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By Patrick J. Hannigan, Geir Veslegard, Frank Rausche, Rozbeh B. Moghaddam

A common type of deep foundation used in Norway to support bridge structures is the drilled pipe piles (piles) filled with concrete reinforcement after installation. The standard installation practice is the use of down-hole hammers. Complex geology and difficult subsoil conditions in Norway causes a high variability of soil and rock layers which in turn make for differences between actual subsurface conditions and those expected from geotechnical exploratory borings. This situation is strongly noted when the foundations are not fully socketed, and the rock layer is sloped. In this particular case, special testing procedures are required to assess the drilled pile base material and evaluate the rock-socket to ensure full contact between the foundation base and the rock surface. The local standard practice to verify the latter condition, consists of coring and visually evaluating the material recovered at the bottom of the drilled pile. This paper presents a case where the coring and visual inspection were not possible and alternatively the geological material encountered at the base of the deep foundations was evaluated using force-displacement measurements. Two 1016-mm (40in) diameter open-end drilled piles identified as P02-04 and P02-05 were tested and evaluated using in-situ force-displacement data prior to filling the piles with concrete. Test results showed an average displacement of 7mm (0.28in) corresponding to 35MPa (5.1ksi) stress level for P02-04, and 7.2mm (0.28in) corresponding to a stress level of 38MPa (5.5ksi). Based on testing results, both drilled piles were within the established material assessment criterion presented by the local authorities. INTRODUCTION This paper presents a case study in Norway where the material encountered at the base of an open- end drilled pipe pile (pile) was evaluated using force-displacement data. In the deep foundation industry in Norway, it is a common practice to install piles to support transportation structures. Once the piles reach the embedment elevation, and the pile base is assessed, these are filled with concrete. In projects where sloping rock is the supporting layer, and all nominal loads are supported by the pile base resistance, assessing the material encountered at the pile base to ensure full contact with the rock becomes critical. The local practice to make this assessment consists of the use of weighted tape, coring, or inspection cameras. However, similar to any other testing and evaluation methods, these come with their own limitations. The variability associated with the use of the weighted tape, accessibility for the coring equipment to complete a coring process, or the conditions at the foundation base such as murky water or thick drilling fluids could significantly impact the photo or video quality taken at the pile base. In such conditions, it is important to consider alternate testing methods to evaluate the material at the foundation base.

Jan 1, 2018

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 Padmavathi V, M. Najamuddin, M. R. Madhav

Granular piles are one of the leading ground improvement techniques, adopted for the betterment of bearing capacity and reduction in settlements of the foundations and also to accelerate consolidation of the surrounding soil. In the recent past, there has been extensive research on the settlement analysis and behavior of granular piles under varied soil conditions. The application of these theoretical solutions to practical problems requires a knowledge of representative values of the deformation parameters of the ground and the granular piles. However, very little information is available on these parameters. The paper presents a new method for the estimation of the modular ratio of granular piles and modulus of deformation of the surrounding in-situ soil from the compression load tests. The load - settlement response obtained from the compression test results are used in the back analysis for estimating the modulus of deformation of the ground. The presence of granular bed, under the rigid plate for load testing, has been given due consideration in quantifying the proportion of load transferred on to the stone column. Based on these considerations a new method is developed to estimate the modulus of deformation of the ground and the modular ratio of the granular pile.

Sep 1, 2022

By D. Arentsen

Changing environmental laws, new operating requirements and the increasing accuracy with which the bearing capacity of driven piles can be calculated have all led to the development of hydraulic piling hammers, some very primitive, others very advanced. Users find it difficult to decide which model is the most suitable, because the specifications are neither uniform nor unamiguous. There are no standard specifications and, moreover, the majority of hammers are suitable only for a limited range of applications. For the user, however, it is important to choose a hammer which will meet future as well as current requirements and will not quickly become obsolete or be unsuitable for a particular job.

Jan 1, 1987

By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

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 Bruno Gemmi

The objective of the ? 200 million ($280 million) project Parma Railways Station-Urban Transformation was the reconnection of the North and South parts of the town by constructing an 80 m (250 ft) wide sunken artery passing under the four double railway tracks of the station without any impact on train traffic. The site of the project, adjacent to the Parma River, presented water seepage problems at any excavation depth. The use of conventional large diameter bored pile machinery was not allowed by the Railway Authority because equipment dimension and construction phases do not comply with train traffic safety regulations. Foundations for the bypass were thus constructed by minipiles nested into jet-grouted soil using machinery operating within the existing head room and at a safe distance from the tracks. Jet-grouting treatment reached depths of 25 to 28 m (80 to 90 ft) from tracks? grade and embedded minipile-heads were terminated at 2 to 3 m (6.6 to 10 ft) below grade. Load tests on minipiles were pushed to failure. Failure occurred at a 240 t (265 t) load without breakage of the bond between the jet grouted soil and the minipiles. A 0.93 MPa (135 psi) shear resistance ??? between minipile steel casing and the jet grouted soil was measured prior to the failure of the steel casings. Overall measured foundation settlements were well within expected values and were considered insignificant.

Jan 1, 2011

By D. E. Sherwood

Recent developments in high torque hydraulic rotary rigs has lead to the construction of secant bored pile walls by rotary drilling methods in circumstances where earlier methods were difficult and in some cases impossible. The evolution of secant bored pile wall construction is described including classical, rotary drilled and continuous flight auger construction methods. The paper then details the restraints which have been created in recent inner city redevelopment, many of which were not relevant in the early days of the technique. Typical examples of walls are presented to show the adapatability and advantages of the secant bored pile wall method. A number of in-situ retaining wall construction techniques are then compared in detail with regard to relative cost, technical quality and practicality.

Jan 1, 1989

By David G. Winter

The Olive 8 excavation site in Seattle was surrounded on three sides by conditions requiring innovation, careful modeling, and extensive instrumentation to support use of a first-of-its-kind shoring system. The solution combined heavy soldier piles, long and steeply angled tieback anchors, and tightly spaced soil nails to support surcharge loads from a 33-story adjacent tower separated by a narrow alley housing critical utility lines. Land restrictions on two other sides of the site also required innovative applications of traditional methods. The Olive 8 project has won three state and local awards for innovation and has been reported on in Engineering News-Record and has been the subject of two feature articles in the Seattle Daily Journal of Commerce. This paper presents the conditions and site challenges, reviews the design analysis, discusses the shoring performance, and looks at other potential applications.

Jan 1, 2009

By Michael Arnold, Bob Faulhaber, Joe Nichols

"Center Hill Dam is a critical part of the infrastructure controlling floods at the Caney Fork River and reducing flood levels at the Cumberland, lower Ohio and Mississippi Rivers. The Center Hill Dam Foundation Remediation Project was necessary to address Karst features in the foundation rocks and observed signs of distress of the dam. From 2011 to 2014 BAUER Foundation Corp. (BFC) performed deep foundation works for this project. The executed features of work include the installation of two walls. The first wall extends throughout the clay embankment into the underlying rock to provide encasement during the construction of the second wall. Its width of 7.4 feet makes it the widest diaphragm wall ever installed. The second wall is the actual seepage barrier and provides a continuous 2- feet wide wall. It extends through the first wall into the underlying rock and is up to 300 feet deep. The paper introduces the project, the requirements specified by United States Army Corps of Engineers (USACE) for encasement and barrier wall and the approaches taken by BFC. It discusses the ground conditions and describes the excavation equipment as well as the excavation methods used. A special focus is put on the steering capabilities of the hydrocutter equipment and the verticality performance.PROJECTBeginning in 2011, BFC was tasked by the USACE with the installation of a seepage barrier/cutoff wall at the Center Hill Dam Foundation Remediation project under a partially performance based specification. The remediation was necessary due to karst features in the foundation rocks and observed signs of distress, which led USACE to rate the dam with the most critical dam safety action classification (DSAC I). The executed features of work include the installation of two walls. The first wall, an encasement wall, extends vertically through the clay embankment and is embedded minimally into the underlying bedrock to provide embankment stability during the construction of the second wall, the barrier wall. The encasement wall is constructed of overlapping panels 7.4 feet (2.25 m) wide, which is the widest diaphragm wall ever installed, and up to 210 feet (64 m) deep. The second wall is the seepage barrier and provides a continuous 2 feet (0.6 m) wide wall consisting of overlapping panels. It extends through the encasement wall into the underlying bedrock and is up to 307 feet (93 m) deep. BAUER BC40 and BC50 hydrocutters mounted on MC96 and MC128 foundation cranes were used to perform the majority of the works (Figure 1). Excavations were performed under bentonite slurry (encasement wall) and water (barrier wall) and concrete was poured with the tremie method. Adding to the challenges, the project had to be executed in an environmentally sensitive area. Based on the high risk, a special focus was put on monitoring, quality control and geometric accuracy. The WallTracker information management system was used to share all relevant data between BFC and USACE (Roff et al. 2014)."

Jan 1, 2017

By Mohamad Hussein

Low strain dynamic tests are performed to evaluate the structural integrity of driven or cast-in-place concrete piles. This type of testing requires minimal pile preparation, and is simply performed by attaching an accelerometer to the pile head and striking the pile head with a hand held hammer. The measured data is processed by a dedicated system, inspected for wave reflections, and interpreted based on one dimensional wave propagation theory. Piles are normally tested shortly after installation so that problems can be identified early and corrective measures taken before construction of the superstructure. However, evaluation of existing foundations is occasionally required. Often, pile installation records are not available rendering impossible any rational foundation reanalysis. This paper discusses three case histories where low strain dynamic measurements allowed determination of pile lengths and structural integrity under existing structures where pile heads were not accessible.

Jan 1, 1992

By Gordon King

The City of Atlanta Water Department required the construction of a two sludge tanks and a wet well at the existing Chattahoochee Water Treatment Plant. Western Summit won a design build contract to build the project and proceeded to evaluate the wet well size options, and construction procedures. The final design required the construction of a 1 million gallon tank. The proximity of the underground tank to adjacent roads and existing plant structures ruled out laying back the excavation. As a result a tied back sheet pile retaining wall was initially proposed.

Jan 1, 2003

By Y. G. Li

The design and construction of the hand-dug caisson pier foundation of the Shenzhen International Trade Centre are described in the paper. In addition discussions and inquires about the load-bearing capacity of the hard bedrock are offered.

Jan 1, 2010

By Matthias Baeßler, Markus Herten, Ernst Niederleithinger, Steven Georgi

"Abstract: BAW and BAM have performed a large scale comparison and calibration test on static and dynamic load capacity evaluation of bored piles in glacial sandy soil. The test was performed using eight piles at the BAM test site for technical safety at Horstwalde 50 km south of Berlin. The test area has been prepared and investigated in great detail using boreholes, cone penetration tests, pore pressure sensors and geophysical methods to assure controlled conditions for all piles and tests. The piles (10 m length, 0.9 m diameter) are mainly friction piles (low toe resistance) and have been checked by integrity testing. Five piles have been tested by five contractors using the dynamic method in a blind experiment, the other ones piles by static load and/or later on by the dynamic method. Some piles have been equipped with additional fibre optic instrumentation which proved to be robust and helpful in interpreting the results of static, dynamic and integrity tests. We have experienced a deviation of the dynamic load test results gathered in the blind experiment from the static values of up to 20% in most cases, sometimes even up to 30%. This can be related to the known soil inhomogeneities, interpretation and modelling in CAPWAP and method inherent uncertainties. In cases where the static values were known by the testers for calibration, the deviations were significantly smaller. It has to be taken into account, that the two static load tests showed different results as well. Due to the low toe resistance, use of a big drop weight (11 tons) and large drop heights most piles suffered from cracking, which was clearly seen in follow up integrity tests and confirmed by excavation. The piles are available for further research.IntroductionBored piles are used in many construction projects of the German waterways authorities, e. g. bridges, piers or locks. Their load carrying capacity varies with pile type and geometry as well as soil type, parameters and structure and is thus not easy to calculate in advance. Dynamic pile testing as a cost effective addition or replacement for expensive load tests is accepted in many places (Beim and Likins 2008) but still doubted in others. Inspired by the international prediction event for piles in residual soil carried out in the frame of ISC’2 (Viana de Fonseca and Santos 2008), governmental research institutes have designed an experiment in a geological setting typical for glacial and post-glacial areas in northern Germany. Some results have already been presented by Niederleithinger et al. (2012), Herten et al. (2013) and Baeßler et al. (2013). It was intended to perform a blind test for load capacity estimation using dynamic pile testing on six drilled shafts involving five test crews. Two other piles would have to be tested thereafter using static and dynamic methods."

Jan 1, 2014

By Andrew Peterson

The Maine Department of Transportation offered this challenging design-build project for a new, 12-span, bridge over the Kennebec River in Bath, Maine. This structure would be built to replace the existing Carlton Bridge connecting the village of Bath, Maine to neighboring Woolwich, Maine. The design build team of Flatiron Structures, Inc., and Figg Engineers, Inc., elected to design and build a segmental concrete bridge. Site conditions dictated that this bridge would be supported primarily on deep foundations. Case Foundation Company joined the project team in the winter of 1997 to install twenty-two, eight foot diameter drilled shafts. The drilled shafts were designed with 8' diameter, permanently cased shaft sections and 7.5' diameter rock sockets. Shaft lengths ranged from 20' long near the river's edge to 100' deep in the middle of the river. Rock socket lengths ranged from 12' to 30' deep. Two Osterberg Cell load tests were conducted on production drilled shafts. Figg Engineers utilized the results of the load tests to "fine-tune" the rock socket design during construction of the drilled shafts. Construction of the drilled shafts proved to be very challenging and called on every member of the design-build team to work together throughout the project. One of the most challenging aspects of this project was in the installation of the 8' diameter permanent casing and drilling of the rock sockets. Early in the project, it became apparent that the top of bedrock was broken and unstable. This condition limited the advancement of the permanent casing and the affect of a "seal" at the top of rock socket. As a result, as the rock socket was advanced, loose material spilled into the hole and stopped progress of the socket. In order to resolve this problem, the design-build team developed a redesigned drilled shaft which included the installation of a steel sleeve to seal off the unstable rock formation. Following installation of the sleeve, the rock socket diameter was reduced to 7' diameter and advanced additional length to achieve required design capacity. All drilled shafts were installed with equipment supported on floating barges. Water access, along with the long shaft lengths and very hard bedrock required the use of cranes and drilling equipment that far exceeded the requirements of typical drilled shaft projects. This paper will discuss the relationship between design, construction, and equipment utilization on this challenging design-build project. [ ]

Jan 1, 1999

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 David B. Paul

"ABSTRACTThe US Army Corps of Engineers (USACE) has 704 dams in their inventory and over 100,000 miles of levees with a capital value of over $150 billion. Currently, there are 319 dams that are classified as high hazard and have actionable failure modes that will require structural modifications. The most frequent actionable failure mode associated with the inventory is seepage and piping. One of the most effective engineering solutions is the installation of a cutoff to limit seepage. Currently, USACE has over $1.5 Billion of cutoff wall projects under construction and/or design. Given the magnitude of the dam and levee safety issues, USACE is developing a new Engineering Manual (EM) titled “Seepage Control Cutoffs for Dams and Levees.” This EM covers all of the methods to construct cutoff walls. USACE has partnered with the Deep Foundation Institute (DFI) in preparation of the EM to ensure that it is comprehensive and draws from the expertise of the specialty foundation engineering companies that design, manufacture, and construct seepage control cutoffs around the world. The EM contains case histories as well as a comprehensive project statistical summary and guide specification paragraphs. The goal of USACE was to make the EM a state of the art document for use by Districts.HISTORYSlurry wall construction techniques were developed in the late 1940’s in Italy by ICOS. The first use of the slurry trench method of construction in the United States was by the USACE Memphis District in September 1945, to form a partial cutoff along the Mississippi River levee on the Arkansas side of the river just below Memphis, Tennessee. The idea for the project probably evolved from the use at that time of puddle clay trench cutoffs combined with the use of drilling mud for advancing borings. A paddle wheel mixing device was constructed for making slurry from native clays. Trenches were dug to a 20-ft depth using a trenching machine and to a 35-ft depth using a dragline with a 100-ft boom and 2-cu-yd bucket. Backfill was mixed in windrows at the site from hauled-in clay gravel and native materials and pushed into the trench by a bulldozer when the length of the trench was equal to about twice the trench depth. It is amazing that after almost 70 years, the technique is still about the same as it was when first developed by the Memphis District. A soilbentonite cutoff was constructed under the Kennewick Levee adjacent to the Columbia River as part of the McNary Dam Project in Washington by the Walla Walla District in 1952 The first application of a soil-bentonite slurry trench cutoff for control of underseepage at a major earth dam was at Wanapum Dam on the Columbia River in Washington in 1959.The first cement- bentonite cutoff in the United States was constructed at the Tilden Tailings Project to store tailings from the Tilden Mine in Michigan in 1976. The first cement-bentonite cutoff constructed at a dam on a river retaining a reservoir in the United States was completed in 1978 at the Elgo Dam (formerly the San Carlos Dam) in Arizona.The USACE has designed and constructed some of the deepest and most complex cutoff walls for dams since the 1970’s. The first major concrete panel cutoff wall constructed in a dam in the United States was at Wolf Creek Dam (Nashville District) by the ICOS Corporation between 1974-77. The dam has a long history of seepage issues associated with the karst geology that comprises the foundation. In 1968, about 17 years after first being impounded, wet areas, muddy flows in the tailrace and sinkholes in the downstream toe adjacent to the switchyard occurred."

Jan 1, 2014

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 Jim Steding

L.G. Barcus and Sons, Inc. recently completed a three-phase project for the expansion of Presbyterian Hospital in Albuquerque, New Mexico for McCarthy Construction Co., the Construction Manager for the project. It was a challenge that allowed Barcus to demonstrate many of it's strengths. Safety of people and property, restricted access, low headroom conditions, extensive planning to maintain hospital operations and a tight schedule were all key elements affecting the successful installation of the Augered Cast-In-Place Piles. Phase I began with installing and performing a 450-ton pile load test on an 18-inch diameter Augerpile 65 ft long. The load test was installed and performed directly in front of the Emergency Room entrance. Space was limited and the E.R. had to remain open with uninterrupted ambulance access. The results of the load test were outstanding. In fact the test pile performed so well that some of the job piles were shortened from 75 ft long to 65 ft long. [ ]

Jan 1, 2003

By W. F. Van Impe

The design of piles and of pile groups has remarkably progressed over the past two decades. The in­creasing complexity of the building concept implements a more rational approach of the deep foundation capacity and its interaction with the structure. Moreover, the understanding of the soil characteristics relevant to deep foundation behaviour, is continuously in progress because soil parameters are always more accurately determined; which also contributed a lot to the recent developments in pile capacity design. At last, due to the increasing sensitivity of buildings to deformations, continuous attention must be also paid to pile group settlements. The aim of this report is to discuss some of the mentioned more important pile design developments.

Jan 1, 1994