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By Bruce Haldeman

Timber has been used as pile support for structures for 6,000 years. Some means of preservation of wood go back almost that far. Timber piles support all types of structures ? some are buried below the water table; others raise a home for protection from animals or a chief's home for prestige. Millions of wood piles have been driven for bridge support. Earlier piles were driven by hand then by ingeniously raised weights. Charring, animal fats and oils have been used for preservation. Coal tar creosote and other preservative methods started only in the early 1800's and give effective protection.

Jan 1, 1984

By Jay A. Berger

Nondestructive testing of deep foundations for integrity problems made great strides in the late 1980's. Inexpensive portable computers have allowed the immediate and rapid processing of field measured acceleration records which can provide insight into the relative structural integrity of a previously installed foundation member. Although the gathering, processing and displaying of the data is now straightforward, interpretation remains at times rather challenging. This paper provides a brief introduction into the theoretical basis for data interpretation and the hardware necessary for data acquisition. Five case studies are discussed which demonstrate the varied applications of low strain integrity testing of deep foundations and the efficiency at which they are completed. BACKGROUND One dimensional wave mechanics, when applied to a linear elastic pile with a length that is an order of magnitude greater than its width, provides a straightforward basis for the interpretation of motion measurements made at a pile top. When impacted, a stress wave travels through the pile at a wave speed, c, which is a function of the elastic modulus, E, and mass density p (i.e., E=pc2). The applied load F, and particle velocity v, at a point are related by the equation F=Zv. For a cross-sectional area A, the proportionality constant Z is equal to EA/c. Because Z is a measure of the pile's resistance to change in velocity it is called the pile impedance.

Jan 1, 1990

By Romano J. Micciche

One of the largest scale uses of a multiple, high-strength steel bar tiedown system is described. Tiedowns were installed to resist hydrostatic uplift forces acting on a section of the Interstate Highway Route I-90 southern approach roadway to the Third Harbor Tunnel, in Boston, Massachusetts. Site specific information is discussed regarding design, testing, and installation of Tiedowns. Conclusions are presented regarding the overall performance of this system and the application of this type of tiedown system on future projects.

Jan 1, 1994

By Andrzej Tejchman

Calculation of pile foundations should possibly truly reflect its real work, mainly with respect to the value and distribution of settlements, pile internal forces and bending moments within a slab. Many empirical and theoretical methods serving for an assessment of the settlements of pile group overestimate its actual values obtained from field measurements (see Tejchman et al., 2001). In the paper a simple engineering method for calculation of pile foundations is presented. The method takes into account the interaction between the slab and a soil together with the phenomenon of non-uniform deformation of the soil-pile subsoil, particularly under large foundations. In the method the scheme of the slab resting on one-parameter elastic subsoil is assumed. The comparison of the calculation results for existing pile foundation with the field measurements shows good agreement between those values.

Jan 1, 2002

By Sugie Prawono

Jacked pile is the only piling system in which the load capacity of the pile, at any penetration depth, could be monitored directly during its installation process. Each installed pile could have a graph of jacking load versus depth of penetration. For safety purposes, the maximum applied jacking load during installation of a pile could be assumed as the minimum load capacity of the pile. This load capacity will increase with time since the drop in soil strength due to the installation process will recover later on. In order to determine accurately this jacking load, a research was carried out by comparing the load capacity of a pile at certain depths to the jacking load recorded during the installation process. The load capacity could be calculated using cone resistance, qc, and local friction, fs, from Dutch Cone Penetration Test. A graph could be drawn of the load capacity against the depth. By applying a correction factor, a, to the data of local friction, the calculated graph could be matched to the graph of recorded jacking load. The a factor is found to depend on the soil type, which is in this case, represented by the magnitude of cone resistance. The soil type is divided into 3 categories according to qc values (qc < 500 Kpa; 500 Kpa < qc < 2000 Kpa and qc > 2000 Kpa). Graphs of the a factor versus depth and a sample of calculation are presented in this paper for easy application.

Jan 1, 1999

By Gerry Houlahan

"The 2015 Outstanding Project Award (OPA), which recognizes the superior work of DFI members, was awarded for the San Francisco- Oakland Bay Bridge New East Span. The award was presented to representatives from Caltrans and the T.Y. Lin International/Moffatt & Nichol Joint Venture at the DFI 40th Annual Conference on Deep Foundations in Oakland, Calif. A committee selected this project based on size, scope and challenges of the project; degree of innovation and ingenuity exercised; and the uniqueness of the solution to the difficulties of the job. A bridge across the bay between San Francisco and Oakland was proposed as early as 1872, but it took until November 12, 1936, until it became a reality. The bridge spans to the west of Yerba Buena Island were conventional suspension spans, while the east spans used a steel cantilever truss design and simple steel truss spans. This double-deck bridge served the Bay Area well until 1989. In that year, the magnitude 7.1 Loma Prieta earthquake damaged the East Span of the San Francisco-Oakland Bay Bridge. The resulting interruption to service across the bay demonstrated the vital role this bridge plays in the economic and life safety activities of the Bay Area. The project owner, California Department of Transportation (Caltrans), determined that the safest, most cost-effective solution was a total bridge replacement. The Engineer-of-Record, T.Y. Lin International/ Moffatt & Nichol Joint Venture, working closely with Caltrans, the Metropolitan Transportation Commission (MTC) and the California Transportation Commission (CTC), was charged with developing a comprehensive design strategy that met the project’s stringent criteria for seismic safety. These criteria included the new bridge’s designation as a regional Lifeline Structure that must open to emergency traffic shortly after the occurrence of a 1,500-year return period earthquake"

Jan 1, 2015

By D. P. Nicholson

The current phase of office development at Canary Wharf in the London Docklands includes twelve multi-storey buildings varying from eighteen to forty stories in height. The area of Canary Wharf South comprises five multi-storey buildings with low level in fill podium and garden areas. Three of these multi-storey buildings have "pile-cap" designs where the entire building load is applied to the piles. The remaining two buildings have "piled-raft" designs where allowance is made in the design for part of the building load to be transferred to the raft formation. Using a piled-raft design approach has enabled savings to be made on the number of piles used below the raft. This paper describes the calibration analysis undertaken to validate the design method. The ground conditions at the Canary Wharf site are typically fill and recent gravel deposits over the overconsolidated clay and sand of the Lambeth Group. Below these strata is the Thanet Sand. The Lambeth Group provided the founding layer for the raft and contributed to the pile shaft resistance. The Thanet Sand stratum provided the bearing layer for the 1.5m diameter base grouted bored piles. The piled-raft design required an assessment of the building load transfer through the raft to the formation layer. This load transfer led to significant increases in effective stress in the soil below the raft and thence a corresponding increased the capacity of the piles. This interaction of the raft with the prepared formation contributed to between 27% and 45% increase in total vertical load carrying capacity of the piled-raft substructure compared with the pile-cap design method. The development of the piled-raft design was carried out in three main phases: ? Development of the approach and validation analyses. ? Design work on various schemes resulting in detailed design packages. ? Validation analyses using full 3D finite element analysis (presented herein). The validation of the piled-raft design approach was initially carried out against published case histories for piled-raft interaction. To improve on the validation work a full 3D finite element analysis of a simplified pile raft and superstructure (which contributes stiffness to the raft) was undertaken; the analysis included only a quarter of the structure due to assumed symmetry of the structure and vertical loading. This 3D validation analysis is presented herein. The analysis was carried out using the Oasys LS-DYNA finite element program. Prior to carrying out the analysis of the piled-raft an initial finite element analysis was carried out to back analyse a fully instrumented field pile test providing accurate modelling of a single pile performance. This back analysis allowed confidence in the soil parameters used in the 3D model; comparisons of shaft and base resistances between the pile test and the FE model calculations for the single pile are presented. The parameters provided in this work were then carried into the full 3D model of the piled-raft. The 3D model of the piled-raft structure included 18 piles (12 full piles and 6 half piles on an axis of symmetry of the model).

Jan 1, 2002

By Athena C. Denivo, Pablo V. Lopez, Michael McMaster, Sissy Nikolaou, Alfred H. Brand

"The paper presents the history of development of the United States Tennis Association (USTA) site, focusing on geotechnical, geoseismic, and foundation engineering challenges associated with it. The site is located at the Flushing Meadows Corona Park area of Queens, New York. Now home to the Billie Jean King National Tennis Center (BJKNTC), the site used to be a biologically rich, tidal salt marsh that extended south from Flushing Bay and overlaid an ancient buried valley. In early 20th century, Brooklyn Ash Co. was contracted to fill the marshland with cinders and furnace ashes. F. Scott Fitzgerald describes the “Valley of Ashes” as “a fantastic farm where ashes grow like wheat into ridges and hills and grotesque gardens; where ashes take the forms of houses and chimneys and rising smoke, and finally, with a transcendent effort, of ash-gray men who move dimly and already crumbling through the powdery air.” In 1939 the site was leveled and filled to host the World’s Fair and refilled again for the 1964 World’s Fair.The USTA moved to the site in 1978 and in mid-1990’s constructed the 23,000-seat Arthur Ashe Stadium (AAS). Currently, USTA has a Strategic Vision Plan venue with several interconnected construction projects including buildings, infrastructure upgrades and improvements to site circulation. In addition to a historical walkthrough, the authors will discuss technical challenges of supporting these developments through layers of fill, thick organic silty plastic clays and regional varved soils with bedrock found 300 to 400 feet deep. The subsurface is not only a weak foundation medium, but is susceptible to large amplification of seismic waves propagating from the bedrock during earthquakes. The developments are usually founded on project-specific pile foundations that carry static loads in deeper layers and accommodate lateral demands and performance objectives. Engineering innovations from the most recent development, the roof structure over AAS, will be discussed."

Jan 1, 2016

By Tracy Brettmann

The use of rock-socketed Augered Cast-In-Place (ACIP) piles is new to the Austin and central Texas region. This case history describes the design methodology, load test results, quality control procedures and the rate of production pile installation for the first large commercial project where ACIP piles were used in Austin. The piles were 24 inches in diameter and extended through about 45 ft of alluvial materials to be socketed 6 ft into limestone. A full-scale instrumented load test was performed on a test pile that was loaded to 452 tons and held for 24 hours. Telltales were installed in the middle and the tip of the test pile. As part of the overall quality control procedures, singlehole sonic integrity logging was performed on the production piles to verify structural integrity during pile installation. During pile production, an average of 14 piles per day were installed, which is approximately seven times faster than the original design that consisted of drilled shaft foundations.

Jan 1, 1998

By John R. Grillo, Gordian Ulrich, Franz-Werner Gerressen

Most geotechnical construction professionals are aware of piling using hydraulic drill rigs and the so-called Kelly drill mode. Kelly drilling has many advantages as it can work with a wide range of tools facing almost all types of soil and rock conditions. Kelly drilling can also deal with diameters up to 10 ft (3.00 m) and bigger or depths of more than 330 ft (100 m). Nonetheless, there is a concern about Kelly drilling as it is a relatively slow installation process. Therefore, an alternative piling method like Cased CFA (CCFA) Piles (Cased Auger Cast Piles) provides a significant advantage in terms of installation performance, schedule and cost saving potentials. Major application for the Cased CFA system is the secant pile wall construction. Against the traditional secant pile wall systems like fully cased bored piles or CFA secant piling the Cased CFA secant pile wall system has the advantage in cost and time against the fully cased system and in quality against the standard CFA system. This paper will describe the methodology and installation process in general as well as first reference projects carried out in the United States. This paper will present the results in cost and schedule saving using this method. In addition, we will also describe the limitations of this method. INTRODUCTION In the changing construction environment, companies are searching for new technologies or improvement of existing technologies to complete their projects in shorter time frames to provide a good economic solution. Especially with the focus of increasing urbanization, the aim of fast construction becomes more and more important. When thinking of piling, most people will have the same picture in mind: that of a hydraulic drill rig working in Kelly drilling mode; however, the perpetual drill rig development provides a number of options for the execution of specialist foundation projects, either for foundations or for pile walls when using single pass applications like CFA, Cased CFA and Full Displacement Piling (FDP). Single pass means, in general, that the tool is pushed and rotated into the ground to the final depth in one stroke. After reaching the final depth, concreting is started and concrete is pumped continuously while the tool is withdrawn.

Jan 1, 2019

By A. Paviani

The subject of this session is "Equipment Installa­tion, Recent Developments". This is a subject which is not usually addressed at conferences of Foundation Engineering. It is rare to find sessions dealing with the technological side of deep foundations, a subject which only recently seems to have aroused sufficient interest at national and international conferences. It is therefore natural for the subject of "Equipment", or the tools used to implement the various "technologies", to be over­looked or mentioned only occasionally during the discussion of other issues. At conferences, most of the attention is attached to research and to the theoretical interpretation of the performance and behaviour of deep foundations, as well as to establishing the most suitable calculation algorithms and approaches for the study, design and control of foundation structures. It is almost as if the subject of equipment is felt to be less important or, perhaps, that it is considered to belong more strictly to mechanical engineering than to civil engineering.

Jan 1, 1994

By A. V. Rose

A redevelopment in the City of London has been constructed with a piled foundation system that is believed to be the first of its kind. The purpose of the research is to explore this novel foundation method, which involves the installation of closely spaced piles in a perimeter arrangement with a body of soil enclosed in the centre. Both centrifuge modelling and numerical modelling techniques are used.

Jan 1, 2011

By Ryan T. Smith, Anthony Sahj, Alexander T. Darnell

Every second can count when trying to board a departing flight or catch a ride-share to your final destination. Hartsfield-Jackson Atlanta International Airport is in the midst of a project that aims to cut about 13 seconds between automated people mover trains (Plane Train) that move passengers between the terminals and concourses. The project involves extending the Plane Train tunnel west from its existing terminus under the domestic terminal. Working from inside non-public areas of the terminal, Keller North America, Inc. (Keller) incorporated systems of micropile-supported steel beams and grillage to both underpin existing columns prior to tunneling and support open-cut excavation at the tie-in of the new to the existing tunnel. Dewatering aided in mining a challenging section at the start of the drive of the mixedface, sequentially excavated tunnel and an automated instrumentation system monitored the performance of the construction and its impact to the terminal. Cut and cover egress and ventilation tunnels required braced support of excavation.

Oct 1, 2022

By Venugopal B, M Kumaran, Thomas John, Vetriselvan A

The initial pile load tests are conducted to ensure the geotechnical capacity of the pile in a particular site condition. Normally kentledge method is adopted for the compression pile load tests. In this method the entire kentledge load is loaded above secondary beams which are supported by concrete blocks above the Natural Ground Level. So, it is important to ensure the SBC (for shear and settlement) of the natural ground. In one of our projects initially it was decided to go with kentledge system for initial compression load test on 56m long 1200mm diameter BCIS pile. The test load and total kentledge load were 2160t and 2700t, respectively. The soil strata mainly consisted of clay with low SPT N value and water table almost at ground level. It was suggested to replace top soil using Granular Sub-base (GSB) with good compaction in order to avoid excessive settlement of concrete blocks placed to support the kentledge weight. When the kentledge loading started, even before reaching 10% of total kentledge load, excessive settlement on the GSB layer was observed. This paper describes the problems faced during normal kentledge method and how it was overcome using the liner pile system for initial compression load tests in this particular site condition for higher test load.

Nov 1, 2022

By Andrew Middleton, Mark Wyatt

"The Brickworks Marketplace Project is a significant shopping centre development in inner north west Adelaide constructed by Badge Constructions in 2014 and 2015. The site was a former brickworks with a deep pit containing various extents of uncontrolled fill which was to remain on site, and with a remaining void up to 6 m in depth. The existing uncontrolled fill was improved using the High Energy Impact Compaction system, and the pit backfilled using a quarry crusher byproduct selected by trial and a recycled crushed concrete and bricks and compacted in deep lifts. This approach resulted in significant savings in compaction time, cost and building foundations. The settlements of various parts of the completed works have been monitored since February 2015 and this monitoring has demonstrated small settlements which meet the user’s constraints.INTRODUCTIONThe Torrensville Brickwork Markets project involved the transformation of a former brickworks and clay pit site into a regional 17,000m2 shopping centre, opening in June 2015.The site was a former brickworks with adjoining clay borrow pit. The clay pit had been partially backfilled over many years with ‘uncontrolled’ fill comprising ‘clean’ soil, bricks and kiln dust typically of the following thicknesses:??of the order of up to 7 m to 10 m but locally up to 15 m in the western part of the site??2 m to 5 m in the south-eastern part of the site; and??less than 0.5 m in the north-eastern part of the siteAnecdotal reports suggested compaction of some of the fill may have been undertaken, although this not able to be confirmed nor records obtained.Initially it was proposed to take up the existing uncontrolled fill, sort and recompact or remove to landfill, followed by backfilling in conventional means over 500,000 cubic metres of imported filling to a thickness of up to approximately 6m to backfill the former pit. This work represented a significant cost and was not economically viable.During early negotiations, the contractor proposed an alternative to retain and ground improve the existing filling on site, and to backfill the pit with fill placed and compacted in deep lifts, thereby significantly improving the economics, environmental and community impacts of the proposed works.The developer agreed to the proposal with the following performance criteria:??a settlement of =10 mm after 10 passes by the Impact Compactor (on existing subgrade areas);??a bearing capacity of 250 kPa for high level footings;??a maximum long term differential settlement of 40 mm (measured over 16 m), ie. 1 in 400; and??a minimum modulus of 40MPa."

Jan 1, 1900

By Jr. D'Angelo, Michael M. Blendy, Shawn Downey

"A grouted helical pile was used to support new buildings in the reconstruction of a large residential development. Foundation options were complicated by urban fill underlain with variable alluvial soil. A driven timber pile and grade beam system was recommended to support the new buildings. Other foundation options are also discussed. The grouted helical pile was quoted as an alternate and ultimately won the bid based on the economics and performance of the system. Data from 8 load tests was used to develop an empirical site specific relationship for determining pile capacity based on both installing torque and installation depth. Design to incorporate tolerance on installed pile location is presented. With the three phases completed, 554 residential dwelling units supported by 3645 grouted helical piles had been constructed covering 18 city blocks on the 44 acre site. IntroductionThe Philadelphia Housing Authority reconstructed the Tasker Homes housing complex located in southern Philadelphia, Pennsylvania, adjacent to the Schuylkill Expressway in the Grays Ferry area. Keating Building Corp. and Pennoni Associates were the general contractor and the structural engineer respectively. The original Tasker Homes development was constructed from 1940 to 1941 and consisted of 44 acres of primarily two and three-story residential brick buildings. These buildings were supported by a timber pile foundation system. The structural condition of the buildings supported on the timber piles was generally good in comparison to areas outside the buildings. These areas had settled possibly up to 2-feet in places due to the heterogeneous nature of the urban fill."

Jan 1, 2005

By Burt G. Look, David W. Lacey

"Certification of foundation capacity during the construction phase is often assessed by strength or weathering state descriptors based on visual observations. This case study used the Point Load Index (PLI) test as a quantitative tool in the construction certification of a pile’s design capacity. Construction phase tests were completed on irregular sized rock samples whilst comparable design phase testing was completed on intact rock core samples. Statistical comparisons were made to assess the repeatability between the PLI tests, with best-fit Probability Distribution Functions (PDFs) determined for both datasets. Pronounced differences were observed based on the PDF adopted to characterize the PLI dataset, the consequence of which would be a significant change to the pile’s design capacity. The adoption of the lower quartile value is shown to satisfy both design conservatism and construction simplicity requirements. The commonly held belief that rock samples produced during socket excavation may be biased towards the higher strength portion of the rock mass, is shown to be invalid for this site. As the central bridge piers were certified using Plate Load Tests (PLTs), the resultant load-settlement relationships were compared with the PLI strength assessments made for similar materials recovered from the adjacent abutment piles.INTRODUCTIONThe upgrade of the Foxwell Road Overpass across the Pacific Motorway in South East Queensland required the duplication of an existing four span bridge structure. The foundations of the new bridge included the installation of 1.2m diameter cast in place (bored) piles at the bridge abutments and 900mm diameter cast in place (bored) piles below a retaining wall to be constructed adjacent to the existing abutment.The site geology was dominated by the Palaeozoic Neranleigh–Fernvale Beds, predominantly comprised of argillite, sandstone and greywacke. Limited soil materials existed at the site, with Extremely Weathered (EW) rock typically encountered within metres of the existing ground surface. The exception to the existence of shallow rock were locations where existing filling of the site had occurred – i.e. approach embankments to existing bridge structure.Capacity of pile sockets is typically assessed onsite by descriptive rock strength or weathering assessment. Such descriptors encompass a wide range of values and lack precision. Due to the subjectivity of such assessment techniques – a factor of 3 is often observed in terms of strength assessment based on one’s interpretation of rock strength descriptors alone – uncertainty on site often occurs regardless of whether a lower bound, average or other characteristic design parameter applies."

Jan 1, 1900

By Ramin Motamed, Farshid Ghazavi, Joseph A. W. Toth

"Post-disaster reconnaissance of areas affected by earthquakes has documented extensive damage to buildings with shallow foundations located in liquefaction-prone areas. Currently, estimation of liquefaction settlement is based on empirical correlations that evaluate settlement in the free-field environment and are based on one-dimensional consolidation. However, observations have shown that liquefaction settlement under buildings can be considerably greater. This research is based on a series of 1- g shake table experiments using a transparent soil box to reproduce liquefaction-induced building settlement. Building settlements were evaluated using a scaled model of a building foundation representing a 1-2 story building. Comprehensive parametric study was carried out to establish the effects of several parameters on free-field and building settlements such as building width and thickness of liquefiable soil layer. The experiments utilized accelerometers and pore-water pressure sensors to monitor ground accelerations and buildup of pore-water pressures in both the free-field and model building footprint. Results of these experiments are compared to available centrifuge tests and field observations and conclusions are drawn with respect to the potential scaling effects. Lastly, this paper discusses the feasibility of installing helical piles as a mitigation strategy to reduce the building settlements by presenting some of the exploratory experimental data obtained from this series of 1-g shake table tests.INTRODUCTIONThe 2010-2011 Canterbury earthquake sequence and the 2011 Great Tohoku earthquake are some of the most recent examples where large numbers of low-story structures sustained damage resulting from liquefaction-induced settlements. This damage has commonly been observed in residential and commercial areas developed over loose, unconsolidated and saturated coarse grained soils resulting from both natural and man-made deposits. Damages incurred from the 2010-2011 Canterbury earthquake sequence occurred in the largely unconsolidated fluvial environment bordering the Avon River in Christchurch (Henderson 2013). Similar damage was also incurred during the 2011 Great Tohoku earthquake where liquefaction of soils occurred in both young alluvial deposits and fill materials (Ashford et al. 2011). Figure 1 presents typical modes of failure to structures resulting from the effects of liquefaction. Current practices in evaluation of liquefaction settlement rely on empirical correlations (Tokimatsu et al. 1987; Ishihara et al. 1992) developed for liquefiable soils in the freefield environment (Dashti et al. 2010a). However, recent observations of the performance of foundations suggest that settlement of rigid shallow foundations in liquefiable soils are commonly greater than those predicted in the free-field. Therefore, new correlations should be developed to better predict the degree of settlement of shallow foundations in liquefiable soils. Current research is beginning to focus on the mechanisms of settlement during liquefaction in regards to confining stress, pore-water pressure and shear stress induced from foundations (Dashti et al. 2010b)."

Jan 1, 2016

By A. Rod Kern, Michael A. McNicholas, Yaser Taheri

Deep foundations were required for construction of an 18,000 ft2 (1,672 m2) 4-story office building and an adjacent 23,750 ft2 (2,206 m2) 5-story parking garage in Queens, New York due to an existing uncontrolled fill layer ranging from 15-20 ft (4.6 - 6.1 m) in thickness beneath the building footprint. The geotechnical engineers for the project initially selected auger cast-in-place (ACIP) piles over driven piles to limit the impact of noise and vibrations on the surrounding neighborhood. Ultimately, drilled displacement piles (DDP) were installed since this method offered a more economical solution that would generate the required pile capacity with shorter drill depths and would also mitigate spoils volume. During installation of test piles by the geotechnical contractor retained for the foundation work, multiple unanticipated soil conditions were encountered that would adversely affect the constructability of the piles. The existing fill contained significantly more natural and manmade obstructions than expected and the underlying glacial soil became too dense to penetrate at shallower depths than anticipated. This paper discusses how these issues were overcome through pre-drilling and the use of detailed instrumented test pile data coupled with in-house engineering capability to proactively re-evaluate minimum pile lengths at any given location and keep the project on track. INTRODUCTION Geotechnical work in the New York City market presents soil conditions that can be highly variable and challenging due to the presence of uncontrolled urban fill placed over the native soils. Construction in this area can therefore pose many unforeseen challenges, even with detailed geotechnical analysis being performed at project sites. A case in point is a construction site in Queens, New York. The proposed site development consisted of construction of a 4-story office building with a footprint of 18,000 ft2 (1672 m2) and a stand-alone 5-level parking garage with a footprint of 23,750 ft2 (2206 m2), together with associated new pavements and utilities. The site is bordered by a mix of commercial buildings and residential properties on all sides. Depth of the uncontrolled nature of the fill extended up to 20 ft (6.1 m) below street grade. Given the significant cost associated with removal and replacement, deep foundations were recommended to bypass the unsuitable soils and support the structures at depth where good bearing material existed.

Jan 1, 2019

By Ed Revoort, Robert Schippers

In Rotterdam in the Netherlands the project ‘De Zalmhaven’ is being developed. The project consists of the realization of houses, parking facilities, two residential towers of 70 m and a residential high rise of 215 m. An artist impression for the project is given in figure 1. For the high rise a new development in the use of large diameter, drilled piles with a steel casing has been successfully utilized. In this article the installation method of 65 m long steel drilled piles in two consecutive sections is presented. The settlements for the building (and the influence on its surroundings) have been analyzed in detail using 3D Finite Element calculations, which will also be discussed. Finally there is focus on the results of settlement measurements carried out during construction in relation to the settlement prognosis.

May 1, 2022