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By Hui Yongning

This paper presents a simulating test of constitutive relation of soil anchor in laboratory and puts forward a new plastoelastic mechanical model, on which a new calculating formula of elastic and plastic limit bearing capacity for soil anchor is suggested and two engineering projects verify that this method is adaptable.

Jan 1, 1991

By Joseph C. Gillen

This paper discusses the design, construction, and performance of the support of excavation system used at The Atlantic Building jobsite. The support of excavation system had to be adaptable to the different conditions surrounding the site. These conditions included support of four historic building façades, including the nine-story Atlantic Building, as well as support of three historic row-houses along two walls. Directly adjacent to the site is the historic Ford?s Theatre and townhouse. Across a 15? alley is the American Immigration Lawyers Association (AILA) Building, and across a 30? alley is the Federal Election Commission Building and another ongoing excavation. Of historical note, these two alleys were the escape route for John Wilkes Booth following his assassination of President Lincoln. With the excavation being 53? to 58? deep, the system included driven and drilled soldier piles, drilled bracket piles, and two modified tangent walls. The bracing included tiebacks, corner braces, wales, cross lot struts, and a specially designed support system for the nine-story façade. The footprint of the excavation included 12 corners and all alleys and streets were to remain open during construction. The performance requirements for system movement at Ford?s Theatre and AILA Building were ½ inches in the horizontal direction. The modified tangent walls were used in these areas to provide stiffness. The soil conditions at the site were fill material on top of a shallow, sandy, silty, gravel layer on top of a deep layer of soft organic silt and clay. Below the silt and clay layer was fine sandy material at the subgrade.

Jan 1, 2006

By Paul J. Axtell

This case history describes the foundation design and construction for the New Mississippi River Bridge, presently under construction in St. Louis, Missouri. The 1,500 ft (457.2 m) main span of the cable-stayed bridge is supported by two delta tower pylons in the river, with anchor piers on each bank. The final foundation design was completed as a part of an Alternate Technical Concept (ATC) proposal by the winning construction team, and utilized drilled shafts up to 11.5-ft (3.5-m) diameter that were socketed into very hard limestone. As part of the ATC foundation design, a full-scale, bi-directional static load test was performed to verify the design and allow use of higher resistance values. This paper presents the results of the site exploration, construction of the load test shaft, details of the load testing, and a comparison of the test results with various design parameters.

Jan 1, 2011

By Donald A. Bruce

"Abstract The Deep Mixing Methods (DMM), in their current forms, have been employed in the United States since 1986, although an earlier version had seen service from 1954. The earlier developments were strongly influenced by practices in the Nordic countries and Japan, while by the late 1980’s several DMM systems had been developed in the U.S. itself. Since then, DMM has continued its evolution, principally via the challenges of a series of large, landmark projects, but also via distinct, significant technological advances. This paper highlights the key points in the history of DMM in the U.S., and provides an overview of the different methods currently in use.In the BeginningIt is a common misconception that the history of applications of the Deep Mixing Methods (DMM) in the United States dates from 1986 when SMW Seiko Inc. — a subsidiary of Japan’s Seiko Kogyo Company — was established in the Bay Area. However, the author believes that Intrusion Prepakt Co.’s patented MIP (Mixed in Place) system had been used, albeit sporadically (about 30 projects are recorded), since 1954 (FHWA 2000, 2001). Ironically, by 1961 this single auger method had been extensively used under license in Japan for excavation support and groundwater control — by the Seiko Kogyo Company. By 1972, the original MIP technique had been succeeded by more advanced Japanese methods, involving multiple augers. Intrusion Prepakt have long since become defunct.The first systematic studies of contemporary Deep Mixing Methods in Japan began in 1967 when the Port and Harbor Research Institute of the Ministry of Transportation began laboratory testing using granular and powdered lime for treating soft marine soils. Fundamental studies continued through the early 1970’s, by which time the development of industrial scale equipment was well advanced, having its first application on a marine trial near Haneda Airport. Coincidentally, laboratory and field research also began in 1967 in Sweden (“Swedish Lime Column Method”) for treating soft clays using unslaked lime. Reportedly the progenitor was a Norwegian, Kjeld Paus, who had made observations on fluid lime columns in the U.S. It would seem that developments in Japan and the Nordic countries proceeded independently until 1975 when the technology leaders from each group (Broms and Boman; and Okumura and Terashi, respectively) presented their — very similar — findings at a conference in Bangalore, India. Limited technical exchanges ensued thereafter.Whereas the Nordic developments continued to focus on the use of dry reagents (cement and lime) and relatively light equipment compatible with operating on and in very soft clays and organics, the Japanese progressed into the use of fluid reagents (cement-based grouts) and heavier equipment for both marine and land-based projects. Thus, by 1986, there were a large number of proprietary (wet and dry) DMM systems in Japan, and a rapidly growing market already by then accounting for over 12,000,000 m3 of ground treatment."

Jan 1, 2014

By Sun Jiale

This paper presents a brief description of information construction technology for supported excavation to assure satisfactory performance of engineered system. As a successful example of application of the technique, quite a few troublesome problems, such as high groundwater level in soft ground and crowded buildings around the excavation, were solved satisfactorily in the construction of the new tower of Guangzhou Overseas Chinese Manison.

Jan 1, 1991

By Zachary Q. Maassen

The purpose of this paper is to highlight the environmental benefits of properly managing slurry waste as it is generated on site. The following projects will be used to illustrate the importance of proper onsite waste management. Project: Jet Grout Backflow Dewatering The goal was to dewater the backflow directly onsite to produce a dry, solid waste and reusable water. The backflow spoil was pumped directly to the dewatering system as it was generated. Utilizing mechanical separation equipment and flocculation polymer the waste volume was reduced by 44%. Due to the site footprint and high volumes, slurry waste removal and onsite processing were the only two feasible options. Onsite dewatering proved to be the environmentally beneficial option as it eliminated the need for slurry waste hauling and disposal. The benefits of utilizing a dewatering system are listed below: Project: Soil Mixing Spoil Recycling for Slurry Wall Construction In this application the spoils generated contain bentonite mud, cement mixture and organic ground soils. The goal of this project was to process the backflow mixture to recover reusable bentonite mud and separate the soil as a dry, stackable waste product. The treatment system replaced the traditional method of vacuum truck extraction and facility disposal. The environmental benefits of properly handling the backflow is a decrease in fresh water usage, bentonite additive reduction, and the reduction of CO2 emissions. The paper will consist of a project scope, technical equipment and process description, environmental impact reduction calculations and lessons learned for each project.

Jan 1, 2018

By John S. Pack

The last 25 years have seen rapid expansion in the use of helical screw pile foundations and tiebacks for new and retrofit construction of buildings and earth retention structures. An estimated $100 million was spent in 2002 on helical foundations and tiebacks in the United States alone. While design information is available in the literature, information regarding quality control, inspection and performance monitoring is lacking. Recognition of at least one manufacturer's helical foundation material by the Uniform Building Code, Standard Building Code, and BOCA (all three codes now combined into the ICC International Building Code) has given added urgency to the dissemination of reliable and practical quality control, inspection and performance monitoring procedures. This paper describes a set of such procedures that have been followed for 17 years by engineers experienced in the industry who have directly installed or been involved in the installation of over 140,000 helical foundations and tiebacks in divers soil conditions for various types of structures, including earth retention structures. Topics covered include design responsibility, building code listings and requirements, manufacturer ISO certification, manufacturing process, material and installation specifications, installation contractor certification, field placement, installation procedures, field inspection, building code inspection and performance monitoring. The paper concludes with a step by step example of practical quality control, inspection and performance monitoring procedures on a typical helical foundation project.

Jan 1, 2003

By N. C. Matheson

The West's Shell Pile has been used on sites with very soft ground conditions for over 60 years. Fibre reinforced precast concrete shells 900mm long are threadled onto an internal mandrel which can be extended according to the depth driven to attain the load bearing resistance. On completion of driving the mandrel is removed leaving the precast shells to form a permanent lining to the cast insitu concrete core. To give resistance to high contamination, a tar based epoxy coat is sprayed on the outside of the shells or a flexible PVC liner is installed inside the shells to protect the core. Fundamental to the resistance to contamination is the quality of the precast fibre reinforced concrete shell, the mix design and method of manufacture. A series of detailed laboratory experiments were carried out using samples immersed in concentrated acid and sulphate solution. The long term effects of exposure to contamination is recorded in the case studies of existing piles at two gasworks sites.

Jan 1, 1989

By William Babcock

Augered, Cast-In-Place (ACIP) piles can be an economical, reliable, versatile foundation system. They have also been a part of projects that were behind schedule and the subject of lawsuits. The ACIP pile is a specialty system that is more workmanship dependent than most deep foundation systems and is especially vulnerable to the problems and abuse of poor specifications and contract language. Many of the original specifications were based on grouting methods, and numerous misconceptions have followed the method. The Deep Foundations Institute (DFI) has been the leader in debunking the mystique that has hovered over the method and attempted to standardize the industry through publication of the manuals describing the method and how it should be inspected. DFI should be applauded for taking the lead and producing a reference document that can be used to educate the specification writers, designers, inspectors, and owners. It must be must appreciated that there have been other organizations that would not acknowledge ACIP piles as a legitimate member of the deep foundation family. Some consultants and designers have gone to the extreme of making it policy to not recommend the method for use. This presentation is one practitioner's view of the causes of problems as they can be traced back to the contractual conditions. It is intended to provide a broader and different perspective than those provided by the technical specialists. It does not necessarily reflect the position of the DFI or any of the organizations associated with the ACIP pile industry. It is intended to further the spirit of partnering on every ACIP pile project, to further the acceptance and promote the use of this unique system, for the benefit of all the parties. It should be recognized, however, that all of the participants can and do play a role in getting a project into trouble. My view is that projects that get into trouble usually have an early flaw that leads the project to the edge, and the project participants blindly follow the original mistake right over the cliff like lemmings. This instinctive reaction may be a survival tactic by going along with the group, because any one party that departs from the program or shows a position of weakness is a candidate for sacrifice.

Jan 1, 1997

By Samer R. Rabab?ah

As part of the PHX Sky TrainTM project at Phoenix Sky Harbor International Airport in Phoenix, Arizona, the existing traffic lanes at the 44th Street underpass below the Union Pacific Railroad (UPRR) Bridge will be shifted to accommodate the people mover guideway. The proposed reconfiguration and reconstruction of 44th Street required the utilization of micropiles and permeation grouting to resist the lateral forces induced by cutting into the slope below the existing bridge abutment footing. This paper discusses the evaluation of the existing bridge abutment, including analysis of the original foundation system, and design, installation and testing of a new micropile-supported retaining wall to support the cut slope below the existing bridge abutment foundation. A monitoring program was implemented during construction to evaluate the short- and long-term performance of the bridge abutment. Instrumentation included survey monitoring points, inclinometers, tiltmeters and crack gauges. A micropile load testing program was conducted to verify design assumptions concerning micropile axial and lateral loading. Numerical analyses (using PLAXIS software) were performed to predict the short- and long-term behavior of both the abutment wall and the bridge foundations. Movement data collected from the monitoring program indicate that the wall and bridge foundations are performing satisfactorily and within the general bounds of predicted movements. The results from the numerical modeling using PLAXIS software showed that the proposed solution is deemed adequate to provide the needed global stability with an acceptable factor of safety, along with acceptable deformation.

Jan 1, 2011

By Lok M. Sharma

"Construction of a new bridge in a seismically sensitive area requires careful assessment of earthquake impact on the serviceability of the facility. Not only is the superstructure vulnerable, the foundations play a key role in the bridge’s survivability. A new bridge in eastern part of the state of Missouri in the U.S.A. is located in a seismically active area and hence subject to additional thrust on the foundations and superstructure and potential damage due to liquefaction. An eleven span bridge with foundation soils varying from shallow bedrock to over 30 m (100 feet) overburden soils were considered for the bridge support piers. Two of the bridge support bents located within the flood plain area through over 30m (100 feet) of alluvial deposits were considered most affected by an earthquake event due to the additional thrust and lateral ground spreading. This paper describes the determination of site specific seismic hazard, numerical modelling of the foundation system, and methodology of dynamic analyses, effects of lateral spreading and liquefaction potential on bridge support bents. From numerical modelling using FLAC, the increase in thrust on piers and deformations were computed to predict the behavior of the foundations.INTRODUCTIONA newly constructed bridge on route US 40 crosses the Missouri River west of St. Louis, Missouri and upstream of Mississippi River in mid-west USA. The west abutment area has near surface bedrock while the east abutment area has overburden deposits over 30m (100 feet) thick, mostly river sediments comprising of silts, lean clays and sands overlying bedrock. Softer layers of silts and sands in the east river bank area are assessed to be liquefiable during a high magnitude earthquake event. St Louis area has a potential for a high magnitude earthquake due to the New Madrid Fault some 160km (100 miles) south. The bridge foundations were designed as drilled piers, 2 m (8 feet) in diameter and socketed into the bedrock. Bents No. 10 and 11, located in the lower flood plain area of the river, are considered to be most affected by a seismic event.In order to perform dynamic analyses of the foundations, earthquake ground motion time history was developed for the specific site using a Probabilistic Seismic Hazard Analysis (PSHA) and selecting and scaling of a recorded time history. Relying on the U.S. Geological Survey (USGS) Earthquake Hazard Program for the PSHA and AASHTO Guide Specifications for LRFD Seismic Bridge Design, spectral acceleration values for the site were developed. The spectral acceleration values were for a 7 percent probability of exceedance in 75 years (1000 year return). Numerical modelling using FLAC computer program was performed. This paper presents the seismic design parameters, methodology used in the dynamic analyses, static and dynamic analyses, impact and mitigation of liquefaction on Bents 10 and 11 and the abutment fills, and effect of lateral spreading on the foundations in the lower flood plain area of the bridge. From the numerical modelling, increase in thrusts on pier foundations and estimated deformation were computed."

Jan 1, 2017

By Walter I. Paniagua

Drilled shafts and precast concrete piles were installed for the foundation of several structures in a reconfiguration project of a refinery in Minatitlan, Veracruz, in the Gulf of Mexico. The soils are alluvial deposits of flat land from the Coatzacoalcos River, which are embedded with layers of sand, soft clay, and peat. As part of a QC/QA program, load tests, both static and dynamic, axial and lateral, were performed. In this paper results of 32 axial tests are presented, in which typical load-displacement curves were measured at the top of the foundation elements; from the interpretation of these plots, data were recorded for ultimate side shear and in some cases for end bearing capacities, which are compared with the theoretical results of the final stage of the foundation design. The comparison shows that under allowable loads, side shear determines the bearing capacity of piles, even when the tip is embedded in a hard layer. Underestimation of the side shear is evident; therefore design criteria, as well as the methods used for obtaining soil parameters, should be reviewed.

Jan 1, 2007

By Maurizio Siepi, Fabio Santillan, Lyndon Bedford, Carlo Crippa

"Abstract: Wolf Creek dam, on the Cumberland River in Kentucky, US, operated and maintained by the Nashville District of the USACE, is the Corps' largest reservoir east of the Mississippi river. The 1748 m (5,736 ft) long Wolf Creek dam combines earthfill and concrete gravity sections. Construction began in 1941 and was completed in 1950. The dam showed signs of instability in the 1960’s, and in the late 70’s an in-depth project of rehabilitation was undertaken, using both grouting and secant piles. The works saved the dam, but in the late 90’s further signs of distress worried the Nashville district of USACE which, after a study conducted on the water seepage, concluded that construction of a new concrete barrier cut-off wall was needed. In 2009, the $341.4 USD million contract was awarded to TREVIICOS-SOLETANCHE JV.The new wall, located upstream of the concrete monoliths, has a minimum thickness of 60 cm (24 in.), and runs the length of the embankment, into the right abutment, for about 4,200 feet. The founding depth reaches 84 m (275 feet), well below the zone of solutioning. With a total surface approaching 92,903 sq.m (1,000,000 sq.ft), the Wolf Creek barrier wall is unlike any other project in the world.The construction of the cut-off wall followed a complicated but logical sequence of several operations, involving a variety of technologies: grouting, hydromill, directional drilling, and secant piles with reverse circulation. The intensive rock grouting program was aimed to minimize the risk of slurry loss and extend the positive cut-off further deep. Subsequently, an Encasement Concrete wall was installed with hydromill, toeing into the rock, to protect the embankment during the following phases. Smart holes were then drilled into the Encasement wall down to the final depth. Eventually, the holes were used to install the secant piles by employing the reverse circulation piling method.An extensive verification campaign has confirmed the superior quality of the cutoff wall consisting of 1200 secant piles, exceeding by far USACE’s requirements. The main project was substantially completed in early 2013. A small portion of secant piles wall will be installed downstream of the dam, to close the switchyard, finishing the project in the early months of 2014.IntroductionWolf Creek Dam is located on the Cumberland River in south-central Kentucky. The Nashville District of USACE operates this multipurpose dam to provide hydropower, flood control, water supply, and water quality benefits for the Cumberland River system and surrounding region. Lake Cumberland, created by the dam, impounds 7,400 million cu.m (6 million acre foot) at its maximum pool elevation of 232 m (760 ft) above sea level. This lake is the largest reservoir east of the Mississippi and the ninth largest in the United States, and attracts 4.89 million visitors, more than Yellowstone National Park (2.87 million).This paper describes the recently completed works for the rehabilitation of the dam, accomplished by TreviICOS-Soletanche JV with the construction of a new Barrier Wall."

Jan 1, 2014

By W. Y. Xu

In comparison with shallow foundation, usually higher bearing capacity, smaller average settlement and better stability are the engineering characteristics of pile foundation. Besides, a smaller differential settlement and a lower settlement rate which will converge quickly are more important characteristics. The superstructure of the building with pile foundation may not meet with significant differential settlement. In this paper, settlement records and other data of different kinds of buildings are chosen to illustrate the characteristics of pile foundation. Moreover, some technical problems in connection with foundation engineering solved in consideration of the above mentioned characteristics of pile foundation are also introduced.

Jan 1, 2010

This work shall consist of furnishing and driving foundation piles of the type and dimensions designated on the plans or in the special provisions including cutting off or building up foundation piles when required. This specification also covers providing test piles and performing loading tests. Piling shall conform to and be installed in accordance with these specifications, and at the location, and to the elevation, penetration and bearing capacity shown on the plans or as directed by the Engineer. Except when test piles are required, the Contractor shall furnish the piles in accordance with the dimensions shown on the plans or special provisions. When test piles are required, the pile lengths shown on the plans are for estimating purposes only and the actual lengths to be furnished for production piles will be determined by the Engineer after the test piles have been driven. The lengths given in the Engineer's order list will include only the lengths anticipated for use in the completed structure. The Contractor shall, with-out added compensation, increase the lengths shown or ordered to provide for fresh heading and for such additional length as may be necessary to suit his method of operation.

Jan 1, 1989

By Colin Curtis

In recent years, Manchester Airport has undergone expansion including the construction of a second runway, a new terminal building (Terminal 3) and extensions to the existing Terminal 1. Manchester is Britains third largest airport and ranked 20th in the world for international traffic. Arup (Manchester) was engaged as consulting engineer in a multi-disciplinary role for the terminal works. Part of this was a geotechnical commission including site investigation and pile design followed by supervision. This paper reviews the piling for the old, new and terminal extensions. In total, five pile types have been utilised over the years. The original 1950's Terminal 1 was founded on driven cast in situ piles, with a later 1970's extension utilising rotary augured piles. The recent piling comprised continuous flight auger piles (CFA), driven steel tube and tripod bored; the latter in areas of restricted access or low headroom. The ground conditions are Made Ground over thin Alluvial and Glacial drift, in turn, over a generally weak to moderately weak gypsiferous mudstone. All the piles were socketed into the mudstone. In terms of the new CFA piles, quality control using the instrumentation monitoring was problematical, but a substantial static load and integrity test programme resolved pile performance. Part of the work is matching new pile performance with previously installed piles and the continued use of older piles with new loads. Research provided some data on the older piles, including some static load test data, which enabled back analyses of their design and likely behaviour. Differences in design methods, installation techniques and pile behaviour based on load tests will be discussed.

Jan 1, 2001

By W. J. Kingwell

My comments and questions are addressed to Mr. Troughton. It seems to me that the tests were very well tailored to determine long term effects on performance of bearing piles as groundwater pressures rise in the London Basin. This rise is being simulated by means of a groundwater recharge system but it would be informative to have further details of the controls of conditions simulated. Ideally the porewater pressure in Standpipes 1, 2 and 3 should be the same throughout the test. Under test conditions are there not practical dif­ficulties? Recharge Well C2 is a lesser dis­tance from the pile than the other wells. Was the rate of recharge to C2 regulated to a lesser rate than the other three? In my experience the rate of acceptance usually varies from well to well. Under a common feed pressure were mea­sures taken to compensate for this? Since the problem does not only affect London, but also Liverpool, Nottingham, Birmingham and to a lesser extent, Manchester, I question whether an ideal procedure is being used. It is well known that rates of acceptance decrease with time and often recharge wells need to be flushed out at regular intervals. Other pro­cedures may need to be adopted to accurately simulate the effect of groundwater rise, if tests of longer duration are to be considered.

Jan 1, 1991

By Jason Weck, Alper Turan, Ali Chehadeh

"Rapid expansion of urban areas dictates the need to expand/rehabilitate the existing buried infrastructure at the same rate. The technical challenges such as variable soil and rock profiles, high groundwater tables and limitations imposed by the built environment combined with present fiscal and schedule limitations necessitates the implementation of fast and cost effective construction methods. Since drilling procedures and equipment allow the construction of overlapped pile systems in almost all subsurface conditions, the secant pile walls have become a cost-effective shoring option for such infrastructure expansion/rehabilitation projects. The secant pile walls constructed in a circular plan layout to form a vertical shaft provide unique advantages since they act as a compression ring. Secant pile walls require stringent drilling tolerances be achieved in order to provide structural support and to work as a compression ring in addition to a groundwater cut-off wall.This paper outlines design methodology, installation procedures and verification techniques used for the secant pile compression ring for the Waterloo Landfill Pumping Station No.2. The secant pile compression ring had a 6m inner diameter with over a 20m wall depth and over 18m excavation depth. The details of subsurface conditions, analytical and numerical methods used in design are presented here. The details of the monitoring system are introduced and results of monitoring are presented and compared with analytically estimated and numerically simulated quantities. The results presented in this study are considered to be of interest to those involved in design and construction of vertical circular shafts."

Jan 1, 2014

By F. H. Chen

the Rocky Mountain Region since 1950, drilled pier foundations have been widely used to combat structural movement problems in expansive soils. It is now an accepted practice for engineers to use drilled pier foundations in expansive soil areas. Piers are generally drilled into bedrock in a zone unaffected by moisture change. With some exceptions, such system has successfully prevented damage incurred in the structures as the result of soil expansion. In the last 15 years, no significant advancement has taken place in the design of the drilled pier system on expansive soils. Numerous failures continued to be reported. Causes for the failures were placed on poor drainage, inadequate void under the grade beams or mushrooms on top of the piers. Engineers realize that these are certainly not the major problems. The basic design criteria should be critically reviewed. It is the purpose of this paper to point out the actual problems confronted by designers, the failure module and remedial measures, The writer does not claim to have the solutions. In fact, it will be a long time before real solutions can be found, yet the writer believes the engineering communities, the construction industry and the general public should be aware of the true picture of the problem.

Jan 1, 2010

By Stan Merjan

Composite piles with precast concrete tapered pile tips (TPT Composite Piles - U.S. and foreign patents) are a new and important addition to the piling types available to the construction industry. TPT Piles were invented by Stanley Merjan, Vice President of Underpinning & Foundation Constructors, Inc.. U. F. C. installs these piles in the Northeast United States and licenses piling contractors in other parts of the country. TPT Piles have been developed for use in sandy subsoils at depths to 70 feet or greater. The TPT system (see Figure 1) is simple. A pile stem of conventional material (shell, pipe, steel, wood, precast concrete) is connected to a socket formed in a precast concrete tapered pile tip (TPT). This composite assembly is then driven as a unit by ordinary pile driving methods until adequate driving resistance (established by formula or load tests) is met in a suitable soil strata. This driving resistance develops from the displacement and densification produced by the TPT. Many combinations of tip shapes and stems are available to suit particular job requirements with respect to subsoil conditions and pile capacities. TPT Piles should be considered for use on a wide variety of jobs. The advantages offered by a TPT installation include: ? High capacity piles in marginal soils ? Minimal lengths required to produce these capacities ? The use of conventional pile driving equipment and procedures ? Pile inspection techniques that are the same as for ordinary pile driving Furthermore, TPT piles are economical due to a combination of a low cost per ton of pile capacity and high productivity, both of which lead to significant savings in foundation costs and time required to complete foundation work.

Jan 1, 1987