Search Documents

By David White

When finished (projected completion in 2016) the Hong Kong-Zhuhai-Macau Bridge Project will comprise three cable-stayed span bridges and a 4.15 mile immersed tube tunnel - linking Hong Kong to Macau and the mainland Chinese city of Zhuhai. The design included two artificial Islands to serve as the transition structures for the tunnel to bridges, entailing a massive seaborne land reclamation project, and the use of thousands of sheet piles, and man-hours. The challenges of driving individual steel sheet in 100? of water are well known, let alone in the open waters of the South China Sea. In 2010 a joint effort between American Piledriving Equipment (APE) and Allnamics Pile Testing Experts convinced the Chinese contractor First Harbor Marine Group China that a massive multi-vibro hammer can be used to drive 130? long, 72? diameter steel pipe piles weighing 662 US tons each into the sea bed of the South China Sea for the Hong Kong - Zhuhai - Macau bridge artificial islands. Combining APE?s hammer design, production and operation know-how with the pile driving simulation and installation know-how of Allnamics made it possible to show the feasibility of driving these gigantic piles into bottom of the sea to the required depth.

By David White

"When finished (projected completion in 2016) the Hong Kong-Zhuhai-Macau Bridge Project will comprise three cable-stayed span bridges and a 4.15 mile immersed tube tunnel - linking Hong Kong to Macau and the mainland Chinese city of Zhuhai. The design included two artificial Islands to serve as the transition structures for the tunnel to bridges, entailing a massive seaborne land reclamation project, and the use of thousands of sheet piles, and man-hours. The challenges of driving individual steel sheet in 100’ of water are well known, let alone in the open waters of the South China Sea.In 2010 a joint effort between American Piledriving Equipment (APE) and Allnamics Pile Testing Experts convinced the Chinese contractor First Harbor Marine Group China that a massive multi-vibro hammer can be used to drive 130’ long, 72’ diameter steel pipe piles weighing 662 US tons each into the sea bed of the South China Sea for the Hong Kong - Zhuhai - Macau bridge artificial islands. Combining APE’s hammer design, production and operation know-how with the pile driving simulation and installation know-how of Allnamics made it possible to show the feasibility of driving these gigantic piles into bottom of the sea to the required depth.INTRODUCTIONThe challenges of driving individual steel sheets in deep water are well known, let alone in the open waters of the South China Sea. Often the challenges of construction are overcome with engineering or equipment. The challenges of China’s Hong Kong-Zhuhai-Macau Bridge, on the drawing board since 1983, were to overcome both. The challenges of overcoming the skepticism of the Chinese Engineering community would be another story.The finished project will comprise three cablestayed span bridges and a 4.15 mile immersed tube tunnel linking Hong Kong on an eastern span to the China mainland cities of Zhuhai and Macau via two western spans."

Jan 1, 2017

By Bora Okumusoglu, Devon K. V. Mothersille

"AnchorTest is an innovative software package, specifically developed for tablets, that permits ground anchor test data assessment and management in real time. The solution has two components: a front-end tablet app runs on the Apple iPad platform, and a back-end Cloudbased system running on Amazon Web Services with an online cross-platform website, which can be accessed from any PC, tablet or even mobile smartphone. This tool provides full data analysis and data management capabilities and portability to create greater efficiency in the anchor testing process. AnchorTest is programmed to accommodate the major international anchor testing codes and incorporates an intuitive user interface, which is revolutionary compared to conventional engineering software designs. The use of this tool creates an environment where the testing of ground anchors has effectively become a paperless exercise with greater efficiency and access to instantaneous feedback on the performance of anchors in relation to established acceptance criteria.Historically, project personnel record and analyze the results from anchor load tests using spreadsheets and a laptop computer and/or on predesigned paperbased test sheets (usually as a backup of the testing). In addition, the processing of the test results is not typically performed in real time as the testing progresses — the calculations and analysis are performed either afterward while still on site (if a field office is available) or after returning to the office. Undoubtedly, on larger projects containing numerous anchors where multiple anchor tests may be performed at the same time, processing, analyzing and accepting the load test data and results can be especially time consuming, which could cause delays to the construction schedule.DevelopmentThe need for a more automated and digitized approach to record, process and analyze the data from anchor load tests was highlighted at a deep basement project for a mixed-use development complex in Moscow, Russia. The diaphragm wall supporting the structure was approximately 1,970 ft (600 m) in perimeter length and about 148 ft (45 m) deep, with an excavated depth of about 82 ft (25 m), which required six levels of single bore multiple anchors (SBMAs). This project provided a challenge to recording, processing and signing off on the data generated from some 3,600 3-unit SBMAs. More specifically, for this project, three hydraulically synchronized stressing jacks were used to stress and proof test each 3-unit SBMA, which resulted in nearly 10,800 data plots of the load-extension tests being generated. This project served as the main impetus in the conceptual design and optimization of AnchorTest."

Jan 1, 2017

By Maria Flessas, Justin Ray, Danielle Steinmetz, Brian Zuckerman

"The Ventura County Medical Center Hospital Replacement Wing project consists of the construction of a 2- to 3-story building with a basement encompassing the entire footprint and two corridors connecting the new hospital wing to existing buildings. The site is located in the Ventura Basin where strong ground shaking has been observed during moderate to large earthquakes on nearby faults. The upper 90 feet of the soil consists of loose to medium dense finegrained sands and low plasticity silts that are potentially susceptible to liquefaction, seismic densification, and hydroconsolidation. Ground settlement associated with a large seismic event on a nearby fault is estimated at 20 to 26 inches. To account for the anticipated ground settlement, auger pressure grouted (APG) piles gaining support below the potentially liquefiable soil were selected for the support of the proposed structure. Challenges for pile design included the anticipated earthquake-induced ground settlement, high downdrag loads, low soil lateral capacity during strong ground shaking, and the effect of pile installation on the performance of the existing adjacent buildings and the installed shoring system. The replacement hospital is supported on over 600 APG piles, with lengths varying between 120 and 140 feet. Axial pile capacities were verified with an extensive indicator pile installation program and dynamic pile load testing.INTRODUCTIONThe Hospital Replacement Wing (HRW) project is at the Ventura County Medical Center (VCMC) in Ventura County, Southern California (Figure 1). The VCMC consists of three interconnected hospital buildings (Buildings 303, 304, and Fainer Building), the Medical Laboratory/Cafeteria Building, two mental health buildings, a medical office building, an emergency generator building, and surface parking lots. The HRW is near the center of the campus, adjacent to several existing buildings.The HRW is a 2- to 3-story structure, with a 15- to 20-foot-deep basement beneath the entire 95,000-square-foot building footprint. The HRW project includes a Loading Dock, a four-level corridor to the Fainer Building (Fainer connector), and a two-level corridor to the Medical Laboratory/Cafeteria Building (Café connector). The corridors are structurally separated from the existing buildings. Typical dead plus live load column loads for the HRW range from about 635 kips to 935 kips and total loads range from about 860 kips to 1,295 kips."

Jan 1, 2016

Jan 1, 1986

By Negin Khalili-Motlagh-Kasmaei, Paul O'Leary, Christopher J. Rothsiedl, Dimitar Ninesvski, Alexander Zöhrer, Vincent Winter

This paper presents the implementation of a digital twin for the vibro-replacement ground improvement process, as part of a digital construction site. The goal is to implement an evidence-based quality assurance for each produced element (column or point). The system uses a combination of planning data and real-time machine data collected automatically from construction equipment. In addition to the quality assurance, feedback is provided in a number of areas, e.g., condition monitoring of the equipment. The digital twin builds upon the real-time sensor and machine data, fused with metadata, to implement a digital model for the process. A hierarchical data evaluation, using rule-based Key Performance Indicators (KPIs), permits viewing of the spatial variation of data over the construction site. This permits the modelling of systematic variations in subsurface properties across the site, enabling the detection of anomalous individual elements, the diagnosis of their cause and the prediction of properties as construction proceeds over the site. All time-series data and KPIs are represented by standard classes of objects, leading to a generic coding of the data analysis; this minimizes the effort required to add additional sites and/or new KPIs. Examples are presented for a number of sites, where the system was used to identify anomalous columns.

May 1, 2022

By Chu E. Ho, Paul Napoli

This paper presents the performance of nineteen open-ended steel pipe piles driven through highly variable overburden soils into glacial till and schist bedrock. The piles were 16 inches in diameter and 0.656 inches thick, with yield strength of 50 ksi. The piles were designed for a service capacity of 250 kips and were driven to achieve an ultimate geotechnical capacity of at least 500 kips. Due to the large variation in the ground conditions, installed pile lengths ranged from 25 to 66 feet. Some piles were driven to refusal on the bedrock while others were terminated at final driving resistance of 2 to 7 blows/in. Two piles were suspected to be plugged during driving while others did not. Each pile was instrumented with strain gages and accelerometers near the pile top, and observed using a Pile Driving Analyzer (PDA) to provide preliminary guidance on pile capacity achieved at end of initial drive (EOID). The influence of plugged and unplugged pile toe conditions on the interpretation of pile capacity was investigated using Case Pile Wave Analysis Program (CAPWAP). Characteristics of driving energy, compressive and tensile stresses developed in the steel pipe piles, and the resulting pile deformation behavior are discussed. INTRODUCTION The Hunters Point South redevelopment in Long Island City, Queens is one of New York City’s major efforts to transform former manufacturing zones into mixed developments for the middle-income community. The site is located along the eastern shoreline of the East River and Newtown Creek. The development included low to high-rise residential buildings, a public school and retail structures. Open spaces were created along the East River and Newtown Creek waterfronts in the form of a continuous park providing for recreational and community related activities. Waterfront structures included small park buildings, walkways and viewing platforms with the shoreline protected by revetments as part of the City’s flood mitigation strategy. The project was implemented in two phases, with completion of construction for Phase 1 in 2013 and Phase 2 in 2019. Based on available historical information, extensive reclamation took place between 1855 and 1898. After 1951, changes to the shoreline were made along the East River, including the removal of reclaimed land along the northern portion of the project site to allow for docking facilities. By 1977, these facilities had been demolished and backfilled to form the current shoreline configuration. The present site was temporarily used as a parking lot with stockpiles of fill mixed with construction demolition rubble, rip-rap and boulders of varying heights across the site. The existing ground surface varied significantly up to approximately 25 feet difference in elevation. The stockpiles were removed and the site was re-graded during final development of the project. This paper discusses the foundation design challenges due to the loose overburden soils and potential obstructions within the fill material, in particular, the issues relating to installation of open-ended steel pipe piles through the ground conditions encountered on site.

Jan 1, 2019

By Andrew Budek

"Analytical and experimental work has shown that achieving the full inelastic lateral capacity of a pile may require the formation of a plastic hinge below ground level, in the pile shaft. The confining action of soil about the pile shaft was further been shown to greatly enhance the ductility capacity of the pile. An experimental program was therefore undertaken to build in the effect of external confinement through the addition of a GFRP jacket to the subgrade plastic hinge region. Two piles were thus modified, and compared to an unjacketed pile in a test rig which simulated a subgrade moment pattern and soil confinement. The ductility achieved by the jacketed piles was found to be substantially lower than an unjacketed control specimen. Failure mode of the jacketed specimens was also undesirable, involving complete tendon rupture and sudden loss in capacity IntroductionSeismic loading of concrete pile shafts can result in a demand for inelastic response. In the case of a superstructure supported by a single pile (i.e., a pile-column forming a single-column bridge pier, in which there is no rotational restraint at the top of the pile}, a plastic hinge will form below grade, at a depth which varies with soil properties and above-grade height of the center of seismic mass.In the case of a superstructure supported by multiple piles, there is rotational restraint, and the connection will experience inelastic action first. However, development of the full lateral inelastic capacity of the pile may call for the formation of a second, subgrade plastic hinge (fig. 1 )."

Jan 1, 2005

By Onur Guvener, Kalaiarasi Vembu, C. Vipulanandan

"Installation procedure and the quality of the material used in the construction have significant effects on the behavior of the Auger Cast in Place (ACIP) piles. In this study, Installation and curing of a 760 mm (30 in.) diameter and 12 m (39 ft) long ACIP pile with a design capacity of 1140 kN (128 tons) in hard clay was investigated. Construction quality was monitored using the automated monitoring system where the volume of grout pumped and the pressures were monitored with depth. The curing of the pile was monitored using axial vibrating wire strain gages at four levels and lateral vibrating wire strain gages at two levels. The residual strain and temperature profile in the curing pile was monitored over a period of week to determine the appropriate time for load testing the pile. Axial behavior of Auger Cast in Place (ACIP) Piles in hard clay was studied using full scale load test on an instrumented pile. The load-settlement and load transfer relationships of the pile was investigated based on the load test results. Development of skin friction in the load test pile and the reaction pile was also investigated.INTRODUCTIONAugered cast-in-place piles (ACIP) are drilled foundation installed by drilling a hole with a continuous flight auger to a predetermined depth. Non-displacement Augered Cast-in-Place (ACIP) piles are increasingly used for supporting building, bridges, sound barrier walls and many other structures around the world. In an ACIP pile, depending on the soil type and rate of the auger advance, ground stresses are maintained near the value that existed before construction by using a continuous flight auger, which is never withdrawn until the cementitious material (fluid Portland cement grout) is placed by pumping the grout beneath the withdrawing auger under pressure through the hollow stem of the auger (Vipulanandan, 2005). ACIP piles are typically installed with diameters ranging from 0.3 to 1.0 m and lengths up to 30 m (Brown, 2005) although longer lengths have occasionally been installed. Comparing to the drilled shafts and driven piles of equivalent size ACIP piles can be installed more rapidly with fewer disturbances to the surroundings in favorable geological conditions. Hence the installation procedure and the quality of material used in the construction have significant effects on the behavior of ACIP piles (Vipulanandan, et al. 2007). In this paper construction quality control technique for ACIP piles was investigated. Load displacement and load transfer behavior of pile in compression and tension in hard clay was also studied. The development of side resistance in compression and tension for the load test piles and the reaction pile were also investigated."

Jan 1, 2017

By Terrence M. Carroll, Chu E. Ho, Dimitrios Niarchos

"Construction of the new extension to Terminal 4 at John F Kennedy International Airport in Queens, New York involved the application of tapered piles for foundation support. Initial design based on past load testing experience had indicated that a pile depth of 65 feet was necessary to achieve a capacity of 394 tons. However, piles with a single length of 62 feet were ordered and installed, which led to marginal performance of the piles. This paper presents the technical considerations for mitigating the situation based on a systematic review of three preliminary pile load tests and dynamic capacity measurements on the shorter piles. Consideration was given to the long term gain in capacity of tapered piles due to set up in the Glacial Sand. The observational approach to the evaluation of piling performance adopted on this project resulted in salvaging many piles which failed to comply with the specified driving criteria. It was acknowledged that a more prudent course of action was for the Contractor to have ordered more appropriate pile lengths that allowed for potential variation in soil conditions across the site. The 4.6% saving in pile material did not warrant the effort that was required to mitigate the 39% of installed piles that did not meet the specified driving criterion.INTRODUCTIONAn expansion project at John F. Kennedy International Airport in Queens, New York involved the Phase 2 extension of Concourse B at Terminal 4. The site consists of 4 to 5 feet of pavement over about 10 feet of hydraulically placed sandy fill. Below this is a layer of marsh deposit, comprising of soft organic clay and peat, up to about 11 feet thick. Beneath the marsh deposits is a deep layer of glacial sand which extends to well over 100 feet below ground. Figure 1 shows the typical subsurface profile at the site. The new structures were supported on 223 steel tapered piles. The piles consisted of a straight steel pipe 18 inches in diameter and 0.375 inches thick, with a 25 feet long tapered bottom section (diameter varying from 18 inches down to 8 inches at the pile toe). The piles were first driven to the founding depth and subsequently in-filled with concrete. The concrete strength (fc) specified was 4,500 psi and the yield strength of the steel piles (fy) was 50 ksi. Initial pile design, based on earlier experience with static pile load testing for Phase 1 development at the same terminal, indicated that a pile length of 65 feet was necessary. However, piles with a single length of 62 feet were ordered and installed by the Contractor, leading to marginal performance of the piles. This paper presents the technical considerations for the adoption of alternative pile driving criteria, based on a systematic review of the preliminary static load test results for the present site and PDA measurements obtained during pile installation, in order to accommodate the capacity of the shorter piles."

Jan 1, 2017

By Peter Middendorp, Gerald E. H. Verbeek

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

Jan 1, 2005

By Brian D. Barkauskas, Terence P. Holman

A major combined nuclear and coal-fired power plant, located in on the western coast of Florida has undergone multiple upgrades in recent years to increase power output and enhance environmental controls. Construction of new elements within the existing plant structure required working in highly congested conditions and heavy crane lifts with large picking radii. The largest crane pick involved the use of an 1800 metric tonne capacity Mammoet PTC ring crane for a single long-radius, high altitude lift of a precipitator unit. Original bid tender documents had called for drilled shaft foundation support, but the presence of many critical utilities and unfavorable access for cost effective construction led specialty contractor Moretrench American Corporation to propose an alternate micropile foundation on the basis that high capacities could be achieved in the weak limestone geology and that the smaller size of micropiles would allow for more surgical installation in the utility-congested areas. This case history describes the design and construction of seventy three (73) high capacity micropiles for the value engineering alternative and the crane foundation for this critical lift. Each micropile was founded in a competent dolomitic fossiliferous limestone unit at typical depths of 23 m below existing ground surface. Strain gauge instrumented load testing was used to validate the geotechnical design parameters in the weak limestone bedrock and resulted in the finding that the entire test load was being carried in the upper half of the bond zone. Construction of the production micropiles required numerous relocations due to utility conflicts and local reanalysis and redesign of the 1.2 m thick reinforced concrete ring beam cap. Crane foundation performance was satisfactory and the effective life of this temporary foundation was only 6 months before decommissioning and demolition.

Jan 1, 2017

By Ronald Damen, Dion Denes

"Friction fatigue is the loss of soil-pile friction around the shaft area of the pile. It has been observed during impact driving of piles, and has been modelled to a limited degree using physical scale models. This paper proposes the use of high strain dynamic pile testing to assess and quantify friction fatigue in impact driven piles. The method is applied to two case studies: one on a project off the north-west coast of Australia and one on a South Pacific Island. On both sites calcareous sand layers are present. Pile Driving Analyzer (PDA) monitoring has been conducted during impact driving of steel piles, which allowed for assessment of shaft resistance development both with depth and with progressive driving, by use of wave equation signal matching. Lessons are drawn from the case studies to improve future observations.INTRODUCTIONFriction fatigue is the loss of soil-pile friction around the shaft area of the pile, under cyclic loading or during pile driving. The phenomenon has been frequently observed in some non-silica sands, such as pumice sands and calcareous sands and has been the subject of academic study.The occurrence of friction fatigue impacts the driving behaviour of piles and the shaft friction component of the ultimate geotechnical strength (Rd,ug). If potential friction fatigue is not recognised in the design phase of a project, required pile toe levels can be significantly underestimated. This could lead to extra cost and delays, or, if no adequate pile verification is conducted, to geotechnical failure or underperformance of piles. This is especially true in remote locations, such as Pacific islands, where calcareous material is often present.A better understanding of the phenomenon would aid both pile design and driveability assessment. This paper proposes the use of high strain dynamic pile testing to assess and quantify the effect of friction fatigue from impact driving. Two case studies are presented in which high strain dynamic testing has been conducted on driven piles in calcareous sands to illustrate the method.BACKGROUNDFriction fatigueThe geotechnical strength of piles is composed of the resistance to static loading by the base of the pile and the shear resistance between the shaft of the pile and the adjacent soil. The latter is often referred to as the shaft resistance or shaft friction.During impact pile driving, a decrease in shaft resistance is often observed. Although this phenomenon is also observed during vibratory pile installation, this paper deals predominantly with impact driving. This decrease in material strength from the tip of the pile influences the shaft resistance and may be either temporary or permanent. Temporary reduction in shaft resistance is common in cohesive soils and is thought to be caused by excess pore water pressure, which has insufficient time to dissipate. This phenomenon, commonly referred to as set up, is observed to a significantly lesser extent in non-cohesive materials such as clean sands (Rausche et al., 2004)."

Jan 1, 1900

By Abid Adekunte

"Engineers and developers have witnessed the growing popularity of deep basement structures as components of urban commercial and residential developments. This is often attributed to inadequate surface parking facilities in urban centres and a somewhat popular belief that underground parking facilities improve both commercial and aesthetic values of urban structures. For many years, diaphragm walls and sheet pile walls have been widely accepted as effective deep excavation support systems for basement construction in urbanised zones. However, these are now being replaced by bored pile retaining walls as preferred earth retention systems of choice on many projects for several reasons, which may include economy, faster installation process, reduced space requirement for machinery and ancillary equipment, flexural rigidity and axial capacities.However, there are complexities associated with the use of bored pile retaining walls on urban developments. These include; limitations due to vertical and horizontal installation tolerances, which is a major issue when wall is required to provide groundwater cut-off for multi-level basements as tolerances are difficult to achieve for deep piles, uncertainty associated with the prediction of wall axial capacity as piles are rarely tested, difficulties in using temporary props as wall restraint due to restricted working spaces in urbanised zones and difficulties in adopting ground anchors as restraint due to the existence of adjacent sensitive structures in built-up areas. Such complexities have resulted in cases of failure, non-serviceability and abandonment of basement construction schemes. Therefore, overcoming the intricacies associated with the application of bored pile walls is becoming a priority to the present day basement engineer.This paper is centred on the numerical modelling, design, construction and monitoring aspects of four recent case histories of multi-level basement and marine engineering construction schemes in the United Kingdom and the Republic of Ireland, which involved the use of bored pile retaining walls. The paper highlights the various customised approaches and innovative novel solutions adopted on the sites, to mitigate risks and ultimately overcome the intricacies associated with the earth retention techniques. Simple empirical equations for developing the geometry of secant pile walls for effective groundwater cut-off are presented and validated. An alternative approach for predicting axial capacities of bored pile walls is also presented; this is shown to be considerably less conservative than a common routine design approach, while also in good agreement with observations made in a recent series of laboratory-based scale model tests."

Jan 1, 2017

Jan 1, 2004

By Christophe H. Locussol

D.C. United, the professional soccer team located in Washington, D.C., completed a 20,000 seat capacity stadium in July 2018 named Audi Field. The project initially considered a foundation system consisting of roughly 800 prestressed concrete driven piles configured in groups with pile caps. A value engineering alternative proposed in a design-build manner ultimately resulted in the use of 300 single element Auger Cast Piles (ACPs) for the foundation system. The ACPs ranged between 1.5 ft and 4 ft in diameter, were up to 85 ft in length, and were connected through a system of grade beams to accommodate large lateral induced loads. Limitations in conventional analytical methods were encountered during the structural design of the piles due to the complexity of the lateral loading and pile fixity conditions. An innovative approach using advanced finite element modeling that incorporated the framing effects of the grade beams was required to meet the strict movement criteria despite large lateral loads.

By O. Craciun, C. A. Bridges, M. Cai, J. Sugawara

There are a number of methods that can be adopted for predicting the ultimate lateral resistance of a free-head rigid pile, from the conventional Brinch Hansen and Broms solutions to three-dimensional finite element analyses. Often these methods give rise to significantly different pile ultimate lateral capacities which could lead to either unsafe or too conservative designs. It is also well known that finding a rigorous and practical solution is challenging due to the complex three dimensional and nonlinear soil-structure interaction. This paper reviews some of the most common methods and produces results of pile ultimate lateral capacities embedded in cohesive or cohesionless soils. Subsequently, a finite element analysis is performed using PLAXIS 3D modelling under the same design conditions. Based on comparison of results, limitations and advantages are highlighted, and the most suitable method is proposed from a practical point of view.

Nov 1, 2022

"1.0 INTRODUCTIONThese Guidelines reflect the state-of-the-practice of the Deep Mixing Method (DMM) in North America. DMM is an in situ mixing process that breaks down the soil structure; injects binders, fillers and reagents into the soil; and blends them with the soil. DMM is also commonly referred to as Soil Mixing. The final properties of the treated soil in situ are a function of the composition of the native soils and groundwater, the binders introduced, the mixing methods and energy, and the conditions and time of curing. Treated soils generally have increased strength and stiffness and/or reduced permeability relative to the native soils.This document addresses DMM performed by rotating single and multiple axis mixing tools, rotating cutter wheels at the end of a rigid kelly bar, or trench mixing using a rotating cutting/mixing chain around the perimeter of a rigid bar. Binder may be injected through low or high energy (velocity) jets.The treated soils created through wet DMM are heterogeneous mixtures of binder, water, soil, and groundwater. Treated soils produced by dry DMM techniques are a mixture of binder, soil, and the water already present in the native soil.DMM applications described in this document include•,Earth retention•,Liquefaction mitigation•,Groundwater seepage control and containment isolation•,Bearing capacity improvement•,Deep foundations•,Mass stabilization and contamination containment•,Embankment, levee and dam strengthening, and stabilization•,Casing replacementThis document was developed to address deep foundations applications. Use of deep mixing for seepage control is not specifically addressed. The reader is referred to documents prepared by the U.S. Army Corps of Engineers for additional information. Shallow soil mixing and the use of DMM for stabilization/solidification of contaminated soils performed at depths less than 10 feet (3 m) are mentioned briefly. Jet grouting is not covered by these guidelines."

Jan 1, 2016

By Riad Diab

In 2018 the Caisse de Dépôt et Placement du Québec (CDPQ) awarded a $6.3 billion (U.S. dollars) design-build contract to the Joint Venture (JV) team NouvLR for the design and construction of one of the largest automated transportation systems in the world, called the Réseau express métropolitain (REM). The REM project is a 67 km (41.6 mi) light rail system with 26 stations linking downtown, the airport and the greater Montreal area in Canada. Out of the 67 km (41.6 mi) network, over 25 km (15.5 mi) is being constructed on a 650- span elevated structure founded on single drilled shafts socketed into rock. Optimizing the design of the drilled shafts was one of the main objectives of the geotechnical team, as it would likely result in shorter shafts that help significantly reduce the project costs. As part of the optimization process, three static axial load tests and two fully instrumented lateral load tests were performed, during the preliminary design phase, on sacrificial shafts to simulate the ultimate load level and validate construction procedures.

May 1, 2022

By Patrick van der Schaaf

"During 2016, foundation piling works were completed to allow for the construction of a production and storage/handling terminal in Rotterdam. It is there that steel foundations will be produced for offshore wind farms and the oil and gas industry. Several Dutch contracting companies were involved in constructing: foundations for an assembly hall, a barge quay and a deep-sea quay wall. For the hall foundations, cast in situ concrete vibro piles were created. Open ended steel casing piles were also installed due to very high cone resistances which made it impossible to perform cast in situ piles in certain areas. The quay wall was constructed with open ended steel casing piles in combination with sheet piles. A deep-sea quay wall was also constructed to provide enough storage area for the offshore mono piles. This project was unique and challenging due to the use of different foundation technologies in challenging circumstances and soil conditions. This paper will give an insight into the Dutch use of varying foundation piling techniques for deep-sea quay wall constructions. It can be concluded that even experienced local contractors can be surprised by variations in soil conditions. It will also show how the contractors adapted to the difficult circumstances.PROJECT OUTLINEThe project consisted of a barge quay near the assembly hall with a length of 500 metres, width of 42 metres and a height of 35 metres, and a deep-sea quay wall 480 metres in length. This paper concentrates on the foundation works for the construction of the deep-sea quay wall. The construction of the deep-sea quay wall consisted of a combination of open ended steel casing piles with a diameter of Ø 1420 mm and a wall thickness varying between 21 and 23 mm. The lengths of the steel casing piles varied between 32 and 37 metres. Between the steel casing piles triple PU 28 sheet piles were installed with lengths varying between 26 and 29 metres. In the Netherlands, a combination of open ended steel piles and sheet piles is known as a “combi wall”. For the deep-sea quay wall a steel combi wall was shored with steel H- section profiles that were driven in a raked position whilst being injected with grout, so called MV-piles. The MV piles for this project consisted of steel HEB 600 sections with lengths from 52 up to 59 metres and were installed with angles varying between 42.5 and 47.5 degrees. For a detailed overview regarding the project specifications reference is made to table 1 which is presented below."

Jan 1, 1900