chusetts' history.

Jul 1, 2024

By Brad W. Taylor

"During the past several months, I have introduced to civil and structural engineers an innovative solution for the integrity testing of concrete using the Thermal Integrity Profiler (TIP) Wire Cable System by Pile Dynamics. While in the process of “educating” highly-trained professionals about a technological breakthrough, I ended up being educated myself about their needs for quality control/quality assurance (QA/QC). With that in mind, I would like to focus on their two key areas of concern:• How complex is the TIP installation process?• How does the QA/QC engineereffectively analyze and report TIP test results?A few months ago, during a discussion with a senior QA engineer, he asked a question that stopped me in my tracks: “Why should we do foundation testing at all?” Turning it around, I asked, “Why wouldn’t QA/QC personnel want to know everything they could about their critical infrastructure foundation?” Honestly, I didn’t answer his question nor did I fully comprehend what he was trying to say. With his experience, the engineer understood that there has not been an integrity test or a combination of integrity tests that could deliver an inside the cage and outside the cage (cover) complete data set that would provide a definitive profile of the entire shaft. Crosshole sonic logging (CSL) becomes more effective the larger the diameter of the shaft becomes, with a maximum effectiveness between 70% and 80%, but does not provide any data of the integrity of the shaft beyond a straight line between CSL tubes. Gamma-gamma logging (GGL) provides qualitative information about the concrete surrounding the GGL tube and device, and it provides information about a small percentage of the drilled shaft concrete near its outside edge."

Jan 1, 2017

By Y. Duraisamy

This paper presents the compressibility of tropical peat reinforced with cylindrical cement column. When a cement column installed vertically in peat, its compressibility was reduced because of the hardened skeleton matrix formed by cement particles bonding with adjacent soil particles in the presence of pore water. The effects of diameter, number of columns and cement proportions in cement columns on the compressibility have been investigated in this study. The results indicated that compressibility index Cc and Ca decreased with the increase in diameter of the cement column. Specimens with 45 mm and 60 mm diameter of cement column were cured for 28 days, after which they were subjected to Rowe Cell Consolidation test. Based on the results obtained, it shows that cement columns can successfully reduce the compressibility of tropical peat.

Jan 1, 2007

By M. Hesham El Naggar, Osama F. E. Drbe

"Abstract: The use of micropiles has greatly increased the last twenty years, including applications involving low capacity micropile networks, seismic retrofitting, underpinning of existing foundations and high capacity foundations for new structures. This paper presents a field study of the behaviour of single hollow core micropiles in firm to stiff lean clay. Eight micropiles were installed using hollow bars (76 mm OD and 48 mm ID) with air/water flushing technique and advanced to a depth of 5.75m: six micropiles were installed using 228 mm (9 in) drill bit and two micropiles were installed using 178 mm (7 in) drill bit. All micropiles were instrumented with linear potentiometers to measure the vertical displacement of the micropile head and vibrating wire strain gauges to measure the axial strain at three points along the micropile length. Twelve full scale tests were conducted on the eight micropiles, four monotonic compression, four cyclic compression and four tension tests. Only the results of micropiles tested under monotonic compression is presented in this paper. The full scale load tests and a comparison of the performance of the micropiles with 228 mm and 178 mm drill bit are presented and discussed in terms of load-displacement curves, bond strength and tip resistance. The results showed that the proposed values of bond strength in FHWA give a conservative design of the hollow core micropiles. The micropiles constructed with 228 mm drill bit performed marginallybetter than the micropile with 178 mm drill bit in terms of the ultimate capacity.IntroductionMicropiles have been defined in a variety of ways, but can universally be classified as small diameter (less than 300mm), bored, and grouted in place piles (FHWA, 2005; Bruce et al., 1999; and Scherer et al., 1996). They can sustain axial (compression and tension) and/or lateral loads. Dr. Fernando Lizzi used micropiles in 1952 for underpinning of historic buildings damaged during World War II (Bruce D. A., 1988). Since then, micropile applications have expanded rapidly to include underpinning for existing foundations, in situ reinforcement, and seismic retrofitting and foundations for new construction. In particular, micropiles have graduated from use in low-capacity micropile networks toapplications as single high-capacity foundation.Micropiles capacity is affected by the construction technique, which involves drilling, placing reinforcement, and placing or pressurizing the grout. For example, the drilling method influences the degree of bonding between the grout and the ground, and the placement of reinforcement and the choice of grouting method have an impact on the development of the bonding. Bruce et al. (1997) showed that grout/ground bond is most affected by the grouting method. Based on the type of pressure applied during the grouting process, micropiles are classified as follows (FHWA, 2005): Type A: grout is placed under gravity pressure only using either sand-cement mortars or neat cement grout. Type B: pressures typically in the range of 0.5 MPa to 1 MPa are applied in order to inject the neat cement grout into the drilled hole while the temporary drill casing is withdrawn. Type C: involves two-step process; neat cement grout is first placed in the hole under gravity pressure head only as in type A, and prior to the hardening of this primary grout, a similar grout is then injected via a preplaced sleeved grout pipe at a pressure of at least 1 MPa. Type D: like type C, this type is a twostep process: neat cement grout is placed in the hole under gravity pressure head only (but pressure could be applied in some cases), additional grout is injected via a sleeved grout pipe at a pressure of 2 MPa to 8 MPa once the primary grout has hardened. In some cases, a packer is used inside the sleeved pipe, enabling specific horizons to be treated. Recently, Type E micropile is proposed, which involves"

Jan 1, 2014

By E. E. De Beer

This paper describes a method for the determination of the settlement of an individual H-bearing pile, based on the results of CPT-tests. As implied by the nature of the problem, no analysis performed on one pile can be regarded as generally valid for a whole piling foundation project because, even on one site, the pile behaviour varies from one pile to another. Consequently, no precise mathematical analysis has been established; the proposed procedure represents a simple model for the determination of the probable settlement behaviour of an H-pile under a compressive load. Prior to the settlement computations, the rupture load and the resistance distribution along the pile have to be determined. Since the method for the determination of the H-pile bearing capacity from the results of CPT tests has been described elsewhere (de Beer, 1971, 72; de Beer et al., 1982; Arbed, 1985), no details will be given in this paper. The proposed method is valid for both uniform and non-uniform H-piles. The computed results have been satisfactorely compared to the static loading tests performed on different types of piles in clayey and sandy soils during an ECSC research program on H-bearing piles (1983-1987).

Jan 1, 1987

By Charles Roeder, Amy Leland, Dawn E. Lehman

Concrete filled steel tubes (CFSTs) are composite members that are commonly used in many countries today. CFST components are used in the United States, but they are more common in Asia, in part because the connections used in Asia are quite labor intensive and there are not standard connections in the U.S. In addition, US design specifications are prepared by separate groups for structural steel and reinforced concrete structures and so composite systems that use CFST components are not overseen by a single group and as such there are several, conflicting design standards. In the US, steel tubes used for CFST are more slender (i.e., the diameter-to-thickness, D/t, ratio is larger) than some other countries, and labor practices (structural steel labor is different than reinforcing steel labor) also cause potential conflicts in construction. As a result, CFST has had some use in tall building construction in the US, but very limited use in bridge construction. A research program at the University of Washington has been in progress to address many of these issues with an eye towards universal design expressions, simpler, standardized connections and promotion of accelerated bridge construction (ABC). The research has resulted in recent changes to the American Association of State Highway Officials (AASHTO) bridge design specification as well as state departments of transportation (DOTs), which supports the increased use of CFST in bridge pile and drilled-shaft foundations. An experimental research study which investigate the flexural strength, shear strength and connections was conducted. These connections provide good performance under both seismic and gravity loads and address the concerns of US construction. These connections, their design rules and requirements, and their impact on composite behavior and system performance are discussed. These results permit rapid and economical construction of CFST bridge piers, piles and drilled shaft foundations. They encourage the use of more slender and economical tubes, while achieving the benefits of composite construction. INTRODUCTION Concrete filled steel tubes (CFSTs) are widely used for bridge and building construction in Asia, but the use of CFST in bridge construction is limited in the US. The historical use of structural steel and reinforced concrete in US bridge construction have resulted in more developed design expression for those construction methods, which has limited the use of CFST. Bridge construction in the US is inherently different than in Asia because of differences in codes, labor costs and construction practices. As a consequence, design and construction practices that are economical and practical in other countries may not be practical for US bridge construction.

Jan 1, 2019

By Nuno Cruz

"The concrete overbreak estimation for bored piles provides the quantification of the shaft’s expansion beyond its theoretical volume. There are stability analysis methods that can be employed before and after concrete pour but as for the moment of decision, during pile cast, the most common method still consists in measuring the rising of the concrete level in order to compare its poured volume with the theoretical pile section volume. This is a determinant parameter to monitor, not only because it assesses the bored shaft stability but also because it represents a direct cost. When analyzing the estimation methods commonly applied on-site it becomes evident that these are often affected by human errors that lead to misleading results. The objective of this paper is to identify those errors and discuss a subject which is usually overlooked. As a general conclusion, it was ascertained that most errors derive from inaccurate volumetric data, working procedures and gauging equipment. By acknowledging these widespread practices deep foundations contractors will be in a better position to make informed decisions on how to correct and improve bored pile stability.GENERALBackgroundWhen executing bored piles, the estimation of its concrete overbreak allows a swift appraisal of the excavation stability during the drilling process. This is simply obtained from the proportion of the poured volume of concrete over the drilled shaft theoretical volume, as shown in equation [1].Where CO = concrete overbreak percentage, Vc = volume of poured concrete, Vr = pile’s theoretical volume. This calculation not only provides a general idea of the shaft’s expansion from its theoretical volume, but also the outline of the excavated column’s geometry. For the latter, the outline will be as accurate as the number of measurements taken for each partial known volume of poured concrete. This means that for each load placed inside the excavation there is a corresponding rising of the concrete level. The profile of the definite pile is then plotted (see Fig. 1) and allows inferring about how stable remained the shaft walls up to the moment of casting.The technological developments in this area have provided other methods for determining pile stability before and after pile cast, such as ultrasonic echo sensing, cross-hole sonic logging or thermal integrity profiling systems. Notwithstanding, concrete overbreak assessment remains as common practice and confers the advantage of providing stability information during the process of pile casting."

Jan 1, 2017

By L. D. Johnson

12 groups of 12 precast prestressed (PCPS) piles were driven in the lagoon of Kwajalein Island to support a dry dock. Pre-construction investigation of the calcareous coral sands and static pile loeid tests were performed to determine if the 7.9 by 7.9 cm (20 by 20 inches) by 26 m (85 ft) long PCPS piles embedded to a depth of 16 m (53 ft) would adequately support the dry dock. Driving records for production piles indicated that the blowcounts of the piles at the fincil embedment depth became substantially less than expected as piles wssre driven further toward the lagoon end of the dry dock and decreased to as low as 2 blows/ft. A supplemental investigation that included a static load test on a production pile, the driving of an indicator pile, and restrikes indicated that the pile foundation has adequate bearing capacity. The observed bearing capacity appears to be effected by several mechanisms including breakdown of cementation between sand particles, densification of the sands during driving, and dissipation of excess pore pressures and recementation after driving.

Jan 1, 1993

By Rob van Dorp

Most traditional foundation designs are based on soil investigations using Standard Penetration Testing (SPT), sometimes combined with static load testing on sacrificial trial piles. However, this design approach has two major shortcomings. First, SPT data do not provide direct and continuous informa- tion about soil resistance as a function of depth. Second and more important, because of the relatively wide spacing between borehole locations, SPT soil investigations do not provide adequate information about variability of soil profile and/or soil resistance over the project area. Preliminary pile load testing on an SPT location can compen- sate for the first disadvantage but cannot address the second disadvantage. A design approach based on an adequate soil investigation campaign with Cone

May 1, 2022