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By Eric S. White, Thomas J. Sabourin, Khuram R. Mohib

"This paper presents the challenges associated with the design and construction of a steel sheet pile cofferdam supported with one level of grouted anchors in clean to silty sand with gravel. The initial assessment of the subsurface conditions indicated loose to medium dense soil with intermittent dense to very dense layers with no occurrence of cobbles and boulders. Sheet piles were proposed to be installed to a depth of 24 m below the ground surface to limit dewatering requirements for the cofferdam. During sheet pile installation, refusal of piles occurred at multiple locations forming passages for increased flow into the cofferdam. Modifications were made in the design of the dewatering system as a result of the increased flow. Finite element modeling was used to select the necessary modifications to the dewatering system within the cofferdam. Wells were installed based on the findings of the numerical model. Model simulations showed good comparison with monitoring of the field installed dewatering system.INTRODUCTIONIt is necessary to consider the impact of the ground water, subsurface stratigraphy, strength, and drainage behavior of the soil for the design and construction of cofferdams. This paper presents a case history of the construction of a cofferdam in Northern Ontario, Canada. The project consists of the construction of a powerhouse, intake, and tailrace which will generate around 28 MW of renewable clean energy by diverting water from New Post Creek through a power house and discharge into the Abitibi River. The focus of this paper is the dewatering and excavation support required to permit construction of the powerhouse. The layout of the cofferdam is shown in Fig. 1. The cofferdam for the powerhouse is rectangular in shape with sheet piles on all four sides intended to be driven to the design toe El. 101 m. The east and west walls have a length of 46.3 m. North and south sides are 47.6 m long; and in addition, two cantilever sheet pile walls bound the tailrace on the west side and two cantilever walls were installed on the east for construction of the penstock inlet. The ground surface in the powerhouse cofferdam area, before commencement of sheet pile driving, was brought to El. 125; the ground then slopes up to the East, toward New Post Creek, and the site is bounded on the West by the Abitibi River. 186 pairs of sheet piles were used to create the cofferdam and cantilever walls. The deepest excavation is to elevation 114.4 m. Within the west half of the cofferdam footprint, the base of excavation slopes upward at 3H: 1V to facilitate the tailrace discharge into Abitibi River.SOIL STRATIGRAPHYThe cofferdam design was based on the geotechnical investigation conducted by AECOM (2014) which included two relevant boreholes near the powerhouse footprint. The ground elevation at the time of investigation varied between 131 to 129 m. The material observed to the full depth of investigation was comprised generally of coarse to fine sand and gravelly sand or a sand matrix with gravelly inclusions. Some intermittent layers of clay and silt intrusions were also observed. Generally the soils grade finer away from the river. SPT N60 values were recorded in two borings during the field investigation with values reported from 3 to 92. The in-situ conditions ranged from compact to dense with some loose and some very dense zones. Figure 2 shows the variation in SPT N60 values with elevation."

Jan 1, 2017

By George Koenig

I have been granted the outstanding privilege... and pleasure to introduce you this evening to the Grand-Duchy of Luxembourg and to tell you in a few words how this country came into existence, how it managed to survive and what role it nowadays plays in the International Community. Luxembourg, situated between Belgium, Germany and Prance is a small, a very small country... just a dot on a map. After all, it is only a matter of 62 miles from top to bottom and 37 miles across at it's widest... barely covering some thousand square miles... so be careful about stepping on the accelerator... you might be in and out without having realized it... which would be a real shame as the Grand-Duchy enjoys a fairly unique geographical feature in so far as it provides the visitor with an outstanding variety of scenery concentrated in a minute spot.

Jan 1, 1987

By Per Eriksson

For light buildings on clay, foundations on L/C-columns is in many cases a competitive alternative to piles when the thickness of the clay is moderate (<20 m). The method is applicable for the above mentioned depth when the clay is normally consolidated, and for thicker deposits when the clay is overconsolidated at depth. This case study concerns a shopping mall in Nordby, Sweden, founded on L/C-columns (5-15 m in length) and generally spaced 1.45-2.0 m (spacing 0.7 m was used below pillars). The base slab was built as a raft foundation, using fibre reinforced concrete.

Jan 1, 2000

By S. D. Zhang

The first reinforced earth railway bridge abutment in China has been successfully constructed of September, 1985 under the supervision of the Reinforced Earth Researth Group of Shanghai Institute of Railway Technology. In order to verify the reliability of the designed structure and its behaviuors, the 1:10 reduced scale model tests in laboratory and field tests on the actual structure during construction were proceeded. Various loads of different positions were charged, the vertical and lateral earth pressure in the filling soil, the stresses developed in the reinforcements, and the deformations of the models or the actual structure were recorded in those tests. The behaviors recorded are presented and discussed in this paper.

Jan 1, 2010

By Jerry F. Parola

In current practice, pile foundation design is based on a general under-standing of pile-soil interaction during installation and superstructure-pile-soil interaction after construction. The pile design is a reflection of experience, precedent and judgment for normal piling practice of working load capacities up to approximately 100 tons with corresponding ultimate capacities up to 200 tons. For higher capacity piles, pile design is even less predictable. In particular, the feasibility of pile installation is an important design consideration that must be given the proper attention. An installation capability that is not given the required emphasis can cause unnecessary problems.

Jan 1, 1986

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 Darrell L. Beddard

The Loma Prieta earthquake occurred on October 17, 1989 at 5:04 PM, Pacific Daylight Time. It measured 7.1 in magnitude and was felt from Los Angeles north to the Oregon state line and east to western Nevada. The epicenter of the earthquake was located along the San Andreas Fault, in the Southern Santa Cruz Mountains just north of the City of Watsonville, California. It was the largest earthquake to occur in the San Francisco Bay area since the 1906 earthquake. A total of 87 aftershocks of Magnitude 3.0 or larger were recorded within 21 days after the seismic event. As a result of this earthquake thirteen State-owned and five locally-owned bridges were closed to traffic. Three of the most publicized State-owned structures closed to traffic were Struve Slough Bridge, San Francisco-Oakland Bay Bridge and Cypress Street Viaduct. Struve Slough Bridge was twin slab bridges that collapsed and were rebuilt and open to traffic three months after the earthquake. San Francisco-Oakland Bay Bridge experienced collapse of upper and lower spans at Pier 9 and was reopened to traffic one month after the earthquake. The Cypress Street Viaduct experienced collapse of 48 bents that resulted in the upper roadway falling onto the lower roadway.

Jan 1, 1996

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 Antonio Marinucci, Robin Mao

The new Hangzhou West Railway Station, which is currently in the early stages of construction, will be located in the city of Hangzhou, China. To accomplish the ambitious goals of the project, the construction work and station building was divided into three project areas. The original design utilizes 1,580 drilled shafts with diameters of either 800 mm or 1000 mm (32 or 40 inch) to support the new Station and its various ancillary structures. The drilled shafts will be tipped into the moderately weathered argillaceous siltstone a distance between 5 and 15 m (16.5 and 49 ft), resulting in an effective pile length ranging from 35 to 43 m (115 to 141 ft), respectively. For the first phase, approximately 550 production drilled shafts will be installed. Eight (8) sacrificial drilled shafts each with a diameter of 1000 mm (40 inch) were installed to a depth ranging from 50 to 57 m (164 to 187 ft), and were tested to confirm the design parameters used for the first phase, to evaluate the contractor’s installation means-and-methods, and to provide guidance whether redesign is warranted for the subsequent two phases. Bi-directional static load testing was performed using a donut-shaped Super Cell to apply unidirectional axial loads up to 13,200 kN (2,970 kip). This paper will describe the bi-directional testing and select results obtained therefrom. The axial compressive and uplift resistances determined from the testing verified that the available axial resistance of a single drilled shaft exceeded the minimum design requirements.

By Nikolas Schmitz

For today’s construction industry, large-diameter piles are common practice, as they are more competitive than drilling a larger number of smaller piles. More and more piles are installed by drilling rigs, replacing the installation by hammer, vibrators or caisson. Equipment capabilities and technics with rotary drill rigs are highly developed, but very costly and time-consuming when it comes to rock drilling, large diameters and deep foundations. Pile top drill rigs (PBA), based on reverse circulation drilling (RCD) technology, overcome these challenges and are an efficient solution for large diameter drilling (0.6 m to 8.0 m/19.7 ft to 26.3 ft) and drilling depths of up to 500 m (1,640 ft.)in various geological conditions onshore and offshore. The paper will explain benefits of RCD technology and prove this with figures from the Mumbai Trans Harbour Link project.

Nov 1, 2022

By Javaid M. Alvi

This paper is an attempt to outline the emergence of Augered Cast-ln-Place piles as one of the more economical types of foundation for supporting high-rise buildings and heavily loaded structures recently constructed in the flood plains in and around the Greater Pittsburgh area. To understand the process of selecting foundation types, it is important to understand the general geology of the area and past construction activities that have taken place in the flood plains, especially along the riverbanks, during the last century. The first part of this paper presents a brief description of the general geology of the area; the second part of the paper concentrates on the historical evolution of the use of deep foundations and selected case histories; and the last part presents the results of load tests on large diameter Augered Tremie Concrete (ATC) Piles placed in sandy alluvium which suggests a much larger load-carrying capacity of these piles and also provides an insight into their future application. 2.0 GENERAL GEOLOGY 2.1 Soil Overburden Most of the high rise buildings in the Central Business District as well as along the North Shore and South Side of Pittsburgh are situated in the flood plain at the confluence of the Allegheny River and the Monongahela River where their combined flow forms the Ohio River. The flood plain consists of unconsolidated deposits of Quaternary age that overlie the bedrock of Pennsylvanian age. These deposits are called alluvium or valley fill, and include moderately to poorly sorted clay, silt, sand, gravel and some boulders. Their thickness varies from zero at the edges of the valley to about 80 feet towards the rivers (Figure 1).

Jan 1, 2001

By Donald A. Bruce

The construction of major structures in karstic limestone terrains poses difficult problems to designer and contractor alike. This reflects the inherent variability of such conditions, and also the significant impacts caused by the construction processes themselves. Three case histories are provided of recent projects in the United States: the sealing of a major inflow into a quarry, the improvement of a highly loaded bridge pier foundation, and the installation of high capacity micropiles. Emphasis is placed on problem assessment and execution verification.

Jan 1, 2002

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 Geoffrey D. Collins

This paper deals with the construction of the Effluent Outfall Diffusers which form part of the outfall for the Deer Island sewage project. The work was executed 15 km out to sea in Massachusetts Bay and required the drilling, installation, grouting and accurate determination of the actual position of 55 riser shafts in 33.5 m deep water. Although not strictly a "foundation", the contractor&apos;s approach to the installation of the diffusers was a logical development from many marine foundation projects executed by the Contracting companies over the last decades. The only previous application of this design of outfall had been in Australia where offshore oil drilling techniques had been adapted for use in riser installation.

Jan 1, 1994

By José Carlos do Amaral, Marcelo Groszownik, Jorge Beim

"Initiated in 2008, the project of this 1800 km long Electrical Transmission Line is a job of extreme technical complexity, crossing regions of major forests and rivers. When ready, it will allow the large Brazilian states of Amazonas, Amapá and Pará to use the energy from hydroelectric plants, thus eliminating the need for the use of diesel fuel thermal plants, with their much larger environmental footprint. Due to its extraordinary characteristics, the Green Peace and the Discovery Channel constantly visited the job. The part between the Amazon and the Xingu rivers started in 2012, and encompassed about 100 transmission towers with up to 150 m height, through a region known as “Alagados”. This region exhibits a 1.5 m water level during the rainy season, and soaked ground the rest of the year. Navigation of regular vessels is impossible during the flood season, when a dense vegetation called “bulhado” fills the riverbed, and vehicle traffic is impossible during the dry season, due to the extremely low surface soil resistance. Great logistical and technical difficulties were encountered for driving and determining the capacity of the piles. New systems had to be developed for driving the piles, with the simultaneous use of 15 small piling rigs. The final penetration, total number of hammer blows during driving, plus Dynamic and Static Load Tests were used for determining the driving and acceptance criteria.The geographical challenge and initial conditionsThis paper describes the execution of foundations for a 500 kV Electrical Transmission Line in a region that becomes flooded during the rainy season and heavily muddy during the dry season. This is the monsoon climate, typical of the equatorial region of Brazil, where there is a rainy season lasting for about half the year, followed by a very dry season. The temperature varies very little throughout the year, due to the proximity to the equator. The locals call the rainy season “winter” and the dry season “summer”.The most important part of the so-called “Alagados” region is situated inside an Environmental Extractive Reserve (RESEX) called “Verde para Sempre” (Forever Green), created in 2003. This is one of the largest environmental reserves in Brazil. It is an area controlled by the Brazilian Environmental Control Department, the Chico Mendes Institute (ICMBio). The environment control parameters are very strict.No deep foundation had ever been executed before along the “Alagados” region. The main challenge faced on this job, however, was working in a place where self-propelling vessels or land vehicles and equipment cannot be used. During the rainy season there is a dense and intricate vegetation called “bulhado”, which prevents the movement of outboard motor boats with propellers going deeper than 50 cm. In the dry season, the heavy mud prevents the movement of foundation equipment, excavators, trucks and other machinery."

Jan 1, 2015

By Michael D. Justason

...a global perspective... In March of 2000, the Japanese Geotechnical Society added "Rapid Load Testing" to their national standard for pile testing. In the year 2000. it is estimated that there will be more than 500 "Rapid Load Tests" on foundations around the world. ...so what is a "Rapid Load Test", and why is it gaining acceptance and popularity?

Jan 1, 2001

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&apos; diameter, permanently cased shaft sections and 7.5&apos; diameter rock sockets. Shaft lengths ranged from 20&apos; long near the river&apos;s edge to 100&apos; deep in the middle of the river. Rock socket lengths ranged from 12&apos; to 30&apos; 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&apos; 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&apos; 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 Patrick Bermingham

This report presents the results of six STATNAMIC loading tests that were carried out on four different pile types at the CALTRANS 280 Test Site (Bridge No. 34-46) in conjunction with the Tension Pile Test Program. The STATNAMIC testing was performed by Berminghammer Corporation at the request of the California Department of Transportation, Office of Geotechnical Engineering. Others performed the static tension (uplift) and compression loading tests which werecarried out on the piles tested using the STATNAMIC method. A summary of the STATNAMIC test results is presented and discussed, and the appropriate results are compared with the static test results

Jan 1, 1993

By Harald Ludwig

In 2002, excavation support work commenced on the Capitol Visitor Center project located adjacent to the nation?s Capitol building in Washington, D.C. The outlying work (Slurry Wall Work at Main Site is not discussed) consisted of providing excavation support for a new truck tunnel approximately 1900 feet long up to 50 feet deep as well as support for the new underground auditorium and Library of Congress tunnel. The excavation support consisted of a combination of conventional drilled in soldier beams, lagging, tiebacks and braces; intricate underpinning inside the existing Capitol building; support of an existing Russell Tunnel; soil nailing and tiebacks underneath the existing Russell Tunnel; two temporary bridges; and a deep soil mixed wall with lateral support provided by braces. As part of an on-going research program, some of these braces were instrumented with strain gauges. The deep soil mixed wall was approximately 300 feet long and 65 feet deep on either side of the truck tunnel. Approximately 34,000 sf of deep soil mixed wall, 90,000 sf of conventional excavation support, 200 braces, and 320 tiebacks were installed. This paper describes the large scope and breadth of the project that required a variety of excavation support techniques. A few of the challenges in designing and installing the support of excavation are discussed. This paper also presents the results of the instrumentation program conducted on the deep soil mixed wall, which stood open for more than a year.

Jan 1, 2006

By Nino Catalano

The combination of two top levels of cross-lot braces designed and installed to act as a truss, and vertical post-tensioning of the panels allow the unbraced excavation of a 36&apos; span. Philosophy of Excavation Support System The excavation of interest is for the cut-and-cover box sections of the southern approach to the Third Harbor Tunnel, which is part of the Central Artery/Tunnel project in Boston, Massachusetts. The 60&apos; deep excavation is located very close to an existing building which is supported by piles, as shown in Figure 1. Therefore, it was necessary to minimize ground movement which may damage the building.

Jan 1, 1994