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By M. D. Riegel, P. B. Pizzimenti, E. M. Zamiskie, Britain A. Materek

"The Skanska/Kiewit/ECCO III team (SKE) in association with HNTB was awarded the design-build contract for Phase I of the Kosciuszko Bridge Replacement Project. As lead designer for the SKE team, HNTB was responsible for the design of the Brooklyn Connector which includes construction of approximately 2000 feet of new staged earth-filled embankments utilizing prefabricated modular retaining walls (T-Walls®). The proposed embankments will be constructed adjacent to and beneath the existing Brooklyn Queens Expressway (BQE) viaduct while the existing viaduct remains in service. Critical aspects of the settlement assessment relating to the soils supporting the existing BQE will be addressed, as their behavior drives the deformation of the viaduct. Furthermore, a construction monitoring program was used to enable the designer to assess settlement predictions and allow SKE to mitigate potential impacts to the existing BQE during construction. Additionally, the methodology for installation of the embankments in a limited access area underneath an active viaduct supported on settlement sensitive shallow foundations will be presented.INTRODUCTIONSkanska-Kiewit-ECCO III Joint Venture, in association with HNTB was contracted by the New York State Department of Transportation (NYSDOT) to design and construct the Phase 1 replacement of the Kosciuszko Bridge Design-Build Project. Phase 1 of the project involves the design and construction of the new eastbound structures of Interstate 278 over Newtown Creek from Brooklyn to Queens. The project runs between Morgan Avenue in Brooklyn and the Long Island Expressway Interchange in Queens (approx. 1.1 miles) and includes the staged demolition of the existing structures."

Jan 1, 2016

By James M. Tantalla, Jr. Ellman

"Construction of the powerhouse for the Willow Island Hydroelectric Project, located at the Willow Island Lock and Dam, required a 120-ft deep temporary excavation inside the limits of a cellular cofferdam on the Ohio River side of the excavation and a soil-bentonite seepage cut-off wall on the landward side of the excavation. Stability analyses were performed for critical sections to evaluate the stability of the soil slopes and rock cuts using limit equilibrium, tension crack, and buckling analysis techniques. The stability analyses indicated adequate factors of safety through the landside embankment sections, and for the weighting berm soil slopes in front of the riverside cellular cofferdam. However, the results of deep-seated stability analyses through the rock supporting the riverside cellular cofferdam indicated marginal factors of safety for the 100-year flood condition. Consequently, the riverside portion of the excavation required enhanced stability measures, namely the installation of long, high-capacity rock anchors. Also, the dewatering system was modified to lower the site piezometric head to near the top of rock to improve the stability of the rock cuts.Thirty high-capacity rock anchors were installed on the upstream, riverside, and downstream sides of the cofferdam rock cut. The rock anchors consisted of multiple, seven-wire strands designed to provide the full-required design load at 60% of the strand capacity. Rock anchor loads varied from 1,968 to 2,074 kips. The maximum number of strands per anchor was 59. Bond lengths assumed an allowable bond stress of 100 psi based on the rock bond from pull-out tests.Project DescriptionAmerican Municipal Power, a nonprofit organization that owns and operates electric generation facilities for its member communities, has been in the process of constructing hydroelectric power plants adjacent to existing navigation locks and dams along the Ohio River. The Willow Island Hydroelectric Plant was recently completed on the West Virginia bank of the river adjacent to the US Army Corp of Engineers (USACE) Willow Island Lock and Dam. The plant is on the opposite river bank to the locks, and includes two turbine generating units with FERC rated capacity of 44MW at a 20-foot head differential. The Ruhlin Company of Sharon Center, Ohio was awarded contracts to construct both the cofferdam and the powerhouse. Construction began in mid-2011, and was completed in early 2016."

Jan 1, 2016

By Michael Moran

Typical ACIP Pile Rig [ ] Hollow Stem Auger ? Continuous flight auger ? 3 inch inside diameter pipe ? Auger diameters: 12, 14, 16, 18, 20, 22, 24, 30, and 36 inches ? Auger section lengths: 4, 5, 10, and 20 ft ? Weight ranges from about 70 lbs per ft for 12 inch to 120 lbs per ft for 24 inch and 200 lbs per ft for 36 inch

Jan 1, 2005

By Kishore Kumar B., Eswaran Prasad C R, Srini Naik B., Ramakrishna Raju N

The authors through this paper intend to introduce the non-vibro technique of ground improvement by stone column, being used for the first time in India under the Western Dedicated freight Corridor in Mumbai area. New 2x25 KV double line dedicated freight corridor tracks, capable of carrying 32.5-ton axle load are proposed to be built on this stretch. Non-Vibro Displacement Stone Columns of 900 mm diameter were installed to improve the safe bearing capacity of the soft ground to take the loading of Dedicated Freight Corridor Railway embankment. Vertical footing load tests on single and three column groups were conducted to assess the improvement in the sub-surface condition after installation of stone columns. This paper describes load tests conducted on stone columns and analysis of the obtained results. The observed load settlement behaviour of the improved ground has also been presented. Behaviour of single and group of stone columns have been compared and criteria adopted for arriving at desired factor of safety based on the settlement observed, has also been discussed.

Nov 1, 2022

By Hayel M. El-Naggar, Mohamed Sobhi, Mamdouh M. Hamza, Marawan M. Shahien

"This paper presents the results of two lateral load tests on large bored piles in soft clay deposit for a major site in northern Egypt. The tests are carried out on 0.8 m diameter piles. One of the tests is carried out on the pile where the clay starts from the ground surface. The other test is carried out on a pile after surface improvement by replacing the top 1.50 m of the clay deposit by compacted granular soil. The results of the tests show the influence of the surface replacement layer on the lateral load versus lateral displacement relationships of the loaded pile. The results of the two tests are used to calibrate a 3D Finite Element Analysis model for the pile. The model is used to investigate the influence of the thickness and lateral extent of the surface replacement layer on the behavior of laterally loaded large bored piles.INTRODUCTIONLateral loads for piles are produced by seismic events, wind, wave action, ship impact, traffic, and land slide forces. The lateral resistance of a pile is controlled by the stiffness and the strength of the material of the pile and the soil surrounding the upper portion of the pile. In most situations, the soil surrounding the upper portion of the pile is too weak to sustain the design lateral loads. Thus there is a need to increase the lateral resistance of the pile or groups of piles. Such an increase may be achieved by either increase number of piles or increase pile diameter. Alternatively, an economic way to increase the lateral resistance is to improve the soil surrounding the upper portion of the pile (Rollins and Brown, 2011; Faro et al., 2015).Ground improvement has the ability to increase the lateral resistance of the pile by increasing the passive resistance of the soil surrounding the upper portion of the pile. The ground improvement techniques have the potential for being more cost-effective and reducing construction time. In spite of this fact, such techniques are rarely implemented in practice. Further, there are relatively few tests or records available in the literature to guide engineers in evaluating the actual effectiveness of this approach. In addition, there is no standard or methodology to aid engineers in designing increase of lateral resistance with surface ground improvement. There are specific improvement methods for each soil type, whether it is loose cohesionless soil or soft cohesive soil and these methods are provided by Michell (1981), Tershai and Juran (2000), ASCE (1997), and Rollins and Brown (2011). Furthermore, there are number of case histories that add a new hole in the sight, such as the cases provided by Brown et al. (1987, 1988), Mokwa and Duncan (2001), Rollins et al. (2005), Rollins and Cole (2006), Cole and Rollins (2006), Rollins, Snyder et al. (2010) , Rollins, Gerber, and Kwon (2010), Rollins and Nasr (2010), and Gerber et al. (2010)."

Jan 1, 2016

By Michael Arnold, Jignyash Manyam, Yoav Rappaport

The USACE required construction of over 13 miles of cutoff wall at an average depth of 65 feet for the Herbert Hoover Dike (HHD). To meet project requirements, to provide quality control and make sound operational decisions, automated data capture, retention and visualization is crucial. Accurate and complete data management allows the authors to deliver critical business insights and to improve operational efficiencies. The author’s understood the necessity of capturing all their data, and efficiently processing and displaying it for multiple stake holders, for both internal and external purposes. The authors realized early in the project life cycle that data ownership and management is one of the fundamental features of the construction process. The authors developed their own software and use two in house applications; WEB-BGM online portal and, b-project which store rig production information combined with field quality control. b-project is used to create and deliver the Enterprise Database (EDB) to the USACE. Another biproduct of capturing the production data is the generation of the Geographic Information Systems (GIS) and also business analytics visual interactive display, developed through Microsoft Power BI. The paper focuses on the business process workflow and various technologies employed and lessons learned from the field operator perspective to achieve higher returns on business software operations.

Oct 1, 2022

By Nick M. Withers, Suthagarann Visvalingam, Cillian Mc Colgan

The level crossings removal project in Victoria is removing 75 level crossings across Melbourne to improve safety by separating trains from traffic, with other benefits such as reduced congestion, an upgraded road network, connected communities and support of urban regeneration. The level crossing at Station Street in Carrum forms part of the scope being delivered by the Southern Program Alliance (SPA), which is delivering level crossing removal works associated with the Frankston Train Line. At Station Street, a rail viaduct consisting of 19 spans and totalling approximately 545 m in length is under construction to remove the former level crossing. The viaduct consists of two parallel reinforced concrete Utrough girders and steel trough girders, one for each rail line. The foundations of the rail viaduct are founded on groups of Continuous Flight Auger (CFA) piles. The characterisation of geological units encountered at Carrum for the foundation design has been based on insitu testing and interpretation of test results from high strain dynamic pile testing (PDA) and Case Pile Wave Analysis Program (CAPWAP) from the Seaford Road Bridge, located approximately three kilometres South of Carrum, in similar ground conditions. By conducting pile load-deformation analyses based on pile testing significant savings were made for the client compared to the original design which was based on more traditional empirical correlations. This paper discusses the pile design methodology adopted using pile test data for this viaduct foundation. The results of this assessment are also compared to existing empirical correlations, and the limitations are discussed. The performance of the adopted pile design methodology using pile test data at Carrum rail viaduct is also discussed.

Nov 1, 2022

By Jim Slatter, Ben Collingwood

"It is well known that the adoption of an appropriate construction methodology is critical to quality outcomes for bored piles (drilled shafts). Many case studies have been published documenting quality issues that have arisen due to a range of causes involving ground conditions, ground support, drilling and cleaning techniques, groundwater, concrete properties and concreting methods, amongst other things. Despite the body of published information, pile defects remain common in practice. The authors share over 40 years’ experience in the Australian piling industry and have participated in many hundreds of projects involving bored piles in design, construction and testing roles. It is the authors’ experience that many defects are caused by conditions or practices that are known to be problematic, but that are often not recognised or addressed at the time of the works. This paper provides an overview of industry practices and key factors relevant to quality outcomes. The authors draw upon their own construction experience, published case studies and guidelines, and observations from independent pile testing activities they have been involved in across the Australian piling industry. The intent of the paper is to provide a consolidated review of typical industry practices and to highlight key areas in which construction quality can be enhanced.INTRODUCTIONThere are many published studies of cases where bored piles have been constructed and found to have concrete defects. The authors have had personal involvement in many cases where the outcomes and learnings are not publically available. The nature and cause of defects is always dependent on site and project specific factors, and therefore methodologies and materials that produce satisfactory outcomes in certain circumstances may be problematic elsewhere. The process of bored pile construction encompasses the following key areas:??excavation and ground support;??pile preparation and cleaning;??pile reinforcement and fitments.??concrete supply and mix performance;??concrete placement methodology;Each of these elements is equally important and can influence construction quality in completed piles. In the authors’ experience, it is often a combination of seemingly minor issues that leads to significant defects in piles. Conversely, attention to detail in all aspects of bored pile construction is required to produce outcomes of a consistently high standard."

Jan 1, 1900

By Joel B. Dellaria, Justin R. Lewis

"No. 9 Walton is a new high-rise condominium building located in the Gold Coast area of Chicago. The adjacent building, Walton on the Park, featured 4 levels of below grade parking and utilized a secant pile wall with integral drilled shafts to support the exterior columns. The earth retention system (ERS) for No. 9 Walton also employed a secant pile wall in combination with drilled shafts. The excavation into the soft Chicago clays varied in depth from 9.75 m to 12.5 m (32 feet to 41 feet) below grade. The temporary excavation support used internal braces from the new secant piles to the existing foundation system of Walton on the Park to provide earth retention. Engineering teams for both projects worked together to design the bracing scheme and connections to ensure that the new excavation and internal bracing would not overstress any elements of the existing structure. Further complicating the project, immediately to the west of the project was a historic church founded on shallow spread footings which required underpinning to minimize movements.The project involved three different building owners, small values for acceptable wall movement, an extensive monitoring program and the challenges of merging two earth retention systems. The subsurface conditions at the site, the adjacent structures, the excavation, and the performance are described. A summary of the design methods and the expected movements of the ERS are discussed, and the performance monitoring system is described. Overall, the ERS performed better than expected with less than 1 inch of measured lateral wall movement during and after the excavation was completed. Measured performance of the ERS is compared to the predicted performance and to the performance requirements for the project.INTRODUCTIONNo. 9 Walton is a new high-rise condominium building in Chicago located in the Gold Coast. The building has 3 levels of below grade parking and 36 levels of living space above grade. Developers originally slated the project to be Phase 2 of the Walton on the Park development built in the mid 2000’s, using portions of the existing foundation system for development of the new structure. However, the housing market crash in 2007 prompted cancellation of Phase 2 of the Walton on the Park development. The property sat undeveloped until 2015 when design and construction for No. 9 Walton began under a new development and design team. The project team completed foundation excavation and below grade structures in 2016 with the first units of the building turned over to new homeowners in 2017.The structural design for No. 9 Walton consisted of reinforced concrete columns and slabs, supported laterally by a heavily reinforced concrete central core. Drilled shafts to rock supported the interior columns and core with the exterior columns and foundations integrally included in the earth retention system. The structure had a below-grade footprint of approximately 1,490 m2 (16,000 ft2). The general excavation extended 9.75 m to 12.5 m (32 feet to 41 feet) below street level with the deepest portions at the central building core mat foundation."

Jan 1, 2017

By Kyle R. Lackner, Jared P. Williams

"The Sutter Butte Flood Control Agency initiated the Feather River West Levee (FRWL) Program in 2010 to bring 35 miles of levee along the Feather River into compliance with applicable Federal and State standards for levees protecting urban areas. A combination of soil-bentonite cutoff walls, soil-cement-bentonite cutoff walls, and seepage berms will reduce flood risk by correcting under and through seepage deficiencies and remove more than 34,000 properties from the FEMA Special Flood Hazard Areas. The FRWL program includes a combined total of 7,744,803 square feet (SF) of cutoff wall planned to be constructed between 2013 and 2015. Cutoff wall construction methods to meet the design depths included conventional excavation to a depth of 85 feet and deep soil mixing for depths up to 120 feet. A key component of the FRWL program was the development of site specific mix designs using the design boring logs to evaluate the expected backfill gradation and permeability results. Issues that required a partnership between Contractors, Owner and Engineers included substantial Archaeological and Cultural Resource delays, significant depth changes due to a change in competent key, right of way acquisitions for abutting land, and the magnitude of the project in a resource limited industry.IntroductionThe Feather River watershed basin is located 50 miles north of Sacramento, CA and incorporates the agriculture producing communities of Yuba City, Live Oak, Gridley and Biggs. These communities are protected from flooding by levees that contain under-seepage and through-seepage deficiencies and were the cause of major failures in 1955, 1986 and 1997. The Feather River West Levee (FRWL) program was initiated by the Sutter Butte Flood Control Agency (SBFCA) in 2010. The long term objective of SBFCA is to correct the levee deficiencies and provide 200 year flood protection to more than 34,000 at risk properties located within the FEMA Special Flood Hazard Areas.Although FRWL contained a variety of construction components such as earthwork and pipe replacement, the slurry cutoff wall is the primary construction element for addressing under and through seepage deficiencies. From 2013 to 2015 approximately 6,649,210 SF of cutoff wall were installed using conventional excavation and deep soil mixing (DSM) techniques leaving 1,095,593 SF to be completed in 2016. The work was designed, solicited and constructed under two separate contracts, titled Project Area C and Project Area B&D. A summary of the contracts and cutoff wall quantities is presented in Table 1."

Jan 1, 2016

By Alexander Ciccone, John H. Gill

Jet grouting is a highly versatile ground modification technique that can offer significant commercial and technical advantages over traditional concrete pit underpinning applications. Despite these advantages, jet grouting remains an underutilized technique in the construction industry due to its perceived complexity, cost, and risk. When performed thoughtfully, underpinning by jet grouting offers significant safety and schedule advantages over traditional underpinning approaches. The New England construction market has seen a recent acceptance in the use of jet grout underpinning on congested project sites across a variety of subsurface conditions. The reduction of the cement batch plant footprint due to equipment advances has allowed the use of this technique in urban sites where its use would be previously infeasible. Furthermore, jet grout underpinning has been utilized for support of historic and sensitive structures with generally lower tolerance to settlement than is typically feasible with conventional pit underpinning. Robust, real-time geotechnical instrumentation monitoring systems have helped reduce the uncertainty and further expand the feasibility of jet grout underpinning applications. When properly designed and constructed by qualified and experienced jet grouting contractors, the flexibility of soilcrete for design and construction may be utilized to overcome the many inherent challenges which complicate underpinning and earth retention systems. INTRODUCTION The construction of buildings and infrastructure in our increasingly dense urban spaces often requires excavations below the elevation of existing structures immediately adjacent to the proposed work. Where a proposed excavation system encroaches into an existing structure’s zone of influence, additional measures, such as the construction of an underpinning or excavation support system, are required to safely excavate and minimize the impacts on the adjacent structures. Jet grouting is one method of underpinning that offers significant commercial and technical advantages over many other techniques. Though it was first used to the United States in the 1980s and has grown in popularity elsewhere, jet grout underpinning remains underutilized domestically due to its perceived cost and risk premium. Jet grouting has significant technical advantages over other underpinning methods due to its applicability in a wide range of soil types and its flexibility of design and installation. The jet grouting process is capable of limiting the movement of foundations during construction and excavation to lower thresholds than most traditional underpinning methods (Droof, Furth, & Scarborough, 1995). Its use for underpinning historic and sensitive structures with lower settlement criteria provides additional evidence to its technical utility. Through thoughtful design, adequate planning, and experienced installation, jet grouting can be an appropriate underpinning solution that can provide significant cost and schedule savings.

Jan 1, 2019

By Eleonora Di Mario, Colin B. Turnbull, Matthew G. Mills, Chengbin Miao, Wilhelm S. Degen

"In the past decade, the ‘zero-dredge’ philosophy has become the preferred option for the formation of marine seawalls and reclamations, compared to the partially or fully dredged options, as this solution presents several environmental advantages. Recent relevant project experience is presented herein in order to highlight key design principles and construction issues central to the successful construction and performance of a sloping rubble seawall founded on soft soil improved by stone columns. If designed and installed with proper quality control, correct treatment intensity and sensible construction staging, stone columns are a safe and cost effective method for seawall foundations. This paper provides guidelines with regards to the design, construction and quality control for the correct implementation of stone columns as a foundation element for sloping rubble marine seawalls.INTRODUCTIONBenefits of sloping marine seawalls founded on stone columnsTo suit the current environmental requirements in Hong Kong, recent projects are tending to favour zero-dredge solutions, such as the Hong Kong Boundary Crossing Facility and the forthcoming Three-Runway System. The installation of stone columns allows the underlying deposits, generally consisting of very soft to soft clay and silt (soft soil), to improve in strength to the extent that the seawall can be directly placed on the seabed. This negates the need to dredge the soft soil and, therefore, this ground improvement technique represents an ideal solution for zero-dredge projects.Stone columns can also provide several other beneficial effects, including: accelerated drainage, reduced settlement, increased slope stability and soil reinforcement in the event of an earthquake. Stone columns, in contrast to competing cementitious methods, are a very ductile foundation method. This ductile behaviour is part of the design concept of stone columns in soft soil. Past projects located in Hong Kong and elsewhere, with an improved soft soil layer thickness of over 15m, have shown that stone columns can remain fully functional in terms of both drainage and horizontal reinforcement, even after settlements of over 3m and lateral displacements of up to 1m have occurred."

Jan 1, 2017

By John P. Turner, Mark Jen, Bobby Daita

"The Port Authority of New York and New Jersey is replacing the existing Goethals Bridge built in 1928 which is deemed to be functionally obsolete. The replacement bridge will consist of a dual cable-stayed Main Bridge crossing the Arthur Kill with elevated approach spans connecting Elizabeth, New Jersey and Staten Island, New York. The main bridge towers are supported on a group of six nine-foot diameter drilled shafts that transition into a pier cap. The anchor and approach piers are supported on two column bents with each column supported on a single drilled shaft. The 4.5 to 10 feet diameter drilled shaft foundations have permanent steel casing to rock and socketed into bedrock. Subsurface conditions consist of Passaic Formation bedrock overlain by varying thicknesses of overburden soils. The foundation design assumes permanent casing extending a minimum 2 feet into the weathered bedrock. Rock socket lengths below the permanent casing vary between one to two shaft diameters based on the quality of the bedrock. The reinforcing design was based on AASHTO LRFD minimum requirements, force demands, seismic detailing requirements and also considering the continuity between the shaft and socket.The bridge is currently under construction with approximately 70 percent of the foundations installed. Several field conditions encountered at various stages of shaft construction between casing advancement and concreting required design and construction modifications. Based on the driving method and the quality of the bedrock, the tip of the permanent casing hit refusal either above or below the design elevation, requiring modifications to the drilled shaft design and its reinforcement. This paper provides an overview of the general subsurface conditions at the site and its impact on foundation design and discusses the detailing worked into the design to accommodate tip elevation variations, as well as various foundation design modifications in response to actual conditions encountered during construction."

Jan 1, 2016

By Melinda J. Hummel, Zachary T. Smith, Nathaniel Witter, Nina F. Carney

The revitalization of Pittsburgh’s historic Strip District has led to the redevelopment of existing properties and the development of new properties. At one time, the Strip was home to wholesale market products. Now, the historical warehouse buildings are being converted to multi-use residential and commercial properties. One such property, 1600 Smallman Street, consisted of 1 to 6-story connected buildings that housed night clubs, retail shops, and office space. The lower story portion of the building, on the southwest side of the property, was torn down to make room for a new 5-story- parking garage with street level retail space. The remaining 6-story-building, on the northeast, was gutted to be renovated into high-end condominiums, keeping the exterior historical building facade.

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 Raffaella Granata, Daniele Vanni

"This paper presents the drilling and grouting program performed at two abandoned landfills located into former calcarenite rock quarries in Manfredonia, Italy. Tests performed after the abandonment of the landfills detected leachate infiltration into the groundwater, which required the implementation of a remedial program. In order to seal the rock fissures and create an impervious basin at the base of the two landfills, sub-horizontal boreholes were drilled and grouted into the rock under the waste deposits. At the same time, sub-vertical boreholes were drilled and grouted along the perimeter, to laterally confine the landfills. Finally, the landfills were properly capped with an HDPE membrane, geogrid, geotextile and topsoil. The methodology implemented to create a watertight barrier under the two landfills was innovative and cost-effective. Moreover, the drilling and grouting minimized the environmental impact of the remedial work, since the waste remained in their original location and were not affected by the remedial process.IntroductionThe two landfills, “Pariti-1 RSU” and “Conte di Troia”, are located approximately 6 km (4 miles) southwest of Manfredonia, a small town close to Foggia, Italy (Fig. 1). These landfills are located into two rock quarries, formerly used for the extraction of calcarenite (i.e., a weak calcareous sandstone, in tuff facies), and were abandoned in the early 90s. The two landfills cover a total area of about 45,000 m2 (11.2 acres), and mainly include urban solid waste with a depth of up to 25 m (82 ft). The main characteristics of the two waste landfills are listed in Table 1."

Jan 1, 2016

By Brandon T. Buschmeier, Sonia S. Swift, Michael P. Walker, Frederic Masse

"Ground improvement has undoubtedly become a cost-efficient and effective solution to support the development of poor soil sites. Ground improvement elements, such as Controlled Modulus Columns (CMCs), replace piles by improving the subsurface soils and reducing settlement. As ground improvement becomes more popular, the applications become more creative and ground improvement is being used to control settlements under large structures with tight settlement tolerances.In this paper, we will discuss the use of CMCs to support two (2) large industrial warehouses where soil conditions would normally lead to the use of deep foundations and a structural slab, grade beams, and hung utilities to prevent excess settlement. Each of the sites we will discuss had poor soil conditions in the form of very soft or compressible soil, heterogeneous fill of varying thickness, and environmental contamination. At each site, we developed a design that would allow for the use of Controlled Modulus Columns (CMCs) with a Load Transfer Platform (LTP) in place of the previously-proposed deep foundations. The use of the CMCs also allowed for the use of spread footings and slab on grade construction. The benefits of this value-engineering approach include economy in the foundation system, risk mitigation by not disturbing contaminated soils requiring expensive removal, and ease of access for future sub-slab upgrades with new tenants. Additionally, the use of recycled concrete aggregate as an LTP is more environmentally friendly than placing structural slabs with heavy steel reinforcement.Designing for the settlement of large warehouses is challenging because it requires changing how we typically perform our designs. For most structures, the slab loads are relatively light when compared to the footing loads, whereas for warehouses, the slab is heavily loaded compared to the relatively light footing loads. Thus, it becomes essential to perform three-dimensional analyses to confirm that the proposed CMC layout will provide uniform support of the slab and footing across a variety of loading scenarios (loaded bays vs unloaded or travel bays). The complexity of the designs for these warehouses generated interest in conducting large area load tests over a grid of multiple columns. The performance of the area load tests provided invaluable information on the effectiveness of the LTP and CMC spacing. In this paper, we present a general description of CMC ground improvement, the differences between ground improvement and traditional pile foundations, our typical design methodology for CMC design, and the modifications to that methodology for warehouses."

Jan 1, 2017

By Shoichi Tsukuni, Akihiko Uchida, Kazuo Konishi

"In order to investigate the effect of grid-form deep mixing walls as a countermeasure for liquefaction damage to roads and private houses in Urayasu, Japan, three dynamic centrifuge model tests were conducted. Urayasu is located in the Tokyo Bay area, and private houses in the city incurred severe damage due to liquefaction during the 2011 Tohoku earthquake. In grid-form deep mixing walls design, the distance between grid-form walls is critical to prevent liquefaction. This study clarifies the relationship between the settlement of private houses and the distance between grid-form walls under the conditions that exist in Urayasu.INTRODUCTIONMany private houses in Urayasu, Japan suffered severe damages due to liquefaction during the 2011 Tohoku earthquake (Photograph 1). Fig. 1 shows the location of Urayasu and the maximum acceleration of the observed seismic waves in the Tokyo Bay area. At Urayasu, the duration of the seismic waves (hereafter called the Urayasu Wave) was about 2 min. The maximum acceleration was 1.57 m/s2 (Fig. 2), which is relatively small. The damages occurred in the land reclamation areas that consist of loose sand with an SPT-N value less than 10.To prevent liquefaction in future, it is necessary to adopt suitable countermeasures in the areas where many private houses suffered severe damages. Grid-form deep mixing walls are one such countermeasure. Fig. 3 and Photograph 2 show grid-form deep mixing walls. Walls are constructed using the deep cement mixing method. Fig. 4 shows a plane view of planned grid-form deep mixing walls for roads and existing private houses in Urayasu."

Jan 1, 2015

By Kirk Ellison, Eric S. Lindquist, Peter Faust, Stephen M. McLandrich

"The 181 Fremont Tower will be an 800-foot high-rise with a 60-foot deep basement located in a dense urban part of downtown San Francisco. The design and construction methods of the subsurface elements navigated a variety of site constraints such as loose fill and soft estuarine soils, shallow groundwater, contaminants, historic obstructions, small work area, proximity of adjacent buildings, and the on-going excavation and build-out of the adjacent Transbay Transit Center (TTC) train box. Design of the approximately 260-foot-deep drilled shafts (some of the deepest foundations ever constructed in San Francisco) was proven by a full-scale load test that provided unique data on the frictional capacity of the deep soil and Franciscan Complex bedrock in the region. Design and construction of the shoring system for the 5-story basement excavation was exceptionally challenging because of the on-going construction for the TTC. To allow for flexibility during construction, hydraulic rams were placed in a transfer waler along the shared TTC shoring wall that could adjust the forces transferred through to the TTC excavation if required. Open and steady communication between the shoring engineer, the geotechnical engineer, and the shoring/foundation contractor was crucial in order to satisfy the complex constraints of this site.INTRODUCTIONThe 181 Fremont Tower is a new build mixed-use tower, currently under construction in the dense urban core of the South of Market District of San Francisco, California. This high-rise will consist of 54 above ground floors with the roof level 700 feet high. Atop the roof will be some architectural features including a spire that will top out at just over 800 feet, which will make it the second tallest building in San Francisco upon completion.The tower is being developed by Jay Paul Company and the architectural design is by Heller Manus. The structural engineer and geotechnical engineer for the project is Arup North America Ltd (Arup). The shoring designer is Brierley Associates (Brierley). The general contractor is Level 10 Construction (Level 10) and the specialty foundation contractor and excavation contractor is Malcolm Drilling Co., Inc (Malcolm)."

Jan 1, 2017

By Shreya Vivek Hokam, Dr. A. I. Dhatrak, S. W. Thakare, Dr. Vivek S. Hokam

Construction in congested urban areas has necessitated tall and massive structures. In urban areas, it is common to construct underground structure nearby existing buildings. Selection of an appropriate support structure system to be implemented in the excavation in an urban area is heavily dependent upon the geotechnical conditions and safety of the surroundings and neighbouring structures. Urban Rail, popularly referred to as Metro Rail, has seen substantial growth in India in the recent years. More cities are experiencing the need for metro rail to meet their day-today mobility requirements. The metro structures involved deep excavation for foundations which induces the stresses and thereby alters the existing equilibrium and thus may affect stability of neighbouring structures considering safety point of view. Hence, design and execution of deep excavations become one of the important challenging tasks of any geotechnical engineer in the modern era. Further, it is important to control the ground movement in order to prevent the failure of excavations. This involves specialized foundation technologies, usage of sophisticated equipment and new methods in underground construction, safety and monitoring systems. In this paper the methodology used for protecting adjoining structures due to deep excavation for Nagpur Metro station is studied.

Sep 1, 2022