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By Yihan Liu, Jintao Zhang, Chen Xiao, Xiaomeng Zhao, Guanglei Song

To estimate the performance of the inert anode materials based on NiFe2O4 spinel ceramic during it used for aluminum electrolysis, we investigated the wetting process of cryolite molten salt which is in composition of industrial aluminum electrolysis with carbon anode and NiFe2O4 based cermet materials, by means of determination the interface wetting angle between the molten cryolite electrolyte and the solid anodes interface. The results show that the wetting angle between the electrolyte and carbon anode is larger than 90 angulation, this means that they basically can not wetting; however the nickel ferrate spinel ceramics behaves much better. In regard to the NiFe2O4 matrix materials, their initial wetting angles is 76.9. The initial wetting angles for 1.0wt%MnO2, 2.5wt%TiO2 and 0.5wt%V2O5-doped samples are respectively 56.86°, 52.98° and 51.93°. However, after 50s later, all the wetting angles came down below 15°.

Jan 1, 2015

By Harry Thompson

In using explosives to blast stumps from the ground in order to prepare it for farming, it is comparatively easy to place the charge under a stump having a semitaproot or a lateral system of rooting by boring or digging a hole in the earth to a point under the center of resistance and deep enough to give the desired effect.1

Jan 1, 2015

By A. McLean, M. Barati

In this paper, examples are presented of pyrometallurgical research and associated teaching activities during the past century within the Department of Metallurgical Engineering, now the Department of Materials Science and Engineering, at the University of Toronto. Throughout these years, pyrometallurgical research has been characterized by recognition of the importance of the interdependence of measurements and models as well as the development and application of sensors, for the generation, validation and practical implementation of new knowledge. The important role played in the delivery of lectures and participation in joint research by Adjunct Professors with strong backgrounds in the pyrometallurgical industry is described. Projects conducted in close collaboration with the industrial sector and opportunities for students to obtain practical experience working as teams on a "round-the clock" shift basis within an industrial pilot plant environment are outlined. These activities, together with the involvement of students in poster competitions and the presentation of papers at society conferences and technical meetings, are still vital elements in the development of pyrometallurgists equipped with the appropriate professional skills for subsequent employment within academia, government laboratories or the industrial sector.

Jan 1, 2015

By A. McLean, W. Q. Chen, W. Yan, M. Barati, Y. D. Yang

In order to maximally remove the harmful impurities phosphorus and reduce the loss of valuable elements from Si-based alloy for production of solar-grade silicon, thermodynamic properties of the Si-based alloy were studied. In this work a new model, the Molecular Interaction Volume Model (MIVM) derived from statistical thermodynamics, was successfully used in the Si-based and Si-Fe-based alloy. The calculation started from binary Si-Fe, Si-P and Fe-P systems, then the thermodynamic parameters of ternary systems could be derived based sub-binary systems. Using the activity coefficients of the elements in the Si-based alloys and the saturated vapor pressure of the pure substance of the components, mass fraction of P during vapor-liquid equilibrium can be calculated. The calculated thermodynamic parameters were compared with experimental data available in different publications, and it is found that the thermodynamic parameters calculated using MIVM model are in good agreement with the measured results. The calculated result shows that the mass fraction of phosphorus during vapor-liquid equilibrium of Si-Fe-P melt increases with the increasing phosphorus content and decreasing temperature. This is an important direction for experimental practice in vacuum or low-pressure EML refining of ferrosilicon for potential production of solar-grade silicon without significant vaporization loss of valuable element.

Jan 1, 2015

By C. Díaz, M. Barati

Prof. Torstein Utigard's untimely death, in the spring of 2012, put an abrupt end to a meritorious career in the field of high temperature chemical process metallurgy. As an academic in the Department of Materials Science and Engineering of the University of Toronto, Torstein made solid contributions to the advancement of knowledge pertaining to production and refining of both nonferrous and light metals, and to the development of inquisitive and innovative young people in extractive metallurgy. In this profile, the authors highlight aspects of Torstein's rich personality and of his contributions to his field of expertise.

Jan 1, 2015

By S. A. Smith-Hamm, E. A. Sarver, A. S. Cox

Appalachia is an increasing concern, as unnaturally high TDS and/or associated specific conductivity (SC) may contribute to deteriorated stream ecosystem health. The aim of this preliminary study was to explore the efficacy of accelerated leaching as a means of minimizing long-term TDS/SC generation by problematic overburden materials. Five spoil samples were collected and leached using simulated rainwater solutions under ambient and acidified pH conditions. SC and pH were monitored during each leach cycle, and inductively coupled plasma-mass spectroscopy (ICP-MS) was used to determine how leaching conditions affected the release of specific ions. This paper highlights the results of both jar and column leaching tests. Among the most significant findings was that for certain spoil materials, the SC in the leach column effluent was effectively reduced when the spoil was first leached with acidic rainwater followed by ambient rainwater, as opposed to leaching with ambient rainwater alone. This suggests that accelerated leaching might aid in the long-term stabilization of some materials.

Jan 1, 2015

By R. V. Ramani, K. V. Raj, S. Bandopadhyay

The air flow problems in openpit mines are complex. Computational fluid dynamics (CFD) models can provide detailed information regarding air flow pattern, velocity distribution, temperature, and pollutant concentration in an enclosed domain of an openpit mine. A range of turbulent models can be selected with varying complexity and accuracy. Pollutant transport models, however, differ in their assumptions and structure as well as in the algorithms they use. As a result, predictions vary from model to model. This paper presents a study of pollutant transport in an actual openpit mine under a stable boundary layer. The objective was to test two turbulence models using similar geometry and the same input conditions and model constants. Measured data were used to compare the results of the two CFD models, namely, the kappa-epsilon (к-є) model and the Large Eddy Simulation model. Despite the complex synoptic situations, different meteorological input data and fast-changing conditions, the simulation results from both the models were in good agreement regarding the dispersion of pollutants.

Jan 1, 2015

By Chee S. Theng

As the 2015 president of the Society for Mining, Metallurgy & Exploration Inc., I am pleased to present the 2015 issue of the Transactions of the Society for Mining, Metallurgy & Exploration Inc., Vol. 338. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME. Those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2015 Transactions contains some of the most interesting research and insights from the past year and features an international slate of authors spanning industry, academia and government. Papers include the latest findings from the U.S. National Institute for Occupational Safety and Health (NIOSH) and special-focus articles on gold processing, iron ore processing and coal processing. The 2015 Transactions consists of a total of 67 technical papers, encompassing all 22 papers published in 2015 in the Technical Papers Section of Mining Engineering (Vol. 67) and all 29 papers published in 2015 in Minerals & Metallurgical Processing (Vol. 32). Additionally, this volume contains 15 papers and one discussion that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All of the technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2015 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2015

By F. Calizaya, M. G. Nelson

This paper presents a summary of basic requirements for the design, installation and operation of booster fans in coal mines, especially in deep and/or extensive mines. It includes a brief description of the major steps that should be followed to ensure that these units are used in coal mines safely and efficiently. The guidelines were prepared based on the standards and regulations adopted by two prominent coal mining countries, the best practices developed by the mining industry, and the applicable standards used in the United States for the fail-safe operation of main fans.

Jan 1, 2015

By Rajarshi Pramanik, Nirjhar Dhang, Dilip K. Baidya

"This paper performs the reliability evaluation of pile foundation under vertical loading condition using the concept of fuzzy set theory. The uncertain parameters are expressed as fuzzy numbers. Monte Carlo simulation technique in conjunction with fuzzy set theory and fuzzy reliability index approach are implemented in evaluation of the probability of failure of pile foundations. The results are validated through some well established methods such as, First Order Reliability Method (FORM), Second Order Reliability Method (SORM), and direct Monte Carlo Simulation (MCS). Response surface method (RSM) is used to approximate the original limit state equation through second order polynomial. The effect of the position of the water table is also highlighted. Finally, the effect of the variation of applied load is examined and it is observed that the fuzzy reliability analysis gives more conservative estimate of failure probability than the other methods.INTRODUCTIONCivil engineering structures, such as high rise buildings, bridges, offshore platforms etc. are always subjected to vertical as well as horizontal loads. To support these structures, pile foundations are generally the solution in most of the situation. It transmits load from the superstructure to soil at a reasonably great depth. This transfer may be by vertical distribution of the load along the pile shaft or a direct application of load to a lower stratum through the pile tip. Different methods are available to estimate the capacity of piles embedded in different types of soil and under the application of vertical and horizontal loading. To consider the variability in soil and other unforeseen able situation, generally a reasonable value of factor of safety is used to estimate the designed capacity of the pile. Recent developments have shown a trend to place the treatment of uncertainty on a more formal basis, in particular by applying the results of reliability theory to geotechnical engineering. Keeping in mind the importance of pile foundation in the engineering structures it is essential to maintain a high structural safety which result in increase in reliability. The probability theory has been proved to be a powerful tool for representing variability in mathematical models. The variability associated with soil parameters and the modeling uncertainties are needed to be considered for the reliability assessment purpose.Recent development (Zhang et al. 2005; Misra and Roberts 2006; Haldar and Babu 2008; Basu and Salgado 2012; Teixeira et al. 2012; Pula and Rozanski 2012; and Chan and Low 2012) showed that the reliability analysis of pile foundations subjected to axial as well as lateral load has been one of the important current research topic in geotechnical field. Probabilistic based performance criteria were quantified for a single pile and pile groups in cohesionless soil by Eloseily et al. (2002). A p-multiplier approach was incorporated into the analysis to modify the p-y curve for a single pile to obtain the p-y curve for individual piles in a pile group. A statistical analysis of set up capacity of pile was carried out from the database of a large number of pile testing data in clay by Yang and Liang (2006). Load and resistance factor design (LRFD) using FORM was used for examining the different load and resistance factor for different target reliability index. Limit state analysis of drilled shaft was performed by Misra and Roberts (2006) in probabilistic framework. The fuzzy based reliability analysis (Dodagoudar and Venkatachalam 2000; and Park et al. 2012) of the earth slope was reported in the literature. Dodagoudar and Venkatachalam (2000) presented a new approach, called fuzzy point estimate method (FPEM) for reliability evaluation of earth slope. Park et al. (2012) reported a hybrid approach, fuzzy set theory in conjunction with Monte Carlo simulation technique, to determine the failure probability of earth slope. Second Order Reliability Method"

Jan 1, 2015

By S. P. Mukherjee, Smita Tung

"Piles are generally subjected to uplift in case of under ground and water front structures. Sometimes piles are also to resist uplift loads in transmission towers, dry rock, and so on. Experimental investigations of single piles and pile groups have been carried out using model hollow circular aluminum piles, having 25.4 mm outer diameter and lengths of 600 mm, 750 mm and 900 mm. Pile groups of 2?1 and 2?2 arrangements have been used in the experimental investigations. L/d ratio has been kept equal to 24, 30 and 36 in all the cases. All the single piles and pile groups have been tested under vertical uplift. Spacing between two piles in a group has been varied with respect to pile diameter such that spacing to diameter ratios of pile are 3, 4 and 5 in case of pile groups. An attempt has also been made to analyze those models of single piles and pile groups under vertical uplift by PLAXIS 3D software. Good analogy has been observed between the results of experimental and numerical studies. A parametric study has been carried out to observe the variation of ultimate uplift capacity of pile groups with spacing and depth of embedment. It is observed that for a particular embedment length of pile and a particular group arrangement the ultimate uplift capacity increases with increase of spacing. It is also investigated that for a particular spacing and particular group arrangement, the ultimate uplift capacity increases with increase of embedment depth. Those variations have also been presented with graphs which are generated considering non dimensional forms of parameters. The paper brings out change in pullout capacity of pile groups with spacing and embedment depth of piles.1. INTRODUCTIONPrediction of uplift capacity of single piles and especially of pile groups is one of the most interesting areas of research in geotechnical engineering. Pile foundations are frequently used to transmit the superstructure loads to deeper strata if the subsurface soil is of inadequate strength. The worst possible case may be considered to occur when all the piles in a group subjected to uplift. In cohesionless soils, the shaft resistance is an important source of pile capacity under axial loading, especially when the pile is subjected to uplift loading. Poulos and Davis (1980) recommended estimating the uplift capacity of piles as 2/3 of the downward shaft resistance. Later Ramasamy et al. (2004) indicated that the upward shaft resistance is significantly less than the downward shaft resistance. Some studies were conducted on the behavior of a single pile under uplift loads, such as those by Sowa (1970), Vesic (1970), Das and Seeley (1976), Levacher and Sieffert (1984), Rao and Venkatesh (1985), Chattopadhyay and Pise (1986), and Shanker et al. (2007). Das et al. (1976) conducted a model study to test the uplift capacity of single piles and pile groups buried in sand, and they also determined a relationship between the efficiency of a pile group and its spacing. Chattopadhyay and Pise (1986) proposed an analytical method for predicting the uplift capacity of piles embedded in sand and obtained reasonable agreement between experimental and theoretical results. Gaaver (2013) investigated experimentally that an upward displacement of about 1.4–2.5% of the pile diameter is required to attain the net uplift capacity for both single piles and pile groups. The uplift resistance of pile groups depends on the several variables like group size, shape, spacing to diameter ratio of piles, embedment depth to diameter ratio of piles, soil type and its density and soil-pile friction angle."

Jan 1, 2015

By José Carlos do Amaral, Marcelo Groszownik, Jorge Beim

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

Jan 1, 2015

By Sanjay Gupta, Sorabh Gupta, Ravi Sundaram, Abraham Varghese

"Geotechnical investigation for the Kochi Metro revealed a critical section of the Viaduct near Ernakulam Junction Railway Station. Four piers, located over a 220 m stretch, were passing through an area with substantial thickness of soft clay. The scope of the geotechnical investigation included two boreholes and a static cone penetration test at each pier location. In the boreholes, field vane shear test was conducted at different depths in addition to the routine SPT. The design of heavily loaded piles in such strata is a challenge due to the liquefaction of the shallow sands and negative skin friction / down-drag in the soft under-consolidated clay. Bored cast-in-situ piles of 1500 mm diameter extending to 50-60 m depth were used to carry 500-600 tonnes load.INTRODUCTIONThe first phase of the rapid transit system at Kochi, Kerala (See Fig. 1) whose elevated route spans from Aluva to Thripunithura covers a total distance of about 25 kilometers. One of the more critical sections of the viaduct exists near the Ernakulam Junction Railway station where the alignment takes a sharp curve to move towards Vyttila, crossing the railway tracks and running partially over the approach of South over-bridge.In this section, four piers located on either side of the railway tracks near the Route Relay Cabin of Ernakulam Junction Railway Station pass through an area with substantial thickness of soft underconsolidated clay.The alignment is geotechincally challenging due to the presence of loose liquefiable sand and soft underconsolidated and sensitive clay.Initial investigations by the owner based on limited boreholes only yielded conservative and inconclusive pile capacities. For a thorough understanding of the soil behaviour, a detailed geotechnical investigation was carried out to assess the engineering behaviour of the soil strata.The scope of the geotechnical investigation included two boreholes and a static cone penetration test at each pier location. In the boreholes, field vane shear tests were conducted at different depths in addition to the routine SPT."

Jan 1, 2015

By Rick Piovesan, Pramod Rao, Nihal Bohra, Mark Wahler

"This paper discusses the approach followed for the geotechnical design of 355 mm and 457 mm diameter driven open-ended steel pipe piles used for a gas plant at a green field site in Pilbara region in Australia. The principal bearing layer at the site comprises of calcareous Red Bed soils and weak rock, which is the typical geology along a significant length of the northern Western Australian coastline with carbonate content up to 70%. The uncertainty associated with the mechanical behavior of the calcareous soils and cemented soils (weak rocks) presented design challenges in the selection of appropriate pile design method and design parameters for pile capacity estimation during Front End Engineering Design (FEED). The American Petroleum Institute (API)-based design methodology was adopted. The representative design parameters for the Red Bed weak rock were established by treating the weak rock as clay with undrained shear strength as one-half of the characteristic unconfined compressive strength (UCS) value. Both statically load tested and CAPWAP (Case Pile Analysis Wave Program) estimated ultimate axial pile capacities on 25 early pre-production indicator piles demonstrated that the API design methodology for siliceous soils provides reasonable prediction of axial pile capacity in the red bed soils/weak rock and no reduction to API computed axial capacity due to carbonate content is warranted. The results also demonstrated that penalizing axial pile capacity solely based on carbonate content is not appropriate.IntroductionA gas processing facility was proposed to commercialize the gas reserves located 130 km offshore from the north-west coast of Western Australia (WA). The project site is a green field site located in the Pilbara region along the northwest coast of WA. Specific information regarding the site has been withheld due to confidentiality reasons. The site layout is shown in Figure 1.The site comprises low-lying tidal flats, clay pans and sand dunes covered with low scrub. The onshore site levels vary from elevation 1 m to 10 m AHD (Australian Height Datum), with the largest proportion of the area (excluding sand dunes) between elevations of 1 m and 3 m.The onshore facilities are to comprise a liquefied natural gas (LNG) plant site, a construction camp, the land-based portion of the materials offloading facility (MOF), roadways, and borrow pit areas.The existing ground levels within the process train area, where pile load testing was performed, vary from over 7 m AHD where the summits and peaks of the central dune exist to typically 1 m to 2 m AHD towards the east and west edges of the dune. The proposed finished grade for the process train is set at 7 m AHD."

Jan 1, 2015

By Daniel W. Mageau, Larry W. Applegate, Aaron K. McCain

"An innovative method of ground freezing was successfully tested to create a “dry” excavation condition for a new building foundation at a site in downtown, Miami, Florida. The subsurface conditions in Miami generally consist of very porous, weak limestone and sand with groundwater near the surface. Water flow through these materials can be very high. Dewatering is extremely restricted in Miami so deep below-grade structures are rare and expensive. A new, innovative method to allow deep excavations in dry conditions without dewatering involves the creation of a thick, temporary, frozen soil plug below the planned excavation depth across the entire site to cut off vertical groundwater flow during construction. Frozen soil is impermeable and very strong and has long been used for temporary structural and water-tight shored walls. Using the same proven principals, frozen soil plugs are very effective at cutting off water from the bottom of the excavation as well as resisting upward buoyant forces. This new freezing method can be used for fairly deep excavations in new building construction supported on deep foundations. The building piles act as temporary anchors for the frozen plug to resist very high upward buoyant pressures until the permanent structural slab is completed.IntroductionUnlike other Cities, below grade basements are rare in Miami. The few basement foundations constructed have utilized a cumbersome and expensive method of excavation and shoring involving underwater excavation, tremie slabs, and commercial divers. The key issue for underground construction in this area of the country is the vertical flow of groundwater through the base of the excavation. To deal with this issue in the past, the contractor first installed all of the building piles and the perimeter shoring walls. Then, interior sheet pile walls are installed to create small manageable excavation pits. Each pit is then excavated through standing water “in-the-blind” and around the buildings support piles. The final excavation, interior struts, and inspection is performed by commercial divers. Finally a thick foundation tremie slab is poured under water. This method could be successful but proved to be time consuming and expensive. In addition, some building piles were occasionally damaged during the under-water construction process."

Jan 1, 2015

By Anup Kumar Mandal, Sanjoy Chowdhury, Biswajit Das

"Tailing pond of an iron ore mine necessitated raising the height of its embankment to create additional storage capacity. The tailing pond is located in eastern India and raising the height of embankment was going on during the month of January, 2014. Upstream method of construction was adopted since there was no space available at the downstream side. During the construction, about 200 m stretch of the north east embankment of height about 5.5 m failed forming a classical slip circle on the upstream side involving about half the top width of the embankment. To find out the root cause of the slope failure, detail geotechnical investigation work was carried out within the embankment as well as in the adjacent areas within the pond. About 7.5m thick very soft tailings were detected below the constructed embankment. Shear strength of the soft tailing was very low and was inadequate to sustain imposed embankment load. This resulted in the failure of the embankment. Analysis of the tailing deposit revealed that even after failure, settlement was continuing due to imposed embankment load. Under normal onedimensional consolidation, the tailing deposit would have taken about 5.7 years for 90% of primary consolidation. However, in order to mitigate the scarcity of storage space, mining plan required raising the height of the embankment within next six to eight months. Therefore, despite the fact that there was a failure, it was necessary to continue the construction on the underlying weak stratum. The system was redesigned with installation of prefabricated vertical drains (PVDs) to accelerate the consolidation process thereby gaining the in-situ strength. Strength was additionally enhanced by installing geogrids in multiple layers. It stabilized the existing embankment and also ensured construction of additional height over and above the existing embankment.INTRODUCTIONBeneficiation plant in the Iron mines enhances the mineral content by separation of contaminants and fines. The residue (waste material) is called tailings/tailings depending upon the grain sizes. These tailings in a slurry form are generally disposed in a pond called as tailing pond/tailing pond. Height of embankment of such ponds is increased either by upstream or by downstream or by centrally raising methods in different phases as quantum of deposition in the pond increases with time."

Jan 1, 2015

By Brandon Buschmeier, Frederic Masse

"Inclusions are a type of ground improvement that provide an improvement of a soil mass by insertion of a material with better characteristics than the surrounding soils. There are primarily two types of inclusions: “Soft” inclusions which are constructed of granular material (Stone Columns, Rammed Aggregate Piers, VibroPiers...), and “rigid” inclusions which are constructed of grout inserted with or without pressure (VibroConcrete Columns, Controlled Modulus Columns, Soil Mixing Columns).While the central principle of the inclusions is similar (i.e., overall improvement of characteristics of the soil mass below the structure), the load transfer mechanism is radically different for each technique. Therefore, the applicable design methodology is specific to the type of inclusions and there exists no universal method of design which spans across all inclusions.This paper will present an in-depth comparison between the standard design methods used for “soft” granular-type inclusions (Priebe modified, Balaam & Booker, Goughnour & Bayuk...) and the methods used for “rigid” inclusions which mainly rely on finite element analysis. The paper will explain why the design for soft inclusion methods cannot be applied to rigid inclusions and vice-versa. Each design method will be reviewed in detail to better emphasize its limitations and advantages.Two case histories will also be presented; one for each type of inclusions in order to illustrate the concepts developed in the first part of the paper.1 INTRODUCTION1.1 GENERAL OVERVIEW OF GROUND IMPROVEMENT WITH INCLUSIONSThe use of ground improvement methods to provide the appropriate amount of foundation support is a growing and constantly evolving industry. Traditional structural foundation methods including ‘shallow’ and ‘deep’ foundations do not adequately address the wide range of settlement tolerances, soil conditions, and loading considerations inherent to each unique potential project. In some instances, ‘shallow’ foundation solutions are simply not feasible due to soil and loading constraints. Furthermore, ‘deep’ foundation solutions are used to ‘bridge’ the soft compressible soils, ensuring that the entirety of the load in the structure is transmitted through individual elements into competent layers below the ground surface (bedrock, dense residual soils). Highly concentrated structural loads are transferred into the individual elements by means of direct contact requiring the use of structurally rigid surficial components (structural slabs, grade beams, and pile caps).Ground improvement bridges the gap between these two traditional methods, offering adequate foundation support while using more costeffective techniques and design methodologies. Inclusions are a type of ground improvement used to provide a reinforcement of the soil mass through the vertical insertion of a material with better characteristics than the surrounding soils. Much like deep foundations, inclusions are installed through soil layers with high compressibility and/or low bearing capacity and terminated in a suitable bearing stratum. However, unlike deep foundations, ground improvement inclusions rely on a distribution of load between the soil and the inclusions. By doing so, some of the structural load is applied directly to the soil in a proportion equal to its bearing capacity and compressibility limits, while the rest of the load is shed into the vertical inclusions down to the bearing stratum. Load sharing is a critical aspect in the performance and design of the various ground improvement methods."

Jan 1, 2015

By Abu B. Siddique, Anthony S. Crincoli

"The New Jersey Turnpike Section 2 widening program consisted of widening between Interchange 6 in Mansfield Township, Burlington County and Interchange 9 in East Brunswick Township, Middlesex County. To accommodate large volume of traffic the roadway was widened from 6 to 12 lanes with major modifications performed at four interchanges. The Section 2, NJTA Interchange 6 to 9 Widening Program is a 4.2-mile section of Turnpike roadway which included a total of 12 new or modified structures. In order to facilitate the construction process Section 2 was divided into three construction contract packages. This paper will cover the last and final Contract T869.120.203 which is 1.7 miles in length. The work generally consisted of eight new ramps connection to and from the toll plaza to the new inner and outer roadways. New mainline bridges were constructed over several ramps. A new bridge was constructed to take northbound outer lanes traffic over two ramps along with new mainline bridges over Black’s Creek, Georgetown Road, and Laurel Run. In addition, a new bridge was constructed to take a ramp over Laurel Run and the existing U-turn Bridge was replaced with a new one.For Contract T869.120.203 a total of 74 five-foot diameter drilled shafts has been constructed to support all pier foundations for bridges. Three drilled shafts were tested using Osterberg Load Cells to verify the estimated shaft resistance during design phase. One Osterberg Load Cell test was performed on a demonstration (sacrificial) shaft and the other two Osterberg Load Cell tests were performed on production shafts. This paper compares the estimated total, side and tip resistances with corresponding measured total, side and tip resistances and provided recommendations for future design purpose.INTRODUCTIONTo accommodate large volume of traffic the New Jersey Turnpike Authority (NJTA) decided to widen Section 2, which included Interchange 6 through Interchange 9. The Section 2, a 4.2-mile section of Turnpike roadway that was widened from 6 to 12 lanes with major modifications performed at four interchanges.The New Jersey Turnpike Authority (NJTA) procured AECOM to perform engineering services for the final design of Section 2, NJTA Interchange 6 to 9 Widening Program. Section 2 is a 4.2-mile section of Turnpike roadway that will widen from 6 to 12 lanes and will include a total of 12 new or modified structures. It encompasses modifications of the existing and the design of four new ramps at Interchange 7. The project also includes the modification of two local roads over the mainline, two local roads under the mainline, two maintenance U-turns, and retaining walls. In addition, the project consists of the design of noise walls, sign structures, storm water management basins and the more typical drainage, utilities, lighting, roadway, ROW, and signing and striping design."

Jan 1, 2015

By James L. Christensen, Gregory Sanchez, Michael P. Walker

The Fogg Museum expansion project required excavation and construction in a congested urban area in Cambridge, Massachusetts. A soldier pile tremie concrete (SPTC) wall provided the support of excavation and now serves as the permanent basement wall of the new expansion of the museum. The existing Fogg museum had a single basement level. The new expansion has a two-level basement for new exhibit space and an amphitheater. The east side of the site is about 20 feet above the basement level of the existing Fogg structure which resulted in a significant unbalanced load that needed to be resolved without damaging the original Fogg structure. The SPTC wall was supported with a combination of tiebacks and internal bracing. The final depth of the excavation was about 40 feet below street level. Strict movement control was imposed because the existing museum contained an Italian Renaissance-style courtyard. The southeast corner of the SPTC wall had to accommodate underpinning of an historic concrete ramp which was ultimately incorporated into the expansion. Challenges during construction included excavating the SPTC wall panels up to 12 feet into argillite bedrock which had occasional diabase dikes and sills. The following topics are discussed in more detail after a general project.

Jan 1, 2015

By Terrence M. Carroll, Chu E. Ho

"A pile installation and load testing program on driven tapered piles was undertaken at John F. Kennedy International Airport in New York City for the extension of the existing Terminal 4. As part of the program, dynamic testing by means of the Pile Driving Analyzer (PDA) was performed on several preliminary test piles as well as production piles. The results of the dynamic tests and subsequent static load tests were reviewed to develop an understanding of the pile-soil response of a tapered pile during driving and after setup. Pile setup occurred as a result of increase in shaft resistance with virtually no increase in toe resistance. More than 150 tons of additional capacity was gained after the setup time.The capacities measured during driving from the PDA are typically used as the basis for determining the pile driving set criteria, with the required initial driving capacities determined largely by the contractor’s experience. An improved appreciation of the setup phenomenon is required to better refine the driving criteria at the end of initial driving such that the required ultimate capacities can be obtained, with reasonable confidence, after a period of setup.This paper presents interpretation of pile-soil behavior from Case Pile Wave Analysis Program (CAPWAP) analyses and discusses the mechanism of increased capacity as a result of setup effects. Time-dependent capacity gain as a result of setup effects should be based on the extrapolation of the shaft resistance component rather than the total pile capacity as is commonly practiced. Prediction of pile performance using this approach was in good agreement with observed static and dynamic load test results.IntroductionTapered piles have been adopted for various projects at John F. Kennedy International Airport (JFKIA) since the late 1940’s. Initially timber piles were used exclusively, with steel Monotube piles being used from at least the 1980’s (Horvath and Trochalides, 2004). The steel Tapertube pile was developed in the mid-1990’s and has commonly been used in recent construction (Brusey and Yin, 2008). The Tapertube piles used for this project consisted of a 25 foot long tapered section that was 8 inches in diameter at the tip and 18 inches in diameter at the top. An 18 inch diameter straight pipe was welded above the tapered section."

Jan 1, 2015