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By Jim Bruce

The Transformation AGO project, constructed between 2005 and 2008, featured a foundation trade contract that included design of pile caps and grade beams and construction of 138 permanent micropiles. The new foundation works were constructed within seven different settings ? each featuring a host of attributes challenging to constructability ? inside and outside the existing Art Gallery of Ontario, all while the gallery remained open for business. Transformation AGO resulted in several firsts for micropiles in the Toronto construction market: this was the first micropile trade contract with a multimillion dollar contract value; it featured the first static compressive load test performed beyond 7000 kN on a single micropile; the first static compressive load test beyond 8000 kN on an experimental pile cap supported by two test micropiles; and it was the first publicly funded project to go to tender with micropiles listed as the preferred foundation option. This paper outlines the successful application of micropiles at the landmark Transformation AGO project.

Jan 1, 2011

By Eiji Kojima

In this research, dynamic and static load tests were performed on permanent foundation piles which had a pile length of 30 m, 800 mm in outer diameter and 15 mm in wall thickness. In this site the dynamic horizontal load test on a smaller test pile, 12 m in length, 500 mm in outer diameter and 12 mm in wall thickness, was also carried out. The static horizontal load versus horizontal displacement derived from the dynamic load test conformed well to that measured in the conventional static horizontal load test of the pile with 800 mm diameter. Then an attempt was made to predict the horizontal load displacement of the pile with 800 mm diameter based on the results of the dynamic horizontal load test of the pile with smaller diameter of 500 mm.

Jan 1, 2006

By Drew Floyd

Five full-scale pile load tests were performed on pairs of PZ-22 sheet piles installed with a vibratory pile driving hammer. The sheet piling was installed in several locations in soil generally consisting of miscellaneous granular fills overlying soft organic silts, inorganic silt interbedded with sands and gravels, very dense glacial till and shale bedrock. The test program also included the use of tip tell tales to determine what capacity could be attributed to tip resistance and skin friction. During the design phase of the project, it was assumed that the capacity of the sheet piles driven with the vibratory hammer could be correlated with the rate of penetration. The correlation between vertical capacity and rate of penetration would be used as a basis for determination of a driving criteria from driving the production sheet piling. The sheet piling load tests demonstrated that it was not possible to correlate the capacity of sheet piling driven with a vibratory hammer and the rate of penetration. It was also demonstrated that the capacity of the sheet piles was directly related to the density of the soil at or just below the tip. The results also tend to agree with empirical equations provided by Meyerhof (1976).

Jan 1, 1989

By Z. Y. Ding

This paper emphasize two points in piled wharf design which are important than structure calculation. First, during design of piled wharf on soft stratum, the bank slope stability is the first important item. Second, the live load, the backfill and the original ground's settlement will influence the wharf structure causes cracks. Two practical examples were illustrated.

Jan 1, 1991

By O&apos, M. W. Neill

Mini-piles have been found to be a practical, technically correct remedial underpinning method. They can be constructed in limited access areas with very little disruption. Experience indicated that mini-piles installed using a down-the-hole soil displacement hammer would be particularly effective in the "bottomless" Beaumont Clay formations in the Houston, Texas, U.S.A. area. The University of Houston Foundation Testing Facility was ideally suited to perform tests on mini-piles. The availability of extensive geotechnical data and previous pile test results was invaluable in evaluating the mini-pile test data. As expected, the mini-pile test results were consistant with test results from large sized driven piles in the same soil formation.

Jan 1, 1989

By Jan Pru?ka

This paper describes the sheet pile design for the Line C extension from Ládví station to the North of Prague. The first part of the paper describes the geological conditions and structural configuration of the project. Typical cross sections, the description of the construction stages, and monitoring are discussed. The second part of the paper focuses on the sheeting design method. It describes the method of dependent pressures, that is, how the pressures acting upon a structure depend on the deformation. The design process and verification methodology are described in detail with comparison of the results with in-situ monitoring.

Jan 1, 2011

By Larry Rayburn

In the spring of 1999, construction commenced on the new Steelers Football Stadium in downtown Pittsburgh, Pennsylvania. Richard Goettle, Inc. (RGI) was the successful bidder to install the specified augercast piles for the foundation package. Description - Pittsburgh Steelers Stadium The new stadium will house the Pittsburgh Steelers Professional Football Team. It is widely believed that if a team is provided with a modern playing facility, that a winning season will ensue (Not always the case). The new stadium location is on the north side of Pittsburgh on the Ohio River, and just downstream of the confluence of the Monongahela and Allegheny Rivers. The site is west of existing Three Rivers Stadium. The Three Rivers Stadium was built during the late sixties and housed both the Pirates Baseball and Steelers Football Teams. The Public Auditorium Authority elected to replace this outdated stadium with two new stadiums, one for each professional team. The landmark stadium was imploded in February of 2001.

Jan 1, 2001

By David C. Kraft

A major manufacturer and user of machine tools had the need to install a screw press machine at its plant site with the following design load requirements: (1) Vertical Compression Live Load = 2000 kip (8896 kN) and Dead Load = 1000 kip (4448 kN), (2) Rotational Moment = 6600 ft-kip (8950 kN'm). The screw press machine was to be located within an existing manufacturing building. The bottom of the footing base was located 15 ft (4.6 m) below existing floor slab. A geotechnical investigation of the site indicated a 17 ft (5.2 m) thick initial stratum of stiff to very stiff clay underlain by a 14 ft (4.3 m) thick stratum of loose to medium dense sand. Beneath the sand stratum was soft rock described as weathered shale. Obvious concern was raised on the possible effects of the dynamic motion of the screw press and potential resulting settlement within the loose sand stratum. This combination of large loads and dynamic motion resulted in the selection of a helical pile and tieback system to support the concrete foundation. The helical pile foundation system consisted of a group of vertical helical piles installed into the shale rock and a group of inclined helical tiebacks set into the remaining portion of the clay stratum. Four load tests were conducted on the vertical helical piles in order to establish compression load capacity. The results of these load tests as reported herein, led to the addition of a limited number of tubular steel push piles in order to meet the project required Factor of Safety on the design loads. All of the helical piles, push piles and inclined helical tiebacks were successfully installed and the screw press is now installed and operational.

Jan 1, 2003

By Daniel J. Rider

In 1980 the Niagara Frontier Transportation Authority contracted for three miles of cut and cover box structure and station construction in Main Street, Buffalo, New York. Project depths ranged from 30 feet to 60 feet below street grade. Soils, Figure No. 1, consisted of loose to very compact sands and gravels. Ground water level was generally 20 feet below grade. Specifications required a soldier pile and timber lagging support system with external dewatering. Soldier piles were to be installed in prebored holes with bentonite slurry and lean concrete backfill. Conventional pile driving was not allowed due to concerns over excessive noise and vibrations and its effect on nearby historic structures and the surrounding population

Jan 1, 1987

By Dan Brown

A method is outlined for computing the contribution of a micropile group to global stability of a sliding mass. The forces in the micropile are computed in a way which accounts for the effect of soil mass movement on the mobilization of axial and shear forces and which maintains compatibility between shear and axial force as a function of displacement. The method provides a rigorous model to incorporate the pile forces into the stability calculations, including the effect of pile forces on the resultant shear and normal forces at the sliding surface. This paper demonstrates the proposed solution using a simple example slope.

Jan 1, 2007

By Sachihiko Tokunaga, Hirofumi Taguchi, Kenji Maruyama, Hidenori Takahashi, Yoshiyuki Morikawa

"Abstract The present study proposed a new liquefaction countermeasure to improve sandy ground and conducted a trial execution. The new method is a floating-type and lattice-shaped cement treatment method, where cement-treated soil is not fixed to a non-liquefiable stratum. A fixed structure such as treated soil should be formed at the side of the floating-type treated soil to reduce its lateral displacement. In the study, one-dimensional dynamic response analyses were first conducted to confirm the mechanism of the new method. Then, a series of centrifuge model tests were performed to demonstrate the effect under a stress condition at the prototype scale. The analyses and model tests confirmed the effect of the liquefaction countermeasure. Finally, trial executions were carried out to confirm high-quality vertical execution.INTRODUCTIONLiquefaction induced by an earthquake generates sand boiling and ground settlement. Other problems have also been reported, including a decrease in bearing capacity and an increase in the horizontal earth pressure against retaining walls. To prevent these problems caused by liquefaction of the ground, various countermeasures have been proposed, such as cement deep mixing and high-pressure jet mixing methods. These methods have the big advantage of being applicable to ground that contains soil with a fine-grain fraction. Furthermore, the unnecessary displacement caused by the construction can be reduced. In Japan, a lattice-shaped cement-treatment method has frequently been used at many construction sites to prevent liquefaction, where cement-treated piles are intersected to form a lattice, as shown in Fig. 1. The lattice-shaped walls can reduce the shear stress generated by an earthquake, restricting the liquefaction at that location. However, the construction cost of the cement treatment is relatively high compared to other methods such as the sand compaction pile (SCP) method, and needs to be reduced. In particular, the cost of the high-pressure jet mixing method, which can be applied to the liquefiable ground under existing structures, is significantly high. Therefore, decreasing the total volume of the cement treatment is necessary to reduce the construction cost."

Jan 1, 2014

By J. Nakayama

Down-the-hole hammer is commonly recognized as the most powerful drilling equipment for weathered to fresh rock formation including boulders. However, its drilling diameter is restricted by reasons of difficulty to actualize large diameter drillhead and to ensure discharging means of cuttings. Cuttings are usually removed by flushing i.e. uprising return air after compressed air actuates hammer, but in case of large diameter drilling, as the clearance between drill rod and surrounding wall of hole become fairly large, necessary up-hole air velocity to transport cuttings can not be maintained. In case of marine or underwater drilling or high groundwater table, orthodox down-the-hole hammer is obstructed its operation by water. This single head hammer drill combined large diameter drillhead with reverse circulation of drilling fluid enables large diameter drilling extending to 1.5 m, i.e. actualized large diameter mechanical drillhead incorporated with ensured cuttings removal means enabled this range of drilling. This paper introduces its features and actual applications to large diameter bored pile drilling for varied sorts of rocks in maritime construction projects.

Jan 1, 1996

By Robert W. Schaut

The use of micropiles is increasing for new construction and to retrofit distressed foundations in expansive soils. Typical micropiles in expansive soils have a lower section where the micropile grout is embedded in direct contact with the soil, and an upper section that is cased with rigid PVC pipe or other material to reduce the friction between the micropile and the surrounding expansive soil. In the upper cased section, the micropile grout is in direct contact with the inside of the casing. During construction, grout can flow upward into the annular space between the soil and the outside of the casing as the grout is tremied into the micropile. Thus, various interfaces may exist in a typical micropile, including soil-to-grout, grout-to-PVC, and soil-to-PVC. As the surrounding soil heaves, shear stresses are mobilized along the interfaces. The frictional characteristics of the interfaces are design variables that must be evaluated. For this study, an experimental program was conducted to evaluate the shear strength of the three interfaces listed above. Conventional direct shear testing was performed at a commercial testing laboratory. In addition, specialized testing was performed at Colorado State University (CSU). For the CSU testing, an interface testing protocol was designed using a modified triaxial cell to allow evaluation of the interface characteristics between rigid PVC and cylindrical specimens of grout or clay soil. It is shown that the shear strength of the soil-to-PVC and grout-to-PVC interfaces are similar, both of which are significantly lower than the shear strength of the soil-to-grout interface. This indicates that the use of a PVC casing in the upper portion of a micropile has a positive effect in reducing friction and the shear stresses resulting from expansive soil.

Jan 1, 2011

By Dario Libano

"The Line 5 Extension, in Sao Paulo, Brazil, is currently the most important investment in public transportation by Sao Paulo’s state government. It will connect the south part of the city to the city center, crossing through four other major Metro lines and stations; all currently in operation. The total extension of the line is 11 km (6.8 mi), and includes a new parking yard for the trains and 11 new stations. The Brooklin Station, one of the new stations due to be open and operating in 2016, has a unique geometry of five secant shafts.The original design included constructing five secant shafts stabilized by two plastic slurry walls using conventional grab technology. One slurry wall, along the Santo Amaro Avenue, was to contain the contamination plumes, and another was for temporary support to enable the excavation of the shafts. The final retaining wall design was changed to a concrete structural diaphragm wall that reduced the construction time of the shafts by half, allowing the contractor to meet the construction schedule. This solution also avoided dewatering effects in a geological region characterized by Quaternary sediments and environmental contamination plumes. It was the first time that a hydromill was used in such a situation in Brazil. The hydromill, by overcutting the panels, increased the quality of the joints, and decreased the probability of having seepage into the shafts. The hydromill also created a seepage barrier and avoided movement of the contaminated plumes.The GeologyLocal geology is composed of a superficial Quaternary soil, basically soft organic clays and sands and gravels. From the depth of 8 m (26 ft) until 18 m (59 ft), geology is composed by tertiary medium compact sand with thin silt-clay layers. From 18 m (59 ft) down, there are alternations between compact silt-sands layers with very hard clays layers. Each is approximately 5 to 10 m (16.4 ft to 33 ft) thick.The Initial Basic DesignThe original basic design of the Brooklin Station was to be constructed from five 40 m (131 ft) diameter intersecting circular shafts, all in a line along the axis of the Metro tunnel, in 555 days. In the excavation sequence, the odd shafts were first excavated, waterproofed and had part of their inside cast-in-place structure built before the even shafts were excavated. During the excavation of the even shafts, part of the odd shaft’s support was demolished and connected with the even support. A 0.8 m (2.6 ft) thick plastic slurry wall, acting together with the wire mesh reinforced shotcrete support, ensured the excavation stability around the five shafts."

Jan 1, 2014

By Harry G. Poulos

Ground movements can arise from a large number of sources and can have a significant effect on nearby piles and deep foundations. The loading of the piles by ground movements is a different mechanism to that arising from direct applied loading to the pile head, and consequently it is not generally possible to adequately analyze the effects of ground movements simply by applying some type of equivalent loading to the pile head. The main effects of ground movements are the development of additional movements, axial forces and bending moments in the piles, and thus the key design aspects are related to movements and to the structural integrity of the pile. However, the ultimate geotechnical load carrying capacity is generally not affected by the ground movements themselves. This paper will describe an approach to the analysis of ground movement effects on piles, considering axial and lateral movements separately. Some of the main features of pile response will be discussed for three specific problems involving ground movements: piles near and within embankments, piles near an excavation for a pile cap, and piles subjected to seismic ground motions.

Jan 1, 2006

By Stefan K. Schwank

The paper describes the two foundation techniques - mini piles and postgrouted bored piles. The mini pile system is presented with its design and installation parameters, especially the drilling technique. Two case histories demonstrate the application under extremely limited space and traffic conditions and the required modifications of the equipment. After the description of the postgrouted bored piles and its grouting technique, the paper gives a comparison of postgrouted piles and standard piles on a large basic test in Germany. The Brooklyn Queen's Expressway, N.Y., case history shows the application of this technique after redesign of the original proposal. 1. General Increasing requirements to improve existing foundations to carry additional loads and to increase the bearing capacity of bored piles leads to two new piling techniques: the mini-pile and the post grouted bored pile.

Jan 1, 1991

By Mark X. Haley

Foundation design and construction in Boston has changed dramatically during the past 10 years. Prior to 1985, the primary foundation element in Boston, where deep foundations are required, was driven end-bearing piles. Since 1985, drilled or excavated high capacity foundation elements have been utilized more frequently. This paper will provide a historic perspective of their use and a summary of design parameters for elements installed and founded in the bedrock. TOPOGRAPHY Boston was founded in 1630 by the Massachusetts Bay Company of John Winthrop and his hearty band of Puritans. The settlement was chosen for: ? its safe harbor, ? abundant source of fresh water, and ? peninsula setting offering protection of the ocean on almost all sides with high ground for fortification. These three factors were a direct result of past geologic processes that created the Boston Basin by erosion of the soft bedrock underlying this area as compared to the harder granite rock to the north, west and south. As the glacial ice sheets melted and moved northward, various soil types were deposited. During ice sheet re-advancement the hills and islands of Boston took on their precolonial shapes. The Trimont, consisting of Beacon, Mt. Vernon and Pemberton Hill, rose to 150 ft above sea level with the smaller Copps and Fort Hill to the north and south.

Jan 1, 1994

By Noreen Tarac, Pablo Forgoso, Philipp Schober

A multiple use storage facility building is being developed in the Philippines on a peninsula that was reclaimed in the 1990s without any soil treatment. The subsoil now consists of loose to medium dense silty sand underlain by a soft to medium stiff clay. A liquefaction assessment by analytical methods have shown that the loose to medium dense silty sand yields a high potential for liquefaction and lateral spreading during pthe design level seismic event. To mitigate the risk of liquefaction and lateral spreading, as well as assure the slope stability of the shoreline, a solution utilizing a combination of ground improvement techniques by means of a Mixed-In-Place (MIPTM) Lattice Grid Wall and Stone Columns was developed and successfully executed. For the detailed seismic design, a Finite Element 3D analysis was undertaken to simulate static and dynamic actions on the buttress wall. The liquefaction assessment and settlement calculation were carried out based on analytical design approaches. For the execution of the Lattice Grid Wall, the Mixed-In-Place (MIPTM) method developed by BAUER Spezialtiefbau GmbH was applied. The stone columns were installed using the Wet Top Feed method.

Sep 8, 2021

By Y. Duraisamy

This paper presents the compressibility of tropical peat reinforced with cylindrical cement column. When a cement column installed vertically in peat, its compressibility was reduced because of the hardened skeleton matrix formed by cement particles bonding with adjacent soil particles in the presence of pore water. The effects of diameter, number of columns and cement proportions in cement columns on the compressibility have been investigated in this study. The results indicated that compressibility index Cc and Ca decreased with the increase in diameter of the cement column. Specimens with 45 mm and 60 mm diameter of cement column were cured for 28 days, after which they were subjected to Rowe Cell Consolidation test. Based on the results obtained, it shows that cement columns can successfully reduce the compressibility of tropical peat.

Jan 1, 2007

By L. F. Albert

The paper describes solutions given to foundation problems during the reconstruction of a power plant set on fire, located adjacent to several still Working Units. After a detailed site and laboratory investigation, it was decided that it could be possible to include within the new foundations the preexisting cast in situ driven piles with enlarged base 50 cm in diameter and let them work with new 41 cm driven, cast in situ piles without enlarged base. Demolition of existing caps was carried out with expansive mortar in order to avoid any possible damage to piles, whose actual conditions were checked by several load tests. New piles were designed to support service load by shaft resistance, in order to limit total and differential settlement. When piles had to be driven adjacent to nearby structures, measurements of peak soil particles velocity were carried out while driving piles at decreasing distance from critical locations. By preboring most of the upper clay layer it was possible to reduce within safe limits for structures the induced vibrations.

Jan 1, 1989