Search Documents

By W. Lum

In the U.S., flexible metal pipe culverts are designed by ring compression theory because the pipes are capable of deflecting and deriving side support from surrounding ground. For economy, tunnel liners are often designed as flexible structures that depend on the lateral pressure of the surrounding ground to maintain stability. In this paper, simple formulas are presented to determine the maximum deflection a concrete tunnel liner may assume and the ring compressive strength of the deflected liner. A tunnel can then be constructed to work within these limits. Similar techniques may be used to design concrete pipes.

Jan 1, 2010

By Yin Zongze

The pile foundation of Sutong bridge pylons is an extra large pile foundation. The length of piles is 115m, and the diameter of the piles is 2.5-2.8m. Since the traditional design method may not determine the settlement and capacity reasonably for such a large pile foundation, the finite element method is used to study stress and deformation of the foundation. The interface element is set to simulate the possible slide between piles and soil layers. The hyperbolic model is taken for soils. Parameters are determined from triaxial test first, and then modified by back analysis on basis of in-situ loading test. The computation results show that the axial force of piles changes with the location of the pile. Outer piles support greater axial force and also friction. The settlement will not be greater than 26cm. The stress and deformation of the pile cap, the abutment, are obtained too. The whole foundation is safe.

Jan 1, 2006

By A. Lyndon

Vertical and lateral load tests were carried out on two 13 m deep bored cast-in-place instrumented piles, socketed into weathered sandstone. The first pile, 1200 mm in diameter, was loaded vertically to a maximum of 16000 kN and then loaded to failure under lateral load (1900 kN). The second pile, 1500 mm in diameter, was tested under lateral load up to a maximum of 2400 kN. It was found that the deflections of the 1200 mm pile were more than twice those of the 1500 mm pile under similar loads. The soils on the site are not easily tested in the laboratory, or by conventional insitu site investigation techniques, parameters needed in design can only be reliably obtained from pile test results. In this report shear moduli are back analysed from the vertical load test and the two lateral load tests. For these similarly installed piles very different design parameters were determined from the lateral load tests, the only known major difference between the piles being that the 1200 mm pile was loaded vertically before it was loaded laterally. Changes in G values needed to match performance under vertical load if applicable to lateral loading could have accounted for a significant amount of the difference.

Jan 1, 1989

By Charles L. Guild

I will add a few facts about the use and development of the Osterberg Test Load Cell and my association with Jorj. I first met Jorj in 1965 when the Guild Construction Co. drove 12" diameter cast-in-place shell piles for him at the Marquette Cement Co. in Nashville, Tennessee. When I met Jorj at the DFI Trustee's meeting in 1985 at Longboat Key, Florida, he showed me a sketch of his idea about using a test cell at the bottom of a caisson to test the end bearing and side friction on a caisson. He had made a successful trial test in Case International's equipment yard and wondered whether a similar device could be made for a driven pile. At first I was skeptical that it could be done but after thinking about it overnight I told him I felt it was feasible and we would do some work on it. At that time, there was a large bridge job going out for bid in Rhode Island using 14" square prestressed concrete piles'. Based on a record of the Guild Construction Co. Inc. driving over 3,000,000 feet of piling on work for the State of R.I., we felt we would have an excellent chance to be allowed to use them so we designed, detailed and fabricated three for 14" square prestressed concrete piles. As things worked out, we did not test them on this job and have not to date.

Jan 1, 1989

By Walter E. Vanderpool

Full scale load tests are frequently performed immediately prior to deep foundation construction to verify the design assumptions. Occasionally, load tests are performed during design development and applied to the final design for critical and non-redundant structures. We believe that full scale load tests can be very valuable and economical for projects, especially in a geologic environment where the record of full scale load testing is very limited or non-existent. The load testing for the Utah Transit Authority?s Airport Light Rail Trax project provides an example of the advantages of a load test in design development. The savings realized by the owner was in excess of $800 thousand dollars.

Jan 1, 2011

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By Wu Jie Mei, Li Yao Liang, Franz-Werner Gerressen, Arthur Bi

Diaphragm walls (D-walls) are known as underground structural elements commonly used for retention systems and permanent foundation elements. In addition, they are also quite often used as deep groundwater barriers, called Cut-Off-Walls (COW). Shanghai ranks third among the most densely populated metropolises in the world. In 1990, only eight million people lived there. Today, Shanghai has about25 million inhabitants. The increasing demand to accommodate the infrastructure of growing megacities like Shanghai pushes the required depth for subway, sewage and foundation projects to the limit. Future projects will demand excavation depths of more than 100 m (328 ft) on a regular basis. Already carried out reference projects will be described and a general outlook for upcoming projects will be given. The paper also explains the installation process in general focusing on the use of trench cutter technology. INTRODUCTION D- walls are known as underground structural elements, commonly used as retention systems for excavation pits and shafts as well as permanent foundation walls or elements. It is anticipated that, with the increasing trend of utilizing more and more underground space to accommodate environmental considerations and urban/suburban development, there will be an increasing requirement for diaphragm wall usage in even more difficult conditions and with increasing depth. The trench cutter is the most important tool for performing this work. The hydraulic grab, a well-known and valuable excavation tool for d-walls reaches its limits in terms of depth and when cutting rock. Therefore the trench cutter technology will be in the focus of this paper. The trench cutter itself is a reverse circulation excavation tool. It consists of a heavy steel frame with two drive gears attached to its bottom end, which rotates in opposite direction around the horizontal axis. Cutter wheels are mounted onto the drive gears. As they rotate, the soil beneath the cutter wheels is continuously broken up, removed, mixed with the bentonite slurry in the trench and moved towards the opening of the suction box of the pump? A centrifugal pump located right above the cutter wheels conveys the slurry via a hose system up to a desanding plant. There the slurry loaded with soil and rock particles is cleaned and returned into the trench.

Jan 1, 2018

By X. L. Huang

This paper deals with the experimental and theoretic study of the contact pressure beneath the deep foundation of Beijing International Hotel, The experiments have been carried out in project and in model footing 6.6m2. The result of measurements shows the contact pressure at the edge is greater than that at the center. The theoretic analysis on the base of elastic theorey is in good agreement with the test if the proposed assumption used.

Jan 1, 2010

By Mark A. Willian

The purpose of this short paper is to present soil profiles and basic soils information for the portion of the I-880 Replacement Project alignment where highway structures are to be built. The information presented here is derived primarily from foundation investigations conducted by the Caltrans Foundation Unit (currently the Structures Foundation Branch, Office of Structural Foundations) and by others under Caltrans direction. The foundation investigation for the I-880 Replacement Project began in May of 1991. The field work was completed in May of 1992 and consisted of 93 rotary sample borings, 11 consolidation sample borings, 6 TEXAM® pressure meter borings, six in-place vane shear borings and 57 electronic cone penetrometer soundings.

Jan 1, 1996

By Mohammed Sakr

A Two-Section Helical Pile (TSHP) is a steel pipe with two shaft sections of different diameters and with one or more helix plates near the bottom of each shaft section. TSHPs are used regularly in western Canada as foundation pockets for single and double circuit distribution power line poles. The results of a comprehensive lateral pile load test program and the field monitoring of TSHPs installed in organic soil (muskeg) over soft clay are presented in this paper. A total of nine full scale lateral load tests were carried out, including seven tests using TSHPs with different diameters and embedment depths, and two tests using one-section helical piles. The prime objective of the study was to evaluate the lateral resistance of TSHPs installed into very soft organic soil (muskeg) overlying soft clay soils, to compare their lateral resistance relative to one-section helical piles and to compare the measured and the estimated lateral resistances using p-y curves. In order to provide sufficient soil data for analysis, the subsurface soil stratification was evaluated using two different techniques including; Cone Penetration Tests (CPT) and Portable Soil Probe Tests (PSPT). The two testing techniques were also compared and evaluated. This paper summarizes subsurface soil conditions, pile configuration, helical pile installation procedure, testing setup and results.

Jan 1, 2009

By Maria Flessas, Justin Ray, Danielle Steinmetz, Brian Zuckerman

"The Ventura County Medical Center Hospital Replacement Wing project consists of the construction of a 2- to 3-story building with a basement encompassing the entire footprint and two corridors connecting the new hospital wing to existing buildings. The site is located in the Ventura Basin where strong ground shaking has been observed during moderate to large earthquakes on nearby faults. The upper 90 feet of the soil consists of loose to medium dense finegrained sands and low plasticity silts that are potentially susceptible to liquefaction, seismic densification, and hydroconsolidation. Ground settlement associated with a large seismic event on a nearby fault is estimated at 20 to 26 inches. To account for the anticipated ground settlement, auger pressure grouted (APG) piles gaining support below the potentially liquefiable soil were selected for the support of the proposed structure. Challenges for pile design included the anticipated earthquake-induced ground settlement, high downdrag loads, low soil lateral capacity during strong ground shaking, and the effect of pile installation on the performance of the existing adjacent buildings and the installed shoring system. The replacement hospital is supported on over 600 APG piles, with lengths varying between 120 and 140 feet. Axial pile capacities were verified with an extensive indicator pile installation program and dynamic pile load testing.INTRODUCTIONThe Hospital Replacement Wing (HRW) project is at the Ventura County Medical Center (VCMC) in Ventura County, Southern California (Figure 1). The VCMC consists of three interconnected hospital buildings (Buildings 303, 304, and Fainer Building), the Medical Laboratory/Cafeteria Building, two mental health buildings, a medical office building, an emergency generator building, and surface parking lots. The HRW is near the center of the campus, adjacent to several existing buildings.The HRW is a 2- to 3-story structure, with a 15- to 20-foot-deep basement beneath the entire 95,000-square-foot building footprint. The HRW project includes a Loading Dock, a four-level corridor to the Fainer Building (Fainer connector), and a two-level corridor to the Medical Laboratory/Cafeteria Building (Café connector). The corridors are structurally separated from the existing buildings. Typical dead plus live load column loads for the HRW range from about 635 kips to 935 kips and total loads range from about 860 kips to 1,295 kips."

Jan 1, 2016

By Vincent Joannes, Marine Lasne, Luca Brenelli, Colin Serridge, Inge van Baardwijk, Martin Stanley, Anthony Fisher, Mary Ellen Bruce, Tony Suckling, Pedro Avellanosa

"Abstract The European Federation of Foundation Contractors (EFFC) and Deep Foundations Institute (DFI) developed a sector-specific carbon accounting methodology and associated “carbon calculator” for foundations and geotechnical works. The EFFC-DFI Carbon Calculator is believed to be one of the construction industry’s first collaboratively produced carbon calculator tools for European and international countries based on verifiable and standardized data. It is intended that the tool be adopted internationally and become the open-source industry standard for ground works. A detailed methodological guide is provided with the calculator (Lemaignan and Wilmotte, 2013). This guide explains the background of the standards, accounting methodologies, emission sources and factors that were used as the bases for the tool development and includes detailed guidance on use of the calculator.Drivers for DevelopmentFoundation contractors anticipate project cost and carbon emissions will become inextricably linked in response to the climbing price of fossil fuels and carbon intensive materials as resources become scarce. Low carbon solutions will therefore become more competitive options. Also with high profile construction projects having low carbon/carbon neutrality as requirements, sustainability in the foundations industry also becomes a market issue.This carbon calculator will be used to lead the industry and shape the expectations of commissioning organisations by providing insight into the carbon cost of their projects. Commissioning organizations are encouraged to be aware of the carbon impact of projects and to also facilitate a fair and accurate way of comparing footprints to provide a level playing field for foundation contractors."

Jan 1, 2014

By E. Stoetzer

In all known deep mixing processes the existing soil is mixed with self hardening slurry by mixing tools that rotate about a vertical axis (augers, mixing paddles). Wall panels are constructed using sets of multiple mixing tools combined into a single unit. These techniques have been developed on the principle of the rotary drilling technology. In contrast, the new Cutter Soil Mixing or CSM technique is derived from the cutter technology. The soil is loosened and broken down by cutter wheels, then mixed in-situ by the rotating cutter wheels with the self-hardening slurry - introduced into the ground between the two wheels - to form a soil-slurry mortar. The main area of application lies in the construction of cut-off and retaining walls.

Jan 1, 2006

By Paul W. Mayne

Axial pile performance can be rationally evaluated within an elastic continuum framework using field results from seismic piezocone tests (SCPTu). Adopting a versatile Randolph-type elastic pile model, the approach can be applied to either traditional top down loading using an anchored reaction beam or the newer Osterberg cell that simultaneously pushes the base and shaft in opposite directions. The axial load distribution within the shaft is also evaluated. For site-specific data at a given site, the SCPTu is an optimal means for collection of subsurface information because it combines penetrometer readings and downhole geophysics in one sounding. The results obtained are at opposite ends of the stress-strain-strength curves, specifically the peak strength for capacity interpretations and the small-strain stiffness (Emax) for evaluating the initial deformations. Axial pile capacity can be analyzed using both direct and indirect CPT methods. As such, the approach allows for a complete representation of the axial load-displacement-capacity curve for pile response. Case studies are presented for deep foundations situated in stiff clays at two national geotechnical test sites located in Houston and College Station, Texas, using top down loading, as well as a third case study of a drilled shaft in clay till loaded by O-cell in Alberta.

Jan 1, 2009

By Donald J. Murphy

Longevity of structural units, as compared to the planned useful life of a facility, always is a design consideration. Typical concerns include slow decay due to environmental factors, and changes in constitutive relationships governing the performance of the material involved. With respect to foundations, the usual items of interest are corrosion of steel and concrete, and time dependent behavior of the soil/structure system. For piles, as with other foundations, deterioration is precluded, mitigated or otherwise accounted for by assessing properly the ambient situation (sulphates, pH, stray currents, resistivity) and providing safeguards, such as resistant construction products, oversizing, coatings, and/or cathodic protection. On the other hand, long term performance of the pile foundations, as affected by time dependent characteristics of the supporting soil or rock, can be predicted and controlled only with a synergetic coupling of analyses and field tests. The history of a project for which this approach was followed forms the basis for this paper.

Jan 1, 1986

By Patrick E. Durnal

A joint venture of Ben C. Gerwick Inc., Sverdrup (now Jacobs) and DMJM (now DMJM Harris) designed the $779 mill seismic upgrade of the Richmond - San Rafael Bridge over the San Pablo Bay in the San Francisco Bay Area and provided construction support to Caltrans. Construction of the marine foundation retrofit was completed by a joint venture of Tudor Saliba/Tidewater/Koch-Skanska and their subcontractors: Pomeroy Precast Construction, AGRA Foundations, Dutra Construction and Vortex Divers. Construction management and inspection was performed by Caltrans with support of various consultants.

Jan 1, 2013

By B. B. Broms

A method for calculating the bending moment induced in misaligned or bent piles is described, The maximum bending moment varies with the angular rotation between the pile segments, the coefficient of horizontal subgrade reaction of the soil and the flexural rigidity of the piles. A case history involving damages to misaligned 365 x 365 mm square precast concrete piles is described.

Jan 1, 2010

By Ryan Higbie, King Chin, Matthew Anderson, Mike Huggins, Rian Johnson, Dave Sinsheimer

"The Permanent Canal Closures and Pumps (PCCP) project is the capstone piece of New Orleans’ extensive hurricane risk-reduction system constructed following Hurricane Katrina. The project consists of three discrete pump stations and flood gates on the shore of Lake Pontchartrain which provide a storm surge barrier and pump rainwater from the City of New Orleans’ primary drainage canals. The depth of the pump station structures ranged between 39 and 45 feet below sea-level. USACE developed the PCCP project for design-build delivery; granting the project team latitude to develop innovative, cost effective solutions for the project. The use of OPEN CELLTM cofferdams to construct the pump station structures was one such innovation. OPEN CELL structures utilize the strength of the retained soil to anchor cellular sheet pile face arcs; allowing a free-field of construction within the cofferdam. This cofferdam design did not require ground improvement or dewatering around the perimeter of the cofferdam. The free-field cofferdams streamlined construction and large equipment installation within the structures with no encumbrance from internal bracing. Meticulous force-based design, soil-structure numerical modeling, and physical testing were all techniques used to present and gain USACE acceptance of the design on this vital element of the work.PROJECT DESCRIPTIONThe Permanent Canal Closures and Pumps (PCCP) project is the capstone piece of the City of New Orleans’ extensive hurricane risk-reductions system constructed following Hurricane Katrina in 2005. The project encompasses three separate pump stations and floodgate structures located at the mouths of three outfall canals (17th Street, Orleans, and London) on the south shore of Lake Pontchartrain. These three canals, running from the south to north, act as the primary conduits for discharging water from the New Orleans area. Prior to Hurricane Katrina, these canals were operated with pump stations two to three miles upstream of the mouths at Lake Pontchartrain. This left long stretches of levee on each side of the canals exposed to storm surges entering from the lake. Three levee failures occurred along these canals during Katrina; two at London Canal and one at 17th Street Canal. The failures resulted in major flooding of the surrounding neighborhoods, significant damages, and loss of life.Following initial canal levee repairs after Hurricane Katrina, USACE, in partnership with the Louisiana Coastal Protection and Restoration Authority (CPRA), took action to move the line of flood protection to the mouths of these three canals at the edge of the lake. By cutting off the storm surges from Lake Pontchartrain at the entrance to the canal, over ten miles of canal levee would no longer be exposed to storm surge water elevations, significantly decreasing the risk of failure."

Jan 1, 2017

By T. Iwanowski

Stress wave measurements and calculations are often used to make a safe determination of the bearing capacity and the integrity of driven piles. Some applications to the restoration of old buildings in the Old Town of Stockholm are referred to and especially analyses of measurements combined with simulations are discussed here.

Jan 1, 1991

By James Green

It has often been said that the best contracts written are by people who are suspicious of each other. The Spanish philosopher, Ortega y Gasset, said: "Every contract is an Act of Distrust." The arena for dispute settlement outside of the courts is increasing day by day - contracts, especially construction and civil engineering contracts, are written containing arbitration clauses for settling disputes - the very drafting of standard forms of contract, do in some instances by their very construction, create an ambiguity as to intent and provide a breeding ground for dispute. I come from a land far across the sea - the most southern land before the South Pole. Being a young country, 150 years old, we are still progressing - being far removed from the trouble free zones of the world and nuclear free we enjoy a lifestyle second to none.

Jan 1, 1987