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By Donald T. Robertson, Kurt Hecht, Michael K. Muchard

"This paper presents case histories of driven concrete pile damage detected with dynamic testing methods utilizing strain gages and accelerometers embedded in the pile at the prestressing yard during pile construction. Data from the embedded instrumentation is compared with data taken with external bolt on instrumentation and other test methods such as low strain testing on the same pile. In the most severe cases, the piles were extracted revealing and corroborating the embedded data collector results.INTRODUCTIONDynamic testing of driven pile foundations was originally developed in the late 1960’s and commercialized in the early 1970’s. While the methods of analyzing dynamic test data have improved with the advancement of computer technology, the test method and the sensors used to acquire the data have changed little. In 1998, under a research grant provided by the Florida Department of Transportation, (McVay et al, 2002) an Embedded Data Collector system (EDC) was developed. The collector utilizes two sensor packs, each consisting of one strain gage and one accelerometer, embedded near the pile toe and pile top. Utilizing the toe sensor pack, the system provides reliable real time pile end bearing capacity measurements. This end bearing capacity is combined with a Case Method Solution augmented with an automatic damping calculation to provide the overall pile capacity, pile skin friction capacity and pile end bearing capacity. Also, since the gages are embedded, they have the ability to track all changes from the casting yard (i.e. prestress), driving, and subsequent setup (freeze, relaxation, etc) at both the top and bottom of the pile."

Jan 1, 2017

By Richard Berry

The spacing of grout injections is typically about 2 to 2 V½ meters if the purpose of the grouting is densification of the in-situ soils. Hole spacing will vary with the in-situ soil properties and the grout injection rate; faster rates requiring closer hole spacing.

Feb 10, 2003

By Danny Déry-Chamberland, Peter Bowman, Michael Byle

"The Barrage des Quinze dam is a concrete sluice dam consisting of 19 spillway sections, each of which is approximately 7.6 metres wide and 14.5 metres deep. Rehabilitation efforts being performed on the dam including demolition and improvement of the roadway and spillway sections and grouting to mitigate underseepage. Initially, conventional cement grouting was attempted and was successful in 14 of the spillway sections, but unsuccessful in 5 of the sections due to the high water flows which washed the grout away. The removal of the roadway and portions of the piers during construction temporarily reduced the stability of the structure limiting grouting pressures that could be applied. This and the substantial high water flows (leakage) beneath the dam between the concrete/rock contact and within fractures in the upper rock formation created a challenging situation to create a cutoff.A grouting solution was developed that involved implementing several different grouting methods and materials including balanced high mobility grouts (HMG); low mobility grouts (LMG); polyurethane grouts; and sodium silicates. Because of the critical scheduling for the work, multiple approaches were planned and made available on site so that the work could proceed with the best technology with little, if any, time loss. The end goal of the grouting program was to create a seepage cutoff beneath the 5 sections of the dam in a stepwise process. The initial step was to fill the large openings and create a grout barrier to reduce the high water flow. The second step was to seal the contact between the base of the dam and the bedrock; and the third step was to complete closure by grouting a deep grout curtain into the underlying rock. Other features of the work included an extensive grout mix testing program, water pressure testing, borehole camera survey, and monitoring of the grout injections."

Jan 1, 2016

By Marcelo Chuaqui

We certainly have the data to back calculate it. I must admit that I haven't, at the moment my priority is not on what is the stiffness of the jet grout but is making sure that the jet grout is really there. It's a bit like what Stuart Littlejohn was talking about this morning in terms of grouting on the dams a small window causes a big problem so it's having the jet grouting there at all, at the moment must have been my focus rather than just what is the stiffness once you've got it there.

Feb 10, 2003

By Dr. Anup Kumar Mandal, Partha Roy, Shuvranshu Kumar Rout, Dipak Mandal, Biswajit Das

Installation of a new scalping station with bunker, apron feeder, scalping screen, ramp -retaining wall and approach bridge was planned in an existing integrated complex of phosphate fertilizer at a remote place in West Africa. Rock phosphate ROM, transported from mines by a combination of 100 Ton and 150 Ton dumper, would be fed to a steel bunker having capacity of 180 m3. Different options were studied for retaining wall at the junction of ramp and approach bridge. Initially options with conventional RCC Retaining Wall, Gravity Retaining Wall with Precast Concrete Blocks and Reinforced Earth walls were studied. Option with Reinforced Earth was selected as this option was much more cost effective compared to other options. But real engineering challenges cropped up when competent execution contractors were not available nearby the site. To minimize the cost, an innovative option with Stepped Retaining wall was then studied. Geotechnical parameters of native soils, selected for the construction of the approach ramp were determined and it was found that with available poor geotechnical parameters of the native soils, design of stepped retaining wall would not be feasible with respect to available bearing capacity, subjected dead load, live load, operational load and earth pressure. A conscious effort was then made to make the design feasible by improving the geotechnical parameters of the retained earth of ramp near the retaining wall. In view of that, mix design with locally available materials like Silexite, Sand, Laterite, Gravel and Silt at different proportions was made and samples were tested in the laboratory to determine relevant geotechnical parameters. Based on the test results, a suitable mix was selected that had high shear strength, enhanced bearing capacity and improved coefficient of earth pressures. Design of stepped retaining wall was then made with the selected construction materials and construction completed. The plant was successfully commissioned in December. 2021.

Sep 1, 2022

By Steve Davidow, Nick Salisbury

"The Sunrise Powerlink project received numerous industry awards for excellence. The DFI C. William Bermingham Innovation Award recognized the innovative use of prefabricated steel micropile caps to increase safety, accelerate project schedule and minimize the project carbon footprint. DFI’s Outstanding Project Award (OPA) and World Cup of Micropiles Challenge Award honored the project as a whole and its positive outcome and industry example. Sunrise Powerlink involved construction of San Diego Gas and Electric’s (SDG&E’s) new 117 mile (188 km) 500/230 kilovolt transmission line from Imperial County to San Diego County, Calif. The alignment traversed a wide variety of geotechnical conditions, including desert, mountain and marine environments, and many of the 421 lattice tower structures used to carry the transmission lines were located in remote, rugged or environmentally-sensitive terrain.Micropiles were introduced as a solution to foundation construction in these challenging areas, which ultimately involved the design and application of Crux Subsurface Inc.’s patented steel micropile cap at 234 tower locations. This was the inaugural application of the technology, and a significant component to ensuring a successful project outcome. Foundation ChallengesThe alignment crossed a number of protected environments, including National Forest land, critical habitat for bald eagles and Peninsular big horn sheep, and numerous private properties. As a result of the remote, rugged terrain, it was initially determined that 75 lattice tower locations would not permit road construction access and would require helicopter-only construction techniques. A strict in-service date combined with long permitting lead times eventually increased this number to 234 sites. Preconstruction access constraints prohibited site-specific geotechnical sampling, so initial foundation designs were completed using only available seismic geophysical surveying and preliminary mapping data. The combination of these challenges required a foundation alternative that could accommodate variable subsurface conditions, required a minimal environmental footprint for installation, and featured lightweight materials and equipment that could be transported by helicopter."

Jan 1, 2014

By Mark Koelling

This paper presents a case history of a ground improvement program conducted in a soft soil environment and seismically active region in the northwest corner of Washington State near the Canadian border. The program was performed over several years, and provided adequate soil bearing conditions for the construction of several structures. Completed development includes separate construction of four adjacent structures, each with unique total and differential settlement requirements and built at approximate two year intervals. Site soils consist of 45 feet of loose saturated sand and silt overlying 70 feet of very soft to stiff (N60 = 0 to 7) normally consolidated clay. Adding to the complexity of the site is the owner?s requirement that all existing structures remain open and in service during construction of each subsequent structure. The paper presents the site geotechnical information and the foundation design issues. Details of a combination of ground improvement methods is presented, including stone columns, wick drains, a preload surcharge, and staged construction to provide soil support for shallow foundation construction of all structures at this site. The soil test results and settlement observations are presented along with QA/QC measures. Lastly, a brief method sustainability comment will be made.

Jan 1, 2010

By Sherif Elfass, Gary Norris

Bi-directional load testing of drilled shafts has been widely adopted as a means to evaluate their load carrying capacity. However, in order to reach failure, most of these tests are carried out on sacrificial shafts using expensive sacrificial elements such as hydraulic jacks. A proposed low-cost bi-directional testing technique is discussed. It mechanically loads the end bearing soil below a drilled shaft, against its side shear resistance. The technique was originally established as an alternative to post-grouting to reliably account for the forfeited end bearing resistance. However, since it loads the shaft in a manner similar to conventional bi-directional tests, it can be used to not only load test sacrificial shafts, but production shafts as well. Furthermore, unlike conventional bi-directional load tests, the load is applied through surface jacks. These jacks, along with other load test components, are movable and can be reused to load test all the shafts of the project thus presenting an economic benefit. The concept of this technique has received favorable feedback from a few consulted departments of transportation, and while promising, has not been field tested to date. A U.S. patent was issued for the tip loading module and the loading technique described.

Sep 8, 2021

By Lisheng Shao

Soil mixing and jet grouting have been widely used to support heavy structures such as tanks, cement silos, and storage buildings. Although the installation methods vary between soil mixing and jet grouting, the end product of soil-cement columns behaves similarly in supporting structure loads. In many cases, soil-cement mass treatment offers the owner savings over driven/drilled piles. This paper discusses the design methodology, production work, and quality control, with supporting figures, of a recent large complex tank farm project. The project consisted of constructing six above-ground steel storage tanks and an approximately 700-foot-long fill slope. The tank farm site is located in an industrial area of southern California, with highly variable subsurface conditions consisting of compressible soils and buried construction debris. The compressible soils necessitated that the new tanks be supported on deep foundations. A test pile program performed previously at the site showed that conventional driven concrete piles were not feasible because of buried construction debris, therefore a soilcrete system was proposed. Site design included evaluating the total and differential settlement and column group bearing capacity under both static and seismic loads. Extensive field and laboratory testing confirmed the design soil-cement strength and modulus of both the soil mixed and jet grouted soil-cement columns. The project operation and quality control programs are also included in this paper.

Jan 1, 2010

By Mohamed A. Mansour, Ahmed M. Soliman, M. H. El-Naggar

"Grouted helical piles allow significant increase in pile capacity with low additional cost over that of conventional helical piles. They can be particularly advantageous in sites where installation disturbance can reduce or even eliminate the pile shaft resistance. For helical piles with slender shafts, a grout column offers increased buckling resistance under compression loading, and may reduce the potential settlement required to mobilize the bearing component of their plates. This paper investigates the performance of grouted helical piles installed in loose sand. Grouted helical piles were constructed and tested in a controlled laboratory environment. Helical piles with hollow pipe shaft and single helix were grouted during installation. The grout was injected into the soil under high pressure through two nozzles placed above the piles helices. The load test results showed significant improvement in the performance and load carrying capacity of the helical pile due to the formation of a cylindrical grout column along the entire shaft leading to a higher shaft resistance contribution to the total pile capacity. The results suggest that grouted helical piles with slender hollow shaft could be used to support large structural loads. INTRODUCTIONHelical piles are widely used as a deep foundation system for different engineering applications. They represent an attractive foundation option because of their cost effectiveness, ease of installation even in limited access areas, low levels of noise and vibrations, and their ability to be installed through ground water without casing. In addition, they allow immediate loading upon installation. Helical piles are installed into the ground by applying a mechanical torque to the pile head. The installation torque monitoring provides a kind of quality control during the construction of helical piles. It could be used in predicting the ultimate pile capacity using several capacity-torque correlations (Livneh and Elnaggar 2008; and Hoyt and Clemence 1989).However, helical piles installation can cause soil disturbance within the annular zone affected by the pile helices. This disturbance can introduce fissures within the pile cylindrical failure surface (Vesic 1971; Mooney el al. 1985; and Zhang 1999). Thus, the shear strength of the soil decreases along the affected zone. Bagheri and El Naggar (2013) evaluated the installation effects of helical piles in sand. They reported that as the helical blade proceeds into the ground, sand within the cylindrical path circumscribed by the helices experiences torsional and vertical shearing accompanied by sand displacement and stress changes. This process is more pronounced in the case of multi-helices and large diameter anchors. Bagheri and El Naggar (2016) evaluated the installation effects of helical piles in structured clay. They indicated that the behavior of the helical pile and its capacity are significantly affected by the degree of soil de-structuring induced by the penetration of the pile shaft and helices. In addition to the installation disturbance, helical piles have other drawbacks including; high potential settlement required to fully mobilize the bearing component of their plates, low buckling resistance of their slender shafts, and the incomplete rigidity of the coupling joints along the pile shaft that allow some lateral movement under compression loading (Vickars and Clemence 2000)."

Jan 1, 2016

By Boo Hyun Nam, Berk Turkel, Luis G. Arboleda-Monsalve, Jorge E. Orozco-Herrera

Construction of buildings, roads, and traffic activities generate vibrations to urban infrastructure. The vibrations produced by construction activities have an impact on the soil through which they are transmitted. These effects become much more significant in granular soils. The soil conditions in Florida consist mainly of sandy soil deposits and this makes driven piles a commonly used method. In the design of deep foundation installations, it is significant to consider the potential construction issues related to the driving process. This process generates vibrations in the surrounding soils and thus, its effects on nearby soils and structures must be considered. This paper presents a web-based survey conducted among geotechnical engineers in Florida to better understand the common practice and experience regarding the effects of pile driving on surrounding soils and structures. The perception of different practitioners in the state of Florida on ground deformations and damages to adjacent structures induced by deep foundation installations are investigated. The engineers who have experienced ground vibrations and deformations were asked to define the susceptible soil conditions and main triggering factors of large ground deformations induced by pile driving. Sandy soils with loose to medium relative densities were found to be the most susceptible soil condition to generate ground deformations. Conclusions are drawn regarding the importance of considering ground vibration monitoring during the design phase of deep foundations.

Oct 1, 2022

By Ameir Altaee

Unconventional means and methods were utilized to install over 650 contractor-designed micro-piles for the replacement of the Bronx approach to the Bronx-Whitestone Bridge in New York City. The method utilized reverse circulation (RC) drill rods and down-hole-hammers (DHH) along with grouting through the DHH bit. The overall construction sequence of drill-down, grout-up, place reinforcing is similar to auger-grout piling. The extremely tough drilling conditions required the use of a percussive DHH. The piling subcontractor refers to this pile as a hammer-grout pile. Project background, constraints and subsurface conditions are given. The proposed means and methods as well as the collaboration between stakeholders are detailed. Results of load testing and production installation are summarized.

Jan 1, 2010

By David Pierce

The Port of Seattle, one of the largest on the west coast of North America, made a strong statement regarding their support for reusing existing structures when a decision was made to rehabilitate Pier 69, on Seattle's downtown waterfront, for their new headquarters. Because of its age and location, the pier provided an unusual challenge to the Port and its consultants. The Port hired Peratrovich, Nottingham, and Drage Inc. to design the seismic strengthening of the pier itself. To remedy the lack of seismic resistance in the 70-year-old pier, PN&D designed a new steel-pipe-pile supported concrete apron next to it. The structure relied on a development by PN&D, the "spin-fin pile", to achieve the tension capacities required of the batter piles. The construction of this apron was completed in October of 1991. Another team of consultants performed the superstructure renovation design, which is now under construction.

Jan 1, 1992

By Jean Wehbe, Daniel C. Brahana

"This paper presents a case history of drilled pier construction for a new stadium in Atlanta, Georgia. The stadium structure is supported on several different foundation types, with the heaviest ""mega columns"" typically bearing on drilled pier supported mats. The project includes 141 drilled piers with design diameters of 5.5, 6 and 6.5 feet. The piers bear on bedrock at depths of 20 to 110 feet below the ground surface. Many of the piers included rock sockets with design lengths of 5 to 18 feet. A pre-production drilled pier load test program was completed including one Statnamic load test, two Osterberg Cell tests and two lateral load tests. Non-destructive testing (crosshole sonic logging and sonic integrity testing) were also performed during construction. Production pier installation with over 3800 linear feet of earth excavation and over 1350 linear feet of rock excavation was completed in a little over four months. The piers were installed using both the cased hole method and the slurry method. All cased holed required downhole inspection and slurry holes were initially inspected with a mini-SID device and subsequently by sounding. Advanced drilling equipment and tooling were used to meet the production requirements for the project. This paper reviews the highly variable soil and rock conditions encountered at the site, briefly presents the results of the load tests, and discusses pier installation procedures and the equipment used for installation. The paper also presents conclusions related to the installation and lessons learned.INTRODUCTIONWith the opening of AT&T Stadium in Dallas, a new era of stadium construction began in the U.S. The new age stadiums are larger and have more amenities than their predecessors. The new Atlanta Falcons stadium is no exception. Many of the new features, including Atlanta’s innovative retractable roof, result in extraordinary structural loads. The roof structure is supported by a series of mega columns that bear on eight large caps, six of which are drilled pier supported. Each of the pier caps contains between 8 and 16 drilled piers that bear in the underlying bedrock. The design pier diameters are 6 and 6.5 feet. Augercast piles were used to support two of the mega column caps. Drilled piers, augercast piles, aggregate piers and spread footings are used to support the more lightly loaded portions of the structure."

Jan 1, 2017

By Donald T. Robertson

This paper presents case histories of driven concrete pile damage detected with dynamic testing methods utilizing strain gages and accelerometers embedded in the pile at the prestressing yard during pile construction. Data from the embedded instrumentation is compared with data taken with external bolt on instrumentation and other test methods such as low strain testing on the same pile. In the most severe cases, the piles were extracted revealing and corroborating the embedded data collector results.

By Abid Adekunte

"Whilst safety is considered to be of high priority in every aspect of engineering projects, it is equally important for designers and contractors to be continually aware of their obligations to the immediate environment and the society as a whole. These include responsibilities to minimise the amount of nonrenewable natural resources and energy used on projects, to reduce carbon foot prints on projects, to minimise the quantity of wastes produced on projects, to minimise the level of pollution on construction sites and to reuse materials and waste products whenever and wherever possible.In other words, professional engineering practice needs to be accompanied by an underlying fundamental objective to improve, restore and sustain the environment. However, achieving this objective requires continuous collaborative interaction and effective communication between the different specialists involved on every project from the early stages. In addition, developing a well-thought-out economical solution is key to achieving the sustainability aspect of the above objective.This paper focuses on the design, construction and management of a recently completed large multi-level basement scheme in Central London, with greater emphasis on collaborative approaches taken by the design engineers, commercial managers, construction managers and site operatives to deliver the most reasonably economical and sustainable solutions to the client. Solutions were based on combinations of general and specialist engineering knowledge, with due considerations for health & safety, sustainability, cost, practicality, time and community requirements.INTRODUCTIONUnderground structures have become vital components of urban life worldwide e.g. tunnels serve many water, wastewater, highway and railway schemes, basements have been incorporated into many urban commercial, institutional and residential developments, while many public underground car parks have been built to deal with the incessant problem of insufficient surface parking spaces in busy urban centres.The safe design, construction and maintenance of underground structures have been well-mastered by the deep foundation industry over the years. However, just like many other areas of engineering, aside the need to satisfy safety requirements, underground construction practice is now faced with a new set of requirements; the demand for more sustainable and cost-effective solutions, with reduced environmental and societal impacts. Designers and managers of underground construction schemes are now compelled to minimise the use of natural resources and energy, to minimise the amount of waste produced, to minimise the level of environmental pollution, noise and disruption to traffic and normal societal life at ground level around underground construction sites. In addition, the recycling of site wastes and reuse of materials have now become important aspects of underground space development. Considerable effort is being put into promoting sustainable development across the industry."

Jan 1, 2017

By Jeff Starchuck, Harald Kullmann

"In 2005, an inspection showed that the Deception Bay Wharf in the Canadian Arctic was at the end of its service life. Although Deception Bay is closed with landfast ice up to 5 ft thick, shipping operations continue year-round, with additional voyages in the summer open-water season to supplement mine supplies. The rehabilitation scheme that allowed minimal interruptions to shipping involved concrete caissons cast on barges and an ingenious placing system.WorleyParsons Westmar of Vancouver, B.C., performed the inspection under contract to the owner, Xstrata Nickel, Montreal, Quebec. The wharf, on the coast of the Nunavik region of Quebec, was originally constructed in 1971 for an asbestos mine, and is now used to support Xstrata’s Raglan nickel mine, importing fuel for p o w e r g e n e r a t i o n a n d general mine supplies, and exporting nickel concentrate to smelters in the south. Emergency repairs were essential to allow operations to continue at the site, while the parties considered permanent rehabilitation options and secured funding. The repairs were done in the openwater seasons, and included reinforcing the failed interlocks above water level with steel patch plates and injection grouting of the cell fill below the port crane in 2005. In 2006, workers installed a circumferential belting system below water level.Westmar held critical planning sessions with the mine operation personnel to find ways to stretch the limits of the mine supplies and nickel storage facilities. In the end, the parties agreed to shut down construction activities four times during the ice-free season to allow access to the dock site.Westmar developed a plan that allowed mine operations to continue during construction, and Xstrata approved the plan and budget in September 2006, for execution in 2007. Rapid construction was essential. To accommodate the short construction season and maintain minimum levels of service for the mine, the work was radically different from conventional Arctic deep-sea port construction. Like the original Deception Bay Wharf, construction practice was to use steel sheet pile circular cells with the consequential heavy support services for the labour force. Construction duration was typically two seasons. The plan for Deception Bay was executable in one season based on a concrete caisson structure. Only a modest amount of schedule float was needed."

Jan 1, 2009

With respect to liability damages, claims and costs thereof relating to or ansmg out of contamination, special or non-special wastes, hazardous wastes or pollution in connection with the performance of this subcontract: It is understood that the subcontractor's work and responsibility wholly exclude any requirement to handle such contaminants or to otherwise be responsible for such contaminants, and Subcontractor shall not be nor be considered to be a generator of such contaminants. Contractor shall indemnify, defend and save harmless Subcontractor and its sureties, from and against all liability, damages, claims and costs relating to or arising out of contamination, special or non-special wastes, hazardous wastes

By Lynn Crayne

We used Glyoxal as the hardener, at a final concentration of 10% by volume and therefore 20% by volume in the A-Component. They worked pretty well what we did was we shaved the joints on each of the pipes when we assembled them so they wouldn't rip the packers and then we greased the packers very well going in. We had to replace some but we have any getting stuck or didn't lose any pipes.

Feb 10, 2003

By Denis Huber

The technical assessment of the final works on the "Stéphany Palace" project at Menton in France's Alpes-Maritimes region shows the importance of daily project monitoring based on the observation method recommended by the European standard Eurocode 7 which applies to Foundations and Geotechnical Engineering. Excavation operations to a depth of 10 m near the France-Italy railway track and adjacent buildings required precise observation of land deformations, regular piezometric monitoring as well as special design arrangements. Temporary active tie-rods were thus placed in phases in order to control deformations in the retaining structures resulting from excavation operations. The Menton region, terminating the Alpine arc of mountains, naturally required the consideration of seismic forces in phase in the lower floors of the building, directly linked to the buried walls. These calculations were carried out in accordance with the PS69/92 rules, calling for an increase in dynamic thrust under the effect of gravity field rotation.

Jan 1, 2002