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By Chris D. Shewmaker

So you want to install 2,600 augered cast-in-place piles, about 155,000 lineal feet, in 33 working days? It can be done. The Public Service Enterprise Group (PSEG) decided to build a combined cycle power plant in Lawrenceburg, Indiana. PSEG selected Fluor Constructors Indiana, L.P. to design and build the plant. Fluor Constructors, in turn, selected Richard Goettle, Inc. to install the piles. The initial plan was to install the 2,600 piles in 33 days, working six (6) ten hour days per week. After successfully installing and performing four pile load tests - up to 300 ton capacity - we set out to complete the work and meet the aggressive schedule. After three weeks of installing an average of 75 piles a day with three drill rigs, Fluor relaxed the schedule because we were so far ahead of their projected construction sequence. We elected to continue drilling on a ten-hour day, five days a week schedule. In all, we installed nearly 2,800 piles, totaling 175,000 lineal feet, in about 47 days.

Jan 1, 2004

By Bruno Gemmi

A new warehouse built with prefabricated components over an area underlined by soft marine soil deposits started showing differential settlements well before its completion. Its 103 spread footings carrying up to 4,000kN (450t) axial loads had been cast on jet-grouted columns extending and penetrating a layer of sand at a depth of 10m (33ft). Investigations performed to assess the wholeness and consistency of the jet-grouted columns revealed a state of loose jet-grouted masses and uncontrolled, off target migrations of the jet-grouting. Most of the jet-grouting itself was settling. The following remedial solutions were suggested: 1. Construction of new and better controlled jet-grouted columns. 2. Cement-based soil grouting. 3. Expanding resin injections. 4. Minipiles drilled-through the existing footings and reaching into a denser layer of sand existing at 23m below grade. Remedial solution 1. was immediately discarded due to cost and the possibility of a repeating failure in this non-granular and highly compressible soil. Tests of remedial solutions 2. and 3. were carried out. The outcome of the grouting was monitored by Electro Resistivity Tomography (ERT) (Bares et al., 2003), an innovative 3D electro tomography procedure showing where grout had been actually placed and its migrations off target. A successful 4,000kN (450t) load tests confirmed the validity of the solution. Finally, upon the completion of a successful load test, solution 4. was chosen. It supplied the highest degree of reliability thanks to the ease of controlling the final and actual location of the minipiles and to the higher safety factor provided. All remedial work to install the minipiles was eventually performed inside the building. Additional load tests and settlement measurements confirmed the adequacy and success of the chosen solution.

Jan 1, 2011

By Brian D. Barkauskas, Terence P. Holman

A major combined nuclear and coal-fired power plant, located in on the western coast of Florida has undergone multiple upgrades in recent years to increase power output and enhance environmental controls. Construction of new elements within the existing plant structure required working in highly congested conditions and heavy crane lifts with large picking radii. The largest crane pick involved the use of an 1800 metric tonne capacity Mammoet PTC ring crane for a single long-radius, high altitude lift of a precipitator unit. Original bid tender documents had called for drilled shaft foundation support, but the presence of many critical utilities and unfavorable access for cost effective construction led specialty contractor Moretrench American Corporation to propose an alternate micropile foundation on the basis that high capacities could be achieved in the weak limestone geology and that the smaller size of micropiles would allow for more surgical installation in the utility-congested areas. This case history describes the design and construction of seventy three (73) high capacity micropiles for the value engineering alternative and the crane foundation for this critical lift. Each micropile was founded in a competent dolomitic fossiliferous limestone unit at typical depths of 23 m below existing ground surface. Strain gauge instrumented load testing was used to validate the geotechnical design parameters in the weak limestone bedrock and resulted in the finding that the entire test load was being carried in the upper half of the bond zone. Construction of the production micropiles required numerous relocations due to utility conflicts and local reanalysis and redesign of the 1.2 m thick reinforced concrete ring beam cap. Crane foundation performance was satisfactory and the effective life of this temporary foundation was only 6 months before decommissioning and demolition.

Jan 1, 2017

By Maria Flessas, Justin Ray, Danielle Steinmetz, Brian Zuckerman

"The Ventura County Medical Center Hospital Replacement Wing project consists of the construction of a 2- to 3-story building with a basement encompassing the entire footprint and two corridors connecting the new hospital wing to existing buildings. The site is located in the Ventura Basin where strong ground shaking has been observed during moderate to large earthquakes on nearby faults. The upper 90 feet of the soil consists of loose to medium dense finegrained sands and low plasticity silts that are potentially susceptible to liquefaction, seismic densification, and hydroconsolidation. Ground settlement associated with a large seismic event on a nearby fault is estimated at 20 to 26 inches. To account for the anticipated ground settlement, auger pressure grouted (APG) piles gaining support below the potentially liquefiable soil were selected for the support of the proposed structure. Challenges for pile design included the anticipated earthquake-induced ground settlement, high downdrag loads, low soil lateral capacity during strong ground shaking, and the effect of pile installation on the performance of the existing adjacent buildings and the installed shoring system. The replacement hospital is supported on over 600 APG piles, with lengths varying between 120 and 140 feet. Axial pile capacities were verified with an extensive indicator pile installation program and dynamic pile load testing.INTRODUCTIONThe Hospital Replacement Wing (HRW) project is at the Ventura County Medical Center (VCMC) in Ventura County, Southern California (Figure 1). The VCMC consists of three interconnected hospital buildings (Buildings 303, 304, and Fainer Building), the Medical Laboratory/Cafeteria Building, two mental health buildings, a medical office building, an emergency generator building, and surface parking lots. The HRW is near the center of the campus, adjacent to several existing buildings.The HRW is a 2- to 3-story structure, with a 15- to 20-foot-deep basement beneath the entire 95,000-square-foot building footprint. The HRW project includes a Loading Dock, a four-level corridor to the Fainer Building (Fainer connector), and a two-level corridor to the Medical Laboratory/Cafeteria Building (Café connector). The corridors are structurally separated from the existing buildings. Typical dead plus live load column loads for the HRW range from about 635 kips to 935 kips and total loads range from about 860 kips to 1,295 kips."

Jan 1, 2016

By Brandon M. Robinson, Osman F. Besler, Dominik Gaechter

The Sandbukta-Moss-Såstad (SMS) project is a part of the Intercity development project, which is part of the largest transport project in Norway, consisting of 270 km of new double-track rail. The SMS project consists of 10km of double-track railway including three open stretches and two tunnels. Soil conditions consist of quick clay underlain by Bedrock. Dry soil mixing (DSM) was considered as the main soil improvement method to allow for excavation of the quick clay and construction of the D-Wall panels. The preliminary design revealed around 25,000 ton of binder installation. Therefore, a test field has been conducted to evaluate binder alternatives in means of improved soil strength by considering CO2 emissions. Multicem and Standard cement (Standard FA) have been compared for that purpose. Multicem is a type of binder which mainly consists of Portland cement and cement kiln dust (CKD). CKD is a fined-grained, solid, highly alkaline material removed from the cement kiln exhaust gases. reverse column penetration test (FOPS) and pre-drilled column penetration test (FKPS), which are common tests to evaluate DSM strength have revealed comparable strength outcome for both binder types. Therefore, Multicem has been selected as the main binder type to be used further which provided a reduction in CO2 footprint of up to 40%.

May 1, 2022

By M. A. El-Sohby

The paper describes some problems encountered with the foundation of a deep drainage caisson constructed on the Nile Bank in Cairo. The use of suction dredging while sinking the caisson led to a piping failure of the sandy soil in the base which was loosened during the process of pumping. A study was carried out to investigate the problem and a procedure was adopted to retain the stability of the caisson.

Jan 1, 2010

By Zhu Tonghao

A method of calculating anti-slide pile, sheet pile, underground diaphragm and structure with anchors etc. is proposeed in the paper. The effect of the various layers of soil, anchors and bracings etc. on laterally loaded structures may be considered in the model. In the analysis the structure is divided into a series of elements. The transfer matrices of both deformation and internal force are established for each element. According to continuous condition neighbouring element should be connected. Thus the deformation and internal force of each element can be found out in conbination with boundary conditions. The method has a wider adaptability and it can be applicable to a great variety of the analysis of interaction between various structure and soil. If parameters in model are selected properly, the computed results would be in good agreement with the measured data.

Jan 1, 1991

By Mark M. Petersen

As part of the addition of eight new combined cycle generating units at the Florida Power & Light Sanford Plant, 2,129 piles were to be installed. The existing plant elements were supported on driven piles, and the variation in pile lengths during previous work, as well as available subsurface information, indicated a complex stratigraphy. At the request of the owner, the designer/construction manager developed a program to evaluate the use of pressure-grouted displacement piles. A pre-design load test program in areas that represented the apparent extremes in subsurface conditions indicated that the system was feasible; however, the presence of existing features that were to be demolished later precluded the clear delineation of subsurface conditions in advance of construction. A contract was negotiated with the pile installer based on the best estimate of potential pile lengths, with modifications to pile lengths to be set based on additional exploration. A total of 52 cone penetration soundings and five load tests were performed immediately prior to and during pile installation to establish correlations between the CPT data and pile performance. Pile depths were set based on these correlations. Pile installation was completed 6 weeks ahead of schedule and 15 percent under the original budget estimate. This paper documents the evaluation of pressure-grouted displacement piles as an emerging technology, and illustrates the benefits of a close working relationship between the owner, designer, and pile contractor at a site with variable subsurface conditions.

Jan 1, 2002

By Paul Doherty

Expansion of the global piling industry has been coupled with significant research efforts investigating the mechanisms controlling pile capacity. Static pile design has transitioned from total stress approaches toward effective stress design, with associated improvements in predicting pile performance. As a result, the available literature is heavily skewed toward static capacity prediction. However, when considering piles offshore, the majority of loading is not static but highly variable and cyclic in nature. This paper outlines the additional factors that require consideration for cyclic pile design, including elevated loading rates, cyclic displacements and capacity degradation. A review of the literature identified a number of cyclic pile testing programs which are collated in this paper. General trends are established through comparison of the tests within the database and the conditions where cyclic loading is most likely to be a concern are identified. In particular, loading conditions which involve full plastic shear reversals are seen to cause the most extreme cyclic damage, with the degraded capacity as low as 31% of the precyclic static capacity. The underlying mechanisms which can result in cyclic damage are explored, with particular attention given to the pore pressure response, radial stresses, shear transfer and particle reorientation.

Jan 1, 2009

By Alain Pecker

The choice of a design concept for a bridge foundation is guided by various factors; several of these factors are indeed of technical origin, like the environmental conditions in a broad sense, but others non technical factors may also have a profound impact on the final design concept. The foundations solutions adopted for the Rion Antirion bridge are described and an attempt is made to pinpoint the major factors that have guided the final choices. The Rion Antirion bridge is exemplar in that respect: the foundation concept combines the simplicity of capacity design, the conceptual facility of construction and enhances the foundation safety. The design of these foundations was a very challenging task which required full cooperation and close interaction with all the parties involved: concessionaire, contractor, designers and design checker.

Jan 1, 2005

By Jesús E. Gómez

In the Summer of 2011, emergency repairs to the Jefferson Memorial North Plaza and Seawall were completed. These repairs were necessitated by settlement and lateral movement of the seawall and North Plaza which prompted the National Park Service (NPS) to initiate an investigation as to the possible causes of the movement, and commission a design for its mitigation. Information gathered from extensive instrumentation on site led to the design of a movement mitigation scheme that included demolition of the Ashlar Seawall and reconstruction of a new seawall. The new seawall foundation is an A-Wall consisting of vertical caissons and battered pipe piles connected to the seawall itself. The scheme provides resistance to future vertical and lateral movement of the North Plaza and the new seawall. Repair to the seawall and plaza began in December 2009, and was completed in August 2011. This paper discusses the mechanisms believed to be responsible for settlement and lateral movement, summarizes the procedure followed for design of the mitigation, and describes the construction methods and some challenges faced during the repair.

Jan 1, 2011

By K. Mallikarjuna Rao

There are several methods available to estimate deflection and ultimate Capacity of laterally loaded piles. In this investigation an attempt has been made to verify the existing methods for prediction of ultimate lateral resistance and deflection with the laboratory and field test results reported in the literature. A 75 pile loading test data obtained from the literature was used to evaluate two methods designed to predict the ultimate lateral resistance of rigid piles and three methods designed to predict the lateral deflections of rigid piles and four methods designed to predict the lateral deflection of flexible piles subjected to lateral loads. The accuracy and precision of each method is quantified statistically. The statistical results of the overall analysis indicate that the mean values of the ratios of predicted to measured lateral capacities vary from 0.62 to 1.14 with an average of 0.88. However, the settlement predictions were much more widely scattered than the ultimate load predictions and in general all the methods have a tendency to under predict the deflections. A new method is proposed by modifying the Broms's method to estimate the lateral deflections of free headed rigid and flexible piles separately. The proposed modified methods were found to be reasonably good in comparison to existing methods and to overestimate deflections.

Jan 1, 1996

By Hayel M. El-Naggar, Sherif A. Akl

Although grouted piles have been used for several decades since the idea was proposed in the 1970s, their design is mostly based on experience and unpublished proprietary methods. There is little research on grouting drilled shaft tips and even less on grouting shaft sides. This paper presents the analysis of 4 instrumented pile loads tests on base and shaft grouted piles from different sites in Egypt; with emphasis on one of the tests, to demonstrate the analysis process. The data from the tests are analyzed to model the development of unit side friction (USF) with relative displacement. A numerical model using the finite element software PLAXIS is used to investigate the effect of grouting on the surrounding soil stress state. The paper combines the observations from full scale pile load tests and results from the numerical model to suggest an idealized behavior of side friction development with relative displacement of the grouted part of the shaft. The suggested model considers an envelope of Unit Side Friction (USF) with relative displacement, initially dominated by the grout resistance then at higher relative displacements, the friction with radially pressured soil takes over. The grout provides very high USF values up to a relative displacement of 2mm. Then, the USF drops to a typical pile soil side friction behavior; however, this friction is affected by the contact stress between pile and soil, which significantly increases due to compaction grouting. INTRODUCTION Base and shaft pile grouting has been significantly developing in recent years to accommodate the unfavorable conditions in major projects such as the high loads in high rise building and founding on problematic soil formations. Grouting aims to decrease settlements and increase the capacity of the pile under axial load. The technique is first introduced by Kraft (1974) but gained popularity in the 1980s. Typically there are two types of grouting; compaction, and permeation. Compaction grouting is more common in pile foundations practice, and many researchers have provided case histories of pile load tests on base grouted piles and base and shaft grouted piles (Gouvenot and Gabaix,1975; Stocker, 1983; Ghazali et al., 1988; Fleming, 1993; Kusakabe et al., 1994; Robson and Wahby,1994; Joer and Randolph, 1998; Hamza and Leoni, 1998; Mullins et al. 2000; Littlechild et al., 2000; Suckling and Eager, 2001; Dapp and Mullins, 2002; Ho, 2003; Fu and Zhou, 2003; Brettmann and NeSmith, 2005; Ruiz, 2005; Mullins, 2006; Dapp and Brown, 2010; Beadman et al., 2012; Nguyen et al., 2013; Miller et al., 2013; Sinnreich and Simpson, 2015; Hui and Lin, 2015). Compaction grouting is meant to densify the soil around the pile and below the base rather than permeate this soil and increase its cohesion. Research showed that grouting increases the capacity of the piles by a factor of 2~5. The variation in capacity increase depends on pile type, grouting process, and especially grouting pressure. Although there are many case histories of pile load tests on grouted piles but there is no well-defined agreed-upon method to predict grouted pile capacity as typically done in ungrouted piles. Few lab experiments discussed the shaft grouting effects on the soil especially the compaction grouting. The experiments concluded that the compaction grouting forms a homogeneous layer between the pile and the soil, and a residual effective stress is achieved simultaneously with a significant densification of the soil around the pile with noticeable decreasing in void ratio. (Fattahpour et al., 2015; Wang et al., 2015). Recently, studies used numerical analysis to investigate the behavior of the grouted piles and the changes in the surrounding soil (Chiang et al., 2013). That study presents a simulation of the base pressure grouting with a simple FE model and predicts the reduction of the pile settlement by 10 to 20%. Another numerical study using a complex model conducted by Zhou et al. (2017), pr

Jan 1, 2018

By Sven Schröer, Lilma Schimmel, Dimiter Alexiew

"The Geotextile Encased Columns (GEC) deep foundation system for embankments on soft soils was introduced some 20 years ago and is now considered State-of-the-art worldwide.The GECs consist of compacted granular fill, similar to common gravel columns, with one decisive difference: they are confined in a high-strength low-strain flexible geotextile “cylinder” (encasement). This engineered element provides a very efficient tool to control and optimize the behavior of the system. GECs perform very well even in extremely soft soils ensuring bearing capacity (stability) and reducing settlements. Due to the encasement, they a lso provide high lateral ductility. A wide range of fills including sands can be used.The remarkable reduction of vertical stresses in the soft soil surrounding the GECs results in a decrease of lateral pressure as well. Such reduction combined with the lateral ductility allow GECs to be also used for lateral pressure-relief adjacent to sensitive foundations, e.g. rigid piles. The application of GECs as lateral pressure relief was recently used in Brazil and Germany where bridge abutments were built on concrete reinforced-piles. The GECs below the bridge approaches and adjacent to the piles decreased the lateral pressure to acceptable values.This paper presents two case studies for which the most relevant parameters, the geotechnical conditions, specific problems, engineering philosophy, final solution and lessons learned are discussed. Furthermore, instrumentation programs were applied in both projects. The most important results in terms of displacements and stresses are shown, evaluated, summarized and commented upon, focusing on the lateral stress-relief, followed by conclusions and recommendations."

Jan 1, 2016

By Chu E. Ho, Paul Napoli

A new waterfront park was developed on Long Island in close proximity to the East River and Newtown Creek. The existing ground consisted of fill over soft organic clay, medium dense silty sand, glacial till and schist bedrock. The ground was initially raised to preload the underlying soft soils to stabilize the ground in preparation for site development. The ground was subsequently cut down to temporary grades for installation of foundation piles for the overlook structures and construction of reinforced concrete cantilever retaining walls forming pathways located adjacent to the water bodies. The retaining walls were located in two rows at different elevations along the sides of a steep embankment. Where the pathways converge, some of the walls were too close to each other, and were redesigned as a combined U-wall with a common base slab. The individual retaining walls were designed for adequate bearing, sliding and overturning resistance. Ground anchors were installed to enhance global stability of the retaining walls. This paper presents the design considerations for the retaining walls for various loading conditions, and evaluation of the trial and proof tests for the anchors. INTRODUCTION The New York City Master Plan included the transformation of an approximately 30-acre parcel of land in Long Island City, Queens, New York from a former manufacturing zone into a residential, commercial and recreational zone for middle-income community. The site was located at Hunters Point South along the eastern shoreline of the East River and Newtown Creek (Figure 1). The development included low to high- rise residential buildings, a public school, and retail structures. Open spaces were provided along the East River and Newtown Creek waterfronts in the form of a continuous park providing for recreational and community-related activities. Waterfront structures included small park buildings, walkways and viewing platforms. The shoreline was surrounded by revetments as part of the flood mitigation strategy. The project involved extensive site re-grading and several retaining walls were constructed. The earthwork volume amounted to approximately 47,000 cubic yard of imported fill and 93,000 cubic yard of cut. The exposed height of the retaining walls ranged from 3 to 15 feet. This paper focuses on the design and construction of the retaining walls for the project.

Jan 1, 2019

By Franklin M. Grynkewicz

The subject of bearing pile performance installed by vibratory hammers has been a matter of increasing study and continued controversy. A recent case study from a major bridge replacement project is discussed which provides encouraging data on the use of vibratory pile hammers as a primary means of pile installation and also presents the problems associated with its general acceptance. The bridge project case study foundations consisted of HP 14 x 89 pile sections, designed to develop capacity primarily in friction. Preliminary tip elevations were determined by traditional static analyses. Production pile installation was performed using an IHC S-70 Hydro-Hammer. Driving criteria and final production pile tip elevations were determined after preliminary indicator pile drive tests and static load test results at bridge pier cofferdam locations. Based on impact driven production pile performance, the Contractor wished to investigate vibratory driven piles as a means to accelerate construction schedule. Dynamic pile testing procedures were used as the primary measurement tool and test results were compared to the production pile drive records and prior static load tests. Field testing consisted of driving and monitoring with the PDA impact driven piles to the design tip elevation. Three vibratory driven piles were installed to the same tip elevation and immediately subjected to impact driving and dynamic testing to compare dynamic pile resistance. The results indicated that the site soil conditions were favorable for vibratory pile hammer installation. Recommendations and procedures for proceeding with vibratory hammer pile installation were presented to the Owner. These procedures included quality control in conformance with latest AASHTO recommendations. The Owner, in spite of the site specific data base and QA/QC procedures, would not accept vibratory pile hammer installation, due to the absence of precedence. It is concluded that for vibratory methods to become accepted a rational method of analysis, design and field QA/QC procedures requires development. In addition, the engineering community and Owners/Agencies must be more open to alternate methods of foundation construction. The continued development of dynamic methods of monitoring vibratory pile installation is considered to be key to the general acceptance of this installation procedure.

Jan 1, 1991

By Joan Stoupa

The expansion of the West Point wastewater treatment plant located in Seattle, Washington, will require a permanent tieback retaining wall to enlarge the plant site for the new treatment plant facili­ties. The retaining wall will extend approximately 3,000 feet along the property boundary between the treatment plant and the neighboring Discovery Park. Wall heights will range from 35 to as high as 65 feet. The purpose of the retaining wall is to provide a more uniform grade on the plant site and to resist lateral pressures exerted by the upslope, unstable hillside. During preliminary design of the retaining wall, various wall systems were evaluated based on assumed subsurface soil conditions. Results of preliminary studies indicated that expected subsurface conditions and wall heights made a permanent tieback retaining wall feasible. However, uncertain loads on the wall and the capacity of anchors in the native soils were significant. As a result, a detailed geotechnical program was conducted. The scope of the program included conventional drilling, sampling, analyses, and a field test program to determine site-specific anchor capacities. This paper describes the anchor test program and results.

Jan 1, 1990

By Gao Dazhao

This paper presents some research results of pile foundation performance. Measurements on the bearing behaviour and driving effects of piles have been carried out during pile testing and pile driving. It has been found that the ratio of end resistance to the ultimate load depends on the pile length, and the ratio in general is less than 40% for single piles. However for pile group, the end resistance seems to be greater than skin friction. The characteristic curves of skin friction and end re­sistance appear as interaction between soils and pile. The contribution of skin friction to the pile bearing capacity not only depends on soil properties but also on the relative position of the soil layer. The pore pressure and the lateral pressure in ground have been observed during the stage of driving piles. Based on the available data, the radius of plastic region and the coefficient of pore pressure A can be found analytically. The pore pressure time process curves which may be used for practice have been predicted by means of numerical method.

Jan 1, 1991

By Stefan Larsson, Sebastian Adevik, Sadek Baker, Razvan Ignat

"Abstract Uncertain strength, deformation and flow properties in dry deep mixing columns often lead to conservative choices concerning design values where the design is regularly complemented with a surcharge fill. The surcharge not only leads to increased cost but also to logistical problems where the surcharge is a physical obstacle. The deformation properties of a ground improvement were studied by means of two small embankment load tests. The settlement measurements were also used in FEM analyses, where the effect of surcharge on creep settlements was investigated. Based on the results, the effects of the surcharge were considered negligible and could safely be ignored. The project is an example how the contractor can use a field test as an effective design approach.IntroductionGround improvement of soft soils with dry deep mixing columns, or lime-cement columns, is often combined with a surcharge fill. The main reason for using a surcharge is to force the primary settlement and some of the secondary settlement that would have occurred under the final embankment height alone, to take place under the surcharge loading. Another reason is to level out uneven settlements. Strength and deformation properties in improved soil cannot be sufficiently assessed in advance, before columns have been tested on-site, and this uncertainty often lead to conservative choices concerning design values. In order to compensate for a slow forecasted consolidation process, the design is regularly complemented with a surcharge. The surcharge not only leads to increased cost but also to logistical problems where the surcharge is a physical obstacle.Extensive research undertaken by Åhnberg (2006, 2007) shows, by means of triaxial and oedometer tests, that cementation processes and a load acting on the columns during hardening, makes the improved soil to behave as a heavily over-consolidated soil due to an increase in quasi pre-consolidation pressure. The effects of using a surcharge on the time for consolidation and creep properties are thus probably small, since the stress level does not normally exceed this quasi pre-consolidation pressure. A study presented by Venda Oliveira et al. (2013) shows that the stress level within small ranges has limited effect on the creep properties.This paper presents a case study where the deformation properties of a ground improvement using dry deep mixing columns was investigated by load tests on two small test embankments. The tests were performed at the Interchange Värtan project site, which is part of the Norra länken infrastructure project in Stockholm. The tests were not performed as a research project but simple load tests performed by the contractor with the purpose of rationalizing the design delivered by the client. One purpose of the load tests was to assess the deformations when the columns are loaded temporarily by overlaying concrete works. Another purpose was to provide some input data to a study of the effects of using surcharge on creep settlements. The analysis was conducted as finite element modeling using the commercial code PLAXIS, where creep settlements can be simulated using the built-in Soft Soil Creep model."

Jan 1, 2014

By Takefumi Takuma, Hiroyuki Nishimura, Shigeru Kambe

"Japan’s Great Tohoku Earthquake and the immediately following tsunami of March 11, 2011 killed more than fifteen thousand people and destroyed numerous buildings and infrastructures in the northeastern part of the country.In addition to reconstruction projects in the areas where the earthquake and tsunami hit, other seismically vulnerable regions in the country have started building new and more robust facilities as well as upgrading existing coastal structures so they will be able to cope with such deadly seismic and hydraulic force. This paper will highlight two different types of aseismic and anti-tsunami levee upgrades currently under construction on the coast of Kochi Prefecture, approximately 500 miles west of Tokyo. The first type is the installation of double sheet pile walls in existing seawalls. The second type is to drive tubular piles into existing levee structures for reinforcing them. Both sheet and tubular piles are being driven by the Press-in Piling Method without removing or compromising the function of the existing structures. 1. BACKGROUNDGreat Tohoku Earthquake of March 11, 2011 caused severe damage to many structures. ASCE’s survey of damaged coastal structures conducted immediately after the disaster by Ewing, et al. (2014) categorizes failure modes of the structures in the following manner.?Overtopping without structural failure.?Overtopping with structural damage or failure.?Wave uplift forces.?Movement of structure off foundation from sliding, rotation, or overtopping.?Impact loads.?Hydrostatic pressure.?Supercritical flows.?Scour.?Erosion.?Abutments end effects.?Subsidence."

Jan 1, 2017