Search Documents

By George Machan

Bitumen coatings have been successfully used to significantly reduce downdrag on piles. Thicker coatings of "soft" bitumens can accommodate downdrag so well that very little downdrag load is transferred to the pile. Many of the case histories describe better than 80 percent downdrag load reduction. Bitumen coatings have been used on several projects in Oregon. On the Mocks Bottom Bridge project (see Reference 1), experimentation and instrumentation confirmed the viability of bitumen coatings and provided insights for design and construction. Subsequent bridge projects have used this information and have raised issues to be resolved.

Jan 1, 1989

By Edmund J. Cardoza

The Detroit Water and Sewerage Department (DWSD) provides water and wastewater services to the Greater Detroit Metropolitan Area. Sewerage is treated at the DWSD Wastewater Treatment Plant (WWTP) located at 9300 W. Jefferson Street south of the City of Detroit, Figure 1. PARTICIPANTS Engineering and design of the project for the DWSD was performed by Harza Engineering Company, Inc., C.C. Johnson & Malhotra, P.C. and their sub-consultants, including Worley Engineering and Wade Trim. The Prime Contractor is a Joint Venture of Traylor Brothers, Inc. and Jay Dee Construction. The shaft drilling and riser installation was performed by The Millgard Corporation in joint venture with the Prime Contractor (MTJD). The selection of specialized drilling equipment and the supervision and performance of the access shaft and riser installations was primarily the responsibility of The Millgard Corporation (TMC).

Jan 1, 2001

By Dan Brown

This paper provides an overview of the advantages and limitations of continuous flight auger (CFA) and drilled displacement (DD) systems compared to other deep foundation systems, along with a summary of important considerations for selection and design. Geotechnical and project considerations are described which favor the use of CFA and DD piling, and also which may be problematic for this type of construction or which may limit the practicality and competitive advantages. A brief summary of design methods for axial and lateral loading is included.

Jan 1, 2005

By Frederick C. Rhyner

The United States government sponsored the construction of a new vehicular bridge over the Diyala River in Bubriz, Iraq. This paper describes the geotechnical engineering for design and construction of drilled shaft foundations for this bridge. An Iraqi geotechnical engineering firm made borings and laboratory tests while analysis and design recommendations were provided in the United States. Despite the severe challenges of engineering in a war zone, excellent cooperation was the key to a successful effort. Three drilled shafts designs were necessary to accommodate the different subsurface conditions: a) medium-compact to compact sands, b) stiff to hard clays and c) mixed soil profile. The alpha and beta methods were used to estimate capacities for a conservative design, recognizing that quality control during construction might be less than what is normally provided in the United States. Iraq has a high seismic risk and LPILE was used to estimate the drilled shaft response during earthquake loading conditions. Settlement estimates were made using FHWA methods. Construction was carried out entirely by local Iraqi firms, despite the challenges of working in an active conflict area.

Jan 1, 2009

By Lok M. Sharma

Development of brownfields is of great interest in these days. Such fields are not easily adaptable for foundations of structures. The uncertainties in ground behavior present challenges of unpredictable subsidence that could be detrimental to the build up facility. A desalination plant had to be located along the seashore, close to the needy population and the existing water supply infrastructure. The available site had been developed as a recreational park area over a dumped construction demolition debris landfill along the coastline. To construct a desalination plant comprised primarily of large concrete basin tanks on slab, founded on the debris fill had its challenges. A ground improvement system in the form of vibro replacement stone columns was designed and constructed. Approximately 5,000 stone columns were installed across the site. This paper describes the analysis process, the design, field load testing, and installation of stone columns. Difficulties during construction and monitoring aspects are briefly described. The plant started operations in the summer of 2008 and to date has performed satisfactorily. When properly designed, the development of brownfields is achievable at other sites.

Jan 1, 2009

By Jim Cook

Arsenal Football Club required the development of a new home stadium in north London, subsequently named the Emirates Stadium. The proposed development comprised a 60,000 seat stadium, with associated facilities and a sports training centre. Described are the foundation solutions and piling construction techniques used, which take into consideration the potential impacts on existing above and below ground railway infrastructure and underground water structures. Methods used by the piling contractor to improve aspects associated with health, safety and quality are also described.

Jan 1, 2008

By Hamed Ardalan, Mohamed Ashour

"CHAPTER 1INTRODUCTIONThe use of piles to stabilize active landslides or to prevent instability in currently stable slopes has become one of the most important innovative slope reinforcement techniques over the last few decades. Piles have been used successfully in many situations in order to stabilize slopes or to improve slope stability, and numerous methods have been developed for the analysis of piled slopes (Ito et al., 1981; Poulos, 1995; Chen and Poulos, 1997; Zeng and Liang, 2002; Won et al., 2005).The piles used in slope stabilization are usually subjected to lateral force through horizontal movements of the surrounding soil; hence they are considered to be passive piles. The interaction behavior between the piles and the soil is a complicated phenomenon due to its 3-dimensional nature and can be influenced by many factors, such as the characteristics of deformation and the strength parameters of both the pile and the soil. The interaction among piles installed in a slope is complex and depends on the pile and soil strength and stiffness properties, the length of the pile that is embedded in unstable (sliding) and stable soil layers, and the center-to-center pile spacing (S) in a row. Furthermore, the earth pressures applied to the piles are highly dependent upon the relative movement of the soil and the piles."

Jan 1, 2013

By James S. Graham

Marine design and construction methods are presented on the caisson foundations for the tower piers at the Brooklyn, Ben Franklin, Delaware Memorial 1st, Tappan Zee, Walt Whitman, Throgs Neck, Verrazano Narrows, Delaware Memorial 2nd, and Newport Bridges. All of the bridges are founded on caissons, bearing on bedrock, soil, or piling. Caissons at the Tappan Zee Bridge are partially supported by piling and partially by buoyant forces. General subsurface conditions for each are provided. The purpose of this paper is inform engineers how bridge foundations using caissons were built over major waterways in the Northeastern USA in the past, anticipating a surge of new bridge construction in the near future.

Jan 1, 2005

By Edwin W. Hickey

This paper briefly discusses the geologic conditions in South Florida relative to the design, construction, and performance of deep foundations. The subsurface conditions in this area are unique in that the rock layers are highly porous and often very soft, and are sandwiched between layers of typically loose, uncemented quartz fine sands. Due to the high porosity of the Miami Limestone, 4-inch diameter rock coring is often required to obtain intact samples, and dewatering of excavations is sometimes difficult or impossible. The sand layers, typically tens of feet thick, are very loose to loose in relative density and have been the cause of unexpected large, deep foundation settlements. The engineering properties of the various geologic formations are discussed, along with typical deep foundation types used in the Miami area prior to and after 1980.

Jan 1, 2003

By Wolfram Groh

New underground floors comprising the complete footprint area of the building structure, were constructed under an existing building in sand, located in the Verdun district of Beirut / Lebanon. The works for the rehabilitation and extension of the Verdun 528 building were carried out between December 1999 and August 2000. A restriction of differential vertical movement of existing load bearing walls and columns had to be respected throughout the construction phase of the new basements. Support measures for the building were taken based on a underpinning system with Bauer SVV preloaded micropiles. The specialty of this underpinning job was that the building loads at the time of preloading and excavation of new basements was substantially less than at final stage. The design of the preloading system was particularly challenging in view of the transition from temporary to final load transfer under variable load conditions. Load transfer was based on the Bauer SVV micropile head system applied in several technical variants. Monitoring of levels of structural elements performed throughout the construction works confirmed that the differential movements of adjacent load bearing columns and walls were maintained within the specified limits.

Jan 1, 2002

By Cau T. Bui

Thanks to Doi-moi (renovation) policy, many great bridges were constructed in Vietnam to meet demands of her booming economy in the recent decade and deep foundation structures were the only alternatives for the foundations of these great bridges. The deep foundation structures were constructed by modern technologies and almost of all these deep foundation structures were designed by foreign companies and carried out by Vietnamese workers and engineers under supervision of foreign experts. Beside successes, there were several failure cases in which the collapse of temporary scaffolding system of Can-tho Cable ? Stayed Bridge due to settlement of its pile foundation killing 54 workers and seriously injuring 80 other workers was the most serious. This paper introduces construction techniques of the deep foundation structures applied to building of great bridges in Vietnam recently. It will especially focus on two failure cases: 1) collapse of temporary scaffolding system of Can-tho Cable ? Stayed Bridge due to settlement of its pile foundation and 2) failure of drilled shaft foundation of Thanh-tri bridge due to poor construction technique and management. These two failure cases were greatly concerned by both bridge specialists and the public. Reasons of and lessons from these two failure cases will be carefully discussed. From the two failure cases, this paper will draw some lessons that should be important issues to be seriously paid attention when designing and constructing deep foundations in Vietnam.

Jan 1, 2008

By J. K. Mitchell

Soil improvement is examined within the context of the characteristics of different soil types, the types of ground improvement techniques that can be used to improve them, and the level of improvements that might be achieved. Several case histories are described to show how the particular soil and foundation characteristics influence the choice and success of different ground improvement techniques. Although the basic methods for soil improvement have been known for many centuries, there have been significant recent advances in the technology for their use. Time effects following the densification of cohesionless soils may lead to significant improvements in strength and stiffness. Unanticipated chemical reactions may follow stabilization using admixtures when soils for which there has been little prior experience are encountered. In some cases foundations that combine features of both ground improvement and deep foundation systems may provide good performance at reasonable cost.

Jan 1, 2010

By Larry D. Olson

Research, hardware development, and field testing have been conducted on systems to allow easy and accurate determination of both foundation tip depth as well as the properties of the soils at and above the foundation tip. The nondestructive testing method used for tip depth determination is the Parallel Seismic (PS) method, while the soil properties are determined by a Cone Penetrometer Test (CPT). The research and development effort reported herein uses a novel combination of the two methods to allow a single piece of portable field equipment to perform both tests. A system has been developed and tested that includes a triaxial geophone and a hydrophone in the cone probe tip to allow collection of the PS data by a CPT rig without requiring a drill rig with hollow stem augers. Using the instrumented tip along with a standard instrumented CPT cone allows for the simultaneous determination of both the depth of unknown foundations and the measurement of soil properties along the length of the unknown foundation. The combined system allows for a more complete and accurate analysis of foundation capacity and scour susceptibility.

Jan 1, 2007

By Douglas L. Scaggs

Driving piles in under water applications has become more common place over the past twenty years. Where only a water depth reachable with a follower or dewatered cofferdam was the rule in the past, newer technologies developed for the offshore oil and gas industry have made depths of even several thousand feet possible offering new possibilities in foundation design and installation. With the new technology, engineers can now more efficiently design structures by placing foundations optimally thereby reducing weight and cost of the overall structure.

Jan 1, 2013

By Robert B. Bittner

The new gated dam on the Monongahela River at Braddock, Pennsylvania, was built for the US Army Corps of Engineers using an innovative ?In-the-Wet? technology. A key feature of this technology involves construction of the foundations through the water and later mating the completed structure or a shell of the structure to the pre-installed foundation. This paper presents a description of the structure, its foundation, construction sequence and design details required to successfully implement this technology.

Jan 1, 2013

By Silas C. Nichols

FHWA Interest is due to: ? An increase in successful projects in the U.S. private sector and in other countries ? Cost effective and more efficient in many circumstances ? Agency Priorities - FHWA "Vital Few" AASHTO TIG

Jan 1, 2005

By J. H. Qian

China is one of the countries with comparatively wide distribution of soft soil. In the wake of the rapid developement in the national economy and construction, the improvement technique of soft soil foundation has been perfected gradually. At the present, an integrated system of soft soil improvement has formed, features of such a system are shown by the variety of improvement methods, the complement of theoretical study to project practice. This paper summarizes mainly the following methods: lime column, vertical drain, vibroflotation and dynamic consolidation.

Jan 1, 2010

By Ignatius P. O. Lam

This paper presents information on design analyses of large diameter piles using conventional p-y curves as recommended by the American Petroleum Institute (API RP2A, 1993). API RP2A adopted the soft clay criterion developed by Matlock (Matlock, 1970) based on 12.75-inch piles. API RP2A also adopted the API sand criteria originally introduced by Reese, Cox, and Koop (Reese et. al., 1974) based on 24-inch piles. Since Matlock and Reese published their original papers, there have been several publications recommending changes to their p-y criteria, especially regarding the need to adjust the Matlock p-y curves for pile diameter effects. The following sections attempt to clarify the issue of diameter effects on p-y curves.

Jan 1, 2013

By Robert B. Bittner

The Sutong Bridge across the lower Yangtze River in China will have, when completed, the longest span (1,088 m) and the highest towers (306 m) of any cable stayed span in the world. The foundations for this record setting span will also be record setting. They are located in water depths exceeding 30 m with maximum flows exceeding 3 m/sec. The soil at the site of the main pylons consists of layers of silty sands and silty clays extending to bed rock at 270 m below river elevation. This paper describes the innovative methods used by the team of foundation designers and constructors to support this record setting bridge at this very challenging site. This paper covers three specific topics related to the foundations of the Sutong Bridge: ? Design and construction of the 131 drilled shaft (2.8/2.5 m diameter and 114/117 m long) under each of the two main pylons, including the post-grouting of all drilled shaft tips. ? Design and construction of the scour protection for the two main pylons, ? Construction methods used to construct the waterline pile caps (113.8 m by 48.1 m by 13.3 m deep) under each pylon.

Jan 1, 2013

By Clifford J. Wren

A geotechnical foundation solution was required to halt and prevent further structural distress suffered by a residential four storey apartment building in Hamilton, Scotland. Residents of the ten year old building started to notice cracking and signs of distress approximately one year after moving into the property. A detailed intrusive inspection of the structure revealed that the building was moving and had suffered significant settlement and structural distress at the shared party wall between it and an adjoining building. Roger Bullivant Limited (RBL) was appointed Principal Contractor to carry out an agreed remedial works contract which included a complete structural ?strip-out? of the ground floor, underpinning, contiguous bored pile retaining wall and reinstatement. The paper describes how a proprietary pile and needle beam underpinning system was used to prevent further differential movement and provide a new secure foundation for the residential building. The case study illustrates how a flexible problem solving approach can be applied to a difficult and sensitive geotechnical project.

Jan 1, 2008