Search Documents

By Ivan Jackson Madura

The new Paradisus Coco Beach Resort in Rio Grande (PR) is located on an old swamp area, which has been filled with relatively clean to silty sands. The swampy deposits consists of organic silts, peat and loose fine to medium sand and silty sand. The project requires the placement of 1.0 to 1.5 meters of additional fill together with the construction of light structures. The need for the fill will trigger the development of settlements in the underlaying weak and compressible stratum. Furthermore, the susceptibility of the loose sand to liquefaction during an earthquake was considered. This paper describes the soil improvement by means of vibro-replacement, the purpose of which was threefold: reduction in total and differential settlement, acceleration of settlements during the surcharge period and densification of the loose sand to reduce its liquefaction potential. The predesign is presented together with relevant construction details of the preliminary trial areas from which the final column diameter and grid spacing were derived. Instrumentation together with settlement observations during the surcharge period are presented as well and compared with the initial predictions.

Jan 1, 2002

By Lance A. Roberts

Micropiles are commonly utilized for applications other than foundation retrofit. In bridges, for example, micropiles can serve as the permanent foundation elements or can be used in temporary support applications. In this paper, a case study on the use of micropiles for the 18th Street Expressway Bridge rehabilitation/repair project in Kansas City, Kansas is presented. In the project, micropiles were utilized for support of six temporary jacking structures, which allowed the bridge to be lifted while repairs were completed. A group of six micropiles was required to support each jacking structure. The required compressive service load per micropile was approximately 300 kips (1300 kN) and the settlement of the micropiles under the service load was to be limited to 0.5 in. (12.7 mm). Two field compression tests were conducted as part of the project. The field load test data was integrated within a soil-structure interaction capacity approach in order to analyze and permit the shortening of the design bond length for the production micropiles.

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 Sridhar Krishnan

This paper presents the results of a comprehensive pre-production pile testing programme for the US$ 800 million 1400MW Coal-Fired Jimah Power Plant Project in Negeri Sembilan, Malaysia. The testing programme included high-strain dynamic testing and fully instrumented static axial and lateral load testing of driven prestressed concrete piles and bored cast-in-place piles. A highlight of the testing programme was the pioneering use of the Global Strain Extensometer (GloStrExt) Method, a deformation monitoring system that uses advanced pneumatically- or hydraulically-anchored extensometers and a novel analytical technique to monitor loads and displacements down the shaft and at the toe of driven prestressed concrete piles. The experience with the testing programme for the Jimah Project also demonstrates the possibility of achieving notable breakthroughs, not only in the monitoring, evaluation and reporting of pile foundation behaviour dynamics but also in our understanding of the mechanisms that underpin such behaviour. These significant gains are undeniably a direct result of the committed and co-operative relationship among the project owner, design/builder, specialist piling subcontractors, pile suppliers and pile instrumentation and testing specialists.

Jan 1, 2006

By Sam X. Yao

The underwater concrete technology has historically evolved largely through a trial-and-error process of constructing marine works. Many outstanding examples exist of high quality concrete placed underwater. However, failures also occurred and led to excessive cost and/or schedule overruns. These failures were largely due to improper concrete mix design or improper placement. The problems may have occurred because proper underwater concrete construction techniques and experience have not been widely disseminated. This section focuses on technical issues of underwater concrete mix design, concrete production and placement, and quality control.

Jan 1, 2013

By Hiren J. Shah

The urban environment and geology create unique challenges for design and construction of deep foundations. The effect of these is prominently experienced in New York City. Three such project case histories are presented in this paper. The first project is a multi-use development. Relatively unusual glacial geology was observed at the site during the subsurface investigation phase. This played an important role in the selection of deep foundations as well as during construction. The design and construction aspects of the pile foundations, settlement estimates, a pile drive test program during design, piling equipment and production pile installation are discussed herein. A relatively smaller project is the second case history. A combination of drilled and driven deep foundations was employed in one area of the project due to its unique conditions. In another area of the project, an addition to a structure required the use of supplemental foundations to resist new additional loading. Tight space and load sharing with the existing foundations were important considerations in the design and construction. Finite element modeling of the existing and completed structure was performed which was an interesting aspect of the project. The third project case history involves a very large multi-billion dollar project in which various different types of deep foundation elements were used. The aspects requiring the use of such a variety of types and sizes of deep foundation elements included: geologic conditions, re-use of existing foundations, protection of adjacent infrastructure, construction staging, restricted space, loads, deep excavations, cost and schedule.

Jan 1, 2011

By Miklós Kovács

A new type of the cast in situ piles is introduced. The installation of the new pile is based on a pushing in/gaining back procedure. A temporarily closed tip element with square shaped cross-section being attached to an upper circular shaft tube is vibrated into the soil. The steel armature is embedded. Concrete is poured into the tube and, the whole structure is gained back while the tip is in opened position. The width of the tip is less than or equal to 40 cm. The maximum length of the pile is about of 14 m. Great bearing capacity is resulted from the double soil compaction effect. No spoil is generated and, the pile construction can be controlled. The paper presents the results of four loading test at three sites with some soil data.

Jan 1, 2002

By Mario Terceros H, Bengt H. Fellenius

"ABSTRACTThe city of Santa Cruz, Bolivia, is historically dominated by houses and three to five storey buildings.The geology in and around the city is such that even very light buildings need to be supported onpiles. The recent increase of the Bolivian economy, notably that of Santa Cruz, has created a demandfor new residential as well as office and industrial buildings, which mostly consist of multi-storey orhigh-rise buildings with significantly larger foundation loads. Foundation piles have become largerand longer, and the load on individual piles is increased. The development has resulted in an increasein the demand for more sophisticated design and construction methods and stricter approach toverifying the quality of the construction processes and results.This paper describes to geology of the Santa Cruz region and how the geotechnical conditions areconsidered in the design and construction of piled foundations. The improvement of past constructionand design techniques, based mostly on bored piles constructed with bentonite slurry, is beingreplaced with new methods of constructing bored piles, e.g. the Full Displacement Pile (FDP) andincorporation of techniques such as enlarging the pile toe, e.g., with the Expander Body. This paperpresents the results of several full-scale tests and discusses the incorporation of the test results indesign and construction.1 GEOLOGY OF THE REGIONSanta Cruz de la Sierra is located in the eastern lowlands and sub-Andean zone of Bolivia, SouthAmerica. The area lies at an elevation of about +400 m and the geology is a Paleozoic (250 millionyears old) sedimentary basin. The soils of interest to civil engineering construction are quaternarywith the dominant minerals being calcite, silica and feldspar. The main agent is the Piray River and itstributaries. Their past meandering over the area has resulted in a sedimentation-erosionsedimentationprocess and a profile dominated by fine to medium sands with intermittent layers ofclay or clayey sand. With increasing distance from the river, the clay-containing layers are thicker.Fig.1.- View of Bolivia with location of Santa Cruz and map of Santa CruzThe upper about 15 to 18 m thick part of the profile consists of normally consolidated layers of clays,silts, sands, in various combination and thickness. Below, the soil is more homogeneous and consistsmostly of sand and gravel. The groundwater table lies typically at a depth of about 6 m in the highestpart of the city and at about 1 to 3 m depth in the lowest part of the city."

Jan 1, 2014

By Jacques Moraille

The public is asking for more aesthetic designs if they can be proven cost-effective at providing an appealing element to new dams. Lake Lenexa was designed and built around the idea of providing for basic dam functions such as flood control, enhanced water quality, recreation but also to provide an inviting community focal point for the residents to visit and enjoy; truly interact with the dam. The architecturally unique dam and ?one of a kind? spillway were designed to symbolize the water cycle as water moves from nature into the urban environment and the back to nature. A pedestrian bridge that spans the spillway offers visitors a good view of cascading pools and a fountain. The original Lake Lenexa dam layout incorporated relatively high, cast-in-place concrete retaining walls to form the spillway structure. The Black & Veatch project team performed a Value Engineering (VE) study to determine cost-effective means for implementing architectural features within the spillway, which resulted in innovative uses of construction materials not typically used in dam and reservoir construction. The VE study concluded that mechanically stabilized earth (MSE) retaining walls that are normally used for transportation projects would be a cost-effective alternative to the originally planned cast-in-place wall systems for the main spillway and stilling basins. The Black & Veatch study added value by mixing cement-kiln dust (CKD) with on-site clay soils to produce a stabilized material for use under the spillway. The CKD stabilized material properties include low compressibility, high strength and low permeability, which reduced seepage and uplift pressures under the spillway slabs. The cost savings provided by the VE alternatives reduced total costs and enabled architectural elements. The award winning dam design also used drilled caissons, expanded polystyrene (EPS) block forms, customized steel forms and external concrete vibrators to build the pedestrian bridge and upper spillway structures.

Jan 1, 2009

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 Gang Guo, Zhong Liu, Yi Zhang, Jingchun Lu

"Abstract Application of soil displacement screw pile (known as SDS pile) has been experiencing accelerated growth in Chinese deep foundation industry because of its technical advantages, environmental benefits, and cost effective as well. As bored displacement piling, SDS piles are able to perform better than non-displacement piling such as CFA plies due to changing the stress state in the soil around SDS piles during the installation. Therefore the design methods between the conventional pile type and SDS pile type have some differences. Based on the methodology research, current Chinese piling rigs, displacement augers and piling projects are introduced, and the current design approaches for SDS piles in China are also described. Moreover, the design results are verified by using full scale load tests, and a part of the research results of SDS piling system acquired in China are presented.IntroductionThe Continuous Flight Auger Pile, also known as the CFA pile, has occupied about 22% in the pile market all over the world (Van Impe, 2004; Bottiau, 2006). The CFA piles are usually used for large diameter (600mm~1200mm) pile foundations and deep excavation projects. Whereas the small size CFA piles (400mm~500mm) are mainly applied for composite foundations in China. In the past 10 years, the new technology of soil displacement screw piling has been applied worldwide (Prezzi et al., 2005). And it is also extensively used for high-rise buildings, industrial plants and railway projects in China (shown in Figure 1)."

Jan 1, 2014

By Maurice Bottiau

"Abstract When addressing the performance of deep foundations, many parameters play a role, from adequate soil investigation to performance monitoring and testing. The correct understanding of pile construction, though, remains crucial. After a long period of empirical design and regulations, the last decades have been the ones of theoretical considerations and extensive codes writing. The interaction between technology and design, however, still plays a determinant role. The introduction of hydraulics and the exponential increase in available power on one hand, the miniaturization and the introduction of electronics in control and monitoring systems on the other hand have exerted a major influence on new foundation systems or the evolution and control of existing systems. It appears important to try to take execution related parameters and their control during execution more deeply into account when assessing the final result of the deep foundations and the achieved level of safety and reliability. In this contribution, we will try to analyze how systems, equipment and pile production monitoring and testing can influence the pile performance, and if/how this influence could/should be translated in adapted safety or installation factors. This analysis will run through different categories of piles: driven, augercast and displacement auger piles and bored piles. INTRODUCTIONThe global performance of a deep foundation depends on different aspects (Poulos, 2003):1. Ground investigation2. Design and analysis3. Construction4. Testing5. Performance monitoring6. Remediation and performance enhancementThis paper intends to address the importance of pile construction and the control of it on the final performance of the pile-group of piles. There has been an increasing interest for theoretical analysis over the last 20 years, followed by an increasing impact of regulation and codes. Without denying the importance of the latter, the author wants to point out how installation procedure and project specific parameters can largely influence the reliability of the deep foundation. In this context, detailed and prescriptive standards can miss their objective of intended improvement of accuracy and reliability, but even worse they can adversely impact engineering judgment. In today’s construction world, it is possible to gather installation information which can be of outmost importance for the final deep foundations performance. Therefore, the increase or decrease of installation reliability through adequate pile testing and performance monitoring should be emphasized and should be taken into account in the codes. This is the case already in most advanced codes, but in a limited and insufficiently refined way. After reviewing how codes deal with this issue today, we will show some recent examples of unexpected results due to pile installation. We will try to put these examples into a broader perspective by highlighting some reference and/or recent literature considerations. Finally we will try to summarize how pile testing and installation documentation can increase reliability and attempt to open the debate on how codes could/should allow for more engineering judgment."

Jan 1, 2014

By Claudio Olalla

This paper relates to the foundation of a steel structure located at the San Martin de la Vega (Madrid) amusement park. The structure has more than 100 supports with various loading conditions, including important horizontal and uplift forces. Additionally, the settlement tolerances are very strict. A massive gypsum formation with interbedded clay layers and random solution great voids at various levels constitute the soil. The foundation design has been conditioned large enough these difficulties (load conditions and soil problems). The piling machine used was powerful to drill through the soft rock (UCS up to 11Mpa). The integrity of each pile had to be guaranteed by continuous recording of drilling and concrete pouring parameters. In order to fulfil all those conditions, a STARSOL type-piling rig was used. More than 4500 meters of piles were performed. The diameters of the piles were 450 and 550-mm and their depths varies from 6 to 23 meters. All piles were reinforced over their full length.

Jan 1, 2002

By D. E. Sherwood

Mr. Tamaro introduced his paper which concerned the construction of foundations for the buildings and related infrastructure of the World Financial Center on a reclaimed shoreline site at the Southern tip of Manhattan Island. This large project presented difficult design and construction problems, both geotechnical and structural. All structures were supported by foundations carried to rock. Two of the buildings were supported by conventional pier (pad) foundations constructed within diaphragm wall cofferdams. The remaining structures were supported by either piles to rock or caisson (large diameter) piles with socket depths drilled through the rock of up to 7.6 metres. Underground services, railway and proposed road tunnels all affected the installation of foundations. The proposed road tunnels for the new six lane 'Westway' would involve an excavation 12 metres deep adjacent to and under three buildings. This problem was solved by an agreement that tower windloads would be taken by the tower foundations and not distributed through the basement walls. This was achieved by a system of battered caissons founded on the rock and arranged so that adjacent caissons were founded in different rock masses. Diaphragm walls were restrained using tie backs. Ground testing indicated an exposure to D.C. stray current corrosion of all underground construction. As a result all of the foundations were isolated from the ground by non-conductive materials. In the case of piles and caissons the reinforcing for the caisson was fully protected by concrete and all outside steel used for the installation of piling was considered sacrificial and not used in the computation of long term load carrying capacity.

Jan 1, 1991

By Özgür Bezgin

This paper presents observations on the installation of drilled shafts from two construction projects and an academic study with experimental and analytical parts. The construction projects involved the use of pressurized drilling methods. The experimental part of the academic study involved the use of the auger drilling method. The analytical part of the academic study investigated the effect of drilling methods on the soil-structure interaction and the behavior of drilled shafts under lateral loads. The concept of ?free-length? is introduced for the lateral load design of pressure-drilled shafts that are thought to be fully embedded within a soil media. The academic part of the study presented herein was conducted in Rutgers, the State University of New Jersey.

Jan 1, 2009

By Jorj O. Osterberg

The Osterberg (O-Cell) Method makes it possible to separate the side shear resistance (skin friction) from end bearing. The O-Cell is placed on or near the bottom of a drilled shaft and after the concrete is poured and cured, an equal upward and downward pressure is applied. From the test, the load-upward deflection curve in side shear and the load-downward deflection curve in end bearing are drawn. Typical curves are shown where the ultimate load in side-shear is reached and where the ultimate load in end bearing is reached. Several examples of tests in which the test load reached ultimate loads far in excess of what was expected are shown. The side shear in rock sockets is shown to be much larger than generally estimated. Examples are given of where side shear is smaller than expected and the reasons discussed. Disturbance of the sides of drilled holes due to poor construction techniques and ways to avoid these conditions are considered. Examples of bottom hole disturbance are given and ways to prevent the disturbance are discussed. A graph showing the actual measured capacity of drilled shafts compared to the estimated capacity as a function of the hardness and strength of the soil or rock is presented.

Jan 1, 1999

By Sunil S. Basarkar, Dilip M. Dewaikar, Rajesh H. Gajjar

"A load transfer program AXPILE was developed for simulation of the loadmovement characteristics of socketed piles of the Mumbai reg ion. This program used empirical relationships for ultimate shaft resistance at pile-rock interface recommended by Zhang and Einstein (1998). According to their recommendation, ultimate shaft resistance at pile-rock interface is related to the square-root of uniaxial compressive strength of intact socket material by a parameter C, which ranges from 0.4 for smooth sockets to 0.8 for rough sockets. Results of three instrumented pile load tests were compared with the AXPILE generated results. The comparison of analytical and field estimates of the unit shaft resistance confirm the recommendations of Zhang and Einstein (1998) on the unit side shear parameter c,, which was found to be in the range of 0.35 to 0.67.INTRODUCTIONInstrumented pile load tests were carried out on the test piles at the Bandra-Worli sea link project in Mumbai city of western India. High capacity socketed piles were required to take up loads from the superstructure. Hence, in addition to the available toe resistance, an accurate measurement of the shaft resistance in socket portion was desired. The instrumented load tests incorporated Osterbergcell (0-cell) assisted by strain gauge instrumentation to estimate the shaft resistance mobilization in the socket portion.AXPILE load transfer program was developed for load-movement simulation of socketed piles (Basarkar, 2004). The load transfer algorithm based on Coyle and Reese (1966) was incorporated in this program, which used empirical correlations and functions to account for load transfer in piles through shaft and toe resistance.This paper compares the computed unit shaft resistance from the AXPILE program with the measured values recorded from the instrumented pile load test."

Jan 1, 2005

By Mel Febesh

Working in New York City has become the graveyard of many Foundation Contractors. Varying subsurface conditions require Foundation Contractors to be aware of the conditions at each particular site and have the knowledge and equipment to successfully complete the project. Looking back, we can see that many of the methods and much of the equipment that were commonly used in the past have been replaced with newer methods and equipment, but sometimes the old methods prove to be the most reliable. This paper will describe examples of varying conditions and construction methods in sites that are close to each other. It will also show different construction problems that are encountered when working adjacent to existing subway structures, when excavating below the foundations of adjacent structures and when ground water is encountered.

Jan 1, 2000

By Ray. K. Filip

The concept of installing a steel sheet pile retaining wall into the ground by "pressing" has resulted in the development of various equipment solutions over the last thirty years e.g. Taylor Woodrow ?Pile Master', Giken 'Silent Piler" & Tosa 'Still Worker?. Dawson Construction Plant Ltd (DCP), have recently advanced the pile pressing concept with the introduction of their 'Push-Pull' system. This advancement offers significant improvements in the quality of installation compared with traditional pressing solutions but also greater versatility, higher productivity and, most importantly, generates new opportunities through a wider range of applications for "silent piling'. This paper will focus primarily on the use of the Push-Pull concept in the construction of a unique "integral" bridge in Milton Keynes, England. Finally, the paper touches on the development of quiet, vibration-less pile extraction equipment, which allows steel to be considered the foundation material of choice for truly sustainable construction. It is no longer acceptable to leave unwanted piles in the ground.

Jan 1, 2006

By D. A. Bruce

The Deep Mixing Method is a very valuable tool for combating problems related to in situ soil treatment, improvement, and retention. Many different variations are used throughout the world, and there is a correspondingly rich technical literature on the testing and properties of the treated soil. This paper provides a synopsis of these aspects.

Jan 1, 2001