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By A. B. Desai

The construction of 1144 nos. of piles, each 1.5 m diameter, bored-cast-in-situ type and varying in depths from 6.5 to 23m, has been completed as foundation for 26 piers of 548 m long aqueduct across Orsang river to carry 1128 m3 water of Narmada Main Canal of the Sardar Sarovar Project in Gujarat. These piles are socketed 1.5 m into foundation grade rockmass. The portal system of 44 nos. of piles and pile cap at the top for each pier is analyzed considering the portal fixed at bottom of piles. The borings for pile shaft were done deploying reverse mud circulation rigs and also by conventional chiseling and bailing operations. Besides vertical loading tests and lateral loading test on piles, dynamic tests such as low strain integrity testing on 290 piles and high strain pile testing on 17 piles were also conducted. The results indicated that (a) the settlement/ displacement are much less than the prescribed limits (b) good quality of concrete (c) piles are firmly socketed and (d) piles have adequate structural capacity to withstand the design load.

Jan 1, 1996

By Ziyad Abunada, David O’Connor, Abir Al-Tabbaa

"Abstract Contaminated land remediation using soil mix technology (SMT) is a relatively recent development which has been shown to be a cost effective and versatile system with numerous environmental advantages over other remediation techniques. The added complexities and variability associated with contaminated sites has escalated the need for field trials, field monitoring and specific QC measures to be undertaken for this setting and was the rationale behind project SMiRT (Soil Mix Remediation Technology). The main aim of project SMiRT was field validation, testing and assessment to provide stakeholder confidence in SMT and increase its uptake for land remediation in the UK. The field trials involved the treatment of 800 m3 of soil, through applying six different remediation techniques with four different SMT systems and introducing over thirty binders and binder compositions with a range of installation methodologies. Various issues were faced during the installation process and which were addressed on site. This paper presents some aspects of early age field observations, field monitoring, in-situ testing, coring and laboratory testing of cored samples and highlights some lessons learnt, providing valuable information on the issues that need to be addressed for this application of SMT.IntroductionAlthough soil mix technology (SMT) was developed in the 1960s in Japan and Sweden for geotechnical applications, its potential in geo-environmental applications became evident more recently the 1980s in the US and in the 1990s in Europe, having since increased to provide a range of remediation systems (Al-Tabbaa and Evans, 2003; Al-Tabbaa et al., 2011). The most common applications to date have been (a) the construction of low permeability containment walls or cut-off walls to contain a contaminated site; (b) stabilisation/solidification (S/S) treatment, with cementitious binders, for physical and chemical encapsulation of contaminants in soils and (c) the installation of permeable reactive barriers (RPBs), which are permeable walls that intercept the groundwater flow and remove contaminants from it, by mixing special additives with the native soil. Contaminated land remediation using SMT is a cost effective and versatile approach with numerous technical and environmental advantages over other remediation techniques. These advantages include the use of simple and well established techniques and equipment, speedy implementation, applicability to sites of any size and to multiple contaminants, elimination of off-site disposal, low risk and low emissions. There is a lack of competing alternative technologies that offer the same level of versatility and economic, environmental and social benefits, under current environmental legislation constraints. In addition, most currently available contaminated land remediation techniques are only partially effective, and are relatively contaminant-specific. This makes SMT a promising and timely contender to lead the market place in offering a cost-effective, efficient and low risk solution to contaminated soil and groundwater remediation and has resulted in a range of recent innovations."

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 Anne Lemnitzer

Full-Scale cyclic field testing was performed on a 3x3 pile group consisting of nine cast-in-drilled-hole (CIDH) reinforced concrete shafts and a comparable single-shaft in order to investigate group interaction effects. Both specimens were constructed with pile diameters of d = 0.61m (2 ft), fixed head boundary conditions, and placed in stiff clayey soil at a test site near the LAX Airport in Southern California. Internal instrumentation was installed in the single pile as well as in three piles within the pile group to obtain pile curvatures. External instrumentation controlled the lateral displacement of the specimens. A combination of experimentally and analytically obtained p-y curves for the single pile was used to simulate results for piles located in the group when field data were not available. All test specimens were tested to structural failure and excavated after test completion to investigate pile damage and plastic hinge formations. Calculated group interaction factors ranged between 1.0 at very small displacement levels of <2.5 mm (0.1 in), 0.8 at the initiation of the pile-soil-pile interaction, i.e. between 4 mm - 15 mm (0.16-0.6 in), and increased towards 0.9 near structural failure (displacement >25 mm or 1 in). A literature set of p-multipliers was found to reproduce an accurate fit to the available load displacement test data from the group.

Jan 1, 2010

By Masaki Kitazume

"Abstract The wet type and dry type of deep mixing methods have been developed and widely applied for on-land and marine constructions in Japan. The quality assurance (QA) of the methods has been usually carried out by unconfined compression test on field stabilized soil sampled by core boring in Japan. In some other countries, stabilized soil excavated by the wet grab sampling instead of core sampling is often subjected to unconfined compression test for quality assurance. There are several merits and demerits in each method, but few studies have been carried out to compare the stabilized soil strength of these two types of specimens to discuss their applicability to practical construction. The author has conducted a series of field and laboratory tests to compare the stabilized soil strength and discuss the applicability of wet grab sampling to QA for wet and dry types of deep mixing method.In this study, the wet grab sampling was carried out at two road embankment construction sites where the wet type and dry type of deep mixing were applied. The cement stabilized soil was excavated at the three depths by a wet grab sampler soon after the DM column construction. The test result is compared with the other test data in the previous study to discuss the applicability of the web grab sampling method for QA of cement stabilized soil.IntroductionThe Deep Mixing Method (DMM), an in-situ soil stabilization technique using cement and/or lime as a binder, is often employed to improve soft soils (Kitazume and Terashi, 2013). A variety of factors and their interactions affect the eventual strength of a deep-mixed column, while some of which are controllable (e.g. binder type and dose) by engineers while the others are not (e.g. soil types, ground temperature, etc.; Babasaki et al., 1997). In addition to laboratory mix tests, which in essence are a parametric study to estimate the influence of these factors on a particular soil’s strength, the quality assurance (QA) practice in Japan usually involves unconfined compression test on sampling cores from the stabilized columns after a given curing period. It has been recognized, however, that the ‘field strength’, or the strength of the retrieved core, quf is on average lower than the ‘laboratory strength’, qul, evaluated by laboratory mix test. Also allowing for the inevitable variability, existing guidelines (for example, PWRC, 2004 and CDIT, 2008) recommend the design quf /qul values of, for example, 0.5-1.0 for the CDM (Cement Deep Mixing; a wet-type technique, in which binder is added as slurry) and 0.2-0.33 for the DJM (Dry Jet Mixing; a dry-type technique, in which binder is added as powder)."

Jan 1, 2014

By Lok M. Sharma, Deep K. Khatri, Bradfield. Brett

"A shored enclosure was required to access a control structure upstream below the dam of a deep lake. The shoring involves the interaction of the structure, soil, and water and the loads imposed include the hydrostatic forces of the water, soil pressures as well as dynamic forces due to currents and waves. Deep excavation support systems have traditionally been designed using classical methods that involve direct computations of earth pressures. However, traditional analysis does not take into account soil-structure interaction. Numerical modelling offers better means to analyze soil-structure interaction. This paper presents a 2D finite element (2D-FE) analysis of a deep excavation support structure that was required to remove and replace a control structure at the upstream toe of a dam. The sheet-piling shoring was designed to withstand the lateral pressures from 14 m deep free water and 5.5 m deep excavation below the free water to reach the required excavation level to replace the gate structure. Elastic-plastic analyses were performed to predict the stresses and deformations of the complicated shoring structure and excavation bottom. The soil parameters, procedures used to develop the 2D-FE model, and the results are discussed in this paper. The shoring system is currently under construction.INTRODUCTIONA deep shoring system enclosure is required to keep out water and soil and to provide a support for unbalanced loadings due to dewatering and/or, excavation in order to permit construction of the permanent structures in the dry. A braced shoring system consists of a single wall sheet piling which is driven into the ground to form a “box” around the excavation site and is braced on the inside. After bracing the sheet piling, seal concrete is placed into the bottom to prevent water from seeping into the open excavation from underneath the sheet piling, and the water is pumped out to provide the dry work area. The braced shoring involves the interaction of the structure, soil, and water and the loads imposed include the hydrostatic forces of the water, soil pressures as well as dynamic forces due to currents and waves. Deep excavation support systems have traditionally been designed using classical methods that involve direct computations of earth pressures, (active, passive, or apparent pressures). There have been some uncertainties regarding the actual distribution of earth pressures due to influence of the support wall flexibility, as these traditional methods do not take into account soil-structure interaction. Numerical modelling offers better means to analyze soilstructure interaction."

Jan 1, 2017

By Shreyas Giridharan, Fursan Hamad, Sujith Gowda, Christian Moormann

"Pile installation in soil is a dynamic process which exhibits large deformation in the soil region. Experimental investigation of pile installation is both time and resource intensive. Numerical investigation can be a helpful tool for the analysis of the installation process. Furthermore, numerical analysis allows simulating various soils and loading conditions with ease. Finite Element Method (FEM) – a widely used framework for numerical simulations - fails to perform well for soil mechanics where large deformation and heavy material movement exists. In order to alleviate this shortcoming, Material Point Method (MPM), advancement to FEM has been used. In MPM, material points (particles) are used to represent the domain which carry the information and move over a fixed computational mesh where the governing equations are solved.In the present work, a variation of MPM, called CPDI (Convected Particle Domain Interpolation) is utilised which handles large deformation problems better than the classical MPM. Here, the material points are represented by a spatial domain which deforms according to the particle deformation. This eliminates stress oscillations while particles cross the grids. Implementation is validated and applied to pile installation in dry and saturated soil conditions. A 2D axisymmetric model is chosen, with penalty function method being used for evaluating contact between soil and pile. Sand is modelled via the hypoplastic constitutive description that takes into account large deformation, as well as small strain stiffness. From these simulations, various parameters like stress, void ratio and friction angle are studied.INTRODUCTIONOffshore piling is challenging in terms of testing and execution. Before the execution, predicting an efficient installation method requires study of various parameters, like soil conditions, type of loading, force requirement etc., and are the minimum parameters to be known beforehand. To obtain these parameters, testing a real scale prototype under different conditions is not feasible. Scaled model tests in lab can support in making certain decisions, but fail to replicate real behavior fully. Therefore, the need for a numerical simulation technique emerges, which can provide early predictions easily and accurately. This later can be extended to real scale tests, reducing the number of experimental investigation required.Simulation of displacement pile installation in sand involves large deformation due to penetration process, thereby making the application of FEM impossible, where large deformation causes heavy mesh distortions. Due to this, meshless methods are developed to treat large deformation in a better way. Among various meshless methods, Material Point Method (MPM) shows more applicability to geomechanical problems. This is mainly due to the ease of handling soil, structure and water in a unified manner."

Jan 1, 2017

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 Nikolaus Schneider

"Abstract: The combination of failure in joints of diaphragm walls and their exposure to water pressure may have far reaching effects ranging from water leakage to the risk of catastrophic loss of stability for the retaining wall and civil structures behind it. Investigations of imperfect joints in diaphragm walls have led to the development and testing of a quality tool to monitor the joint integrity of diaphragm walls during construction. By applying independent mechanical sensors (“joint inspector”) to the steel frame of hydraulic or mechanical grabs, it is now possible to record the surface conditions of exposed primary joints during the construction of secondary panels. This allows for the implementation of corrective action during the construction process should joint quality not indicate a watertight connection to the adjacent panel. The joint inspector, used for different types of stop ends, was tested on a full scale test field at several construction sites. The implementation of this new quality tool drives a new quality standard for deep excavations in inner city areas.General introduction to diaphragm wallsDiaphragm walls are reinforced concrete elements constructed using bentonite slurry to temporarily support an open trench in the ground. They are used in two main fields of application in civil construction, as foundation elements for vertical and horizontal loads (barrettes) and as retaining walls for excavation pits.Particularly for deep excavation pits in inner city areas, diaphragm walls are used as temporary or permanent walls of retaining walls. Alternative retaining wall systems would be secant pile walls, sheet piles or soldier piles, but these have disadvantages in structural strength when compared to diaphragm walls. If the vertical load of existing buildings next to the excavation pit has to be accommodated, the most practical solution can be found using diaphragm walls supported by prestressed anchors, steel struts or slabs."

Jan 1, 2014

By Bengt Fellenius

The conventional wave equation analysis without control of the representativeness of the parameters to the actual conditions does not provide accurate results. However, the representatives can be vastly improved by means of using the results of monitoring the dynamic response in a pile during driving. Dynamic monitoring displays the interaction of independent strain and acceleration measurements having directly propor­tional response to impacts, but inversely proportional response to re­flections from the soil. Examples are given and the CAPWAP method used to calculate from the measurements the dynamic pile and soil para­meters and mobilized soil resistance is outlined. The dynamic monitoring technique and analysis has been accepted internationally and been incor­porated into Building Codes. The prediction is offered that in five year&apos;s time, no major piling project will be undertaken without dynamic monitoring and analysis.

Jan 1, 1984

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 C. T. Christensen

The paper gives an outline of the design, installation and performance of a series of mooring and berthing dolphins for a major ferry berth outside the port of Elsinore, Denmark. The Dolphins are large cylindrical bottle shaped and open ended steel piles vibrated into the sandy seabed. They are subsequently equipped with prefabricated fender units. Vehicle access to the ferry is via a fixed ramp and a semi-submerged linkspan. Supplementary passenger access is via a covered gangway steel bridge from an existing gangway facility to a midship door in the ferry«

Jan 1, 1989

By A. K. C. Chan

Recent hotel investment projects in China often involve very tight programmes for design and construction. An example given in this paper involves a 24-storey reinforced concrete hotel tower with 460 bedrooms and a 3-level podium commercial complex. The building is supported by relatively widely spaced columns and shear walls below which 88 number large diameter piers were excavated through fill, silty and bouldery clay on to dolerite and slate at depths between 15 to 3 0m below ground level. Whereas much experience has been accumulated in Hong Kong, hand-excavated pier foundation was only adopted for the first time in Dalian. This paper describes and discusses the various factors influencing the choice of the type and design of the foundation system. The criteria for determining appropriate founding levels are then explained. During installation, revisions to the acceptance procedure were made to cater for local conditions. Emphasis is placed on the role of the geotechnical engineer in making on-site decisions during construction. The advantage of the foundation system in accommodating on-site changes resulting from local complex ground conditions is demonstrated. The pier foundations were successfully completed ahead of programme.

Jan 1, 2010

By Sun Shao Xian

The Port of Shekou is situated at Shenzhen Bay on the east side of the Pearl River estuary. Geological condition of the site is quite complicated. On top of the sea bed, there is a layer of soft silt 8 - 14 m thick. Under the soft silt, there are intercalated layers of sand, silt and clay. Average surface elevation of the underlying undulatory weathered bed rock is about - 20 m, with a variation of about 10 m. In certain locations, the weathered bed rock is covered with a layer of silt 3 - 4 m thick. This paper gives brief account of three types of wharf structures which are of particular interest, constructed in the last few years: (A) Platform type wharf structure with frontal sheet piling and steel raking pile in the rear; (B) Relieving Platform type structure with steel sheet piling and inclined anchoring HP pile ; (C) Steel pipe pile row supported apron added to a marginal quay. Average construction time of a deepwater berth is about six months.

Jan 1, 1991

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 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 Jesús E. Gómez

In the Summer of 2011, emergency repairs to the Jefferson Memorial North Plaza and Seawall were completed. These repairs were necessitated by settlement and lateral movement of the seawall and North Plaza which prompted the National Park Service (NPS) to initiate an investigation as to the possible causes of the movement, and commission a design for its mitigation. Information gathered from extensive instrumentation on site led to the design of a movement mitigation scheme that included demolition of the Ashlar Seawall and reconstruction of a new seawall. The new seawall foundation is an A-Wall consisting of vertical caissons and battered pipe piles connected to the seawall itself. The scheme provides resistance to future vertical and lateral movement of the North Plaza and the new seawall. Repair to the seawall and plaza began in December 2009, and was completed in August 2011. This paper discusses the mechanisms believed to be responsible for settlement and lateral movement, summarizes the procedure followed for design of the mitigation, and describes the construction methods and some challenges faced during the repair.

Jan 1, 2011

By Fritz J. Klingler

From site demolition, to design, to construction, Detroit&apos;s new Tiger Stadium project is required to be completed within a short 2 ½ years from award of the design-build contract. Such extreme schedule requirements together with somewhat difficult ground conditions at the site, resulted in several challenges in the design and construction of the deep foundation system for the stadium. During the geotechnical investigation, an intermittent water bearing sand layer was encountered overlying the hardpan at the site. As a result, some concern developed regarding the potential for collapse of caisson bells within this layer, as well as the potential for flooding of the caissons during drilling. Although sand and/or ground water was encountered within about half of the caissons, standard drilling and belling methods were used, and adverse conditions were controlled in almost all cases through expeditious drilling, inspection and concreting of the caissons. This paper will present a summary of the ground conditions, design and specification requirements, and construction methods used to successfully install the caissons for this project.

Jan 1, 1999

By Theodore R. Maynard

The history of foundation engineering in Chicago is a tale of innovation, made necessary in order to keep pace with structural technology which allowed taller buildings with heavier bearing loads, to accommodate a non-conducive geologic setting. The geology as it relates to foundation construction and underground construction in general is briefly described. A chronology of important events from the birth of Chicago to the present is presented. The impact of various construction techniques which were either initiated or refined to allow the growth of Chicago are discussed. Introduction The growth of Chicago resulting in today&apos;s high-rise high-density population center can be looked upon as a history of modern underground construction. The two major reasons which explain this are 1) It grew up during a period of rapid development in the Industrial Revolution and 2) Its natural geological setting needed a great deal of innovation for continuing growth.

Jan 1, 1991

By Bernard H. Hertlein

All methods of deep foundation construction present challenges to the contractor and engineer that vary according to the method employed, and the geotechnical conditions in which it is being used. Augered-Cast-In-Place (ACIP) piles are generally regarded as one of the most challenging, because the construction method precludes the use of traditional shaft inspection and quality control techniques. Application of Nondestructive Test (NDT) methods can provide quality control for ACIP shafts that traditional methods cannot, but each NDT method has limitations. These make some NDT methods unsuitable for use on ACIP shafts, and may limit the effectiveness of others, depending on geotechnical conditions. To help contractors and engineers working with ACIP piles select the test method most appropriate to specific site conditions, this paper presents a summary of the major NDT methods currently available, and reviews their capabilities with respect to the unique conditions presented by ACIP pile construction. Case histories illustrate how a combination of careful method selection, skilled data interpretation, and experienced engineering judgment have resolved problems and ensured quality in foundation construction by discriminating between potentially serious defects, and those that are unlikely to be significant.

Jan 1, 1997