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By Vijay Kumar, Serhat Baycan, Karsten Beckhans

For the deep foundation of podium and tower of the Kuala Lumpur City Centre, BAUER (MALAYSIA) SDN. BHD. constructed 225 bored piles with diameter range of 2.0 to 2.5 m. In order to comply with the depth requirement of the design, for planning purposes and preparation for site, the drilling equipment was required to achieve a maximum drilling depth of 150 m. Actual piles constructed on site were deeper than 120 m. These dimensions caused superlative challenges which included but were not limited to; controlling the open hole stability over time with polymer, installing 70-ton heavy steel cages, pouring up to 550 m³ concrete continuously, in conjunction with installation of kingposts into workable, fresh concrete. The piling works were executed with a BG 72, the biggest drilling rig globally available, and the stringent verticality of the pile bore holes which required approval prior to cage installation. For verification of verticality, Bauer’s patented Drilling Inclination System was successfully used.

Nov 1, 2022

By Lu Yitan, Frances Badelow, Manish Tiwari

"Large ‘design and construct’ projects often present significant geotechnical risks. However, these also present significant opportunities for value engineering in design. These opportunities can be realised through systematic site investigation and close collaboration with the Contractor to dovetail the design solutions to suit construction methods. This paper presents a case study of a large infrastructure project in Singapore which involved design optimization of an earth retention system for a deep excavation in a constrained urban environment. The project also required installation of over one thousand bored piles in highly variable ground conditions - identified as a key risk. Systematic site investigation was undertaken to develop a reliable ground model. A detailed value engineering exercise identified opportunities for design optimization by changing the retention systems and construction sequence in some segments. An innovative low cost ground improvement method was used in some areas to reduce the forces on the retention system. An extensive instrumentation and monitoring plan was implemented for verification of design and to mitigate the remaining risks. This paper includes the lessons learnt on this challenging project, which are relevant to a wide range of construction projects.INTRODUCTIONSingapore has been rapidly expanding its underground Mass Rapid Transit (MRT) network over the past two decades. The Thomson-East Coast Line (TEL) forms part of this expansion and is 43 km long and fully underground comprising 31 stations. This paper describes the value engineering and design optimizations undertaken during detailed design of the earth retaining and support structures (ERSS) for one of the underground stations along TEL. The station, currently under construction, is up to 24m deep and 350m long. The edge of the station excavation is less than 10m away from the existing MRTviaduct. The proposed station is surrounded by high-rise residential and commercial structures, somewithin 2m of the excavation. Land Transport Authority (LTA) of Singapore imposes stringent technical and contractual requirements on MRT construction works to ensure high quality and safety standards. These include minimum requirements for embedment of retaining walls, groundwater control, additional site investigation, instrumentation and monitoring, and compliance to LTA’s Civil Design Criteria (CDC). Any deviations from the minimum requirements can only be approved by LTA after detailed calculations, analysis and field testing are completed and additional monitoring and control measures are proposed."

Jan 1, 1900

By Y. C. Han

The advances in seismic design considering soil-structure interaction or soil-pile-structure interaction are described using a substructure approach. The nonlinearity of soil is considered approximately using a boundary zone model with non-reflective interface, and computer programs are available for practical applications. The validation of model is confirmed with dynamic tests on piles in the field, and the results for a single pile are used to compare with the predictions in this study. The liquefaction for sand soil layer can be accounted for, and a case of liquefaction is discussed. Two practical examples are examined, a vacuum tower structure supported on foundation of steel pile group and a table top structure supported on foundation of concrete pile group. To illustrate the effects of soil-pile-structure interaction on the seismic response of vacuum structure, different base conditions are considered, rigid base, i.e. no deformation of the foundation; linear soil-pile system; and nonlinear soil-pile system. The method introduced can be applied to the design of tall buildings, bridges, industrial structures and offshore platforms with soil-pile-structure interaction under seismic or dynamic loads.

Jan 1, 2010

By Mohamed Mekkawy, William W. Wheaton, Ira Brotman

"The Virginia Port Authority and the U.S. Army Corps of Engineers are partnering to construct the Craney Island Eastward Expansion (CIEE) to meet the dual purpose of extending the life of Craney Island as a dredged material management area and providing land for a state-of-the-art marine terminal. The over 500-acre (200-hectare) expansion provides additional upland dredged material capacity for the Hampton Roads Harbor by constructing perimeter dikes, that once filled, will provide land for the development of a container terminal. In the winter of 2010/2011 the first stage of sand fill was placed, followed by the installation of approximately 12 million linear feet (MLF) (3.6 million linear meters, MLM) of marine PVDs. With over 36 MLF (10.9 MLM) of PVD required to complete dike construction the project will be one of the largest PVD installation project in the U.S.This paper details the challenges associated with the construction of the cross dikes, in particular the design, testing, installation and monitoring of prefabricated vertical drains (PVDs) installed overwater to depths of over 130 feet (40 meters) for foundation improvement in the insitu very soft Norfolk Clay. With expected settlements of 20–30 ft (7-10 m) and 30 percent average strains, the discharge capacity of the PVDs was of particular concern. Laboratory data is presented showing the magnitudes and variability of discharge capacity under different confining pressures in both a straight and buckled condition.The method of installation and monitoring of the marine PVDs in open water included developing a specialized barge and sophisticated positioning and data collection system to verify installation location, depth of penetration and track quantities. An observational method, including material testing, detailed surveys, periodic in-situ testing, and instrumentation, was utilized by the project team to assess the project’s progress and allow for validation of consolidation and strength gain rates and magnitudes."

Jan 1, 2017

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

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

Jan 1, 2017

By George Filz, Morales, Carlos, Bertero, Filippo Maria, Alessandro, Leoni

"The Deep Mixing Method (DMM) represents a viable solution to improve adverse geotechnical properties of foundation soils for many practical applications. A pre-construction soil investigation campaign is necessary to assess soil properties and to retrieve samples of different soil layers for a laboratory Bench Scale Testing program (BST). The BST has to be designed using various binder types, binder contents, and water/cement ratios in each of the soil types. Following the laboratory program, a full scale Field Test (FT) is typically necessary to verify the results of the BST. This paper will highlight the differences and the importance of performing both pre-construction laboratory tests and field tests to ascertain the proper mixing parameters in the different soil layers. Comparative analyses and interpretations between the lab and field stages, along with accumulated information about soil properties and quality control (QC) results, allow fine-tuning the production parameters throughout a project. Three Deep Mixing Method projects, where both laboratory and field tests were executed, are illustrated: (1) The LPV 111 Project (New Orleans, LA, USA): DMM was used for ground improvement/foundation strengthening to stabilize and support the burden of a new levee raise; (2) The Rio Puerto Nuevo Project (San Juan, PR, USA): DMM was applied to improve the soils adjacent to a 90"" forced sewer main relocation and to improve the soils for the base of a new drainage channel; and (3) State Road 83 (US 331) over Choctawhatchee Bay project (Walton County, FL, USA): DMM was applied to stabilize the causeway sections of the bridge enhancement project. Data recorded during laboratory and field tests for these projects were analyzed and interpreted to select the most appropriate construction parameters to provide a final high-quality product.INTRODUCTIONThe Deep Mixing Method (DMM) represents a viable solution to improve adverse geotechnical properties of foundation soils in many situations. The effectiveness of working parameters depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product.Generally a pre-construction soil investigation campaign has to be performed to assess soil properties and to retrieve samples of different soil layers for the laboratory Bench Scale Testing programme (BST). The BST has to be designed using various binder types, binder contents (or cement factors - CF), and grout water/cement ratios (W/C) in each of the soil types; the selection of the different combinations and dosages for the BST is based on past extensive experiences on similar materials. Following the laboratory programme results, a full scale Field Test (FT) has to be designed and executed, installing several DMM elements to verify the results of the BST and fine tune the construction parameters, with the appropriate binder type and dosage and the most effective equipment and tool configuration."

Jan 1, 2015

By Ira Brotman

The Virginia Port Authority and the U.S. Army Corps of Engineers are partnering to construct the Craney Island Eastward Expansion (CIEE) to meet the dual purpose of extending the life of Craney Island as a dredged material management area and providing land for a state-of-the-art marine terminal. The over 500-acre (200-hectare) expansion provides additional upland dredged material capacity for the Hampton Roads Harbor by constructing perimeter dikes, that once filled, will provide land for the development of a container terminal. In the winter of 2010/2011 the first stage of sand fill was placed, followed by the installation of approximately 12 million linear feet (MLF) (3.6 million linear meters, MLM) of marine PVDs. With over 36 MLF (10.9 MLM) of PVD required to complete dike construction the project will be one of the largest PVD installation project in the U.S. his paper details the challenges associated with the construction of the cross dikes, in particular the design, testing, installation and monitoring of prefabricated vertical drains (PVDs) installed overwater to depths of over 130 feet (40 meters) for foundation improvement in the insitu very soft Norfolk Clay. With expected settlements of 20?30 ft (7-10 m) and 30 percent average strains, the discharge capacity of the PVDs was of particular concern. Laboratory data is presented showing the magnitudes and variability of discharge capacity under different confining pressures in both a straight and buckled condition. The method of installation and monitoring of the marine PVDs in open water included developing a specialized barge and sophisticated positioning and data collection system to verify installation location, depth of penetration and track quantities. An observational method, including material testing, detailed surveys, periodic in-situ testing, and instrumentation, was utilized by the project team to assess the project?s progress and allow for validation of consolidation and strength gain rates and magnitudes.

By Alan B. Wagner

Data from seven instrumented pile load tests in Milwaukee, Wisconsin and two other instrumented load tests reported in the literature, one in Evanston, Illinois and one in Houston, Texas were reviewed. The data were for pipe piles having diameters from 9-5/8 inches to 18 inches, driven to depths between 36 and 96 feet. These data were used to develop a relationship between effective vertical stress and unit side friction and unit end bearing. These relationships were based on readily measured soil parameters, undrained shear strength, Cu, and Standard Penetration Test (SPT) values. This Beta (ß) and Nt approach and four other methods were then used to calculate the bearing capacity of the nine cases analyzed. The results from each of the methods are compared with the measured results.

Jan 1, 1991

By Timothy Nelson, Simon Burnworth

"The University of California’s new Berkeley Art Museum and Pacific Film Archive will showcase a collection of art and film in a facility that pairs an existing 1930s-era printing press facility with a new, architecturally unique auditorium wing. The centerpiece of this adaptive-reuse project is the existing 3- story art-deco Administrative Building, which will be integrated into the new museum and provide approximately 18,000 square feet of usable space. Degenkolb Engineers, as the shoring engineer of record, along with Condon Johnson & Associates Inc., the shoring contractor, worked together with general contractor Plant Construction Company to design and build a temporary structure to facilitate the complex retrofit, renovation, and expansion of the Admin Building. This paper will discuss the challenges faced by the design and construction team, the sustainable solutions implemented on the project, and the collaboration between teams to meet the unique constraints of the project and the site.INTRODUCTION AND PROJECT BACKGROUNDThe Berkeley Art Museum and Pacific Film Archive (BAMPFA), which currently resides in a 1970s-era post-modern concrete structure just south of the University of California Berkeley (UCB) campus, was in need of a new home after an engineering evaluation revealed that the building possessed seismic deficiencies. Pressed for space, the University looked within its portfolio of properties and identified the site of the former University Printing Press facility as the place to build BAMPFA’s new home."

Jan 1, 2017

By Shaw-Shong Liew

This paper presents the processes of investigation, analysis, design, construction and monitoring of soil nail stabilisation work to facilitate a 14.5 m deep excavation at an uncontrolled fill ground. An extensive instrumentation programme had been implemented to monitor the performance of the stabilisation solution, to provide validation for the designed nail resistance and groundwater variation. From the monitoring results, it was proved that the soil nail stabilisation technique is effective for loose saturated fill provided that substantial care is taken during implementation. Construction difficulties, solutions to overcome the problems and lessons learned will be discussed in the paper.

Jan 1, 2006

By Lisa R. Papandrea, David Chen, Walter E. Kaeck

"Construction of the University at Buffalo’s new School of Medicine and Biomedical Sciences (UB-SMBS) required excavation in variable ground to a depth of more than 40 ft adjacent to the NFTA Metro subway and Allen Street Station. Complicating the building design and construction, the new medical facility incorporates the at grade Station entrance building, requiring a combination of temporary and permanent excavation support structures, a complex sequence of ground support installation, and a mix of shallow and deep foundations to accommodate the large floor spans and concentrated column loads introduced by building over and adjacent to the Station entrance. Excavation and foundation construction was challenged by a stratified soil profile with interlayered and sensitive sands, silts and clays and complicated groundwater regime with perched and regional water tables. Efficient construction required ongoing coordination between the design team and contractor, careful field observation, and construction monitoring in several facets of below grade construction. This paper describes the design and construction of excavation support structures and foundations to manage the variable ground, congested site conditions, and complications of building adjacent and above an active subway station. Use of site instrumentation and monitoring data to provide guidance in construction when unanticipated field conditions arise is illustrated. Lessons learned in installation and sequencing of excavation support, groundwater control and foundation construction are also discussed.INTRODUCTIONUniversity at Buffalo President Satish K. Tripathi heralded the new School of Medicine and Biomedical Sciences (UB-SMBS) as a future linchpin of UB’s downtown campus that will revitalize the area and enhance western New York’s emerging bio-sciences corridor. The $375 Million, 628,000 square foot, eight story building with two basements is expected to house 2,000 faculty, student and staff allowing UB to increase class size from 140 to 180 students. It will be constructed above the Niagara Frontier Transportation Authority’s (NFTA) Allen Street Station, creating a direct connection to Buffalo’s light rail system. The 200 ft x 400 ft site is bounded by Main Street, High Street, Washington Street and the Roosevelt Apartments and adjoining parking lot at the west, north, east and south respectively, as shown in Figure 2. Groundbreaking for the new building was in October 2013 with the facility scheduled to open in early 2017."

Jan 1, 2016

By Filippo Maria Leoni, Alessandro Bertero, Gianluca Pianezze

"As part of the Southeast Louisiana (SELA) drainage program, designed by the U.S. Army Corps of Engineers (USACE) to reduce flood damages in the City of New Orleans and surrounding parishes through the construction of new pumping stations and better drainage canals, the SELA-22 project entailed the installation of a concrete covered canal along Jefferson Ave. and Prytania Street, in a highly urbanized portion of Uptown New Orleans, LA. The scope of the required soil improvement was to replace the soil between two parallel lines of sheet piles with a soil-cement mass to eliminate underseepage and provide structural support for the concrete culvert. The USACE selected the jet grouting (Jet Grout) technology for the construction of the bottom plug. The bottom plug is between 18 and 21.5 ft thick with a maximum depth of approximately 40 ft, for a total length of approximately one mile. The treated soil comprised soft clays and silts with occasional presence of sands. Project specifications required 100% area coverage, a 28-days unconfined compressive strength of 100 psi and hydraulic conductivity of 1x10-6 cm/s, to be verified by testing specimens from cored samples. The specialty geotechnical contractor proposed to accomplish the task utilizing their proprietary and innovative elliptical bi-fluid Jet Grout technology, and elected to perform a pre-construction bench scale laboratory mixing program to determine the most suitable grout mix features (i.e. binder type and proportions, binder content, etc.) to be applied in the subsequent field test and production stages. This paper will summarize and compare the results obtained from the different pre-construction and construction stages; interpretations of the data will be provided, along with general considerations regarding the effectiveness and significance of bench scale testing for jet grouting applications.INTRODUCTIONIn general, the effectiveness of the construction parameters in any ground improvement work depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product."

Jan 1, 2016

By Rob Jameson

"Although seismic retrofit is recognized as a key micropile application, widely-used reference documents do not clearly address design and testing recommendations for micropiles that are loaded primarily under seismic conditions. The principles of micropile design and construction and their application to seismic retrofit projects are well understood and executed by leaders in the field. As the micropiling market grows, a wider audience relies on the information presented by DFI and similar industry groups. State-of-practice updates appear periodically in conference proceedings, but examination of recent bid documents makes it clear that there are opportunities to improve the specification of load, deflection, testing and acceptance criteria on many seismic retrofit projects. Updates to the FHWA Manual or DFI Sample Specification that specifically address seismic retrofit cases would be useful tools to disseminate information and enhance the state of practice.Micropile Survey UnderwayAs one step in this process, I am distributing surveys to contractors and designers prior to DFI Super Pile ’09 (June 4-6, San Francisco) seeking recommendations for design and testing procedures applicable to seismically loaded micropiles. I am also requesting any existing references that could be promoted as a standard for these cases. Anyone interested in participating in this survey, should contact me at rjameson@malcolmdrilling.com. Seismic RetrofittingMicropiles are ideally suited to seismic retrofit applications. Their high-tensile and compressive capacity can sustain the large concentrated loads induced during seismic events. They can be installed within and around the access limitations of existing structures, and can be drilled through and grouted into the wide variety of soil and rock materials encountered in seismically active zones.Seismic retrofits have included micropiles since the early 1990s, and they are now widely specified in the Western U.S. In the San Francisco Bay Area alone, thousands of micropiles have been installed for seismic upgrades of highway and transit aerial structures, and retrofits of commercial, residential and public buildings. Micropile use is growing in both public and private sectors, with large-scale retrofit projects currently underway for both the Bay Area Rapid Transit (BART) system-wide upgrades and renovations at San Francisco Airport."

Jan 1, 2009

By Z. Q. Zhou

It is the first worke in design of pile foundation to determine the carring capacity of single pile, and a static loading on site is considered to be the lost derect and reliable way. All values P and settlements S induced can be plotted as a broken-line. Since soil is a kind of elasto-plastic and cohesive material, the increasing of settlements is generally greater than that of loads. Different value Pu nay be given by different tester on his P-S diagram, because of erroys in the test and complicated, characteristics of soil. The analytical method of exponential equation shown in this paper derives a specified solution. After using an exponential curve to regress values of loads P and corresponding settlements S from on-site test, coeficients A and B of exponential equation can be obtained. With this curve an ultimate carrying capacity of single pile can be determined. The resistant forces of pile shaft and pile tip can also be defined by the tangent of the calculated knee point, as it is called (tangent method). At last, an example is given to show how the ultimate carrying capacity of f 500mm bored pile is obtained with this method for a project in Kunming.

Jan 1, 2010

By P. Kiruthika, A. Murali Krishna

Soil liquefaction is a dangerous phenomenon that involves huge damages during strong earthquake ground motion event. Stone columns (SCs) are widely used as liquefaction mitigation element which is expected to perform the improvements against liquefaction hazard by densifying, increasing the stiffness and rapid dissipation of excess pore water pressure in the surrounding soil. Although in the recent times few studies on the behaviour of stone columns in the seismic zone has evolved, the performance of SCs in the multi-layered soils is not extensively examined. This paper presents the numerical investigations on the performance of SCs installed in the multi-layered soils as a liquefaction mitigation measure against the seismic loading. The acceleration time histories, Excess Porewater Pressure (EPP), vertical displacement and stress ratio evaluated along different depths using PLAXIS 2D. With the installation of stone column there is a considerable reduction in the acceleration amplitude, which in turn reduces the EPP and vertical displacement at different locations and the amplitude of reduction depends on the soil stiffness levels at the depth.

Sep 1, 2022

By Takefumi Takuma, Hiroyuki Nishimura, Shigeru Kambe

"In order to achieve tubular pile driving with low noise and low vibration, the Press-in Piling Method has been adopted on many projects. The method utilizes reaction force derived primarily from previously driven piles to push in the next pile into ground. With attachments, the Press-in piling equipment can deal with hard soil as well as difficult site conditions. At West Toronto Diamond Rail Grade Separation Project in Toronto, Canada, the Press-in piling equipment drove more than 500 of 914 mm (36 inches) diameter tube piles in length of 12 to 25 meters (39 to 82 feet) to construct earth-retaining walls for railway grade separation. Myoshoji River Restoration Project in Tokyo, Japan drove some 600 of 1,000mm (39.4 inches) diameter tube pipe sections in length of 11 to 22 meters (36 to 72 feet) by the rotary Press-in piling equipment to increase the flood drainage capacity of an existing river in highly populated area of the city. Both projects exemplify the advantages of the method in urban settings.1. BACKGROUNDThe Press-in Piling Method was invented some forty years ago in Japan, where a very large number of construction projects were causing widespread construction pollution, especially by pile driving work in densely populated areas. The method has been providing solutions for piling projects which could not have been built otherwise due to the noise and vibration impact to the surrounding communities. The method can be used with various types of piles including sheet piles, tubular piles, concrete sheet piles and so on. With high pressure water jet and continuous flight auger attachments, the Press-in piling equipment can deal with dense sand, stiff clay, gravels, boulders and even soft rock without employing a different set of equipment."

Jan 1, 2015

By Damien Enright, Franz-Werner Gerressen

CFA/ACIP pile is the most used single pass drilling method for deep foundation installations. It is constructed by rotating and driving a Continuous Flight Auger (CFA) into the ground at a controlled speed to the specified pile depth. Concrete is then pumped under continuous positive pressure through the hollow stem of the auger to fill the borehole as the auger is withdrawn. CFA/ACIP piles are preferred due to their high daily production capacity when used in suitable soil conditions. CFA/ACIP piles have been installed in the United States for decades and the industry has seen a huge development in equipment, installation process, monitoring and more. Nowadays, CFA/ACIP piles are installed using fully computer monitored drill rigs rather than a bulky crane and lead setup. Because of the torque and crowd offered by these rigs, piles can be installed to depths of more than 100 feet and diameters up to 48 inches. New age crane-based equipment with leader systems are than welcome to substitute old fashioned bulky cranes These new age crane-based systems combine the benefits of sufficient hydraulic power, fully equipped software, etc. with the additional benefits that they can do single pass drilling without extension systems, even when drill depths of more than 100 feet are required. The paper will explain the construction process and will discuss some jobsite references and experiences made using the new age crane-based equipment.

Oct 1, 2022

By Brian P. Waagner

Construction law in general and the law of deep foundations in particular continues to develop rapidly, particularly in the areas of risk allocation. Public and private owners are increasingly using contractual disclaimers to shift the risk of differing site conditions to contractors, and courts are increasingly willing to enforce these contractual devices. Perhaps also in an effort to control costs, public and private owners are turning to design-build contracting techniques. While design-build offers many advantages over traditional project delivery systems, it does not answer all of the risk-allocation questions that frequently arise. Even in design-build, problems with unanticipated subsurface conditions and defective design are not easily addressed. Finally, developments in electronic commerce present the potential to transform the construction industry.

Jan 1, 2002

By Joram M. Amir, Ernst Niederleithinger, Nikolaus Schneider

"Abstract: Diaphragm walls are used to provide a stable and watertight confinement for the construction of tunnels, underground railway stations, deep basements and other structures requiring deep excavations. Water seepage and soil loss through the joints have occurred on several occasions, causing extensive damage. This may have been due to uncontrolled concrete flow between the joints, unexpected geologic conditions or just poor workmanship.Different ways of quality assurance are applied on construction sites. Most of them rely on recording parameters of the construction equipment and conventional concrete quality control. In the frame of the EUREKA/ZIM project DiWaQ we have looked at several ways to perform non-destructive quality control. Some methods are to be applied after excavation before concreting (phase 1); others after the wall is completed (phase 2).For phase 1 we have used two different principles for checking the shape of the excavation, especially the joint to existing panels. A mechanical device which can be adapted to the excavating equipment was developed; field tested and validated on test and construction sites. It is described in detail in another paper in the same volume. A sonar-based device with a 10 mm resolution has shown good performance in the lab, but is still under development.For phase 2 different temperature sensors have been lowered into access holes to monitor the hydration heat developed during concrete curing. The same tubes can also be used to perform electromagnetic and ultrasonic crosshole measurements across or along joints to detect flaws. Especially the ultrasonic method has shown promising results on validation specimen at the BAM test site at Horstwalde, but limitations as well. Success substantially depended on the joint type, flaw size and distance of the sensors to the joint."

Jan 1, 2014

By Rakam Lama Tamang, Michael J. Byle, Stephen Ernst

"For various reasons, dredging may become necessary in front of existing bulkhead walls, either for channel deepening or for environmental remediation of contaminated sediments. The removal of sediments at the base of bulkhead walls removes support for the toe of the wall that must be assessed. Evaluation of this impact can be problematic for aging bulkheads for which no design or construction records exist. This paper will address the steps that should be taken in investigation and analysis to assure proper assessment and means to address uncertainties and gaps in information. The steps include pre-investigation data review, field inspection, geotechnical and geophysical investigation tools, parametric analysis and design tools. Examples from several bulkhead assessment projects will be provided that include a variety of conditions and tools for application. The focus of the paper will be on the integration of technologies to assess bulkhead geometry, geotechnical properties and stability, structural safety and constructability issues with removal of support, and means of temporary and permanent stabilization for environmental applications.IntroductionBulkheads and quays have existed as long as there have been waterfront activities. Some of the earliest date back to 1200 B.C.E.(Raban, 1987), however in the United States few predate the eighteenth century. Most extant bulkhead structures, and all steel sheet pile bulkhead walls date from the early 20th century or later. These structures function to protect the shore from erosion, support landside activities, and serve as place to moor and offload vessels. Regardless of the age or usage of existing bulkheads, it is essential to assess and protect them if needed where removal of soils on the water side of the bulkheads is planned to dredging.Waterfront BulkheadsExisting bulkhead structures can be classified into two types: Cantilevered, and anchored. Cantilevered walls are completely supported by the soil on the water side, while anchored bulkheads are supported both by the soil on the water side and anchorage on the land side (Figure 1). Walls may be constructed of timber, steel, or concrete. Timber walls may be lagging with soldier piles, cribbing with soldier piles, or timber sheeted such as Wakefield walls (Figure 2). Steel bulkheads are most commonly constructed using sheet piling comprised of interlocking A or Z shapes, though some historic walls were constructed with flat sheets. Precast concrete sheet piling has also been used in construction of bulkhead walls. Anchorage may be provided by steel bars or tendons attached to deadmen, sheet piling, driven piles, or earth anchors."

Jan 1, 2017