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By Peter Yen

This session consists of five papers. Three involved research on the properties of grout materials, specifically ultrafine cements and polyurethane grouts. Two papers present the development of soil grouting technology and monitoring methods. Of great interest are the papers on ultrafine grout penetrability testing focusing on the pressure filtration effects encountered in permeation grouting applications (Ericksson, Stille and Mittag, Savidis). The comparison testing of hydrophilic and hydrophobic polyurethane grouts submitted by Vrignaud, Ballivy, Perret and Fernagu assessed the long-term performance of these materials for repairing saturated cracks in concrete, subject to thermal expansion and contraction. Two very practical papers present the development of soil grouting, where permeation, fracture, replacement, jetting and other grouting techniques are utilized. The papers by Lees with Chuaqui and Warner present experience with ultrafine and other commonly used grout materials. Methods to measure and monitor the injection process and verify production progress are discussed.

Feb 10, 2003

By Terrence M. Carroll, Chu E. Ho

"A pile installation and load testing program on driven tapered piles was undertaken at John F. Kennedy International Airport in New York City for the extension of the existing Terminal 4. As part of the program, dynamic testing by means of the Pile Driving Analyzer (PDA) was performed on several preliminary test piles as well as production piles. The results of the dynamic tests and subsequent static load tests were reviewed to develop an understanding of the pile-soil response of a tapered pile during driving and after setup. Pile setup occurred as a result of increase in shaft resistance with virtually no increase in toe resistance. More than 150 tons of additional capacity was gained after the setup time.The capacities measured during driving from the PDA are typically used as the basis for determining the pile driving set criteria, with the required initial driving capacities determined largely by the contractor’s experience. An improved appreciation of the setup phenomenon is required to better refine the driving criteria at the end of initial driving such that the required ultimate capacities can be obtained, with reasonable confidence, after a period of setup.This paper presents interpretation of pile-soil behavior from Case Pile Wave Analysis Program (CAPWAP) analyses and discusses the mechanism of increased capacity as a result of setup effects. Time-dependent capacity gain as a result of setup effects should be based on the extrapolation of the shaft resistance component rather than the total pile capacity as is commonly practiced. Prediction of pile performance using this approach was in good agreement with observed static and dynamic load test results.IntroductionTapered piles have been adopted for various projects at John F. Kennedy International Airport (JFKIA) since the late 1940’s. Initially timber piles were used exclusively, with steel Monotube piles being used from at least the 1980’s (Horvath and Trochalides, 2004). The steel Tapertube pile was developed in the mid-1990’s and has commonly been used in recent construction (Brusey and Yin, 2008). The Tapertube piles used for this project consisted of a 25 foot long tapered section that was 8 inches in diameter at the tip and 18 inches in diameter at the top. An 18 inch diameter straight pipe was welded above the tapered section."

Jan 1, 2015

By William B. Conway

This paper will describe the large caisson pier foundations for four of the bridges crossing the Mississippi River in the New Orleans area; and will discuss some of the unusual problems encountered during their sinking. Certain settlement phenomena experienced during their service life will also be related: The four bridges in order of their construction: The Huey P. Long Bridge, River Mile 106.1, completed in 1935 The Greater New Orleans Bridge No.1, River Mile 96.0, completed in 1958 The Hale Boggs Bridge, River Mile 121.6, completed in 1983 The Greater New Orleans Bridge No.2, River Mile 96.1, completed in 1988 Each of these bridges employed large open-dredged concrete caissons as foundations for one or more of the river piers, with the smallest being the 65ft by 102ft caissons for Piers I and II of the Huey P. Long Bridge and the largest being the 99ft by 214ft caisson for Pier II of the Greater New Orleans Bridge No.2. The Huey P. Long caissons are founded in a dense fine sand at -170 while all of the other bridge caissons are founded in hard preconsolidated clay at elevations varying from -150 to -185. The Huey P. Long Bridge is currently being widened without increasing the caisson foundations under any of the river piers; and the design reasoning that led to this decision is presented.

May 11, 2007

By Vijaya Bhushan Rao, Jason Redgers

The typical Vibrocompaction projects undertaken in the UAE are on reclaimed Sands. These Sands which are predominantly the crushable, calcareous, carbonate sands found locally as opposed to the more common quartz or silica sands that are featured in most design literature. The famous reclamations such as the iconic Palm Jumeirah in Dubai, often have specification for mitigation of liquefaction induced settlements, bearing capacity increases and total and differential settlement requirements. Often these performance targets are achieved by the means of achieving a particular relative density that are generally measured by a defined Cone Penetration Test, CPT targeting values of cone resistance (Qc), MPa at respective depth zones. In this paper some case studies are presented, where soil suitability for deep compaction by vibratory methods was firstly assessed for suitability using the Massarsch, 1991 compactability chart prior to the application of vibrocompaction and its subsequent evaluation. One such project named the Island Development required 17 to 23m depth of penetration only to treat the lower 5 to 6m of sand above rockhead as eventually the top 15m of sand will be further excavated to allow for the construction of basement. The paper will present pre and post CPT results, the results of initial site calibration trials and evaluation of the completed works.

Oct 1, 2022

By Arash Saeidi-Rashk-Olia, Dunja Peric

Energy piles are gaining increased popularity due to a growing demand for clean energy. To further advance the understanding of soil-structure interaction in energy piles, recently-derived analytical solutions have been implemented to investigate the impact of stratigraphy on the soil-structure interaction. This was accomplished by comparing the measured and predicted head displacements, axial strains and stresses in an energy pile embedded in the actual homogeneous and layered soil profiles, as well as into synthetic homogeneous soil profiles. The analytical solutions for homogeneous soil profile captured the smooth experimentally observed response versus depth very well. In the case of a layered soil profile, the corresponding analytical model was capable of capturing nuances in trends of axial stress and strain versus depth at the interface of different layers. The analytical predictions for the layered profile appear to be slightly less accurate than for the homogenous profile. The experimental data obtained from the layered profile appear to be a bit more scattered than those from the homogeneous profile. In the former case, the interplay of the individual soil layers with the pile occurs while maintaining the continuity of the pile stress and displacement at the interface of different layers. The response throughout each layer of the layered profile is quantitatively different than the corresponding homogeneous response. Nevertheless, qualitatively the response throughout each layer of the layered profile is similar to the response of the pile embedded in the corresponding homogeneous layer.

Sep 8, 2021

By Dario Libano, Franz-Werner Gerressen

"Diaphragm walls are known as underground structural elements commonly used for retention systems and permanent foundation walls or elements. Of course they can also be used as deep groundwater barriers. This paper will focus on the construction work in an urban area like Sao Paulo. The Line 5 of Metro Sao Paulo is one of four network expansion projects undertaken at the same time. The projects will cover various areas of the city. The Line 5 on São Paulo’s south-side will be extended 7.1mi (11.5km) to serve 770,000 riders per day, stretching a total of 12.4mi (19.9km) along 17 stations. The extension line will facilitate access to the city’s central section and the commercial and hospital districts located along the line. The Brooklin Station, subject of this paper, had to be carried out in a special five shaft shape design, shaft diameter 131ft (40m) each, without using ground anchors. A focus will be taken on the special requirements of the installation of the arrows as well as on the specialties of installation for the shaft shaped layout. Therefore, it was required to install a 3.3ft (1,000mm) diaphragm wall using a specific layout especially in the connecting sections of the shafts, the so called arrows, to provide a bearing area for the struts. Maximum wall depth was about 121ft (37m); the total volume was about 20,060 cubic yard (15,337m³). The paper will describe the construction method and the sequence of activities required for the construction of this diaphragm wall using a combination of hydraulic grab and trench cutter system.INTRODUCTIONThe Line 5 Extension, in the city of Sao Paulo/Brazil, is currently the most important investment in public transport by Sao Paulo state’s government. It will connect the south part of the city to the city center, crossing through four other major METRO lines and stations, all currently in operation. The extension includes a new parking yard for the trains and 11 new stations. The Brooklin Station is one of the new stations and has a unique geometry of five secant shafts. The station should open and operate in 2016.The original design included constructing five secant shafts stabilized by two plastic slurry walls using conventional grab technology. One of them was to contain the contamination plumes in the neighborhood and the other for temporary support to enable the excavation of the shafts. The final retaining wall design was reviewed and changed to a concrete structural diaphragm wall. The reason of design change was as well the reduction of construction time of the shafts by half to meet the schedule as to avoid dewatering effects in a geological region characterized by Quaternary sediments and environmental contamination plumes. It was the first time that a trench cutter (hydromill) was used in such a situation in Brazil. The cutter increased the quality of the joints by overcutting, and decreased the probability of having seepage into the shafts. The cutter created a seepage barrier and avoided movement of contamination."

Jan 1, 2017

By Evangelia Ieronymaki

Civil engineering education relies on traditional methods of teaching, comprising mostly of deductive instruction by presenting the theory, followed by applications. This paper presents an alternative way for teaching foundation design to senior students, introducing a more inductive approach. The students are presented with a project/game adapted to a real-world problem at the beginning of the course. They are asked to identify the correct steps and methods throughout the lectures, for reaching an appropriate solution that they document and present at the end of the course. To make the project more enjoyable, the project has the format of a game where the students compete with each other on completing the task faster and more efficiently. The goal of this teaching approach is to enhance the ability of the students for problem solving and the engineering way of thinking, while playing a game. In the end, the students were requested to respond to a survey regarding the efficiency of this project/game on their learning. The results showed that students prefer more inductive methods for a design course, feeling that this project made them think more like engineers, while the ‘game’ twist of it made the whole course more fun. INTRODUCTION Most civil engineering courses are taught in 2019 the same way they used to be taught 40 years ago in the 80s. Classic methods are mostly deductive, where the instructor presents the theory first and then applications of that theory follow. Little or no attention is given initially to why the theory was developed or what are the problems it solves. The applications of the theory, and thus the purpose it serves, come only in the end and after methodologies have been presented, leading the students to show low interest in the material. As Albanese and Mitchell (1993) have reported, people are mostly motivated to learn things when they clearly see the need to know them. This explains the students’ little motivation that, if any, comes mainly from the fact that the material may be useful either in other courses or in their future careers. On the other hand, there are alternative inductive methods of teaching, where the role of the students is more active. A lot of researchers have highlighted the benefits of inductive methods in teaching engineering courses. Based on Prince and Fedler (2006), inductive methods include; a) inquiry-learning, b) discovery learning, c) problem and project-based learning (PBL), d) case-based teaching, and e) just-in-time learning. Inquiry-learning is maybe the most traditional method of inductive teaching/learning methods, where the instructor asks questions or poses problems and the students need to apply the theory they have learnt in order to find the solution (Bateman 1990; Prince 2004; Lee 2012). Similar to inquire-learning is the discovery learning, where students have to find the solution to a problem or answer to a question, while the instructor simply provides feedback to the students without guiding their efforts (Leonard 1988; Westbrook and Rogers 1994).

Jan 1, 2019

By Cheng Lin, Guoming Lin

"This paper presents a case history for the design, construction and long-term performance monitoring of a driven prestressed concrete (PSC) piled foundation supporting a large liquefied natural gas (LNG) tank in Savannah, Georgia, USA. Following a geotechnical investigation, a design stage pile test program was performed with three objectives: to study the densification effect from pile driving on the liquefaction resistance, to test axial and lateral pile capacities, and pile behavior under lateral loads. The test program comprised five piles driven on a test pad constructed adjacent to the tank foundation. Cone penetration testing (CPT) was performed before and after pile installation to test soil densification effects from the pile driving and liquefaction potential was re-evaluated based on the soil densities after pile installation. The axial load tests involved static load testing, high strain dynamic testing, and Statnamic testing. This paper presents the findings of the densification effects, compares results from different axial testing methods and discusses the procedures to use the load test results in the pile design. The paper also comments on the construction issues and presents performance data with 10 years of monitoring.1. IntroductionThe project site is located at the Kinder Morgan’s Elba Island LNG Terminal on the Savannah River which is three miles downstream of the downtown Savannah, Georgia. This LNG terminal was initially developed in the 1970s as an LNG import terminal. The facility includes five LNG storage tanks with two larger tanks which were constructed in 2003 and 2006, respectively. The terminal is currently being converted into a liquefaction and export facility. This paper discusses pile foundations for Tank D4 which is a double walled insulated steel tank built to hold one million barrels of LNG in 2003. This tank has an outer tank diameter of 258 feet, an inner diameter of 252 feet, and liquid height of 113 feet. A number of geotechnical challenges were present in the foundation design and construction.??The site is a typical coastal deposit site featuring a thick layer of very soft under-consolidated clay (up to 40 feet in thickness);??The bedrock is a couple of thousand feet deep;??There is a sand layer that is liquefiable under a high seismic design category (0.5% possibility of exceedance in 50 years)."

Jan 1, 1900

By Mohammed Faizal, Abdelmalek Bouazza

"The operation of ground source heat pumps combined with foundation piles can have an effect on the thermal behaviour of the pile and the surrounding soil. This paper presents the effects of continuous heating, continuous cooling, and alternate heating and cooling operations on ground and pile temperatures as well as the thermo-mechanical behaviour of a field scale energy pile. The effect of pile operation on the ground temperatures is highest near the pile and reduces with increasing radial distance. The results of the present studies generally showed that the thermal elasticity of the pile is not affected.INTRODUCTIONGeothermal energy piles are foundation piles used as underground heat exchangers to maintain thermal comfort in buildings, via the use of ground source heat pumps (GSHPs). Ground source heat pumps are more economical and environmental friendly compared to conventional heat pumps. Energy piles can be combined with supplemental surface heaters or coolers, known as hybrid systems, for forcefully recharging the ground during non-operational times of the GSHP. Alternative heating and cooling of the GSHP improves geothermal energy usage and alleviates heat build-up in the ground and provides a balance of ground temperatures around the heat exchanger (Jalaluddin and Miyara, 2012).The temperatures induced in the piles during GSHP operation can lead to a complex response of thermal strains and stresses in the pile concrete. An assessment of the thermo-mechanical response of energy piles for various thermal loads may assist engineers in the design process. Furthermore, an assessment of ground temperatures will also highlight any potential thermal interactions with other energy piles in actual building operations.At present, the thermal strain and stress distribution in field scale energy piles has mostly been studied for continuous operation (Laloui et al., 2006; Bourne-Webb et al., 2009; McCartney and Murphy, 2012; Akrouch et al., 2014; Mimouni, 2014; Murphy and McCartney, 2014; Murphy et al., 2014; Wang et al., 2015). These studies have contributed considerably to the understanding of the axial thermal strain and stress distributions in the piles and have shown that pile thermal behaviour is mostly thermo-elastic without inducing major structural concerns.The present paper adds to the current knowledge by assessing the pile thermo-mechanical and ground thermal response for continuous and alternating thermal loads of a field scale energy pile. The operation modes studied are 24 hours continuous cooling (Faizal et al., 2015), 24 hours continuous heating, (Wang et al., 2015) and alternate heating and cooling operation (Faizal and Bouazza, 2016). The forced ground thermal recharging is done during the non-operating times of the cooling unit, simulating a solar hybrid GSHP system for a scheduled intermittent mode of operation."

Jan 1, 1900

By Filippo Leoni, Wesley Schmutzler

"The LPV-111 East Back Levee Improvement Project lies along the Gulf Intracoastal Waterway (GIWW) in Orleans Parish of New Orleans, La., and is an essential component of the New Orleans Hurricane Protection System. The Hurricane Protection Office of the U.S. Army Corps of Engineers (USACE) attributed failure of the New Orleans East levees system to overtopping, erosion and subsequent breaching of LPV-111 along the GIWW, as well as other sections of flood protection during Hurricane Katrina in 2005. The existing levee suffered extensive damages from Hurricane Katrina, such that the USACE elected to provide earth stabilization and to rebuild the levee sections. Due to the adverse geotechnical properties of the foundation soils, the Corps deemed ground improvement necessary to stabilize the new levee and to limit its footprint. Wet Deep Mixing Method (DMM) was selected as the most suitable technology for this task.ChallengesDesign: This reach specifically protects East New Orleans and the Bayou Savage National Wildlife Refuge, the largest urban wildlife refuge in the U.S. and home to several threatened or endangered species of birds as well as many reptiles, amphibians and small mammals. The Corps chose DMM due to the sensitivity of the protected marshlands and because the method limits the footprint of the raised levees. The increase in the load bearing capacity of the treated soil significantly decreases the footprint necessary to attain the required height increase. This limitation required the new levee to have steep slopes, drastically increasing the surcharge on foundation soils characterized by overall poor geotechnical properties (soft clays and peats). The design also considered the increased horizontal stresses on the levees due to the extreme storm surges during a hurricane.The design of the 1.6 m diameter (5.25 ft) DMM elements called for overlapping them to form a double auger element that formed buttresses perpendicular to the levee alignment. The contractor installed the buttresses at a maximum on center spacing of 4.7 m (15.5 ft). One additional double auger DMM element was midway between consecutive buttresses at the centerline of the levee to further help prevent settlement (Figure 1)."

Jan 1, 2013

By Paul J. Sabatini, Robert C. Bachus, Terence P. Holman, Panos Andonyadis

A recent landslide comprising approximately 12 acres (4.86 hectare) and a displaced volume of more than 500,000 cy (382,000 m3) caused the shutdown of a four-lane state highway and two high-capacity freight railway lines. After completion of immediate landslide stabilization activities, various long-term slope stabilization measures were implemented that focused primarily on gradual slope unloading in areas near and upslope from the scarp of the landslide. Near the completion of the upslope excavation, an anchored soldier beam and lagging wall was constructed to allow for the temporary unloading of the toe of the main landslide area to facilitate installation of a permanent underdrain. The design of the anchored wall utilized information collected during the rehabilitation construction and included inclinometer data, site survey results, piezometer data, and field construction observations. Using the history of site-specific movements, results of back-analysis calculations from the landslide, and geometry/performance of the post-construction slope configurations, the fully softened and residual shear strengths along two potentially critical sliding surfaces were calculated. Owing to the high confidence in the values of shear strength as afforded by this information, the confidence in local groundwater conditions, and control of the loads, the designers selected a relatively low, calculated short-term factor of safety (FS) (i.e., FS ˜ 1.1 to 1.2) for the most critical unloading step. Long term calculated FS values on the order of 1.2 to 1.3 were anticipated. This paper describes the detailed evaluation of the landslide slope movement data associated with the shallow and deep potentially critical failure surfaces and selection of the associated values of design shear strength for these potentially critical surfaces. A description is presented of the analyses and design of the anchored wall, measures implemented during construction to minimize slope movements, and post-construction monitoring results during the unloading and subsequent installation of the underdrain.

Jan 1, 2017

By James G. Ulinski, Sebastian Lobo-Guerrero, Vishal B. Patel

"Recently modified design equations used in the transportation industry to calculate side friction and end bearing capacity for drilled shafts are now providing more realistic estimations of capacities than did previous methods. Using multiple case studies and test results from various projects, a more realistic design approach was formulated by the Federal Highway Administration (FHWA), which resulted in greater values of ultimate capacity for side friction and end bearing and in a more efficient design overall.In 2010, the FHWA published GEC-10 – Drilled Shafts: Construction Procedures and LRFD Design Methods, which illustrates a different method of calculating side friction and end bearing resistance and results in greater values for design. In 2014, the Association of State Highway and Transportation Officials (AASHTO) adopted the method put forth by FHWA, which was included in its LRFD Bridge Design th Specifications, 7 Edition. The Pennsylvania Department of Transportation (PennDOT) recently adopted and incorporated the similar methodology as AASHTO for calculating side friction and end bearing for drilled shafts in rock, and these changes are reflected in the 2015 edition of the PennDOT Design Manual, Part 4 (DM-4). This article discusses the past and current design methodology along with a project case study with results from Osterberg Cell (O-cell) load testing, which presents a comparison between the design resistances of ultimate side friction and end bearing and the measured capacities at failure.The Old and the NewEditions of the AASHTO LRFD Bridge Design Manual from 2012 and earlier estimated ultimate side resistance, qs, in rock using the following equation (modified from Horvath and Kenney, 1979):qs=0.65aEpa(qu/pa)0.5 < 7.8pa(f ’c/pa)0.5 where: qu is the uniaxial compressive strength of the rock in ksf; pa is the atmospheric pressure in ksf; aE is the reduction factor to account for jointing in rock; and f ’c is the compressive strength of the concrete in ksi. For intact rock, previous versions of the AASHTO manual required that the ultimate end bearing resistance, qp, was calculated using the following equation: qp=2.5qu."

Jan 1, 2017

By Jun Ohbayashi, Yoshiyuki Yagiura, Hiroaki Miyatake, Masuo Kondoh, Naotoshi Shinkawa

"Reducing the improvement ratio of ground improvement is an extremely efficient way to reduce the construction cost and construction period of mitigation measures for soft ground. The Arch Action Low Improvement Ratio Cement Column (ALiCC Method) is one method for this, and it is being increasingly applied to sites. This method enables us to rationally evaluate the embankment loads that are acting on cement improved soil columns and unimproved ground, by considering the arch action generated in the embankments and from there thusly allocate improved soil columns in spans of a greater distance than those needed for conventional methods. As a result, it serves to reduce construction costs and the construction period, while also minimizing the settling of the embankment and differential settlement, by placing numerous improved soil columns in the ground immediately beneath the embankment at equidistant intervals. In this report, we give a basic overview of the ALiCC Method, report typical construction results from real life cases that have been carried out, and make comparisons with other construction methods in order to report on the effectiveness of this design method.OVERVIEW OF ARCH ACTION LOW IMPROVEMENT RATIO CEMENT COLUMN (ALiCC) METHODIn the area of mitigation measures for soft ground, a significant role is played by ground improvements using improved materials such as cement. For this reason, a reduction in construction costs and construction period required for ground improvements has become of greater importance. The Public Works Research Institute carried out joint research with Kiso-Jiban Consultants Co. Ltd., Kitac Co. Ltd., and Fudo Tetra Co. Ltd. over a period from 1998 through 2002, and, from that, developed the ""Arch Action Low Improvement Ratio Cement Column Method"" (hereinafter referred to as the ""ALiCC Method"") that enables ground improvement with a lower improvement ratio (the improved area ratio is approx. 10% to 30%) than is required for conventional methods, while also ensuring stabilization and minimizing the settling of embankments.In the area of mitigation methods for soft ground by deep mixing, the dominant method until now has been that (50% or more of improvement ratio) shown in Fig. 1. This method comprehensively improves the area under the face of the slopes of both sides of the embankment. This is based on the calculated stability against rotational slip, which states, ""the most effective way to ensure the stabilization of the embankment environment is to carry out improvements of the area under the face of the slope."" Therefore, for the area under the face of the slope, ground improvement by deep mixing was done, and for the soft ground in the area under the middle part of the embankment, accelerated consolidation methods (hereinafter referred to as ""conventional method"") such as sand draining method and paper draining method were used. Mitigation measures that combine these improvement methods have also been mainstream for a long period of time and are used to prevent side deformation around the embankment. However, there have been some problems that have occurred, such as a situation where consolidation settling occurs in the center area under the embankment where no improvement had been carried out. This phenomenon leads to a situation in which the improved soil columns in the area under the face the of slope are pushed to the outside, which results in side deformation occurring around the area of the embankment, and additionally the occurrence of a step due to a situation of differential settlement between the improved ground and the consolidation advancing part, which results in cracks in the embankment."

Jan 1, 2015

By Sara Moshfeghi, Seyyed Majdeddin Mir Mohammad Hosseini, Abolfazl Eslami

"Due to variety of current pile bearing capacity methods based on the cone penetration test (CPT), for optimum design, it is necessary to evaluate the performance of such methods in different geotechnical conditions. Geotechnical databases including piling and in-situ testing records have been recognized as useful tools for analysis, design and economical construction. In order to evaluate pile bearing capacity methods, AUT-CPT&Pile database has been compiled including 450 full scale pile load tests and CPT sounding records. This database consists of different pile types with a relatively wide range of geometries and various soil conditions. Forty three records of piles driven in sand deposits were then employed to evaluate effects of ultimate capacity interpretation criteria from load displacement diagrams. The Davisson offset limit criterion, the Brinch Hansen 80% criterion and the load at the displacement of 10% of the pile diameter were compared to estimated capacities from ten CPT based design methods currently used in practice. The Brinch Hansen 80% criterion and the load at the displacement of 10% of the pile diameter lead to reasonable results, the Brinch Hansen 80% criterion showed less scatter. For evaluating the accuracy and the precision of CPT-based methods, the results were compared to estimated capacities. Results of comparison indicate that the CPT-based methods mainly predict the pile capacity withreasonable accuracy.INTRODUCTIONAmong the different approaches of estimating the pile bearing capacity, in-situ tests, especially, the cone penetration test (CPT) are favored due to the cone similarities with piles in modes of installation as well as fast and continuous profiling. This trend is practically well established where deep foundations are to be constructed in soft to medium subsoil deposits (Eslami and Fellenius, 1997; Mayne and Niazi, 2009).Employing different design methods results in a wide range of values which complicates the selection of an appropriate one to determine the pile bearing capacity. Several studies by Briuad and Tucker (1988), Eslami and Fellenius (1997), Abu Farsakh and Titi (2004), Schneider et al. (2008) and Eslami et al. (2011) confirm disparity of different design methods predictions. Thus, for optimum design, it is necessary to evaluate and compare the performance of current methods.Geotechnical databases are known as helpful tools in research and practical applications for optimizing analysis and design and are mainly used for management and interpretation of data, evaluation of design methods, calibrating LRFD or ASD design factors, etc. Pile lateral and axial load tests are examples of databases in geotechnical engineering. A summary of several CPT and pile load test databases is presented in Table 1."

Jan 1, 2017

By Charles M. Wilk

"Solidification/stabilization (S/S) treatment is used to treat hazardous wastes for disposal and in the remediation/site restoration of contaminated land . SIS is also an increasingly popular technology for Brownfield (industrial property) redevelopment, since treated wastes can often be left on-site and to improve the soil for subsequent construction. This paper discusses the applicability of the technology to various wastes, basic cement chemistry relating to SIS, tests used to design treatability studies and to verify treatment, basics on implementation of the technology in the field , and examples of SIS use at brownfield sites, including a former wood preserving site, former manufactured gas plant sites, a former electric generating station, and a shopping mall development.INTRODUCTIONSolidification/Stabilization (S/S) is a widely used treatment for the management/disposal of a broad range of contaminated media and wastes; particularly those contaminated with substances classified as hazardous in the United States. The treatment involves mixing a binding reagent into the contaminated media or waste. The treatment protects human health and the environment by immobilizing contaminants within the treated material. Immobilization within the treated material prevents migration of the contaminants to human, animal and plant receptors. SIS treatment has been used to treat radioactive wastes since the 1950s and hazardous waste since the 1970's (Conner 1990). SIS continues as a cornerstone treatment technology for the management of radioactive waste, hazardous waste, and site remediation and Brownfield redevelopment."

Jan 1, 2005

By Theodore von Rosenvinge

Large diameter (2.4 meter) drilled shaft foundations were installed to depths of over 62 meters through soil into Arkose bedrock for Connecticut?s Pearl Harbor Memorial Bridge (I-95 over New Haven Harbor). The project involved many ?firsts? including the first ?extradosed? cable-stayed bridge in the US, and for Connecticut, the deepest drilled shafts, the first use of a rotator to install shaft casing, and the first use of the Mini-Sid technology for rock socket bottom inspection. Design utilized both friction and end bearing for rock sockets. O-Cell testing was employed to maximize performance factors during design and to allow adjustments to socket lengths during construction. Favorable test results permitted a reduction in socket lengths and significant cost saving.

Jan 1, 2011

By Emre Biringen

"Results from a small-scale laboratory experimental program show the changes in the vertical stiffness and strength of a soft clayey soil adjacent to the shaft of an inserted pile (i.e. expansion of a cylindrical cavity). The experimental program provides a realistic axi-symmetric physical model of an element of a cylindrical pile and the surrounding soil. The study interprets the improvement and assesses its magnitude in vertical stress-strain-strength properties of a normally consolidated soft cohesive soil in response to preloading impact in the radial direction. The results verify that insertion of a cylindrical pile causes densification of surrounding soil in a radial direction due to change in stress state around the pile, and thus consolidating and stiffening of the soil.The test results indicate that most improvement in modulus and strength takes place within a distance of 4 times the radius of a pile, though significant improvement is realized to a distance of 8-10 times the radius, beyond where there is negligible effect. Settlement characteristics of the surrounding soil in a zone of 12 times the pile radius improve significantly after the formation of a cylindrical cavity. The miniature vane shear strength tests show a 1.5 times increase in a zone of 4 times the pile radius compared to the strength at 10 pile radii. The results also imply that the spacing of cylindrical piles should not be more than 4 to 10 times pile radius, so that the surrounding soil matrix may improve the vertical bearing capacity under any foundation or embankment loading.INTRODUCTIONThe engineering community is familiar with different techniques to improve the bearing capacity and settlement characteristics of weak cohesive and organic soils. Some of the in situ techniques to improve the properties of soft ground (e.g. soft clays) prior to placement of foundations are vertical preloading, deep cemenUlime mixing, stone columns, and grouting (Henn 1996; Moseley 1993). In addition to these methods, researchers have recently showed interest in achieving soft ground improvement by means of applying radial compression method for which different names exist including expanding pile (Kelleher et al. 2001 ), Preload™ Pier (Biringen and Edil 2003), and sand compaction pile (Lee et al. 2004). Handy (2001) has described how preloading can also be achieved by imposition of radial loading in soft ground with an expected improvement in stiffness. The idea behind the latter method is densification and consolidation of soft soil in the radial direction by controlled displacement for which the process can be viewed as a cavity expansion problem (Vesic 1972)."

Jan 1, 2005

By Kevin Kuhl

With the destruction of the US-90 Bridge spanning St. Louis Bay by Hurricane Katrina, the State of Mississippi awarded its first major design-build contract in order to have a completed four-lane bridge in a period of less than two years. The structure consists of 76 pre-cast concrete beam spans with a total bridge length from Bent 1 to Bent 77 of 11,124 ft (2.1 miles). All 77 bents are founded on pre-cast, pre-stressed concrete piles and consist of two foundation types: pile bents and water line footings. A total of 53 pile bents were utilized where the deck is less than 52 ft above the water. Further divided, 10 pile bents, supported by 24 in. square, solid piles, are located on land. The remainder of the pile bents are located within St. Louis Bay and supported by 36 in. square, voided piles. All the waterline footings are supported by 30 in. square, voided piles. In total, 138 -24 in., 437 -30 in., and 463 -36 in. piles support the structure. Production pile design was based upon information gathered from the subsurface investigation, design soil profile and 23 out-of-position test piles. Verification of the design was established by monitoring the first production pile driven at each bent using the Pile Driving Analyzer. Particular challenges included highly variable coastal deposits, loads in excess of 1600 kips per pile and a compressed construction schedule. Initial drive capacity of a portion of the production test piles was less than expected resulting in a minimum 14 day setup. Following the setup period, restrikes were necessary to verify capacity. Project production piles ranging from 50 ft in length to in excess of 160 ft in length were used to achieve the required resistance. This paper includes a brief overview of the foundation design and indicator test pile program. The main objective is to provide a summary of the quality control procedures including establishing the driving criteria for each bent and to present issues that arose during production pile driving and the solutions that followed.

May 11, 2007

By Julie Clarke

In 1939 Dr. Ralph Peck criticized the Civil Engineering community for taking a bifurcated approach to the prediction of building damage due to subsurface geo-technical works. Specifically, he observed that Geotechnical Engineers concerned themselves only with subsurface issues implying that their results were largely independent of the presence and condition of the structures above. He continued that Structural Engineers charged with risk assessment of buildings approached their work nearly in isolation of below ground activities. Seventy years later, although the state-of-the-art has enabled a better understanding of soil-structure interaction, the reality remains that risk assessment from subsurface construction, is not yet an integrated activity when done on a large-scale basis. To help move beyond this, this paper proposes a new, integrated methodology for preliminary assessment that considers a three-stage process that involves the following: (1) traditional empirical relationships for predicting ground movement from tunneling, (2) recent advances in condition assessments, and (3) architectural designators related to usage and historic preservation listings. The methodology is applied to a study area of nearly 260 buildings in the city center of Dublin Ireland, in an area slated for an upcoming metro. The results are com-pared to the Environmental Impact Statement issued for the official project. Al-though the test case is for tunneling, the approach may be adapted to other subsurface construction activities including excavation and piling.

Jan 1, 2009

By Qingwei Joshua Ong

Tension piles, also known as uplift or anchor piles, are necessary to resist uplift forces that might cause structural distress. In excavation projects, most uplift forces are developed because of hydrostatic pressures, and so tension piles are subjected to a great deal of tensile forces. Most current methods of design for tension piles completely neglect the tensile strength contribution of concrete, relying only on the steel members to carry the tensile stresses, resulting in an overly conservative design. The stressstrain behavior of the composite material of concrete and steel must be considered for a realistic simulation of tension piles. This paper will examine a case on a tension bored pile in typical soft clay to demonstrate the importance of considering the tension strength and tension softening of the concrete.

Nov 1, 2022