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By Mohammed Sakr

This paper presents the results of a full-scale axial compression and tension (uplift) testing program executed on large-capacity helical piles installed in very stiff to very hard clay till soils (i.e. cohesive soils). A total of ten tests including six axial compression tests and four tension (uplift) tests were carried out. The results of the axial compressive and tensile pile load tests and field monitoring of helical piles with either a single helix or double helix are presented in this paper. Helical piles are traditionally used to support light to medium loads (i.e. loads up to 500 kN or 56 tons). However the results of the present study confirmed that helical piles can support significantly higher axial compressive loads up to 2450 kN or 275 tons, which is about 5 times traditional design loads. The study also demonstrated the high tensile capacities of helical piles which was as high as 85% of their compressive capacity. Hence helical piles can provide a viable design option for foundations supporting relatively heavy loads.

Jan 1, 2012

By Deshmukh A. M.

Existence of human beings and their relationship with the nature is symbiotic. The lack of perspective and negligence of nature disturbs the equilibrium of environment and causes unprecedented disasters. Geotechnical engineers are directly concerned with hazards of nature as elements of foundation and of nature are inter related. Rational design and construction of foundation can be accomplished only after properly assessing influence of environment This paper briefly delineates impacts of environment and human activities and presents salient features of management of impacts through the system of deep foundation. Limitation of negative effects and enhancement of positive developments necessitates eco-consistent planning of engineering projects based on the geotechnical aspects of environmental impact management.

Jan 1, 1996

By Wolfgang G. Brunner

A 3800 m long temporary water-retaining dike has been constructed under extreme conditions in the harsh northern climate to enable two of the kimberiite pipes at the Diavik Diamond Project reserve to be mined using open pits. The Diavik Diamond Project is located on East Island at Lac de Gras in Canada's Northwest Territories, approximately 200 kilometres south of the Arctic Circle. The dike which has been constructed in up to 25 m deep water from crushed granite quarried from the site projects into Lac de Gras encircles the first two of the kimberiite pipes to be mined. An 800 mm wide diaphragm cut­off wall constructed of bentonite, cement and crushed rock, totalling 33,000 m2, and a two-phase jet grouted curtain wail at its base, totalling 8,400 m2, have been installed through the dike and underlying till foundation into bedrock. The cut-off is designed to minimise water seepage from Lac de Gras through the dike. In order to ensure that the dike had adequate internal stability and diaphragm wall construction could proceed safely, the crushed rock fill material dumped into the lake was first compacted by TR 75 deep vibrators. In 2000, Bauer Maschinen GmbH of Schrobenhausen, Germany were awarded the contract for the supply of all specialist foundation equipment required on site and for providing technical support to the Canadian main contractor Lac-de-Gras-Construction throughout the construction of the cut-off walls during 2001 and 2002. Installation of the cut-off walls was completed in July 2002, three weeks ahead of schedule, and dewatering of the inner dike areas commenced just 5 days later and has continued throughout August and September. After completion of extensive testing of the diamond recovery plant, the mine is scheduled to go into full open pit production in February 2003.

Jan 1, 2003

By Gerry Houlahan

The east span of the 3.5 km long SF-Oakland Bay Bridge is supported by different types of foundations along its span. Starting from the west, its first 460 m section comprising twin concrete box-girders is supported by sands and rock on Yerba Buena Island. A 620 m long steel suspension span then bridges a 25 m deep channel that is formed in sediments overlying rock. Twin concrete box girder structures, each 2.4 km long, complete the stretch over the remainder of San Francisco Bay to the engineered earth fill landing at its east end. For most of its length, the Skyway bridges water 3 to 10 m deep over soft surficial Young Bay Mud. The foundation types include spread footings with hold-downs, steel and concrete piles that are set in drilled rock sockets up to 3 m in diameter and 2.5 m diameter steel tubular piles driven to penetrations of up to 100 m. The design and construction-related considerations are presented. The different foundation types, influences of the site geology and earthquake demands on the substructures are discussed. The seismic motions of the bridge superstructures and substructures, as well as the depth-varying soil motions, influenced the foundation design. Together with performance-based design criteria, including post-earthquake footing displacement limits, these seismic demands influenced various aspects of the foundation design, including the use of battered and vertical piles.

Jan 1, 2005

By James V. Errico

On October 1, 1993 the regulations for assessing and cleaning up contaminated soil and groundwater in the Commonwealth of Massachusetts were revised. These new regulations, known as the Massachusetts Contingency Plan (MCP) 310 CMR 40.0000, were developed to keep routine releases out of the regulatory system and rely on private parties to handle most releases without Department of Environmental Protection (DEP) oversight. An integral part of the new MCP is the Licensed Site Professional (LSP). An LSP is required to handle activities and render opinions once a site enters the MCP. These regulations must be adhered to where ever a release has occurred, including construction sites. A brief overview of the new MCP is given below; see attached MCP Flowchart for graphical summary. Entering the MCP Process A release of oil or hazardous material (OHM) to the soil or groundwater above applicable reportable quantities (RQ's) or reportable concentrations (RC's) will require notification to the DEP and compliance with applicable provisions of the MCP. RQ's and RC's are listed in the MCP (310 CMR 40.1600) for most compounds that are typically encountered. For each compound there are two RC's for soil (S-1 and S-2) and two for groundwater (GW-1 and GW-2). The S-1 and GW-1 RC's apply to sites that are environmentally more sensitive, as a result they are lower than the S-2 and GW-2 RC's.

Jan 1, 1994

By J. Nakayama

For drilling large diameter holes for deep foundations, the common and distressing difficulty of long standing has been in coping with ground containing rocky formations and boulders. Where geological formation contains weathered rock or boulders, or deep rock socket is specified, drilling equipment occasionally is found to be unable to drill through and therefore will need supplementary equipment and procedures. Incentive of the MACH Drill Development has been to realize a capable drilling system for rocks of weathered to fresh rock without losing its applicability to usual overburden. Through seven decades' experience of manufacturing and operation of boring machines, the best features of all sorts of drillhead are known such as the drag bit, wing bit, auger bit, diamond bit, rock roller bit, down-the-hole hammer bit, etc.

Jan 1, 1988

By R. G. Horvath

The Statnamic loading test is a new and innovative method for testing deep foundations. The test is relatively inexpensive, quick, easily mobilized, provides for direct measurement of applied load and corresponding displacement, and is capable of very high loading capacities. The long duration of the applied loading, as compared to a dynamic loading test, allows for a straightforward determination of the static behaviour of the foundation tested. A new method of analysis of the Statnamic loading test, the Equilibrium Point Method, is presented. A description is given of the pile-soil model and a demonstration of how the static load-displacement behaviour of deep foundations may be predicted from the Statnamic loading test data. The Equilibrium Point Method of analysis is applied to three types of deep foundations in soils which respond differently to fast loading rates. These case histories, from Canada and the United States, include data from static loading tests for direct comparison, and demonstrate the ability of the Equilibrium Point Method to predict static behaviour of the deep foundations.

Jan 1, 1993

By Anuj K. Singh, Shuvranshu Rout, Manos De

"Foundation for tracks of coke transfer car and dust extraction pipe was designed as series of isolated foundations spaced at 11.0m along length of coke oven battery resting on soil at depth of 2.5m. In one region the foundations are close to adjacent 12m deep underground junction house. Five foundations in this zone were constructed on backfilled soil without proper compaction instead of engineering soil fill or concrete fill. The foundations settled under loads and the supported frame structure tilted after equipment erection and during trials endangering the safety of the structure and equipment operation. The distorted structure had to be rectified in-situ by arresting settlement. In order to stabilize the foundation and supported structure the supporting soil had to be strengthened in situ without any dismantling, reconstruction and adverse effect to equipment operation. This paper presents the case study on the evaluation of defects for the foundation failure and analysis of the problem, proposed rectification of the situation by appropriate soil stabilization scheme, monitoring of the stabilization operations and verification of effectiveness of the rectification work by measurement of settlements. The implemented solution has ensured safety of the structure and equipment without any adverse impact on normal operation.INTRODUCTION AND BACKGROUNDNew Coke Oven Battery was being installed for an integrated Steel Plant. The hot coke from oven is pushed out after completion of coking process through a coke transfer car onto a hot coke receiving car. The coke transfer car runs on rail track parallel to the line of ovens forming the coke oven battery. One rail is supported on the structure of the operating platform of the battery and the second rail rests on independent structure of track beams. A large diameter pipe for extraction of the dust emitted during coke pushing operation is also supported on the same structure that supports the track beams. The entire structure rests on columns spaced at approximately 11.0m along the length of the battery. The columns transfer load to ground through individual foundations resting on competent subsoil strata.Two sets of foundations for the rail track beam support and dust extraction pipe support are adjacent to deep underground junction house of coke carrying conveyor. The depth of the pit for the junction house is 12m. The layout and arrangement of the foundations in this region around the junction house (JH-1) is shown in the “Figs. 1a, 1b”."

Jan 1, 2017

By B. B. Broms

Embankment piles are common in the Scandinavian countries (Kjellman, 1940) and in Southeast Asia as support of fills, light structures, bridge abutments and deep excavations (Eide, 1968) as described in the following. Untreated timber piles are often used for light structures and shallow fills when the ground water level is high since they are inexpensive and readily available. When the applied loads are relatively high precast concrete piles and steel piles are preferred. DESIGN CONSIDERATIONS Embankment piles carry the load from a fill or a struc-ture either through skin friction along the sides of the piles (Fig. 1a) or through a precast concrete slab or through pile caps at the top of the piles (Fig. 1b). When the load is carried by skin friction it is often economical to use small diameter timber piles because of the large surface area (Asplund, 1939). For precast concrete or steel piles concrete caps are used to transfer the load to the piles due to the relatively high capacity of the piles since the skin friction resistance alone is not sufficient to transfer the load to the piles.

Jan 1, 2010

By Niels Krebs Ovesen

Close economic cooperation was established among the countries in western Europe during the seventies. As a consequence, among others, a need for harmonized technical specifications for civil engineering works arose. Technical specifications for design and execution of building and civil engineering structures exist in most of the European countries. In some countries such technical specifications are part of the building regulations and in other they are independent codes of practice and standards. The works on the Eurocodes was initiated by the Commission of the European Communities about 1976. The Eurocodes are intended as common unified design codes for different load bearing structures constructed from different materials. They are also intended to cover design of geotechnical structures. They are established with a view to promote the free movement of goods and services within the member states of the European Community - the so called Internal Market - and within the member countries of the European Free Trade Association, EFTA by removing obstacles arising from different rules for calculation and design.

Jan 1, 1994

By Dhanaji S. Chavan, Thallak G. Sitharam

"It is well known that sites comprising of saturated loose sand undergoes large deformations, due to liquefaction, during seismic shaking. To cope with this, different mitigation techniques such as vibroflotation, deep dynamic compaction, compaction grouting, deep soil mixing etc. have been used in practice. However, as all these methods are costly, a new mitigation technique is required. Air injection has emerged as a new mitigation technique in which air is injected into the saturated loose sand. The introduced air makes the pore fluid mixture compressible and results into decrease in the generation of excess pore water pressure during seismic shaking. This paper reviews the laboratory and field studies performed to investigate the effect of air injection on liquefaction resistance. In addition to this, previous research in the direction of desaturation has evolved different techniques to generate gas in saturated sand. These techniques have also been discussed in the present paper. All the field and laboratory studies have shown that even a slight decrease in the degree of saturation increases the liquefaction resistance significantly.Keywords: desaturation, air injection, liquefaction resistance, pore pressureINTRODUCTIONEarthquake events in the past, caused liquefaction of loose saturated sands at many sites in the world. The consequence of liquefaction varied from small deformations to catastrophic failures such as flow slides, lateral spreading, sand boiling etc. (Kramer, 1996). To reduce the liquefaction potential of such soils, different mitigation techniques have emerged across the world. Some of the most widely used mitigation techniques are vibroflotation, deep dynamic compaction, compaction grouting and deep soil mixing (Idriss and Boulanger, 2008).Yoshimi et al. (1989) found that the liquefaction resistance of partially saturated sand is significantly higher than that of saturated loose sand. Further, Pietruszczak et al. (2003) proposed desaturation of the saturated loose sand as a new liquefaction mitigation technique. It is observed that the liquefaction resistance of sandy soil is enhanced significantly owing to the desaturation caused during construction of sand compaction piles (Ishihara et al. 2003). Over past few years research is being carried out on desaturation of sandy soil and its liquefaction resistance ( Ishihara et al. 2003; Okamura and Soga 2006; Yegian et al. 2006; Yegian et al. 2007; Takemura et al. 2009; Eseller-bayat et al. 2013; He et al. 2013; Marasini and Okamura 2015; Zeybek and Madabhushi 2016). As a result of this, different techniques of desaturation have also emerged. Different studies conducted in this direction and their outcome has been discussed in the section to follow."

Jan 1, 2017

By Clyde Baker

Drilled shafts for many situations offer an economical alternative to driven piles. The Federal Highway Administration (FHWA) has spent considerable time and money in research and developing design and construction guidelines for drilled shafts. However, the full potential of the technology may not be realized because of the uncertainty of the effects of construction on the actual service behavior and the lack of either reliable quality control tests to check for or evaluate defects, or inexpensive load test procedures. Static load testing is very expensive and it is not feasible to load test each shaft on a project. Therefore, other means are necessary to confirm or evaluate the integrity of the completed drilled shaft or to determine the capacity of the completed shaft.

Jan 1, 1989

By Rüdiger Wunsch

The new high speed Vienna - St.Pölten line and the Lainzer tunnel are to be connected to the existing Western railway line in Vienna. This involves building an underground cut and cover branching tunnel which will be connected to the Western railway line by ramps. A key structure is the Herzmansky Street tunnel, which has a length of some 820m. It is to be constructed as a cut and cover tunnel using the top down method. The walls of the tunnel are designed as a water resistant structure consisting of double walls, an outer wall of bored piles and an inner reinforced concrete wall. The bored pile wall will be used as a temporary retaining wall during the construction phase and will also be a structural part of the per­manent tunnel wall. The retaining walls of the open pit, which will have a depth of up to 14m and a width of 12m, were investigated as a non-contiguous bored pile wall and overlapped bored pile wall. Preventing ground water from penetrating into the pit is of paramount importance. The high ground wa­ter level is the determining factor for the dimensioning of the bored pile wall and results in the require­ment for a water resistant concrete structure. It has been necessary to adopt adequate measures, therefore, in order to reduce the hydrostatic water pressure during the construction phase, assuming economical pile dimensions.

Jan 1, 2000

By F. Z. Suo

Baoahan Iron and Steel Complex is situated at lower beaches of the Yangtze River. The subsoils 50~70 M below the surface is a deposite of Yangtze River delta, consisting mainly of weak silty clay and loam, with low soil bearing capacity. Consequently, to build on such a weak soil a grant iron and steel integrated works weak soil improvement at the Complex, pile foundation is the effective type. It is estimated that at the first stage of Baoshan project 60,000 piles have been driven, of which 60% are steel pipe piles and 40% reinforced concrete piles. To provide reliable basis for pile foundation design, on-site loading tests were carried out for long reinforced concrete piles 27,45 60 M in length ,with strain gauges on the chief reinforcement of pile shaft and strain rod on pile tip. Based on loading tests, the paper discusses and analyses some issues, including determination of load transfer mechanism distribution of frictional resistance. Tests show that as far as long friction piles in soft clay are concerned, regardless of the properties of pile tip's bearing stratum, loads are mainly carried by shaft frictional resistance which it is effective to determine pile capacity in terms of P ~ S relationship.

Jan 1, 2010

By Christopher J. Pacitto

This paper presents a case history of an engineered, monitored, and tested program that provided an effective and satisfactory basis for the completion of pile foundations for Twin Dolphins 1 at La Peninsula Condominiums located in the Isles of Capri in southwest Florida, U.S.A. An 8-story building (withl-story parking underneath) along with recreational facilities (such as a swimming pool and tennis courts) had been planned for final construction. Following an evaluation of various foundation alternatives, a precast prestressed concrete (PPC) pile-supported system was selected. The building foundations were designed for pile capacities of 445kN (50 tons) and 890kN (100 tons) in compression and 133kN (15 tons) in uplift. A test pile program was performed to provide site-specific pile driving data, verify design assumptions, determine production pile lengths, and evaluate pile driving criteria. A total of 24, 356 mm (14-in.) square, 19.8 m (65 ft) PPC concrete piles were driven and dynamically load tested utilizing a Pile Driving Analyzer (PDA) within the building limits. Dynamic monitoring during probe pile installation and restriking was performed to estimate the ultimate capacity of the piles and to evaluate driving stresses during installation. CAPWAP analyses were preformed on PDA data to better estimate pile capacity, resistance distribution, and predict pile freeze (increase in pile resistance with time) and thus optimized the production pile lengths. Upon completion of probe pile installation, 12 of the probe piles were tested using the Pile Echo Tester (PET) function of the Pile Integrity Sonic Analyzer (PISA). PET testing was performed to evaluate the integrity of piles which had exhibited high driving stresses during PDA testing. Information gathered during the probe pile driving program was effectively utilized as part of the overall quality control program to install a total of 539 PPC piles (including 24 probe piles) within the building limits at the project site to depths ranging from 9.1 to 19.8 m (30 to 65 ft) below the existing ground elevation as part of the foundation support system. Prior to installation of probe or production piles, a termination criterion was established using 1-dimensional wave equation analyses in addition to the design pile embedment requirement. The predicted pile capacities compared very well with the capacities from the CAPWAP analysis for probe piles. Use of geotechnical instrumentation and PDA assisted technology enabled each foundation support element to be constructed to its optimum capacity and at optimum cost. Furthermore, by using PDA the consultant was able to quantify a difficult to measure geotechnical phenomenon termed "pile freeze" which eliminated costly overdriving and unnecessary splicing of piles.

Jan 1, 2002

Since the 1989 Loma Prieta Earthquake in the San Francisco Bay Area, the California Department of Transportation (CALTRANS) has accelerated seismic upgrading of their bridges. Many structures can be improved with the simple addition of hinge seat restrainers. Others require modification of column bents and superstructure to column connections. Often, footing retrofits are necessary, which require the addition of tension/compression elements (compression piling and tiedowns anchors) to resist overturning moments substantially larger than those originally used for footing design. These footing retrofits may include doweled reinforced concrete footing extensions or new pile caps which transmit forces to either driven steel or drilled concrete piles. In some cases, installation of these traditional piling elements is expensive, impractical or impossible due to: low overhead clearance, ground obstructions, high water table, noise or vibration sensitivity, or the inability to laterally expand the existing plan dimensions of the footing. In the latter case, one practical option is to attach small diameter drilled and grouted tension/compression piling elements (Pin Piles) to the existing footing. The footing may be strengthened with dowels and added concrete thickness or there may be a reduced shear span due to the installation of larger or jacketed columns. A reduction of elements is available with a Pin Pile alternative, particularly when the selection of traditional standard piles is governed by the reduced tension/uplift capacity available from the traditional elements, since Pin Piles exhibit superior uplift performance.

Jan 1, 1993

By Michael J. Brown

It is often necessary to undertake some form of pile testing to verify design calculations. Historically this has been limited to static and dynamic tests. Newer rapid testing methods such as Statnamic are seeing more frequent use. This form of testing can be advantageous due to short set up time and test duration. Although the methodology suffers from a lack of formalised guidance and may prove difficult to analyse in certain soil conditions. This paper investigates the suitability of Statnamic testing and analysis for a range of soil and pile types as well as different installation methods through a number of case studies undertaken in the UK. Recommendations are made on test specification and analysis.

Jan 1, 2006

By Radianto Elprama

For the realisation of the underground railway line RandstadRail in the city area of Rotterdam a bored tunnel is under construction. Diaphragm walls up to a depth of about 40 m were used to construct the building pits for the start shaft, the Blijdorp Station and the end shaft. The water tightness of the diaphragm walls was determined by leakage tests that were executed after the construction of the walls, but prior to the excavation of the building pits. The tests showed satisfactory results with a hydraulic resistance of the diaphragm walls of at least 500 days. To determine the water tightness of diaphragm walls it is recommended to follow the specific procedure as described in this paper.

Jan 1, 2006

By Ke Yang

Drilled shafts are widely used as foundation system for sound walls to resist lateral loads. The design method based on the ultimate lateral capacity, such as Broms method, is often used for sound wall foundation design. Allowable Stress Design (ASD) is currently used for deep foundation design. However, by October 2007, all states Department of Transportations are required to use the Load Resistance Factor Design (LRFD) approach for the design of foundation in highway projects. There is a need to develop a calibrated resistance factor in LRFD lateral design of drilled shafts supporting sound barrier walls. This paper provides resistance factors for design of laterally loaded drilled shafts supporting sound walls using Broms method based on the study using reliability based method and fitting to ASD method. Additionally, the resistance factors for static lateral load tests are recommended. Furthermore, a methodology to update the resistance factors using Bayesian approach by incorporating the on-site full-scale lateral load test results is presented. To illustrate the Bayesian update methodology, two lateral load tests in Colorado were employed to develop the updated resistance factors.

Jan 1, 2007

By Paul J. Axtell

Two new railroad bridges in Kansas City, Missouri are founded on drilled shafts embedded into the soil and underlying shale. The uncertainty arising from the non-homogeneous, anisotropic nature of most shales, and the variability of shales across the U.S., makes it a difficult material to assign appropriate design properties. As was the case on this project, the uncertainty of foundation performance in shale can lead to overly conservative designs, particularly with drilled shaft foundations. An extensive Statnamic axial testing program was performed to verify that the load-settlement behavior of the drilled shafts would be acceptable for the intended railroad traffic. Axial Statnamic testing was applied in three increasing cycles of 927 kips, 1007 kips, and 3177 kips, respectively. The maximum movements recorded at the shaft head during each of the loadings were 0.052 inches, 0.062 inches, and 0.257 inches, respectively. The loads applied in each of the respective Statnamic tests were not sufficient to reach the capacity of the shaft; so direct comparison of measured and calculated capacities is not possible. However, evaluation of the estimated design capacity can be accomplished based on results from the Statnamic testing program by utilizing normalized load transfer relations presented by O?Neill and Reese (1999). Such comparisons necessarily require extrapolation of the data measured in the Statnamic tests following typical load-displacement response. Results indicate the Kulhawy and Phoon (1993) method for estimating side resistance in Pleasanton shale rock sockets, assuming a smooth socket, appears to agree well with observed behavior during Statnamic testing. Accordingly, the O?Neill and Reese (1999) method for estimating the toe resistance in intermediate geomaterials, assuming cohesive rock with Rock Quality Designation (RQD) between 70 and 100, appears to agree well with observed behavior during Statnamic testing. Finally, based on Statnamic testing at varying load magnitudes and normalized curves developed by O?Neill and Reese (1999), the contribution of side resistance to the capacity of a deep foundation can be determined assuming no load is transferred to the base of the foundation during lower magnitude testing. Furthermore, higher magnitude testing can provide a means to evaluate the accuracy of design end bearing calculations.

Jan 1, 2006