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By Gordon King

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

Jan 1, 2003

By H. R. Shen

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

Jan 1, 2010

By Mark Koelling

This paper presents a case history of a ground improvement program conducted in a soft soil environment and seismically active region in the northwest corner of Washington State near the Canadian border. The program was performed over several years, and provided adequate soil bearing conditions for the construction of several structures. Completed development includes separate construction of four adjacent structures, each with unique total and differential settlement requirements and built at approximate two year intervals. Site soils consist of 45 feet of loose saturated sand and silt overlying 70 feet of very soft to stiff (N60 = 0 to 7) normally consolidated clay. Adding to the complexity of the site is the owner?s requirement that all existing structures remain open and in service during construction of each subsequent structure. The paper presents the site geotechnical information and the foundation design issues. Details of a combination of ground improvement methods is presented, including stone columns, wick drains, a preload surcharge, and staged construction to provide soil support for shallow foundation construction of all structures at this site. The soil test results and settlement observations are presented along with QA/QC measures. Lastly, a brief method sustainability comment will be made.

Jan 1, 2010

By Georgette Hlepas

How often phrases like these have been made by project managers and project teams trying to explain why there has been cost growth, project delays and differing site conditions claims. But does it really take x-ray vision? Do we really approach geotechnical construction projects unprepared for the subsurface that may be encountered because we can't get the answer? Too often our industry seems to think the answer is, "yes." However, this is not because we can't understand the subsurface. All too frequently it is because a choice is made to save money or time by foregoing or shortchanging upfront subsurface investigations. This is accepting a risk at the beginning of the process and realizing it during construction. Case histories have proven time and time again that upfront investment in site exploration and constructing a ground model mitigates risk in design and construction. But how much do we prepare? What level of investigation (or investment) is appropriate? The answer of course, is it depends; how much risk are you willing to take for your project and what are the potential consequences?

May 1, 2022

By Pirooz Barar

The new Stanley Hall building will house the center for bio-engineering and technology research for the UC Berkeley campus. The structure is located at the northeast part of campus, adjacent to Donner Lab, on the west side of Galey Road, approximately 600 ft. from the Hayward Fault. The building site has a complex geological formation. To the east there are clayey soil shale formations, and to the west there is greywake shattered sandstone. The water table is at 10 ft. below grade. The structure will consist of 6 levels below grade and 8 levels above grade, which calls for an 83 ft. deep excavation on the northeast side. There is an approximately 35 ft. grade differential between the east and west sides of the building. Because of this severe grade differential, as well as high water tables, the lateral forces on the building due to uneven earth pressures would have been 2 times the magnitude of the seismic forces. To mitigate the lateral earth pressures, a permanent Soil Nailed Wall, integrated with the structural system of the building was designed. PB&A, Inc.?s in-house design program ?Winslope? was utilized to design the system and the data obtained from a rigorous monitoring program, were used to calibrate several computer runs using Plaxis program.

Jan 1, 2004

By Jeffrey A. Gebhard

As part of the design and construction of the new St. Anthony Falls I-35W Bridge, a full-scale load test was conducted on a 6 1/2-foot diameter drilled shaft in the St. Peter Sandstone. This load test helped identify shaft-rock interaction properties, including end bearing and multiple zones of differing shaft resistance for design of the drilled shafts beneath the three piers adjacent the river. The load test was designed by Load Test, Inc., Braun Intertec and the design team of Figg Bridge Engineers/TKDA and constructed by Design Build Consortium of Flatiron/Manson. Oversight was provided by the Minnesota Department of Transportation. Based on these test results, the drilled shafts supporting the St. Anthony Falls I-35W Bridge were designed to reduce risk and maximize economy for the people of the State of Minnesota.

Jan 1, 2009

By Manish Kumar

One of the recent advances in the field of testing of concrete piles is the Non-Destructive testing (NDT) of piles. This paper deals with a specific project where this technique was employed along with an extensive program of conventional testing methods to cross check the results. Conventional testing of the Bored, cast-in-situ piles involved taking full length concrete cores from piles to check physical properties such as core recovery, RQD, crushing strength and density of concrete. Additionally, a number of questionable piles were exposed and inspected and actual load tests were performed on selected piles. Concrete pour cards were used to compare actual Vs theoretical consumption of concrete. A direct comparison of the conclusions drawn from both these testing methods provided an excellent opportunity to better understand the intricacies of NDT technique. The study undertaken clearly indicated a need for developing clear guidelines and specifications for the use of this method of non-destructive testing of piles before the .method can be accepted as a useful quality control tool at the construction sites.

Jan 1, 1996

By Jeffery L. Ottesen

Early construction delays can jeopardize timely completion of subsequent work. As an early construction activity, and due to many unforeseen issues, deep foundation work inherently bears great potential for impacting the critical path of a planned construction schedule. This article describes two construction projects where delays related to deep foundation work forced the Contractor to consider various schedule recovery alternatives to mitigate those delays. Specifically, deep foundations on Vancouver BC's Millennium SkyTrain light rail extension and on a Mill Facility in the United States are discussed. This article cites examples of permitting delays, alleged design changes, differing subsurface conditions and changed construction methodology, the effect each problem had on the project, the mitigation means implemented by the Contractor to minimize adverse impacts of the problem, and Lessons Learned for each scenario.

Jan 1, 2002

By K. Oshima

In Japan, earthquakes are experienced frequently. Many buildings and structures in Japan are supported on pile foundations. For these pile foundations, the joint section between the piles and footing (hereinafter referred to as "Pile Head Joint"), where the load of the superstructure is transmitted to the ground through the piles, is important in both the design and construction of works particularly under seismic conditions. This paper discusses the state in which the force is transmitted to the Pile Head Joint, and introduces the basic construction of the Pile Head Joint, based on experimental investigation. Steel pipe piles

Jan 1, 2010

By Douglas L. Scaggs

Driving piles in under water applications has become more common place over the past twenty years. Where only a water depth reachable with a follower or dewatered cofferdam was the rule in the past, newer technologies developed for the offshore oil and gas industry have made depths of even several thousand feet possible offering new possibilities in foundation design and installation. With the new technology, engineers can now more efficiently design structures by placing foundations optimally thereby reducing weight and cost of the overall structure.

Jan 1, 2013

By Renato P. Cunha

The paper presents the results of a comparative and parametric analysis in which a numerical program developed exclusively for groups of deep foundations under general loading (vertical, horizontal and moment loads) was used. This program, developed in the doctoral thesis work of Zhang (2000), extends the finite layer method to accommodate a simultaneous general loading on top of piled raft foundations, allowing the establishment of a coupled relationship between displacements (in all three directions), rotations (in two directions), and external loads. Zhang (2000) has extensively tested and validated this program against well known case histories, but has not applied it to piled rafts overlying unsaturated tropical soil materials. Hence, this paper further explores the applicability of this program by using it to simulate the behavior of experimental field loading tests carried out at the University of Brasilia (UnB) experimental site. At this site, Cunha and Sales (1998) and Sales (2000) carried out several loading tests on small scale isolated rafts (1 x 1m) and piles (L=5m, dia=0.15m), group of piles (4 piles, raft clear off the ground) and piled rafts (1 and 4 piles underneath a raft in contact with the soil). The authors adopt Zhang's program to backcalculate, hence simulate, this series of experimental field loading tests under vertical loading. They also use this set of results to "calibrate" the program for further parametric analyses. The parametric analyses were carried out with different piled raft configurations in this same soil type, trying to evaluate their field behavior under the effect of distinct (geometric) configurations of pile distribution.

Jan 1, 2002

By Bernardo J. Jiménez, Harlem Lora, Roberto Acosta Mora

Circunvalacion Norte project is currently the most important infrastructure project in Costa Rica. It is the last segment of the urban perimeter highway. Site investigation of local geotechnical conditions were studied by SPT, CPT, pressuremeter tests and boreholes. A static load test was executed as a proof test with an associated ultimate resistance of 12056 kN (2710 kips). Drilled shaft design was done using PMT tests and axial nominal resistance varied between 4000 kN (900 kips) and 6000 kN (1350 kips). A total of 416 drilled shafts were constructed in 15 months with drill performance of 32 m/day (105 ft/day). Drilled shaft lengths varied between 4,0 (13 ft) m and 40,0 m (130 ft). Selfconsolidating concrete was used to achieve an adequate workability even in high densities rebar cages. Several site conditions proved the importance for maintenance of the working platform, predrilling of rock sockets and having spare parts to avoid increase in project’s cost. New procedures were taken to prevent concrete segregation on excavations near underground water flow. Monitoring the quality of the shafts from CSL test showed less than 3% of the shafts presented a considerable anomaly, which proved that the adopted construction method and materials were adequate. For the concrete anomalies, successful remediation was performed by means of grout at the base of the shaft with two different types of drilling methodology depending on the concrete anomaly.

By Terence P. Holman

Instrumented load testing of high capacity micropiles, followed by detailed analysis and numerical modeling, provided an opportunity for real foundation performance to be incorporated into the design of a complex urban high-rise structure. This paper discusses a design-based load testing program and subsequent analysis for micropiles incorporated into a piled raft foundation beneath a portion of a high-rise residential structure in Brooklyn, New York. Preliminary numerical analysis, performed using the commercial finite element package PLAXIS 3D Foundation, indicated that soil stiffening and transferring heavy core loads to greater depths was required to minimize the total and differential settlements. High capacity micropiles were modeled below the tower core mat to create a piled raft effect, reducing the settlements to acceptable levels. Final design of the foundation and micropiles, and final numerical analysis of the proposed foundation system required an instrumented load testing program to provide the Owner and design team with a level of comfort. The instrumented load test provided data on the evolution of load transfer, including the mobilization of significant tip resistance, frequently ignored in design, and micropile axial stiffness. Final numerical analysis of the foundation system involved refining the PLAXIS model based on the micropile behavior and load transfer mechanism observed during the load test program. The authors believe that the combination of design-based load testing and numerical analysis in this project yielded a more refined foundation system with realistic expectations of performance.

Jan 1, 2007

By M. Y. Xia

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

Jan 1, 2010

By Andrzej Tejchman

A method of improvement of a subsoil under bored pile base by injection is presented. The method employs a special chamber attached to the reinforcement at the bottom of the drilled borehole. The chamber is made of semi-permeable textile bag. The injection entered under high pressure into the bag, causes prestressing of subsoil under the pile base. The results of load tests of piles improved in this manner have shown a substantial increase of their capacity together with simultaneous reduction of settlements. This technology has been implemented for four constructions such as trestle bridges in Gdynia and Warszawa and the bridges in Szczecin and Gdansk. The injection effects are shown based on the load test results.

Jan 1, 2002

By S. Chilka, I. Maloney, J. Brady

"The purpose of this project was to design the Electrical Service Platform (ESP) for the Cape Wind Offshore Wind Farm. The ESP structure comprises two primary parts: the topside platform housing the electrical equipment and the two jacket substructures providing foundation support to the platform. The topside is supported only by the two inner legs of each jacket. The site water depth is relatively shallow and the seabed comprised of loose sediment subject to severe local scour up to 18 feet. The piles are designed for local scour, storm conditions, vessel impact, ice loads and pile installation fatigue. This paper focuses on the design and construction aspect of this project.PROJECT DESCRIPTIONBackgroundThe Cape Wind project will be located in Nantucket Sound between Cape Cod on the Massachusetts mainland (northeastern coast of the USA) and the Islands of Martha’s Vineyard and Nantucket (Fig. 1). The project is to be sited on Horseshoe Shoal, about equal distances from the mainland and the two islands. The project will produce 75% of the electricity used on Cape Cod and the Islands of Martha’s Vineyard and Nantucket with zero pollution emissions and resulting in the reduced operations, fuel consumption and pollution emissions from the fossil fuel power plants in the region. The wind farm, if constructed per plan, is expected to be America’s first offshore wind farm.The wind farm will consist of an array of 130 Siemens 3.6-megawatt offshore wind turbines with a combined production capacity of 468-megawatts. The offshore wind turbine towers will be bolted onto the transition pieces supported by monopile foundations driven into seabed. The power from the 130 wind turbine generators will be delivered to the Electrical Service Platform (ESP) by an array of up to 14 seabed conductors."

Jan 1, 2017

By Arvindh Gupta

BC Hydro proposed to improve the stability of the existing Seven Mile Dam with 54 corrosion protected, re-stressable anchors comprising 92/0.6? strands each, in phase 2 of the program. Being globally the largest capacity anchors ever build, coupled with extra ordinary specifications, the project was a challenge for the entire post tensioning industry. The paper discusses the challenges associated with the anchor material supply as per specifications, extensive research and development carried out by Con-Tech Systems ltd. to overcome the challenges and contribute in making the project a success. The substance of this article is published in the Aug/Sep issue of ADSC magazine.

Jan 1, 2004

By Matt Sotirin

The Santa Fe train station and passenger rail platform were constructed in the downtown district of Fort Madison, Iowa, over a century ago. This landmark building and rail platform were in need of major renovations and rehabilitation in order to restore the site to a functioning railway train station. A multitude of key players from various public and private parties were involved in the design and construction of this project site. Part of the project consisted of constructing the passenger platform. The original design included helical piles to provide foundational support for the platform. Challenges occurred during construction due to the presence of an obstruction in the form of a poured concrete slab in the immediate area where the helical piles were to be installed. The contractor worked with the engineer of record and other consulting parties to value engineer the helical pile design and utilize self- drilling micropiles as a replacement to the specified helical pile system.

Oct 1, 2022

By Subhash B. Bhide

Deep foundations are affected by the presence of sulphates, chlorides, organic contents and water currents present in the soil. The sulphates in soil and ground water interfere first with setting of concrete. In long term, growing of sulphate crystals in concrete, crevices can spall the concrete. The chlorides mainly affect the steel. The organic content does not allow the concrete to set. It also reduces the compressive strength of concrete. The frequency and methods of sampling and testing for above corrosive elements are discussed. Presently available methods to avoid attack due to these corrosive elements are discussed. The stipulations by various codes are summarised. A method to assess the short term impact is elaborated with results of field studies. A tool developed to study the presence and effects of underground water currents on concrete is also discussed.

Jan 1, 1996

By Robert J. Carle

This paper reviews a variety of highway structures which have been built using steel sheet piling as the permanent structural elements of bridge piers, abutments and wingwalls. Those structures built over the past 20 years in Europe include major highway bridges over railroads, highways and waterways in both urban and rural locations. Most highway structures built in the United States using steel sheet piling have been limited to secondary roads in rural locations. The main thrust of this paper is the presentation of various design concepts for highway structures which utilize steel sheet piling. The main purpose is to challenge the profession to move forward from this conceptual presentation and to develop the details necessary to provide safe, cost-effective structures which go well beyond the scope of those being built in the United States today.

Jan 1, 1989