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By S. T. Kok

This paper presents a case study in West Malaysia for passive piles failure in very soft marine clay in open excavation. In this particular case, the thickness of the very soft marine clay ranges from 5 m to 7 m (16 ft to 23 ft) from the ground surface. Preliminary site investigation reported SPT ?N? value of zero for the very soft marine clay. The design was based on a deep foundation utilizing driven piles to support the superstructure. During pile cap construction, the piles were subjected to uncontrolled open excavation, inducing bending moment in the piles, resulting in some cracked and broken piles. Analyses were carried out using an existing three-dimensional finite element code with a non-linear soil model to predict the response of these piles during excavation. Finally, the predictions of pile responses during excavation were compared satisfactorily with the observed results.

Jan 1, 2009

By Shuvranshu K. Rout, Anup K. Mandal, Biswajit Das, Manos De

"To adopt new technology advancement in Steel Plant, there is a requirement of shifting of operation process from Coke Wet Quenching (CWQ) to Coke Dry Quenching (CDQ). New CDQ chamber foundation with deep basement and underground conveyor tunnel are to be constructed in an operating plant where heavy foundations and structures are located in close proximity. Furthermore, the existing CWQ system will be in operation during new underground construction and erection. Challenges to deep excavation of tunnel and chamber foundation consist of non-uniform ground condition, prevent washing out of soil from bottom of existing foundations, stability of existing nearby structures, presence of large number of underground utilities, ensuring safe underground workplace to construction resources engaged in new construction work along with project schedule and budget constraints. A combination methods involving use of soil nailing, soil grouting, contiguous bored pile and micro pile had been adopted for protection of excavation sides as well as existing structures. Each side of excavation in different stretches were analysed during design as well as construction stages. The use of combination of all techniques in a single brown field project in context of the nature of site constraints and safety issues made this a unique project.INTRODUCTIONSteel Industry is one of the backbones of industrial growth of any developing country like India. Due to increasing land prices most of the steel plants in India are expanding within their existing plant facilities. In addition to that, there is demand of adoption of new technology for future expansion projects to set new benchmarks with global standards.The property owner had earlier installed a Coke Wet Quenching (CWQ) for their Coke Plant. Now, there is a requirement from process department to proceed with Coke Dry Quenching (CDQ). To facilitate the CDQ within the existing CWQ which will be in operation is the main challenge for the property owner. The second challenge is the limited space for underground construction and subsequent equipment erection within the stipulated time frame.From a geotechnical prospective, the project team had uncertainty and reservations in their mind about the construction methodology. Therefore, the role of three “C”: ‘Consultant’-‘Client’- ‘Contractor’ and their combining brainstorming is essential to freeze a working plan for achieving the goal. In this paper, only the excavation support systems for underground foundation structures have been highlighted in the context of solving geotechnical problems."

Jan 1, 2017

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 Allan Sylvester

This paper will discuss the design, construction, and performance of the support of excavation on the San Diego State University LRT Station. The vertical elements of the system include drilled secant piles and drilled soldier piles. We will discuss the geo-technical characteristics, design and construction considerations, loading criteria, construction techniques, schedule constraints, and performance of the pile and support of excavation systems. In consideration of the conference theme, there will be a discussion of the successful accomplishment of meeting the interim milestone dates of the Contract. The project team cooperatively worked to design and install approximately 1,100 drilled secant and soldier piles as well as excavate and install the balance of the support of excavation elements in such a manner as to minimize the disruption to campus students and operations.

Jan 1, 2002

By James A. Schneider

Selection of resistance factors within Load and Resistance Factor Design (LRFD) requires accurate assessment of uncertainty and bias in load and resistance. To date, many studies have focused predominantly on the assessment of uncertainty, while the potential for bias appears to be the dominant factor in design for consistent levels of reliability under a variety of situations. Bias comes from factors which have been ignored in design method development but significantly influence resistance when extrapolating from conditions typical of databases to those at a given site. Uncertainty and bias can be quantified as the coefficient of variation and mean (or median) of a data set, respectively, for statistical assessment of load and resistance factors. This paper first presents an overview of statistical assessment of resistance factors, and then discusses factors that influence uncertainty and bias when extrapolating to situations outside of conventional databases of driven pile axial capacity.

Jan 1, 2009

By Pierre Gouvin, Michael Oakland

"This paper covers the rapid response methods used to monitor the emergency response to damage to an historic structure. An architectural gem, the latest incarnation of the old south Church was completed in 1875, utilizing local conglomerate (pudding stone), combined with brownstone and other materials to make an incredible showcase for priceless stained glass and other details epitomizing the height of the American Industrial Revolution. As part of required American with Disabilities retrofits to the adjacent Metropolitan Boston Transit Authority Station (MBTA), a support of excavation system was implemented with tradition sheet piles. During excavation (SOE) it was determined that Jet Grouting would need to supplement the sheeting to close openings in the SOE. During Jet Grouting, the eastern side of the structure was bisected, and lifted over 2 inches up and to the south. The movement occurred rapidly, within minutes, and subsided when Jet grouting was discontinued. The paper will describe the nature of the immediate response to get a real time monitoring program established, and the follow on monitoring program that ensued to provide the needed information to the stakeholders about this critical structure to evaluate stability, safety and to develop a long term remediation plan. The real time systems and instruments used consisted of Automated Motorized Total Stations (AMTS) and Automated Crackmeters. The Paper will describe the techniques used to control construction in safe manner.INTRODUCTIONThe Old South Church of Boston was constructed in 1875 and is one of the best examples of High Victorian Gothic Architecture in the Northeast. (Fig. 1) shows the newly constructed Old South in 1882. The Roxbury Conglomerate used to construct the church combined with large stained glass window by Clayton and Bell of London provides its unique appearance. Like most of the structures constructed in Boston’s Back Bay at that time, the church is founded on timber piles which penetrate the fill and organic soils to bear in the upper Boston Blue Clay. The churches interior includes high vaulted plaster ceilings and a 1920’s E. M. Skinner organ with exposed pipes as long as 32 ft. in length. The Church was added to the list of National Historic Landmarks in 1970 and is a featured Boston attraction."

Jan 1, 2017

By P. V. Chandramohan

"In ports, piled berths are designed and constructed for berthing of ships with a finite draught. Piles in a bridge foundation also have a large free stand above scoured level. The piles of these structures have to withstand large horizontal forces imparted by the impact of the approaching vessels or due to longitudinal and transverse action in a bridge. It is also imperative that these piles have to project out of the dredged / scoured bed. These piles are normally designed as slender compression members subjected to bending also. They are subjected to vertical load tests for assessing the soil resistance. Lateral load tests, as a rule, are also stipulated. IS and IRC codes stipulate a deflection criteria for lateral load test to arrive at the capacity. These tests are usually conducted on a working pile by jacking out two piles. At the time of the test, pile will be free headed. But in service, piles are fixed head. There is a large difference in deflections between a fixed head and a free headed pile. Besides, a free headed pile will be subjected to a much higher bending moment than the fixed head one. This will put the working test pile under risk of breaking during the test. The problem is analyzed with case studies. INTRODUCTION Vertical capacity of piles is assessed by static formulae. This formula is based on the soil properties obtained from random soil exploration and laboratory and in-situ testing. Since soil is not a homogeneous medium, properties can vary. The design parameters taken for computations may be different from the ones at the interface of the pile with the soil. The best way is to find out is by a load test. The code IRC:78-2014 has rightly stated that initial load test is part of the design process. This is true with the vertical load test. But there are certain problems with the purpose and inference of the lateral load test. In both the tests the criteria for acceptance is the quantum of movement of the point of application of the load. In the former, the movement is vertical and depends more on the compression of the soil than the compressive strain in concrete. But in the latter, this movement is partly on account of the flexural rigidity of the pile and partly due to the horizontal compressibility of the soil. The role of rigidity of the pile is more when compressibility of the soil is higher. Lateral load test is done by jacking one pile against another because it is difficult to get an independent horizontal reaction. Please see Fig.1 Photo."

Jan 1, 2015

By G. Tamaro

The World Financial Center is situated on a 60,000 square meter site at Battery Park City at the southern tip of Manhattan Island. The foundations for the buildings and the related infrastructure posed difficult design and construction problems since the site was filled land in the Hudson (North) River. Foundation construction was made difficult by both the geology and the existence of two railroad tunnels which passed under the site. The soils at the site were unsuitable to support construction of heavy structures, and as a result, all of the foundations had to be carried down to bedrock, or the glacial till over rock. Two buildings were supported on piling and special battered caissons which provided lateral support against wind loading. The other two buildings were supported directly on rock, requiring excavation to depths of 19 meters (63 feet) below grade.

Jan 1, 1989

By J. M. N. P. C. Teles, Venda Oliveira P. J., Correia A. A. S.

"AbstractA laboratory work was performed to study the mechanical behavior of a Portuguese soft soil chemically stabilized with binders and reinforced with metallic fibers when subjected to tensile stresses. To this end and in order to compare the tensile strength results done by two different tests, there were conducted two types of experimental tests: Tensile Split Strength Tests (TS) and Direct Tensile Strength Tests (T). The samples tested had the same binder quantity and different fiber contents, which allowed the characterization of the tensile behavior of the stabilized and reinforced soil, as well as the definition of the best fiber content. Results show that the binder is the main parameter controlling the behavior of the stabilized and reinforced soil until failure, while the influence of the fibers is noticed mainly at the post-failure behavior. The comparison between the tensile strength done by T and TS tests shows that the tensile split test can be used to estimate the tensile strength, although its results are lower than those obtained by the direct tensile tests in general.IntroductionDue to its poor mechanical characteristics, the construction on soft soils presents difficulties that require the use of soil improvement techniques such as chemical stabilization. However, even when mixed with binders, the tensile strength of the stabilized soil is poor, requiring, in certain cases, the use of expensive steel reinforcement or metallic beams, with obvious impact on the final cost of the work. Thus, for the cases where the tensile strength is a design requirement, the soil stabilization should be design with another element, whose primary role is to give tensile strength to the improved soil (Teles 2013).To fill the lack of published studies focused on soft soils both chemically stabilized and reinforced with metallic fibers, the present research aims to analyze the behavior of the improved soil when subjected to tensile stresses. To support the research there were conducted direct tensile tests (T) to directly measure the tensile strength of the samples and tensile split tests (TS) or Brazilian tests to obtain it indirectly. The samples tested had the same binder quantity but five different fiber contents in order to study the influence of the fibers in the improved soil behavior. In addition, a comparison between the results of both tests was made."

Jan 1, 2014

By Leonardo Massone

The p-y method is one of the most popular methods in pile design and has been calibrated for various boundary conditions using numerical and experimental studies during recent years. Most studies on reinforced concrete (RC) piles have included the impact of flexural nonlinearity, (e.g. nonlinear moment?curvature relations) but not considered associated pile shear deformations when deriving p-y curves from field data. Common p-y curves may be better applicable for piles with flexure dominated failures (e.g. piles with free- head boundary conditions). For piles with fixed head boundaries (i.e. rotation restrained piles) shear deformations could be of significant influence. To study this problem, a coupled shear flexure interaction model for axial-bending-shear behavior coded in OpenSees was applied to a 0.61 m (2 ft) diameter flagpole and a 0.61m (2 ft) diameter fixed head pile specimen to investigate the possible influence of shear deformations to the overall pile responses. The surrounding soil was represented by p-y curves derived from prior large scale testing on piles with similar boundary conditions. Analysis results show that for flagpole piles, shear forces and shear deformations were insignificant. Considerable contributions of pile shear displacements and forces were observed for the fixed head pile, with shear displacements contributing up to 40% of the total pile displacement. Results suggest that nonlinear shear deformations for reinforced concrete piles should be considered for fixed-head or similar conditions, and that currently used p-y curves may underestimate the actual lateral pile displacement and possibly lead to unsafe design for the particular boundary condition.

Jan 1, 2012

By John E. Lens

Minutes after the Friday afternoon October 16, 2009 announcement that the 80 year old Lake Champlain Bridge was closed to traffic out of concern for public safety, emergency detour planning started at VTrans and NYSDoT. The closure severed a cross-lake link between Addison, VT and Crown Point, NY, which created a 76 mile detour and significant hardship for commuters, farmers working on both sides of Lake Champlain, and businesses relying on both traffic and employees commuting between Vermont and New York. Rehabilitating the bridge was determined to be economically and technically unfeasible and the design of a replacement bridge was accelerated for a spring 2010 construction start. In the meantime, a temporary ferry alternative was to be rushed into service beside the original bridge by February 2, 2010. This paper presents the case history of the fast-tracked ferry dock design and construction on the Vermont side. Twin 300-foot-long pile supported approach spans, a loading slip system and ice deflectors were designed, fabricated and constructed in 90 days in the fall/winter of 2009-2010. This chronicles the project from initial concepts through the extraordinary cooperation between state and federal agencies, and near round-the-clock winter construction on Lake Champlain. This project and its companion project on the New York shore succeeded by virtue of exceptional cooperation between seasoned regulatory, design, and construction participants and warrant this case-history presentation of the Vermont project to share within the industry as an example of overcoming extraordinary challenges.

Jan 1, 2011

Jan 1, 1998

By Jean-Louis Briaud

The following is a summary of a very recent report prepared at Texas A&M University for the National Cooperative Highway Research Program and entitled "Downdrag on Bitumen Coated Piles". Anytime the soil settles more than the pile, downdrag or negative skin friction will develop. The load in the pile increases with depth up to a certain point and then decreases down to the pile point. This phenomenon has been quoted as being the number one culprit for deep foundation failures. In Chapter 1, an introduction to downdrag is given. The most common criterion for downdrag is to consider it in design as soon as the settlement of the soil surface after pile driving exceeds 0.5 in. Coating piles with bitumen is an effective way of reducing downdrag forces and therefore allows to use smaller piles for the same load. This results in cost savings. Coating piles with bitumen increase the cost of piles by about 33% and therefore the decision to use bitumen is generally based on economic considerations.

Jan 1, 1989

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 Yukihiro Ishihara, Nanase Ogawa, Ming Lei

"Abstract In the Press-in Method, a static jacking force is used to install a prefabricated pile, while a reaction force is gained from previously installed piles. This piling technique has solved problems in urban piling construction such as noise and vibration associated with the piling work, restricted construction conditions due to the existing structures, and so on, since its emergence in 1975. Its applicability to hard ground conditions has been improved, with the development of press-in machines that involve augering or rotation. Besides, information such as time, penetration depth, jacking force and rotational (or augering) torque in piling work are automatically obtained. The concept of PPT, Pile Penetration Test, has been developed by the authors, to apply the obtained information to the processes of construction planning or foundation design. This paper highlights the technique to estimate SPT N value from data acquired in standard press-in (press-in without any auxiliary methods), press-in with augering and rotary press-in. The technique will be helpful in assuring the adequate embedment depth, re-selecting the adequate press-in machine or auxiliary method, and re-pricing the project objectively, particularly when a contractor encounters unexpected ground conditions.INTRODUCTIONThe Press-in Method is one of the piling techniques that use a static jacking load to install piles. It mitigates environmental problems of noise and vibration that have been associated with other conventional piling techniques.It is also featured by its spatial efficiency; since a ‘press-in’ piling machine gains a reaction force from the previously installed piles, there is no need of bulky weights that will occupy a large space. This feature is emphasized in the piling system in Figure 1, where a press-in machine and its related devices are all positioned and ‘walk’ on top of the pile wall.Its applicability to hard grounds has significantly been improved, with some newly developed piling machines that involve augering or that install tubular piles with teeth on the base by applying axial load and rotational torque at the same time."

Jan 1, 2014

By J. O. Osterberg

The realities of foundation enginering are that the work never proceeds exactly as expected. The various reasons, exploration, design, construction, and legal are discussed. Case histories are presented with an analysis of why the projects did not turn out as expected and how the difficulties might have been avoided.

Jan 1, 2010

By Ramin Motamed, Joseph A. W. Toth

Evaluation of the capacity of large-diameter drilled shafts using current load test methods present challenges when considering the magnitude of loads required to fully mobilize their capacities. Often, these full scale tests do not fully mobilize the capacity through side resistance. Therefore, the need for innovative solutions to extrapolate side resistance and interpret nominal capacity are of key interest. In this study, we evaluate three methodologies for extrapolating unit side resistance based on bi-directional load test data. Fellenius (2001) presented these methods for interpretation of pile capacity using static load tests. Our interpretations are based on the evaluation of 116 load tests. Unit side resistance was calculated and reviewed for each load test and categorized using three criteria of mobilization; (A) full, (B) partial and (C) linear. This study specifically focuses on load tests that showed fully mobilized unit side resistance behavior (Criteria A). The three methodologies were applied assuming Criteria (A) load tests were mobilized to 50% of their measured values. Subsequent comparisons of each extrapolation were then compared against the full measured values for each test and generally showed good agreement. INTRODUCTION It is widely accepted that conducting load tests such as standard top-down tests or bi-directional (i.e. O- cell) tests can help designers understand load-settlement behavior and the nominal resistance of drilled shaft foundations. These load testing methods provide the advantage of confirming design assumptions as well as improving the reliability of the foundation design. The potential cost savings from the application of these methods for mid to large size projects is self-evident. For example, in a recent project in Northern Nevada, an O-cell test on a 6.9 ft diameter, 114.8 ft length drilled shaft imposed an initial cost of $125k to the project, resulting in a 15% reduction on the total foundation cost; equivalent to $1.3 million in overall savings (Pease, 2014). However, the costs of implementing such methods on smaller projects can be prohibitively expensive (Hagerty et al, 2016). Despite the clear advantages of drilled shaft load testing, the current practice is not without limitations. Performing load tests on large-diameter drilled shafts with high capacities is a challenge considering the significant loads required to fully mobilize the capacity of such foundations. In some cases, the feasibility of these tests is impractical because the associated initial cost is not guaranteed to outweigh the final savings. As a result, large scale load tests are sometimes ruled out from the design phase of projects. Furthermore, in the majority of load tests the magnitude of loads applied are specifically selected to not approach failure, so the shafts can be used in the future foundation system (i.e. production shafts). This practice of field testing restricts our knowledge of the true capacity of the drilled shaft at failure; hence the nominal resistance remains unknown.

Jan 1, 2018

By W. Tom Witherspoon

Many Engineers are skeptical and cautious about skin friction factors for the portion of drilled piers where temporary casing is used. This has led Texas engineers in many cases to eliminate skin friction values for the cased section, which necessitates deepening the drilled shaft to compensate for the loss in the cased section. This paper has provided field test data that supports inclusion of skin friction in the temporarily cased hole section as a contributing factor in total axial capacity as comparable to open hole shafts of the same diameter. Reasons for the resultant friction values are provided including; remolding of the cased clay section and the increased pier circumference necessitated by the oversized casing required for adherence to the engineers shaft diameter specification.

Jan 1, 2009

By J. Hartikainen

Kemi cardboard mill is founded on the alluvial bed of Kemi river at the north-eastern cost of Botnic Culf in Northern Finland. The alluvium consists of sandy and silty layers underlain by thick medium dense silty moraine layer. The first cardboard machine, having a belt width of 7,4 m, was constructed in 1972 on 7,5 to 9,5 m long wedge-shaped precast driven piles. Because of the excessive differential settlements and sometimes unexpected dynamic malfunctioning of the machine it was decided to strengthen the foundation before installing the partly new machine and increasing the running speed from 500 to 750 m/min. Piling was done under extremly strick limitations concerning space, vibrations, settlements, dust etc. Extra vertical support was made by using 23...25 long x-form steel piles driven by compressed air pile hammer down to rock. The piles were held together with old piles by a conctrete frame with diagonals, which made the total system - machine - foundation frame, piles and ground - ridgid enough to avoid resonance during dynamic loading.

Jan 1, 2010

By R. Bellotti

The theory of cavity expansion in an infinite frictional soil mass whose strength is represented by a curved Mohr-Coulomb failure envelope has been used to predict with some confidence the cone resistance of a clean dry sand. Experimental data were obtained from cone penetration and pressuremeter tests on two sands, conducted in a large calibration chamber (CC) under carefully controlled placement and boundary conditions. A plane strain bearing capacity theory was developed, and to convert the results to axi-symmetric conditions, an empirical "shape factor" was used. In the paper, the theoretical background, experimental data, calculation procedure, and the results of the analysis are presented. In general, a reasonable validation of the cavity expansion approach to the bearing capacity of deep foundations has been obtained.

Jan 1, 1987