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By Davide Grassi, Joel Joaquin Cortez, Giovanni Spagnoli, Nick Chittenden

Grouting is a technique used to improve the engineering properties of soils and rocks. Grouting techniques are classified under different criteria: injection method used, type of grout material injected, typical application, and the sequence of construction. The best-known criterion is the mode of entrance or admission of grout into the soil or rock. It is possible to identify therefore several grouting techniques: compaction, fracture, jet/mixing and permeation. The function of penetration grouting is to reduce the permeability of the soil or rock and/or increase the strength and density. In order to avoid displacement, permeation grouting shall be carried out at carefully controlled pressures and flow rates, using appropriate grouts. Colloidal silica is an innovative binder which has low viscosity (about 5 m·Pas), it is not toxic (pH lower than 9) and it is workable between +5°C and +45°C. This paper presents several case histories: a consolidation job related to the installation of a new sewer in North Italy in cohesionless soils, water stopping injection in a weathered granitic bedrock in California, permeation works in the US in sandy soils to improve excavation and the installation of sheet piles in the UAE. Results show that the colloidal silica an innovative and robust technology to perform grouting in very fine soils where conventional binders or micro-fine cements cannot penetrate.

May 1, 2022

By Peter Faust, Peter Hubbard, Kenichi Soga

The European Federation of Foundation Contractors (EFFC) and The Deep Foundations Institute (DFI) have set up a task group to compile a Guide for Working Platforms. The first edition of this Guide has been published in January 2020. The aim of the Guide is to provide reliable methods for design, testing and verification of working platforms for construction equipment, especially in the deep foundation industry where track loads can be excessive due to the nature of its operations. The Guide has identified areas where knowledge is limited. Actual track pressure and its distribution along the length of the tracks is still not well researched. Current recommendation provided in EN 16228-1 are believed to be overly simplified and may lead to conservative requirements for working platform thickness. This paper presents results of a series of field tests where the actual track pressure of a large drilling rig during operation was measured in real time together with the deformation of the working platform. Embedded, distributed fiber optic sensing (DFOS) at different depths throughout the platform allowed for a three-dimensional evaluation of the platform deformation throughout the entire operation. Results will help to develop more reliable recommendations for future safety requirements of working platforms for deep foundation equipment.

May 1, 2022

By Xavier Pita, Alexandre Pinto, António Cristovão, Rui Tomásio

"The cutter soil mixing technology was been applied in Portugal since the last seven years. The aim of this paper is to present the main design and execution criteria, related with both the cofferdam and foundations solutions, using soil-cement panels, reinforced with steel profiles, at the new Leixões Cruise Terminal, located at the Leixões Port, in Portugal. The Terminal building was built with one basement on a marine environment, over very difficult geological and geotechnical conditions, which demanded the use of some unusual and integrated geotechnical solutions. It is also pointed out the importance of the QC/QA, as well as the technical, economic and environmental advantages of the cutter soil mixing technique, comparing with same more conventional solutions.1 INTRODUCTIONThe construction of the new Cruise Terminal at Leixões, main gate of the Atlantic Ocean to the North of Portugal and Spain, as a consequence to the constant increase of the cruise traffic, was a challenge from both the geotechnical and structural point of views, mainly due to very difficult and unusual conditions, ranging from the geological and geotechnical scenario to the existent and under operation Leixões Port infrastructures, mainly the South break water, as well as the existent cruising boarding deck (Figure 1).According to the Terminal Project it was necessary to build one basement below the water table level, including several earth retaining structures in order to allow the excavation works on dry conditions leading to a global cofferdam effect. For this purpose soil - cement panels, using CSM technology, reinforced with steel profiles, micropiles (both for foundation and cut off effect) and the existent sheet piles were used. Also pointed out are the adopted special foundations of a very complex structure, including bored piles and micropiles (Figure 1)."

Jan 1, 2015

By Gustav Jahner, Michael Baltrusch, Norbert Hoffmann

Near the port city of Whitby in the north-east of England, Anglo American (AA) is setting up the deepest mine in the UK, which will have a depth of 1,500m. The purpose of the project is to extract and transport polyhalite, both underground, and to market it globally. As part of the construction works, BAUER Technologies Ltd, the UK subsidiary of BAUER Spezialtiefbau GmbH, constructed three different shafts using the diaphragm wall technique, with depths of up to 120m. In order to ensure the specified vertical tolerance of maximum 200mm, several measurement methods were applied, and the results were documented in a 3D model. Complex de-sanding plant technology and specially developed polymer products were adopted to regenerate the trench supporting bentonite-slurry.

Sep 1, 2022

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

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

Jan 1, 2017

By P. J. Nicholson

The methods of reinforcement to be discussed in this paper are all insitu methods, ones that can be used on the soil structure as it exists in the ground, and do not rely on excavation and replacement of the soil. Current practice in the United States, as well as new ideas and methods, will be discussed as they relate to slope stability, retaining walls, and to other uses such as control of mine or cavity related subsidence and to liquefaction control under existing structures. The method is based on the concept of "nailing" or reinforcing the soil in place, and thereby causing a mass of soil to act as a coherent unit. When performed properly, a true gravity structure can be constructed, one that will remain intact under both horizontal and vertical loadings and that will also resist vibrational and seismic loadings.

Jan 1, 2010

By Patrick J. Hannigan, Seth Robertson, Frank Rausche, Rozbeh B. Moghaddam

The Top-Loaded Bi-Directional Test (“TLBT”) and the conventional Bi-Directional Load Test (“BDLT”) are full-scale load tests where loads are applied bi-directionally to the foundation element. The BDLT uses an embedded loading source consisting of a jack assembly with one or multiple hydraulic jacks located between two steel bearing plates. As the jack(s) within the jack assembly is/are pressurized, the plates receive the load from the jack(s) and transfer these loads to the foundation element. In the case of the TLBT, the loads are also applied bi-directionally to the foundation element. However, in the TLBT case, the loading source is located above the foundation head. With the TLBT’s non-embedded and reusable load assembly, the loads are applied to the foundation using the steel shaft bearing and base bearing plates cast within the foundation. These plates are connected to the load assembly at the foundation head via Grade 75 or Grade 150, threaded, steel bars. This paper presents comparison results from a full-scale load test performed by both bi-directional load testing methods on adjacent test shafts. Details regarding subsurface conditions as well as test shaft construction and installation are included for the comparison tests. Test results and corresponding analyses are presented and discussed in detail.

Sep 8, 2021

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 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 Venugopal B, M Kumaran, Thomas John, Vetriselvan A

The initial pile load tests are conducted to ensure the geotechnical capacity of the pile in a particular site condition. Normally kentledge method is adopted for the compression pile load tests. In this method the entire kentledge load is loaded above secondary beams which are supported by concrete blocks above the Natural Ground Level. So, it is important to ensure the SBC (for shear and settlement) of the natural ground. In one of our projects initially it was decided to go with kentledge system for initial compression load test on 56m long 1200mm diameter BCIS pile. The test load and total kentledge load were 2160t and 2700t, respectively. The soil strata mainly consisted of clay with low SPT N value and water table almost at ground level. It was suggested to replace top soil using Granular Sub-base (GSB) with good compaction in order to avoid excessive settlement of concrete blocks placed to support the kentledge weight. When the kentledge loading started, even before reaching 10% of total kentledge load, excessive settlement on the GSB layer was observed. This paper describes the problems faced during normal kentledge method and how it was overcome using the liner pile system for initial compression load tests in this particular site condition for higher test load.

Nov 1, 2022

By Kalyani Devabhaktuni, Mike Minton, Mark T. Howe, Yan Zhang

During the procurement phase of a Design-Build (DB) project, design-build contractors must often commit to a fixed price based on limited or incomplete geotechnical information. This lack of information can result in an inaccurate assessment and allocation of project risk to either the contracting authority or the DB contractor. This paper presents a case study of an elevated water tank supported by mixed ground improvement techniques, including Vibro-Compaction (VC), Aggregate Piers (AP) and Compaction Grouting (CG) in East St. Louis, Illinois. An adaptive design and contracting approach provided the best value solution for a complicated set of geotechnical problems, including static bearing capacity and settlement concerns as well as liquefaction induced settlement. Close cooperation between the owner, the tank contractor, the geotechnical engineer and the ground improvement contractor was essential to produce an effective solution. Ground Improvement techniques resolved the geotechnical challenges at the site through adaptive design methods, utilizing progressive rounds of verification and real time data acquisition to achieve performance objectives. This paper details the evaluation of geotechnical criteria, the selection of ground improvement techniques, the adaptive design and implementation of ground improvements, as well as contracting methodologies used to ensure that the best value was provided. PROJECT INFORMATION In November, 2016, CB&I Storage Tank Solutions (McDermott) submitted a design/build proposal for an elevated water tank for Illinois American Water Company (IAW) in East St. Louis, Illinois. The purpose of this tank was to have backup water capacity for power generation. In the RFP, IAW requested two alternate styles of tank: Option 1, a 1250 Million Gallon (MG) Composite Elevated Tank or Option 2, a 1250 MG Waterspheroid tank. Option 1 consisted of a steel tank supported on a concrete tower. Option 2 consisted of a steel tank supported on a steel shaft. The height (determined by IAW) was 140 feet to the top capacity line measured from top of floor slab.

Jan 1, 2019

By Clarissa Aguiar, Seok hyeon Chai, Thamer Yacoub, Sina Javankhoshdel

Sheet piles are used as an excavation support for soil retention. They are interlocked systems to form a wall for earth support along with anchors to provide an extra lateral support in excavations. The earth pressure against a sheet pile structure is not unique for each soil, but rather a function of soil-structure system. Movements of the structure with respect to the soil are primary factor in developing the pressure and thus the problem becomes indeterminate. In order to model a sheet pile wall for the analysis, structural element/interface can be used for the sheet pile. However, the use of the structural element with soil model alone is insufficient to simulate this soil-structure system as it fails to capture the slip condition between the sheet pile and the retained soil. In order to capture this slip condition, an interactive element can be used between sheet pile and soil to allow slip to occur. There have been many case studies where this method was used to analyze the response of the retained soil. Numerical studies have shown a good agreement with experimental results, but this stiffness is often not a well-known parameter, due to its complexity in nature of interactive behavior between soil and sheet pile walls. Also, many case studies are carried out with twodimensional analysis of the foundation, where three-dimensional analysis may be more suitable in some practical applications. In this paper, the interactive behavior of the element between sheet pile and soil is investigated with case studies for staged excavation using sheet piles and anchors. Then, investigation of a three-dimensional model is carried out by comparing with two-dimensional analysis.

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 Harry Schnabel, Mitchell L. Fong, Douglas R. Jenevein, Thomas S. Lee

"The Warm Springs Extension (WSX) is one of a series of projects that will eventually extend the Bay Area Rapid Transit System (BART) from Fremont to San Jose, California. A cut and cover tunnel was used for a portion of the extension that runs through Fremont Central Park to minimize the impacts that an at-grade railway would have on the Park. A cement deep soil mix (CDSM) wall was selected by the engineer as the preferred method of providing structural support and groundwater cut-off for a portion of the tunnel where it passes through an important aquifer and near Lake Elizabeth. In addition to the CDSM wall, a jet grout plug was constructed at the base of the tunnel to provide a complete groundwater cut-off.This paper will discuss the unique quality assurance and quality control measures taken for the soil mix wall and jet grout plug as well as the methods used to repair leaks and mitigate water seepage through the exposed wall and grout plug.PROJECT DESCRIPTIONThe Bay Area Rapid Transit (BART) Warm Springs Extension (WSX) project is located south of the existing Fremont BART station extending 8.9-km (5.4 miles) to Warm Springs District in Fremont, California. The WSX project has been divided into two contracts with different delivery methods. In order to minimize impacts to Fremont Central Park, a subway was selected at this portion of the alignment under a conventional design/bid/build contract.The Fremont Central Park Subway (FCPS) which begins on the south side of Walnut Ave and ends just north of Paseo Padre Parkway and is about 2.3-km (1.4 miles) long. Fig. 1 shows the entire WSX and the FCPS project. The FCPS contract consists of a cut-and-cover subway box, subway transition structures, ventilation structures and a section of which transverses Lake Elizabeth (a man-made lake). The geologic conditions consist of fill (sand, silt, clay and construction debris), Young Alluvium (clay and silt), Basin Deposits (clay, silt, and sand), and Older Alluvium (sand and gravel) as shown in Fig. 2.HYDROGEOLOGY OF THE PROJECT SITEThe FCPS is dominated by two geologic features - the Hayward Fault and the Above Hayward Fault (AHF) aquifer. The AHF aquifer provides a significant source and storage of water for the local water district. The underground subway will penetrate this aquifer and is up to 11m (36 ft) below the groundwater table. No groundwater was allowed to be pumped during construction of the subway box by Alameda County Water District (ACWD). To facilitate excavation for the subway box, temporary cut-off walls and a grout plug were designed to retain and resist high differential hydraulic pressure. The following section describes the selection of a deep soil mixing method for water cutoff. Design of the grout plug has been described in Lee, et al., 2011 and Fong and Lee, 2009, and is not the focus of this paper."

Jan 1, 2015

By Darren S. Diehm

"Construction for the restoration and expansion of 102-year-old Wrigley Field in Chicago, Illinois began at the conclusion of the 2014 baseball season. This six year project involves structural upgrades to the Stadium, improvements to the facade, infrastructure, restrooms, concourses, suites, press box, and bullpens, as well as the addition of restaurants, patio areas, batting tunnels, video boards, an adjacent Office-retail Tower and a new Hotel. The Bleachers were demolished and replaced, and a new underground Clubhouse was constructed for the Chicago Cubs beneath a new open-air Plaza. The 1060 Project is privately funded, projected at $750 million (US). The work will be completed in phases during consecutive off-seasons, each with a maximum 23-week duration extending through the Chicago winter. Ownership mandated that on-going construction cause no disruption to the Major League Baseball season, have no impact on hosting concerts and other special events, and it should not adversely affect seating capacity, or diminish the fan experience.The 1060 ProjectAfter purchasing the Chicago Cubs baseball team in 2009 from the Tribune Company, the Ricketts family began planning the renovation and improvement of Wrigley Field and its near neighborhood surroundings in Chicago, Illinois. What came to be known as the 1060 Project was officially announced at the annual Cubs Convention in 2013. Construction began on the $750M privately funded project in October 2014 at the conclusion of the Major League Baseball season. In their vision, the Ricketts committed the 1060 Project to three primary goals. First and foremost as a MLB franchise, the work should provide a meaningful contribution toward winning the World Series and ending the championship drought which stretched to the last win in 1908. Second, the project should be focused on preserving and improving Wrigley Field. Finally, the project should be committed to outcomes that enable the team to be a good neighbor and provide economic and social benefit to the local community.Constructed as Weeghman Park in 1914 for an estimated total cost of $250,000, the stadium provided seating for 18,000 fans and a home for the Chi-Feds and Whales of the National Federal League. The Chicago Cubs were enticed to move from the West Side Grounds in 1915. In the next 100 years, the Wrigley Field would be sliced apart and expanded, double its seating capacity with the addition of double deck grandstands, be enclosed by bleachers (and an ivy covered wall), and, in 1988, experience its first nighttime baseball game with the addition of lighting.The 1060 Project has a total budget of $750M, with an expected construction value of $350M. It is projected to add over 2,100 jobs to the economy and be completed before the 2020 baseball season. The work will be completed in phases during consecutive off-seasons, each with a maximum 23-week duration extending through the Chicago winter. Ownership mandated that on-going construction cause no disruption to the Major League Baseball season, have no impact on hosting concerts and other special events, and it should not adversely affect seating capacity, or diminish the fan experience."

Jan 1, 1900

By Paul M. Schuman, Alessandro Bertero, Giuliana A. Zelada, Sharon G. Cranston

Many jet grouted columns were recently installed to create a jet grout-treated soil foundation for an earthen embankment used in a large shoreline stabilization project in the Mystic River in Charlestown, MA. A physical test program was used to determine whether the jet grouting parameters the Contractor selected would meet the design requirements given the local soil variability, including soft river sediments and organic soils. The presence of hydrocarbons encountered in the marine sediments during the test program caused concern that the design strength could not be achieved. The published literature discusses the environmental aspects of jet grouting with hydrocarbons. The literature did not include many studies of the effect on jet grout-treated soil strength for the types and concentration of hydrocarbons encountered on this project. The grout mix, air pressure, and number of passes of jet grouting were varied in a second field test program to determine jet grouting parameters needed to achieve the design strength of columns with hydrocarbons. A geo-probe study was performed to identify the type and concentration of hydrocarbons on the site. With few exceptions, the quality control core samples from the production columns met the design requirements with many strength values far exceeding the design strength. This paper presents the data, and reviews the lessons learned. PROJECT BACKGROUND The Charlestown Bus Garage, located in Cambridge, Massachusetts, is a Massachusetts Bay Transportation Authority (MBTA) bus maintenance facility located on the Mystic River. The site was home to a coal gasification facility before it was developed by the MBTA as a bus garage in 1978. A deadman-anchored steel sheet pile bulkhead wall installed along the Mystic river on the east side of the site supports the site grade at about El. 11 ft (NAVD 1988) (Figure 1).

Jan 1, 2019

By Eric P. Bregman, Justin Zarrella, Ryan M. Coulson, Connor Johnson

Within a prominent Boston, MA suburb are a pair of historic stone and mortar structures built in the late 1800’s. Both the Main House and Carriage House have been maintained and occupied throughout their rich history, but renovations were needed to address structural concerns and building code compliance issues. The focus of this paper is to detail an innovative underpinning design that addressed ongoing settlement issues at the Carriage House. GZA GeoEnvironmental, Inc. (GZA) partnered with Phoenix Foundation Company, Inc. (Phoenix) to design foundation wall support systems for Consigli Construction Company (Consigli) that would effectively underpin the historic field stone foundations. Originally, conventional concrete pit underpinning and jet grouting were contemplated as methods for support. However, due to the age and condition of the existing foundations, worker safety concerns, and the risk of additional structural damage, GZA/Phoenix elected to pursue a less traditional approach. The alternate design consisted of micropiles used for combined temporary and permanent foundation support. The load transfer system included steel headers with needle beams cored through the field stone foundation walls and reinforced concrete grade beams/pile caps. To validate design performance and ensure worker safety, GZA installed a fully automated survey monitoring system to record lateral and vertical building deformations. This included real-time email alert notifications to inform the Project Team of any threshold exceedances. From the start of micropile drilling through full load transfer to the temporary support and permanent foundation systems, the underpinning performed as designed resulting in less than 3/16-inch of vertical and horizontal deformations observed. This magnitude of movement is less than half of what is generally accepted deformation tolerances for masonry structures and considered exceptional performance. The focus of this paper is to provide additional details on the unique design, sequencing, installation, and performance of the underpinning systems.

Sep 8, 2021

By Louay Owaidat, Daniel Jabbour, Allan Frappier, Jose Gomez, Mark Stanley, Tino Maestas

The U.S. Army Corps of Engineers (USACE) is implementing a levee strengthening program along the Sacramento River East Levee (SREL) designed to correct 11 miles of deficient levees as identified by recent hydraulic and geotechnical investigations. The first project, the subject of this paper, completed in 2020 resulted in approximately 3.0 miles of improvements to the California Central Valley Flood Protection system. The project area lies along the east bank of the Sacramento River in Sacramento. The program consists of constructing cutoff walls through existing levee embankments to remediate levee through seepage and under-seepage. Key challenges included designing and constructing measures to remediate a 100-year-old legacy levee system, the presence of both industrial and residential properties immediately adjacent to the landside of the levee creating severe space and access limitations, and performing this work during the 2020 statewide mandate to shelter-in-place due to the COVID-19 pandemic. The project team of contractors, USACE, state and local agencies, and engineering firms partnered to bring this project to successful completion within budget and on schedule expending more than 60,000 man-hours with no lost time accidents. With the issuance of future planned contracts, the program will significantly reduce flood risk to the City of Sacramento.

Sep 8, 2021

By Maurizio Siepi, Paul van Horn, John Coupland, Julian Crawley

"TTMJ is the acronym for the Slurry (Diaphragm) Wall Tension Track Milled Joint currently in development as part of the European Union's innovative and far-reaching Horizon 2020 initiative (FTI Pilot-2015-1 720579). The TTMJ Project has been specifically set up to deliver this versatile new step-forward in Slurry Wall technology. The TTMJ System is protected by patent in Europe and the USA, and is currently under development by a consortium comprising Trevi SpA (Italy), Arup (Netherlands) and CCMJ Systems (UK). The principles of the TTMJ System together with the installation process are herein described in general terms. The system is still under development with field trials scheduled for early 2018, so some of the detail will not be disclosed at this stage. It is the intention of the Authors that the results of these field trials and a more complete description of the System will be presented in a paper we intend to submit for the DFI/EFFC International Conference on Deep Foundations and Ground Improvement to be held in Rome, Italy in June 2018. The final section of this paper explains how the TTMJ system can be applied to a common application of slurry wall construction; deep circular or multi-cell shafts. The system can be used to construct shafts more easily and at less cost than current methods. It also allows shafts with smaller internal dimensions to be constructed than is currently practical.INTRODUCTIONCCMJ Systems (UK) realised that an innovative new approach to forming joints in both Slurry (Diaphragm) Walls and Secant Pile Walls would provide greatly improved joint integrity to greater depths, to the overallbenefit of retaining wall quality, across the world-wide foundations industry.In particular this new system is designed to:??Increase the effective depth range of Slurry Walls (especially walls excavated by grab) and Secant Walls??Remove the requirement for Stop-ends or Joint Formers??Allow for a Shear Key at the joint??Allow for a Water Stop to be installed at the joint??Permit Continuous Reinforcement across the joint??Optimise Reinforcement Density and hence Concrete Flow??Facilitate joints in corner panels eliminating the need for “L” shaped cages and reducing largesingle-pour concrete volumes and slurry storage capacity requirements.??Enable the construction of smaller-dimensioned square and circular deep shafts (especially useful for city-centre sites) than is possible with current methods.CCMJ Systems approached other industry specialists with a view to forming a development team to explore the possibilities for this new technique."

Jan 1, 2017

By P. Seethalakshmi, Yatakuri Yaswanth Naidu

The use of a single pile, group of piles with pile cap, piled raft foundation system, etc., are prevalent in transferring the superstructure load from the soft soil layers to the firm underground layers to reduce the settlement and improve the bearing capacity. The recent development of disconnected piled raft foundation has gained greater importance in improving the load transfer mechanism among the pile, raft, and subsoil by reducing the vulnerability of the greatest axial force on the pile head which leads to pile failure. The present study aims at analyzing the performance of unreinforced and Geogrid reinforced disconnected piled raft foundations under vertical loading using the commercially available finite element software PLAXIS-3D. A parametric study was conducted on unreinforced and reinforced disconnected piled raft foundations to explore the effect of varying pile stiffness as well as the inclusion of Geogrid layer on the load vs settlement, the load sharing ratio of piles and raft, and the distribution of axial load and bending moment along the length of the pile. The Mohr-Coulomb model was used for the granular cushion layer while the Modified Cam Clay model was used for soft clay underlain the sand layer. Raft and piles were assumed to be rigid and linear elastic. The results showed that axial force taken by piles with higher stiffness was maximum while settlement at the bottom tip of the pile with higher stiffness was maximum in both reinforced as well as unreinforced disconnected piled raft systems.

Sep 1, 2022