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By Faisal Shalzad, Adnan Anwar Malik, Tadashi Maejima, Jiro Kuwano

Single helix screw piles carry most of the structural load through end-bearing if the helix is embedded in the dense bearing layer. The tip condition of the central shaft of the screw pile can be closed, closed with cutting blades, opened with flat cut, and opened with wedge shape cut and its selection is based on the insitu ground conditions. These different end conditions of the central shaft disturb the ground differently, leading to the change in bearing capacity. In this study, an attempt is made to investigate the effect of open and close-end screw piles on installation effort (installation load and torque) and bearing performance in the dense bearing layer. The model steel screw pile with a pile shaft diameter of 21.7 mm and helix diameter of 43 mm is used in this study. Test results show that the open-end screw pile required less installation effort than the close-end pile that penetrated the bearing layer by 1Dhwith an unplugged condition. Further, the open-end screw pile shows a higher bearing response than the close-end screw pile if it enters the bearing layer with an unplugged condition.

Oct 1, 2022

By Kenneth Gavin, Weichao Li, Paul Doherty

"The lateral load capacity is one of the most important issues to be considered in designing piles to resist berthing loads, ship impact forces and for monopiles used in the offshore wind sector. A number of semi-empirical design approaches are available to calculate the ultimate soil resistance and assumed soil reaction profile along the piles’ embedded depth. In order to investigate the response of monopiles to lateral loading, a series of field experiments were conducted on instrumented steel pipe piles. Two lateral loading tests were performed on model piles with a diameter, D, of 340 mm and embedded depth, Lem, of 2.2 m, giving a Lem/D ratio similar to those adopted in the offshore wind sector. The piles were driven into dense sand at the University College Dublin geotechnical test bed site in Ireland. 10 pairs of strain gauges were installed on each model pile along the embedded depth at 10 levels to capture the load transfer and bending moment within the piles. The deflection and rotation at the model pile head were measured by Linear Variable Differential Transformer (LVDT) and inclinometers. The tests results were used to perform a detailed evaluation of current design methods. In the final section, discussion on the determination of the ultimate lateral load capacity for monopile design was conducted. IntroductionA pile’s lateral load capacity is determined, for design purposes, by two conditions: 1) the ultimate lateral load, Fu, divided by an appropriate safety factor; and 2) the load according to the maximum lateral deflection that the support structures can sustain. In view of the first condition, design methods to calculate the ultimate load were developed for piles used in the offshore oil and gas sectors, which tend to be much more slender than monopiles used in the wind industry. The purpose of this study was to investigate whether these design methods provide reasonable estimates of ultimate capacity, for short rigid monopiles.The methods to determine the ultimate lateral load generally follow three steps: 1) determine the ultimate soil resistance, Pu, along the pile embedded depth; 2) adopt the most appropriate soil reaction profile, Pz, along the piles embedded depth when the pile subjected to the ultimate lateral load condition (four of the most popular ones are depicted in Figure. 1); and 3) ensure equilibrium of lateral forces (see Equation 1, symbols are listed at the end of the paper) acting on the pile and bending moments (see Equation 2) about a point in pile is employed to determine the ultimate lateral load."

Jan 1, 2015

By Thai Nguyen Ph. D

Dynamic Load Test (DLT) on driven piles has been performed routinely all over the world. In several recent projects, even 100% testing has become a norm where every single pile is dynamically load tested. In these cases, most piles are of uniform sections, making the field analysis (CASE method) straight forward. The CASE method, which has been used for the last 50 years, however, is only applicable to uniform piles to monitor pile driving stresses as well as pile capacities. Signal matching analysis can handle different configurations. However, the analysis used to require user inputs (i.e., non-automatic). Manual signal matching analysis, which can solve non-uniform solutions, traditionally takes hour(s) to complete for one blow. As such, the real-time pile driving stresses and resistances had traditionally been relying upon the CASE method, using typical range of CASE damping (JC). Until 2021, due to the lack of a rigorous instant signal matching analysis for non-uniform piles, no tool was available to help engineers evaluate non-uniform piles in real-time. An inexperienced field engineer may overlook this shortcoming when evaluating peak driving stresses. Furthermore, ultimate bearing resistances for non-uniform piles may require further evaluation to account for the non-uniformity of piles if relying on the CASE method. This paper highlights recent advances in instant Signal Matching Analysis on non-uniform piles, allowing field engineers to monitor stresses and resistances of non-uniform piles during driving.

Oct 1, 2022

By Takefumi Takuma, Hiroyuki Nishimura, Shigeru Kambe

"In order to achieve tubular pile driving with low noise and low vibration, the Press-in Piling Method has been adopted on many projects. The method utilizes reaction force derived primarily from previously driven piles to push in the next pile into ground. With attachments, the Press-in piling equipment can deal with hard soil as well as difficult site conditions. At West Toronto Diamond Rail Grade Separation Project in Toronto, Canada, the Press-in piling equipment drove more than 500 of 914 mm (36 inches) diameter tube piles in length of 12 to 25 meters (39 to 82 feet) to construct earth-retaining walls for railway grade separation. Myoshoji River Restoration Project in Tokyo, Japan drove some 600 of 1,000mm (39.4 inches) diameter tube pipe sections in length of 11 to 22 meters (36 to 72 feet) by the rotary Press-in piling equipment to increase the flood drainage capacity of an existing river in highly populated area of the city. Both projects exemplify the advantages of the method in urban settings.1. BACKGROUNDThe Press-in Piling Method was invented some forty years ago in Japan, where a very large number of construction projects were causing widespread construction pollution, especially by pile driving work in densely populated areas. The method has been providing solutions for piling projects which could not have been built otherwise due to the noise and vibration impact to the surrounding communities. The method can be used with various types of piles including sheet piles, tubular piles, concrete sheet piles and so on. With high pressure water jet and continuous flight auger attachments, the Press-in piling equipment can deal with dense sand, stiff clay, gravels, boulders and even soft rock without employing a different set of equipment."

Jan 1, 2015

By D. Vanni

Constructing new infrastructure in urban areas increasingly entails the use of sophisticated techniques for soil improvement in order to minimize surface disturbances in adjacent areas and damage to existing structures. In Naples, at the new Piazza Garibaldi subway station, TREVI built a 45 m deep shaft using a hydromill, and utilized soil freezing for the excavation of the four station's tunnels, fifty meter long, located approximately 30 meters below the water table. An innovative use of directional drilling was specially developed by TREVI to successfully complete this challenging job.

Jan 1, 2006

By Terrence R. Udland, Russell D. Call

"Honored with a DFI 2006 Special Recognition Award, the Four Bears Bridge was constructed across Lake Sakakawea and opened to traffi c in September 2005. The very large lake size and severe winter conditions required an effi cient foundation design capable of resisting extreme ice loading and able to be effi ciently constructed in waters up to 90' deep (27.4m).DESIGNING FOR EFFICIENCYLocated in a remote area of North Dakota, the Four Bears Bridge replacement was a major undertaking for the North Dakota Department of Transportation, with dual goals of providing a new structure that would endure a severe environment, while enhancing the natural beauty of the area. Competing bids would achieve the best price for the owner, challenging the design team to creatively solve the engineering challenges unique to the site. Foundations for North Dakota’s new Four Bears Bridge had to accommodate water level fl uctuations of up to 40 feet (12m), along with extreme ice loading and be effi cient in order to be the low cost solution at the time of bidding. All three major criteria were achieved through the use of an effi cient ‘fl oating’ lost precast concrete cofferdam founded on steel pipe piles, which allowed the contractor to achieve the project schedule. The result is an award-winning bridge that is contextually sensitive to the environment. The bridge aesthetics pay tribute to the Three Affi liated Tribes, the Mandan, Arikara and Hidatsa, who reside on the Fort Berthold Indian Reservation, adjacent to the bridge site.The original Four Bears Bridge was located over the Missouri River near Elbowoods, the native grounds of the Three Affi liated Tribes. Construction of the Garrison Dam in the early 1950’s created Lake Sakakawea, a fl ood control project on the Missouri River, and resulted in the area being fl ooded. The bridge, along with many tribal members, was relocated to a site near New Town. The bridge provides the primary crossing of Lake Sakakawea and is a critically important transportation element for the residents of the Fort Berthold Indian Reservation. The relocated bridge had become functionally obsolete and not replacing it would require a detour of 170 miles (274km). The North Dakota Department of Transportation determined that it should be replaced. In order to achieve the most effective solution, the North Dakota Department of Transportation selected a design team responsible for the creation of competing steel and concrete designs that were competitively bid. The design team was led by Kadrmas Lee & Jackson, with FIGG responsible for the concrete bridge design, while Lichtenstein Consulting and Kadrmas Lee & Jackson completed the alternate steel bridge design."

Jan 1, 2007

By W. L. Chong

For a project located in Docklands Victoria, a high-rise development was proposed where the geology comprised soils of various compositions and consistencies to approximately 50m deep before being underlain by a siltstone bedrock. Due to the structural loads and spatial constraints, the majority of the foundation piles were designed to be socketed into the siltstone. Key factors in selecting the Continuous Flight Auger (CFA) technique as an effective piling solution are explained. These factors included structural and geological considerations, piling rig capabilities, pile testing regime to verify load performance and integrity, the extensive suite of construction quality controls and instrumentation records required while also achieving an appropriate piling budget and program. This paper also described how these factors underpinned the design approach of the final piling scheme. Critical aspects considered during construction and post-construction quality and pile testing records required to meet and satisfy the strict project piling specifications are also presented. The project adopted what may be considered the “best practice” in deep CFA piling. To the author’s knowledge, this project achieved the record for the deepest CFA piles in Australia where multiple piles to 53.8m deep were constructed.

Nov 1, 2022

By Spencer Ness, Yazen Khasawneh, William Tjaden, Mohammad Nassim

The evaluation of long-term performance of the wind turbine structures is essential in lowering the Levelized Cost of Electricity (LCOE) from wind sources. The required maintenance of the wind turbine foundation during the design-life time of the wind turbine may result in escalated cost, if not properly evaluated during the planning and designing phases. The degradation of the foundation soils’ stiffness due to the accumulation small plastic strains resulting from normal and/or extreme operating cyclic loading may result in escalating the O&M cost. The foundation’s stiffness degradation will result in a shift of the wind turbine system natural frequency, which may result in amplifying the vibrations generated at the hub. The anticipated shift of the wind turbine system natural frequency during the design-life time should be investigated through numerical simulations of the anticipated dynamic loading utilizing soil constitutive models that are capable of capturing the foundation stiffness degradation due to the accumulation of such small plastic strains. This study presents the validation of an element model that will be used to evaluate the performance of existing and/or proposed constitutive model.

Oct 1, 2022

By Zhang Wengang, L. John Endicott

The properties of many geological materials are variable. This is especially true for variations in elevation of the top of rock profile, strength of weathered rock, and conductivity of rock masses. Often the site investigation stage is completed by site specific ground investigation utilizing boring, sampling, and testing. Statistically this is a sampling procedure, but the borings are often widely spaced, and ground conditions between borings are deduced by interpolation. Often budgets are a limiting restraint and the information that is obtained may be less than desired. Sampling and testing is often biased. If claims for unforeseen ground conditions are to be avoided, the properties of the ground should be adequately identified. This paper describes how data can be used to evaluate the subsurface top of rock profiles, and can give insight into representative, maximum, and minimum strengths, and variation in conductivity relating to inflow of water into excavations, that can assist in planning the works and also in resolution, or avoidance, of disputes about unforeseen ground conditions. INTRODUCTION The mechanical properties of the ground are naturally variable. The work of Geologists, Engineering Geologists and Geotechnical Engineers is fundamentally investigative. Frequently, budgets for ground investigation are squeezed, resulting in widely spaced boreholes, with conditions between them determined by interpolation. Profiling can be adopted but the measurement, such as seismic velocity, is used as an indirect means of computing in-situ profiles and mass properties. Often a lot of test data are generated on large projects or by many projects in the same vicinity. Published data enlarge the database for a given project, and databases can be interrogated to gain insight into different categories of ground. Integration with geological studies can then lead to more reliable characterization of the ground in terms of identifying the materials present, their extent and their range of properties. This paper focuses on properties of rocks that are generally required for ground engineering, namely the top of rock profile, the unconfined strength of rock materials, and the mass conductivity. Data are obtained from Granodiorite and Granite in Hong Kong, and from Granite and the Jurong Series of weakly metamorphosed sedimentary rocks in Singapore. All four rock types have been tropically weathered, resulting in widely varying top of rock profiles, material strengths and mass conductivity. With a wide range in values for these parameters, project specific ground investigation conducted within a limited budget may run the risk of falling short of obtaining sufficiently reliable data sets, resulting in risk that unforeseen ground conditions may be encountered.

Jan 1, 2019

By Emre Turk, Suat Gullu, Candan Gokceoglu, Ahmet Sirri, Asli Can

In this study, the ground improvement application applied under the live railway bridge's approach embankments in Sivas, Türkiye was investigated as a case study. The soil profile is mainly composed of orangish conglomerate, clay, silty sandy clay, and under claystone, and mudstone units in the study area. As a soil improvement method, the Deep Soil Mixing (DSM) technique based on the principle of simultaneous mixing the ground while injecting with the water-cement mix, was selected. The application of DSM columns is designed to be 45 degrees horizontal, in order to reach the deepest point of the soft clay units for better improvement against settlement. The core samples were taken from the DSM columns and the compressive strength tests were performed in the laboratory. The results were higher than the minimum designed values. It means that inclined DSM columns were applied successfully, and the excessive settlement problem was solved.

Oct 1, 2022

By Andreu J. Ferrero

Polyurethane and acrylate resins are routinely injected into soils to gain strength and control water flow. However, most published data regarding strength gain is derived from laboratory samples created under ideal conditions. This study endeavored to inject resins into full scale mock-ups that could then be excavated and tested to yield results comparable to actual field conditions. To achieve this goal, a large container was filled with a silty SAND (SM), as defined by the Unified Soil Classification System (USCS). The soil was moisture treated and compacted in lifts of 0.3m. PVC pipes installed in a diamond grid into the soil were used to inject polyurethane and acrylate resins. Dynamic cone penetrometer (DCP) tests were conducted on the polyurethane treated soils, the acrylate treated soils, and the baseline untreated soils in the container. Testing results will be correlated to SPTn and CBR values to evaluate increases in the soil strength parameters in the treated soils. Cored samples of polyurethane and acrylate treated soils will be tested in compression, shear, and triaxial. These laboratory test results will focus on material property gains for the treated soils, in comparison to standard values for similar soil types. Complete documentation of the soil type, compaction methods, injection methods, and testing performed have been documented and will be presented in the final paper.

By Samer Rabab’ah, John C. Niedzielski, Jason Valeria

The PHX Sky Train is an automated people mover system located at Phoenix Sky Harbor International Airport. Phase II of the PHX Sky Train includes the design of over 150 drilled shafts for support of four guideway abutments, 75 guideway piers and three proposed stations. The soil conditions in this area generally consist of alluvial Sand, Gravel and Cobbles (locally known as SGC) deposited by the nearby Salt River. The foundation system will support relatively high axial loads, lateral loads and moments due to the height of the elevated guideway above the ground surface, where it needs to pass over roadways, parking lots, an existing terminal, and other buildings. Deep foundation design involves designing drilled shafts within the SGC deposits, some of which extend below the long-term groundwater table. Such extreme design loading conditions, together with difficult ground conditions at the site, result in several challenges for the design and construction of the deep foundation system for the project. This paper will present the results of a drilled shaft load test program implemented to provide site-specific measurement of the axial and lateral performance of the project drilled shafts. The load testing program consisted of a bi-directional load cell axial load test and a lateral load test performed on an instrumented test shaft 84 inches in diameter. The development and execution of the load test program and analysis of the test results are discussed. Comparisons were developed between predicted load capacities of drilled shafts using different design methodologies and the load capacity measured from the load tests. The load test results showed that underestimation of the capacity is evident using conventional methodologies. The load testing program was important for verifying the performance of the drilled shaft foundations on the project and was used to reduce the size of the drilled shafts. INTRODUCTION The PHX Sky Train is a five-mile long automated people mover system situated at-grade and on an elevated guideway which connects terminals, parking facilities, a rental car center and the Valley Metro Light Rail system in Phoenix. The purpose of this automated train system is to provide a secondary transportation system within the airport to relieve roadway congestion, minimize wait times and travel times for passengers and provide climate-controlled waiting areas. Phase 1 opened to the public on April 8, 2013. Phase 1A opened on December 8, 2014.

Jan 1, 2019

By Kevin Baumgartner, Steven Babcock

A landfill in Phoenix, AZ reached capacity and was graded over in the 1970s. The property was subdivided into lots in 2007 to create a business park. However, the challenging site conditions caused by the underlaying landfill put into question the feasibility of typical deep foundation systems. Several different foundation systems were evaluated to support the proposed development. The considered systems were: drilled concrete shaft, driven piles, drilled micropiles and helical piles. Soil stability, landfill decomposition, method of installation, flexibility of design, anticipated material, and equipment costs were considered. A system of helical piles with concrete pile caps and grade beams was selected. To mitigate unknown obstructions, holes were drilled through the landfill debris at pile locations and then backfilled with screened granular material. The helical piles were installed through these backfilled holes and advanced to bear in competent native material below the landfill. This method allowed for minimal disturbance of the landfill materials and provided a strong and adaptable foundation. Additional advantages of helical piles on this site include minimal installation vibration, no grout or concrete in the deep foundation, and capacity verification for each pile via torque correlation. Two load tests were performed to verify the design.

Sep 8, 2021

By Richard E. Sylwester

Evaluating surface and subsurface conditions for marine foundations (bridges, causeways, terminals, etc.) is often done with a limited amount of data. Subsurface information for these projects is primarily acquired using traditional methods, such as boreholes, test pits or divers, which tend to be expensive and limited in the area of coverage. A number of geophysical methods, including precision bathymetry, sidescan sonar, and seismic reflection or subbottom profiling are extremely cost-effective and obtain significantly more data than can be acquired using traditional intrusive methods. These geophysical methods provide detailed surface images and continuous profiles of the subsurface stratigraphy. This information can be invaluable for selecting the best location for geotechnical boreholes and to map potential geohazards such as submarine slides and filled or open scour holes. Offshore investigations conducted for a proposed highway bridge (Knik Arm Bridge, Cook Inlet, AK), the retrofit of two existing bridge (Antioch and Dumbarton Bridges, CA) and a proposed cruise ship terminal (Ketchikan, AK) used a combination of geophysical methods to map water depth, detect and map debris on the seabed, map the thickness of unconsolidated sediment, determine the depth to bedrock and identify potential geohazards such as scour holes. The results of the geophysical investigations will be used to select locations for obtaining geotechnical borings, to extrapolate geologic information between existing or proposed boreholes, evaluate the potential depth of scour and design a pile support pier. Geotechnical engineers, offshore contractors and bridge designers are realizing the importance of the early use of offshore geophysics for (i) site characterization, (ii) to reduce the uncertainty of geotechnical conditions thus avoiding designs that may be overly conservative and thus more expensive and (iii) to assist in selecting locations for geotechnical borings.

May 11, 2007

By Babak Mamaqani, Pirooz Barar

The Moanalua trestle spanned over Moanalua Stream, Honolulu, HI and was designed to accommodate construction of five 10 feet diameter cast in drilled hole (CIDH) piers as a part of Honolulu Authority for Rapid Transportation (HART) project. Due to the proximity of piers to the existing bridge, the trestle was elevated 20 feet above grade. Stratigraphy of the site consisted of shallow depth of fill and 150 feet of loose to very loose recent alluvium (soft clay) underlain with stiff to hard old alluvium (stiff clay). CIDH casings were installed by a rotator or oscillator depending on the diameter of the piers. The challenge was to design the trestle, not only for heavy gravity loads, but also to resist significant lateral loads from rotator and oscillator with minimal deflection. Series of piles, called reaction piles, were integrated into the trestle at each CIDH pier location to provide adequate lateral support for the rotator/oscillator. Due to the lack of information regarding soil Young’s modulus (E), a methodology was developed to calibrate and calculate E with two methods. Extensive analyses using LPILE and finite element analysis program, PLAXIS, were performed to model reaction piles and calculate lateral deflection. PROJECT SPECIFICATIONS The Honolulu Rail Transit includes 20-mile route and 21 stations to be built from East Kapolei to Ala Moana Center, with $1.55 billion construction budget. The project is divided into two phases as shown in Fig. 1: Phase 1 which connects East Kapolei to Aloha Stadium with expected operation in late 2020, and Phase 2 which connects Aloha Stadium to Ala Moana Center with expected operation in 2025.

Jan 1, 2019

By Robert C. Simpson, Ghada S. Ellithy

"There are several methods for estimating the axial capacity of drilled shafts installed in coarse-grained soils. Most methods estimate the ultimate capacity for side friction and tip resistance. Design capacity is then calculated by applying a resistance factor to the ultimate capacity. In reality, however, ultimate resistance may not be mobilized except after a significant displacement that is not structurally tolerated in either compression or tension modes.A full- scale load test is the best way to obtain the load settlement curve for a drilled shaft, especially in soil formations where accurate estimation of soil frictional properties from a field investigation may be difficult. This paper presents the results of a static, axial, compressive bi-directional load test, using the Osterberg method (O-cell test). The test was designed so that the shaft above the O-cell would move up and the shaft below it would move down when loaded. At the start of the test the concrete around the O-cell is fractured generally on a plane near the bottom of the cell.The test was designed to validate the design capacity of drilled shafts embedded into the Vashon recessional outwash (Qvro), which is a glacially derived sediment consisting of thick deposits of cobbly sand and gravel relatively free of silt and clay found in the Seattle, WA area. The test shaft consisted of a 2.5- feet (0.75 m) diameter drilled shaft. The test shaft was installed to a depth of about 47 feet (14.3 m) into this formation. A maximum load of 437 kips (1.95 MN) was applied during the test, in each direction. The maximum load was attained at upward and downward displacements of less than 0.1 inch (2.5 mm), respectively.Although the load test did not yield ultimate values, the results are compared to the design assumptions using methods adopted in the FHWA and AASHTO guidelines, which verified the adequacy of the design assumptions. We conclude that more emphasis is needed in the prediction of the service loads and corresponding mobilized displacement that may lead to a more cost effective design. It is also clear that more testing to higher loads could lead to more efficient designs on specific projects and generally as data is added to the local knowledge base."

Jan 1, 2015

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

By Ihab Allam PE, Meeok Kim. PE. Ph. D

The wet weather equalization basin (EB) planned for Pacifica, CA is a 45 feet deep rectangular shaped underground water tank containing over 2.1 million gallons of water, and located only 500 feet away from the Pacific Ocean. The location and size of the water tank, and the geotechnical characteristics of the selected site presented many engineering and construction challenges. The engineering had to consider a structural system which can fit into the limited area of the site and yet need to meet the storage volume requirement. In addition, the system construction should meet the city’s tight budget and schedule.

By Josef K. Alter

Long-term performance and behavior of post-tensioned ground anchors subjected to axial cyclic loading constitutes an important aspect of the stability, reliability and overall performance of wind turbine deep foundations. Axial cyclic loading of post-tensioned (PT) ground anchors in soils has not been thoroughly investigated as evidenced by the research conducted for this topic. This paper evaluates research test data, available literature, and industry expert opinion on the current status and problems of deep foundation post-tensioned ground anchor (PTGA) technology, as applicable to the wind energy industry. It also introduces a proposed design solution that addresses the problems of construction cost and long-term performance of wind turbine deep foundations in soils subjected to dynamic cyclic axial loading. Deep foundations using ground anchors for wind turbines have only recently gained attention as a possible viable alternative to the mass spread footings currently in use. One of the primary problems with general acceptance of current PTGA designs is the need for long-term anchor maintenance. The research that was conducted for this study indicates that current literature only partially addresses the many factors influencing load capacity and pullout performance of ground anchors. The lack of information indicates the deep foundation industry has fallen behind in designing and implementing new technology to improve safety and performance, ensure sustainability, reduce costs, and address environmental responsibility. This paper describes the significance of this problem as it applies to the wind energy market, and proposes a new technology solution. The research, expert opinion, and analysis presented by the author is used to support the premise that ground anchor construction cost and long-term maintenance can be reduced with PTGA systems using the Con-Tech Systems (CTS) patent-pending Groutable Void Form (GVF) technology.

Jan 1, 2010

By N. V. Nayak

Konkan Railway Project is one of the most ambitious railway construction projects in India, involving construction of a 760.km long, Broad Gauge (1676 mm), single track railway line, connecting Roha in Maharashtra State with Mangalore in Kamataka State. The railway line travels along the Western Coast of Indian subcontinent, through states of Maharashtra (382 km), Goa (105 km) and Karnataka (273 km) (Fig.1). The project alignment traverses through one of the most formidable terrains ever encountered, in the history of railway construction in India. In the State of Goa only, railway alignment is crossing 6 major rivers Terekhol, Chapora, Mandovi, Zuari, Sal and Talpona. Zuari Railway Bridge (1305.6 m), Mandovi Railway Bridges (I and II) (1182.7 m) rank as 2nd and 3rd long bridges, (first longest bridge being Sharavati Bridge (2.2 km} at Honavar) which have been constructed on Konkan Railway. All these three bridges have been constructed by M/s.Asia Foundations and Constructions Ltd. (AFCONS). This paper presents, case history of construction of pile/caisson foundations for Zuari and Mandovi Bridges.

Jan 1, 1996