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By Ken MacLeod

A development at 83 Queens Road in Melbourne, Australia required construction of a three level basement. The normal geotechnical constraints of excavating adjacent to an existing relatively new building were challenging enough for the complicated soils profile occurring at the site. An additional significant challenge faced by the designers, was the requirement to excavate underneath the entire footprint of an existing heritage listed building, known locally as the Mansion, in the centre of the site. Maintaining the structural integrity of that building was afforded the highest priority during the 10m excavation. This paper describes geotechnical aspects of the analysis, design and construction of the secant retention system adjacent the new building and support of the Mansion enabling the 10m excavation to proceed without causing damage to the structure. The secant wall comprised hard-soft interlocking piles constructed using CFA methods. CFA piles along the length of the Mansion provided short term support, with the building load being transferred to the piles by large steel beams jacked under the building. Survey results confirmed that movements of the retaining wall and also the load bearing piles were minimal and well within design expectations.

Jan 1, 2006

By Laurel E. Blackman

The DFI Project Information Management Systems (PIMS) Committee cooperated with the US Army Corps of Engineers (USACE) to develop a specification for PIMS used on USACE projects. Once completed the Committee developed a more generic version of this specification for general use, which is contained in this document. This first edition has simply removed the USACE-related requirements from the document. The committee will continue to work on this specification to enhance the content and also incorporate recent technological development for these systems. It is the Committee's intention that a second edition will be issued in 2022.

Jan 1, 2021

By Brian Wilson, Franz-Werner Gerressen

"Cutter Soil Mixing, also known as CSM, was developed in Europe as an alternate method of Deep Mixing to the more traditional single and multiple auger techniques, and brought to market by Bauer Maschinen GmbH (Bauer), towards the end of 2003. Initial development of the technique had been completed in a joint venture between Bauer and Bachy Soletanche. In 2004 the concept was introduced to the North American market. Continued development of the method and demonstration of its versatility, both in terms of applications and applicable soil types has seen a steady growth in the number of designs incorporating the approach, and contractors offering the technique. This paper provides a brief overview of the variety and size of projects and applications where the method has been adopted, discusses some lessons learned with respect to equipment operation as well as the improvements that have been introduced to the equipment, and briefly reviews the current state of practice, as well as some of the associated on-going research and development.BACKGROUNDCutter Soil Mixing (CSM) is a technique for deep soil mixing that was initially developed as a collaborative effort between Bauer Maschinen (Bauer) and Bachy Soletanche, but which ultimately resulted in the separate development of two somewhat different brands of CSM tool. The Bauer brand of CSM entered the European market in 2004, and was first promoted in the North American market in late 2004, with the first project starting in 2005. The Bachy Soletanche brand, sometimes referred to as “Geomix” was first marketed in Europe in 2005 and the first model introduced in North America in 2007.The development of the Cutter Soil Mixing technique utilized the experiences gained from Trench Cutter/Hydrofraise equipment, developing a technique that incorporates two cutting wheels rotating about a horizontal axis as opposed to the more conventional deep soil mixing approach which utilizes augers and mixing paddles rotating about vertical axes. Whereas the Trench Cutter/Hydrofraise technique excavates the soil from within a panel, and supports the open hole using a bentonite slurry, the CSM technique cuts and displaces the soil whilst pumping a slurry/grout directly into the soil through a port located between the wheels. The combination of cutting the soil while introducing an appropriate volume of slurry effectively fluidizes the column of soil around and above the cutter head. While this process achieves a high degree of mixing, even on the downward cutting stroke, thorough in-situ mixing typically occurs on the withdrawal stroke, when most of the slurry is added."

Jan 1, 2015

By A. Bozorgzadeh, B. M. Jensen, B. N. Koelling, B. R. Murtaugh

"The Service Base mooring system originally consisted of two general types of structures, 19 timber piles cabled together and steel three-legged pipe piles. The St. Louis District fleet moored to the fleet barges which were tied off to shore-side concrete deadman and supported on the landward side by the timber and steel piles. The purpose of this project was to replace the existing floating wharf mooring system at the St. Louis Service Base. The Marine Design Center of the U.S. Corps of Engineers developed a three pile cluster system concept. The clusters consisted of one vertical pile and two batter piles. Piles in rock sockets were selected to resist the uplift loads due to high wind loads on the tall, spare lock gates stored at the floating wharf. This paper focuses on the design of the rock sockets for steel pipe piles with large uplift loads and the lessons learned during the design and construction of this system.INTRODUCTIONBackgroundThe U.S. Army Corps of Engineers’ St. Louis District is located at the critical transition point on the Mississippi River where it is a “locking river” north of St. Louis and an “open river” to the south. The St. Louis District is responsible for maintaining navigation channels on the Mississippi River, the Illinois River and the Kaskaskia River. It is also responsible for the operation and maintenance of five locks and dams within its geographic boundaries.The St. Louis District utilizes a fleet of vessels (dredges, crane barges, motor vessels, and barges) to support the navigation mission identified above. The St. Louis District Service Base, located in St. Louis, Missouri, serves as the base of operations for the district fleet. This riverfront facility originally consisted of a floating wharf, a railroad trestle, and a walkway down the river bank to the floating wharf. Historically, there have been two fleeting areas at the Service Base. The main fleeting area was approximately 965 feet long and consisted of six fleet barges (Figure 1). This area supported the Dredge Potter and its attendant fleet. The upper fleeting area was approximately 1,050 feet long and consisted of various stop log, crane and work barges, dredge pipe pontoons and work flats."

Jan 1, 2017

By Joseph A. Sopko

The first documented procedures for designing frozen earth structures are over 50 years old, implemented long before the introduction of the Finite Element Method (FEM). Since that time, the development of three-dimensional models has made the traditional and often over-conservative methods relatively obsolete. This paper discusses a new approach that is largely dependent on the analysis of internal stresses with the frozen structure and comparison to frozen soil laboratory tests. A specific design process is discussed related to initial field investigation, laboratory testing, structural and thermal analysis, and performance monitoring. The design results are compared to case histories in the field that verify the procedure. BACKGROUND One of the first documented methods to designing frozen earth retaining structures was by Sangar (1968). Methodical refinements were published by (Harris 1995) and published by the International Symposium on Ground Freezing in 2002 (Andersland et al. 1991). The structural design or thickness of the frozen mass was based on the unconfined compressive strength of the frozen soils. Two simple equations for determining the thickness of a frozen shaft are shown in Fig. 1 and the first two equations below.

Jan 1, 2019

By Hee-suk Yun, Dae-jin Hwang, Jeong-woo Seok, Myoung-mo Kim

"In this paper, the accuracy of the data measured by a newly developed displacement measuring system, DPRMs (Digital Pile Penetration and Rebound Monitoring system) and its applicability as a quality control tool were verified by field measurements of pile penetration and rebound for pile driving performed at 3 construction sites and 1 test site. The DPRMs data were found to be much better than handwork data. A new dynamic formula for pile capacities is proposed uses the results of a pilot dynamic load test and the final pile penetration. The ratios of pile capacities obtained by the new formula to those by the dynamic load test were 94%±7.4% in the contrast with 123±28.3% by the 5S formula and 68±24.0% by Hiley's formula. This result shows the superiority of the new formula. The ratios of the maximum compressive stresses calculated by using DPRMs to those calculated by using PDA (Pile Driving Analyzer) were about 90-110±10%. This result confirms the applicability of DPRMs as an overdriving monitoring tool. Two sets of DPRMs were used to measure the 3-D displacement behavior of a pile head at the test site. The more the pile head moves laterally, the less the final set values were expected because of the loss of driving energy, but this trend was not obvious within the limited data obtained at the test site.INTRODUCTIONPile construction monitoring consists of two parts. In the first part, enough capacity of the pile is secured to stand the design load. In the other part, pile damage during driving is prevented. Although several methods can be applied to achieve the first part, PDA is nearly the only tool for measuring pile stress.Several methods such as a static load test, a dynamic load test, an Osterberg cell, and numerous driving equations can determine the pile capacity. Among them, the static load test and the dynamic load test are most widely used. The static load test is advantageous because it has the highest reliability. The disadvantages are as follows: it is costly and time-consuming. Also, the capacity of the pile under construction cannot be evaluated. The dynamic load test has lower reliability than the static load test, but it is cheaper than the static load test, is reliable enough to determine the pile capacity, can evaluate the capacity of a pile during construction, and can offer information about construction conditions such as the pile integrity and the pi le stress during driving. The dynamic load test takes a relatively short time and is low cost compared with the static load test. However, it is still costly, time-consuming, and unnecessary to apply to all piles in the field as a construction measurement tool. Therefore, driving resistance (blowcounts) is commonly measured to confirm the pile capacity at construction sites."

Jan 1, 2005

By Mahesh Hingorani

Integrity issues for bored cast-in-situ piles have raised the need for the use of non-destructive tests to verify pile integrity and detect possible anomalies in installed pile sections that could adversely affect their serviceability. Integrity inspections performed after installations are often the most reasonable alternative available to assess the shaft quality. The two most common methods are pulse-echo from a small hand held hammer at the pile top, and cross-hole ultrasonic transmissions along the shaft between parallel sonic pipes. While different in technique, each method has its advantages and limitations. This paper emphasizes more on the degree of accuracy of low-strain pile integrity test by comparing the results with cross-hole sonic logging. Reliable data collection and interpretation by an experienced test engineer will reveal the integrity of the pile. Cross-hole sonic logging and low-strain pile integrity testing were both specified as quality control measures for a metro rail project in India. Both cross-hole sonic logging and low-strain pile integrity testing indicated defects in several bored piles. Also minor imperfections recorded by cross-hole sonic logging were observed in low-strain results. The observations of the two test methods are presented and compared for a better understanding of the importance of low-strain test results for any project. INTRODUCTION Cast-in-situ concrete piles are often chosen as a deep foundation alternative where challenging soil conditions exist. Although quality control measures are almost always taken during the installation of the piles, it is often difficult or impossible to confirm the integrity of the pile at this stage, particularly in wet conditions. Because of the relatively high probability of bored piles having anomalies, quality assurance of each bored pile is essential for each project.

Jan 1, 2019

By Peter Middendorp, David J. Tara, Gerald E. Verbeek, Jan Fischer

"For pile driving simulation the model used must be accurate for the entire process, i.e. from the start of pile driving until the pile has reached its target depth. Of the various model components (hammer, pile and soil), the soil is the most difficult to characterize accurately. This is well known, but the aspect that is not as well understood (and therefore commonly misapplied) is the fact that the soil properties and thus the soil parameters do not remain constant during the pile driving process. Furthermore, this phenomenon of soil fatigue, mainly for skin friction, as a continual change of soil resistance during pile installation, is not implemented into all commonly applied pile driving simulation software and could therefore not be taken into consideration. In this paper the effect of soil fatigue will be described by numerous research results, showing that this effect will occur regardless. Different methods to consider the change of soil resistance during pile installation will be presented, some applying soil fatigue while others merely reduce soil resistances. Using currently available wave equation software that can take soil fatigue into consideration, the importance of doing so will be shown on the basis of the back calculation of a monopile installed offshore in Germany.THEORY BEHIND SOIL FATIGUESkin friction and toe resistanceTo simulate pile installation as accurately as possible, detailed geotechnical knowledge about the mechanical behavior of the soil surrounding the pile is necessary during each step of the installation process. Therefore, to ensure ""geo-mechanical correctness"" of a pile driving simulation, the shaft friction and the toe resistance have to be recalculated at each penetration level. For the skin friction parameters this is especially important since they change significantly during pile installation because of soil fatigue. Depending on the pile and soil type, the toe resistance can experience changes as well due to soil fatigue during to pile driving. However, in this paper the toe resistance values were kept constant over the entire penetration depth.In general, the unit skin friction can be derived from measured values (CPT, qs) or calculated as a function of the horizontal effective stresses dh acting perpendicular to the pile wall of a vertically driven pile. The horizontal stresses can then be converted into the unit skin friction qs using the Mohr-Coulomb failure criterion:"

Jan 1, 2017

By Donald A. Bruce

"The Deep Mixing Methods (DMM), in their current forms, have been employed in the United States since 1986, although an earlier version had seen service from 1954. The earlier developments were strongly influenced by practices in the Nordic countries and Japan, while by the late 1980’s several DMM systems had been developed in the U.S. itself. Since then, DMM has continued its evolution, principally via the challenges of a series of large, landmark projects, but also via distinct, significant technological advances. This paper highlights the key points in the history of DMM in the U.S., and provides an overview of the different methods currently in use.IN THE BEGINNINGIt is a common misconception that the history of applications of the Deep Mixing Methods (DMM) in the United States dates from 1986 when SMW Seiko Inc. — a subsidiary of Japan’s Seiko Kogyo Company — was established in the Bay Area. However, the author believes that Intrusion Prepakt Co.’s patented MIP (Mixed in Place) system had been used, albeit sporadically (about 30 projects are recorded), since 1954 (FHWA 2000, 2001). Ironically, by 1961 this single auger method had been extensively used under license in Japan for excavation support and groundwater control — by the Seiko Kogyo Company. By 1972, the original MIP technique had been succeeded by more advanced Japanese methods, involving multiple augers. Intrusion Prepakt have long since become defunct.The first systematic studies of contemporary Deep Mixing Methods in Japan began in 1967 when the Port and Harbor Research Institute of the Ministry of Transportation began laboratory testing using granular and powdered lime for treating soft marine soils. Fundamental studies continued through the early 1970’s, by which time the development of industrial scale equipment was well advanced, having its first application on a marine trial near Haneda Airport. Coincidentally, laboratory and field research also began in 1967 in Sweden (“Swedish Lime Column Method”) for treating soft clays using unslaked lime. Reportedly the progenitor was a Norwegian, Kjeld Paus, who had made observations on fluid lime columns in the U.S. It would seem that developments in Japan and the Nordic countries proceeded independently until 1975 when the technology leaders from each group (Broms and Boman; and Okumura and Terashi, respectively) presented their — very similar — findings at a conference in Bangalore, India. Limited technical exchanges ensued thereafter.Whereas the Nordic developments continued to focus on the use of dry reagents (cement and lime) and relatively light equipment compatible with operating on and in very soft clays and organics, the Japanese progressed into the use of fluid reagents (cement-based grouts) and heavier equipment for both marine and land-based projects. Thus, by 1986, there were a large number of proprietary (wet and dry) DMM systems in Japan, and a rapidly growing market already by then accounting for over 12,000,000 m3 of ground treatment."

Jan 1, 2015

By Michael Perlow

Helical screw piles in use since 1838 are routinely used for energy, transportation, municipal, industrial, marine and coastal infrastructure as well as for excavation support, environmental remediation, and foundation repair. They are especially well suited for work in constrained areas, renovations and structure retrofits. Helical pile design procedures over the past 10 years have gone through a remarkable evolution with the establishment of the 2007 AC358 Helical Pile Acceptance Criteria and inclusion of helical screw piles in the 2009 International Building Code (IBC). New 2009 IBC building code requirements and AC358 Acceptance Criteria are presented along with advances in helical pile design procedures, installation, QA/QC, and recommended load test verification criteria. Use of helical smart piles to validate helical pile design and verification of ultimate pile capacity is highlighted.

Jan 1, 2011

"The Morris Island Lighthouse (MIL) is located between the jetties leading to the Charleston Harbor and Folly Beach, S.C. The present structure is the third lighthouse to occupy this location. The first navigational aid was erected in 1673, and consisted of a raised pan filled with pitch, which was set afire at night to guide early ships. The next structure was built in 1767, and constituted the first real lighthouse, standing 42 ft (12.8 m) in height. In 1838, a second lighthouse was built on the site, and it measured 102 ft (31 m) in height and featured a revolving light. This structure lasted until 1862 when Confederate troops, during the Civil War, destroyed it to deny its use to Union troops.Navigators steered these waters without a lighthouse for nearly a decade until 1876, when the current structure was built under the direction of the U.S. Army Corps of Engineers (USACE). In 1886, the Charleston area suffered a M7.6 earthquake. Significant damage was caused throughout much of the area, including a slight “list” of the lighthouse to the northeast. As a result, the cast of the beacon was reduced from 18 mi (29 km) to about 6 mi (9.7 km), causing much distress to navigators until the beacon platform was releveled and remains at this list to the present day.Conditions for ConcernThe current lighthouse was originally constructed about 1,200 ft (366 m) from the shoreline. Over the years, USACE has undertaken several programs to meet the increased shipping and navigation demands in the Charleston Harbor. Around the turn of the last century, two jetties were constructed, which drastically changed the approach direction for ships entering the harbor. In subsequent years, the harbor began to experience accelerated siltation."

Jan 1, 2017

By Jun Ohbayashi, Yoshiyuki Yagiura, Hiroaki Miyatake, Masuo Kondoh, Naotoshi Shinkawa

"Reducing the improvement ratio of ground improvement is an extremely efficient way to reduce the construction cost and construction period of mitigation measures for soft ground. The Arch Action Low Improvement Ratio Cement Column (ALiCC Method) is one method for this, and it is being increasingly applied to sites. This method enables us to rationally evaluate the embankment loads that are acting on cement improved soil columns and unimproved ground, by considering the arch action generated in the embankments and from there thusly allocate improved soil columns in spans of a greater distance than those needed for conventional methods. As a result, it serves to reduce construction costs and the construction period, while also minimizing the settling of the embankment and differential settlement, by placing numerous improved soil columns in the ground immediately beneath the embankment at equidistant intervals. In this report, we give a basic overview of the ALiCC Method, report typical construction results from real life cases that have been carried out, and make comparisons with other construction methods in order to report on the effectiveness of this design method.OVERVIEW OF ARCH ACTION LOW IMPROVEMENT RATIO CEMENT COLUMN (ALiCC) METHODIn the area of mitigation measures for soft ground, a significant role is played by ground improvements using improved materials such as cement. For this reason, a reduction in construction costs and construction period required for ground improvements has become of greater importance. The Public Works Research Institute carried out joint research with Kiso-Jiban Consultants Co. Ltd., Kitac Co. Ltd., and Fudo Tetra Co. Ltd. over a period from 1998 through 2002, and, from that, developed the ""Arch Action Low Improvement Ratio Cement Column Method"" (hereinafter referred to as the ""ALiCC Method"") that enables ground improvement with a lower improvement ratio (the improved area ratio is approx. 10% to 30%) than is required for conventional methods, while also ensuring stabilization and minimizing the settling of embankments.In the area of mitigation methods for soft ground by deep mixing, the dominant method until now has been that (50% or more of improvement ratio) shown in Fig. 1. This method comprehensively improves the area under the face of the slopes of both sides of the embankment. This is based on the calculated stability against rotational slip, which states, ""the most effective way to ensure the stabilization of the embankment environment is to carry out improvements of the area under the face of the slope."" Therefore, for the area under the face of the slope, ground improvement by deep mixing was done, and for the soft ground in the area under the middle part of the embankment, accelerated consolidation methods (hereinafter referred to as ""conventional method"") such as sand draining method and paper draining method were used. Mitigation measures that combine these improvement methods have also been mainstream for a long period of time and are used to prevent side deformation around the embankment. However, there have been some problems that have occurred, such as a situation where consolidation settling occurs in the center area under the embankment where no improvement had been carried out. This phenomenon leads to a situation in which the improved soil columns in the area under the face the of slope are pushed to the outside, which results in side deformation occurring around the area of the embankment, and additionally the occurrence of a step due to a situation of differential settlement between the improved ground and the consolidation advancing part, which results in cracks in the embankment."

Jan 1, 2015

By Christian B. Woods, Joe C. Drumheller

"Kenneth A. Huber, P.E., Langan Engineering & Environmental Services, New York, New York, USAThe dream to bring New Jersey Devils hockey to the largest city in New Jersey became a reality in the summer of 2005, when construction began for the Prudential Center in downtown Newark. The Prudential Center site encompasses an entire city block that had a varied history of uses ranging from a cemetery in the late 18th century, to a rail yard and train station for the now-defunct Central Jersey Rail Road in the 19th and early 20th centuries, to commercial development in the latter half of the 20th century. Each of these prior uses presented challenges to the design and construction of the Prudential Center that required innovative engineering solutions, including: archaeological investigation and exhumation of the former cemetery occupants, protection of historic buildings surrounding the site, and extensive demolition to remove old train bridge foundations.The design team was required to develop potential foundation systems for the arena. Several foundation concepts were evaluated for cost and constructability, including: driven piles, drilled shafts, and shallow foundations on improved subgrade. Following a detailed cost analysis and value engineering exercise, the decision was made to support the arena on spread footings following the completion of a multi-phased ground improvement program consisting of a combination of dynamic compaction and removal and replacement. To evaluate achievable allowable bearing pressure as part of the design, a dynamic compaction test section was performed within the building footprint prior to the start of production work; this resulted in an increase of the allowable design bearing pressure from 2 tons per square foot (tsf) to 3 tsf. This reduced the expected foundation costs by 30% and gained sufficient time in the schedule to allow for the completion of the arena in time for the New Jersey Devils 2007- 2008 hockey season.BACKGROUNDThe dream to bring New Jersey Devils hockey to the largest city in New Jersey became a reality in the summer of 2005, when construction began for the Prudential Center in downtown Newark. After several years of negotiating between the City of Newark, local landowners, area developers, and the Devils themselves, a deal was finally struck to erect Newark Arena, now known as the Prudential Center, right next to City Hall. This is not to say, however, that once the site location was finalized, that no further challenges were encountered in the construction of Newark’s new crown jewel."

Jan 1, 2015

By Randy R. Williams, Brian W. Wilson, George M. Filz, Marina S. W. Li

"Detailed design of an extensive deep mixing (DM) scheme using the Cutter Soil Mixing (CSM) technique was completed for foundation support of mechanically stabilized earth (MSE) walls for Kitimat Liquefied Natural Gas (LNG) at Bish Cove, British Columbia, Canada. The design was based on the provision of soil-cement structures, constructed in highly variable subsurface conditions that consisted of thick deposits of fine-grained soils overlying granular soils, and required to meet project-specific performance criteria, to support the MSE walls. The design, consisting of rectangular CSM panels constructed to form barrettes connecting to a longitudinal wall of continuous CSM panels, was configured to manage the distribution of stresses and strains that could be developed within the soil-cement structure.The results from 2D finite element analyses were used to determine the necessary arrangement and properties of the CSM panels to accommodate localized areas of relatively high shear, tensile and compressive stresses within the soil-cement structure. The relationships between unconfined compressive strength and elastic modulus for fine-grained and granular soil-cement structures obtained from the Bish Cove data were compared with published references and were found to be significantly different in the higher strength range materials.BACKGROUNDDeep Mixing design was completed for the development of the Kitimat LNG Facility located in Bish Cove, British Columbia, for support of two relatively high MSE walls and associated bulk earthwork operations. Deep mixing was necessary to treat the very weak native deposits in-situ to meet project performance requirements and physical constraints without the need for significant excavation and disposal work. The DM design was undertaken on the basis of adoption of the CSM technique for in-situ ground improvement of the native foundation soils which consisted of very soft to soft fine-grained marine deposits and loose to compact sandy silt to silty sand, overlying dense sand and gravel (Fig. 1). The DM area is located immediately upslope of the Bish Cove beach area, and is “L” shaped in plan, approximately 300 m long by approximately 28.8 m wide (parallel to the beach area) and 165 m long by an average width of 21.0 m (perpendicular to the beach area). The depth of the DM ranged from about 5.0 m to 30.7 m with typically 2.0 m embedment into dense granular soils. Details of the design philosophy, including an overview of the DM design and the project background information are presented by Li et al. (2014a). Details of the construction aspects of the Kitimat LNG deep mixing are presented by Wilson et al. (2014)."

Jan 1, 2015

By Chaz Weaver, James Sheahan, Michael Mo

"The Virginia Department of Transportation (VDOT) undertook a program to replace four bridges along approximately 4 mi (6.4 km) of US 340 in Northwest Virginia. Two of these bridges, which span Compton Creek and the Norfolk Southern Railroad respectively, are the subject of this article. HDR provided roadway and structural design as well as geotechnical engineering services for the Norfolk Southern Railroad Bridge while their subconsultant, Saeed Associates, provided structural engineering services in support of the HDR roadway and geotechnical team for the Compton Creek Bridge.The project is located in the Valley and Ridge Geologic Province of Virginia, on an alignment that is adjacent to the Shenandoah River. The project lies within the Beekmantown Group consisting of limestone and dolostone that are prevalent and prone to karstic activity in a band that passes through the project area and north into Central and Eastern Pennsylvania. This area has been impacted by karst limestone conditions where caves and sinkhole activity is common. Caves at Luray and Front Royal, located to the south and north of the project, respectively, are popular public attractions.Since the potential for variability of subsurface conditions can be, and often is, greater in karst terrain, the need to develop a design that provides as much flexibility as possible during construction, and then to be prepared to efficiently review and respond to construction questions is heightened. Coordination and communication among the design staff, VDOT’s design and construction staff, and the contractor was a key factor in completion of this project.Compton Creek BridgeThe alignment for the new Compton Creek Bridge is located about 125 ft (38 m) west of the existing bridge, placing it between that bridge and the existing Norfolk Southern Railroad Bridge. No information about the foundations was available for the existing bridges. Borings in the Compton Creek valley encountered extensive voids (some clay filled and some open) with numerous boulders, rock ledges and pinnacles, particularly on the north side of the creek. Geophysical and geotechnical investigations indicated that below a poor and variable upper zone of rock was a layer of more competent and consistent limestone, which appeared to contain little or no voids."

Jan 1, 2017

By Challa Venkata Rami Reddy, Anindya Roy, G. R. Konni

This paper presents the results of pile lateral capacities obtained from both conventional design and fullscale pile lateral load tests. Conventional design using P-Y curve analysis is very commonly being used by designers; designers use well accepted software programs like Lpile and Allpile for analysis. However, these programs do not cover the soil models to simulate engineering behavior of marine carbonate sands; which generally have different engineering behavior than silica/quarts sands. In this study, the existing soil models for common sands have been used to assess pile lateral capacities and these results are compared with the results from full-scale instrumented pile lateral load tests performed in compacted marine carbonate sand fills of artificial island constructed for oil and gas facilities in Abu Dhabi. The objective of this study was to verify the applicability of the existing sand soil models for carbonate sands and also to verify the associated conservatism in the pile lateral capacities. This study shows that the actual pile lateral response is much stiffer than what was anticipated through the LPile analysis. Therefore, further research focus may be required to capture the engineering behavior of the marine carbonate sands to develop specific P-Y curves.

Sep 8, 2021

By Giulia M. B., Ferruccio Cribari, Alessandro Bertero, Eliano Romani, Roberto Sorge, Francesca Casini

"The use of Artificial Ground Freezing (AGF) to form earth support and seepage control barrier systems has had applications worldwide. These cover a variety of construction problems, including the formation of frozen earth walls to support deep excavations, structural underpinning for foundation improvement, and temporary control of ground water in construction processes. An application of AGF during construction of Line C of Rome underground is described in detail.The new line “C” of San Giovanni metro station was constructed adjacent to the existing line “A” of San Giovanni station; the new metro line “C” is deeper than line “A” and runs below the existing station. The underpass project envisages an Artificial Ground Freezing in order to create a structural and waterproof temporary cut-off suitable to the two new tunnels excavation, while keeping trains running in the safest possible condition. The excavation of tunnels under the water table, with a hydraulic head of over 10 m in not homogeneous soils having different mechanical properties and permeability and below existing sensitive structures, involves special ground freezing sequences and methods, as well as peculiar drilling systems and operations, such as TDDT (Trevi Directional Drilling Technology).Artifical Ground Freezing IntroductionNatural freezing occurs seasonally in many areas of the globe and can affect negatively the engineering performance of geotechnical structures; on the other hand, man-made freezing is a controllable process that can be used by civil engineers to stabilise temporarily the ground in order to support and/or exclude groundwater from an excavation until the final retaining and lining structures are constructed. Freezing and thawing of the pore fluid within soils involve complex thermal, hydraulic and mechanical processes that have significant mutual interactions. For example, phase changes of the pore fluid caused by temperature variations can modify the pore water pressure in the soil, which, in turn, can induce mechanical deformation. At the same time, any changes in the hydraulic and mechanical conditions affect the thermal processes by advection and changes of ice and water contents.An application of AGF which will be presented in the paper, refers to the construction works of Line C of Rome underground. In this case AGF was carried out to provide temporary support during excavation of the two Line C running tunnels directly underneath the existing S. Giovanni station of Line A, in the safest possible condition. In order to keep the trains of Line A operational during excavation, a temporary structure was installed and a real-time monitoring system was conceived in order to control the temperatures of the soil during freezing and the response of the structures of the existing station."

Jan 1, 2016

By Michel Bustamante

The Arbre viaduct, 200 metres long, is the most important structure on the Belgian portion of the High Speed Train line between Paris and Brussels. The particular geotechnical conditions of the soil with carboniferous limestone affected by karstic phenomena, has prompted the designer to found the viaduct on systems of high capacity vertical and batter micropiles. The design of the working micropiles was validated by full scale tests performed on instrumented micropiles. The size of the structure and the deformation criteria to be met when HS trains are crossing the viaduct, together with the lack of references for such innovative structure, called for monitoring the movements of the piers as soon as the link was open to traffic. The authors report on the results of loading tests on micropiles and the results of settlement structure monitoring for a period of 4 years. Settlement of the foundation is estimated taking into account the group effect.

Jan 1, 2002

By J. P. Burland

The paper describes a number of recent case histories in the United Kingdom where field instrumentation and measurements have played a major role in the design and construction of excavations, piles and foundations. It is shown that the design and construction procedures for deep excavations in London Clay are based almost entirely on the results of field measurements. Examples are given of successful application of such measurements. The present understanding of the behaviour of bored piles in stiff clays and their design is based on a number of instrumented pile loading tests. The results of these tests have led to a radically new concept of pile design in which the piles operate at their full shaft capacity under working loads thereby resulting in considerable savings in design and construction. Some examples of the successful application of this concept are given. Finally it is shown that the present knowledge of the stiffness properties of chalk is based entirely on field observations. An example is given of how direct field measurements were used to solve a foundation problem at the base of a coffer-dam in chalk.

Jan 1, 2010

By George Burnhart

"Sonic drilling is a relatively new technology even though it has been in development since the late 1940s. It was initially funded by the U.S. petroleum industry and then, in the late 40s, Russian scientists worked on developing sonic drilling, their interest based on drilling rates 3 to 20 times that of conventional methods. In the early 1960s, the Shell Oil Company backed research that resulted in a down-hole device with a series of eccentric weights driven by drilling fluid to generate vibration. Hawker Sidley, in the early 1980s, developed the first modern prototype sonic drills in Vancouver B.C. and the North Star Drilling Company in Minnesota became the first contractor in the U.S. to operate sonic equipment in 1985. In 1994, North Star became a division of Boart Longyear, headquartered in Salt Lake City, Utah.What’s Unique about a Sonic DrillA sonic drill rig appears and operates very much like any conventional top-drive rotary rig. The key difference is that a sonic drill has a specially designed hydraulically powered drill head, containing oscillators, that generates adjustable high-frequency vibratory forces. The sonic head is attached directly to the drill pipe or outer casing, sending the high frequency vibrations down through the drill steel to the face of the drill bit. This creates displacement, fracturing or shearing action depending on the material being drilled. The oscillator uses two eccentric, counter-rotating balance weights or rollers that are timed to direct 100% of the vibration at 0 degrees and 180 degrees. An air spring houses the oscillators and separates the vibration from the drill rig itself. The vibratory frequency is controlled to suit operating conditions and to achieve optimum drilling rates.When the vibrations coincide with the natural resonant frequency of the steel drill rod or casing, a natural phenomenon called “resonance” occurs. It allows the rig to transfer timed vibratory energy into the top of the drill string, utilizing the natural stored energy of the steel. This causes the drill string to use inertia and act like a flywheel delivering tremendous amounts of energy directly to the bit face. In friendly overburden formations, a sonic drill rig can achieve penetration rates of one ft per second."

Jan 1, 2008