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By Arpit Parikh

"Ground Water or Pore water pressure development in Sandy Soil formation is Critical situation in foundation analysis and design.Moreover it become severe while associated with higher liquefaction probability in river bank areas. It is difficult to find cost optimized solution for liquefaction mitigation under limited budget allocated for the project. Here in these research paper the attempt has been made to have clear picture of liquefaction by using various techniques and field tests. And its mitigation by suitable foundation type. In Bangladesh, On Bank of River Meghana, Power plant structures are proposed. The particular site is full of fine sand having partial silt throughout from EGL to 55 m depth. Hence in addition to Conventional Boring / Drilling operations, CPLT, SCPT, SCHT and PMT had been performed to arrive deterministic effect of liquefaction. By use of Geologismiki software and some excel based programs developed which indicates that Certainly liquefaction occurs under the event of earthquake. By Checking past records of Bangladesh we found, there are small magnitude earthquakes are inevitable and frequent. Hence fourth to overcome the bad effect of liquefaction, the deep pile foundation -Driven Pre Cast Solid Square Pile of 400 mm dia. had been suggested for various types of power plant structures. Which densify the soil and ground will improve in resisting liquefaction.1. INTRODUCTIONA Detailed Geotechnical/Foundation design Analysis had been done to arrive at optimum foundation design solution in highly probable liquefaction zone of Silty Fine Sand near Dhaka City of Bangladesh for proposed 750 MW Cyclic Power Plant. Hence about 24 no. of (Borehole) Boring and Drilling up to depth of 55 m from existing ground level has been carried out. Additionally, 09 nos. of Static Cone Penetration Test (SCPT), 02 Nos. of Dynamic Cone Penetration Test (DCPT), 02 Nos. of Pressure meter test (PMT), 02 nos. of Cyclic Plate load test (CPLT) of suitable capacity with 06 nos. of Seismic Cross Hole Test (SCHT) in boreholes had been carried out. The purpose of PMT and SCHT was to have clear idea about the Seismic behavior - knowhow of site. According to Basic principles of Soil Mechanics and foundation design, it is proved that PMT & SCHT are dynamic test. These tests stimulate field condition of occurrences of earthquake. In later stages of analysis, it is found that site have high probability of liquefaction through use of Geologismiki – Liquefaction Analysis Software. Author of these research paper also felt earthquake vibrations – strong aftershocks during site study where Epicenter of the earthquake was in Myanmar during month of august 2016."

Jan 1, 2017

By Michael A. Knott

Large lateral forces on bridge foundations due to extreme events such as vessel collisions, earthquakes, and wave forces on storm surges during hurricane events are often the controlling design condition for bridge foundations. A review of the American Association of State Highway and Transportation Officials (AASHTO) vessel collision analysis and design codes used in the United States for highway bridges will be presented. The paper includes the background and development of the AASHTO Guide Specification and Commentary for Vessel Collision Design of Highway Bridges (1991) and vessel collision provisions of the AASHTO LRFD Bridge Design Specifications (3rd Edition 2004 and the approved 2005 Interims). Experience in using the AASHTO codes will be discussed and observations on the adequacy and gaps, comparison with the European Standard Code, and recommendations for immediate and long term needs will be presented.

Jan 1, 2013

By Fabrice Mathieu

The Cutter Soil Mixing (CSM) provides a cost effective solution for the rapid construction of retaining and cut-off walls using new equipment developed from diaphragm wall cutter technology. CSM consists of cutting and mixing drums mounted on compact hydraulic motors. Soletanche Bachy CSM has been designed to leave the space above the tool free, thereby mixing the soil efficiently during all the phases of the wall construction, with high penetration rates. The precise positioning and verticality of the wall is achieved using a kelly bar and full monitoring. Soletanche Bachy CSM is a versatile equipment which can be mounted on various carriers: pile rigs, hydraulic crane, carrier equipped with telescopic mast. The major phases of Soletanche Bachy CSM development are presented, including the results of an extensive trial carried out in Le Havre (France). The soil consists of hydraulic fill with soft soil lenses overlying sandy deposits. 20m deep panels were constructed to support a rectangular shaft. During the construction, and after its completion, the shaft was subjected to an extensive series of tests followed by a partial excavation. The paper discusses also the future development of the technique and its potential applications.

Jan 1, 2006

By Dean E. Matthews

The concept of a pile for construction is credited to a Neolithic tribe called the "Swiss Lake Dwellers" who lived in what is now Switzerland about 6,000 years ago. They used piling, not for supporting heavy loads as we do today, but for elevation to protect themselves from wildlife. The Romans often used piles, and built many structures, including buildings, homes, bridges, roads and viaducts on piling. The Romans built the first bridge across the Tiber River in Rome on timber piles in B.C. 1620. Homes in the cities of Venice and Ravenna were built on piles from B.C. 100 to A.D. 400. The Romans also built the first bridge across the Thames River in London in A.D. 60 on timber piling.

Jan 1, 2003

By Alan J. Lutenegger

Some years ago, a method was developed to incorporate a grout column around square-shaft helical screw-piles and anchors to increase shaft buckling resistance under compression loading. An additional benefit of this grouted shaft is to increase the load capacity in both compression and tension, depending on the geometry of the lead helical section and the soil conditions. Because of the unique construction procedure, the contribution of the shaft to the total capacity has largely been unknown. The behavior of grouted shaft helical anchors in clay was investigated by performing full-scale axial uplift (tension) load tests on a series of anchors installed at the University of Massachusetts Geotechnical Test Site. In order to isolate the contribution of the grouted shaft to the total load capacity, anchors were installed with a wooden dowel connection between the lead helical section and extension sections on three of the four anchors so that only the shaft resistance would be measured during the load tests. The grouted shafts ranged in length from 10 to 30 ft (3 to 9 m). Initial tests were performed approximately 5½ months after installation. Nearly four years after the initial tests were performed, the tests were repeated to evaluate any significant change in capacity with time and/or repeat testing (preshearing). The soil conditions at the site are presented along with the load-displacement curves for both the initial and repeat teats and a discussion of the analysis of the results. Repeat load tests showed an increase in capacity from the initial testing, however the percent increase was not the same for all depths. The results demonstrate that considerable shaft resistance can be developed in clays from the grouted shafts as might be expected. Depending on the L/D ratio of the shaft and the contribution of the lead helical section, at working loads the shaft capacity can dominate the behavior.

Jan 1, 2011

By Raymond J. Castelli

The paper provides a general overview of the numerous types of earth retaining systems currently available, and organizes these various systems by several classification methods. These classifications can be used as a guide in identifying the appropriate type wall or walls for any specific project application. As a further aid in sorting through the numerous wall alternatives for a specific design or construction project application, the paper suggests a systematic approach for wall selection, and presents helpful charts summarizing the general advantages and disadvantages, and typical limitations for the currently available wall systems.

Jan 1, 2003

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 Ramdane Bahar

"Abstract The design foundations can be performed using Menard pressuremeter rules that require a limit pressure and a pressuremeter modulus. In recent years, another trend of interpretation of this test is appeared. It consists of identifying the rheological soil parameters using analytical or numerical methods and then used to evaluate the bearing capacity and settlement of soil foundations using numerical software. This paper deals with the bearing capacity and settlement predictions of bored piles using two approaches. The first one is the method called ""Pressident"" which is a numerical program developed to analyse pressuremeter tests taking into account the Duncan and Chang model. The second approach is the method developed by Bahar and Olivari based on the generalised elastoplastic Prager’s model with the Von Mises criterion which is suitable to describe the behaviour of saturated clays under undrained conditions. The pressuremeter data, collected on various research and consulting projects are used to explore the relationship between limit pressure and undrained shear strength obtained by the two methods. Numerical calculations, by FLAC2D software taking into account the rheological parameters derived from these two methods, are performed in order to predict the behaviour of a single bored pile subjected to an axial vertical load. The predictions are comparedto the measured data.IntroductionThe Menard Pressuremeter test has been used extensively to measure in situ soil properties and for the design deep foundations in Algeria. These tests are an useful and economical way for obtaining reliable in situ properties of soils and provide the measurement of in situ stress-strain response of soils. From this test, the design foundations can be performed using pressuremeter rules that require a limit pressure, pl, and a pressuremeter modulus, EM. These two parameters are derived from the pressuremeter curve or deduced from existing correlations with undrained cohesion and internal angle friction (Ménard, 1957; Amar and Jézéquel, 1972), and are used to evaluate the bearing capacity of soil foundations and the expected settlements. But, they can also help to identify usual soil parameters required by simple constitutive models for soils in numerical calculations."

Jan 1, 2014

By L. F. Miao

Studies were carried out to investigate the ultimate soil pressure acting on pile(s) undergoing lateral soil movement in soft clay. A special apparatus has been designed to apply a uniform rectangular profile of lateral soil movement on the rigid pile(s) with pinned head and tip conditions to obtain the ultimate soil pressure. The piles were 16 mm (5/8 in) in diameter. For the pile group tests, the behavior of different number of piles (2, 3, 4, 6 and 9), pile arrangements and center-to-center spacings (3 and 6 diameters) were investigated. In this paper, the group factors of 11 combinations of number of piles, pile arrangements and pile spacings are presented. The group factors are given for individual piles in a pile group as well as for the entire group. Generally, the group factors of individual piles in a group varied significantly according to pile spacing in both directions, and pile arrangement; the group factor of the whole group reduced with an increasing number of piles, and increased with increasing pile spacing. For a pile group with the same number of piles but different pile arrangement, no significant difference was found in the group factors for the entire group.

Jan 1, 2008

By Mark M. Petersen

As part of the addition of eight new combined cycle generating units at the Florida Power & Light Sanford Plant, 2,129 piles were to be installed. The existing plant elements were supported on driven piles, and the variation in pile lengths during previous work, as well as available subsurface information, indicated a complex stratigraphy. At the request of the owner, the designer/construction manager developed a program to evaluate the use of pressure-grouted displacement piles. A pre-design load test program in areas that represented the apparent extremes in subsurface conditions indicated that the system was feasible; however, the presence of existing features that were to be demolished later precluded the clear delineation of subsurface conditions in advance of construction. A contract was negotiated with the pile installer based on the best estimate of potential pile lengths, with modifications to pile lengths to be set based on additional exploration. A total of 52 cone penetration soundings and five load tests were performed immediately prior to and during pile installation to establish correlations between the CPT data and pile performance. Pile depths were set based on these correlations. Pile installation was completed 6 weeks ahead of schedule and 15 percent under the original budget estimate. This paper documents the evaluation of pressure-grouted displacement piles as an emerging technology, and illustrates the benefits of a close working relationship between the owner, designer, and pile contractor at a site with variable subsurface conditions.

Jan 1, 2002

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 Alun J. Davies

This paper describes a design-build project for the construction of a tanker wharf for 150,000 dwt vessels. The tankers deliver oil from offshore oil fields to a Transshipment terminal on the south coast of Newfoundland. The project described is an expansion to a previously constructed facility, adding an additional berth. The first berth was designed conventionally as concrete structures supported on groups of independent, single piles. The second berth was awarded to Peter Kiewit Sons' Co. Ltd. based on an alternate design which utilized a "jacket" concept whereby prefabricated steel frames are placed on the seabed and serve as permanent templates and also give lateral support to the piles, thereby increasing their load capacity. This led to economies and time savings. Discussed herein is the design process and the field installation, covering the jackets, driven pipe piles, and the rock anchors.

Jan 1, 2000

By Peter Jackson

The dewatering of the large construction pits required for major infrastructure projects often has a significant impact on the environment. This is particularly so in urban areas and where groundwater resources are of interest. These environmental impacts are inter alia, groundwater lowering and the consequent effects such as settlement and deterioration of timber foundations, together with the impact of the dewatering on the groundwater quality. In order to minimise the environmental impact of the dewatering, the quantity of water to be abstracted and the amount of groundwater lowering in the surrounding area must be minimised. This paper describes the measures that have been taken on the Copenhagen metro project to achieve the objective of minimal environmental impact whilst still carrying out a major dewatering scheme.

Jan 1, 2000

By Ketan H. Trivedi

This paper describes the method of analyses used for the design of temporary and permanent Secant Pile Walls, describes various aspects of construction including, guide walls, sequence of pile installation, plan alignment and verticality tolerance, methods of drilling (auger, wash boring, cased and open holes), lateral bracing for secant piles, cutting of keys in secant pile walls for the connection of permanent floor slabs, sealing of water leaks and waterproofing. The paper concludes with a brief case history of a secant pile wall project recently constructed in New York City.

Jan 1, 2006

By James J. Cahill

Contractor's working in an urban environment face a multitude of working conditions. There is no typical "Downtown" job site. From afar we just see the skyline, or up close a specific building. This, of course, does not give us a clue as to the site conditions the foundation contractor faced in doing his work. The open, downtown building site is still available on some projects, but they are becoming rare as our cities are becoming more developed. A typical site today might include any one or several of the following problems: A. Deep pit with no ramp access B. Multi-type known or unknown obstructions C. Height limitations D. Load restrictions E. Existing adjacent building founded on shallow foundation F. Existing foundations G. Existing tunnels, utilities or subways

Jan 1, 1991

By Walter Ensinger

Working safely means working cost-effectively. Every "dangerous occurrence" and - even more so - every industrial accident causes disruptions in the planned course of construction. Besides moral and legal obligations, economic aspects are therefore also factors motivating increased efforts towards optimal prevention: improvements in work safety and protection of health are wise investments! Ever since its earliest days, the European Federation of Foundation Contractors (EFFC) has made this subject one of its key objectives and therefore set up a Safety + Environmental Working Group, in which experts from the member organisations exchange national experience and develop proposals for "best practices". The paper presents current developments and results from the work of the S+E WG with particular reference to the project "Ideas for Safety Improvement".

Jan 1, 2006

By Allan Sylvester

Construction of the Shot Tower Metro Station in Baltimore, Maryland was performed in two phases. In the first phase, a contractor was retained to excavate the station in order to construct twin tunnels from the Shot Tower Station to the John Hopkins Station. The retention system for this 70' deep excavation consisted of a Soldier Pile in Tremie Concrete (SPTC) wall supported by cross-lot bracing. In phase two, The Clark Construction Group, Inc. was retained to construct the station interior structure, two entrances, two station ancillary shaft structures and the track work for the station and tunnel. The excavation for the construction of the two entrances adjacent to the 70' deep station SPTC wall had to proceed prior to completion of the station structure due to the tight construction schedule. A system of overlapping secant piles was specified as a vertical support of excavation element for the West Entrance. The secant piles would have provided a watertight, rigid support to resist the load from the SPTC wall constructed in phase one. A watertight system was required in order to minimize the settlement of adjacent buildings supported on wood piles. Clark Construction was concerned with the constructability, cost and performance of the specified secant piles and looked for other innovative methods of providing a watertight and rigid system. Substitution of a reinforced slurry wall in lieu of the secant piles was cost prohibitive due to the additional cost of concrete placed under tremie. Clark, being familiar with cement-bentonite cut-off walls and slurry wall construction procedures, proposed the construction of a PSHG wall, in lieu of the secant piles. The PSHG wall construction consisted of trenching 30" wide by 20' long by 60' deep panels under a self-hardening slurry. Once the excavation for a panel was completed, a 60' deep prefabricated soldier beam and lagging panel was placed in the slurry. The slurry design mix then self-hardened within the cure time, allowing excavation for the structure to proceed This paper will discuss the design, details and construction methods used on the PSHG wall and will compare the advantages of the PSHG system to conventional support systems.

Jan 1, 1997

By R. T. Stain

Dynamic methods of load testing piles using a drop hammer to generate the input force have been in use for many years. These systems are based on the wave equations developed at the Case Institute of Technology, Cleveland, Ohio in the late 1960's and are well documented. Such tests are generally restricted to preformed driven piles, the driving hammer being a convenient means of generating large input forces. In 1979 the CEBTP (France) was sponsored by the FNTP (Fédération Nationale des Travaux Publics) to undertake research into existing classical methods and to develop a test that would be equally applicable to bored cast in place piles. The result of this research programme is a methodology known as SIMBAT, and which was included in a series of class A prediction trials in Belgium in 1987 (Refs 1 & 2, Paquet 1987, 1988). The purpose of this paper is: a) to examine the type of 'dynamic'/'static? load test correlations that can be obtained. b) to highlight the differences between the classical' methods and the 'SIMBAT' technique.

Jan 1, 1989

By G. Tamaro

The World Financial Center is situated on a 60,000 square meter site at Battery Park City at the southern tip of Manhattan Island. The foundations for the buildings and the related infrastructure posed difficult design and construction problems since the site was filled land in the Hudson (North) River. Foundation construction was made difficult by both the geology and the existence of two railroad tunnels which passed under the site. The soils at the site were unsuitable to support construction of heavy structures, and as a result, all of the foundations had to be carried down to bedrock, or the glacial till over rock. Two buildings were supported on piling and special battered caissons which provided lateral support against wind loading. The other two buildings were supported directly on rock, requiring excavation to depths of 19 meters (63 feet) below grade.

Jan 1, 1989

By Joan Stoupa

The expansion of the West Point wastewater treatment plant located in Seattle, Washington, will require a permanent tieback retaining wall to enlarge the plant site for the new treatment plant facili­ties. The retaining wall will extend approximately 3,000 feet along the property boundary between the treatment plant and the neighboring Discovery Park. Wall heights will range from 35 to as high as 65 feet. The purpose of the retaining wall is to provide a more uniform grade on the plant site and to resist lateral pressures exerted by the upslope, unstable hillside. During preliminary design of the retaining wall, various wall systems were evaluated based on assumed subsurface soil conditions. Results of preliminary studies indicated that expected subsurface conditions and wall heights made a permanent tieback retaining wall feasible. However, uncertain loads on the wall and the capacity of anchors in the native soils were significant. As a result, a detailed geotechnical program was conducted. The scope of the program included conventional drilling, sampling, analyses, and a field test program to determine site-specific anchor capacities. This paper describes the anchor test program and results.

Jan 1, 1990