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By Hiren J. Shah

Across much of New York City, the geology of glacially deposited soils follows a common sequence. Outwash sands generally overlie varved silts and clays, which lie above a basal till deposit underlain by the bedrock. Pile foundations at projects with such typical stratigraphy generally develop their axial capacities by extending below the fine-grained deposits into the till or the bedrock. Contrastingly, at a project site on the Brooklyn waterfront, high capacity piles were efficiently and economically installed by driving them into the relatively shallow glacial drift and till deposits which lay above thick fine-grained compressible glacial lake deposits. An unusual aspect about the foundation design at the Brooklyn project site is that, relatively short and high capacity piles were driven into the shallow glacial drift and till deposits, overlying the thick fine-grained glacial lake deposits. In order for this unusual foundation scheme to be feasible and economical, the piles needed to achieve their driving criteria in the upper strata. Consolidation settlements in the lower stiff and over-consolidated glacial lake deposits below the pile tips had to be relatively small. The paper discusses the unusual stratigraphy in this area of Brooklyn in greater detail with geologic profiles and engineering characteristics of the glacial strata. It also discusses the design aspects of the pile foundations, settlement estimates, a pile drive test program during design, results of the static load test program during construction, and production pile installation results.

Jan 1, 2008

By Mohini Patel, Jahnavi Parmar, Pranav R. T Peddinti

Expansive clays pose a variety of geotechnical problems. Although the admixture stabilization is proven to address their problematic swelling and shrinkage characteristics, the influence of unsaturated condition on the engineering performance of these soils needs further research attention. In addition, highly saline soils with high organic content would further alter their performance. A similar soil stratum was encountered at the Gulf of Cambay, Bhavnagar district, India. High salinity in the in-situ expansive soil of basaltic origin and the prevailing unsaturated condition, enforces the engineers to look out for possible soil treatment methods. In this regard, the present work attempts to analyze the unsaturated behaviour of this soil when fly ash is used as an admixture. A comparative study for stabilized and unstabilized mixes is performed in terms of their unconfined compressive strength, electrical conductivity, swell characteristics and California Bearing Ratio.

May 1, 2022

By Ashley Shirer

Have you heard a geotechnical engineer rail against using the word "dirt"? The typical maxim is: "It's not dirt, it's soil!" This axiom is so prevalent that it is joked about on the construction site. How did we get to the point in our profession that soil is too technical to understand, while dirt is not viewed as important? Take a moment and think about the images that come to mind by the word soil. Responses range from the sand at a playground to the mud that sticks to the bottom of your shoe, the dark loam found in gardens to the firm earth under your feet. But do you know where the term soil originated? Or how it was intended to be used? This article looks at how word choice can lead to very different motivations for owners, designers and constructors.

May 1, 2023

By Joshua R. Omer

A numerical model is developed for predicting the load transfer and settlement behaviour of vertically loaded, bored cast in-situ piles. Based on analysis of full-scale pile tests, closed-form equations are formulated to uncouple the shaft and base transfer resistance components of the pile/soil system. Appropriate parameters are introduced to take into account: (i) the shaft resistance distribution in unlined and partially lined piles, (ii) the effects of ?soft toe? (voided toe pile) behaviour on base resistance development. For convenience, an interactive computer program has been developed in Matlab? with a user friendly interface system. The program can be applied to predict the complete load-settlement curve and axial force distribution in bored cast in-situ piles if reliable soil test data are available. To demonstrate its validity, the proposed method is applied to 4 test piles, which are also analysed using two previously published methods: (a) elastic solution method and (b) layer discretisation method. Methods (a) and (b) above are based on load transfer (t-z) and finite element models respectively. It is shown that the proposed method yields axial force distributions and load-settlement curves that are in good agreement with the observed pile test data.

Jan 1, 2010

By Hyunsuk Yoon, Kiho Lee, Juhyng Lee, Younghoon Jung, Junboum Park

"The environmental double pile method is presented as a device to improve the engineering properties and to clean up contamination of low-permeability soil. This method is one of the novel technologies based on the concept of one step process. It can be applied to low permeable contaminated ground for site reuse. It uses piles to improve drainage, contaminant remediation, and bearing capacity of the ground. To evaluate the on-site applicability of this technology, drainage and strength properties of the environmental double pile were assessed by a series of experiments and numerical analysis. Environmental double pile was found to be a feasible alternative method to improve contaminated soft ground.Korea is a peninsula with many coastal industrial zones. These zones are located in regions mostly underlain by soft ground with low permeability and adjacent to industrial areas that can be contaminated. Therefore, a new region-specific remediation method is required to achieve environmentally sustainable development. This research introduces the Environmental Double Pile (hereinafter, refer to as EDP) for the lowpermeability contaminated ground and focused on both contaminant remediation and soft ground improvement. Basically, the EDP is quite similar to sand compaction pile (SCP). The SCP has been studied extensively to improve soft ground (Braja 1999; Hansbo 1994; Madhav and others 1978; Taylor 1948). But unlike SCP, EDP is filled with oyster shells instead of sand and an inner pile is inserted in the center of this oyster shell filled-zone. Therefore, it is a double pile consisting of the oyster shell pile and the inner pile, as depicted in Fig. 1."

Jan 1, 2005

By S. Y. Zhou

Excavation with earth retaining is one of the main technological means in deep foundations and underground engineerings. Several construction methods which have been used in China are introduced here with some examples from engineering practices in Shanghai, including foundation pit protected by steel or RC sheet piling or D-walls, open caissons and pneumatic caissons, shield tunnel and pipe jacking, etc. This paper also discusses the prospect in development and utilization of underground space in China and the challenge to which the engineers specialized in deep foundations have to face.

Jan 1, 2010

By Yuji Yamashita, Kazuyoshi Kamimura, Tsuyoshi Takahashi, Naoya Matayoshi

"The CDM-LODIC method (cement deep mixing - low displacement and control) method enables ground displacement to be reduced by removing an amount of soil equivalent to that of injected cement slurry and the volume of the plunged mixing tool, which causes a certain degree of ground displacement. Since the CDM-LODIC method was developed in 1985, it has been applied to over 930 sites and the accumulated volume of stabilized soil has now reached 7.6 million cubic meters.In the CDM method, the number of blade rotations per unit depth in the ground when the mixing blades are withdrawn is considered a construction item. The blade rotation number depends on the degree of mixing between the cement slurry and the ground Some field tests were performed based on the degree of mixing between the cement slurry and the ground. In these tests, a new concept of evaluating the blade rotation number when the screw rod penetrates to a given depth without injecting cement slurry has contributed to the degree of mixing. Furthermore, a correlation exists between the coefficient of efficiency of soil removal and the cement slurry admixture rate. In this paper, we discus the data collected in those field tests and present some application examples.OUTLINE OF CDM-LODIC METHODThe injection of cement slurry may cause some ground displacement during Cement Deep Mixing (CDM). In recent years, due to an increased demand for ground improvement work in urban areas, there is increased concern that buildings near any CDM site may be adversely affected. The deep mixing method which reduces displacement due to mixing (CDM-LODIC method) enables ground displacement to be minimized by removing an amount of soil equivalent to the injected cement slurry and the volume of the mixing tool, which itself causes some ground displacement. When the construction site is near other structures, regardless of whether on or under the ground, the CDM-LODIC method can be used in order to minimize any ground displacement. There are considered to be two main causes of ground displacement as shown in Figure 1. Displacement A indicates ground displacement caused by the volume of the inserted mixing tool during the penetration stage and displacement B indicates ground displacement caused by the volume of the injected stabilizing agent. Thus, by removing soil equivalent to the volume of the inserted mixing tool and the injected stabilizing agent, ground displacement can theoretically be minimized. Figure 2 shows the amount of observed ground displacement in the cases of CDM and CDM-LODIC at an actual site. These case studies indicate that ground displacement can be reduced by removing the soil."

Jan 1, 2015

By Fabio Santillan, Michael F. Zoccola

"Wolf Creek Dam and Lake Cum berland in Russell County Kentucky is operated by the United States Army Corps of Engineers (USAGE) Nashville District It is a combination 3,940 ft long (1,200 m) non-zoned clay embankment, a maximum of 215 ft (65.5 m) above top of rock and 1,796 ft long (547 m) concrete gravity section. Built in the 1940s, the limestone beneath the embankment is characterized by an extensive interconnected network of solution feature; varying from fist size to largecaves.In 2005, studies conducted by the Nashville Distrect concluded that a new seepage cut-off wall was needed as the existing cut-off wall, installed in the 1970s, did not go deep enough and did not extend laterally far enough to intercept all major karst features The dam was classified as a ""Dam Safety Action Classification I (DSAC 1) – Urgent and Compelling,"" the highest risk under USAGE risk category rankings. Also in 2005, under a USAGE risk screening program of its entire dam portfolio, Wolf Creek was classified as a Dam Safety Action Classification 1-Urgent and Compelling, which put it in the highest category. In 2007, an Independent External Peer Review from outside USAGE, concluded there was compelling evidence that a piping failure mode had re-initiated and was in an ""advanced continuation"" stage of development.Impounding approximately 6 million acre-ft (7.4x102m3) of water at flood storage, Lake Cumberland is the largest reservoir east of the Mississippi River and ninth largest in the United States. Catastrophic failure would result in widespread flooding, Ices of life and economic losses in billions of dollars.In 2008, the Nashville District partnered with a joint venture between finns Treviicos and Soletanche (ISM through a ""Best Value"" contract to construct a new seepage barrier wall. This acquisition method was used in lieu of a low bid contract due to complexity of the work and dam safety concerns. It took advantage of the experience and innovation of contractors by soliciting technical proposals that were evaluated independent of cost. Those proposals deemed technically qualified and responsive then underwent a trade-off analysis between ccst and technical approach and a selection was made of the one deemed to give the best combination."

Jan 1, 2013

By Paul Summers, Kevin Richardson, Willem (Billy) Villet, Paul J. Sabatini, Attasit Korchaiyapruk, Edward C. Clukey

"A deep mixing method (DMM) foundation was selected by the Project Team for a very large LNG facility in West Africa. As described in a companion paper, this foundation consists of a large number of columns installed by mixing cement with in-situ soils. The foundations are arrayed as a variety of honeycombed type configurations which, if installed to desired specifications, can provide a robust foundation alternative. The foundation is capable of distributing loads and limiting settlements even if some of the soil in the columns is not fully mixed during installation. An important part of the overall quality assessment program, therefore, involved developing a testing program to verify the methodology. In addition the impact of potential defects in columns on the overall foundation integrity had to be assessed. This paper describes some of the preliminary work done to establish the requirements for the quality assurance program. A key component of this program involved the sampling frequency used to assess potential defects in the columns. To verify the column integrity 104- mm samples were taken continuously at a selected frequency through the 23 m long columns. The preliminary work described in this paper demonstrated that the appropriate sampling frequency depends on both the desired reliability level as well as the number of defective columns encountered during testing.Initial finite element analyses were performed to assess the extent that defects could occur in columns within the honeycombed structure without adversely affecting the overall foundation integrity. The results from this work demonstrated that the spatial location of the defects was critical to properly assessing the foundation integrity.In addition to column sampling a load test was performed as part of the foundation verification process. The methods used to apply appropriate loads so that loads at the bottom of the columns approached design values are discussed in the paper.The results obtained from this preliminary study were then used to help develop a more comprehensive assessment program, described in a companion paper, to determine the robustness of the DMM foundations for both the LNG processing facilities and a condensate tank.IntroductionFoundations constructed with the Deep Mixing Method (DMM) can be an attractive and cost efficient alternate to other deep foundation options. This foundation is constructed by mixing soil and cement with an auger type drill. The foundation is usually constructed with a dual auger system that simultaneously creates two contiguous columns called foundation elements. Many elements are then arranged in a honeycombed configuration to create the overall foundation (Figure 1). A desired column strength can be obtained by varying the volume of cement added to the columns, the mixing rate of the soil and stroking sequence."

Jan 1, 2017

By Edward C. Clukey

A deep mixing method (DMM) foundation was selected by the Project Team for a very largeLNG facility in West Africa. As described in a companion paper, this foundation consists of alarge number of columns installed by mixing cement with in-situ soils. The foundations arearrayed as a variety of honeycombed type configurations which, if installed to desiredspecifications, can provide a robust foundation alternative. The foundation is capable ofdistributing loads and limiting settlements even if some of the soil in the columns is not fullymixed during installation. An important part of the overall quality assessment program,therefore, involved developing a testing program to verify the methodology. In addition theimpact of potential defects in columns on the overall foundation integrity had to be assessed.This paper describes some of the preliminary work done to establish the requirements for thequality assurance program. A key component of this program involved the samplingfrequency used to assess potential defects in the columns. To verify the column integrity 104-mm samples were taken continuously at a selected frequency through the 23 m longcolumns. The preliminary work described in this paper demonstrated that the appropriatesampling frequency depends on both the desired reliability level as well as the number ofdefective columns encountered during testing. Initial finite element analyses were performed to assess the extent that defects could occur incolumns within the honeycombed structure without adversely affecting the overall foundationintegrity. The results from this work demonstrated that the spatial location of the defects wascritical to properly assessing the foundation integrity. In addition to column sampling a load test was performed as part of the foundationverification process. The methods used to apply appropriate loads so that loads at thebottom of the columns approached design values are discussed in the paper. The results obtained from this preliminary study were then used to help develop a morecomprehensive assessment program, described in a companion paper, to determine therobustness of the DMM foundations for both the LNG processing facilities and a condensatetank.

By Frank Rausche, Scott D. Webster, Rozbeh B. Moghaddam

"Pile foundation driveability is a function of several variables such as subsurface characteristics, hammer type, hammer efficiency, pile type, and plugging conditions. One important phenomenon occurring during pile driving, and yet not well documented and published, is the friction fatigue, where a reduction of shaft resistance is observed as the pile is driven to greater embedment. This paper introduces current soil models developed for the assessment of friction fatigue, and further presents a comparison between predicted driveability obtained from Wave Equation Analysis Program (GRLWEAP) and field driving records. From a literature survey, and review of technical articles, a widely-used soil model known as AH-01 has been selected to analyze the friction fatigue concept. Using a WEAP software, two driveability analysis were completed using the standard approach with setup factors, and adapting the AH-01 model into the WEAP input file. Driveability predictions were compared to the driving records corresponding to a 1676-mm x 44- mm open-ended pipe pile with a total and embedment lengths of 180-m and 119-m, respectively. Results from analyses and the comparison presented in this paper provide further information regarding existing methods for the incorporation of the friction fatigue concept to the driveability analyses, and contributes to a better prediction of driveability of open-ended pipe piles. IntroductionDynamic measurements during pile installation provide more dependable information as compared to results obtained from predictive models used for design. Despite uncertainties associated with a specific project site and foundation type, measured data provides a reliable understanding of the soil resistance and its distribution throughout the length of the pile. Back-calculations or back-analyses based on a series of measured data from a pile driving process could help to obtain reliable models to better predict events related to pile installation process in spite of all variability related to fitted models. One of the widely-used analysis regarding pile driving during the design phase is the “driveability analysis” where capacity, blowcounts, maximum stresses in the pile element, and transferred energy from the hammer to the pile element are predicted using mathematical models along with a software. Such analysis requires relevant information regarding soil, pile, and hammer properties combined with a deep understanding of the level of impact each one of these properties could have on the analysis."

Jan 1, 2017

By Garland Likins

The Texas Department of Transportation, now considering using Augered Cast-In-Place (ACIP) Piles (also known as Continuous-Flight-Auger or CFA Piles) in their foundations, awarded a research project to Professor Mike O'Neill at the University of Houston (UH) to study the advantages and potential difficulties with ACIP/CFA piles. ACIP/CFA piles were installed on three sites for UH; they had extra instrumentation and additional measurements by UH staff during installation which are beyond the scope of this paper. Independent visual logging of the pile was done by an experienced inspection firm. The main advantages of ACIP/CFA piles are their speed of installation and their economy. Potential savings are substantial. Disadvantages include an unknown structural condition of the shaft. Inspection is critical, but many simultaneous observations make accurate inspection difficult. Because of resulting uncertainty, many engineers have avoided ACIP/CFA piles in the past.

Jan 1, 1998

By George Burke

Of the three projects, particularly the extensive Nimitz II (downtown) project, a single system, which was part of the operation, was used to control the spoil. Spoil control was continuous with the work since a vacuum truck and crew was used to suck up the spoils as they came out of the borehole. So, the whole job was kept clean both during operations and at the end of the shifts. On the Sand Island project, a double system was used. Larger spoil quantities were contained within the shaft limits during the work and the cleanup or disposal of the spoils was performed during excavation.

Feb 10, 2003

By Shamsher Prakash

Estimation of vertical load carrying capacity of a single vertical pile under earthquake loading is an important task of a design engineer. Lateral vibration of vertical pile is highly influenced by the magnitude of vertical load. Several load reversal, during earthquake loading introduce gap between pile soil interface which reduces its load carrying capacity and increases lateral motion. This paper presents a simple time domain numerical scheme to estimate the lateral pile response, considering the loss of contact of pile at pile soil interface, during impact and earthquake loading. The motion of the pile is limited in the vertical plane. Time domain has been discretised into small intervals. The non linearity of soil properties has been taken into account by discretised Winklers model with Wolfes frequency independent mass spring dash pot coefficient for geometric damping. Suitable software has been developed which keeps track of the load reversal point of each elements.

Jan 1, 1996

By Mohamed A. Eliwah

This paper deals with the determination of hydraulic conductivity of the coastal coralline limestone aquifer of Jeddah, Saudi Arabia. This coastal area has witnessed urban development and establishment of towers which requires deep foundations, excavation and dewatering of huge quantities of unconfined groundwater. It is occupied with successive layers of soft detrital and consolidated massive cavernous coralline limestone of the Quaternary age. These layers are encountered at a depth of 1.5m and extend for more than 100m. Hydraulic conductivity values were obtained by analyzing the pumping tests data under steady and transient state conditions. Hydraulic conductivity values help in selecting the proper and safe dewatering system, as well as determination of discharge rates and quantities of groundwater to be withdrawn. Test results obtained from two surveyed sites showed that the values of hydraulic conductivity are greatly variable. It ranges between 118.1 and 1559.6 m/day at the first site, whereas at the second one it ranges between 94.6 and 350 m/day. These high values are attributed to the cavernous nature of the water-bearing formation. Jeddah city could be divided into three different dewatering zones extending from north to south parallel to the coast line. Well point dewatering system could be applied in the first zone while ditches and sumps are the most suitable dewatering method in the second and third zones. Dewatering using deep wells in such highly permeable formation will require withdrawal of huge quantities of water which will be accompanied by washing out fine sediment filling the cavities in the surrounding areas. This will badly affect the nearby buildings through settlement, crakes and other structural damages. Therefore, construction of grouting plug/blanket with thickness of 3.0 m at a depth of 20.0 m is recommended. This depth will be enough to support the plug against the hydrostatic pressure. Moreover, it is highly recommended to transfer the site into closed box, by using diaphragm walls or secant bored piles.

By Marcus Daubner

This paper explains how BAUER Spezialtiefbau GmbH uses digital methods on projects - starting from work preparation to completion of works. More precisely, the advantages of BIM-based planning during work preparation and the automated and structured data management - both machine production data and the manually recorded quality-relevant reports - during execution phase are displayed. In this context, the benefit of the digital twin to optimize processes, to reduce defect costs, for a more effective reporting sys-tem, and the further usage of as-built information in the BIM or GIS process is described.

Sep 1, 2022

By Chris Harnan, Christophe Justino

The European Federation of Foundation Contractors (EFFC) and the Deep Foundations Institute (DFI) jointly published Edition 1 of the ‘EFFC/DFI Guide to Support Fluids for Deep Foundations’ in April 2019. This Guide was prepared by a Task Group comprising experts on deep foundations from contractors, materials suppliers, consultants and academics. The Guide builds on work carried out by the Tremie Concrete Guide Task Group and presented in Edition 2 of the Tremie Guide. The Paper discusses and describes the content of the Support Fluids Guide which presents the state of the art on support fluid management, as well as the R&D work currently being carried out and funded by EFFC and DFI sponsors through an ongoing Field Research Study (FRS) as well as a review of academic research linked to the EFFC/DFI joint effort aimed at improving knowledge and guidance on support fluids. The FRS and academic research will help to improve the understanding of relevant support fluid properties including stability of excavations, interface layer formation, effect of filter cake and the development of new sampling and testing methodology. The Paper also presents the initial findings from the FRS program as well as a discussion on the challenging aspects of support fluid management with emphasis on design, performance, testing, and the environment.

May 1, 2022

By Gianni O. Chieruzzi

A 400 MW, gas-fed power plant on floating piles and piled raft foundations was constructed in the Province of Moskovskaya, Russia in 2008. The subsurface is characterized by fill underlain by loose to medium dense alluvial deposits, with peat and clay interbeds, a stiff to hard, highly plastic, silty clay stratum of glacial origin, and a stratum of very dense, varved interbeds of sand and silt. More than 800, drilled concrete piles were constructed at the site. The pile length ranged from 15 to 23 meters below existing surface grade, and the pile diameter ranged from 0.9 to 1 meter. Initial analyses by others predicted total power plant settlements of 3 to 4 cm when subjected to the permanent loading conditions. Under a peer review process for the equipment supplier, subsurface investigation and testing were performed to verify the consolidation parameters used for foundation design of the power plant foundation. The parameters obtained in this investigation were used in the 3-D finite-element model ELPLA as inputs for the settlement analysis of the turbine building and power island. The ELPA analyses predicted settlements on the order of 7 cm over a period of 30 years. The actual settlements after two years of monitoring were compared against the model predictions. The rate of settlement and the recompression index were both underestimated in our model. The measured settlements have enabled us to calibrate both of these model parameters so that the model better matches the data.

By Alireza Ayoubian, Douglas S. Roy, Gianni O. Chieruzzi

"A 400 MW, gas-fed power plant on floating piles and piled raft foundations was constructed in the Province of Moskovskaya, Russia in 2008. The subsurface is characterized by fill underlain by loose to medium dense alluvial deposits, with peat and clay interbeds, a stiff to hard, highly plastic, silty clay stratum of glacial origin, and a stratum of very dense, varved interbeds of sand and silt.More than 800, drilled concrete piles were constructed at the site. The pile length ranged from 15 to 23 meters below existing surface grade, and the pile diameter ranged from 0.9 to 1 meter.Initial analyses by others predicted total power plant settlements of 3 to 4 cm when subjected to the permanent loading conditions. Under a peer review process for the equipment supplier, subsurface investigation and testing were performed to verify the consolidation parameters used for foundation design of the power plant foundation. The parameters obtained in this investigation were used in the 3-D finite-element model ELPLA as inputs for the settlement analysis of the turbine building and power island. The ELPA analyses predicted settlements on the order of 7 cm over a period of 30 years. The actual settlements after two years of monitoring were compared against the model predictions. The rate of settlement and the recompression index were both underestimated in our model. The measured settlements have enabled us to calibrate both of these model parameters so that the model better matches the data.IntroductionA 400 MW, gas-fed power plant was constructed near Moscow in the Province of Moskovskaya in Russia.Figure 1 shows the general arrangement of the main structures, and the geometry of the piles supporting those structures."

Jan 1, 2017

By Eric J. Pederson

The down hole hammer is widely used in specialty geotechnical construction. The common uses include tie-back anchor installation, micropile installation, and general soil/bedrock drilling operations. Veit used these techniques to develop a cost effective way of installing the foundation system for University of Minnesota Football Stadium. The soils present at the site of the stadium contained layers of concentrated cobbles and boulders. The geotechnical engineer recommended a driven pile system, and the base bid outlined in the project documents consisted of an H-Pile using a 14x73 pile section. Veit submitted an innovative alternate consisting of using a rotary percussion system to install a 12? O.D. pile. This paper will show that this pile type and installation method was the correct choice for the project. The design criteria for the compression, uplift, and lateral capacities and deflections were met, while eliminating pile damage. The method resulted in a significant cost savings to the University and maintained the project schedule.

Jan 1, 2008