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By Joram M. Amir

During recent years, the integrity testing of piles has made considerable progress. With the availability of portable and powerful computers, practically all integrity testing equipment is now digital. Using sophisticated software for data acquisition and analysis, today's testing systems can provide owners with important information regarding both the length and integrity of piles and drilled shafts. This sophistication carries a price: Very few clients, including experienced engineers, do understand the strange-looking graphs adorning the reports they get. In fact, most of them will never ask, some because they are too busy to care and others because they are ashamed to show their ignorance. This situation is well exploited by a few shrewd operators of test equipment. Facing strong competition and falling revenues, they simplify their task and cut their expenses by the following means: 1. Using old equipment until it falls apart, and then some, 2. Hiring under-qualified personnel, 3. Staying on site as little as possible, 4. Eliminating the analysis and evaluation stage altogether, 5. Confirming as-made lengths and reporting no defects.

Jan 1, 1999

By Adel Hanna

Earth pressure acting on piles driven in sand is playing a major role in estimating pile capacity. In literature, researchers entertained simplifying assumptions in estimating the earth pressure acting on the pile's shaft, ignoring the effects of pile installation and pile size. Empirical formulae were introduced based on laboratory or field test results, where major discrepancies can be found among these formulae. In this paper, the theory of cavity expansion and the finite element technique will be used to establish the effects of pile installation technique and pile's diameter on the earth pressure acting on the pile's shaft and accordingly on the values of the existing coefficient of passive earth pressure and overconsolidated ratio. It is of interest to note that pile driven technique and pile's diameter have significant increase on the earth pressure acting on the pile's shaft and accordingly on the overconsolidation ratio in case of loose or medium sands, while they may cause crushing and dilation in case of dense sand. Keywords: Single pile, Cavity expansion, Cohesionless soil, Driven piles, Numerical modelling, Finite element technique, Earth pressure.

Jan 1, 2003

By Michael J. Garlich

Steel sheet piling has a long history of use in a variety of permanent and temporary structures. Current engineering practice uses numerous publications and standards for design guidance. U.S. design guidance is fragmented, with numerous inconsistencies between design guides. To improve current U.S. design practice, the North American Steel Sheet Piling Association has initiated a project to produce a design standard that will unify design procedures and provide specification guidance for engineers and users of steel sheet piling. The wide range of uses for sheet pile structures presents a challenge in developing such a standard. Load factors or allowable stresses acceptable for a temporary retaining wall in soil may reasonably vary from those for a river cofferdam or a dockwall located in sea water. However, it is still possible to provide consistent and rational guidance for such varying uses. The standard also can address sheet pile design aspects often neglected in U.S. publications, such as vertical load capacity and resistance to loads applied parallel to the sheeting.

Jan 1, 2008

By Florian König

It is well known that the bearing capacity and stiffness of displacement piles may increase significantly with time, a phenomenon usually referred to as set-up. In cohesive soils the set-up is commonly explained by consolidation processes in which the dissipation of the excess pore pressures around the pile leads to an increase in effective radial stresses. Recent case histories show that set-up may also occur in sand over a period which exceeds by far the consolidation process. Therefore, other effects apart from the dissipation of excess pore pressures must contribute to this long-term set-up effect. This paper presents the results of a series of multiple pile load tests on prefabricated concrete piles which capture the effect of pile set-up empirically. The main characteristics of the set-up trend are shown with respect to soil type, pile dimensions and distribution over the pile length. Possible reasons for pile set-up like consolidation and stress relaxation after the end of driving are examined using a finite element model which simulates the pile installation process.

Jan 1, 2006

By Robert S. Thomas, Bernard M. Tarralle, Nasser Massoudi

"The Commonwealth of Virginia is restoring and expanding its Capitol of great historic significance. Designed by Thomas Jefferson in 1785, it is the second oldest Capitol building in the United States. The building expansion required excavations immediately adjacent to its South Portico. The building, which rests on shallow brick footings, is very sensitive to any disturbance caused by construction and excavation. A comprehensive and secure plan of operations was devised by the design team to ensure that this national monument remains unharmed by the new construction. Various construction techniques were implemented to satisfy the strict movement goal of 0.25 inch and distortion of U2000. They consisted of jet grout columns to stabilize the upper soils, compensation grouting for future foundation leveling, a tied-back reinforced concrete diaphragm wall for excavation retention and foundations, and realtime instrumentation for monitoring. This paper describes the design approach for the retention system, providing information on the various construction phases and techn iques, and reports on the movements recorded by the real-time monitoring system during the course of the project. At the time of this manuscript preparation, and the deep excavation complete to final grade, the results indicate that the extremely restrictive building movement criteria have been met. The success can be credited to detailed design, close cooperation among the project team, prudent construction methods, and real-time monitoring. INTRODUCTIONThe Commonwealth of Virginia is undertaking a comprehensive renovation and expansion of the Virginia Capitol building located in Richmond, Virginia. The Capitol building was designed by Thomas Jefferson in 1785, with construction of the original building starting the same year. The Capitol building was designated a National Historic Landmark in 1960 and was listed on the National Register of Historic Places in 1966.A part of the comprehensive renovation and expansion of the Capitol is a 25,000-square foot, two-level subterranean extension on the south side of the Capitol building, which will serve as a new Visitor Center and public entrance for the Capitol. Deep excavations were required for the construction of the new Visitor Center. The excavation required a permanent retention system to accommodate an approximately 40- foot deep excavation."

Jan 1, 2005

By Julie Clarke

In 1939 Dr. Ralph Peck criticized the Civil Engineering community for taking a bifurcated approach to the prediction of building damage due to subsurface geo-technical works. Specifically, he observed that Geotechnical Engineers concerned themselves only with subsurface issues implying that their results were largely independent of the presence and condition of the structures above. He continued that Structural Engineers charged with risk assessment of buildings approached their work nearly in isolation of below ground activities. Seventy years later, although the state-of-the-art has enabled a better understanding of soil-structure interaction, the reality remains that risk assessment from subsurface construction, is not yet an integrated activity when done on a large-scale basis. To help move beyond this, this paper proposes a new, integrated methodology for preliminary assessment that considers a three-stage process that involves the following: (1) traditional empirical relationships for predicting ground movement from tunneling, (2) recent advances in condition assessments, and (3) architectural designators related to usage and historic preservation listings. The methodology is applied to a study area of nearly 260 buildings in the city center of Dublin Ireland, in an area slated for an upcoming metro. The results are com-pared to the Environmental Impact Statement issued for the official project. Al-though the test case is for tunneling, the approach may be adapted to other subsurface construction activities including excavation and piling.

Jan 1, 2009

By Paul J. Lewis

Estimation of the axial side shear resistance of drilled shaft rock sockets is directly related to the unconfined compressive strength of the bedrock. Commonly, the mean unconfined compressive strength value is calculated from a range of laboratory test results and is used to estimate the side shear of the bedrock. This paper presents the results from a full scale axial load test performed on an 8.5-feet-diameter drilled shaft rock socket, and compares measured side shear values to estimated values for two different rock strata. Measured side shear values correlated well with the design value calculated for the ?strong? rock stratum, but did not correlate well with the design value calculated for the ?weak? rock stratum. The mean unconfined compressive strength was used to calculate the side shear in both strata, but review of the laboratory data indicates that this value may not have been appropriate for the weak stratum due to a large variation in the laboratory test results. Also included in this paper is a discussion of the subsurface conditions, the laboratory test results, and the methodology used to design the drilled shaft rock sockets for axial and lateral resistance.

Jan 1, 2013

By Prof. Dr. -Ing. habil. Sascha Henke, Johannes Beck

The growth of Building Information Modeling (BIM) during recent years opens possibilities for integrating new digitally driven design approaches. While parametric design and algorithmic design slowly gains popularity in numerous ACE-applications, e.g. bridge design, it is rarely used by geotechnical professionals. This article presents an approach for implementation of parametric design in the BIM-based geotechnical design process. The methodology is applied to pile design and enables a real time design analysis according to DIN EN 1997-1 and EA-Pfähle 2012 considering boundary conditions such as pile position and layout, pile geometry, soil stratification and soil properties. By using intelligent attributes and scripts to control, calculate and assign them, the design analysis is directly executed in the BIM-software environment, in this case Autodesk Revit with Dynamo. This BIM integrated design approach allows multi-criteria evaluations of pile designs using aspects such as costs, environmental impact or constructability in addition to the commonly examined structural analysis criteria. As the proposed models are fully parametric, generative optimization algorithms can be applied to identify the ideal design for the entirety and each of the piles. Finally, the potential and limits of this methodology with respect to modeling, analysis, simulation and optimization are discussed.

May 1, 2022

By Mike Muchard

A design phase load test program was performed at the Broadway Viaduct bridge site to evaluate load carrying capacity and constructability of post grouted drilled shafts. The program included construction, instrumentation, post grouting and load testing of three drilled shafts. Two shafts included sleeve port and plate base grouting apparatus and were post grouted. The third shaft was un-grouted and served as a control shaft for comparison of the un-grouted end bearing. The shafts were 5 feet in diameter with the control shaft at 55 feet in length and post grouted shafts at 55 and 66 feet. SPT borings at the centerline of each test shaft defined geotechnical conditions at each shaft. Test shafts were instrumented with strain gages and concrete integrity was evaluated with crosshole sonic logging. Instrumentation and data acquisition was used during the post grouting operation to fully capture the shaft behavior. Finally, Statnamic load testing was performed on all three shafts to their ultimate capacity. The fine to coarse sandy soils in which the shafts were tipped in were well suited to improvement from post grouting. Grout pressures of 660 psi were achieved with 0.08 inch or less of upward shaft movement. Subsequent Statnamic load tests showed 183 to 192 percent greater end bearing in the post grouted shafts as compared to the un-grouted shaft. The overall result showed a potential savings of approximately 9 feet to 35 feet of drilled shaft length in addition to the increased quality assurance from post grouting.

Jan 1, 2009

By Brent Wilkins

The project team was tasked with the design and installation of a deep foundation system to support an expansion to a power generating station in Glenrock WY. Cast-in-place piles installed by a fixed mast drilling platform were assessed to be the most efficient foundation system for the subgrade conditions and range of design loads for the project. It was determined that conventional augered, cast-in-place piles could not be installed to the required pile toe elevations. Subsurface materials consisted of interbedded coarse- and fine-grained soils to about 23 ft to 30 ft depth below the ground surface, underlain by carbonaceous shale (claystone) with interbedded sandstone. The overburden materials varied from very soft to medium stiff and loose to dense. The claystone was typically foliated and very weak to weak whereas the sandstone was typically massive and very weak to weak. The site characterization consisted of a variety of field and laboratory programs including soil borings with Standard Penetration Tests, pressure-meter testing, and geophysical testing. A load test program was performed involving the compressive, lateral, and tensile testing of piles ranging from 14-in to 24-in diameter. Compression test piles were instrumented with vibrating wire strain gages. The paper includes a discussion of the regional and local geologic and geotechnical parameters, particularly the results of the various in situ and laboratory test programs. The selected foundation system is introduced. Load test results are then presented along with analysis and discussion of these results with regard to performance of the piles in the claystone.

Jan 1, 2009

By Brad W. Taylor

"During the past several months, I have introduced to civil and structural engineers an innovative solution for the integrity testing of concrete using the Thermal Integrity Profiler (TIP) Wire Cable System by Pile Dynamics. While in the process of “educating” highly-trained professionals about a technological breakthrough, I ended up being educated myself about their needs for quality control/quality assurance (QA/QC). With that in mind, I would like to focus on their two key areas of concern:• How complex is the TIP installation process?• How does the QA/QC engineereffectively analyze and report TIP test results?A few months ago, during a discussion with a senior QA engineer, he asked a question that stopped me in my tracks: “Why should we do foundation testing at all?” Turning it around, I asked, “Why wouldn’t QA/QC personnel want to know everything they could about their critical infrastructure foundation?” Honestly, I didn’t answer his question nor did I fully comprehend what he was trying to say. With his experience, the engineer understood that there has not been an integrity test or a combination of integrity tests that could deliver an inside the cage and outside the cage (cover) complete data set that would provide a definitive profile of the entire shaft. Crosshole sonic logging (CSL) becomes more effective the larger the diameter of the shaft becomes, with a maximum effectiveness between 70% and 80%, but does not provide any data of the integrity of the shaft beyond a straight line between CSL tubes. Gamma-gamma logging (GGL) provides qualitative information about the concrete surrounding the GGL tube and device, and it provides information about a small percentage of the drilled shaft concrete near its outside edge."

Jan 1, 2017

By Jesús E. Gómez

A total of 260 micropiles were installed as part of a retrofit effort for two existing bridges. The micropiles consisted of hollow core bars installed under limited headroom conditions. Of the total number of micropiles, 180 were installed in submerged sand and 80 were installed in stiff, silty clay. The micropiles were drilled using a lean cement grout which was re-circulated for de-sanding and re-use. Final grout was injected upon completion of drilling to the design tip elevation. The micropiles were subject to a rigorous quality control that included grout quality testing and proof-testing of each production micropile. This paper presents a description of the procedure for installation and quality control of the micropiles. The successful proof-testing of all the production micropiles showed that hollow core bar micropiles can be used effectively in granular and fine-grained soils. Hollow core bar micropiles offer particular advantages when installed in submerged sand formations with respect to other traditional micropile types. The results of the proof load tests are presented in a companion paper.

Jan 1, 2007

By Abid Adekunte

"Whilst safety is considered to be of high priority in every aspect of engineering projects, it is equally important for designers and contractors to be continually aware of their obligations to the immediate environment and the society as a whole. These include responsibilities to minimise the amount of nonrenewable natural resources and energy used on projects, to reduce carbon foot prints on projects, to minimise the quantity of wastes produced on projects, to minimise the level of pollution on construction sites and to reuse materials and waste products whenever and wherever possible.In other words, professional engineering practice needs to be accompanied by an underlying fundamental objective to improve, restore and sustain the environment. However, achieving this objective requires continuous collaborative interaction and effective communication between the different specialists involved on every project from the early stages. In addition, developing a well-thought-out economical solution is key to achieving the sustainability aspect of the above objective.This paper focuses on the design, construction and management of a recently completed large multi-level basement scheme in Central London, with greater emphasis on collaborative approaches taken by the design engineers, commercial managers, construction managers and site operatives to deliver the most reasonably economical and sustainable solutions to the client. Solutions were based on combinations of general and specialist engineering knowledge, with due considerations for health & safety, sustainability, cost, practicality, time and community requirements.INTRODUCTIONUnderground structures have become vital components of urban life worldwide e.g. tunnels serve many water, wastewater, highway and railway schemes, basements have been incorporated into many urban commercial, institutional and residential developments, while many public underground car parks have been built to deal with the incessant problem of insufficient surface parking spaces in busy urban centres.The safe design, construction and maintenance of underground structures have been well-mastered by the deep foundation industry over the years. However, just like many other areas of engineering, aside the need to satisfy safety requirements, underground construction practice is now faced with a new set of requirements; the demand for more sustainable and cost-effective solutions, with reduced environmental and societal impacts. Designers and managers of underground construction schemes are now compelled to minimise the use of natural resources and energy, to minimise the amount of waste produced, to minimise the level of environmental pollution, noise and disruption to traffic and normal societal life at ground level around underground construction sites. In addition, the recycling of site wastes and reuse of materials have now become important aspects of underground space development. Considerable effort is being put into promoting sustainable development across the industry."

Jan 1, 2017

By Abid Adekunte

"In recent years, developers have had to deal with complexities associated with numerous cases of deep basement construction in built-up areas. Design and construction of deep excavation support systems in urbanised zones come with many technical challenges. Restricted working spaces often render the use of temporary struts as wall restraint systems unpopular, as working space needs to be maximised. Also, tie-back anchors are often inapplicable due to the existence of adjacent structures. Therefore, developing alternative restraint systems for deep basement structures in builtup areas is becoming increasingly important to the present day basement engineer.This paper is centred on the design, construction and monitoring of enabling works for deep basement structures on three sites in the United Kingdom and Republic of Ireland. Traditional tieback anchorage and propping systems were inapplicable on the sites. As alternatives, separate novel wall restraint systems were developed and adopted, to enable excavation on each of the three sites.Performances of the novel wall restraint systems, as well as the responses of adjacent structures were monitored. Numerical modelling and field monitoring results show the three alternative wall restraint systems to be safe and effective. The paper also highlights the advantages of the novel solutions over conventional methods.INTRODUCTIONRecently, deep basement structures have become popular components of urban building developments. As pointed out by Pearlman et al., 2004, this could be attributed to the inadequacy of surface parking spaces in urbanised zones, while underground parking facilities are also believed to improve both aesthetic and commercial qualities of urban structures.However, while the incorporation of basement structure into new urban development appeals to developers and architects, the engineering design and construction aspects of basement works typically come against a whole lot of complexities and challenges. As highlighted by Wong, 2002, engineering problems associated with basement construction in built-up areas are numerous, some of these include; complicated sub-soil conditions, dealing with excessive active pressures, complex temporary works, proximity of sensitive adjacent structures, high level hazards to construction workmen and surrounding community, inadequate working space, etc."

Jan 1, 2015

"Integrity tests refer to a variety of non-destructive tests (NDT) whose purpose is to measure or determine the quality and uniformity, and some- times dimensions, of cast-in-place concrete foundation elements. The tests are primarily aimed at detecting zones of poor quality concrete, voids, bulges, and/or necking.The non destructive integrity testing techniques in this section most generally used for drilled shaft testing are based on one of two physical principles - stress wave propagation or nuclear radiation. All of the stress wave methods involve monitoring a deliberately created vibration, usually of very low amplitude (strains on the order of ??). Some methods rely on direct transmission of the signal, while others rely on processing reflections of the imposed signal.The stress wave methods are inherently sensitive to vibrations from other sources, especially at frequencies that fall within the range of interest for the particular test being applied. Construction activity near the shaft being tested; such as: demolition jack-hammering, pile-driving, casing vibration, excavation and movement of track-vehicles are all known sources of interference that might render test data useless. The actual effect of such vibrations will vary with the type of activity, soil conditions and distance from the testing. The test operator must be able to recognize such interference, and the contractor should be prepared to cooperate with the testing personnel by stopping or moving the source of vibration. If this cannot be done immediately, testing should be postponed until the work in question is finished and the vibration source moved or shut down.NDT methods are not suitable substitutes for routine "topside" construction inspection as described in the Drilled Shaft Inspector’s Manual. However, these NDT methods do allow measurements of the quality of concrete placed in drilled shafts, which cannot be made from "topside" construction inspection. They should be considered supplemental to routine construction inspection as they do provide an additional level of quality control."

Jan 1, 2004

By Javankhoshdel Yacoub

Piles are often used to reinforce slopes as they increase the available restoring force when calculating the factor of safety against sliding. In this paper, a 3D model of a slope containing multiple modes of failure is reinforced using pile elements. The results of the 3D Limit Equilibrium analysis containing piles are obtained using a newly introduced coupled approach which combines the results of finite element analysis (to obtain the displacement of soil along the pile) with the traditional limit equilibrium iterative formulation. The multiple modes of failure are obtained using the novel Multi-Modal Optimization (MMO) metaheuristic method which adapts the Particle Swarm Optimization (PSO) method to search for multiple local minima in a single slope model.

Oct 1, 2022

By Alper Turan, Hesham El Naggar

"The use of aggregate pier foundation systems has become widespread as the engineering practice moves towards cost-effective ground improvement solutions that provide accelerated construction schedules. Increased bearing capacity, effective settlement control and potential for liquefaction mitigation are commonly acknowledged benefits of aggregate piers. This paper studies the mechanisms by which aggregate piers interact with each other and with the surrounding ground when excited by seismic loads. A particular emphasis was placed on the response of a raft foundation supported on a site improved using aggregate piers. Three-dimensional nonlinear finite element analyses were conducted using commercial software package, ABAQUS. Non-linear soil behaviour is modelled using a three-dimensional total stress-based bounding surface plasticity model, which is able to simulate stiffness degradation and damping increase in the soil. The soil stratigraphy considered in this study was a 30 m deep soil deposit that comprised a very stiff base layer and a shallow soft surficial clay layer. Ricker Wavelet time histories with different frequency contents are used as the excitation force in the analyses. Various area replacement ratios (ARR) for aggregate piers are studied for a square plan layout. The results presented in this study are considered to be of interest to researchers and designers in evaluating the seismic ground response of the sites improved using aggregate piers. INTRODUCTIONThe schedule and cost limitations imposed by the traditional over-excavation and replacement method for the stabilization and settlement control for poor soils resulted are underlying factors for the significant increase in the use of aggregate pier foundation system, particularly in the last two decades. Various well known advantages of aggregate pier systems including increased bearing resistance, settlement reduction, and increased uplift capacity have been studied by various authors. The use of aggregate pier systems for settlement control in soft soil deposits was studied by various researchers including Lawton and Fox (1994), Lawton et al. (1994) and Wissmann et al. (2001). Lien and Fox (2001) studied the behaviour of aggregate pier systems supporting embankments and retaining walls. The stabilization of slopes by means of aggregate piers was studied by Lien and Fox (2001), Wissmann et al. (2002). Thompson et al. (2009) reported on a performance monitoring study of aggregate pier systems supporting MSE walls. The interaction mechanism between the aggregate pier system and the surrounding soil attracted attention of various researchers. Handy and White (2006a) and (2006b) studied the changes that occur less than 2 m from centers of the piers, and further away, respectively. The support mechanism of aggregate pier systems subjected to compressive loading were studied experimentally and numerically by White et al. (2007) and Pham and White (2007), respectively."

Jan 1, 2017

By Alper Turan

The use of aggregate pier foundation systems has become widespread as the engineering practice moves towards cost-effective ground improvement solutions that provide accelerated construction schedules. Increased bearing capacity, effective settlement control and potential for liquefaction mitigation are commonly acknowledged benefits of aggregate piers. This paper studies the mechanisms by which aggregate piers interact with each other and with the surrounding ground when excited by seismic loads. A particular emphasis was placed on the response of a raft foundation supported on a site improved using aggregate piers. Three-dimensional nonlinear finite element analyses were conducted using commercial software package, ABAQUS. Non-linear soil behaviour is modelled using a three-dimensional total stress-based bounding surface plasticity model, which is able to simulate stiffness degradation and damping increase in the soil. The soil stratigraphy considered in this study was a 30 m deep soil deposit that comprised a very stiff base layer and a shallow soft surficial clay layer. Ricker Wavelet time histories with different frequency contents are used as the excitation force in the analyses. Various area replacement ratios (ARR) for aggregate piers are studied for a square plan layout. The results presented in this study are considered to be of interest to researchers and designers in evaluating the seismic ground response of the sites improved using aggregate piers.

By Tomohiro Yamasaki

"At the pre-construction foundations of the controlled waste disposal site built at the Port of Kinuura, the clayey soil account for the most, and with lesser amounts of sand compaction piles and sand mat. The cement deep mixing method (CDM) was used to improve ground impermeability and to reinforce the foundations on the seawall. Laboratory mixing and testing was performed to determine the appropriate quantities of cement additive for clayey soil, SCP sand, and sand mat. The test results indicated that maintaining the design strength of qu = 1,550 kN/m2 would require C = 100 kg/m3 of cement additive for all three soil types (clayey soil, SCP sand, sand mat). The permeability performance needed to improve ground impermeability assumes a permeability coefficient of K = 1.0×10-6cm/s. And the clayey soil satisfied the performance requirements at C = 100 kg/m3. However, to improve grand impermeability of the SCP sand and sand mat required more than 5% of particles having diameters of less than 75 µm. Thus, in the latter two cases, the required cement adding quantity was C = 250 kg/m3. The test specimens at one to two weeks after the created with a permeability coefficient of K = 10-6cm/s became permeability coefficient of K = 10-7cm/s six week later due to the effects of cement solidification. So the permeability coefficient declined about one order. The permeability coefficient three months later tends to decline continued with a somewhat lower.INTRODUCTIONBetween 2008 and 2011, the Aichi Seaside Environment Center constructed the Kinuura No. 3 offshore controlled waste final disposal site at Taketoyo in Aichi prefecture. (see Figure 1). The disposal site offers a landfill capacity of 5.21 million m3 and measures 472,000 m2 in area, of which some 344,000 m2 is a managed controlled sector enclosed within an impermeable seawall."

Jan 1, 2015

By K. Rainer Massarsch

"Part 1 of 2 By K. Rainer Massarsch, Geo Engineering AB, Stockholm, SwedenINTRODUCTIONConstruction activities, such as driving of piles and sheet piles, soil compaction or excavation generate noise and vibrations. In populated areas these can have a negative impact on the environment, disturb inhabitants and, under unfavorable conditions, cause damage to buildings and installations. This condition is aggravated by the growing public awareness of environmental issues and the increasing use of vibration-sensitive electronic equipment and machinery in industry. In many countries, environmental regulations are enforced more stringently and limit or even prohibit the use of impact or vibratory hammers. This development has restricted the use of cost-effective foundation methods, such as driven and vibrated piles and sheet piles.Vibration problems are gaining importance in many European countries and extensive research has been performed during the past decade, especially with respect to traffic vibrations (Massarsch, 2004). Significant progress has been made owing to the availability of high-quality field measurements and an improved theoretical understanding of how vibrations are generated and transmitted through soil layers. These findings can also be applied to vibration problems associated with construction activities. However, this information is not yet appreciated by the geotechnical profession and even less by the construction industry.This paper discusses the effects of ground vibrations on the surrounding soil and on buildings, with particular emphasis on the different mechanisms of damage that may occur. Guidance is given on the elements which should be taken into account in an assessment of risks associated with piling projects. A simplified method is proposed for assessing the risk of settlements or strength loss in soil deposits. Limiting vibration levels are presented, based on the Swedish standard, which can be used to assess the risk of damage to buildings. Aconcept to predict ground vibrations caused by pile driving and the mechanisms which control the propagation of ground vibrations, will be presented in the second part of this paper."

Jan 1, 2004