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By Gordon King

This paper presents a case study of large diameter continuous flight auger (CFA) piles and drilled shafts utilized for foundation support of a series of heavily loaded cement plant structures at the Suwannee American Cement (SAC) Plant in Branford, Florida. The high loads and exacting total and differential settlement criteria when combined with a highly variable subsurface geology provided a challenging design scenario. Fully instrumented static pile load tests were performed to determine design parameters in the variable weathered limestone bedrock. Ultimate side friction values ranged from 2 to 8 tsf within the limestone, resulting in the requirement for CFA piles up to one meter (approximately 40 inches) in diameter and socket lengths of up to 40 feet. At several localized areas, the limestone bedrock was in excess of 60 feet below grade, requiring the use of cased drilled shafts to depths on the order of 80 to 90 feet. An integral part of the production pile installation was the use of instrumentation to monitor drilling and concreting parameters. Calibration of drill rates, torque and auger rotation with rock quality was performed to allow monitoring of the soil stratigraphy at each pile location. When combined with the results of the instrumented load testing, the monitoring of drilling parameters allowed confirmation that sufficient socket length was achieved within the quality of rock present at each and every pile location.

Jan 1, 2003

By David C. Kraft

Atlas Systems, Inc. (ASI) resistance type piers were used to underpin a 100 year old historic structure at Fort Monroe, Virginia. This 3-story structure with basement was underpinned with 155 steel tubular push piers (4" OD) that were hydraulically installed to depths ranging between 90 and 110 ft. and to installing forces in excess of 60,000 lb. Project requirements included lowering the basement floor by 1-1/2 ft. and constructing new footings and adding stem walls to connect to the existing masonry walls. Additionally, the underpinning piers were temporary which required the development of a decoupling system to permit the transfer of the building loads from the underpinning piers to the new footings. The structural loads at the foundation level required a c. to c. pier spacing of 3.75 ft. in order to meet project requirements of a minimum Factor of Safety of 3.0 on the pier load capacity. Project requirements included a load test on the selected underpinning pier (ASI - AP2 4000.219) in order to establish installation depths for seating the piers to 60,000 lb. The project was successful in supporting the full load of the structure during the construction phase. Considerable savings in time and cost were achieved as well as avoiding any vibrations or noise during installation of the piers.

Jan 1, 2002

By Brunella Recinto

Pile loading tests are carried out with two main objectives: 1) evaluating the ultimate resistance; 2) checking the behaviour of the pile under live load. In the first case and particularly for large diameter bored piles the cost of a loading test may be very high. In the late '80s, a new method to perform static loading tests was proposed. It is based on the use of a sacrificial hydraulic jack placed at the pile toe. The device, internally pressurized, expanding applies an upward force on the pile shaft and an equal but opposite downward force on the soil beneath the pile toe. This device is well known as Osterberg's load cell, shortly O-cell. The obtained results are typically summarized in two separate load-movement curves: one for the shaft side shear resistance and another for the toe resistance. The two curves are used to build what is generally named the "equivalent head load-movement curve" relying upon two hypotheses: - the pile is rigid; - the load movement relationship for the shaft is not affected by the direction of movement. The former assumption can be easily removed, while it is not possible to remove the latter. On the validity of this latter hypothesis, comparisons between conventional head loading tests and toe loading tests could be very helpful. Unfortunately in the literature there are only a few case histories and most of them are also poorly documented. In order to explore limitations and potentialities of the new testing method, a finite element model has been set up. Results of simulations of conventional head loading tests and of O-cell tests are analyzed, discussed and compared.

Jan 1, 2003

By Hiren J. Shah

Across much of New York City, the geology of glacially deposited soils follows a common sequence. Outwash sands generally overlie varved silts and clays, which lie above a basal till deposit underlain by the bedrock. Pile foundations at projects with such typical stratigraphy generally develop their axial capacities by extending below the fine-grained deposits into the till or the bedrock. Contrastingly, at a project site on the Brooklyn waterfront, high capacity piles were efficiently and economically installed by driving them into the relatively shallow glacial drift and till deposits which lay above thick fine-grained compressible glacial lake deposits. An unusual aspect about the foundation design at the Brooklyn project site is that, relatively short and high capacity piles were driven into the shallow glacial drift and till deposits, overlying the thick fine-grained glacial lake deposits. In order for this unusual foundation scheme to be feasible and economical, the piles needed to achieve their driving criteria in the upper strata. Consolidation settlements in the lower stiff and over-consolidated glacial lake deposits below the pile tips had to be relatively small. The paper discusses the unusual stratigraphy in this area of Brooklyn in greater detail with geologic profiles and engineering characteristics of the glacial strata. It also discusses the design aspects of the pile foundations, settlement estimates, a pile drive test program during design, results of the static load test program during construction, and production pile installation results.

Jan 1, 2008

By M. Y. Xia

In this paper, based on the Theological tests of the interface between clay and concrete, an interface Theological model is proposed and is used in the finite element analysis which takes soil as viscoelastic mass and Theological effect of the interface between diaphram wall and ground into consideration. Its results are compared with those without an interface element, without considering the relative creep displacement. Close attention is paid to the variation of wall with time under the condition of various interface shear stiffness and viscous sliding coefficient, and their effects on the wall bending moment are primarily verified in the paper. The change of wall bending moment with time, trench heave and wall displacement in different excavation depth, bracing position, parameters for soil are also studied.

Jan 1, 2010

By Maurice Bottiau

When dealing with displacement auger piling, some general and fundamental issues have to be considered, irrespective of the system. More than with other pile types, the interplay between the soil conditions and the design and execution is of outstanding importance. This paper intends to address these issues and to summarize some critical matters in terms of design, execution and control such as : ? Importance of a reliable soil investigation ; ? Summary of the design as it is addressed in Europe for this category of piles ; ? Criteria for a good choice and control of the correct asset of the piles ; ? Importance of the concreting phase; ? Relation between the power and the engine characteristics of the drilling equipment with the final bearing capacity. For each of these issues detailed examples will be given as well as results of load tests and in-situ control during execution.

Jan 1, 2003

By Lucian L. Bogdan

"SummaryActive loaded strand anchors are often used for slope stabilization, retaining walls or tiedown anchors. Normally, strands are tensioned against the structure and wedges are locked inside the anchorages at a certain lock-off load. During the life of the structure, anchors can receive additional loading during a surcharge, seismic event or other activity on the structure.In order to have a reliable ground anchor system, the strand must not slip through the anchorage wedges during its service life. Strand slippage has been reported during lock-off, when dirty wedge plates and wedges have been used. Low lock-off loads are believed to contribute to strand slippage too. Since the initial lock-off load for a ground anchor is usually lower than the lock-load for an equivalent capacity tendon in other types of post-tensioning construction, there is a concern that strand slippage may occur if the load on the anchor increases above the initial lock-off load.Corrosion protection grout, placed after the anchor is locked off, fills the pocket and surrounds the strand and wedges. Some anchor installers believe that the grout will prevent the anchorage from developing additional capacity if the load increases above the initial lock-off load.The load-carrying capacity of an anchorage depends on several factors. Most important are: initial applied load, anchorage geometry, friction between wedge-anchorage-strand and condition of the contact surfaces.The ADSC Anchored Earth Retention Committee considers that the industry should know how wedges behave once the permanent strand anchors are stressed and grouted inside the transition pipe, between wedges and inside the grout cap."

Jan 1, 2005

By Michel Bustamante

The original Cistercian Lure abbey situated in eastern France and built in the second half of the 16th century, has become nowadays an administrative building. Because it has been founded on poor ground conditions and inadequate foundation scheme, the abbey has suffered severe structural distortion. In 1992 an inspection revealed new extensive damages which led to a general refection together with a foundation underpinning. Micropiling was the selected method. Movements recorded over a period of 6 years after underpinning completion are presented.

Jan 1, 2002

By Serge Borel

An efficient design method is proposed for "piled-footing" and "piled-raft" foundation under lateral loads. It combines the methods used for the displacement design of shallow and deep foundations and takes into account the interactions between the piles and the cap or raft. This method has been applied to previous full-scale tests carried out in the United States. Two groups of six instrumented driven piles were laterally loaded several times: first with the concrete pile cap in direct contact with the soil, and then, after a thin layer of soil had been removed beneath the cap. The proposed method models well the real behavior of piled-raft foundations. It highlights the positive effect of the cap in contact with the soil, which reduces significantly the displacements and the maximum pile bending moments. These are divided by two for the analyzed case histories.

Jan 1, 2002

By Anne Fagot

Because of the risk of corrosion caused by stray currents, steel foundations and steel sheet piling are generally prohibited in the vicinity of railway structures. Steel solutions are only accepted if they are shown to meet the required design working life and if this can be achieved at an acceptable cost compared to competing materials. The influence of stray currents on various steel sheet piling designs was studied using software initially dedicated to gas and pipeline industries and cathodic protection systems. It has been successfully adapted to model stray currents affecting steel sheet piling. Corrosion rates assessed using this modeling software were considerably lower than commonly expected. Zones of potential corrosion risk were identified; specific cost-effective countermeasures could be established. The developed software tool can help to optimize the design of piling solutions in the vicinity of DC railway power systems in terms of suitable countermeasures that meet structural reliability and cost requirements.

Jan 1, 2008

By Frank Borda

Two recent projects were completed in Ontario, Canada for major hospital additions that involved excavation support of heritage masonry structures. Conventional continuous caisson wall schemes were replaced, with significant cost savings, by tied back shotcrete systems. Using a combination of conventional design and FLAC analysis, excavation support was designed to permit excavation in competent to weak soils that limited horizontal movements of the existing structures to between 3 and 8 mm. The use of vertical wall elements (micropiles) integral to the shotcrete wall to support both the vertical wall loads and the face of the excavation was deemed to significantly reduce lateral and vertical wall movements. FLAC analysis was used successfully to predict wall movements and optimize design. The shotcrete method proved to be flexible and adaptable to design changes during the project. This permitted convenient accommodation of changes to the building geometry after excavation support had commenced. In addition the method accommodated staged demolition and excavation support of portions of the existing structure at low cost, conveniently and without delays.

Jan 1, 2004

By Jorj Osterberg

550 load tests of up to 150 MN have been completed on driven and bored piles using the Osterberg Load Cell. Because the test measures side shear and end bearing separately, much can be learned about the forces on the pile as it is loaded to ultimate capacity. At working loads side shear almost always far exceeds end bearing, with the distribution of shear and bearing greatly affected by disturbance occurring during drilling operations. Since much less movement is required to mobilize side shear than end bearing, most of the bearing develops after the working load is exceeded. Thus with insufficient bottom cleaning, safety against excessive settlement can be considerably reduced. Improved methods of drilling, hole cleaning, rebar cage installation and concrete placement are discussed. For rock socket piles it has been found that the ultimate test load far exceeds the working loads in most cases. This is almost always due to greater penetration into the rock than is required for adequate safety against excessive settlement. Factors affecting rock socket capacity are discussed. Increase of side shear and ultimate capacity with time is discussed. Case histories for driven and bored piles in soil and rock sockets are described.

Jan 1, 2001

By Saba Mohan

This study presents results based on the Pile Installation Demonstration Project (PIDP) that was conducted as a part of the East Span San Francisco-Oakland Bay Bridge Seismic Safety Project. For the three full-scale pile installations, two different high-energy hydraulic hammers were selected for the installation. However, these hammers may not have sufficient energy to drive these large diameter piles at their ultimate capacity following long-term set-up. Nevertheless, these hammers were selected because, soil plug behavior, the generation of excess pore pressures and remolding of soil during driving were expected to reduce the shaft and end bearing resistance, and therefore reduce the energy required to drive these piles to design penetration. Data collected during continuous installation driving and after a series of re-strikes at different set-up times ranging from 1 to 33 days were used as input data for CAPWAP. These results were used to estimate the soil resistance along the pile length and at the toe of the pile, and the soil pile set-up behavior. Validity of the procedures used to predict the soil resistance to driving and predicted blow counts were verified with the field observed blow counts and the energy that was delivered to the pile. Based on combined CAPWAP analyses, the soil pile set-up with time was estimated and compared with results of other methods currently available in the literature for predicting the soil pile set-up rate.

Jan 1, 2002

"Premissas BásicasCaracterísticas do concreto centrifugado(Spun concrete characteristics)Aplicação em obras de engenharia de fundações(Application engineering works foundations)Logística de fabricação e transporte(Manufacturing logistics and transportation)Emendas x uso de aplicação(Amendments x use application)Geologia brasileira, da região costeira a presença de grandes bolsões de argila mole(Brazilian geology, coastal region the presence of large pockets of soft clay)Influencia do sistema de cravação(Influence of driving system)Transferência da Energia Aplicada(Applied Energy Transfer)Estacas longas(long piles)Controles executivos (diagrama de golpes, nega, repique elástico, ensaios de carregamentodinâmico, provas de carga).(Executive Controls (blows diagram, sets, elastic rebound, dynamic load tests, load tests).)ECD – aplicação da metodologia do DIETECD - application of the methodology DIETBrazil has a highly variable geology all along its coast that directly influence the choose of foundation type, being too employed the use of reinforced spun concrete piles initially ranged in diameter from 60 to 80 cm. Over the past 10 years with the advent of investment in marine works projects began to demand a new range of piles with diameters greater than 100 cm and in the absence of amendments.On land is also very remarkable the presence of regions with large layers of soft clay, in prime areas that have been explored. A classic example is the Barra da Tijuca in Rio de Janeiro that has suffered from the housing boom growing toward these regions. In these regions it has been very common driven lengths of about 40.0 meters, which basically go through thick layers of soft material or unconsolidated and they will find strength in depth with residual soil layers or even the bedrock.The spun concrete has great qualities for application in deep cuttings resulting from the production process, which gives a redistribution of fresh concrete mass collaborating with the particle size distribution effective loss of water that is thrown to the center stake being subsequently discarded. Consequently this contributes to a reduction in the factor a/c that is directly connected to increase strength.The fact that there is a sort of concrete helps to reduce voids in the mixture, which increases the durability characteristics. This condition made it possible to employ the spin technique on poles, which are directly linked to aggressive media in large urban centers.Another very attractive feature is that the centrifuge process can work with concrete with the lowest percentage of mortar and more gravel. This concrete mix directly contributes to increasing the specific modulus of elasticity, thus allowing a greater capacity to absorb the energy of the blows transferred with less deformation.Despite the great potential of land application of prefabricated spun concrete stakes there are only three factories and its limitation is the cost of transporting manufactured for the various regions, since all transportation is done by road.For its transportation is carried out exclusively by trucks, this limits the size of cuttings being produced commonly in length from 11.0 to 12.0 meters in length and smaller compositions. For use in long piles of works is resorted to amendments in the form of metal rings, concreted near the ends of the stakes, with the transfer through steel bars in CA-50 welded to the ring. Usually run in steel ASTM A-36. Later in the work these rings are welded with coated electrode.In the case of maritime stakes are very used to drowned splicing technique, which basically consists during the spin process leave one end with the armor of the apparent stake and work together two elements and make specific, with superior resistance to the prefabricated stake.This study in addition to briefly introduce the process of manufacturing, design and logistics presents a detailed study of applicat"

Jan 1, 2015

By Artak D. Mirzoyan

Pile foundations near the edge of a slope are often required to resist lateral loads. This is particularly important for piles at abutments of bridges. However, very few full-scale tests are available that compare the effect on lateral resistance of piles installed in sloping ground to piles installed in horizontal ground. To investigate the effect of a slope on lateral pile resistance, three full-scale lateral load tests were performed on an instrumented steel pipe pile. For the first test, the pile was laterally loaded in horizontal ground; in the second test, the pile was at the crest of a 30º downward slope; and for the third test, the pile was located three pile diameters from the crest of a 30º slope. The soil around the pile consisted of well-graded clean sand (concrete sand) and was compacted to 95% of the modified Proctor maximum unit weight in all three tests. Lab and in-situ direct shear tests indicated that the friction angle of the sand was approximately 39 degrees. The pile was instrumented with strain gauges so that the bending moment versus depth profile could be determined. Pile head load, deflection and rotation were also measured. Based on the load versus deflection curves, the presence of the slope resulted in a decrease in lateral resistance of about 20% for the pile at the crest of the slope and 8% for the pile at 3D from the crest of the slope relative to the pile in horizontal ground. The presence of the slope also resulted in an increase in the maximum moment of 29% and 20% for the piles at the slope crest and at 3 pile diameters from slope crest, respectively. Analyses using LPILE with the measured friction angle significantly underestimated the lateral resistance for the horizontal soil profile. After calibrating the model with the response of the pile in horizontal sand, analyses including the slope still underestimated lateral resistance by about 20%.

Jan 1, 2007

By Ben C. Gerwick

This publication is intended to document recent innovations and technologies that have the best potential for effectively improving the quality of marine foundations while reducing the cost, time and risk of construction. Marine foundations originated in Neolithic times with the Swiss Lake Dwellers who constructed pile-supported houses, safe from invading tribes. The Queen of Babylonia built the first recorded bridge in 1500 BC across the Tigris. The foundations were large flat stones laid on the river bottom. About the same time in India, builders extended their water well techniques to the construction of ?well? foundations in the beds of their rivers. These were really the first open caissons; brick walls were built up in a circular ring while divers excavated sand from the bottom, sometimes at a depth of 100 feet. The Romans extended the clay-filled cribs of the Middle East to shallow cofferdams, which they sealed by underwater concrete made with pozzolanic cement from Mt. Vesuvius.

Jan 1, 2013

By H. R. Shen

Cushion materials are one of the most important links in an efficient piling system. In the past, little has been done in China on this problem, so engineers are still used to those traditional woods, papers and coir ropes. In this paper, the SOA of piling cushions, their testing method and parameters used in wave equation analysis for piling are briefly reviewed. The static and dynamic mechanical characteristics of 3 types of cushion material have been determined in laboratory and suggestions about testing method and evaluation of test results are given.

Jan 1, 2010

By Timothy C. Siegel

Drilled displacement piles (also known as augered cast-in-place displacement piles or augured, pressure grouted displacement piles) are installed by the displacement of soil and subsequent placement of fluid cement grout within the evacuated volume. Depending on the soil grain-size characteristics, soil behavior, in situ soil density, pile spacing, and pile diameter, the installation process can result in measurable densification and an increase in lateral stress. This paper examines the conditions prior to and following the installation of drilled displacement piles at sandy sites using the cone penetration test. The data support that the installation of drilled displacement piles results in a substantial increase in tip resistance.

Jan 1, 2007

By Takeo Asanuma, Sachihiko Tokunaga, Hirofumi Taguchi, Yasuhiro Ootsuka, Yosuke Tanaka

The Cement Deep Mixing Method (CDM Method) is a ground improving method that has been used for mainly offshore sites to strengthen the soft ground below the sea bottom by injecting and adequately mixing cement slurry with soft soil into the ground to form a ground-improving column. In recent years, the CDM Method has increasingly been adopted for ground- improving work as part of liquefaction countermeasures and earthquake-resistant reinforcement in the shallow waters of river mouths and inland waters. In consequence of that, a pontoon-mounted CDM Method (CDM- FLOAT Method) has been developed for shallow waters, which is equipped with a land-type mixing machine combined with system management equipment and a tide level-based control function. This CDM-FLOAT Method can be deployed at work sites where the conventional offshore-use CDM barge cannot be employed. This report describes the CDM-FLOAT Method and the scope of applications together with construction work procedures, and a representative case of use of the CDM-FLOAT Method is introduced as an example of earthquake-resistant reinforcement of the existing embankment of a canal.

Jan 1, 2015

With respect to liability damages, claims and costs thereof relating to or ansmg out of contamination, special or non-special wastes, hazardous wastes or pollution in connection with the performance of this subcontract: It is understood that the subcontractor's work and responsibility wholly exclude any requirement to handle such contaminants or to otherwise be responsible for such contaminants, and Subcontractor shall not be nor be considered to be a generator of such contaminants. Contractor shall indemnify, defend and save harmless Subcontractor and its sureties, from and against all liability, damages, claims and costs relating to or arising out of contamination, special or non-special wastes, hazardous wastes