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By Bernard H. Hertlein

"When the Deep Foundations Institute (DFI) was founded, quality assurance and quality control (QA/QC) of foundation construction was rudimentary. Nondestructive testing (NDT) was a nascent technology, known to very few people, and very limited in its capabilities and applications. In the four decades since the DFI became a reality, NDT researchers and practitioners have taken advantage of technological advances to improve those existing testing and analysis techniques, and to create new ones that have all contributed to the engineering body of knowledge. This has enabled contractors to improve the quality and reliability of their products, and engineers to design more efficient foundations.Through its regular series of seminars, publications and annual meetings, the DFI has been vitally important in educating the deep foundations industry about the capabilities and benefits of NDT methods. In turn, NDT results have helped the industry identify problems in deep foundation construction, determine the causes of those problems, and improve design constructability and construction practices to increase the quality, reliability and efficiency of all types of deep foundations. This presentation reviews the evolution of several important NDT methods, and the contributions that they have made to foundation quality.THE BEGINNINGSThe Deep Foundations Institute (DFI) was incorporated in 1976 in the State of New Jersey as a 501(c)(6) non-profit association. The DFI is a consensus organization of Contractors, Engineers, Owners and Suppliers involved with the design and construction of all types of deep foundations. The purpose of the DFI was and still is to improve the planning, design and construction of deep foundations by educating all those involved, sharing best practices, and promoting the adoption of new technologies that improve quality, productivity or safety.This is well expressed in the current DFI Mission Statement: To bring together multi-disciplined individuals and organizations to find common ground and create a shared vision and a consensus voice for continual advancement in the deep foundations industry.At the time the DFI was born, nondestructive testing for verifying the quality and integrity of deep foundations was in its infancy, its growth constrained by the technology, or lack thereof. Some visionary engineers of the time understood the physics of the potential methods, and therefore the possible capabilities, but were frustrated by the lack of technology to work with. Electronic equipment was mostly analog, and the few digital data acquisition systems that were available had such slow sampling rates that they were incapable of recording rapid event sequences or short duration events such as those used in modern integrity tests. For example, Jean Paquet, a leading research engineer at the French National Construction Institute, (Centre Experimentale de Recherche et d’Etudes du Batiment et des Travaux Publics, or CEBTP) patented the frequency-based analysis procedure for the Transient Dynamic Response (TDR) method, aka Sonic Mobility or Impulse Response, in 1974, but it was not until 1977 that analog data acquisition systems became fast enough to turn his theory into a reality."

Jan 1, 2017

By Paul R. Lear

Sustainability continues to be an important aspect of remediation and infrastructure projects. Deep soil mixing (DSM), a common construction and remedial technology, can easily incorporate the following sustainability best management practices (BMPs), including Minimizing Total Energy Use and Maximizing Use of Renewable Energy; Minimizing Air Pollutants and Greenhouse Gas (GHG) Emissions and Maximizing Use of Machinery Equipped with Advanced Emission; Minimizing Water Use and Impacts to Water Resources; Beneficial Reuse of Materials/Reduction of Materials and Waste Reduction; Use of Local Labor and Supplies. This paper focuses on the sustainability of DSM treatment and provide carbon footprint calculations at least one completed DSM project which used these sustainability BMPs to demonstrate the environmental impact of the sustainability.

Sep 8, 2021

By Kyle L. Murrell

Along the southeast United States coast, clayey silt and silty clay marine formations may cause pile installation and integrity problems. More specifically, excess pore pressures which develop in these soils during driving can cause high displacement piles to rebound or ?bounce?. Bounce is defined as a large (¾-in. to more than 1-in.) downward pile displacement during the hammer blow with little to no net displacement at the end of the blow. Pile bounce can generate damaging tension stresses and result in inefficient pile installation. A case history is presented where pile bounce was observed during the installation of 20-in. square ?high displacement? prestressed concrete piles which support a new ferry terminal in coastal North Carolina. High-strain dynamic pile testing was performed during test pile installation to evaluate driving stresses, pile capacities, and hammer performance. During and after installation of numerous production piles, circumferential cracking was observed on some of the piles. Additional high-strain dynamic pile testing was performed on two piles installed with a hammer having a heavier ram than the initial hammer. The new driving system generated lower tension stresses and installed the 20-in. piles more efficiently. Low-strain integrity testing was performed on the piles to qualitatively assess the cracks and locate any unidentified cracks. The low-strain testing was performed on piles installed at least a week prior to testing and on piles installed immediately prior to testing. When low-strain testing was performed immediately after pile installation before dissipation of excess pore pressures, pile integrity could be evaluated to depths of at least 12 pile diameters deeper than when performed weeks after installation.

Jan 1, 2008

By K. Oshima

In Japan, earthquakes are experienced frequently. Many buildings and structures in Japan are supported on pile foundations. For these pile foundations, the joint section between the piles and footing (hereinafter referred to as "Pile Head Joint"), where the load of the superstructure is transmitted to the ground through the piles, is important in both the design and construction of works particularly under seismic conditions. This paper discusses the state in which the force is transmitted to the Pile Head Joint, and introduces the basic construction of the Pile Head Joint, based on experimental investigation. Steel pipe piles

Jan 1, 2010

By Anand J. Puppala

This paper provides information on various evaluation studies conducted to assess the CPT based interpretation methods. Salient findings from these evaluations are summarized. Additionally, a comprehensive evaluation study on both LCPC and European methods was performed on twenty-four driven piles selected from four different states. This evaluation showed that the LCPC method predictions are close to measured pile capacities. The European method provided good predictions for driven steel piles. Overall, both methods' predictions show high values of coefficients of variations, which are in agreement with other studies. Overestimation of driven concrete pile capacities is attributed to large estimations of unit point resistance. Suggestions to consider appropriate CPT based pile capacity interpretation methods are presented.

Jan 1, 2002

By Subhash B. Bhide

Deep foundations are affected by the presence of sulphates, chlorides, organic contents and water currents present in the soil. The sulphates in soil and ground water interfere first with setting of concrete. In long term, growing of sulphate crystals in concrete, crevices can spall the concrete. The chlorides mainly affect the steel. The organic content does not allow the concrete to set. It also reduces the compressive strength of concrete. The frequency and methods of sampling and testing for above corrosive elements are discussed. Presently available methods to avoid attack due to these corrosive elements are discussed. The stipulations by various codes are summarised. A method to assess the short term impact is elaborated with results of field studies. A tool developed to study the presence and effects of underground water currents on concrete is also discussed.

Jan 1, 1996

By David Coleman

This paper presents a case history involving the installation of drilled in piles with rock sockets for the Bicycle and Pedestrian Path project located west of the Henry Hudson Parkway within the Riverside Park between 83rd Street and 91st Street at the Hudson River in New York, NY. The paper specifically addresses access and construction procedures for a marine installation when working in an urban and environmentally sensitive setting.

"Full time inspection of drilled shafts by qualified personnel is a necessary part of construction. Detailed inspection procedures for routine inspection are provided in the Drilled Shaft Inspector’s Manual, published jointly by the DFI and ADSC: the International Association of Drilled Shaft Contractors.The use of NDT methods or other observation methods, such as probes, video camera inspection, remote shaft wall inspection devices or various calipers are not suitable substitutes for routine "topside" construction inspection as described in the Drilled Shaft Inspector’s Manual. However, these NDT and other "remote" or indirect observation methods are valuable alternatives to direct entry of personnel into drilled shaft excavations. They should be considered whenever appropriate to reduce the risks of direct entry of personnel into drilled shaft excavations.As described in the Drilled Shaft Inspector’s Manual, observations made during construction are essential for quality construction of drilled shafts. The shaft depth, diameter, plumbness, bottom conditions, reinforcement, concrete continuity, and bearing conditions are most easily checked during construction. Some of these observation methods include excavation around the shaft for relatively shallow inspection, down-hole inspection for end bearing conditions or rock sockets, and video camera devices for remote inspection. In rare circumstances, a drilled shaft can be extracted for inspection. Before concrete placement, the bottom of the shaft can also be probed by drilling or coring to determine if there are voids or soft zones in the material at the base of the shaft.The Drilled Shaft Inspector’s Manual focuses on traditional "topside" inspection for routine drilled shaft construction."

Jan 1, 2004

By Giovanni A. Bonita, Asher H. Peltz, Sean D. Johnson

This paper examines a complex earthwork project in the Washington DC metro area that had project delivery directly impacted by questionable instrumentation monitoring data. The case study summarizes the impacts to the project caused by questionable instrumentation data and reveals how the authors were able to utilize data to extract meaningful insights. The case study also demonstrates how clear data presentation became a key factor in maintaining stakeholder trust and facilitated progress of the project schedule. The case study highlights key points to collecting high quality instrumentation data, approaches to assess and improve value of the data collected, and techniques to reduce and interpret questionable data.

By X. Y. Hou

The design practice of several circular underground projects with large diameter is summarized. By taking the advantages of load-bearing of circular structure, a rational annular tensile bar support system and a new design method are proposed. Calculation for a car park shows that remarkable results are brought in by this design technique.

Jan 1, 2010

By Mohammad T. Izadi

Piles are, often, used for transferring load from the super structure through soft consolidating strata onto relatively stiff uncompressible soils. Downward movement of the soft soil strata develops negative skin friction and dragload around the pile shaft, with time. Traditionally the induced dragload is considered in determining the pile bearing capacity. On the other hand, field measurements on instrumented piles show that negative skin friction is reduced by the magnitude of applied live load. A method for calculating the pile bearing capacity, driven through soft consolidating strata is presented. In this method, two allowable load-bearing capacities are calculated for each pile, live load plus dead load and dead load. The proposed method, substantially, increases the allowable load bearing capacity of piles compared to calculated values by the traditional methods.

Jan 1, 2001

By M. Nomura

This paper describes the results and field measurements of two long-term observation tests and two short-term loading tests to confirm the effectiveness of NF piles in reducing negative skin friction. All the test piles were equipped with strain gauges, allowing measurement of the compressive axial forces in the piles. These test results prove that NF piles are effective in reducing the negative skin friction to an insignificant value. Some examples of the design procedures used in Hong Kong and Japan are also presented.

Jan 1, 2010

"After the non-destructive testing is completed, the data must be compiled, evaluated, and interpreted. During this process, the data may indicate that there is an anomaly warranting further investigation, which may eventually be determined to be a flaw or defect. The definitions of an anomaly, flaw, and defect can be described as follows (after Amir, 2002):Anomaly - Any irregular feature identified in the NDT graphic results. An anomaly may be due to the testing instrumentation (such as noise), to the means used to perform the test (e.g. access tube debonding in CSL) or to the shaft itself. It is the responsibility of the NDT practitioner to gather and analyze all relevant data and try to resolve every anomaly before it is declared a flaw or defect.Flaw - Any deviation from the planned shape, size and/or material of the shaft.Defect - A flaw that, because of either size or location, may detract from the shaft’s intended performance or durability. The geotechnical engineer and the structural engineer are jointly responsible to decide which flaw comprises a defect.This section describes the process of evaluating the data, determining if an anomaly exists, and if so, deciding whether the anomaly is actually a flaw or a defect. If the anomaly is determined to be a defect, its effect on the performance of the shaft must be evaluated, and if necessary, the can be re-engineered, repaired, or replaced."

Jan 1, 2004

By Rakam Lama Tamang, Michael J. Byle, Stephen Ernst

"For various reasons, dredging may become necessary in front of existing bulkhead walls, either for channel deepening or for environmental remediation of contaminated sediments. The removal of sediments at the base of bulkhead walls removes support for the toe of the wall that must be assessed. Evaluation of this impact can be problematic for aging bulkheads for which no design or construction records exist. This paper will address the steps that should be taken in investigation and analysis to assure proper assessment and means to address uncertainties and gaps in information. The steps include pre-investigation data review, field inspection, geotechnical and geophysical investigation tools, parametric analysis and design tools. Examples from several bulkhead assessment projects will be provided that include a variety of conditions and tools for application. The focus of the paper will be on the integration of technologies to assess bulkhead geometry, geotechnical properties and stability, structural safety and constructability issues with removal of support, and means of temporary and permanent stabilization for environmental applications.IntroductionBulkheads and quays have existed as long as there have been waterfront activities. Some of the earliest date back to 1200 B.C.E.(Raban, 1987), however in the United States few predate the eighteenth century. Most extant bulkhead structures, and all steel sheet pile bulkhead walls date from the early 20th century or later. These structures function to protect the shore from erosion, support landside activities, and serve as place to moor and offload vessels. Regardless of the age or usage of existing bulkheads, it is essential to assess and protect them if needed where removal of soils on the water side of the bulkheads is planned to dredging.Waterfront BulkheadsExisting bulkhead structures can be classified into two types: Cantilevered, and anchored. Cantilevered walls are completely supported by the soil on the water side, while anchored bulkheads are supported both by the soil on the water side and anchorage on the land side (Figure 1). Walls may be constructed of timber, steel, or concrete. Timber walls may be lagging with soldier piles, cribbing with soldier piles, or timber sheeted such as Wakefield walls (Figure 2). Steel bulkheads are most commonly constructed using sheet piling comprised of interlocking A or Z shapes, though some historic walls were constructed with flat sheets. Precast concrete sheet piling has also been used in construction of bulkhead walls. Anchorage may be provided by steel bars or tendons attached to deadmen, sheet piling, driven piles, or earth anchors."

Jan 1, 2017

By Lynn Crayne

We used Glyoxal as the hardener, at a final concentration of 10% by volume and therefore 20% by volume in the A-Component. They worked pretty well what we did was we shaved the joints on each of the pipes when we assembled them so they wouldn't rip the packers and then we greased the packers very well going in. We had to replace some but we have any getting stuck or didn't lose any pipes.

Feb 10, 2003

"What can we do in ground engineering to reduce damage to the environment, to repair historic pollution, to reduce our demand on basic resources and to reduce the carbon footprint of our industry? Some developments in geotechnical engineering are already heading in the right direction. These include reductions of ground pollution from grouting, improved dewatering procedures and advances in mix-in-place processes, ground improvement and jet grouting.There is increased interest in certain promising technologies (for example, drilled partial or full displacement piles), but this approach remains for the moment somewhat avant-garde. These piles require substantially greater power to install, and the overall sustainability balance for general application has yet to be shown to be in their favour. They are particularly suited to polluted sites where the problem of dealing with spoil would be costly and where, in the past, driven cast in-situ piles would have been employed. Drilled displacement piles offer some environmental benefit over driven piles in that they cause far less drawdown of potentially contaminated near-surface ground into sensitive, underlying aquifers.There is also great interest in various means of increasing the frictional capacity of bored piles, both conventional auger and continuous flight auger (CFA) piles, by threading or ribbing the soil/pile interface. The increase in adhesion capacity allows reduction in the pile dimensions necessary for a specific load. This obviously leads to less construction waste, but also to less permanent material consumption in the piles and also in the pile caps.The role of ground improvement remains significant for brown land sites and lower capacity foundations. Information technology (IT) has improved the quality assurance of stone column construction, for example. From the sustainability point of view, this is a good news method; here is no cement, no pollution and little obstruction to future redevelopment. We now need to introduce recycled crushed materials instead of natural aggregate as general practice and the technique’s green credentials will be really compelling."

Jan 1, 2009

By Eric Rehwoldt, Walt Rabe, Jesús Gómez, Tim Myers

"An expansion plan for Washington Dulles International Airport is currently underway to prepare for growth at this northern Virginia facility in the future. While Dulles currently serves more than 20 million passengers a year, when the Master Plan for the Airport is fulfilled, it will be capable of handling approximately 55 million passengers a year. The current Capital Construction Program underway at Dulles will take the Airport one step closer to its full potential.As planned, work includes a new Airport Traffic Control Tower, expansion to existing concourses, a fourth runway, additional parking, and other improvements. One of the most interesting features of this project is the construction of a two-track passenger train system (Automated People Mover, or APM) linking the main terminal and concourses, which will largely replace the Mobile Lounge transportation system, thus greatly reducing surface traffic. Construction of the APM system involves deep excavations along the tunnels and at the transfer stations. This poses special challenges because the settlement-sensitive terminal, original Airport Traffic Control Tower, and concourse buildings, as well as other facilities, exist near the proposed below-ground stations. The site is also underlain by a tight grid of underground utilities that include jet fuel, gas and central communication lines, in addition to more mundane electric, sewer and water mains.One of the most interesting features of this project was the extensive and skillful utilization of micropiles for support of existing structures adjacent to the excavations. Without the use of micropiles, the cost and difficulty of the excavations would likely have been much more. Several important lessons were learned about the use of micropiles, which advance that technology.Throughout the project site, bedrock was generally encountered at 25-ft depths or more. The rock consists of micaceous and highly calcareous siltstone rock. This rock is typical of the sedimentary component of the Culpeper Basin, a Triassic Age geologic feature extending from south central Virginia to western Maryland. The siltstone beds dip gently to the west at about 10 to 20 degrees. Joint planes typically dip 60 degrees to vertical. The rock underlies a sequence of fill materials and residual soils of varying thickness."

Jan 1, 2009

By W. G. K. Fleming

The codification of foundation design and construction is a subject of extensive discussion in Europe and all current code proposals are based on limit state partial factoring. For simplicity, it is claimed, simplified forms of Partial Factor use are presently being advocated but, if this is the direction which codes are to follow, then it is preferable in this age of computer technology that a true system should be adopted rather than a simplification. A philosophically satisfactory method can readily be found which can fulfilcurrent requirements and it is better that such a method should be adopted from the beginning rather than later to find it necessary to make important alterations and amendments.

Jan 1, 1996

By Barritt Lovelace

Collins Engineers has been researching and implementing the use of drones on Civil Engineering Projects since 2015. Applications include bridge inspection, asset management, mapping, construction site management and emergency response. Recently this technology was used to map and model construction sites with deep foundations to verify and quantify designs. The ability to collect and use large amounts of data is transforming our world. Drone hardware and software is being used to capture and digitally replicate assets, giving owners unprecedented ability to visualize and manage their projects. Our teams help owners collect and process drone data into deliverables to be analyzed, annotated, stored, and shared. The use of drones can transform the way projects are managed and can improve project workflows. Data collected with drones can be processed into a digital twin of any project site or asset. This digital twin provides owners with a three-dimensional geometrically and geospatially accurate model. These models can be annotated and tagged with information that can be stored and shared locally or on cloud-based platforms. The data can be exported and used in a wide variety of CAD and GIS platforms. Goals When considering the use of UAS for several items need to be considered when establishing project goals. Safety Drones can be used to reduce job site safety risks in two ways. The first is that use of the drone can remove personnel from harm’s way. Surveyors and other project staff will traditionally walk the site to collect survey and other site information. These efforts can be replaced with the use of a drone eliminating much of the need for personnel to be on the job site itself which improves safety. The other way safety can be improved is that a digital model of a job site can be created on a daily or weekly basis that can be quickly analyzed for safety hazards. This analysis could be done remotely by safety officers to identify job site hazards which can then be corrected before injuries happen. Improved Deliverables Perhaps the most important reason to incorporate drones into project workflows it the ability to improve the project deliverables. Drones have the ability to quickly collect large amounts of high quality data which can be processed into orthomosaics, point clouds and 3D models that give engineers and project managers the information they need to make better decisions on design or project management.

Jan 1, 2019

By R. Paul De Bruyn

A. Crane Check List -- Make -- Model -- Year of Manufacture -- Where is load chart? Is it for this crane? -- Boom style and length -- Boom tip drawing (sketch) for fixed lead connection. Has the crane manufacturer been consulted on the point of attachment? -- How many drums; diameter and length of wire rope. -- Is the single part line pull enough to lift pile or hammer on single part line? -- What is the effective weight of the whole driving system - leads, pile, hammer, etc? -- Are there any auxilliary hydraulic systems? Are the line pulls on these adequate to lift the pile or hammer? -- What is the anticipated working radius? Will the spotter collapse to that length? -- Nature of foundation under crane - barge, marsh, unstable sand, etc. -- Does the crane meet OSAH and state regulations -current certification. Note - the operator is responsible for compliance with regulations. -- Is there any extra weight added to counterweight by compressors or hydraulic systems? What does crane manufacturer say? Consult factory before adding.

Jan 1, 1990