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By Gerald Verbeek, Erick Baziw

Downhole Seismic Testing (DST) is an extensively utilized geotechnical tool for site characterization. DST provides low strain (<10-5) in-situ interval shear and compression wave velocity estimates. These velocities are determined by obtaining relative arrival times of source waves as they travel through the stratigraphy and are recorded by one or more vertically offset seismic sensors. The DST arrival times have associated measurements errors and resolution limitations, which become more pronounced as the depth interval of analysis is reduced. Baziw Consulting Engineers (BCE) has developed a new DST analysis technique, the so-called DSTPolyKF algorithm, whereby the arrival times of DST data set are used to define a high order polynomial. The main advantages of this new technique are four-fold: 1) the ability to utilize all arrival time estimates irrespective of measurement errors. 2) the ability to analyze the data with user specified and even small (≤ 0.5m) depth intervals. 3) the ability to apply sophisticated data fusion for significantly more accurate DST interval velocity estimation. 4) the use of polynomial regression accuracy parameters to quantify how well the “best fit” polynomial fits the acquired arrival time data sets. This paper outlines the mathematical details of the best fit polynomial where a Kalman filter formulation is implemented. The performance of the DSTPolyKF algorithm is demonstrated by processing real DST data sets.

Oct 1, 2022

By Sudhir Kumar Das

"The exorbitant price of the land in the metropolis has restricted the horizontal expansion and compelled the owners, the developers and the engineers to opt for vertical expansion. This has resulted in the construction of high rises by extending floors of the existing buildings and developing the new ones for which deep excavation is a must. The multistoried buildings up to a certain height can be founded on shallow depth if the soil beneath can withstand the load. If not, the soil can be stabilized by the latest improvement technology to change the properties of soil to cater the desired load of the superstructures. By such practice the cost and time of completion of the substructures can be reduced in comparison to the substructures needed for deep excavation.The necessity of deep excavation cannot be ignored to create housings, underground parking lots and the other public amenities for the urban migrants in the metropolis.Although most of the metropolis have underground mapping the developers, before starting excavation should be hundred percent sure about the alignment and depth of the utilities so that the excavators do not snap the same to bring cut in water supply, power lines, telephone lines etc, resulting in hue and cry in the neighborhoods of the metropolis due to no availability of the essential services The building/structures coming on the influence zones of the deep excavation should be monitored in all sequences of excavations. In case of building underground corridors for rail or road through open deep excavation under a traffic road the developers, before commencing excavation should shift/divert the dry and wet utilities coming on the way of excavation to suitable locations. The surface traffic need to be diverted either temporarily to an adjacent alternative road or allowed to pass over a decking built over the trench of excavation for the affected length of construction. The soil support system is necessary longitudinally on the two sides covering the width of trench for building corridors. In case of building substructures of flyovers built at different plots along the alignment of the flyover or a multistoried complex built at an isolated plot, the soil support system would be necessary on all the sides covering the plot of construction.The material of construction of soil support depends on the depth, type of soil and the type of permanent structure to be developed. Probable geo-hazards inviting casualties in the deep excavation projects occur due to caving of soil, leakage of wet utilities, seepage through honey comb concrete surfaces, failure of pump used for dewatering etc. A detailed comprehensive planning, management and determination of the project authority is essential for marginalizing the casualties. These prevent unforeseen expenditure in mitigation and help to control the time and the cost over run of overall project. The engineer at site should be more a professional manager than an engineer at site. He should be conversant with the safety and environment rules and regulations applicable to deep underground projects."

Jan 1, 2015

By Mike Muchard

STATNAMIC load testing augmented with embedded instrumentation has been successfully used to obtain structural and geotechnical design information on large diameter spun cast concrete cylinder piles on many large marine construction projects. The paper focuses on one particularly interesting large marine project involving a new bridge to St. George Island, Florida where instrumentation and STATNAMIC load testing was used in conjunction with static load testing on high capacity piles. The information presented includes embedded instrumentation measurements taken during pile fabrication (post-tensioning), during pile driving, during static load testing, and STATNAMIC load testing. As much of this data is the first of its kind on concrete cylinder piles, it is exciting to present the foundation industry with this additional insight as to the behavior of this pile type and the accuracy of the methods used to test them.

Jan 1, 2013

By Gerald Verbeek, Erick Baziw

Dynamic soil analysis (DSA) in geotechnical practice is intimately related to the capability of measuring the necessary soil properties of shear modulus and absorption. In DSA the methods of analysis are based upon the stress-deformation response of soils due to imposed shear strains. Typically the soil profile is numerically modeled as linear visco-elastic system. This technique is referred to as the Equivalent Linear (EL) method, and it requires the specification of the input parameters of low-strain (<10-5) shear modulus, modulus reduction, and the equivalent viscous damping ratio, which is directly related to the soil absorption value. Downhole seismic testing (DST) has proven to be a very accurate tool for estimating low strain shear modulus values as long as source wave raypaths are taken into account, especially for near-surface investigations. DST has also been utilized to estimate low-strain interval absorption values. In these cases standard frequency domain absorption estimation algorithms (such as the spectral ratio technique) are utilized where it is assumed that the source waves are traveling along the same travel path, which is obviously not the case for near surface DST investigations. This paper outlines a unique DST absorption estimation methodology, which is carried out in the time domain and takes into account source wave travel paths. 1. INTRODUCTION There is considerable interest in methods of geotechnical in-situ engineering that provide accurate estimates of the shear wave velocity and the associated absorption values in the ground, since these parameters form the core of mathematical theorems to describe the elasticity/plasticity of soils and they are used to predict the soil response (settlement, liquefaction or failure) to imposed loads (whether from foundations, heavy equipment, earthquakes or explosions).

Jan 1, 2019

By William D. Oder, Seth H. Hamblin, Les R. Chernatskas, Jonathan L. Ernst

Large diameter drilled deep foundations are a widely utilized solution throughout North America and the world. Numerous design and construction techniques developed over the past 100 years have made this type of foundation a robust, reliable, and efficient foundation option to support a wide variety of structures. From bridges, to marine structures, to high-rise buildings, drilled shafts are a time-tested approach for all types of infrastructure projects. Yet, what remains ambiguous in the current state of engineering practice is how to respond when a shaft is constructed that, for potentially different reasons, may or may not meet the design requirements? In this case, what are the best practices for Contractors and Engineers when a structural, geotechnical, or material integrity issue arises during construction? In our experience the answers to these questions are not widely known, but are profoundly important so that engineers can have tools available to confidently and efficiently address concerns, and provide a path forward for the project. This paper seeks to answer the above questions by presenting details of different remediation approaches using the results of several case studies where structural and geotechnical engineering methods, combined with non-destructive integrity testing (NDT), were employed to evaluate the acceptance of “questionable” drilled shafts. Through multidisciplinary techniques like Cross-hole Sonic Logging and 3-D Tomography which enhance the resolution of anomalous zones and defects in concrete, the development of concrete strength estimates from non-destructive testing data, and executing innovative structural and geotechnical analyses to evaluate the as-built conditions, drilled shafts that might have historically been rejected were ultimately accepted by the project team. This paper presents a series of unique case studies that together depict a roadmap for a comprehensive approach to reliably evaluate and guide the industry to address these types of drilled shaft construction issues.

Oct 1, 2022

By Steven E. Darnell, William W. Haasz, Brandon T. Buschmeier, Frederic Masse

"Landfills often cover expansive areas in locations where large building facilities or infrastructure is in high in demand after the land has been reclaimed. Most landfills have soil or fill properties that vary widely over small distances; combined with the strict guidelines and restrictions for the removal and treatment of soil or material that is on site, these projects can be a major challenge for any prospective developer. In order to make landfills suitable for the construction of any project it is necessary to conduct a detailed evaluation of the subsurface conditions. Ground improvement techniques are among the most typical methods for making reclaimed landfills suitable for the construction of any major project. The paper will discuss the approach that was taken to support a proposed warehouse in Elizabeth, New Jersey using Controlled Modulus Columns Rigid Inclusions (CMC Rigid Inclusions), which are grouted, auger-displacement elements. Additionally, we will discuss the use of Dynamic Compaction (DC) that was performed in areas outside the proposed warehouse footprint. Through the combination of CMC rigid inclusions and DC, the general contractor’s project schedule was expedited, the costs to support the warehouse were economized, and the anticipated settlement of the parking lot areas was drastically reduced. Furthermore, the paper will outline the benefits of using CMC rigid inclusions and DC methods in order to minimize the impact of working with contaminated soils from a landfill.OVERVIEW OF THE ELIZABETH WAREHOUSE PROJECTOver the past several decades the foundations industry has seen an increase in demand for the support of developments on reclaimed landfills; particularly, on the east coast where many landfills were capped before the 1980’s and steady population growth and city expansion have caused high demand for this now highly desired real estate. Unfortunately, these landfills, often as large as twenty (20) or more acres present tough geotechnical and environmental challenges for Owners planning to develop or build structures of any size on the reclaimed land. Consequently, the options for building on reclaimed landfills can quickly become cost prohibitive.Site SpecificSelected by a developer for the location of a future warehouse, the 29 acres (114,424 sq-meters) project site is located in Elizabeth, New Jersey and demonstrates the complexities of designing over a once reclaimed landfill. The landfill was used for municipal solid waste (MSW) consisting of trash, wood, metal, glass, plastic, brick, concrete fragments, and other types of debris. This landfill was capped in the 1960’s, and developed in the 1970’s for a warehouse. The new project included the demolition of the existing warehouse and the development of the site to be repurposed for a new 481,650 sq-ft single-story warehouse, surrounded by paved parking and truck loading areas. Figure 1 below, shows an overview of the project site layout."

Jan 1, 2017

By Brian J. Olson, Kevin Haiar

Originally constructed between 1939 and 1941 as part of Franklin D. Roosevelt’s New Deal programs, the Bonneville to Hood River 115 kV Transmission Line required an infrastructure upgrade to remain reliable and in-service. The line traverses the rugged landscape of the Columbia River Gorge on the Oregon- Washington border, featuring steep, talus slopes; uneven, rocky terrain; and a variety of environmental sensitivities. This paper details the design and construction of 27 micropile foundations for new, fire- hardening steel poles through a particularly challenging stretch of the alignment. The difficult access and environmental constraints at these sites designated them as helicopter-accessible and precluded the collection of detailed geotechnical information prior to construction. Micropiles provided a viable foundation alternative due to their portability and flexibility during construction. Detail will be provided on the extensive preliminary desktop study performed, as well as the process of developing engineering designs to successfully accommodate for variability and unknowns in complex geological conditions. With an increasing number of electric power projects traversing challenging terrain and facing similar obstacles, this project stands to provide valuable lessons learned to the industry.

Sep 8, 2021

By W. G. K. Fleming

The general history of piling is traced up to the present time with regard to the evolution of methods and materials. The processes have been strongly influenced by developments in basic equipment and industrial change. It is noticeable that in the twentieth century more progress has taken place than in the many previous centuries. It has been strongly influenced by the general development of Soil Mechanics. Test loading is probably the most effective way to assess the success of designs and many empirical relationships have been challenged through it. As we approach a new century it appears that it will be an age of rapid equipment development, with much enhancement of understanding of what has been done. Processes of automatic construction and testing will becoming commonplace. These changes will narrow the limits of conventional scatter that have come to be accepted and to a large extent will be driven by political efforts to curtail energy consumption, to raise standards of quality and reliability, and to conserve the environment. 1. Ancient history. Piling is an ancient art. Its first mention in history is from Herodotus, the first person to commit an account of his times to the written word in the years 557 to 479 BC. He evidently had a strong interest in engineering matters because he wrote of building, brick making, reinforced brickwork, river training, canal building, bridge construction, tunnelling and its acoustic detection and piling. The piling reference comes from Book 5 at paragraph 16.

Jan 1, 1999

By P. Arz

With a total of five basement levels, ground floor and a further six levels above grade, construction of the Kö-Galerie building, on the Königsallee, in the centre of Düsseldorf, was completed with all the difficulties which accompany property development today in the inner city. To meet the intermediate and final deadlines, ad­vanced building techniques were used. Notable among them are the top/down method for simultaneous construction upwards and downwards from an intermediate level, and the use of pre-fabricated composite columns in drilled shafts for the main load-bearing foundations as well as diaphragm walls designed as permanent structural wall of the basement.

Jan 1, 1989

By Pierre Gouvin, Michael Oakland

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

Jan 1, 2017

By Michael W. Driller, Wen Yan (Grace) Chen, Steven J. Friesen

"Remediation for Perris Dam has been proposed in response to deficiencies identified in a seismic stability study prepared by the California Department of Water Resources (DWR) in 2005. Lenses of potentially liquefiable soil have been identified within the dam foundation which may lose strength during a seismic event. The remediation was designed primarily to limit deformation of the dam. Nineteen construction methods were compared and evaluated for the remediation. The final decision was to use cement deep soil mixing (CDSM) to strengthen the foundation and to construct a downstream berm to stabilize the dam. The entire CDSM treatment will cover over 4,000 linear feet of the downstream toe of the dam. Over 300,000 cubic yards of CDSM will be used to strengthen the foundation. The construction of the project started in Fall 2014 and is anticipated to take approximately 3 years. This paper describes the design aspects of using CDSM to treat the foundation, including laboratory testing, investigation of overstressing/cracking, extent of treatment, effect of CDSM on pore pressures under the dam, and the results of a full-scale CDSM test section.INTRODUCTIONPerris Dam is a zoned earthfill dam with a length of 2.2 miles, a maximum height of 128 feet, and a capacity of 131,450 acre-ft of water. The dam is located in Riverside County, California at the terminus of the East Branch of the State Water Project. The embankment was constructed between 1971 and 1973 over an alluvial deposit between the Bernasconi Hills to the South and Russell Mountains to the North. A rock outcrop divides the dam into left and right reaches when viewed from the reservoir looking downstream. The embankment soil was obtained from a borrow source at the North end of the reservoir. The dam has a sloping sandy clay core (Zone 1) with a 10-foot deep cutoff trench and a silty sand shell (Zone 2) with a downstream chimney and blanket drain (Zone 3 and Zone 4) as shown in Figure 1."

Jan 1, 2015

By M. Krzaninski, Y. Zou, A. Frost

The foundation solution for a data centre building in Sydney, Australia comprised two alternatives, the first of which incorporated the use of CFA piles founded in rock at approx. 27m depth to support column working loadings of approx. 7.5MN, and the second utilising rapid impact compaction with a raft foundation of 1.0m thick concrete slab. Soil conditions comprised 1m of fill over 3 to 4m of sands varying from loose to dense consistency, underlain by very stiff clays overlying the rock. A creative solution incorporating Rapid Impact Compaction to improve the loose soils in conjunction with a piled raft solution was proposed. Piles proposed under the raft were Atlas Drilled Displacement piles which offered advantages of displacement pile performance and savings in time and material costs. The piled raft solution was developed in consultation with the consulting structural engineer, combining the skills of the piling contractor and consulting engineer to the benefit of the project. This paper describes the development and design aspects of the piled raft solution adopted for the project.

Nov 1, 2022

By Dario Libano, Franz-Werner Gerressen

"Diaphragm walls are known as underground structural elements commonly used for retention systems and permanent foundation walls or elements. Of course they can also be used as deep groundwater barriers. This paper will focus on the construction work in an urban area like Sao Paulo. The Line 5 of Metro Sao Paulo is one of four network expansion projects undertaken at the same time. The projects will cover various areas of the city. The Line 5 on São Paulo’s south-side will be extended 7.1mi (11.5km) to serve 770,000 riders per day, stretching a total of 12.4mi (19.9km) along 17 stations. The extension line will facilitate access to the city’s central section and the commercial and hospital districts located along the line. The Brooklin Station, subject of this paper, had to be carried out in a special five shaft shape design, shaft diameter 131ft (40m) each, without using ground anchors. A focus will be taken on the special requirements of the installation of the arrows as well as on the specialties of installation for the shaft shaped layout. Therefore, it was required to install a 3.3ft (1,000mm) diaphragm wall using a specific layout especially in the connecting sections of the shafts, the so called arrows, to provide a bearing area for the struts. Maximum wall depth was about 121ft (37m); the total volume was about 20,060 cubic yard (15,337m³). The paper will describe the construction method and the sequence of activities required for the construction of this diaphragm wall using a combination of hydraulic grab and trench cutter system.INTRODUCTIONThe Line 5 Extension, in the city of Sao Paulo/Brazil, is currently the most important investment in public transport by Sao Paulo state’s government. It will connect the south part of the city to the city center, crossing through four other major METRO lines and stations, all currently in operation. The extension includes a new parking yard for the trains and 11 new stations. The Brooklin Station is one of the new stations and has a unique geometry of five secant shafts. The station should open and operate in 2016.The original design included constructing five secant shafts stabilized by two plastic slurry walls using conventional grab technology. One of them was to contain the contamination plumes in the neighborhood and the other for temporary support to enable the excavation of the shafts. The final retaining wall design was reviewed and changed to a concrete structural diaphragm wall. The reason of design change was as well the reduction of construction time of the shafts by half to meet the schedule as to avoid dewatering effects in a geological region characterized by Quaternary sediments and environmental contamination plumes. It was the first time that a trench cutter (hydromill) was used in such a situation in Brazil. The cutter increased the quality of the joints by overcutting, and decreased the probability of having seepage into the shafts. The cutter created a seepage barrier and avoided movement of contamination."

Jan 1, 2017

By Kiyotaka Ohno, Nobushige Yasuoka, Yosuke Hioki

"The diameter of improved columns adopted by the original DJM Method had been 1000 mm, however, in order to comply with the social need for construction cost reduction, the Expanded Dry Jet Mixing (EX-DJM) Method with maximum column diameter expanded to 1300 mm was developed between 1998 and 2001 and has been widely applied since then. From the first application of EX-DJM in January 2002 for a first construction project, the total volume of improved soil has reached 325,000 m3 in 17 projects up to September 2014. Because of the advantages of the EX-DJM such as reduction of construction costs and periods leading to reduction in the number of improved columns, adoption of this method is expected to increase in the future. This paper describes the advantages of the EX-DJM, its construction results and case examples including those applied to restoration projects after the Great East Japan Earthquake, 2011.1. BACKGROUND OF DEVELOPMENTThe Dry Jet Mixing (DJM) Method is a soil stabilization method in which a powdery or granular binder is pneumatically fed into and mixed with soft soil to induce chemical reactions that stabilize and strengthen the soil. It was developed by government - private collaboration in Japan between 1977 and 1979. Up to March 2014, the total volume of soil improved by DJM method reached 33,500,000 m3. The initial diameter of improved columns of the original DJM Method was 1000 mm. In order to comply with the social need for construction cost reduction, the Expanded Dry Jet Mixing (EX-DJM) Method with maximum column diameter 1300 mm was developed between 1998 and 2001.2. ADVANTAGES OF EX-DJMThe construction equipment for the EX-DJM consists of two major parts, which are DJM machine and binder plant are shown in Fig. 1.The construction machine is of double mixing-shaft type with its column diameter expanded to 1200mm or 1300mm. In association with the increase in the column diameter, the binder feeder has also increased its discharge rate by approximately 1.69 times. Same as the increase rate of the area of original diameter 1000mm to diameter 1300mm are shown in Fig. 4."

Jan 1, 2015

By John C. Niedzielski, A. Frances Ackerman

The existing US-70 Bridge over the Gila River at Bylas, Arizona is planned to be replaced due to its current poor condition. The replacement bridge is planned to be a 15-span, 1,904-foot (580 meter) long bridge, the third-longest bridge in the state highway system. Within the Gila River floodplain, granular alluvial soil is underlain by cohesive lacustrine soil; bedrock was expected due to nearby terrain but not encountered within the geotechnical exploration depth of 166.5 feet (51 meters) or less. Based on the anticipated loading conditions, design scour depths and the soil conditions, the full structural loads are carried by large diameter drilled shafts; therefore accurately determining the axial capacity of the proposed drilled shafts has important practical and safety implications. The conventional methods for axial capacity determination may be overly conservative to use for design in the site’s layered granular and hard clay soils. An Osterberg cell load test was performed to obtain detailed information on the load transfer from the drilled shaft in side friction and base resistance to allow optimization of the bridge foundation design. The fullscale field test played a significant role in the design of the project’s deep foundations, notably, by incorporating the specific subsoil properties and consequently, an exact prediction of the load-settlement behavior under loading. This paper provides the results of the geotechnical site investigations, drilled shaft load testing procedures, and shaft load distribution from the load test results. Comparisons were developed between predicted axial capacities of drilled shafts using several design methodologies and the axial capacity measured from static load testing. The load test results showed that underestimation of the axial capacity is evident using conventional methodologies. The exact prediction of the load-settlement behavior under loading combined with a site-specific design approach, resulted in a substantial reduction of foundation costs due to reduced drilled shaft dimensions.

Jan 1, 2017

By Peter Middendorp, Gerald E. H. Verbeek

"This paper will describe a brief history of the method of characteristics as an accurate solution of the wave equation, and the author's experiences with the method of characteristics over a period of 30 years.As a result of the offshore pile driving activities associated with the development of the North Sea oil fields in the 1970's, two Dutch companies initiated extensive research efforts. Heerema started to research the dynamic behavior of soil during driving and HBG (Hollandsche Seton Groep) extended the method of characteristics with a straightforward theoretical solution for the shaft friction along a pile.The research institute TNO started the development of the wave equation program TNOWAVE in the late 1970's based on HBG's friction model extension for the method of characteristics. Today the program has a worldwide application in the field of pile testing. This paper will describe its development and application over time and its relation to today's applications for driveability studies for impact hammers (PDPWAVE) and vibratory hammers (VDPWAVE), signal matching for Dynamic Load Testing (DL TWAVE), Pile Integrity Testing signal matching (SITWAVE), and Statnamic simulation (STNWAVE).The paper will highlight that these developments have been the result of multi-disciplinary and multi-national efforts and encourage geotechnical engineers to seek further developments of the wave equation program in a similar manner. Finally, the paper will indicate some areas where such further developments are required."

Jan 1, 2005

By A. R. Dover

The Richmond San Rafael Bridge (Figure 1) is a 4.3 mile long major toll bridge span across northern San Francisco Bay. Tutor-Saliba/Koch/Tidewater (TSKT) conducted a comprehensive seismic retrofit, which was at the time Caltrans? largest-ever construction contract at $484 million. The robust foundation retrofit design of 11 bridge piers included the installation of 26 new, large diameter (126 to 162 inch OD, wall thickness 1.5 to 2.25 inches) CIDH and CISS piles, with steel pipe piles installed to tip elevations of Elev. ?140 to -220 ft, in water depths up to 70 feet. The open-ended steel pipe piles had initial sections ranging from 71 to 172 feet long, with full lengths that extended to the bay bottom and then through 100 to 130 feet of marine sediments to top of bedrock. The marine soils of most interest consisted mainly of soft to firm Young Bay Mud (YBM), a silty, moderately-sensitive clay common to SF Bay. A key constructability issue was the prediction of pipe piles ?running? under self weight (198 to 625 kips in air) and pile driving hammer weight (IHC S-500 with total assembly weight of 322 kips). The term "pile running" is used to describe the penetration of the pile into the soil due to the self-weight of the pile only. This issue was critical because 1) there was limited head room under the bridge deck, and 2) if piles run too deep, the pile splicing on several piles would be problematic (the lowest desirable pile top elevation after running was +10 ft). While running measurements are sometimes made during marine/nearshore construction, there is little published data on predicted vs. actual running. This paper discusses the running prediction under self weight for 26 piles, and the methodology used in developing the predictions, which ranged from 15 to 94 ft of penetration below mudline. Pile running was recorded and compared with predicted values. The prediction methodology was quite good, and no significant constructability problems were encountered. The authors ?tweaked? the model to provide a slightly improved prediction method. The paper presents the model, predictions, observations, and discusses important lessons learned.

Jan 1, 2006

By Sitotaw Y. Fantaye

"The first segment of the Second Avenue Subway extension is approaching construction completion. The new extension will operate along Second Avenue from 96th Street to 63rd Street, where it will divert west along the existing 63rd Street line, stopping at the Lexington Avenue/63rd Street Station. The new line will have stateof-the-art stations at 96th, 86th, 72nd and 63rd streets.Most of the two-track, twin-tunnel subway was constructed using bored tunnel methods (Figure 1), with a tunnel boring machine (TBM). The launch and retrieving box of the TBM was strategically located at the south end of the 96th Street Station where bedrock exists approximately 70 ft (21.3 m) below street level. The TBM launch box and the 96th Street Station (Figure 2), including the ancillary facilities adjacent to the station, were constructed by the cut-and-cover method. The cut-and-cover work required the contractor to design and implement a stiff, tightlybraced retaining wall, approximately 100 ft (30.5 m) long, to tie the existing tunnel constructed in the 1970s to the new station, temporary street decking over the entire excavation, and a wide range of excavation support systems at various locations.The cut-and-cover construction posed significant challenges including: installation of street decking on busy Second Avenue, relocation and suspension of the myriad utilities beneath the streets, and configuration of a lateral support system that would minimize movement of adjacent structures but not slow down excavation activities. This article describes the innovative solutions developed to manage and facilitate safe and efficient construction without disrupting Second Avenue, a major southbound one-way thoroughfare.The work was performed in several phases involving: (1) preconstruction condition survey of existing buildings, (2) installation of instrumentation and monitoring, (3) major utility relocation efforts to move vital utilities from within the alignment of the slurry wall on both the east and west sides of the avenue, (4) implementation of maintenance and protection of traffic plans, (5) installation of temporary street decking across the entire avenue and over the excavation to allow an orderly movement of traffic and pedestrians, (6) staged excavation and installation of an intricate temporary bracing system beneath the decking (7) step-by-step construction of the new subway station’s structure and (8) staged removal of the bracing as the structure gained sufficient strength to resist the lateral loads. The main focus in this article is the design and construction of the temporary street decking and lateral bracing systems; the utility suspension system and the north tie-in that allowed the daunting task of excavation and construction of a new subway station in bustling New York City, with minimal disruption to the community, businesses and everyday traffic."

Jan 1, 2016

By Richard T. Stain

"In 2001, a pile trial site was established at Limelette in Belgium consisting of 25 displacement screw piles and 5 driven pre-cast piles. Interested parties were invited to participate in a pile prediction event, whereby they would submit predicted static load test behaviour in the form of load settlement plots. These predictions could be based on soil investigation results supplied by the organizers, or dynamic load test measurements.Following the submission deadline, the organisers released the results of static load tests for comparison.Of all the six participants, including Statnamic, the SIMBAT method was independently accredited with achieving the best predictions.This paper examines at the differences between SIMBAT and other systems, and presents the correlations from the Limelette trial.INTRODUCTIONThe Belgian Building Research Institute (BBRI) initiated an ambitious research programme involving the construction and testing of some 60 trial piles spread between two sites, a clay site at Sint Kateline Waver and a sandy site at the BBRI headquarters at Limelette. The project was financed largely by the Belgian Ministry of Economic affairs. (ref 1.) This paper refers only to the second site.At Limelette, six different types of displacement pile were installed: one driven pre-cast and five cast in place screw piles - Atlas, DeWaal, Fundex, Olivier and Omega. A detailed site investigation was carried out including in-situ and laboratory tests.An international pile capacity prediction event was publicised, participants being invited to predict static pile behaviour. Predictions could be based on:"

Jan 1, 2005

Jan 1, 2004