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By David C. Kraft

A major manufacturer and user of machine tools had the need to install a screw press machine at its plant site with the following design load requirements: (1) Vertical Compression Live Load = 2000 kip (8896 kN) and Dead Load = 1000 kip (4448 kN), (2) Rotational Moment = 6600 ft-kip (8950 kN'm). The screw press machine was to be located within an existing manufacturing building. The bottom of the footing base was located 15 ft (4.6 m) below existing floor slab. A geotechnical investigation of the site indicated a 17 ft (5.2 m) thick initial stratum of stiff to very stiff clay underlain by a 14 ft (4.3 m) thick stratum of loose to medium dense sand. Beneath the sand stratum was soft rock described as weathered shale. Obvious concern was raised on the possible effects of the dynamic motion of the screw press and potential resulting settlement within the loose sand stratum. This combination of large loads and dynamic motion resulted in the selection of a helical pile and tieback system to support the concrete foundation. The helical pile foundation system consisted of a group of vertical helical piles installed into the shale rock and a group of inclined helical tiebacks set into the remaining portion of the clay stratum. Four load tests were conducted on the vertical helical piles in order to establish compression load capacity. The results of these load tests as reported herein, led to the addition of a limited number of tubular steel push piles in order to meet the project required Factor of Safety on the design loads. All of the helical piles, push piles and inclined helical tiebacks were successfully installed and the screw press is now installed and operational.

Jan 1, 2003

By Richard Crockford

The World Trade Center (WTC) is located on the west side of Manhattan in New York City, approximately 0.5 miles north of Wall Street, and is owned and operated by the Port Authority of New York and New Jersey (PA). As part of the WTC site redevelopment the New York City Transit Authority?s No. 1 subway line which runs through the site below grade, was underpinned so that the soil beneath it could be removed along with the rest of the new east basement excavation. Consequently a scheme comprising micropile installation through and around the existing subway box was designed. The subway had to remain in use throughout save for planned weekend outages to allow a portion of the underpinning to be fitted through or on to the existing structure. At times this involved accessing and drilling from within the subway tunnel under short General Order (GO) Subway shutdown periods. At either end of the subway passage through the WTC site jet grout underpinning was designed to provide support and to complete the excavation and construction of the east basement wall in the areas beneath the subway where it was impossible to install a slurry wall. The jet grout blocks thus formed had to be largely installed around the clock during 53 hour long GO weekend outages and had to overcome severe logistical constraints in and over the tunnel. The jet grout blocks had to provide strengths of at least 500 psi at 3 days and 700 psi at 28 days. The jet grouted soil mass also had to have a level of permeability less than 0.03 feet/day (1 x 10-7 m/s). After an extensive trial program and then production testing it was concluded that the glacial till above the rock proved to be a particularly difficult soil strata to collect test data from and hence the level of observational monitoring was increased to progress the excavation works. Throughout the installation of micropiles and jet grout columns extensive monitoring was in place and prompted a variety of working method changes. The work described in this paper was performed by the Nicholson Construction Company/EE Cruz Joint Venture.

Jan 1, 2008

By Martin J. Kenwright

Within the famous Harrods department store, a new lift shaft has been constructed, servicing a depth of 22m below ground level as well as the existing 6 storeys of the store. The shaft will connect with a new goods tunnel which is to be excavated beneath the shop, as well as new floor space above ground level which has resulted from the infilling of a previously existing lightwell within the store. The construction of the deep shaft while maintaining uninterrupted use of the store by the Client led to a number of innovative solutions being undertaken. Empirical assessments were made of settlements anticipated from the construction process, which took place within a congested environment of existing foundations. Various elements were designed and installed to mitigate the effects of the inevitable ground movement on the surrounding overlying structure, which supported sensitive high quality finishes and mechanical and electrical installations. The reinforced concrete lining of the shaft was contained within a cofferdam of minipiles. The minipile placement accuracy (1 in 150) was vital as it could not interfere with the subsequent tunnelling works. As the scheme progressed this became even more critical since the minipiles were needed as support for parts of the permanent works. This paper describes:- the high quality placement and control of the minipiled cofferdam, the methods employed in assessing ground movements and the techniques used to mitigate against the effects of these movements.

Jan 1, 2000

By Matthew E. Meyer

Renovation, rehabilitation, restoration and expansion of existing residential, retail, commercial, hospital facilities and historic structures requires assessment and evaluation of foundation systems of various ages. The concept of demolition and reconstruction in urban areas is often more challenging, costly, and even prohibitive in some cases due to historic regulations. The authors have been involved with numerous projects related to existing foundation assessment and retrofit, including: hotel and hospital expansions, historic Art-Deco hotel renovations and expansions, garage structure expansions, additions to prominent auction houses, casinos, printing facilities; high-rise structure foundation retrofitting; forensic evaluations of existing building and highway structure foundation systems, and marine bulkhead sheeting systems. The use of non-destructive testing techniques, high-strain dynamic load testing, full scale pile cap load testing and 3-D laser scanning technology has proved to be vital in the assessment and evaluation process, as well as design of foundation retrofit alternatives. This paper presents various methods and techniques to facilitate a phased approach for optimization of existing foundations and subsequent re-use of foundation systems. These methods and techniques are illustrated through the author?s experience and selected case histories from projects with varied foundation and geologic conditions.

Jan 1, 2011

By A. Frits van Tol, Rodriaan Spruit, Jan H. van Dalen

"Abstract In recent years, there have been major problems with deep excavations in urban areas supported by diaphragm walls. In some cases, like the fatal Nicoll Highway collapse in Singapore the quality of the D-walls was not the cause. However in other projects, like the problems with the major leak in the walls of the Boston Big Dig and with leakage in a few projects in Belgium and The Netherlands was related to poor D-wall quality. Leakage through the D-walls at the joints in deep excavations led in these cases to very serious settlement behind the walls, in the case of the North- South line in Amsterdam, there was severe damage to historical buildings. This paper describes ongoing research that focusses i on acquiring more knowledge on and improvement of D-wall installation, in particular the flow process prior and during casting ii on the detection of anomalies prior to excavation and iii on the composition of the concrete mixture in view of a better and more sustainable concrete quality of D-walls.INTRODUCTIONIn the case of deep excavations in urban areas close to neighbouring buildings, diaphragm walls are one of the best feasible solutions for the retaining structure. Although the costs of D-walls generally exceed the costs of alternative wall solutions, the advantages are decisive in many situations. The main advantages of D-walls are the limited impact of the installation on the built environment, the high stiffness and bearing capacity and the retention of water, even at considerable depths. This makes Dwalls often the preferred solution for deep excavations Sometimes the D-walls are the temporary support while for the final stage a complete concrete box is constructed in the excavation. In many other cases the D-wall has the permanent function of retaining soil as well as groundwater.In the last ten years, there have been major problems with deep excavations in urban areas supported by diaphragm walls. In some cases, like the fatal Nicoll Highway collapse, 2004 , the quality of the Dwalls was not the cause. In other important failures like the collapse of the Archives in Cologne, 2008 and Dubai Infinity Tower Flooding, 2007 a combination of design and quality issues played a role. However, the major leak in the walls of the Boston Big Dig was related to poor D-wall quality (McNichol, 2000). Van Tol et al, (2010) describe a number of case studies in Belgium and the Netherlands, with leakage through the D-walls at stop end joints. In several cases with deep excavations these leakage caused serious surface settlements behind the walls. In the case of the North-South line in Amsterdam, there was severe damage to historical buildings. All these cases have generated considerable additional costs and delays, and subsequently public and political concern. Van Tol et al. (2010) present several possibilities to improve the quality of D-walls.Other disputes related to D-walls deal with the quality of the concrete and the sustainability of D-walls applied as a permanent wall. In particular the porosity of the concrete cover is sometimes problematic."

Jan 1, 2014

By M. J. Preim

Two case histories are presented on the evaluation of static bearing capacity of piles driven in soils that exhibit time dependent strength changes. Under consideration are a steel and a concrete pile driven into soils generally consisting of silty and clayey fine sand. Pile dynamic measurements and analyses were performed on both piles during initial installation, and also during restrike one week later. This information was used to predict each pile's long term capacity (defined as 14 days after initial drive), which was then compared to that measured with a static load test. Agreement between predicted and measured capacities were remarkably good, with an average error of only 4.5 percent. Two weeks after driving, total pile capacities were three times those at the end of drive. If only the skin friction was considered, however, it increased by an average factor of 16. The increase in pile capacity was determined to be linear over the time period considered.

Jan 1, 1989

By Basem Sh. Hazzan

In the last four decades significant effort has been devoted to designing piles in expansive clay soils. Nevertheless, only a scant effort has been devoted to the elimination of heave forces acting on the upper part of lightly loaded piles. For this purpose, an investigation site was established in Karmiel in Northern Israel. On this site sixteen unloaded cast-in-situ piles, both uncoated and coated, were installed in a moderately expansive clay soil in the end of summer 1996. The piles were executed to different depths ranging between 2m and 7m and were observed over a period of 27 months. Another nine unloaded cast-in-situ bored piles were installed at the end of summer 1998 for carrying out pullout tests. These piles were embedded two meters from the ground surface. Results obtained from observations and from full-scale static pull out tests showed that separating the piles from the surrounding clay in the active zone by a twin walled sleeve eliminated the heave forces significantly. The scope of the work is, determining of the elimination degree of the heave forces due to the provision of the above sleeve.

Jan 1, 1999

By Mike Muchard

Augered cast-in-place piles are one of the most cost effective deep foundation options available to designers but have been largely underutilized due to skepticism associated with quality assurance and hence capacity. When installed correctly, unit friction values can rival any other competing foundation system. To this end, many means have been implemented to increase confidence in the competence of the foundation. One such method is load testing via the Statnamic test method. This paper presents an overview of the Statnamic test method, advantages and disadvantages of its use, and several case studies where Statnamic testing of augered cast-in-place piles confirmed quality construction, brought about design changes, or proof tested problematic installations.

Jan 1, 2000

By Klaus Pöllath

The Netherlands RandstadRail project makes use of a large range of sophisticated geotechnical techniques to allow a shield driven tunnel to approach the central station of Rotterdam. This paper describes the construction of three deep excavation pits constructed with 1.2 m and 1.5 m thick diaphragm walls. Besides the presentation of the actual diaphragm wall activities special consideration is given to the break-in and break-out situations of the TBM into the deep excavations pits using sealing blocks and partly glass fibre reinforcement in the diaphragm walls.

Jan 1, 2006

By Bin Zhang

Drilled shafts are a popular type of foundation for transportation applications. They feature the advantages of providing high bearing capacity and generating low construction noise. Advancements in construction technology make it possible to construct drilled shaft with large diameters. In some transportation projects, the full structural loads are carried by a single large diameter drilled shaft; therefore accurately determining the bearing capacity of drilled shafts has important practical and safety implications. The increase of drilled shaft diameter combined with the structure properties of the surrounding soil play in an important role in their bearing capacity. The conventional methods for bearing capacity determination, which mostly come from experience with small diameter drilled shafts, may not work satisfactorily. This paper studies the influence of diameter on the bearing capacity of laterally loaded drilled shafts. Numerical simulations are conducted to investigate the effects of pile diameter on the lateral bearing capacity, especially the influence of shaft diameter and its structural contributions.

Jan 1, 2007

By Maral Papazian Bedian

Construction contracts in the USA contain the clause "Value Engineering" ? an interesting and curious clause allowing contractor initiated design changes. Misleading is the interpretation of value engineering implying cost saving and sharing with the owner, and curious is the timing, just before beginning of actual construction. It is not surprising that such a clause would simply be ignored, because it involves change, often major design changes in very short time; and change is feared, moreover, it is vehemently resisted by all parties, owner, designer, contractor. The problem in the USA may lie in the divergence and separation of the two entities: Designer/Engineer and Builder/Contractor, assigned to the "one" engineering project. The priorities and incentives of these two groups are very different. The Engineer spends years, even decades, in design and prepares contract drawings often without a deep understanding of construction methods. Worse, with all the time available to him and in our era of tremendous advances in computational methods and speed, the designer turns in plans that are inexcusably exaggerated code-based design with excessive safety factors. As to the Contractor, he builds, often without appreciation of design principles or regard for design engineers. Redesign to apply a new technology or optimization of an inferior design just before construction becomes unthinkable. It is not surprising that adverse and hostile relationship between the designer and the contractor is a norm with extended disputes and claims, not to mention the cost these entail. Surprisingly, "Value Engineering" was successfully implemented in record speed on several very large projects in the metropolitan New York area. The process of change was unconventional, painful, and even comical. Four case studies are presented: two Design/Build: the 1.2 billion dollars Hudson-Bergen Light Rail Transit System in New Jersey and the 90 million dollars MTA Bus Depot in Manhattan, and two Conventional Design/Bid/Build: the 90 million dollars Queens Boulevard Bridge and the 150 million dollars Long Island Expressway.

Jan 1, 2002

By Francis D. Leathers

Four friction pile load test programs, including 23 tension tests and 9 compression tests, have been performed as part of the Central Artery/Tunnel Project in Boston, Massachusetts. The tests, performed on both precast, prestressed concrete (PPC) piles and steel piles, yielded the following adhesion values: [Soil Type Clay Clay Glacial Till Interbedded Sand and Clay Interbedded Sand and Clay Pile Type PPC Steel Steel Steel PPC Adhesion (psf) 610 to 1,200 230 to 900 220 to 550 680 1,280 ] The adhesion appears to be affected by differences in pile material type, with PPC piles having higher adhesion than steel piles. However, part of the apparent difference for the clay may be due to differences in time between driving and testing. The significant range of test data means that the need for site specific testing to determine or verify design values of adhesion should be considered during design. Creep rates at loads near failure ranged from about 0.02 to 0.18 inches per log cycle of time, with most values in the range of about 0.04 to 0.08 inches per log cycle of time.

Jan 1, 1994

By J. Moskowitz

Construction of the new JFK International Airport Light Rail System (LRS) began in 1998 with a pre-construction load test program. This $1.2 billion design-build project consists of approximately 13 kilometers of elevated twin rail. The elevated rail system is supported on nearly 500 piers requiring deep foundations. The presence of underlying compressible and liquefiable soils as well as space constraints precluded the use of large spread footings. In the 1980's the Port Authority undertook extensive testing to evaluate various piles and drilled shafts types. The LRS piling sub-contractor and the Geotechnical Engineer conducted additional tests for this project to identify the most cost effective deep foundation type. Candidate piles types included: Monotube®, Tapertube®, and closed ended pipe piles. The tapered pile types were found to be the most cost effective and the project utilized both the Monotube® and Tapertube® piles. This paper presents the results of the load test program and the issues related to pile driving induced vibrations and ground movement.

Jan 1, 2000

By Qi Wang, Zengzhu Kang, Jianguo Liu, Guanglei Liu

"Due to the increase of automotive vehicles, available parking spaces become a new type of limited resource in central cities of China, especially in those old districts without visionary urban planning. Additional mechanical parking in underground space is an efficient solution to provide parking spaces under the situation where the urban space is constrained. Shichahai district is an old protected zone in Beijing which is close to the Forbidden City and there are many Hutong (alleyway) and Quadrangles (courtyard house). No spaces are available for car parking on the ground and all vehicles are parking in Hutong without order currently. The local government plan to do renovation work for this district and improve the residential environment. Several innovative solutions are studied including parking in deep shafts, parking under existing buildings by under-pinned method, parking under buildings by covered excavation method, parking under roads built together with utility tunnel etc. 5000 difference types underground parking spaces are planned to be constructed in the following three years. Project examples are also introduced in this paper. INTRODUCTIONCar parking resources are very limited in central cities, especially in old districts without planning for increasing automotive vehicle volume. Traffic get worse when cars park on the side of the roads or move slowly to find parking spaces. Investigation shows the normal (parking space/ automotive vehicle volume) ratio is about 1.2 in most big cities such as New York, Tokyo and Hong Kong, while this ratio is only 0.5 in Beijing. One solution is to move cars out of central cities. But there are still huge parking requirements for the citizens living in central cities. Shichahai district is an historic protected zone in Beijing which is close to the Forbidden City and there are many Hutong and Quadrangles (refer to Figure 1 for project location). No spaces are available for car parking on ground and all vehicles are parked in Hutong without order currently. The local government had a plan to do renovation work of this district and improve the residence environment. 5000 different types of underground parking spaces are planned to be constructed in the following three years. One project designed and to be constructed by Zhongyan Technology will be introduced in this paper. Other innovative solutions will be introduced briefly as well."

Jan 1, 2017

By Bruno Gemmi

The objective of the ? 200 million ($280 million) project Parma Railways Station-Urban Transformation was the reconnection of the North and South parts of the town by constructing an 80 m (250 ft) wide sunken artery passing under the four double railway tracks of the station without any impact on train traffic. The site of the project, adjacent to the Parma River, presented water seepage problems at any excavation depth. The use of conventional large diameter bored pile machinery was not allowed by the Railway Authority because equipment dimension and construction phases do not comply with train traffic safety regulations. Foundations for the bypass were thus constructed by minipiles nested into jet-grouted soil using machinery operating within the existing head room and at a safe distance from the tracks. Jet-grouting treatment reached depths of 25 to 28 m (80 to 90 ft) from tracks? grade and embedded minipile-heads were terminated at 2 to 3 m (6.6 to 10 ft) below grade. Load tests on minipiles were pushed to failure. Failure occurred at a 240 t (265 t) load without breakage of the bond between the jet grouted soil and the minipiles. A 0.93 MPa (135 psi) shear resistance ??? between minipile steel casing and the jet grouted soil was measured prior to the failure of the steel casings. Overall measured foundation settlements were well within expected values and were considered insignificant.

Jan 1, 2011

By John L. White

Vibratory driver/extractors do more than drive and extract sheet piles. I would say more than sixty percent (60%) of the time, vibratory pile driver/extractors are engaged in work that has nothing to do with sheet piles. This is the main reason I refer to this tool as a "driver/extractor", and omit the word "pile". I have spent the last twenty years applying the technology of the vibratory driver/ extractor to all areas of foundation construction. As you will see, the only limits are humankind's ingenuity.

Jan 1, 1997

By Robert B. Bittner

"AbstractLarge diameter tubular piles offer significant advantages in terms of design performance and economy for major marine structures. This is particularly true for foundations of major overwater bridges in regions of high seismicity such as the west coast of North America. The use of large diameter piles in the range of 2 to 3 m diameter means that fewer piles are required, and the size and mass of the pile caps can be significantly reduced, thereby greatly reducing lateral load demand during seismic events. Another advantage of using larger diameter piles is increased pile stiffness that allows the pile caps to be located at or near the waterline rather than being positioned at or below the mud line. This elevating of the pile cap offers significant cost savings by eliminating the need for deep cofferdams. However, relocation of the pile cap creates new problems and opportunities in regard to the means and methods used to construct the pile cap. With the pile cap at depth, conventional steel sheet pile cofferdams with thick tremie seals are typically used to isolated the cap location and allow dewatering for construction of the cap. However with pile caps positioned up off the bottom, conventional bottom founded cofferdams are no longer cost efficient. Float-in or lift-in cofferdams have been developed to address the need for a more cost efficient method for cap construction. This paper describes the key features of the concept and provides three case history examples of its successful implementation.Pier Construction Using Conventional Sheet-Pile CofferdamsCofferdams are temporary structures used in the construction of bridge piers and other marine structures. Their primary purpose is to hold out water and unstable soil from the construction area, and thereby, allow in-the-dry construction of the permanent structure below the water line and quite often below the mud line. Typically, cofferdams consist of long interlocking steel sheet piles driven through water into the bottom of the waterway. The sheet piles form temporary exterior walls which are typically braced internally with wales and struts. The bottom of the cofferdam is typically sealed with tremie concrete or an impervious clay layer if one exists. The depth at which this type of cofferdam can be used is typically limited by the length of steel sheet pile that can be transported and handled by conventional marine equipment."

Jan 1, 2014

By David Winter

The geotechnical design, construction, and monitoring aspects of a tied back excavation 85 feet deep in Seattle, Washington are presented. The excavation was completed in overconsolidated deposits of sand, silt, and clay. Lateral soil pressures used in shoring wall design were the lowest to date for an excavation of this size in Seattle. Instrumentation data collected from hydraulic load cells and inclinometers were analyzed and are discussed. The data suggest the actual soil pressures felt by the wall were lower than the design values. Recommendations for future study, as well as future design modifications are given.

Jan 1, 1987

By Geoffrey D. Collins

This paper deals with the construction of the Effluent Outfall Diffusers which form part of the outfall for the Deer Island sewage project. The work was executed 15 km out to sea in Massachusetts Bay and required the drilling, installation, grouting and accurate determination of the actual position of 55 riser shafts in 33.5 m deep water. Although not strictly a "foundation", the contractor's approach to the installation of the diffusers was a logical development from many marine foundation projects executed by the Contracting companies over the last decades. The only previous application of this design of outfall had been in Australia where offshore oil drilling techniques had been adapted for use in riser installation.

Jan 1, 1994

By Osama El-Fiky

There are many types of deep foundations currently being used in the San Francisco Bay Area, one of the most common being driven precast, prestressed concrete (PC/PS) piles. PC/PS piles are frequently selected for use due to of ease of installation, availability, and relatively low cost. Disadvantages of using PC/PS piles are noise, vibrations, pollution, front-end delays due to indicator pile programs, and reduced flexibility. An acceptable alternative to driven PC/PS piles was selected for construction of foundations for the heavy housing and administrative buildings at the San Francisco County Jail #3 replacement project in San Bruno, California. The pile type selected, the Auger Pressure Grouted Displacement (APGD) pile, was chosen to reduce noise, vibrations, installation time, and cost, and to allow for greater flexibility of installed pile lengths. This paper presents a case history of the use of APGD piles that were substituted for driven PC/PS concrete piles for the subject project. Standard and quick loading pile load tests were performed to confirm adherence with the design criteria originally used for the driven PC/PS concrete piles. The APGD piles were found to increase shear strength around the piles similarly to driven displacement piles. In addition, this paper presents the methodology used in monitoring APGD pile installation.

Jan 1, 2002