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By Waddah Akili

At an offshore site along the Red Sea coast of Saudi Arabia, marine structures were supported on tubular steel piles driven into coral and coral contaminated sands and silts. Surprises and disappointments faced during the installation of the piled foundation were, to a large measure, due to inappropriate design methodology and absence of proper soil information. The paper describes the design evolution process, highlights the static pile test program conducted to verify design parameters, and amplifies the need to prepare for worst possible scenario when coral deposits are encountered. Despite corrections made to the design, based on site-specific insitu parameters (skin friction, end bearing) perceived from load tests conducted on site; the final design adopted overestimated capacities in over 50 percent of total piles driven. The paper describes the changes introduced to the design during the execution of the project, highlights the pile test program conducted to verify the design, and compares pile design penetration with actual penetration depth. The unpredictable and erratic pile behavior observed, ascertains the need for more appropriate pile design and installation guidelines for driven piles in coral and coral contaminated formations.

By Tomohiro Yamasaki

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

Jan 1, 2015

By Martin B. Hudson, Andrew K. Cho, Rolff B. Knobel, Les R. Chernauskas, Jonathan L. Ernst

ABSTRACT The Bruce Museum, located in Greenwich, Connecticut, is home to an extensive display of art and natural history exhibitions. A large addition was designed to be constructed adjacent to the museum requiring new spread footings to be installed up to 16.5 feet below the existing foundations. The soil conditions at the site consist of highly variable sand and gravel overlying weathered rock and sound bedrock. The Contract Documents called for traditional foundation underpinning. Traditional underpinning techniques, however, presented two major challenges on this Project; (1) deep underpinning pits would be required involving multiple levels and staging with tieback support and (2) the highly variable soil and bedrock composition and elevations presented uncertainty in the design and construction of the pits. In lieu of traditional underpinning, Geosciences Testing and Research, Inc. (GTR) proposed an “active” soil nail underpinning system. A major reason that the soil nail underpinning option was feasible, related to the fact that the soil nails and facing could be installed slightly in front of the existing footings rather than directly underneath the existing footings. The soil nail wall design involved one to four rows of soil nails with nail positions and wall depth able to be adjusted “on the fly” as excavation progressed depending on the field conditions encountered. To create the “active system,” the soil nails were pre-loaded to mitigate wall deformations that would be associated with a standard passive soil nail wall design. To evaluate the performance of the active soil nail wall and confirm design assumptions, an extensive automated monitoring, on-site testing and inspection program was proposed and executed by GTR to monitor deformations of the wall and the museum in real-time, evaluate and confirm bedrock and soil bond stresses and ensure that each soil nail was pre-loaded and locked off. Careful analysis, planning, and use of the observational method illustrates the importance of collaboration between design and construction personnel and applying engineering judgement throughout construction. The use of the observational method includes the potential for modifying design based on conditions observed. This paper presents a unique case study of the “active” soil nail underpinning system to support and protect sensitive structures, close collaboration between design and construction facilitated by real-time deformation monitoring, and its successful application as a safe and cost-effective alternative to traditional underpinning.

Oct 1, 2022

By Stefano Pirrello

"Sydney’s booming real estate market has pushed property developers to invest in historically “no-go” areas, which were previously too expensive to develop. These areas are usually near rivers where the sites are underlain by deep alluvial and estuarine sediments. In these ground conditions conventional bored pile techniques are often not competitive. Contiguous Flight Auger (CFA) and Drilled Displacement Piles (DD) techniques are on the other hand suitable for these ground conditions. This paper deals with the design and construction challenges encountered with these piling techniques for a series of high-rise towers in Sydney’s West. The advantages of DD over CFA piles such as reduced overall spoil with substantial cost savings and achievable rock sockets in medium strength bedrock are discussed. Design validation through interpretation of real-time data from the piling rigs’ on-board computer data, and low and high strain pile dynamic testing (PDA) is discussed. Testing data is presented as CAPWAP (Case Pile Wave Analysis Program) analyses for different concrete grades.INTRODUCTIONThe booming real estate market in Sydney has pushed property developers in investing in historically “no-go” areas, which were previously too expensive to develop. These areas are usually near rivers where the sites are underlain by deep alluvial and estuarine sediments. In these ground conditions conventional bored pile techniques are often not competitive. Contiguous Flight Auger (CFA) and Drilled Displacement (DD) Pile techniques are on the other hand suitable for these ground conditions and were utilised using concrete injection methods. This paper deals with the design and construction challenges encountered with these piling techniques for a series of high-rise towers in Sydney’s West.GEOLOGY & GEOTECHNICAL CHARACTERIZATION OF THE SITEThe Sydney 1:100 000 Geological Series Sheet shows that the site is underlain by man-placed filling and alluvial/estuarine sediment. The sediment comprises silty to peaty sand, silt and clay. Shell layers are also expected to be present within the soil profile. The Prospect/Parramatta River 1:2500 Acid Sulphate Soil Risk Map shows the site as ‘Disturbed Terrain’ in which soil investigations are required to assess acid sulphate soil potential. Several Cone Penetration Tests and Boreholes were carried out during the geotechnical investigation. All boreholes were extended to bedrock and NMLC-sized diamond core drilling was used to obtain 50mm continuous core of the rock, enabling unconfined compression strength testing to be carried out on selected samples. A summary of the ground conditions encountered on this site and inferred from the CPTs can be described as follows:"

Jan 1, 1900

By Nihal Bohra

A temporary bridge, supported on steel pipe piles, was built to expedite the construction of a breakwater structure off the western coast of Peru. The bridge provided access for dump trucks to the breakwater across a 342 m (1122 ft.) wide navigation channel from a liquefied natural gas (LNG) loading facility, at the end of a 1.3 km (0.82 miles) long permanent trestle, in 15 m (50 ft.) water depth. After the completion of the breakwater, the temporary bridge was removed, and the piles were extracted approximately one year after the initial driving. The bridge deck was typically supported on pairs of 914.4 mm (3 ft.) diameter, 18 mm (0.708 inch) wall steel pipe piles spaced at 7.5 m (24.6 ft.) across the bridge width and 18 m (60 ft.) along the bridge length. In an attempt to reduce the driven pile embedment, an inner closure plate was installed at 2.7 to 7 m (9 to 23 ft.) from the pile toe to force closed-end behavior. The piles were designed to carry 3400 kN (383 tons) axial compression load, and a minimum of 8 m (26 ft.) embedment was specified to provide sufficient resistance to the lateral loads. The subsurface conditions consisted of cemented conglomerate of sand, gravel, pebbles and some boulders, locally known as the Cañete Formation. The driven pile embedment varied widely, between 8 to 24 m (26 to 79 ft.). A significant portion of each pile was above the seabed, passing through seawater and up to the bridge deck, and was therefore unsupported. The extraction of the piles was challenging due to the subsurface conditions, presence of significant water column, pile weight, and the inner closure plate. Several different approaches were attempted before the piles could be successfully extracted. This paper summarizes the difficulties encountered and observations made during the driving and extraction of these piles.

By Gisele R. Passalacqua, Aly Mohammad, Joanna Smith

The $13 billion John F. Kennedy (JFK) airport construction redevelopment program includes new terminals and buildings that are supported on piles to meet the airport expansion demand due to increased travel. This paper presents a case history for JFK airport with main focus on construction activities and lessons learned. Challenges include limited head room, presence of underground utilities, and hard driving. Video inspection of pile proved very beneficial. In general, soil conditions at JFK Airport consists of sandy fill followed by a 5-foot thick organic soft layer. Below the organic layer, glacial sands occasionally mixed with gravel were encountered for great depth with increases in density with depth. The tapertube pile is an ideal choice for foundations with high capacity achieved through skin friction along the taper section. The piles are easy to splice to accommodate low head room. Pile Driving Analyzers (PDA), and Static Compression Load Tests were performed. The results of these tests are presented in this paper to illustrate the high pile capacity achieved. More detailed discussion and analysis of the test results will be presented in another paper related to the same project. Lessons learned from this project are shared to help the engineering community with future design and construction of similar projects.

By Richard Guenther

As available space in urban centers becomes more scarce, builders and developers are increasingly turning to vacant, existing structures to meet cities' growing needs. The developers of City Ridge Roadside Development and North America Sekisui House (NASH) - - found a suitable site for their "urban village" at the former Fannie Mae headquarters complex on Wisconsin Ave. NW in Washington, D.C., which had been vacated in early 2018. The urban village will consist of eight new structures centered around the building that currently sits on the site. All told, the project will include 687 residential units, a 150-room hotel, over 150,000 sq ft (13,935 sq m) of retail space, and 62,000 sq ft (5,760 sq m) of office space. A below-grade parking structure will extend across most of the footprint. The Fannie Mae building, which was designed in the Colonial Revival style to mimic the Governor's Palace in Williamsburg, Virginia, was named a historical landmark following a request from the development team. The central portion of its existing masonry structure was built in 1956 on pile caps with small-diameter cast-in-place piles. Two wings, which were added in 1962, were built on belled caissons. There are three levels above grade and one below.

Feb 1, 2022

By Shahriar Vahdani, Andy Herlache, Andrew Bro, Wei-Yu Chen

"The Presidio Parkway Project will reconstruct approximately 1.6 miles of highway, including seven bridges, three cut-and-cover tunnels, and an undercrossing connecting the Golden Gate Bridge to the City of San Francisco, California. The project site is approximately 5.6 miles from the San Andreas Fault, which is capable of producing magnitude 8 earthquakes. Seismic hazards include strong ground shaking, soil liquefaction, ground settlement, and lateral spreading. At the Tennessee Hollow bridge section up to 30 feet of loose sands and soft clays are present. Concerns are raised that standalone drilled piers will experience excessive lateral soil loads from liquefaction-induced lateral spreading pressure resulting in excessive pier head displacement of up to 8 inches. Ground improvement by Cement Deep Soil Mixing (CDSM) is proposed to provide additional foundation stiffness. This paper presents the methodology to: 1) assess the effectiveness of the ground improvement in resisting lateral spreading, and 2) optimize ground improvement design at individual bridge bents based on local site condition. A series of 3-D numerical analyses are conducted and the results show that drilled piers with CDSM ground improvement are capable of withstanding seismic demands from lateral spreading and the lateral pier head displacement is reduced to less than 2 inches. The adopted analytical approach is efficient at modifying design for individual bents and can be considered for future pier foundation design in seismically active areas. IntroductionThe Tennessee Hollow bridge section (Low Viaduct) is an integral component of the Presidio Parkway project which will replace the existing facility with a new multi-lane roadway between the Golden Gate Bridge and the City of San Francisco. As shown on Figure 1, the project site is located about 5.6 miles east of the San Andreas Fault and 12.5 miles west of the Hayward Fault. The Low Viaduct will span over a future wetland habitat subject to tidal fluctuations and potential scouring."

Jan 1, 2014

By Andrew J. Ciancia

The construction of the Pennsylvania Station in Manhattan, the Beaux-Arts masterpiece, was completed in 1910. In financial ruin, the Pennsylvania Railroad Company sold the station in the 1960?s and the new Madison Square Garden and the Penn Plaza complex were constructed at the site. The demolition of Pennsylvania Station brought public awareness and outcry to protect historic structures and the Landmarks Preservation Commission (LPC) was subsequently established in 1965. In the 1960?s relatively little engineering data was available on the performance of historic structures during adjacent construction and thus, no published criteria were established by the LPC on allowable movements and vibrations. During the late 1970?s a commercial tower was planned adjacent to the landmark Fraunces Tavern Block (FTB) in lower Manhattan. Through negotiations between the LPC and the developer, Dr. M. I. Esrig and the author were retained to monitor the historic block during foundation construction. The monitoring data and building performance compiled from the project formed the basis of the published 1981 ASCE technical paper by Esrig and Ciancia entitled ?The Avoidance of Damage to Historic Structures Resulting from Adjacent Construction?. Based on the ASCE paper, the NYC Department of Buildings adopted Technical Policy and Procedure Notice #10/88 entitled ?Procedures for the Avoidance of Damage to Historic Structures Resulting from Adjacent Construction When Subject to Controlled Inspection by Section 27-724 and for Any Existing Structure Designated by the Commissioner?, June 1988. This paper describes the author?s recent experience during the installation of deep foundations within, or adjacent to, three Manhattan landmark structures. Discussions are provided on the foundation construction, monitoring programs and performances of the three structures.

Jan 1, 2008

By Xiaocen Lu, Guowei Li, Jiantao Wu, Thang N. Nguyen, Andrew C. Amenuvor

"This paper investigates the effect of driving a group of 52 open-ended Prestressed High Strength Concrete (PHC) piles on an existing highway embankment based on field measurements of excess pore pressure and lateral soil displacement. Excess pore pressure due to pile driving increased with depth and decreased with increasing distance from the pile, influencing a distance of 43 pile diameters. For pile groups, the rate of dissipation of excess pore pressure decreased with increasing depth and averaged 79% in 20 days, during which maximum ultimate bearing capacity was not yet attained. Lateral soil displacement continued to increase for a period of time after the end of pile driving and this could have resulted in significant inclination of piles if pile installation was too quick and pile spacing was too small. Lateral soil displacement due to pile group decreased with decreasing distance to the existing embankment as a result of high soil density produced by the embankment loading. The results also indicate that the effect of pile group installation on the existing embankment is negligible.INTRODUCTIONPile driving can cause excessive lateral displacement of soil and heaving of the ground surface, which may adversely affect nearby structures. In addition, lateral deformation and excess pore water pressure resulting from pile driving can exert lateral pressures and vertical forces on the piles, and impact negatively on the project and its surroundings. Therefore, it is important to evaluate the influence of pile driving on the nearby structures as well as the project itself when expansion works are carried out.Recent years have seen some development in the application of field tests for studying soil disturbance due to piles, and these tests usually involves pore water pressure and lateral soil displacement monitoring during pile driving. Results of field experiments performed by Reese and Seed (1957) in San Francisco Bay Mud with instrumented piles showed that pile installation generated large pore water pressures at the pile surface, with only slight increase at a distance of 15 pile diameters away. The measurements indicated that the increase in pore water pressures can exceed the initial total overburden pressure. Holtz and Lowitz (1965) reported a decrease in undrained shear strength immediately after pile installation, which was largely recovered after full pore pressure dissipation for field measurements within 1.5–2 pile diameters from the pile surface. Hwang et al. (2001) presented results of large scale pile driving tests where maximum excess pore water pressure generated decreased rapidly with increasing distance from pile. The excess pore water pressure became negligible at 15 pile diameters from the pile. Their results also showed that lateral displacement of the ground decreased with increasing distance from the pile. Pestana et al. (2002) carried out full-scale closed ended pile tests in the Young Bay Mud deposit. Higher excess pore pressures were observed for points closer to the pile, which decreased with increasing distance from the pile wall. Exponential decay of excess pore pressure with time was also noted. An 80% dissipation of excess pore pressure was achieved for soils more than one pile diameter away from the pile wall between 50 to 80 days. Lateral deformation generally decreased with increasing distance from pile wall, whilst varying erratically with depth. Bozozuk et al. (1978) reported on soil disturbance due to driving of 116 concrete piles in sensitive marine clays in a construction project. Maximum pore water pressures after pile driving within the group, and 6m (20 pile diameters) from the group were over 35-40% of the total overburden pressures, and the influence of pile driving on pore water pressure at 20m away from the group was very small. Cooke and Price (1973) studied a 168-mm-diameter instrumented pile jacked into over consolidated London clay. Outward lateral displacements ranging"

Jan 1, 2016

By Athena C. Denivo, Pablo V. Lopez, Sissy Nikolaou, Alfred H. Brand, Ahmad Rahimian, Rudivien G. Josef

"The United States Tennis Association (USTA) Billie Jean King National Tennis Center (BJKNTC) site is located in the northeastern portion of the Flushing Meadows Corona Park area of Queens, N.Y. The site occupies some of the most difficult subsurface conditions for construction in the New York City (NYC) metropolitan area, with unique challenges from geotechnical, seismic and foundation design perspectives.At the USTA site, Paleozoic crystalline bedrock is found at a depth of roughly 300 to 400 ft (90 to 120 m) below grade. The geologic history of the site is complicated, starting from the early Pleistocene, when the ancient Hudson River temporarily changed course, flowing across Queens enroute to the Atlantic. It eventually carved a deep valley through the Cretaceous soils, in some places all the way down to bedrock. A series of glaciers advanced and retreated across the region during the Pleistocene times, filling the deep valley with layers of assorted glacial soils. At its southern edge, the last major glacier to flow across the region built up a ridge at the southern tip of Flushing Meadows known as the Harbor Hill terminal moraine. This ridge blocked the valley forming a dam, so as ice started melting away the valley filled up with a lake fed by glacial meltwater. Layers of clean outwash sand and varved silt and clay filled the glacial lake. The ice did not retreat in a steady manner, instead periodically readvancing over the previously deposited soil in the lake, then retreating far enough to let the lake drain temporarily into Long Island Sound, before readvancing again.As a result of this repeated sequence of retreat, advance, retreat, etc., there are places where a “crust” of desiccated soil formed when the lake drained, and areas with interlayers of outwash sand where ice readvanced into the lake. When the ice melted north of Long Island Sound, the glacial lake filling Flushing Meadows drained forming Flushing Creek. During the Holocene (roughly the last 11,000 years), as ice melted further away and sea-level rose, low lying areas filled with river sands and marine clays, along with coastal marsh deposits. Table 1 lists the soil design properties on site and Figure 1 exhibits the geologic section across the site."

Jan 1, 2015

By Kazuyoshi Kamimura, Masaya Kawata

"It has been 30 years since the cement deep mixing (CDM) method developed in Japan. CDM method has been applied to many structures. While various technical improvements have been implemented in the meantime, the single-axial and double-axial technologies used at the time of its initial development are still prevalent.In response to the recent trend of reducing construction costs, we developed a triple-axial CDM method called the “Lemni 2/3 Method.” This method uses two lemniscate motions caused by newly developed auxiliary stirring devices and employs a double-axial injection method in which the cement slurry injection takes place only from the outer two axes. In this way, it is possible to create a stabilized body around the three axes. Moreover, this method does not require substantial equipment investment as conventional construction machine and facilities can be used without modification and large volume work is possible.With these technologies, this method can achieve a substantial reduction in the construction period and cost, while ensuring the same level of improvement quality as conventional methods. As a result, this method is being applied to ground improvement work in a variety of places.Lemni 2/3 Method was first put to practical use in 2004. Since then, the method has been used for ten projects. In this paper, we show some application examples of this method.OUTLINE OF TRIPLE-AXIAL CDM METHOD (LEMNI 2/3 METHOD)In the newly developed CDM method (Lemni 2/3 Method), work efficiency is improved by employing triple-axial stirring blades instead of the conventional single- or double-axial type. Existing conventional construction facilities for double-axial type can be used with only minor equipment additions, because the cement slurry injection takes place only from the outer two axes.Construction Machine and Construction MethodThe combination of major construction machines of the Lemni 2/3 Method differs little from the standard specifications of the double-axial type as shown in Fig. 1. Existing work control equipment can be used without modification, which is further evidence of the simplicity, convenience, and economy of the new method. The Fig. 2 photo shows a full view of the construction machine, and the Fig. 3 photo shows the stirring blades and the auxiliary stirring devices. The work procedure for the Lemni 2/3 Method is shown in Fig. 4."

Jan 1, 2015

By Sam Warren, Antonio Marinucci, Genesis Z. Figueroa, Anne Lemnitzer

Drilled Displacement Piles (DDP) provide an ideal deep foundation solution that combines the benefits of ground improvement with traditional advantages of piling systems. This paper consolidates data from 20 construction projects in which more than 30 DDPs were installed and tested axially. High quality site exploration data (e.g., Cone Penetration Test and Standard Penetration Test) were evaluated to derive geotechnical analysis parameters. The test sites consisted of mostly mixed soil types with strongly stratified layers of sand, silt, and clay. Pile diameters ranged between 40 cm and 61 cm. Test results were compared with predictive methods developed specifically for DDPs as well as methods used in general geotechnical practice. The accuracy of the empirical methods is presented in terms of total pile capacity, pile length/diameter, and soil type. The large majority of all examined methods underpredict the in-situ pile capacities. It was also found that the difference between the tested and predicted capacity is strongly related to the level of improvement in the surrounding soil due to the piles’ installation. A general comparison between predictive axial accuracy and the observed level of ground improvement upon installation is also discussed.

May 1, 2022

By Jeffrey Goodwin P. E., Melih Demirkan Ph. D. P. E., Kevin Tehansky P. E.

Just an hour drive down MD 301 from National Harbor, construction to replace the Governor Harry W. Nice Memorial/Senator Thomas ‘Mac’ Middleton Bridge (HNB) began in spring of 2020. The Maryland Transportation Authority (MDTA) contracted with Skanska-Corman-McLean (SCM) to deliver a new US 301 bridge spanning 1.9 miles from Maryland to Virginia over the Potomac River aiming to improve capacity, safety, and access of the roadway. The project area presented a geotechnical design challenge due to the installation of new bridge foundations in the problematic soils of the Atlantic Coastal Plain alluvial deposits. With the existing bridge remaining in service during construction, and the site’s logistical constraints placing new pile driving operations near existing abutments and piers, a complex instrumentation and monitoring plan was developed to ensure public safety throughout the project. This paper discusses the geological conditions of the project area, the collaborative approach of various design team members to develop an appropriate monitoring plan utilizing various instrumentation, an understanding of baseline conditional movements of the existing bridge, and impact response of adjacent construction activity to help deliver effective new bridge foundations while protecting the old ones.

Oct 1, 2022

It is my great pleasure as mayor of the city of Amsterdam to welcome you today to Amsterdam, and to the 10th International Conference on Piling and Deep Foundations. The history of Amsterdam has been connected intimately with your professions of geo-engineering and geotechnology, since its very first days. It is good to be aware that you are part of a very old tradition. The knowledge that we need today to build and renew the city has been gathered over a century long process so that we fortunately can stand on the shoulders of the giants before us. During the centuries people living in this part of the Netherlands have always struggled against the water. The same waters that brought the opportunity for a seafaring country to discover the world and to build an empire in the 17th century were a threat to the low lying Netherlands.

Jan 1, 2006

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 Andrea Gambi, Giancarlo Olivucci, Maurizio Lenzi

"In the paper a criterion for the evaluation of the sharing of the lateral loads in a piled foundation is presented. It relies on the the compatibility condition between the rotation of the rigid pile cap and the rotations of the pile heads, following in that the criterion suggested by the Eurocode 8 - Part 5. This assumption leads to an analytical solutions which allows to deal with the sharing of the lateral loads and moments by means of two main interaction parameters only. A sharing domain is also derived and it shows the role played by the eccentricity of the lateral load on the values of the axial forces and of the bending moments at the head of the piles.INTRODUCTIONIt is well known that the interaction among soil, piles and foundation is one of the most complex subject to deal with in Geotechnical Engineering. Its rigorous study needs to employ suitable finite element software nowadays available and able to take into account the non linear behavior of the soil as a continuum and the inelastic response of the structure. A deep insight to the topic of the sharing of the loads cannot obviously renounce to this approach.On the other hand it is a daily need of the designers to have at their disposal simple tools that allow to make preliminary evaluations of the basic equilibrium conditions. To this purpose many methods of analysis have been developed in the past to face the sharing of the loads in a simplified version. The present contribution follows this way trying however to introduce some improvements that leads to find a solution that satisfies both the equilibrium of the forces and the compatibility of the movements (Lenzi, Gambi, Olivucci, 2002). The proposed model allows to identify the basic parameters which govern the sharing of the lateral load and it allows to perform also parametric analysis and quick checks that may be useful in the design of the piles."

Jan 1, 2005

By Ambarish Ghosh, Chitralekha Ghatak, Tanumaya Mitra, Tarun Sengupta, Sajib Das, Sankar Kumar Nath

"Currently construction of important structures like bridges, flyovers and high rise buildings in and around Kolkata are in full swing. These structures have mostly pile or well foundations. The design methodology and construction techniques are being employed keeping in view both the safety and economy of the project. The data presented in this investigation have been taken from Geotechnical Investigation report of Component B in connection with construction of Extradosed Cable Stayed Bridge over River Hooghly in Hooghly and Nadia district of West Bengal, India. The investigation site is located within close proximity of Eocene Hinge Zone which is being taken as the principal contributor of Earthquakes in and around Kolkata. Considering the importance of the project detailed and exhaustive geotechnical investigation has been carried out and site specific response spectra have been generated for analysis and design of the bridge. This paper presents site specific response spectra, liquefaction analysis and comparison of lateral load carrying capacity of pile using Winkler approach and IS 2911 guidelines.INTRODUCTIONPile foundations are used to transfer the load of the super structure through soft soil deposit to deeper bearing stratum by means of skin friction or end bearing or both. Pile foundations are regarded as a safe alternative for supporting structures in seismic areas and have been used for this purpose in non-liquefying as well as liquefying soils. But their design in case of potentially liquefiable soil is quite different from that of non liquefiable soil. In liquefiable soil the progressive buildup of excess pore water pressure will cause stiffness degradation and loss of strength which in turn will induce additional shear force and bending moment in the pile. The mechanism of pile behavior in liquefying soil has been investigated by several investigators in the recent years based on observations of pile performance during earthquakes and studies in the centrifuge and Shake Table tests. Exhaustive geotechnical investigation has been carried out along the proposed alignment of the Extradosed Cable Stayed Bridge i.e., along Baropara, Bansberia ROB, Ishwar Gupta Bridge, Saraswati River to collect disturbed as well as undisturbed soil sample, to develop average soil profile and to determine the design parameters. The proposed project site is very close to Eocene Hinge Zone, which is basically a strike slip fault, capable of generating an earthquake of Mw 6.7. Thus it is evident that the proposed Bridge needs to be designed considering the adverse geo-hydrological condition as well as the earthquake aspects needing special attention following the state-of-the-art technology as guided by relevant codes and published literatures. Considering the soil profile of these locations ground response analysis has been carried out using equivalent linear method to determine the site amplification. Site specific response spectra have been developed for the four zones and zone factors have been determined. The computed zone factors are 0.198g, 0.195g, 0.195g and 0.20g for the four zones respectively, much higher than the zone factor 0.16g, which is for zone III, as stipulated in IS 1893:2002."

Jan 1, 2015

By A. R. Dover

The Richmond San Rafael Bridge (Figure 1) is a 4.3 mile long major toll bridge span across northern San Francisco Bay. Tutor-Saliba/Koch/Tidewater (TSKT) conducted a comprehensive seismic retrofit, which was at the time Caltrans? largest-ever construction contract at $484 million. The robust foundation retrofit design of 11 bridge piers included the installation of 26 new, large diameter (126 to 162 inch OD, wall thickness 1.5 to 2.25 inches) CIDH and CISS piles, with steel pipe piles installed to tip elevations of Elev. ?140 to -220 ft, in water depths up to 70 feet. The open-ended steel pipe piles had initial sections ranging from 71 to 172 feet long, with full lengths that extended to the bay bottom and then through 100 to 130 feet of marine sediments to top of bedrock. The marine soils of most interest consisted mainly of soft to firm Young Bay Mud (YBM), a silty, moderately-sensitive clay common to SF Bay. A key constructability issue was the prediction of pipe piles ?running? under self weight (198 to 625 kips in air) and pile driving hammer weight (IHC S-500 with total assembly weight of 322 kips). The term "pile running" is used to describe the penetration of the pile into the soil due to the self-weight of the pile only. This issue was critical because 1) there was limited head room under the bridge deck, and 2) if piles run too deep, the pile splicing on several piles would be problematic (the lowest desirable pile top elevation after running was +10 ft). While running measurements are sometimes made during marine/nearshore construction, there is little published data on predicted vs. actual running. This paper discusses the running prediction under self weight for 26 piles, and the methodology used in developing the predictions, which ranged from 15 to 94 ft of penetration below mudline. Pile running was recorded and compared with predicted values. The prediction methodology was quite good, and no significant constructability problems were encountered. The authors ?tweaked? the model to provide a slightly improved prediction method. The paper presents the model, predictions, observations, and discusses important lessons learned.

Jan 1, 2006

By Lee S. Vanzler

Atlantic Wharf involved the construction of a six-level underground parking garage and a 32-story high rise tower along the historic Boston Harbor waterfront. The site, historically known as ?Russia Wharf,? consisted of filled land initially created in the late 1800s by extending the shoreline toward the harbor as the urban population and land needs grew to support expansion of commerce and trade. Redevelopment required solutions to address relics of waterfront structures (granite block seawalls, piles, and piers), weak subsurface soil conditions, tidal groundwater levels, and contaminated soils resulting from previous site usage and filling. The foundation system, consisting of drilled shafts with column loads up to 14,000 kips (62,272 kN), concrete diaphragm wall (slurry wall), and up-down construction methodology, was chosen to address these factors. As a prerequisite for development, selected portions of the façades of the former historic buildings were required to be preserved, protected, and incorporated into the final building configuration. The historic façades were temporarily braced and supported prior to the demolition of the buildings and commencement of below-grade construction. This paper will describe the considerations in the selection of up-down construction methodology along with a discussion of the design and performance of the concrete diaphragm wall and drilled shaft foundations. Up-down construction methodology shortened the overall construction schedule while addressing the lateral bracing requirements for the concrete diaphragm wall and restrictive ground movement tolerances to protect adjacent structures. Below-grade construction was completed in March 2010, and the building was opened for tenant occupancy in January 2011.

Jan 1, 2011