Search Documents

By Grant R. J. Bearss

Due to environmental concerns in urban construction, many typically simple projects become very complex or feasibly impossible. The introduction of relatively new concepts has redefined "impossible", again simplifying these projects and making them "possible". Case Study One covers the use of Pressed-in Tubular Piles on portions of the Long Island Expressway in Queens, New York. Innovations in the design, material and installation method solved many typically inherent problems on projects of this type and resulted in cantilevered walls that supported a 35ft (10.668m) excavation. Design predictions and actual measured deflections of this wall were within millimeters. Case Study Two covers the use of Pressed-in Tubular Piles on portions of the Hodogaya Bypass in Yokohama, Japan. Innovations in equipment development allowed for a cantilevered retaining wall to be constructed without affecting the adjacent right-of-way, dramatic reduction of the overall construction duration and installation of tubular piles in soils with SPT N values greater than 160.

Jan 1, 2002

By Ahmad F. Souri, Murad Abu-Farsakh

"In this study, the static lateral resistance of vertical and battered pile groups was analyzed using 3D finite element analysis. The battered pile group finite element model was verified using the results from a case study performed on the M19 pier foundation of the I-10 twin span bridge in Louisiana. The vertical pile group model was created by adjusting pile inclinations of the verified battered pile group model. The finite element models utilized nonlinear constitutive models for materials behavior and a soil-pile interface model. The results showed that the battered pile group had greater lateral resistance than the vertical pile group with 60-70% lower pile cap displacement. The largest lateral load share was found in the middle rows in the battered pile group, while it was in the leading row for the vertical. The soil resistance profiles showed that the vertical pile group mobilized greater soil resistance compared to the battered pile group.INTRODUCTIONThe lateral resistance of a pile-soil system depends on both pile stiffness and soil reaction. The soil reaction is a nonlinear function of deflection, depth, pile stiffness, and soil stiffness and strength. The lateral capacity of single piles is evaluated at the maximum deflection limit, and can be predicted using established methods such as the p-y curve method (e.g., Matlock 1970, Reese et al. 1974), elastic solution by Poulos and Davis (1980), the strain wedge model (Ashour et al. 2004), and the finite element method (e.g., Yang and Jeremic 2002, Comodromos and Pitilakis 2005, Isenhower et al. 2014). For pile groups, the lateral capacity of a pile-in-group is less than the isolated single pile case because the soil in front of the pile-in-group is weakened by the overlap of stress zones from surrounding piles. The latter is referred to as the shadowing or group effect (Fig. 1). Prediction of the lateral capacity for pile groups is based on the p-y curve method for single piles with the use of empirical factors called “p-multipliers”. The p-multipliers accounts for the shadowing effect, and are a function of pile-pile spacing and soil type (e.g., Brown et al. 1987, 1988, McVay et al. 1995). Moreover, the lateral capacity of pile groups is also influenced by vertical load, piles arrangement, and slenderness ratio (e.g., Rao et al. 1998, Patra and Pise 2001, Ilyas et al. 2004, Hussien et al. 2012).Battered piles refer to piles installed at an angle with respect to the vertical to increase their lateral capacity. The greater lateral resistance is achieved by the additional axial reaction in the pile. Battered piles are called “negative battered” when inclined in the load direction, and “positive battered” when inclined opposite to the load direction (Fig. 1). Previous studies concluded that the lateral resistance is highest in positive battered piles followed by negative battered and vertical piles, respectively (Murthy 1964, Meyerhof and Yalcin 1993, Zhang et al. 1999)."

Jan 1, 2017

By Mauricio Terceros, Martin Achmus, Freddy Lopez

The massive use of deep foundations had a remarkable influence in the building industry in the 20th century. Piles and micropiles made possible to erect thousands of civil structures around the world, changing quintessentially the urban and rural landscapes. Especially in urban areas, the ongoing development requires not only new infrastructure, but also to increase the capacity and/or to extend the serviceability of existing structures (buildings, bridges, etc.). Factors such as the change of use of existing facilities or the requirement to comply with updated building regulations confront Civil Engineers with the question, whether to tear down and build new structures, or to reinforce the existing structures from their foundations. Micropiling has enabled designers to come up with technical feasible solutions to retrofit the existing deep foundations, making the structural reinforcement a real option, even under considerable changes in the loading conditions. The following article presents an overview of an intervention project, where micropiles were designed to reinforce the original pile foundation of an existing building, enabling it to be reused with a different structural function. This paper will focus mainly on the analysis of the interaction between the existing piles and the reinforcing micropiles, especially in terms of settlements’ compatibility. Finally, the adopted solution, with its correspondent design considerations and execution process will be presented.

Jan 1, 2018

By Takefumi Takuma, Masashi Nagano, Christopher DellAringa

Multiple agencies in Southern California are retrofitting and upgrading their levees to catch up with ever-advancing urbanization affecting the requirements for existing channels and levees in this seismically active zone. Pressed-in sheet piles have been specified on some of these projects to minimize noise and vibration problems associated with sheet pile installation. This paper will study three Southern California levee and sewer pipeline retrofit projects that utilized pressed-in sheet piles in hard soil conditions with N-values higher than 50. BACKGROUND Southern California is home to numerous drainage channels fortified with earthen levees. In spite of the region’s semi-arid climate with varying annual precipitation from year to year, winter storms can bring in heavy and continuous rainfall to the area which overwhelms the levees’ capacities at times. Some levees are running through densely populated areas with homes and other sensitive structures such as underground utilities and bridge piers. Conventional sheet pile driving utilizes either percussive or vibratory pile driving methods, both of which generate high levels of noise and vibration, causing nuisance and potential damage to nearby structures. On the other hand, the press-in piling method utilizes a hydraulic force to push piles into the ground, thus practically eliminating the noise and vibration issue. Although there are types of press-in piling systems mounted on tall leaders on large crawler-base machines, they are less frequently used due to its much larger size and more limited drivability than the type discussed hereunder. The other type of press-in machine sits on top of already installed piles and is anchored with its own weight and additional counter weight when starting off as shown in Figure 1. Once the first few piles are pressed in, the equipment grips on top of the installed piles and moves forward on its own as the pile installation progresses. See Figure 2. This method does not use a vibratory or percussive force to install piles.

Jan 1, 2018

By Matthias Pulsfort, Markus Herten, Rolf Breitenbücher, Claudia Fierenkothen

"Secant bored pile walls are frequently used as retaining walls in watertight excavations to cut off ground water aquifers and are subsequently exposed to ground water pressure loading in addition to earth pressure loads. To avoid extra loading from ground water pressure in soils with limited permeability, it can be useful to arrange drainage windows within secant bored pile walls by means of single primary piles filled with porous concrete without reinforcement cages, which usually have to be placed within casings in submerged conditions. This concrete may serve as a horizontal arch between the reinforced secondary piles, but it must however enable vertical draining between load carrying construction beams and the bottom of the excavated pit. In the present submission, the results of several material tests with different mix designs of porous concrete with certain admixtures are presented together with first and important experiences with a wellsuited placement technique for porous concrete casings in small- and large-scale laboratory tests. It can be shown that the usual placement technique of employing a tremie pipe is not suited for this type of unsaturated concrete. Instead, pouring with a particular kind of cone and an open conductor pipe has proven successful.Additionally, special testing methods are currently developed for judging the suitability of the desired concrete mix design in preparation for an upcoming real-scale experimental pile installation in Germany.1. INTRODUCTIONRetaining walls are often built as secant bored pile walls in order to cut off aquifers saturated with groundwater against deep building pits. In soil types with relatively low permeability, however, seepage flow may be permitted, because the quantity of groundwater to be pumped is limited, and the range of influence due to dewatering is not reaching far. Thus, the hydrostatic water pressure on the retaining wall can be considerably reduced, leading to a more economic design (see Fig. 1).In unsaturated soils, the dewatering effect can be achieved by means of porous pervious concrete with a uniform grainsize distribution of aggregates typically placed in a borehole under dry conditions. With regard to the use of porous concrete to be placed at the ground surface in road pavement applications, experience is sufficiently available as shown, for instance, by Neithalath et el. (2010). However placing the porous concrete in a bored pile using a tremie pipe under submerged conditions is a challenge and a completely new approach, because there is a considerable risk of segregation of the fresh concrete, separating the cement lime paste from the aggregates when in contact with water and leaving only neat gravel on the one hand as well as a tight cemented area at the bottom of the pile on the other hand. If this concrete placement is successful, additional dewatering by means of extra wells behind the retaining wall can be avoided. Of course the seepage flow in the adjacent soil needs to be regarded seriously."

Jan 1, 2017

By Priyadharshini M. R., Premalatha K

"Abstract With the development in the construction of heavily loaded structures, the necessity of pile foundations has increased. For the transfer of heavy loads, it is mandatory that the piles need to be socketed in the underlying rock strata. The load transfer in bored rock socketed piles is by end resistance or the combination of shaft and end resistance which in turn depends on the length of the rock socket. The determination of socketing length of the pile at present is mostly based on a few factors which affect the pile load transfer mechanism. The effect of all the possible factors involved, need to be studied in proposing guidelines for the design of rock socketing length of the pile. Analyses are carried out using finite element analysis software (PLAXIS 3D Foundation) to understand the influence of the thickness of overlying strata for different socket lengths of piles in weak rock. From the load settlement curves, the influence of the overlying soil on the rock socket length isobserved and an effective rock socket length is proposed.IntroductionThe determination of socketing length of the pile at present is mostly based on a few factors affecting the pile load transfer mechanism, which sometimes give a better design and sometimes an uneconomical design. Too much socketing length results in more construction time and higher costs. Therefore, the effect of all possible factors involved need to be studied in proposing guidelinesfor the design of t h e r o c k socket length of the pile.The factors that affect the termination criteria of the rock socketed pile are the capacity requirement, thickness and properties of the overlying soil, characteristics of the founding strata, drilling tools used, roughness of the rock socket and nature of loading.A comprehensive study was performed to understand all the above mentioned factors in different types of rocks. In this paper discussion is made on the settlement results, specifically the influence of overlying sand of different densities above a weak rock. The influence of stress developed is not discussed, keeping in mind the size of the paper under study."

Jan 1, 2014

By Steve Thoman

After the 1989 Loma Prieta Earthquake, the California Department of Transportation (Caltrans) initiated an overview of the Caltrans Bridge Design Specifications (BDS) and bridge seismic design practice in California. This overview is continuing under the direction of the Applied Technologies Council (ATC-32), to review and revise as necessary existing standards, performance criteria, specifications, and practices for design and construction of new bridge structures within California. The ATC-32 project began in August 1991 and is expected to be completed in 1995. Since 1990, Caltrans project-specific seismic criteria have been developed and implemented on the I-280 and I-480 projects in San Francisco. Caltrans and an independent seismic safety review panel continue to develop and implement these criteria on other projects. In 1991 and 1992, project-specific seismic criteria were used on the I-880 reconstruction project in Oakland. The seismic safety review panel considered the I-880 seismic design criteria a state-of-the-art methodology to ensure seismic safety against collapse of bridge structures subjected to a maximum credible seismic event. This paper highlights the 1992 "I-880 Reconstruction Project Seismic Design Criteria Review" report prepared by the Seismic Safety Review Panel and Caltrans Division of Structures and will compare pre-1989 BDS and AASHTO methodologies to the I-880 criteria.

Jan 1, 1996

By H. L. Jessberger

In recent years piled raft foundations of multi-storey buildings on weak soils have generated much interest and discussion. By taking account of the effects of each component of the system - the pile group and the raft - it is possible to reduce the settlements and inclinations of the system and to have an expedient load distribution on the piles and the raft. Thus the structural design of the foundation can be optimised.

Jan 1, 1991

By Eric S. White, Thomas J. Sabourin, Khuram R. Mohib

"This paper presents the challenges associated with the design and construction of a steel sheet pile cofferdam supported with one level of grouted anchors in clean to silty sand with gravel. The initial assessment of the subsurface conditions indicated loose to medium dense soil with intermittent dense to very dense layers with no occurrence of cobbles and boulders. Sheet piles were proposed to be installed to a depth of 24 m below the ground surface to limit dewatering requirements for the cofferdam. During sheet pile installation, refusal of piles occurred at multiple locations forming passages for increased flow into the cofferdam. Modifications were made in the design of the dewatering system as a result of the increased flow. Finite element modeling was used to select the necessary modifications to the dewatering system within the cofferdam. Wells were installed based on the findings of the numerical model. Model simulations showed good comparison with monitoring of the field installed dewatering system.INTRODUCTIONIt is necessary to consider the impact of the ground water, subsurface stratigraphy, strength, and drainage behavior of the soil for the design and construction of cofferdams. This paper presents a case history of the construction of a cofferdam in Northern Ontario, Canada. The project consists of the construction of a powerhouse, intake, and tailrace which will generate around 28 MW of renewable clean energy by diverting water from New Post Creek through a power house and discharge into the Abitibi River. The focus of this paper is the dewatering and excavation support required to permit construction of the powerhouse. The layout of the cofferdam is shown in Fig. 1. The cofferdam for the powerhouse is rectangular in shape with sheet piles on all four sides intended to be driven to the design toe El. 101 m. The east and west walls have a length of 46.3 m. North and south sides are 47.6 m long; and in addition, two cantilever sheet pile walls bound the tailrace on the west side and two cantilever walls were installed on the east for construction of the penstock inlet. The ground surface in the powerhouse cofferdam area, before commencement of sheet pile driving, was brought to El. 125; the ground then slopes up to the East, toward New Post Creek, and the site is bounded on the West by the Abitibi River. 186 pairs of sheet piles were used to create the cofferdam and cantilever walls. The deepest excavation is to elevation 114.4 m. Within the west half of the cofferdam footprint, the base of excavation slopes upward at 3H: 1V to facilitate the tailrace discharge into Abitibi River.SOIL STRATIGRAPHYThe cofferdam design was based on the geotechnical investigation conducted by AECOM (2014) which included two relevant boreholes near the powerhouse footprint. The ground elevation at the time of investigation varied between 131 to 129 m. The material observed to the full depth of investigation was comprised generally of coarse to fine sand and gravelly sand or a sand matrix with gravelly inclusions. Some intermittent layers of clay and silt intrusions were also observed. Generally the soils grade finer away from the river. SPT N60 values were recorded in two borings during the field investigation with values reported from 3 to 92. The in-situ conditions ranged from compact to dense with some loose and some very dense zones. Figure 2 shows the variation in SPT N60 values with elevation."

Jan 1, 2017

By Walter Ensinger

Special foundation works is one of the most innovative sectors in civil engineering and construction. Both engineering techniques and construction machinery are undergoing continu­ous further development. These developments are providing ways to meeting the world-wide requirement for special geotechnical works even faster, even better and more efficiently. Unfortunately, accident prevention organisations have had to realise that the figures on in­dustrial accidents in special foundation works are still above average in number. The Safety & Environmental Working Group of the EFFC thereupon started to carry out a survey on acci­dents occurring in this sector and used this information as a basis for the preparation of acci­dent statistics and an accident analysis. The objective of this undertaking is to determine key accident occurrences and their causes and to consequently determine measures for improved health and industrial safety.

Jan 1, 2002

By Jesús E. Gómez

In the Summer of 2011, emergency repairs to the Jefferson Memorial North Plaza and Seawall were completed. These repairs were necessitated by settlement and lateral movement of the seawall and North Plaza which prompted the National Park Service (NPS) to initiate an investigation as to the possible causes of the movement, and commission a design for its mitigation. Information gathered from extensive instrumentation on site led to the design of a movement mitigation scheme that included demolition of the Ashlar Seawall and reconstruction of a new seawall. The new seawall foundation is an A-Wall consisting of vertical caissons and battered pipe piles connected to the seawall itself. The scheme provides resistance to future vertical and lateral movement of the North Plaza and the new seawall. Repair to the seawall and plaza began in December 2009, and was completed in August 2011. This paper discusses the mechanisms believed to be responsible for settlement and lateral movement, summarizes the procedure followed for design of the mitigation, and describes the construction methods and some challenges faced during the repair.

Jan 1, 2011

By Jeffrey R. Hill

To extend the life of the Merchants Railroad Bridge crossing the Mississippi River in St. Louis, MO, the owner implemented a rehabilitation and reconstruction project. The Merchants Bridge provides a key link in the transcontinental railroad system. The bridge is of local importance to the Terminal Railroad Association ? providing a link between St Louis and a rail switching yard in Venice, IL. The intent of the bridge rehabilitation is to keep the Merchants Bridge in service, even though the bridge was originally constructed in the 1890?s. The project involved replacing the East and West approach deck truss spans with new deck girder spans. The rehabilitation program required construction of new concrete piers to support the new spans. In order to reduce the track down time to two, ten day single track shutdowns, the specifications required that all foundation and substructure work be completed while leaving the existing spans in place. The preliminary bridge design specified rock-socketed drilled shaft foundations. Drilled shafts proved to be challenging due to working from beneath the existing bridge, a high water table, utilities, a flood wall, and existing rail way lines. The micropile alternative was technically appropriate given the access limitations, shortened the foundation rehabilitation schedule by several weeks, and realized a significant cost savings to the Owner.

Jan 1, 2006

By C. Van der Veen

The use of the quasi static (Dutch) Cone Penetration Test (CPT) is described as a tool to predetermine the ultimate bearing capacity of the pile point. An analysis is given why a purely theoritical approach does not meet with success. A practical method is explained of extrapolating the cone resistance to predict the pile point resistance. The method has been calibrated against the result of 32 selected high standard loading tests on pile points in the Netherlands.

Jan 1, 1989

By Ali Ameli

Design loads are limited for piles relying upon toe stresses in rock due to uncertainty about the rock quality over the whole pile diameter because of rock mass properties or construction effects. The paper discusses the use of video images to evaluate rock quality at the bottom of piles socketed into graniodorite bedrock in a steel pipe pile project. Skillful interpretation was required to assess the 3D properties of the rock from video images. It is necessary to observe the rock mass characteristics near the project site for better perception of the rock features from the images. Video image interpretation skills were established by the evaluation of the cores drilled under the socket base and the results of pile loading tests. Correlations were found between rock appearance in the images and the rock socket drilling records. Rock socket acceptance criteria were developed through monitoring the drilling operations for the specific site procedures. Video images then served as one of the quality-assurance tools together with probing and pile loading test. Lessons and methods learned from video inspection in this project could be used to evaluate rock quality in similar cases.

Jan 1, 2006

By Kirk A. Mcintosh

Augered, cast-in-place (ACIP) piles have been utilized in the United States for a wide range of projects since the 1950's. Due to the cast-in-place nature of the installation method (and lack of a driving criteria); however, ACIP piles have not been readily accepted by some practicing geotechnical and structural engineers. Since ACIP piles were initially developed, the installation equipment and techniques have been improved and refined and the number of experienced contractors has significantly increased. Over the past 10 to 15 years, the pile type has experienced significant growth in the United States (particularly in Florida) because engineers have become more knowledgeable and comfortable with its use. The Miami area, in particular, has experienced considerable growth in the utilization of ACIP piles primarily due to their usage on the $1 billion Miami Metrorail System project in the early 1980s. The economic advantages over other deep foundation types, coupled with some unique installation advantages, have shown that ACIP piles can be a viable foundation alternative on many projects. Even though ACIP piles have gained respect in the private sector, the pile type has generally not been readily accepted by government transportation agencies. The reluctance to readily accept this foundation type stems primarily from the quality assurance aspect of cast-in-place pile construction. Additionally, there has not been much research activity on this foundation type, technical papers, formal associations (other than the DFI), or a concerted effort to standardize the industry. This paper serves to discuss the state of practice for ACIP pile installation in the state of Florida.

Jan 1, 1997

By Lori A. Simpson

Mission Bay is a 300-acre reclaimed site in San Francisco, California, that is currently being redeveloped. Plans include new neighborhoods, parks, a new University of California, San Francisco, research and development campus, a biotechnology campus, and commercial office buildings. New infrastructure is being constructed throughout the site, consisting of utilities, pump stations, and roadways. Previously, Mission Bay was a part of the San Francisco Bay. Reclamation of the shallow bay coincided with the booming development in San Francisco in the 1880s and continued through 1920. Subsurface conditions are extremely variable throughout the site. The stratigraphy generally consists of 5 to 45 feet of fill, up to 140 feet of weak, compressible clay (?Bay Mud?), dense sand, stiff clay, and bedrock of the Franciscan Complex that has been encountered 5 to 210 feet below the ground surface (bgs). Geotechnical issues related to these subsurface conditions include liquefaction, lateral spreading, settlement, and adequate foundation support. This paper presents case studies of the geotechnical aspects of design and construction of several buildings in Mission Bay, highlighting the similarities and variability in the subsurface conditions and the different conclusions and solutions developed for each project. The case studies will include: 1) a building supported on steel H-piles where the depth to bearing varies from about 70 feet bgs in one half of the site to 165 feet bgs in the other half; 2) a building supported on precast, prestressed, concrete piles bearing in a thick, very dense sand layer; 3) a building with over 100 feet of Bay Mud supported on 120- to 180-foot-long PCPS concrete piles driven to bedrock adjacent to buildings supported on steel H-piles driven to bedrock; and 4) sites where auger pressure grouted displacement piles (APGD) and Tubex piles were installed. Case studies will include results of pile driving analyzer (PDA) testing and static pile loads tests, where performed.

Jan 1, 2006

By J. -M. Rescoussier

Due to Important settlements inducing major structural damages, the western part of the Grand Littoral shopping centre has been closed in 1997. The present paper describes the project of underpinning including not only micropiles under the structure of the building but also a reinforcement of the soil located between the shopping centre and the edge of the embankment surrounding the western part of the shopping centre. The aim of this reinforcement is to reduce existing horizontal movements to allowable values.

Jan 1, 2002

? Hollow Stem Auger ? Drill Bits ? Leads/Torque Arm ? Hydraulic Gearbox ? Hydraulic Power Unit ? Grout Pump ? Crawler Crane

Jan 1, 2003

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 A. Holeyman

The displacement compaction piles described in the paper are installed using a heavy casing or tube and an internal drop hammer. The casing which initially is closed at the bottom by a sand plug displaces the surrounding soil during the driving. Additional sand is rammed down through the casing during the extraction of the casing. The applications and limitations of the method are reviewed in the paper. The importance of checking the sand compaction piles during and after the installation is stressed. Indications of the compaction of the surrounding soil during the driving can be obtained by comparing the initial and the redriving logs of the casing as well as from the volume of sand added. A method to estimate the increase of the mean cone resistance as measured by CPT tests in sandy and silty soils is presented. The governing parameters are the volume of the added sand, the granulometric index and the initial cone resistance.

Jan 1, 2010