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By Frank Haehnig, Harald Krenn, Harm-Christoph Claassen

"The Wadi Dayqah Dam Water Supply Scheme represents one of the most important projects implemented by the Sultanate of Oman to ensure sustainability of water resources. The principal components of the project comprise two dams to impound the Wadi Dayqah, to store and supply drinking water to the local area and to Muscat, the capital city of the Sultanate.The Main Dam with a central spillway is a RCC Gravity Dam with a maximum height above foundations of 75m, crest length 400m; the Saddle Dam is a rockfill dam with central clay core, max height above foundations is 49m and crest length 360m. During construction of the Saddle Dam a key trench was excavated to 10m depth and filled with compacted clay connected to the central core of the embankment. Grouting utilizing cement grout was performed as a single line grout curtain prior to each filling operations. Both Dams are founded on soft Siltstone, Claystone, Sandstone and inter-bedded harder limestone.After construction of the Saddle Dam, once water was in the reservoir it became evident in early 2010 that some seepage was occurring apparently from the right abutment. This seepage became more marked when the reservoir first filled to discharge over the spillway in June 2010. In order to reduce the seepage, additional sealing works by drilling and grouting of a three row curtain up to 80 meter target depth were initiated to supplement the existing single row curtain. Part of this project for the sealing works has also been to drill additional investigation holes to provide more information and confirm extend of the additional sealing works and its limits.Züblin Ground Engineering was awarded the Additional Sealing Works Contract. Whilst Equipment was on Site, the opportunity was taken to carry out drilling and grouting on the Left Abutment of the Main Dam to reduce seepage through that abutment and to install additional standpipe piezometer for future monitoring of seepage patterns.Work on this Contract started on site in January 2013 and was substantially completed in January 2015.At the time of Tender Züblin Ground Engineering propose and Alternative Design in the form of a Secant PileCut-Off Wall, 85m long to a depth of 40m with additional drilling and grouting below the foot of the cut-off which was then included in the contractual scope."

Jan 1, 2016

By Max Gwynn, Tony Suckling

"The new Wembley Stadium is the most spectacular soccer stadium in the world, built to the highest specifications, using the latest technology and offering visitors an unrivalled match-day experience. Wembley Stadium is the home of English soccer, dating back to 1918 when the British Government began planning a British Empire Exhibition with a stadium as its centrepiece. The Empire Stadium, as it was originally known, was completed in 1924 in just 300 days and cost £750,000 ($1.4m). It was finally closed in 2000.The new Wembley Stadium, which opened in 2006, features fully covered seats for 90,000 fans and a striking arch that sits above the northern half of the stadium. With a span of 315 m (1040 ft), the 133-m (440-ft) tall arch is the longest single-span roof structure in the world. It supports the entire weight of the northern roof and 60% of the weight of the southern retractable roof. This means there is no need for columns within the stadium and ensures unobstructed views.Multiplex Constructions (UK) Ltd. employed Stent Foundations Limited to construct the £10m ($19m) foundations package for the new stadium. The scope of works for the foundation package included the design and construction of all foundations, including all main works piling, temporary works piles for the arch and roof, and tower crane piles. The scope also included trial piling and pile testing, setting out and removal of spoil.Piles were constructed by using bored cast-in-place techniques with both hydraulic and traditional crane-mounted rigs. Stent also installed sheet-piled walls at three locations to the site’s northern boundary. In addition to the main contract works, Stent constructed a £2m ($3.8m) contiguous bored-pile retaining wall within the demolition and earthworks package (Figure 1). This work was carried out as a subcontractor to Griffith McGee."

Jan 1, 2008

By Tony Amis, Marco Barla, Alice Di Donna

"Energy geostructures are becoming an increasingly popular solution around the world for Developers looking to reduce CO2 and system running costs. Energy geostructures are geotechnical structures that provide both the important role of structural stability while also acting as a heat exchanger with the ground, enabling the supported buildings and or infrastructure to be heated and cooled using the principle of low enthalpy geothermal systems. The main advantage of this innovative technology with respect to standard geothermal plant is the reduction of the initial installation costs and construction schedule benefits, compared to installing conventional geothermal solutions, largely due to the additional use of structures which would be constructed in any case. However, it is important with respect to energy geostructures that additional aspects need careful consideration. For this very reason, several research studies have been carried out over the last decade on this subject and a number of real case studies have been monitored and analysed. The key difference with respect to conventional shallow geothermal systems are mainly related to the geometry, which is imposed by the geotechnical project, and the need to ensure that the primary structural role is always guaranteed. Special boundary conditions, the reduced depth, the influence of atmospheric external temperature can also play an important role for energy geostructures. They can affect, both energy efficiency and, the geotechnical behaviour because of the possible thermal induced mechanical effects. This paper presents a picture of the current situation regarding energy geostructures and their peculiar features, and collects available data to provide a reference framework. Data has been collected from literature and personal communications and then processed to provide easy-to-read charts useful for practical consultation at a glance. This paper provides, an indication of the distribution of such systems worldwide, their spread in time, and a global view of their actual efficiency from the structural, energy, economic and environmental point of view.1. IntroductionEnergy geostructures are becoming an increasingly popular consideration around the world. Energy geostructures are geotechnical structures with a dual role of providing structural stability and the ability to exchange heat with the ground, to provide low carbon heat and coolth to supporting and or adjacent buildings and infrastructure, using the principle of low enthalpy geothermal systems (Barla and Di Donna, 2016; Laloui and Di Donna, 2013). A closed circuit of high density polyethylene (HDPE) pipes is embedded in the concrete, and a heat carrier fluid circulates through them exchanging heat with the ground. The HDPE pipework circuit inside the geostructure is linked to one of the above buildings or infrastructure through a heat pump, which adapts the temperature of the circulating fluid to the heating (winter mode) and cooling (summer mode) needs. In this way, heat can be injected into the ground during summer and extracted from it during winter. In principle, all structures in contact with the ground can be used as energy geostructures. The first examples of energy geostructures date back to the eighties in Austria and were mainly piles and shallow foundations. A decade later, Henderson et al. (1999) reported on what would appear to be the first successful use of geothermal energy piles in the US, with loops incorporated into the foundation for a hotel in Geneva, New York. As was their use in this New York case history, the typical geothermal energy pile application is used in conjunction with additional closed loop boreholes to provide the required energy capacity for a structure. Interestingly the report concludes that the geothermal energy piles had a better heat transfer performance than the borehole field. The first energy walls appeared slightly later, while still today only a few experimental cas"

Jan 1, 2017

By Jr. D'Angelo, Michael M. Blendy, Shawn Downey

"A grouted helical pile was used to support new buildings in the reconstruction of a large residential development. Foundation options were complicated by urban fill underlain with variable alluvial soil. A driven timber pile and grade beam system was recommended to support the new buildings. Other foundation options are also discussed. The grouted helical pile was quoted as an alternate and ultimately won the bid based on the economics and performance of the system. Data from 8 load tests was used to develop an empirical site specific relationship for determining pile capacity based on both installing torque and installation depth. Design to incorporate tolerance on installed pile location is presented. With the three phases completed, 554 residential dwelling units supported by 3645 grouted helical piles had been constructed covering 18 city blocks on the 44 acre site. IntroductionThe Philadelphia Housing Authority reconstructed the Tasker Homes housing complex located in southern Philadelphia, Pennsylvania, adjacent to the Schuylkill Expressway in the Grays Ferry area. Keating Building Corp. and Pennoni Associates were the general contractor and the structural engineer respectively. The original Tasker Homes development was constructed from 1940 to 1941 and consisted of 44 acres of primarily two and three-story residential brick buildings. These buildings were supported by a timber pile foundation system. The structural condition of the buildings supported on the timber piles was generally good in comparison to areas outside the buildings. These areas had settled possibly up to 2-feet in places due to the heterogeneous nature of the urban fill."

Jan 1, 2005

By Shawna Munn, Sarah Speir

Cedarvale Station is one of 25 new Eglinton Crosstown light rail transit (ECLRT) stations along Eglinton Avenue in Toronto. It is an interchange station with the existing Toronto Transit Com- mission (TTC) University subway line and is located at the intersection of two major thoroughfares. The new LRT tunnels run below the existing Yonge Spadina subway line and required total excavation depths of 20 m (65 ft) to facili- tate construction of the new station.

Jan 1, 2023

By Juan M. Pestana-Nascimento, Robert G. Bea, Hamed Hamedifar, Emery M. Roe

The current State-of-the-Practice is grounded heavily on deterministic characterization and assessment of the performance of civil engineering infrastructure. In particular, flood defense systems, such as levees, have been evaluated within the context of the Factor-of-Safety where the computed capacity of the system is compared with the code specified demand forces. Uncertainties associated with the capacity and demand forces render deterministic modeling incomplete. In particular, two structures with the same Factor of Safety can have vastly different probabilities of failure. While efforts have been made to assess levee vulnerability, results from traditional engineering approaches omit important factors because they do not account for uncertainties included in analytical modeling, and natural variabilities, or human and organization factors. This paper utilizes risk assessment methods to advance methods for quantifying the contribution of uncertainties to engineering analyses, and thereby provide additional information to help assess sustainability of geotechnically engineered systems. The probability of failure of a geotechnically engineered system is directly impacted by how well the system is understood, and how uncertainties are incorporated in development of understanding of the system. This paper presents methods to evaluate two types of uncertainties for three potential failure modes of flood protection levees: underseepage, slope (or levee) instability, and overtopping/erosion. These analyses account for two types of uncertainty: 1) Type I – inherent uncertainty, 2) Type II – analytical modeling uncertainty. Human and organizational task performance and information development and utilization uncertainties are not included in these analyses. This paper focuses on the behavior of the flood protection levee system for Sherman Island, a western island in California’s Delta. Sherman Island is of critical importance to California because of the very important infrastructure systems that pass under, on, over, and adjacent to Sherman Island, including: natural gas pipelines, regional and interregional electricity transmission lines and telecommunication facilities, two deepwater shipping channels; and State Highway 160, a link between major transportation expressways. The work evaluates current (year 2010) and future conditions (year 2100) and incorporates variations in capacity and demand arising from projected human response activities and global climate change.

Jan 1, 2017

By John E. Lens

Driving bridge foundation piles into glacio-fluvial sands and gravels and glacial tills brought surprisingly longer than predicted driving lengths on several recent projects in Vermont. In some instances, piles drove more than 40 feet past refusal depths predicted from Standard Penetration Resistances from borings terminating in glacial till. Overall, piles developed substantially less skin friction than predicted using common capacity formulas and drove as much as 80 feet longer than predicted in the moderate to dense gravelly and cobbly soils. These piles were driven for one to five span highway bridges within narrow valleys with bedrock ranging from 80 to over 200 feet deep. Piles were for both conventional and integral abutment bridges. H-piles were used for a variety of reasons including lower unit cost, better availability, and better ability to drive through cobbly soils in upper strata. Dynamic testing was used to evaluate capacity, including skin friction and end bearing capacity. In order to develop better pile length and capacity predictions for future projects, VTrans and one of their geotechnical consultants are collaborating to develop criteria for improved pile capacity predictions in these river valleys. We are doing this by evaluating driving and dynamic testing data from four projects in comparison with the Federal Highway Administration (FHWA) DRIVEN pile design software, and methods from Myerhof (1976) and Tomlinson (1981). Our overall objective is to provide a basis for choosing appropriate pile types and reliably estimating pile lengths for projects in this terrain. Bridge foundation design projects in other mountainous terrain share similar design and construction challenges to those encountered in these Vermont projects. These include: difficult exploration drill rig access requiring smaller rigs with limited capability to drill through cobbles and boulders deep enough to reach bedrock; limited experience with displacement piles as alternatives to H-piles in this geology; and relatively greater variability in soil stratigraphy between foundations at these sites as a consequence of the relatively high energy depositional environment in mountainous terrain. This paper presents the case history summaries of the pile driving, results of the ?back analysis? capacity evaluations, examples of solutions employed on these projects to address the lower capacities achieved, and resulting pile capacity design guidelines and prediction criteria for these geologic conditions based on data from these projects.

Jan 1, 2007

By R. K. Filip

"Steel bearing piles have long been used to carry high compressive, tensile and lateral loads. Such piles are most commonly tubular or ""H"" profile and are typically installed using percussive techniques. The noise and vibration associated with such installation techniques tends to preclude the use of steel bearing piles in urban and other sensitive areas.This paper describes the design and construction of an innovative new road bridge in Milton Keynes, UK. The steel bearing piles were required to continue out of the ground to form the bridge columns and abutments and then be cast directly into the soffit of the reinforced concrete bridge deck. This project was to be the first time in the UK, that this form of bridge design had been used.The paper shows how new installation techniques allowed the designers to use these high capacity steel elements in a sensitive urban environment without the use of percussive or vibratory installation techniques. Finally the paper shows how these quiet and vibration-less installation techniques can be extended to other applications.A UNIQUE BRIDGE SUPPORTED ON ""BOXED SHEET PILES""CONCEPT HISTORYThere are over 700 bridges in Milton Keynes. Concrete is the dominant construction material, most are single span with massive parallel wing wall retaining abutments. All have a certain uniformity of aesthetic design. Pell Frischmann Consultants Ltd (PFC) proposed to the client, English Partnerships (EP), that an ""integral bridge"" with a slender open appearance would be an appropriate aesthetic form for a new highways bridge, within the district of Westcroft (figure 1). The concept required that the bearing piles be continued up out of the ground to form the bridge columns and abutments. Four rows with four piles in each row were suggested. Each would then be cast directly into the reinforced concrete bridge deck forming a moment connection (figure 2). This concept meant that a single continuous steel structural member would replace traditional reinforced concrete bored piles, pile caps and piers. This member would carry vertical and lateral loads. The conceptual design was intended to meet the following client requirements:"

Jan 1, 2005

By Ana Pereira, Naomi Norris, Donald Bruggers

The city of Christchurch, New Zealand is predominantly founded on alluvial sediments consisting of interbedded layers of loose to medium dense sand, soft to stiff silt and clay mixtures, and pockets of organics. These soil deposits have high liquefaction potential. Following the 2010/2011 Canterbury Earthquake Sequence several ground improvement trials were undertaken within Christchurch to understand the effectiveness of different types of ground improvement in these silty sand geological conditions. This paper presents a discussion of a stone column ground improvement trial undertaken at a Christchurch site with high fines content soils. Stone columns were installed using two types of installation methods and a range of Area Replacement Ratios (ARR) to assess the effectiveness of these ground improvement methods in high fines content soils as well as the influence on the type of installation method. Pre- and post-column installation CPTs, seismic Dilatometer Tests (sDMTs), cross-hole shear wave velocity tests, and plate load tests have been undertaken to assess the effectiveness of the ground improvement. Results of the testing are presented in this paper. INTRODUCTION This paper presents the results of a stone column ground improvement trial undertaken in Christchurch, New Zealand (Fig.1). In 2010 and 2011, four large earthquakes (greater than magnitude 5.9) and thousands of smaller aftershocks occurred in the greater Christchurch region. These events are referred to as the Canterbury Earthquake Sequence (CES). Liquefaction occurred across large portions of the city during the stronger earthquakes, particularly the February 2011 event. Following the CES a large amount of data was collected across the city including the location and volume of sand boils, and the location and magnitude of ground cracks. Additionally, data from thousands of ground investigations have been uploaded into a public database. As a result, there is clear evidence that silt and silty sands liquefy in addition clean sands. The CES and resulting liquefaction motivated a series of studies and trials from different organisations aiming to better understand the available technologies for liquefaction mitigation. The subject of this paper is a ground improvement trial undertaken by a local contractor specialising in deep foundations and ground improvement. They were interested in understanding the effectiveness of stone column ground improvement in high fines content (silty) soils using two different installation techniques, vibratory and non-vibratory. Different arrays and Area Replacement Ratios (ARRs) were used for each of the two methods of columns installation.

Jan 1, 2019

By Masakazu Takano, Koji Suzuki, Naotoshi Shinkawa

"Cement deep mixing (CDM) method successfully applied to a marine construction project in northern Vietnam is reported. The method is classified as wet method, in which cement slurry is injected into the ground. Thickness of clayey deposit subjected to improvement is from 20 m to 28 m, and the total volume of CDM improvement exceeds 460,000 m3. This is the first massive application of CDM method in the region. Three CDM barges, each equipped with four mixing shafts, were brought to the site in order to finish CDM work within a period of seven months. Cement content used in the work was 180 kg/m3 and water-cement ratio of slurry was 100%. Unconfined compression strength of stabilized soil was 1,200 kPa to 1,600 kPa in average with coefficient of variation from 0.3 to 0.4. Statistics analysis of the strength with these values gave percentage of lower strength less than 10%. Trial use of needle penetration test performed to study strength profile of a CDM column is also reported.INTRODUCTIONThe site of Lack Huyen Port Infrastructure Construction Project is located in the sea adjacent to Cat Hai Island, offshore Hai Phong city which is around 100 km east of Hanoi, the capital of Vietnam. Left side of Fig. 1 shows the location of the site. The project contains development of container terminal, dredging of waterway, construction of sand protection dyke to prevent waterway from being buried, and bridge construction to connect the island to the mainland.Joint venture of Penta Ocean Construction and Toa Corporation was awarded Package 6 of the project, in which reclamation of container terminal area, retaining wall construction and terminal road construction were included. Plan of the site is presented in right side of Fig. 1. The site work has been started in June 2013 and is scheduled to finish within 4 years."

Jan 1, 2015

By Hyunsuk Yoon, Kiho Lee, Juhyng Lee, Younghoon Jung, Junboum Park

"The environmental double pile method is presented as a device to improve the engineering properties and to clean up contamination of low-permeability soil. This method is one of the novel technologies based on the concept of one step process. It can be applied to low permeable contaminated ground for site reuse. It uses piles to improve drainage, contaminant remediation, and bearing capacity of the ground. To evaluate the on-site applicability of this technology, drainage and strength properties of the environmental double pile were assessed by a series of experiments and numerical analysis. Environmental double pile was found to be a feasible alternative method to improve contaminated soft ground.Korea is a peninsula with many coastal industrial zones. These zones are located in regions mostly underlain by soft ground with low permeability and adjacent to industrial areas that can be contaminated. Therefore, a new region-specific remediation method is required to achieve environmentally sustainable development. This research introduces the Environmental Double Pile (hereinafter, refer to as EDP) for the lowpermeability contaminated ground and focused on both contaminant remediation and soft ground improvement. Basically, the EDP is quite similar to sand compaction pile (SCP). The SCP has been studied extensively to improve soft ground (Braja 1999; Hansbo 1994; Madhav and others 1978; Taylor 1948). But unlike SCP, EDP is filled with oyster shells instead of sand and an inner pile is inserted in the center of this oyster shell filled-zone. Therefore, it is a double pile consisting of the oyster shell pile and the inner pile, as depicted in Fig. 1."

Jan 1, 2005

By Abolfazl Eslami, Sara Heidarie Golafzani

CPT-based methods considered as complementary tools for static analyses outperform other axial pile bearing capacity predictive methods. Considering soil spatial variability and minor errors associated with procedure and operator, CPT-base methods mitigate the effect of latent uncertainties in pile design. These methods were developed based on different databases and purposes. Hence, several statistical and probabilistic attributes were defined and implemented to assess the predictive CPT-based methods’ performance via CPT and pile databases in terms of the model parameter. These features make a comparison among methods in terms of precision, accuracy, and efficiency. Furthermore, CPT-based methods can be subjected to scrutiny over their backgrounds and how they were developed via reliability analysis. In this regard, a database of sixty-two driven piles and their adjacent CPT soundings were gathered, and six commonly applied CPT-based methods were examined according to criteria other than prevailing statistical and probabilistic ones, including; (a) input variables, (b) soil behavior classification (SBC) (c) model assumption (d) Influence zone, and (e) axial loading direction. According to these introduced criteria, CPTbased methods were classified and appraised via efficiency ratio. Eventually, these reliability-based, statistical, and probabilistic criteria evaluate the understudied methods performance for the investigated compiled database and help designers select consciously appropriate predictive methods according to the site conditions.

Sep 8, 2021

By John A. Egan, Nathaniel Wagner, Micaela Largent, Jonathan P. Stewart, Debra Murphy, Jeremy Butkovich

The Millennium Tower is a 58-story reinforced concrete building that was constructed in San Francisco, California between 2005 and 2009. The Tower is founded on an embedded pile supported mat with pile tips bearing in dense marine deposits that overlie an over-consolidated marine clay layer known locally as Old Bay Clay. This clay layer experienced stress increases from Tower self-weight and from multiple episodes of de-watering between 2006 and 2018 at the Tower site and neighboring sites. Settlements of the Tower foundation have been measured since 2006 and lateral deflections of the Tower have been inferred and measured since 2009. Available information on this case history include geotechnical site conditions and data from a monitoring program that tracked foundation settlements, Tower tilt, groundwater levels at the Tower site, and ground inclinations over time. This presentation will discuss the ground deformation mechanisms that caused the observed movements, the degree to which the movements can be predicted, and lessons from this case history for the design of deep foundations for tall buildings in San Francisco and geologically similar regions.

Sep 8, 2021

By Glen Mann, H. G. Vestberg, Robert D. Holtz

"Underpinning of residential and commercial structures is often accomplished using a number of driven-in-place small diameter steel pipe piles. These piles, at least in the Seattle area, are typically described as pin-piles and are driven with an air compressor operated jack hammer to a refusal criterion developed from an empirical basis. Over the past twenty years or so, the materials have improved in quality and strength, and the driving equipment has improved in efficiency and capability. These improvements have resulted in damage to the pin-piles during driving as well as to the driving equipment. The primary objectives of this load testing study were to develop a relationship between the driving penetration resistance of 2-inch diameter pin-piles and the ultimate bearing capacity when piles were driven at different penetration rates and, based on the load test results, to develop an opinion regarding an increase in the allowable axial load capacity [ultimate load capacity divided by a factor of safety] of a 2-inch diameter pin-pile over the currently used permissible load capacity of 4 kips in the Seattle area. Also, if feasible, a reduction in the present driving penetration rate was to be recommended to help reduce the rate and magnitude of pile and equipment damage whilst maintaining the allowable load capacity. The recorded ultimate bearing capacities were also compared with the Tagnent-line and the Davisson analytical methods in an effort to determine if either of these provided a reasonable determination of the pile load capacity.IntroductionThis paper describes the results of a series of load tests performed on small diameter, 2-inch, driven-in-place steel pin (pipe) piles and based on these results, provides the support for a modification to the presently used allowable axial pin-pile capacities.The intent of the load testing program was to determine how much influence the penetration resistance might have on the individual piles' ability to support the allowable axial load without undergoing any significant vertical deformation. For the purposes of this paper the ""allowable load capacity"" is considered to be the ultimate pile load capacity divided by a minimum factor of safety, typically considered to be 2.0 in this area. A pin (pipe) pile comprises an open or closed ended, schedule 80 steel tube which is driven-in-place, usually with an air compressor operated 90 pound pneumatic jack hammer. These jack hammers typically operate at a rate of about 1,200 blows per minute, (Haggard, Holtz and Mann, 2001 )."

Jan 1, 2005

By Huw Williams

"Power companies are always looking to increase the carrying capacity of existing transmission lines, and the preferred method is to string heavier capacity conductor lines. However this results in higher wind loading and the potential for towers overturning, if the existing foundations do not have the tensile capacity. On older lines, there is often a lack of information on construction type and dimensions and in practice the as-built foundation can differ considerably from design drawings, due to unforeseen ground conditions along the line route, and no record of the resulting change in design being made.Following successful trials in New Zealand, integrity testing with Frequency Response and impedance profiling techniques is now being used in the region to check concrete foundation properties in-situ and are enabling power companies to get the most out of their assets. INTRODUCTIONIn most regions of the globe, the US included, there is generally a requirement to upgrade transmission line capacities, to cope with increasing power consumption. Problems with under capacity only come to light for the public when blackouts occur, even in developed countries.A large number of transmission line towers are designed with a certain capacity redundancy and will be able to carry greater loads than originally designed for. Power companies are therefore looking for ways to assess their assets and to minimize the costs of upgrade work.Re-assessment of tower foundation capacities using design drawings may not be valid , as constructed foundations may differ considerably from design drawings, to accommodate local difficulties and in some instanced, particularly with earlier lines, there is no information whatsoever. This complicates efforts to determine the capacity of foundations considerably."

Jan 1, 2005

By Fred Tarquinio, Giovanni Bonita, Lars Wagner

"A new embassy for the Peoples Republic of China is under construction in Washington, DC. The 475,000 square feet (44,125 m2) structure has five levels below ground and four above, making it the largest embassy in Washington DC. A vertical soil nail wall was used as the primary support of excavation system for the project. The soil nail wall was irregularly shaped, benched in areas, and up to 98 feet (29.9 m) in height. The soil nail and shotcrete system consisted of approximately 1,600 soil nails and 50,000 square feet (4,645 m2) of exposed shotcrete wall surface. Design and construction challenges included soft soil conditions, inside wall corners, underground utilities, seismic impacts from blasting, and logistical and political factors. Overall, wall movements were lower than expected, with maximum horizontal movement less than 0.25% of the total height of the excavation.INTRODUCTIONThe proposed Embassy of the Peoples Republic of China in Washington, DC, will consist of about 475,000 ft2 (44,125 m2) of building space and contain up to four fl oor levels above ground and fi ve levels of basement (Figure 1). When completed, the building will be the largest embassy in Washington, DC. The architect for the project, Pei Partnership Architects, along with the world-renowned architect I.M. Pei, made effi cient use of the site by inserting the building into the existing slope. Consequently, excavations reach heights up to 98 feet (29.9 m) on the southern side of the property and 42 feet (12.8 m) on the northern side.The soil nail and shotcrete system consisted of approximately 1,600 soil nails and 50,000 square feet (4,645 m2) of exposed shotcrete wall surface. The location of the building relative to the property line called for tight excavation requirements, including precise wall positions and shotcrete tolerances. Design and construction challenges included soft soil conditions, inside wall corners, arched walls, underground utilities, seismic impacts from blasting, and logistical and political factors.SITE INVESTIGATIONInformation obtained from the geotechnical investigation revealed about 10 to 20 feet (3.1 to 6.1 m) of a loose to medium dense fi ll material placed during previous site activities. The fi ll material was underlain by a silty sand and sandy silt residual soil derived from the natural weathering of the underlying bedrock. This soil sequenced naturally from a medium dense to very dense material through natural weathering of the underlying bedrock. This soil sequenced naturally from a medium dense to very dense material through natural weathering processes in the rock. The underlying bedrock was locally characterized as a gneiss. A water table elevation about 17 feet (5.2 m) above the fi nal excavation level was revealed, except in the “radius” area, where a leaking water main/hydrant generated a high local water table."

Jan 1, 2007

By Fabio Santillan, Lyndon Bedford

"This paper presents the main features of the Wolf Creek Dam Foundation Remediation Project, highlighting the innovative construction approach and stressing on how the collaboration between the contractor and the owner became a key element for the success of this project.The main rehabilitation contract, $341 M, was awarded in 2008 for the construction of a 980,000 sqft concrete barrier. Most of this 2ft-wide concrete barrier wall is being built to depths reaching 277 ft using innovative construction techniques proposed by the contractor and under quality control measures that exceed by far the industry standards.The construction of the barrier wall entails the use of nine different foundation techniques which run concurrently following very stringent requirements in terms of verticality, distance between open elements, strength, permeability and dimensions that control the installation sequence of each barrier wall element.The innovative construction approach by the contractor and the collaborative efforts by the contractor and the USACE (“US Army Corps of Engineers”) have brought this unique and very difficult project to a successful completion, setting new standards in the dam foundation industry and nine months ahead of scheduleINTRODUCTIONWolf Creek Dam is on the Cumberland River in south central Kentucky. It provides hydropower, flood control, water supply, and water quality benefits for the Cumberland River system and surrounding region. The lake is a source of recreation that has attracted more visitors (4.89 million) than Yellowstone National Park (2.87 million).The dam and its adjacent reservoir reside upon a heavily Karst bedrock foundation. In late January 2007, the USACE placed the dam under a 'high risk' for failure designation. As a temporary measure, the pool elevation was lowered to 680 ft Above Main Sea Level (“AMSL”), 80 ft below its maximum capacity, with huge impacts to the local economy while the major, and ambitious, $ 594 million remediation program to bring the dam back to its full operating condition was carried out.The main rehabilitation contract of $341 million was awarded in 2008 for the construction of a 980,000 sqft concrete cut-off barrier. Most of this 2ft-wide concrete barrier wall has been built to depths reaching 277 ft using innovative construction techniques under quality control measures that far exceed the industry standards."

Jan 1, 2015

By Emad Farouz, Francis A. Abreu

"This paper presents a case history of a successful construction-phase pile load test program that optimized the pile design in challenging ground conditions at the Great Neck Wastewater Treatment Plant in the Town of North Hempstead in Nassau County, New York. The improvements and expansion of the wastewater treatment plant included the construction of several new structures to comply with new stringent nitrogen discharge requirements and new design flow. The challenging ground conditions included up to 20-ft thick organic deposits with weight of hammer blow counts and up to 14 percent organic content and tidal ground water that was near the ground surface. The foundation design evaluated various deep foundation alternatives and selected driven closed-ended pipe piles then filled with concrete as the most suitable foundation. The selection process included considerations of cost, risk, vibrations, noise, and schedule. The contract documents utilized an innovative approach of performing an optimization load test program that was implemented during construction to optimize pile lengths and reduce potential vibration and construction schedule.This paper discusses the details of the successful load test program including static testing, dynamic testing, and the innovative contracting approach utilized to implement the construction phase load test program. It also discusses the successful development and implementation of driving criteria for production piles and construction challenges. The successful load test program resulted in savings of several hundred thousand dollars, optimized schedule, and lower environmental impacts.SITE AND PROJECT DESCRIPTIONThe Great Neck Water Pollution Control District (GNWPCD), located in the Town of North Hempstead in Nassau, New York, owns and operates a municipal wastewater treatment plant (WWTP) that discharges treated effluent through an outfall to Manhasset Bay, which is a tributary of the Long Island Sound. The site is located west of Manhasset Bay and is surrounded on three sides by local roads, and commercial, industrial, and recreational properties. The site has a gentle slope ranging from elevation +20 to +7 from west to east, respectively, based on the Nassau County Datum.To comply with new nitrogen discharge requirements and new design flows, the GNWPCD contracted CH2M HILL, Inc. and William F. Cosulich Associates as a Joint- Venture (JV) to design and provide services during construction of eight new advanced nitrogen removal facilities."

Jan 1, 2017

By Mohamed Hassan, Matthias Seip, Steffen Leppla

In the east of Frankfurt am Main, Germany, a new high-rise building is planned directly next to the river Main. The high-rise building will have a height of about 75 m and will be founded on a Combined Pile-Raft Foundation (CPRF) in the tertiary marl. The new structure will be constructed next to important, sensitive traffic infrastructure. The foundation of the new high-rise building adjoins directly existing historic quay structures, which are more than 100 years old. For analysis of the stability and the serviceability of the heavily eccentric loaded foundation of the new high-rise building and the existing structures and for the investigation of the soil-structure interaction complex three dimensional, non-linear numerical simulations have been carried out. These numerical simulations take into account all geometric and material specific boundary conditions, including the history of the construction of the whole area. The paper introduces into a very complex construction project in which the investigation of the soil-structure interaction has an important role. The three-dimensional numerical simulations are explained and the results are shown.

May 1, 2022

By Prof. Dr. -Ing. habil. Sascha Henke, Johannes Beck

The growth of Building Information Modeling (BIM) during recent years opens possibilities for integrating new digitally driven design approaches. While parametric design and algorithmic design slowly gains popularity in numerous ACE-applications, e.g. bridge design, it is rarely used by geotechnical professionals. This article presents an approach for implementation of parametric design in the BIM-based geotechnical design process. The methodology is applied to pile design and enables a real time design analysis according to DIN EN 1997-1 and EA-Pfähle 2012 considering boundary conditions such as pile position and layout, pile geometry, soil stratification and soil properties. By using intelligent attributes and scripts to control, calculate and assign them, the design analysis is directly executed in the BIM-software environment, in this case Autodesk Revit with Dynamo. This BIM integrated design approach allows multi-criteria evaluations of pile designs using aspects such as costs, environmental impact or constructability in addition to the commonly examined structural analysis criteria. As the proposed models are fully parametric, generative optimization algorithms can be applied to identify the ideal design for the entirety and each of the piles. Finally, the potential and limits of this methodology with respect to modeling, analysis, simulation and optimization are discussed.

May 1, 2022