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By R. J. Folic

Investigations of the vibrations of a pile in soil are performed on a dynamic model in the form of a prismatic bar of finite axial and flexural stifnesses with a discrete mass at its free end representing the cap. The soil is represented by a system of springs of constant and variable stiffnesses. Oscillation differential equations are derived by means of the Hamiltonian principle for non-conservative systems. The problem is reduced to a coupled system of two non-linear partial differential equations with corresponding initial-boundary conditions. Frequency equations of longitudinal and lateral linearized equations are formed. The paper determines natural frequenc­ies and oscillation modes. It separately examines longitudinal vibrations excitated by a hermonic force acting upon the pile cap, and lateral vibrations excitated by an impulse acting upon the cap. The results of the numerical processing are presented in respective diagrams in dimensionless form.

Jan 1, 2010

By Eric C. Halpin

"1. Introduction and Backgrounda. In its fundamental form, risk is simply the likelihood of an adverse impact. Expanding on this theme, the Corps of Engineers has broadly defined risk associated with infrastructure as a factor of three distinct elements: a probabilistic assessment of a hazard such as a flood or earthquake; a probabilistic assessment of how the infrastructure performs in the face of this hazard; and a measure of the likely consequences – loss of life, economic damage, environmental impacts – associated with the resulting inundation scenarios.b. The lessons and observations described herein relate to the Corps of Engineers experiences in implementing risk concepts for infrastructure management during the period 2005 through 2013. The Corps of Engineers is a large, decentrally operated and centrally led federal agency that plans, designs, constructs, operates, maintains, and/or manages a portfolio of over 3,000 built dam and levee systems within the United States. The infrastructure in this portfolio is 55 years old on average, and although much of the structures provide for flood risk management benefits, many of the dams deliver multi-purpose benefits. Scale matters – where scale and uncertainty are large, risk concepts provide great opportunity and arrangement for application.c. The amount of organizational change that is demanded for the implementation of risk concepts is considerable and should not be under estimated, but need not be feared if the path others have taken is considered. This paper is, in many ways, an opportunity to step back from the last seven years of implementing risk informed management, check our own azimuth and maturation, and share the purpose and energy behind our own continuing actions. Hopefully, this azimuth check is also beneficial to those that are either considering the use of risk or are in the process of implementing risk concepts.d. Success at managing the massive change related to incorporation of risk concepts will directly affect success of the infrastructure program. The three key organizational elements to consider –human systems such as governance and competencies; policies that outline the who, when, and why of decisions and management; and the processes and technology that outline how work is to be performed - are changed fundamentally. From senior leaders to project team members and all of the people in between, there is a need to discuss, confront, and vet the change and the role people and organizations have in the process. For the Corps of Engineers, with a history of over two centuries, deeply embedded beliefs about infrastructure aren’t transformed over night - the change process is decadal in scope. Given our self imposed “project execution” mantra and corporate objective, risk seemed threatening at first to the cost and schedule of delivering infrastructure projects. In reality, risk concepts have been responsible for savings and cost avoidance of nearly $6 billion over the last three years alone while at the same time justifying increased investment by several fold for the highest risk needs."

Jan 1, 2014

By Luo Yang

A one-dimensional wave equation based algorithm for estimation of shaft and toe resistance of driven piles using High Strain Testing (HST) data is presented. The pile is represented by a uniform elastic bar, while the soil around the pile is assumed as a homogenized isotropic medium, and Smith model is adopted to represent soil-pile interaction in the wave equation analysis. In most cases, the displacement of pile particles along pile shaft is greater than recoverable soil deformation (i.e., soil quake in Smith model). Therefore, static shaft resistance could be reasonably assumed to be totally mobilized during pile driving. Smith damping factor is used to account for combined dynamic and rate effect. Force and velocity time histories measured at the pile head are used as input boundary conditions in an analytical solution of the one-dimensional wave equation. As a result, two unknown parameters, static shaft resistance and Smith damping factor, can be incorporated into the one-dimensional wave equation and determined analytically for the time duration prior to the first downward wave reaching the pile toe. Then, soil resistance and Smith damping factor at pile toe can be further determined. The advantage of the proposed analysis technique is that the Smith damping factor and the static soil resistance can be directly determined based on the closed-form solution of the one-dimensional wave equation, which is computationally efficient. Numerical examples are given to illustrate the use of the proposed method to determine the pertinent Smith model constants and the static resistances.

Jan 1, 2006

? Hollow Stem Auger ? Drill Bits ? Leads/Torque Arm ? Hydraulic Gearbox ? Hydraulic Power Unit ? Grout Pump ? Crawler Crane

Jan 1, 2000

By Rick Ellman, Ian Chaney

"The Hampton Roads area encompassing the Norfolk, Virginia Beach and Newport News metropolitan region experiences some of the worst traffic congestion in Virginia. With continued growth of the ports and increasing demand, the Virginia Department of Transportation (VDOT) initiated the Downtown Tunnel/Midtown Tunnel/MLK Expressway Project, a complex undertaking critical to addressing the Hampton Roads area’s transportation needs. The project is a $2.1 billion Design/Build/Finance/Operate (DBFO) endeavor most notably involving the construction of a new two-lane vehicular tunnel utilizing the Immersed Tube Tunnel (ITT) method. The tunnel will pass under the Elizabeth River parallel to the existing Midtown Tunnel between Norfolk and Portsmouth, Va. It will be the largest design-build project constructed in the history of the Hampton Roads District.The New Midtown Tunnel will extend approximately 6,450 ft (1,966 m) along the north side of the existing tunnel where it ties into the existing Midtown Tunnel approaches in Norfolk and Portsmouth. It is being installed in a pre-excavated trench of which approximately 2,250 ft (686 m) required bracing on the Portsmouth side and approximately 1,000 ft (305 m) required bracing on the Norfolk side. The remaining 3,200 ft (975 m) of trench excavation was open cut dredging with laid back side slopes, optimized to reduce dredging, disposal and backfill quantities while also reducing the risk to the existing tunnel. The braced excavation portions of the tunnel alignment were divided into distinct segments which include: Portsmouth Approach Boat Section, Portsmouth Approach Cut-and-Cover Section, Portsmouth Dredge Section, Norfolk Dredge Section, Norfolk Approach Cut-and- Cover Section and the Norfolk Approach Boat Section. All “approach” excavations were performed in the dry and all “dredge” excavations were performed in the wet. Eleven ITT segments are being fabricated in the Sparrows Point Dry Dock facility in Baltimore, Md., and each 14,000 ton (12,700 tonne) segment is being towed approximately 220 mi (354 km) to the site. The ITT segments will extend under the Elizabeth River, with the deepest crossing 90 ft (27 m) at the Federal Navigation Channel. Once beyond the channel limits the ITT rises at an approximate 4.5% slope. Controlled screeding and element lowering operations will be performed primarily from floating barges."

Jan 1, 2014

By Joanna Bzówka

Nowadays, there are some new requirements for the supermarket floors. The floors are loaded by high point- and moving-loads. In spite of this fact, it is necessary to ensure the stiffness of the floor and the stiffness of its support. When pile foundations are designed in the case of weak soil, the piles are recommended under the foundations of the supermarket and also under the floor layers. The example of foundation of a typical supermarket located on long­standing municipal dumping ground is presented. Indirect foundation - CFA piles, 0.5 m in diameter and 4.5 to 20.0 m long, was de­signed. Fifteen trial loading tests were carried out.

Jan 1, 2006

By J. L. Goen

The Saint Joseph Hospital of Bellingham is located on a site underlain by glacial outwash. The construction of a five-story tower addition above an existing two-story wing was supported by five large trusses that impose a 1600 kips (7117 kN) column load on five pile caps in the courtyard of the hospital and on the new pile caps inside the existing MRI laboratory. The exterior columns of the trusses and the new parking garage addition were supported on conventional auger cast piles installed with conventional equipment. Helical Pulldown® micropiles were selected for use in the courtyard and the MRI laboratory because lightweight installation equipment (maximum unit weight of 7.5 kips (33.3 kN)) had to be used and it was required that no spoils be produced. The installation equipment was lifted into the courtyard by the jobsite crane. Sixty Helical Pulldown micropiles were installed for the pile caps in the courtyard. The pile caps inside the hospital were supported on 240 Helical Pulldown micropiles. Initial compression test indicated an allowable load for the micropiles to be 55 kips (244 kN). However, retest at a later date resulted in an increased allowed design load to be 85 kips (378kN) reducing the number of micropiles required by more than fifteen percent.

Jan 1, 2004

By Bin Zhang

Drilled shafts are a popular type of foundation for transportation applications. They feature the advantages of providing high bearing capacity and generating low construction noise. Advancements in construction technology make it possible to construct drilled shaft with large diameters. In some transportation projects, the full structural loads are carried by a single large diameter drilled shaft; therefore accurately determining the bearing capacity of drilled shafts has important practical and safety implications. The increase of drilled shaft diameter combined with the structure properties of the surrounding soil play in an important role in their bearing capacity. The conventional methods for bearing capacity determination, which mostly come from experience with small diameter drilled shafts, may not work satisfactorily. This paper studies the influence of diameter on the bearing capacity of laterally loaded drilled shafts. Numerical simulations are conducted to investigate the effects of pile diameter on the lateral bearing capacity, especially the influence of shaft diameter and its structural contributions.

Jan 1, 2007

By Arash Khosravifar

One of our research thrusts at Portland State University (PSU) centers on developing design guidelines for pile foundations in liquefiable, laterally spreading grounds. This research has been primarily sponsored by the DFI Committee Project Fund (CPF) program through four awards, totaling nearly $240,000 in financial support. DFI contributed half of this financial support, while the other half was contributed in-kind by PSU and DFI Project Advisory Board members. Leveraging the CPF funds, we secured an additional $550,000 in financial support from the National Science. Foundation (NSF), which has enabled our research group to continue exploring this topic and contributing to the broader engineering community's understanding of the behavior of pile foundations in liquefiable soils. The CPF funds have fostered collaborations with practitioners and researchers beyond PSU. Notable examples include collaborative research involving data from five large-scale centrifuge tests on pile-supported wharves by Steve Dickenson, Ph.D., New Albion Geotechnical; Nason McCullough, Ph.D., Jacobs Engineering and Scott Schlechter, Geotechnical Resources, as well as 1-g shake table tests of bridge pile shafts conducted by Professors Ahmed Elgamal, Ph.D., and Ahmed Ebeido, Ph.D., of the University of California, San Diego. In addition to these collaborations, our research has benefited from industry-university partnerships formed through the involvement of DFI Project Advisory Board members. Their support and feedback ensure that our research products are practical and imple- mentable in real-world projects. The impact of the CPF funds extends to supporting graduate students' theses, which were the basis for 17 technical publications. Some of these publications are expected to have a significant impact on the industry. For instance, our 2018 DFI Journal paper, co-authored by former master's student Jonathan Nasr, cur- rently with the Army Corps of Engineers, has been cited in the 2022 British Columbia Supplement to Canadian Highway Bridge Design Code S6:19. A noteworthy product of our study is a step-by-step design procedure for pile- supported wharf structures subjected to the combined effects of lateral spreading and inertial loads, outlined in a 2022 American Society of Civil Engineers' (ASCE) Journal of Geotechnical and Geo- environmental Engineering paper co- authored by former doctoral student Milad Souri, Ph.D., PE, Geotechnical Resources.

Nov 1, 2023

By S. Kanai

Nodular piles is to be piles provided with several nodular projections along the pile shaft, as shown in Fig. 1. Nodular piles are usually installed through either driving method with hammer or preboring method. This paper presents that the bearing capacity installed through each method is considerably higher than that of cylindrical pile without nodules. This paper also proposes the statistically analyzed unique formulae of the bearing capacity of nodular piles.

Jan 1, 1989

By Tianfei Liao

Extensive site investigations revealed that abandoned shallow mine workings exist under a site planned for construction of a major new facility. Since the mine voids were susceptible to collapse, they were stabilized by grouting. After completion of the mine remediation, three types of deep foundations (micro-piles, auger-cast piles, and drilled piers) were considered for this site. Micro-piles spread the load via the bond between the pile and the bedrock. Without significant length socketed in rock, the axial load of auger-cast piles and drilled piers has to be concentrated on end bearing. Although spreading the load is preferable in this environment, economic consideration dictated the choice of drilled piers for construction.

Jan 1, 2009

By Richard Brink, Eric M. Klein, Kenneth B. Andromalos

"A portion of the roof for a 129 x 144-inch, nearly 100-year-old sewer outfall in the City of Baltimore had deteriorated to the point that it resulted in the development of a large sinkhole in a residential neighborhood. A subsequent video inspection of the sewer outfall indicated that there was a hole in the sewer outfall, and it would need to be repaired . After initial backfilling of the sinkhole and repairs to the water service lines, a conventional wood shoring system was used to support the excavation and expose the Main Outfall Sewer to inspect and repair it. This excavation was unsuccessful because of loose sandy soils and high groundwater conditions. An innovative use of a steel reinforced jet grout excavation support system was ultimately used to underpin an adjacent 20-inch water main and other nearby utilities, and provide access to the top of the Main Outfall Sewer some 22 feet below the street surface to facilitate inspection and repair of the sewer. This excavation support system was also successfully utilized in the final repair of the sewer roof by serving as a buttress for the new roof system.1.0 IntroductionThe project site is located in a residential neighborhood with brick masonry row houses situated on the south side of Chase Street and a brick masonry church on the north side of the street. Figure 1 illustrates the location of the site. The City right of way is 65 feet wide, and the street is 40 feet curb to curb. The centerline of the Main Outfall Sewer runs parallel to and a few feet south from the centerline of the street. Other utilities running parallel to the street include a cast iron 20-inch water line built about 1910, a 24-inch terra cotta storm drain, a 6-inch terra cotta sanitary sewer, a 4-inch cast iron gas line and a 40-inch electrical duct. Cross utilities included a 4-inch gas line and several smaller water and gas service lines to the church and row houses. One gas line that was not shown in the City's GIS database was exposed during the excavation."

Jan 1, 2005

By Jean Balech

This paper presents some results of dynamic loading tests performed on concrete piles driven in soft clay formation. The load transfer mechanism, measured in the dynamic increasing energy test (DIET), under blows of growing energy, is described in terms of mobilized normal forces diagrams and unitary local friction and displacements. It was observed that the lateral skin friction grows up to a maximum, in the soft clay layer and, gradually diminishes to a residual value when the system presents the maximum mobilized resistance. It may be concluded that the rupture load is not equal to the maximum mobilized point resistance plus the maximum mobilized local friction as suggested by most of static bearing capacity formulae.

Jan 1, 2002

By Padmavathi V. Sagi

In this paper, effect of cyclic loading on the behavior of a long, flexible, unrestrained vertical pile loaded laterally in soft clay is examined. For cyclic loading, the analysis is carried out using a new method for the construction of p-y curves and for static loading conditions, p-y curves proposed by Dewaikar and Poonam (2005) are used. An iterative analysis is employed with secant modulus approach using a matrix method known as moment area method developed by Sawant et al. (1994). For pile top deflection of 20% of pile diameter, the load values are computed for both static and cyclic conditions. The comparison of results with the field test results reported by Matlock (1970) shows a good agreement. A parametric study is further carried out to examine the effect of load eccentricity, pile embedment length, diameter and the number of cycles on the pile response. The results of this study are discussed in the paper.

Jan 1, 2006

By Viswanadham B. V. S., Babu K. V

Many refineries are in the process of revamping and expanding their existing facilities. Most of the refineries are located in coastal areas due to ease of transportation and storage of crude oil. Considering the criticality of structures as well as prevailing soil conditions, most of the structures are supported on pile foundations. In depth review of sub-surface investigations data followed by liquefaction assessment of the site, it is noticed that site is prone to liquefaction during the seismic event. Among various techniques, driven cast-in-situ piles were selected to mitigate liquefaction. Static cone penetration tests were conducted during the pre and post installation of driven cast-in-situ piles at identified locations. Analysis of cone penetration test data shows that considerable ground improvement has been achieved post-installation of driven cast-in-situ piles.

Sep 1, 2022

By N. V. Nayak

Konkan Railway Project is one of the most ambitious railway construction projects in India, involving construction of a 760.km long, Broad Gauge (1676 mm), single track railway line, connecting Roha in Maharashtra State with Mangalore in Kamataka State. The railway line travels along the Western Coast of Indian subcontinent, through states of Maharashtra (382 km), Goa (105 km) and Karnataka (273 km) (Fig.1). The project alignment traverses through one of the most formidable terrains ever encountered, in the history of railway construction in India. In the State of Goa only, railway alignment is crossing 6 major rivers Terekhol, Chapora, Mandovi, Zuari, Sal and Talpona. Zuari Railway Bridge (1305.6 m), Mandovi Railway Bridges (I and II) (1182.7 m) rank as 2nd and 3rd long bridges, (first longest bridge being Sharavati Bridge (2.2 km} at Honavar) which have been constructed on Konkan Railway. All these three bridges have been constructed by M/s.Asia Foundations and Constructions Ltd. (AFCONS). This paper presents, case history of construction of pile/caisson foundations for Zuari and Mandovi Bridges.

Jan 1, 1996

By David E. Albus, Bidjan Ghahreman

A single-family home constructed on the side of a slope in Los Angeles, CA, was subjected to lateral forces due to soil slope creep on the pile foundation supporting the home. Impacts to the property included cracking and separations in the street, retaining walls, exterior concrete flatwork, and decorative concrete features in the rear yard area. The home was supported by concrete piles that penetrated the surficial soil mantle and were embedded in underlying bedrock. However, the home exhibited minor distress that suggested even the home was being affected by soil creep. Selected points on the home were monitored with an optical survey method and manometer over a period of two years to assess if the home was undergoing vertical or lateral movement. Monitoring data indicated the home was in fact moving down slope in a manner consistent with slope creep. As a result, the authors were concerned that continued movement due to slope creep could result in over-stressing of the piles that support the home and ultimately lead to failure of the foundation system. An evaluation was then undertaken to evaluate the behavior of the foundation system due to forces from slope creep. Research was performed during the course of evaluating the conditions to consider various approaches to modeling pile behavior of the piles supporting the home. Some research has been performed to field measure creep displacement of soils and rock in slopes. These previous works have found a diverse behavior of the soil displacement with depth (velocity profile) indicating the process is very complex. An example of various velocity profiles measured in field experiments is depicted in Figure 1. Other research focused on theoretical models of velocity profiles and exhibited similarities to some of the field measured cases.

Jan 1, 2018

"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 A. Verghese Chummar

The paper presents a field study where the effect of negative drag caused the failure of a pile foundation system. Utilising the field observations the probable negative drag that acted on the piles is worked which gives an insight into the effect of negative drag on deep foundations.

Jan 1, 1996

By Paul J. Axtell

Two new railroad bridges in Kansas City, Missouri are founded on drilled shafts embedded into the soil and underlying shale. The uncertainty arising from the non-homogeneous, anisotropic nature of most shales, and the variability of shales across the U.S., makes it a difficult material to assign appropriate design properties. As was the case on this project, the uncertainty of foundation performance in shale can lead to overly conservative designs, particularly with drilled shaft foundations. An extensive Statnamic axial testing program was performed to verify that the load-settlement behavior of the drilled shafts would be acceptable for the intended railroad traffic. Axial Statnamic testing was applied in three increasing cycles of 927 kips, 1007 kips, and 3177 kips, respectively. The maximum movements recorded at the shaft head during each of the loadings were 0.052 inches, 0.062 inches, and 0.257 inches, respectively. The loads applied in each of the respective Statnamic tests were not sufficient to reach the capacity of the shaft; so direct comparison of measured and calculated capacities is not possible. However, evaluation of the estimated design capacity can be accomplished based on results from the Statnamic testing program by utilizing normalized load transfer relations presented by O?Neill and Reese (1999). Such comparisons necessarily require extrapolation of the data measured in the Statnamic tests following typical load-displacement response. Results indicate the Kulhawy and Phoon (1993) method for estimating side resistance in Pleasanton shale rock sockets, assuming a smooth socket, appears to agree well with observed behavior during Statnamic testing. Accordingly, the O?Neill and Reese (1999) method for estimating the toe resistance in intermediate geomaterials, assuming cohesive rock with Rock Quality Designation (RQD) between 70 and 100, appears to agree well with observed behavior during Statnamic testing. Finally, based on Statnamic testing at varying load magnitudes and normalized curves developed by O?Neill and Reese (1999), the contribution of side resistance to the capacity of a deep foundation can be determined assuming no load is transferred to the base of the foundation during lower magnitude testing. Furthermore, higher magnitude testing can provide a means to evaluate the accuracy of design end bearing calculations.

Jan 1, 2006