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By Philip Dubbeling

Conventional dynamic sheetpiling techniques are ill-suited to urban development because of the emission of excessive noise and ground vibrations. Drilled shafts and slurry walls alleviate some of these environmental concerns but add additional problems due to large bulky machines, reliance on dusty concrete plants and urban trucking grief. To solve these problems, pre-fabricated sheetpiles are hydraulically jacked-in by reaction principle using a compact and lightweight press-in machine, a so called the "Silent Piler". Through scientific analysis, definition and systemization of press-in machines and methods, new construction concepts such as the one-step approach, implant structures, functional design and life cycle design have been developed to comply with new basic construction principles.

Jan 1, 2006

By Gyimah Kasali

Rapid Load Testing was performed as part of an extensive drilled pier testing program for the University of California Berkeley Capital Improvement Program. The purpose of the program was to: (1) Verify the axial compressive design capacity values for the planned 24" piers, and to estimate the capacity of the existing 30" CIDH piers, and (2) To evaluate the seismic performance of the proposed drilled shafts. The Fundex PLT was used since the loading period of the PLT is very similar to the period of a seismic event, making it an ideal tool to model the pier response to seismic events. "Performance-based design" of structures subject to seismic loads has been of particular interest to UC Berkeley Seismic Review Committee and the Pacific Earthquake Engineering Research Center. The comparison of static tests to Rapid Load testing also provided valuable correlations. The program represents one of the most comprehensive drilled pier test programs on the West Coast. The testing program consisted of Rapid Load Testing using the Fundex PLT on 6 drilled piers. Rapid Load Tests were followed by conventional static compression and tension tests on selected piers, followed by another cycle of rapid load tests on the statically tested piers. The piers featured extensive instrumentation to allow detailed interpretation of the test result. Correlations were drawn to compare static load test result to that of the PLT in the particular soil profile, and the PLT also provided the data to analyze the ultimate seismic capacity of the piers. The load test results indicate that the ratio of interpreted failure load from the PLT data to the corresponding load from the static load test data is about 1.2 to 1.3 for the clayey soils underlying the test site. The results also indicate that the PLT offers an economical approach to defining the stiffness of drilled pier foundations subjected to seismic loads for use in performance-based design.

Jan 1, 2002

By Kul Bhushan

This paper presents the results of lateral load tests on 0.61-m to 1.27-m (24 to 50-inch) diameter drilled and cast-in-place piers in San Diego area residual/formational soils. The test piers were installed and tested in the following soils: Decomposed Granitic Rock (Ktd), Stadium Conglomerate (Tst), and Friars Formation (Tf). Lateral loads of up to 845 KN (190 kip) were applied to the piers in residual granitic soils, and loads up to 1780 KN (400 kip) were applied to the piers in Stadium Conglomerate and Friars Formation. The tests were conducted by jacking against adjacent piers and monitoring the lateral load and lateral deflection at the ground line. Test results indicate that ultimate lateral pile capacities of up to 1800 KN (400 kip) can be obtained for 0.61 m (24-inch) drilled piers with penetration of 3 to 6 m (10 to 20 ft) in the residual/formational soils tested. Lateral load analyses using p-y curves for very dense sand significantly overestimate the observed lateral deflections. For lateral load analyses using dense sand p-y curves, p-multipliers that increase the lateral soil stiffness (p-y curves) by 2 to 8 times are required to match the load-deflection behavior measured in the test piles. When applied to the dense sand p-y curves, the p-multipliers provide a more accurate prediction of load-deflection behavior in the residual/formational soils, and can result in shorter required pier penetration and significant savings in foundation cost.

Jan 1, 2002

By Yu Zhenquan

At the construction site of Bao Shan Iron &. Steel Mill in Shanghai, lots of RC driven piles with length of 50 to 60m were applied. The most unfavourable distribution of stress along the pile shaft was known by measuring the compressive and tensive stresses. With analysing the test results a phenomenon of impact fatigue of RC pile was discovered, the range of impact fatigue and its critical zone can be distinguished. Finally some countermeasures are presented to avoid the impact fatigue of RC long pile.

Jan 1, 1991

By W. Robert Thompson

Hurricane Katrina caused significant damage to transportation structures on the Gulf coast in August, 2005, including the destruction of the US 90 Bridge over Biloxi Bay, Mississippi. Part of the successful design/build proposal for the replacement bridge included a comprehensive test pile program of indicator piles and load test piles in the geotechnical investigation program. A total of 22 indicator piles were installed on the project using the pile driving analyzer to monitor the pile behavior. Five load tests were performed: two axial Statnamic, two lateral Statnamic, and one static axial. The results of the test pile program established driving criteria for production piles that included end-of-drive blow counts and pile tip elevations with an appropriate allowance for setup. The program also confirmed that the planned installation equipment and techniques of GC Constructors, a joint venture of Massman Construction Co., Kiewit Southern Co., and Traylor Bros., Inc., would install the piles to the design tip elevations before production piles began. An extensive program of restrike measurements at a range of times after initial driving of the indicator piles provided a systematic documentation of pile setup in the soil profiles on the site. These resistance values were used to develop a dimensionless setup factor ?S? as the ratio of the restrike resistance to the end of drive resistance. This factor varied from 1.5 for piles penetrating clays and tipped in sand to 3.0 for piles bearing completely in clay and helped establish an end-of drive blow count that included an allowance for setup. The CAPWAP analyses of restrike data with setup and the load test data were used to confirm the design unit side shear and end bearing values developed from the borings and static capacity calculations and to select the design pile lengths.

Jan 1, 2009

By Peter J. Nicholson

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

Jan 1, 1991

By Chris G. Leach

"Abstract A seven storey Northbridge area of Perth, Western Australia presented residential apartment complex located in the an opportunity for a novel application of Cutter Soil Mix technology (CSM). The development included a two-level basement for car parking which covered the full site area. However, the basement was also required to extend under an existing single story heritage building. Soil conditions comprised 2m of fill overlying medium dense to dense sands that in turn were overlying a very stiff clay stratum at approximately 14-16m depth. The ground water table was located at a depth of approximately 1m below the natural surface level.A site boundary consisting of a reinforced CSM retention system and was designed and installed to allow the excavation to proceed to basement level. Two rows of temporary soils anchors or inclined struts were required to achieve this. A CSM support system for the heritage building was also designed and constructed to provide temporary support during excavation and permanent construction works. The brief for the contract works emphasised that it was vital that settlements of the heritage building be kept within strict limits.CSM is a relatively new introduction to the Australian construction market, using a modified trench cutter to mix a binder slurry with in situ soils, generally to form cut-off walls, retaining walls and soil improvement works. This project is understood to be first application of the CSM for underpinning work in Australia.This paper discusses the site background details leading to the decision by the client to adopt CSM technology, and the design and construction aspects to meet the challenges offered by this project.Introduction190 Newcastle St is a 7-level residential apartment complex located in the Northbridge area of Perth, Western Australia. The development includes a 2 level basement for car parking, which covers the full site area. The basement also extends under a single story heritage building, which remained in-situ throughout the building works.A site boundary retention system was required to allow the excavation to basement level to proceed. In addition, a support system for the heritage building was required to provide temporary support during excavation and permanent construction works."

Jan 1, 2014

By Dan Brown

Two drilled shaft foundations were subjected to axial load tests in order to measure the influence of drilling fluid on performance. Other than the differing drilling fluids, the shafts were constructed with great care to ensure identical conditions. The results indicate superior performance in both side shear and base resistance of the shaft constructed using a polymer over that of the shaft constructed using bentonite drilling slurry.

Jan 1, 2002

By Lucien Weber

In the Shanghai area, the soil conditions are such that bearing piles have become an essential foundation part of the new highrise buildings. In order to reduce the settlements under the high working loads of about 2300 kN/pile, the Chinese building authorities require the pile tip to penetrate into the compact sand layer, situated at approx. 60-70 m depth. No H-piles have yet been tested under these conditions in Shanghai. This paper describes the driving of 8 H-bearing piles with 4 different shapes and with lengths varying from 45 to 75 m. Dynamic measurements are performed during driving and after a wait time of approx. 40 hours in order to assess the change in bearing capacity in function of time and in order to get an idea about the resistance distribution along the piles by using a stress wave analysis program (CAPWAP). One pile is equipped with channels between the flanges for executing verticality measurements with an inclinometer. However, this test has not yet been performed. One month after driving, two piles of 75 m length are statically loaded both in vertical and in horizontal directions.

Jan 1, 1987

By P. B. Kelleher

Most of the piers and other pile-supported marine structures in the New York City Harbor area were constructed prior to the widespread use of currently available pile protective systems. As a result, the support piling of many existing marine structures have experienced deterioration to an extent that their structural sufficiency is impaired long before the useful life of the structures they support is over. This situation presents special and unique problems of how to restore the structural integrity of these piles while at the same time allowing full use of the structures they support. Spearin, Preston & Burrows is a 100 year old New York City-based marine construction firm specializing in waterfront and foundation construction. In recent years it has undertaken and successfully completed several unusual projects in the New York City Harbor area involving the rehabilitation of existing, deteriorated piling underneath major, economically important marine structures. This work was accomplished using techniques that permitted full use of these structures. Several different pile rehabilitation systems were used, each having their own particular application to the deterioration problems of the piles supporting each structure.

Jan 1, 1989

By W. J. Grose

The Embankment Place office development over the platforms of Charing Cross Railway Station in London has presented many interesting and unusual problems to the engineers involved with the project. The main structure is supported on widely-spaced columns which penetrate the station platforms and underlying vaults, calling for high capacity foundations built in severely restricted spaces. Hand-dug underreamed piles were chosen. Whilst a conventional design approach was taken to size the piles, a detailed appraisal of ground movements was made to explore the effects of the new building loads on the existing foundations, not only beyond the site perimeter but also those amongst the new foundations. Before construction of the pile proper could take place, it was necessary to sink a caisson through the upper unstable and water-bearing soils. This being identified as a high-risk item, a full-scale trial was carried out prior to embarking on the main works. The twenty-one hand-dug piles were 2.5m diameter, over 30m deep and belled out to between 4.5m and 6.6m.

Jan 1, 1989

By Sheryl D. Gallagher

The project consisted of filling an abandoned underground limestone mine to facilitate construction of a new entrance ramp to I-470 in Lee?s Summit, Missouri. Due to collapse of mined areas near the project site, design included determination of the limits of remediation for the project and minimum construction requirements for mine infilling. The Judy Company, contractor selected for the mine infilling, experimented in the laboratory with several grout mixes to determine the appropriate mix for the project. Infilling was accomplished from the ground surface, and camera observation was used to monitor the barrier wall construction and infilling process. It was discovered that some of the mapped rooms were larger and some were smaller than indicated on the construction plan.

Jan 1, 2009

By James Green

It has often been said that the best contracts written are by people who are suspicious of each other. The Spanish philosopher, Ortega y Gasset, said: "Every contract is an Act of Distrust." The arena for dispute settlement outside of the courts is increasing day by day - contracts, especially construction and civil engineering contracts, are written containing arbitration clauses for settling disputes - the very drafting of standard forms of contract, do in some instances by their very construction, create an ambiguity as to intent and provide a breeding ground for dispute. I come from a land far across the sea - the most southern land before the South Pole. Being a young country, 150 years old, we are still progressing - being far removed from the trouble free zones of the world and nuclear free we enjoy a lifestyle second to none.

Jan 1, 1987

By Bill Starke

The acceptance of AugerCast piles in Canada has been limited. Many engineers are apprehensive about the quality of the piles produced by this method. However, advances in the sensing instruments and computer technology can now provide satisfactory levels of quality assurance. Post construction tests such as the sonic echo method can give an indication of pile shaft integrity. Computerized monitoring of the pile installation process is an immediate and more positive method of quality assurance. The computer continuously measures and records the parameters which indicate the quality of the pile. If these parameters do not indicate a satisfactory pile, it is replaced before the concrete hardens. Computerized monitoring of the installation process is another tool available to the engineer. The data from this system analyzed with soil borings, site inspections, and possibly sonic tests can provide the engineer with enough information for pile certification.

Jan 1, 1997

By David G. Winter

The Olive 8 excavation site in Seattle was surrounded on three sides by conditions requiring innovation, careful modeling, and extensive instrumentation to support use of a first-of-its-kind shoring system. The solution combined heavy soldier piles, long and steeply angled tieback anchors, and tightly spaced soil nails to support surcharge loads from a 33-story adjacent tower separated by a narrow alley housing critical utility lines. Land restrictions on two other sides of the site also required innovative applications of traditional methods. The Olive 8 project has won three state and local awards for innovation and has been reported on in Engineering News-Record and has been the subject of two feature articles in the Seattle Daily Journal of Commerce. This paper presents the conditions and site challenges, reviews the design analysis, discusses the shoring performance, and looks at other potential applications.

Jan 1, 2009

By Mike Fabius

The Lakehead Region Conservation Authority is responsible for slopes along the Kaministiquia River, one of the largest tributaries to Lake Superior in Canada. After arresting toe erosion for a mile of riverbank, the remainder of the slope required stabilization to stop further crest regression and to protect the houses, street and services at the top. Stabilization of the 100 ft. high slope was tendered as design-build with a target safety factor of 1.3 and a design life of 75 years. The successful bid was a system of 1.4 inch diameter soil nails up to 40 feet long, installed perpendicular to the slope on a 3 to 5 foot grid. The conventional shotcrete facing was replaced with a ?green? biotechnical facing and special transverse plate heads on the nails. The key to keeping costs low proved to be installation with light equipment working on the slope, and driving the nails without drilling or grouting. Rather than tension, the design was based on bending in the nails, similar to a laterally loaded flexible pile. The paper describes the design and installation of this innovative system. The design is discussed in terms of soil properties, nail resistance as it varies with depth, failure modes, corrosion protection, root design and nail head design. Construction challenges are discussed. The system is compared to an adjacent anchored soldier pile wall built along the same slope 20 years ago. Post construction monitoring results confirm predicted performance.

Jan 1, 2006

By Kazunori Matsushita, Frank Vespi, Emi Walder, Mitsuo Nozu

During the runway expansion project at the Fort Lauderdale-Hollywood International Airport in Florida (FLL project), therewere complicated geotechnical issues with a number of cavities in the limestone-loose sand mixed ground thatexisted in many areas below the existing ground. Collapsing the cavities and compacting the runway foundation to secure the take-off and landing of aircrafts was a necessary requirement for the project. The Mammoth Vibro-Tamper (MVT) which produces less vibration and noise level, was proposed and accepted as the alternative to the originally specified Deep Dynamic Compaction (DDC) for the runway with its length of 1.5 miles and area of 570,000 square yards. In this report, the shallow compaction effect and reduced ground vibration with the MVT are presented in comparison with the DDC which was utilized on the same project in a different area of the airport. INTRODUCTION MVT was developed by Fudo Tetra Corporation in the 1960’s and has been widely used in Japan (more than 14,400,000 square yards). For example, at the Kansai International airport, a large area including aprons was compacted with the MVT. It is capable of compacting up to approximately 5m in depth by using a heavy steel plate (3m x 3m) and a strong vibrator motor (V-180, 10Hz) on top of the steel thick plate with specified time duration. We were involved in densification work with the MVT at the Fort Lauderdale Airport Project (Figure 1) from June, 2012 to February, 2014. Deep Dynamic Compaction (DDC) was originally specified as the compaction method to secure the relative density over 70% in every 2,000 square yards grids, however, we proposed the application of MVT to reduce the vibration risk and it was accepted as the alternative (Figure 2). The compaction work was completed in February 2014, without causing any delay in regard to the residual settlement due to the high embankment (H=60ft=18m).

Jan 1, 2018

By M. Hesham El Naggar, Yasser Abdelghany

"ABSTRACT: The axial and lateral monotonic and cyclic behavior of helical pile foundations was investigated and new innovative helical screw systems suitable for seismic loadings were developed and patented. More than one hundred full scale field load tests were conducted on instrumented helical screw piles installed in cohesive soil. The piles included: plain helical screw piles (P-HSP); grouted (G-HSPs); fiber reinforced polymer FRP-G-HSPs; and reinforced grouted RG-HSPs. The RG-HSP piles axial capacity was more than twice that for P-HSP, with minimal reduction after cyclic loading, and their lateral capacity was more than 3 times the P-HSPs capacity. A 3-D finite element model was established. The results of 3-D finite element modeling were used to establish the load transfer mechanism and a design methodology for the considered piles.INTRODUCTION AND LITERATURE REVIEWHelical (screw) anchors have been utilized in tension loading and have gained popularity for bearing load applications. Helical piles represent an overall cost effective alternative to conventional piles for new construction and repair applications. The helical piles speed and ease of installation, less noise during installation added advantage with regards to their efficiency and reliability for underpinning including re-support and reconstruction of distressed and damaged foundations for either stabilization or rehabilitation. The “square shaft” SS175 pile is a segmented deep foundation system with helical steel bearing plates (helices) welded to a central steel shaft. Load is transferred from the shaft to the surrounding soil through these bearing plates. Segments or sections are joined with bolted couplings. Practically installed depth is limited only by soil resistance and economics. A helical bearing plate or helix is one pitch of a screw thread. All helices regardless of their diameter have a standard 75 mm pitch (Figure.1). The performance of single helical anchors and group action were studied experimentally and theoretically by several researchers, the researches focuses on the installation torque and uplift resistance. Some researches focus on the load carrying capacity with little pile response to cyclic loading effects or to instrumented full scale field testing. Helical piles axial compressive or lateral loading still is not well characterized and needs more analyses and their seismic performance was not investigated. For such this research was initiated to investigate the helical piles monotonic and cyclic performances under axial and lateral loadings to consider their usage in different applications in seismic zones. Among the several researchers, Clemence (1983); Mooney et al. (1985) conducted field and laboratory testing; Hoyt (1989), Hoyt et al. (1995), and Ghaly and Clemence (1998) conducted theoretical and experimental testing, Puri and Vijay (1984), Huang et al. (1995), Perko (2000), and Pack (2000) conducted theoretical analyses. Rao and Prasad (1993), Prasad and Rao (1994), conducted experimental testing; Vickars and Clemence (2000) studied the performance of helical piles with grouted shafts."

Jan 1, 2014

By Jiwei Duan

The deformation and load transfer behavior of a single soil-cement column are studied with the finite element method. The results show that there is an effective length for a soil-cement column. Beyond this length, the settlement of the column is approximately equal to a constant. The effective pile length is introduced to the concentric cylinder approach (Randolph and Wroth 1978), and an analytical formula for estimating the settlement of a single flexible pile is presented. A second analytical formula for determining the effective pile length of a soil-cement column is obtained and an example shows that the calculated and measured results are in quite good agreement.

Jan 1, 2002

By J. M. N. P. C. Teles, Venda Oliveira P. J., Correia A. A. S.

"AbstractA laboratory work was performed to study the mechanical behavior of a Portuguese soft soil chemically stabilized with binders and reinforced with metallic fibers when subjected to tensile stresses. To this end and in order to compare the tensile strength results done by two different tests, there were conducted two types of experimental tests: Tensile Split Strength Tests (TS) and Direct Tensile Strength Tests (T). The samples tested had the same binder quantity and different fiber contents, which allowed the characterization of the tensile behavior of the stabilized and reinforced soil, as well as the definition of the best fiber content. Results show that the binder is the main parameter controlling the behavior of the stabilized and reinforced soil until failure, while the influence of the fibers is noticed mainly at the post-failure behavior. The comparison between the tensile strength done by T and TS tests shows that the tensile split test can be used to estimate the tensile strength, although its results are lower than those obtained by the direct tensile tests in general.IntroductionDue to its poor mechanical characteristics, the construction on soft soils presents difficulties that require the use of soil improvement techniques such as chemical stabilization. However, even when mixed with binders, the tensile strength of the stabilized soil is poor, requiring, in certain cases, the use of expensive steel reinforcement or metallic beams, with obvious impact on the final cost of the work. Thus, for the cases where the tensile strength is a design requirement, the soil stabilization should be design with another element, whose primary role is to give tensile strength to the improved soil (Teles 2013).To fill the lack of published studies focused on soft soils both chemically stabilized and reinforced with metallic fibers, the present research aims to analyze the behavior of the improved soil when subjected to tensile stresses. To support the research there were conducted direct tensile tests (T) to directly measure the tensile strength of the samples and tensile split tests (TS) or Brazilian tests to obtain it indirectly. The samples tested had the same binder quantity but five different fiber contents in order to study the influence of the fibers in the improved soil behavior. In addition, a comparison between the results of both tests was made."

Jan 1, 2014