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By Venugopal Bonani, Kumaran M., Thomas John

Liquid storage tanks are usually located in nearshore or coastal regions with soil profiles containing thick layers of compressible soils. These storage tanks are usually of large diameter up to 90m and carry high loads, and the tanks are supported by heavy deep foundations such as piles. These structures are subjected to huge lateral loads due to wind and earthquake, and any damage to storage tanks with highly inflammable liquids leads to disastrous condition. So, it is important that the top layer of soil (up to the fixity depth) should be strong enough to provide the required lateral load capacity to the pile. In a project for constructing LNG terminal in Odisha containing 2nos of 89m diameter LNG storage tanks supported with pile foundation located near to coastal region, for improving the lateral capacity of existing soil, the top 3m was replaced with compacted engineered fill (GSB). The site was a filled-up area with dredged soil from seabed, the top 5m-10m were soft to medium stiff clay with SPT N less than 10. The lateral design load on pile was 534kN under free head condition. Actual lateral capacity for the strata was around 200kN under free head condition which was less than required capacity as per structural requirements. Therefore, for improving the lateral capacity of pile the top 3m soil is replaced with well compacted engineered fill (GSB) in layers of 150mm and the capacity is proved by conducting initial and routine lateral load tests. This paper describes the properties of the engineered fill used and how the lateral load capacity of pile was improved to meet the design requirement.

Sep 1, 2022

By Gisele R. Passalacqua, Taylor Malangone, Subhash Mahali

New York City is a busy metropolis with 8 million people. New York has the largest public transportation system with 6 million riders a day throughout the subway system. Keeping this infrastructure in service is vital to the overall economy of the region. Hurricane Sandy proved to have a devastating impact on infrastructure in Metropolitan New York. New York City Transit is on the forefront to provide resiliency and maintain its facilities with the use of flood protection systems. This paper presents flood protection structures utilized at Hammels Wye substation site in Far Rockaway, Queens, New York. The site is in close proximity and surrounded by water. The subsurface conditions consist of loose silts overlain by medium dense glacial sand. The high groundwater level combined with limited access to the site presented challenges. A flood protection system consisting of flood walls was recommended for this site. In certain areas the flood walls consisted of retaining walls supported on micropiles. For other areas, the flood walls consisted of steel sheet piles with jet grout columns to reduce seepage below the walls. The effect of driving sheet piles with vibratory hammers on nearby existing structures is always a concern. Recently, hydraulic hammers with variable moment/frequency are being considered as a mean to reduce vibration effects during driving. In this project, an instrumentation testing program was performed to measure peak particle velocity during sheet pile driving utilizing the variable moment vibratory hammer. Plots of peak particle velocity versus frequency were generated. This paper will present the design aspects of the flood walls and construction challenges during installation. This will prove beneficial to engineers in both design and construction fields.

Sep 8, 2021

By Karen C. Armfield, Gisele R. Passalacqua, Joanna Smith

New York City is an urban environment with a history spanning over 200 years. The coastline of New York has changed over the years. In the East River, old bulkhead and remnant of relieving platforms together with variable bedrock elevations pose challenges in the design and construction of deep foundations. This paper presents a Case History of high capacity deep foundations along the Franklin D. Roosevelt (FDR) Drive on the Upper East Side in New York City. The project consists of a ramp that overpasses the FDR Drive allowing heavy trucks to access the Marine Transfer Station (MTS) facility built over the East River. Large diameter drilled shafts and mini-piles socketed to bedrock were designed and constructed. Remnant of old bulkhead was encountered at the site and a Ground Penetrating Radar (GPR) investigation was completed during the subsurface investigation phase of the design. This paper discusses details of the subsurface investigation program and design methodology of the high capacity drilled shafts and mini-piles. It also describes construction methods and results of Osterberg Load tests documenting the field values of skin friction through the rock socket. Other construction challenges include construction and drilling rock sockets for drilled shafts over sloping bedrock. 1. INTRODUCTION New York City is a renowned urban city that always calls for the most delicate, yet complex, and robust superstructures and most importantly substructure designs. The historic preservation of this large 200 years old city of 319 square miles is ever changing. Shorelines are often extended to accommodate new infrastructure and very often many miscellaneous structures are discovered below the ground surface. The East 91st Street Ramp was constructed to provide access to the East 91st Street Marine Transfer Station over FDR Drive and York Avenue. Another alternative ramp will be relocated to the South Bound (SD) of the FDR Drive at 92nd Street. A subsurface exploration program was completed in accordance with the New York City Department of Design and Construction (NYCDDC) general requirements, Section 4.5, to perform subsurface investigation along the FDR Drive in Manhattan, New York.

Jan 1, 2019

By Douglas R. Hardin, Stanley L. Worst, Joanna Mason

A challenging earth retention project presented itself in Washington, DC in the backyard of the historic House of the Temple (The Scottish Rite of Freemasonry, Supreme Council 33°). Located at 15th St NW and S St NW, a forty-foot-deep underground basement was to be installed adjacent to the existing Temple, a historic Carriage House structure dating back to the 1800’s and across a narrow alley from a four-story brick apartment building. The unique geology of the site included typical urban fill overlying a mixture of loose alluvial soils underlaid by dense marine deposits of the Potomac Formation. The clay, sand and gravel of the Potomac included nested boulders up to three feet in diameter. Design of the earth retention system accounted for ground conditions, installation methods and estimated movement of the system and adjacent structures. Anticipated ground water and unanticipated water from leaky sewers also proved obstacles to overcome during construction. Soldier beams were installed using a variable momentvibratory hammer to minimize disturbance to the historic and sensitive structures. Monitoring of the existing structures included both seismograph and optical targets during installation of soldier beams and as the excavation progressed. Micropiles drilled into the Potomac Formation were a part of the permanent foundation for the new structure. This local case history will delve into the details of the successful design, installation, and performance of an earth retention system and micropiles in a historic and highly congested urban environment.

Oct 1, 2022

By P. K. Ray, Sudip Kumar Koley, Sainath M. Reddy, Devulapalli L. S Rasagna

Bangalore Metro Rail Project- phase II is one of the technological challenging project, particularly construction of underground metro rail system. The Bengaluru city is very congested area and connecting metro rail system with existing transportation networks is equally challenging. In this phase-II, the Underground metro is being constructed by blasting hard rock formation and supporting the shear zone. Most of the subsurface rock formations comprise of granitic Gneissic formations are of Precambrian age and shear zones that includes friable a thin weathered rock formation. With such subsurface geological conditions, , the anticipated construction challenges include : A) deep excavation of hard rock mass under old and sensitive structures and buildings, by controlled blasting; B) variation in the rock grade from grade I to grade V; C) weak rock mass at shear zone resulted in planar failure beneath the retaining wall; D) water seepage along shear planes; E) selection of a suitable method to conducted blasting near high voltage electrical machinery or power cables. This paper describes the methods adopted to mitigate these technological challenges and to meet stringent environmental compliances. These includes study and application of various geological, geotechnical parameters to develop a proper line drilling and controlled blasting techniques to minimize the ground vibrations and controlling the rock fragmentation and to optimize the equipment performance in terms of productivity and time schedules. The “Phase 2” software of “Rocscience” has been used and Regression analysis has been carried out by using MCD (Maximum Charge per Delay) and PPV (Peak Particle Velocity) to estimate with FOS (Factor of safety) for sensitive places such as nearby high rise buildings and electrical transformers.re.

Sep 1, 2022

By Steven D. Scherer

The highest earthquake risk in the United States east of the Rockies is along the New Madrid Fault System, which extends for 193 km (120 miles) through the Central Mississippi Valley from northeastern Arkansas, through southwestern Missouri, western Tennessee and western Kentucky to southern Illinois. Historically, this fault has generated some of the most powerful earthquakes in U.S. history, notably three Magnitude 8 events in 1811. Apart from the West Coast, this region experiences more earthquakes than anywhere else in the United States, with more than 200 events recorded along the fault annually. These events are typically of much lower magnitude than those experienced in California. Most are too small to be felt. However, should a significant event occur, damage can be expected to be widespread because of the underlying geology. In recent years, earthquake preparedness and seismic upgrade of vulnerable structures has become a focus for a number of State Departments of Transportation, including those in Illinois and Missouri where there is a potential for future damage. This paper presents three case histories illustrating three different techniques used to retrofit interstate highway bridge foundations bearing on potentially liquefiable soils. Friction minipiles were installed at the approach span of the I-57 bridge crossing the Mississippi River near Cairo, Illinois to provide additional support to the pile caps in the event of liquefaction of the underlying sands during a seismic event. In St Louis, Missouri, rock-socketed minipiles were installed to increase the capacity of drilled shaft foundations supporting a section of Interstate 64. In Mounds, Illinois, compaction grouting was used to densify loose sand deposits beneath a pile-supported interstate bridge on I-57.

Jan 1, 2001

By Bora Okumusoglu, Devon K. V. Mothersille

"AnchorTest is an innovative software package, specifically developed for tablets, that permits ground anchor test data assessment and management in real time. The solution has two components: a front-end tablet app runs on the Apple iPad platform, and a back-end Cloudbased system running on Amazon Web Services with an online cross-platform website, which can be accessed from any PC, tablet or even mobile smartphone. This tool provides full data analysis and data management capabilities and portability to create greater efficiency in the anchor testing process. AnchorTest is programmed to accommodate the major international anchor testing codes and incorporates an intuitive user interface, which is revolutionary compared to conventional engineering software designs. The use of this tool creates an environment where the testing of ground anchors has effectively become a paperless exercise with greater efficiency and access to instantaneous feedback on the performance of anchors in relation to established acceptance criteria.Historically, project personnel record and analyze the results from anchor load tests using spreadsheets and a laptop computer and/or on predesigned paperbased test sheets (usually as a backup of the testing). In addition, the processing of the test results is not typically performed in real time as the testing progresses — the calculations and analysis are performed either afterward while still on site (if a field office is available) or after returning to the office. Undoubtedly, on larger projects containing numerous anchors where multiple anchor tests may be performed at the same time, processing, analyzing and accepting the load test data and results can be especially time consuming, which could cause delays to the construction schedule.DevelopmentThe need for a more automated and digitized approach to record, process and analyze the data from anchor load tests was highlighted at a deep basement project for a mixed-use development complex in Moscow, Russia. The diaphragm wall supporting the structure was approximately 1,970 ft (600 m) in perimeter length and about 148 ft (45 m) deep, with an excavated depth of about 82 ft (25 m), which required six levels of single bore multiple anchors (SBMAs). This project provided a challenge to recording, processing and signing off on the data generated from some 3,600 3-unit SBMAs. More specifically, for this project, three hydraulically synchronized stressing jacks were used to stress and proof test each 3-unit SBMA, which resulted in nearly 10,800 data plots of the load-extension tests being generated. This project served as the main impetus in the conceptual design and optimization of AnchorTest."

Jan 1, 2017

By Marcus Daubner

This paper explains how BAUER Spezialtiefbau GmbH uses digital methods on projects - starting from work preparation to completion of works. More precisely, the advantages of BIM-based planning during work preparation and the automated and structured data management - both machine production data and the manually recorded quality-relevant reports - during execution phase are displayed. In this context, the benefit of the digital twin to optimize processes, to reduce defect costs, for a more effective reporting sys-tem, and the further usage of as-built information in the BIM or GIS process is described.

Sep 1, 2022

By Paul Pedini

The challenge of Contract C19E1 of Boston's Central Artery Project called for the construction of two roadways under the commuter rail yard at North Station. Two options were offered for the method of their construction: Slurry Wall Roof-First or Soft Ground Tunneling. The instability of the indigenous soils seemed to rule out the use of tunneling, so the slurry wall method was chosen. However, these soils were incapable of holding up during slurry trench excavation. After many episodes of ground loss on early panel excavations, Modem Continental Construction suggested a method of trench wall stabilization. The Contractor (MCC) both suggested wall stabilization method and requested that the owner participate in the funding for the effort. The Project and the Contractor were able to agree on a solution which resulted in collapse-free excavation...and found an innovative way to fund the solution.

Jan 1, 2002

By Muhannad T. Suleiman

The design of deep foundations supporting heavy buildings, bridges, transmission lines, and highway structures, is governed by lateral loads in many cases. However, due to the use of empirical or semiempirical approaches to develop the soil force-displacement relationships (i.e., p-y curves), a wide range of recommendations are presented in the literature. Recent efforts by the author and co-workers enabled simultaneous direct measurements of soil-pile interaction pressure and lateral movement along the pile length, resulting in p-y curves based on direct measurement. Advanced sensors including sheet pressure sensors and shape acceleration arrays were used in these experiments. The experiments were conducted at the Soil-Structure Interaction (SSI) facility funded by the Major Research Instrumentation Program at the National Science Foundation. This paper focuses on the SSI of single laterally loaded piles. The test pile was 101.6 mm in diameter and 1.42 m long, which were installed in well-graded loose sand. This paper provides a summary of the installation and testing procedures, soil properties, pile instrumentation, measured lateral load-displacement response, strain profile along the pile length, lateral movement along the pile length and the pressures measured at the soil-pile interface. Furthermore, the paper presents measured p-y curves compared to estimated p-y curves using empirical methods available in the literature.

Jan 1, 2011

By Denis Huber

The technical assessment of the final works on the "Stéphany Palace" project at Menton in France's Alpes-Maritimes region shows the importance of daily project monitoring based on the observation method recommended by the European standard Eurocode 7 which applies to Foundations and Geotechnical Engineering. Excavation operations to a depth of 10 m near the France-Italy railway track and adjacent buildings required precise observation of land deformations, regular piezometric monitoring as well as special design arrangements. Temporary active tie-rods were thus placed in phases in order to control deformations in the retaining structures resulting from excavation operations. The Menton region, terminating the Alpine arc of mountains, naturally required the consideration of seismic forces in phase in the lower floors of the building, directly linked to the buried walls. These calculations were carried out in accordance with the PS69/92 rules, calling for an increase in dynamic thrust under the effect of gravity field rotation.

Jan 1, 2002

By Andrew Budek

"Analytical and experimental work has shown that achieving the full inelastic lateral capacity of a pile may require the formation of a plastic hinge below ground level, in the pile shaft. The confining action of soil about the pile shaft was further been shown to greatly enhance the ductility capacity of the pile. An experimental program was therefore undertaken to build in the effect of external confinement through the addition of a GFRP jacket to the subgrade plastic hinge region. Two piles were thus modified, and compared to an unjacketed pile in a test rig which simulated a subgrade moment pattern and soil confinement. The ductility achieved by the jacketed piles was found to be substantially lower than an unjacketed control specimen. Failure mode of the jacketed specimens was also undesirable, involving complete tendon rupture and sudden loss in capacity IntroductionSeismic loading of concrete pile shafts can result in a demand for inelastic response. In the case of a superstructure supported by a single pile (i.e., a pile-column forming a single-column bridge pier, in which there is no rotational restraint at the top of the pile}, a plastic hinge will form below grade, at a depth which varies with soil properties and above-grade height of the center of seismic mass.In the case of a superstructure supported by multiple piles, there is rotational restraint, and the connection will experience inelastic action first. However, development of the full lateral inelastic capacity of the pile may call for the formation of a second, subgrade plastic hinge (fig. 1 )."

Jan 1, 2005

By H. R. Masoumi

This paper presents a numerical model for the prediction of free field vibrations due to vibratory and impact driving. As the focus is on the response in the far field, where deformations are relatively small, a linear elastic constitutive behavior is assumed for the soil. The free field vibrations are calculated by means of a coupled FE-BE model using a subdomain formulation, proposed by Aubry and Clouteau (1992). The model is validated by means of the results of Kaynia and Kausel (1991) for the impedance of a single pile. First, the case of vibratory pile driving is considered, where the contributions of different types of waves are investigated for several penetration depths. The results show that in the near field, the response of the soil is dominated by a vertically polarized shear wave, whereas in the far field, Rayleigh waves dominate the ground vibration and body waves have been importantly attenuated. Second, the case of impact pile driving is considered. A linear wave equation model is used to estimate the impact force during the driving process. Furthermore, it is investigated how the soil stratification influences the ground vibration considering the case of a soft layer on a stiffer half space. The results show that when the penetration depth is smaller than the layer thickness, the layered medium has a small influence. However, when the penetration depth is larger than the layer thickness, these effects become more significant. Finally, the computed ground vibrations are compared with experimental data reported in the literature.

Jan 1, 2006

By Alexander Scheuermann, Martin D. Larisch, David J. Williams

"Drilled displacement piles (DDP) have been used around the world for decades as foundation elements for structures and embankments. Typically the pile toes are designed to penetrate into stiff or dense soil formations to achieve sufficient base resistance. Recent research at The University of Queensland in Brisbane, Australia has discovered that the in situ stress conditions in stiff to hard clays is directly related to pile installation rates, which in turn are a function of the piling rig capacity and ground conditions. With adequate and constant pile penetration rates in situ stress conditions in the stiff to hard clay are increased by about 40%, resulting in significantly higher pile capacities. If pile penetration rates are too slow the in situ stress conditions are reduced considerably by remoulding and shearing of the clay, potentially causing reduced pile capacities. The paper presents the results of full-scale test piles at a stiff to hard clay site installed using different full-scale piling equipment.INTRODUCTIONDrilled displacement piling (DDP) is a piling technique in which a hollow stem, fitted with a purpose built displacement tool at the bottom, is drilled into the ground. Dissimilar to non-displacement piles, like Continuous Flight Auger (CFA) piles or conventional rotary bored piles drilled with kelly bars, the soil is not excavated during the DDP penetration process, but is displaced laterally and to a lesser extent vertically. The cavity created by the drilling tool is filled with highly workable concrete during the extraction process. The DDP technique is very economical providing high production rates and creating only marginal drill spoil, which has led to its increased global usage during the last decade. The typical DDP installation process is described in Figure 1."

Jan 1, 1900

By Adnan A. Malik, Tadashi Maejima, Jiro Kuwano, Shinya Tachibana

"The helical piling system provides solution to many geotechnical related problems due to its quick installation, higher compressive and pullout resistance, no wastage of material, workable in limited areas and reusability. However, its use as a foundation for bridges and high-rise buildings is still limited as compared to other piling methods. In the present study, the performance and load settlement behavior of screw and straight pile is investigated under cyclic compressive load in dense ground conditions. To achieve the set objectives, pile load tests were conducted in a cylindrical steel container. The model ground was compacted with dry sand at relative density of 80%. It is observed from the test results that screw and straight pile resistance reduced when the cyclic load is applied at allowable pile resistance state. The reduction in the ultimate pile capacity is more in straight pile than in screw pile. However, straight pile showed higher ultimate pile capacity than screw pile under similar pile tip diameter. The effect of helix bending deflection on load settlement behavior and ultimate pile capacity increases under cyclic loading.INTRODUCTIONScrew pile is one of the new developments in deep foundation, which is growing tremendously fast because of its quick installation technique, less noisy operation, no wastage of material and involvement of minimum manpower. Screw piles have an edge on straight pipe piles due to its high bearing capacity and uplift resistance. The installation mechanism of screw pile is different from straight pile. Torque and pressure is required to install the screw pile whereas hammering, pressure and vibration is required to install straight pile. As the installation mechanism is different between screw and straight pile, therefore, the ground disturbance that is produced during their installation is also different. The ground disturbance produced during the installation also depends upon the pile tip condition i.e. open or closed ended. Sakr, (2009) stated that the compressive capacity of screw pile in 3 to 5 times higher than driven piles having the same shaft diameter and length. The reason for this increase in pile capacity is due to helix, which is generally 2 to 2.5 times the pile shaft diameter. Larger helices can give higher end bearing capacity but it requires very powerful machinery to install in dense grounds. For instance, if large helix screw pile is installed in a dense ground then helix-bending deflection will start affecting the end bearing capacity (Yttrup and Abramsson, 2003; Malik et al. 2013 and 2015). According to Malik (2015), the equations of thin plate (Young and Budynas, 2002) with uniformly distributed load on the plate can give reasonable estimation of helix deflection due to dense ground conditions."

Jan 1, 2016

By Ernest Naesgaard

Post-grouted micro-piles were used for the seismic upgrading of the Vancouver International Airport Domestic Terminal Building (DTB). The micro-piles provided vertical resistance to both uplift and compression loads to supplement the existing timber pile foundations ability to resist the earthquake induced forces, and to provide foundation support at locations where the installation of traditional driven piles was difficult. This paper describes the site conditions, design rationale, installation method and quality control testing procedures. Site and Subsurface Conditions Vancouver International Airport is located within the central portion of Sea Island, Richmond, British Columbia (Fig. 1). Sea Island is bordered by branches of the Fraser River on the northeast and south sides and the Strait of Georgia along the west side. The natural grade of the island is part of a large delta that has been built up over several thousand years. The general pattern of sediment deposition has followed the direction of the Fraser River flow from east to west, and has built up soft sediments of about 200 m thickness at Sea Island (Luternauer, et al. 1993, Mathews and Shepard 1962). The original grade in 1962 prior to the existing Airport Terminal Building development was at about geodetic elevation 1.1 m with a grass and topsoil cover.

Jan 1, 2004

By Ivan Hee

The 2.5km long bridge over the Beauharnois Canal and St. Lawrence Seaway is a major structure in the new Autoroute 30 project near Montreal. Foundations for the bridge consist of footings on bedrock, driven piles, and drilled shafts. This paper describes the design, verification, and construction of 1.85m diameter drilled shafts socketed into very strong and abrasive dolomitic sandstone. Two loading tests on sacrificial, heavily-instrumented, 1.18m diameter test shafts using Osterberg load cells were performed, with telltales installed to monitor a possible rock cone failure mechanism. The loading tests resulted in a revision to the initial design and provided a greater understanding of the cone uplift mechanism in rock. Insights gained are discussed and economies of the load testing program presented. Construction methodologies are also presented.

Jan 1, 2011

By Frank Albrecht, Brian McCarthy

"The Ararat Terminal Station (ARTS) is located 190km to the north-west of Melbourne, approximately 1.7km to the north of Elmhurst Township in the Pyrenees region of western Victoria, Australia. The site occupies an area of approximately 7.2 hectare of farmland. The electricity generated by the Ararat Wind Farm is directed to the ARTS terminal station before being connected to the grid. The ARTS structural design includes more than 180 steel yard support structures, three 25m-tall gantry ‘A’ frames, three modular control room buildings, a precast transformer bund, precast fire wall structures and related foundation design. Innovative driven engineered glue laminated timber (glulam) piles in a cruciform shape were used to reduce the foundation construction time, cost and the amount of concrete used in the project. It is the first time that engineered timber piles made from farmed Australian pine trees have been used in a large-scale environmentally-friendly project. Durability of the timber was achieved by H5 treatment and the use of reinforced concrete pile caps to protect the cruciform timber piles at the ground line. A pile-driving sequence was developed based on field trials. The lateral load capacities of the piles were estimated using engineering principles and from full-scale tests in the field. This paper provides an overview of details of engineered timber cruciform piles, durability of timber piles, design information, pile construction procedures, pile-driving procedures, the testing protocol, test results and validation. The test results were compared with predictions from several methods. In addition, potential future applications of similar systems in other infrastructure projects, and opportunities for future improvements are discussed. The structural aspects of this project were presented in a previous paper at the World Conference on Timber Engineering in Vienna in August 2016. See http://wcte2016.conf.tuwien.ac.at/home/ for further information."

Jan 1, 1900

By Partha Sircar

"For Berth 22 modifications at the Port of Oakland, nearly 600 octagonal 24-inch ‘diameter’ precast-prestressed concrete piles were driven, some piles over 160 feet long. Prior to production pile driving, an indicator/test pile program was performed, which included extensive use of dynamic load testing with (Pile Driving Analyzer (PDA) & CAPWAP analyses. The indicator test-pile program resulted in requiring significantly longer piles than the original design based on subsurface borings. The cause of this discrepancy is investigated in light of the available geotechnical information, soil mechanics principles and standard techniques for pile capacity computations. Several interesting phenomena emerged. These include relatively low resistances offered by crushed rockfill than would conventionally be assumed, non-homogeneity of an apparently uniform formation and the effects of jetting on pile side friction. Also revealing was the significant increase in capacity between 1 and 3 weeks of driving for long piles in clay. Recommendations were developed for pile capacity for future use as “lessons learned”.IntroductionThe foundation for the replaced Berth 22 structure at the Port of Oakland in California involved driving approximately 570, 24-inch octagonal precast prestressed concrete piles. A plan and a section for the pile locations are presented in Figure 1.The ultimate loads on the piles used in the design are presented in Table 1 – the loads are quite heavy.The foundation design was followed by an extensive Indicator Pile Program. The contractors (Manson Construction Co. of Richmond, California) opted to use a Delmag D62-02 diesel hammer (Rated Maximum Energy – 165 kip-feet). Per the project specifications, the same hammer was used for both indicator and production pile driving. The production piles of appropriate lengths were ordered based on thr results of the Indicator Pile Program. A number of interesting results were found from the Indicator Program, which is discussed in this paper."

Jan 1, 2015

By David M. Rempe

The purpose of this standard is to provide a method for testing of cushion materials that leads to uniform results when employed by various organizations and laboratories. The load-deflection characteristics measured using this method are intended to provide input data for analysis of pile driving, as in wave equation analysis of pile driving. It should be recognized, however, that there are several factors which may cause a difference in performance between the test samples under laboratory conditions and actual cushion materials under pile driving conditions. These factors include variations in material properties from sample to sample, compaction and/or deterioration of the materials with use, eccentric loading due to misalignment, confinement effects or the cushion container or inter layered materials, head buildup, rate of loading, etc. In order to obtain representative load-deflection characteristics, therefore, testing of cushion specimens which have been subjected to actual pile driving conditions is encouraged 1 such specimen should be tested at various stages of the useful life of the cushion. The users of the data are cautioned to determine if the particular wave equation program they are using requires either the secant or tangent definition of the stiffness and modulus of elasticity.

Dec 1, 1984