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By K Ilamparuthi, R. K. Madhumathi

"This paper presents the results of 1g model tests conducted on model piles both single and two pile groups embedded in sand by physically inducing lateral soil movement. From the test results it was found that the pile with higher L/D ratio exhibits higher deflection in case of pile embedded in medium dense sand whereas in loose sand the response is vice versa with higher deflection for the pile of lesser L/D ratio. The induced bending moment in piles is more for longer piles than shorter piles irrespective of the density of sand bed. It is also found that the pile head deflection and the bending moment are found to decrease exponentially with increasing distance between the pile and the wall. For pile group arranged in a row parallel and perpendicular to retaining wall, the deflection of single pile is more than the deflection of two pile group irrespective of the depth of excavation for spacing of piles tested. The influence of soil movement on the lateral response of pile is also analyzed through 3-dimensional finite element analysis. The numerical results thus obtained are validated with the results of experiments. The Mohr-Coulomb material model adopted to represent the soil behaviour predicts the response of pile reasonably and compares well with the experimentally observed response.INTRODUCTIONPile foundations are adopted to support structures such as foundations of high rise buildings, transmission towers, offshore platforms, bridge abutments etc., when good bearing stratum is not present at shallow depth to bear the loads of these structures. In the recent past particularly in the urbanized areas structures are built close to one another and nearby excavation will cause a reduction of lateral earth pressure and soil movement behind the retaining wall (Ong, 2004). The reduction in support stress will induce additional movement to the pile and leading to distress in pile foundations located adjacent to supported excavation. In these situations understanding the response of piles next to supported excavations becomes essential.The behavior of piles subjected to soil movement was studied by Poulos and Chen (1996 and1997) through tests on 1g models and the findings concluded that the maximum bending moment was found to decrease with decreasing pile diameter and decreasing pile spacing . Leung et al. (2000 and 2003) studied the effects of excavation induced soil movement on pile foundations in sand through centrifuge tests and established that the restraints on the pile head would cause additional shear force and/or bending moment at the pile head, although the restraints help to reduce the pile head deflection/rotation. In the theoretical studies of Poulos & Chen (1997), boundary element method (PALLAS) was used for analysing the pile subjected to lateral soil movement and charts were proposed for designing the piles. Pan et al. (2002) and Miao et al. (2006) analysed the passive pile behavior through three dimensional finite element analyses. However research works reported on piles subjected to lateral soil movement are limited."

Jan 1, 2015

By Steven E. Darnell, William W. Haasz, Brandon T. Buschmeier, Frederic Masse

"Landfills often cover expansive areas in locations where large building facilities or infrastructure is in high in demand after the land has been reclaimed. Most landfills have soil or fill properties that vary widely over small distances; combined with the strict guidelines and restrictions for the removal and treatment of soil or material that is on site, these projects can be a major challenge for any prospective developer. In order to make landfills suitable for the construction of any project it is necessary to conduct a detailed evaluation of the subsurface conditions. Ground improvement techniques are among the most typical methods for making reclaimed landfills suitable for the construction of any major project. The paper will discuss the approach that was taken to support a proposed warehouse in Elizabeth, New Jersey using Controlled Modulus Columns Rigid Inclusions (CMC Rigid Inclusions), which are grouted, auger-displacement elements. Additionally, we will discuss the use of Dynamic Compaction (DC) that was performed in areas outside the proposed warehouse footprint. Through the combination of CMC rigid inclusions and DC, the general contractor’s project schedule was expedited, the costs to support the warehouse were economized, and the anticipated settlement of the parking lot areas was drastically reduced. Furthermore, the paper will outline the benefits of using CMC rigid inclusions and DC methods in order to minimize the impact of working with contaminated soils from a landfill.OVERVIEW OF THE ELIZABETH WAREHOUSE PROJECTOver the past several decades the foundations industry has seen an increase in demand for the support of developments on reclaimed landfills; particularly, on the east coast where many landfills were capped before the 1980’s and steady population growth and city expansion have caused high demand for this now highly desired real estate. Unfortunately, these landfills, often as large as twenty (20) or more acres present tough geotechnical and environmental challenges for Owners planning to develop or build structures of any size on the reclaimed land. Consequently, the options for building on reclaimed landfills can quickly become cost prohibitive.Site SpecificSelected by a developer for the location of a future warehouse, the 29 acres (114,424 sq-meters) project site is located in Elizabeth, New Jersey and demonstrates the complexities of designing over a once reclaimed landfill. The landfill was used for municipal solid waste (MSW) consisting of trash, wood, metal, glass, plastic, brick, concrete fragments, and other types of debris. This landfill was capped in the 1960’s, and developed in the 1970’s for a warehouse. The new project included the demolition of the existing warehouse and the development of the site to be repurposed for a new 481,650 sq-ft single-story warehouse, surrounded by paved parking and truck loading areas. Figure 1 below, shows an overview of the project site layout."

Jan 1, 2017

By Chetan D. Savani, Mike K. Muchard

The necessity to evaluate undocumented foundation lengths is essential in assessing the useable life, need for scour protection, retrofitting, or full reuse of existing bridge foundations. For this purpose, Parallel Seismic Testing (PST) has the best accuracy and is applicable to the widest range of foundation configurations used in bridge construction of any test method. Although not limited to bridges, PST case studies are presented involving two bridges. To preface the case study discussions, an overview of the PST method is given along with its results and analysis thereof. In one of the cases, we were afforded the rare opportunity to see the existing piles being extracted long after the PST testing program was completed. The resulting Class A prediction reaffirms the accuracy of the method. Versatility of the PST method is also exemplified in the two cases presented, where unique situations from complex foundation systems were overcome by analysis to provide successful results.

By Pathik Deb Mallik, Shyamal K. Mitra, Rajiv Kishore, Shuvranshu Rout, Manos De

"This paper presents a case study on the design and construction of a deep underground pit structure constructed inside almost a century old existing plant building. The complexity and challenge for the design and construction lay in executing the work in a difficult subsoil condition especially the presence of deep mica schist. The limited space availability in the existing plant for construction work without hampering regular production in other adjoining areas of the plant made the execution more challenging. Experience with difficult subsoil and proximity to old foundations entailed a non-conventional engineering approach while ensuring complete safety in spite of maintaining the normal operation.INTRODUCTIONTata Steel Processing and Distribution Limited (TSPDL) is a subsidiary unit of Tata Steel Limited (TSL) having a CR processing facility inside the premises of Tata Steel Limited. TSPDL intended to install equipment for a new slitting line inside the existing shed including construction of very deep structure called “loop pit” where the strips from cut CR sheets collect in the form of loops and are recovered as scrap. The entire plant is located within the shed of existing plant. The construction of all foundations including the loop pit is to be executed in the limited area without disturbance to normal production work in balance areas of the plant and also maintain safety and integrity of existing structures.The existing shed is an old structure constructed approximately 80 years ago. The building column foundations are gravity type design of brick masonry supporting only the vertical load from the columns. This type of foundation designed with no eccentricity of loading provides no allowance for implementing any foundation stabilizing design. The present project required civil construction for the new equipment foundations safely within this area."

Jan 1, 2015

By Raffaella Granata, Daniele Vanni

"This paper presents the drilling and grouting program performed at two abandoned landfills located into former calcarenite rock quarries in Manfredonia, Italy. Tests performed after the abandonment of the landfills detected leachate infiltration into the groundwater, which required the implementation of a remedial program. In order to seal the rock fissures and create an impervious basin at the base of the two landfills, sub-horizontal boreholes were drilled and grouted into the rock under the waste deposits. At the same time, sub-vertical boreholes were drilled and grouted along the perimeter, to laterally confine the landfills. Finally, the landfills were properly capped with an HDPE membrane, geogrid, geotextile and topsoil. The methodology implemented to create a watertight barrier under the two landfills was innovative and cost-effective. Moreover, the drilling and grouting minimized the environmental impact of the remedial work, since the waste remained in their original location and were not affected by the remedial process.IntroductionThe two landfills, “Pariti-1 RSU” and “Conte di Troia”, are located approximately 6 km (4 miles) southwest of Manfredonia, a small town close to Foggia, Italy (Fig. 1). These landfills are located into two rock quarries, formerly used for the extraction of calcarenite (i.e., a weak calcareous sandstone, in tuff facies), and were abandoned in the early 90s. The two landfills cover a total area of about 45,000 m2 (11.2 acres), and mainly include urban solid waste with a depth of up to 25 m (82 ft). The main characteristics of the two waste landfills are listed in Table 1."

Jan 1, 2016

By Amanda R. Parry, Chris R. Pray

Predicting and modeling the soil structure interaction of laterally loaded piles with significant unbraced lengths is one of the challenges faced in designing many waterfront structures. Designers often rely on pile specific design software to calculate forces in an embedded pile and then couple that with either a structural design software to capture the behavior of the rest of the structure or use potentially overly conservative assumptions to omit modelling the piles entirely. Given that some projects have hundreds of piles coupled with hundreds of loading conditions, the shuttling of results from the structural analysis software into the pile analysis software can become cumbersome, difficult to track and manage, and prone to user input errors. An alternative approach recently used on two large marine infrastructure projects consisted of calibrating a structural analysis software to replicate the resultant outputs from a software developed specifically for pile analysis. This calibration was done using thoughtfully placed springs along a pile modeled in the structural analysis software to replicate the soil-structure interaction of the piles. The focus of this paper will be on the methodology used to calibrate the two software programs and an evaluation of the results which showed close agreement. Based on the two case studies, calibrating a generic finite element analysis software via this method should be considered as a reasonable and time saving design approach for pile-supported structures.

Sep 8, 2021

By George Filz, Morales, Carlos, Bertero, Filippo Maria, Alessandro, Leoni

"The Deep Mixing Method (DMM) represents a viable solution to improve adverse geotechnical properties of foundation soils for many practical applications. A pre-construction soil investigation campaign is necessary to assess soil properties and to retrieve samples of different soil layers for a laboratory Bench Scale Testing program (BST). The BST has to be designed using various binder types, binder contents, and water/cement ratios in each of the soil types. Following the laboratory program, a full scale Field Test (FT) is typically necessary to verify the results of the BST. This paper will highlight the differences and the importance of performing both pre-construction laboratory tests and field tests to ascertain the proper mixing parameters in the different soil layers. Comparative analyses and interpretations between the lab and field stages, along with accumulated information about soil properties and quality control (QC) results, allow fine-tuning the production parameters throughout a project. Three Deep Mixing Method projects, where both laboratory and field tests were executed, are illustrated: (1) The LPV 111 Project (New Orleans, LA, USA): DMM was used for ground improvement/foundation strengthening to stabilize and support the burden of a new levee raise; (2) The Rio Puerto Nuevo Project (San Juan, PR, USA): DMM was applied to improve the soils adjacent to a 90"" forced sewer main relocation and to improve the soils for the base of a new drainage channel; and (3) State Road 83 (US 331) over Choctawhatchee Bay project (Walton County, FL, USA): DMM was applied to stabilize the causeway sections of the bridge enhancement project. Data recorded during laboratory and field tests for these projects were analyzed and interpreted to select the most appropriate construction parameters to provide a final high-quality product.INTRODUCTIONThe Deep Mixing Method (DMM) represents a viable solution to improve adverse geotechnical properties of foundation soils in many situations. The effectiveness of working parameters depends largely on the physical and mechanical properties of the soil to be treated. Therefore, well designed laboratory and field test programs, aimed to disclose the interaction between the site-specific soils and the mixing parameters, are essential to achieve the desired end product.Generally a pre-construction soil investigation campaign has to be performed to assess soil properties and to retrieve samples of different soil layers for the laboratory Bench Scale Testing programme (BST). The BST has to be designed using various binder types, binder contents (or cement factors - CF), and grout water/cement ratios (W/C) in each of the soil types; the selection of the different combinations and dosages for the BST is based on past extensive experiences on similar materials. Following the laboratory programme results, a full scale Field Test (FT) has to be designed and executed, installing several DMM elements to verify the results of the BST and fine tune the construction parameters, with the appropriate binder type and dosage and the most effective equipment and tool configuration."

Jan 1, 2015

By Mahdi Soudkhah, Akhter Hossain

Vertical micropiles are generally considered to be low in lateral resistance. Therefore, battered micropiles are often used when additional lateral load carrying capacity is required. However, battering of micropiles can sometimes be restricted due to existing adjacent structures or utilities, especially in highly urbanized areas. For example, presented in this paper are lateral load test data from a 43-story building project in New York City where vertical micropiles were used due to proximity to adjacent structures. Three static lateral load tests were conducted on micropiles consisting of 13.375-in-outside diameter and 25- to 51-ft-long casings, and socketed 10 to 12.6 ft into the bedrock (gneissic schist). The subsurface profile above the bedrock consists of loose to very dense, mostly sandy and silty soils. The design load for the three test piles was 14,000 lb and the maximum load applied during the tests was 200% of the design load. Lateral load- displacement behavior of the free pile heads from the load tests are compared with the results of p-y analyses based on a widely used p-y method for sandy soils and using a lower and an upper bound estimates of soil index properties and strength parameters. Since the existing p-y curves were formulated for larger diameter driven piles at a specific geographic location, major differences are observed between the results of the load tests and the p-y analyses. In general, the lateral displacements estimated based on the p-y analyses using upper bound soil parameters are relatively closer to the results of the field load testing. Modified p-y curves specific to the sandy and silty soils representative of the general subsurface conditions of New York City matched with the lateral load tests are presented in this paper. INTRODUCTION Micropiles generally are limited in lateral load carrying capacities due to their relatively higher slenderness ratios (ratio of depth to diameter) compared to more conventional deep foundation alternatives, such as driven piles and drilled shafts. So, micropiles are not typically considered as deep foundation solutions when significantly high lateral loads are expected on the substructures. Various means to increase the lateral resistance of micropiles include battering and installing an oversized casing in the top portion of the piles (FHWA 2005; and Richard and Rothbauer 2004). However, it is often not possible to install micropiles in a battered position in highly urbanized areas due to existing adjacent structures or utilities. Installation of oversized casing is often restricted by limited space availability and concerns of losing lateral capacities due to closely spaced group of piles. Thus, estimation of lateral resistance of vertical micropiles can become highly important for geotechnical engineering projects in urban areas when a small to moderate amount of lateral resistances are expected from the substructures, often to withstand seismic and wind loads.

Jan 1, 2019

By Karen Dawson, Patricia Bennett

Designers and constructors of King County’s $275M Georgetown Wet Weather Treatment Station located in Seattle, WA, overcame classical Puget Sound Lowland geotechnical challenges to provide treatment of 70 MGD of combined sewer overflows (CSOs), provide 1.2 MG of CSO storage, and convey the treated effluent 1,600 ft to a new outfall in the Lower Duwamish Waterway. The site is underlain by over 200 ft of very soft to dense deltaic deposits with moderately high compressibility, low strength, and is susceptible to seismically-induced liquefaction. The industrial history of the area made contamination a consideration for deep foundation selection and restrictions on construction methods. This paper describes some of the key aspects of the project, including a water-holding structure able to tolerate more-thancommonly-accepted settlement by utilizing a robust reinforced concrete slab and relatively short rigid inclusions combined with load distribution mat, settlement monitoring and water preloading prior to constructing grade-sensitive features. Case history information is presented for construction of a nominal 100 ft diameter, 92 ft deep secant pile intake pumping station/equalization basin which utilized a 32 ft thick tremie seal to reduce construction dewatering risks.

Oct 31, 2023

By Ali Azizian, Brian Hall

"Driven piles were selected to support the Fraser Heights Bridge bents. Piles were a key component of the top-down construction approach, which was adopted for minimizing potential impacts on an environmentally sensitive wetland. Project requirements mandated verification of pile capacities using dynamic methods. More than 40 Pile Driving Analyzer (PDA) tests were performed. The subsurface conditions were highly variable. On the east side, piles extended through loose sands, soft silts/clays, and two peat layers and were founded in glacial till-like soils at about 45 m depth. However, on the west side, till-like materials were so shallow that it was difficult to drive the piles sufficiently deep to obtain the necessary lateral support. This paper provides an overview of the geotechnical considerations of the bridge design and top-down construction approach, and expands on the presentation of PDA results and how they compared to pile capacity estimation methods and parameters recommended in the applicable design codes.INTRODUCTIONThe Fraser Heights Bridge (FHB) was a component of the Fraser Heights Connector (FHC), a 2 km section of the South Fraser Perimeter Road (SFPR), constructed as part of the Port Mann/Highway 1 (PMH1) Improvement Project. The FHC is located in northeast Surrey BC (Fig. 1).Two major design and construction determinants were: 1) a mandated tight schedule to provide a non-tolled alternative to a new toll bridge; and, 2) an obligation that construction had to occur with minimal impact on the environmentally sensitive wetland the FHB crossed, including limiting the footprint of the permanent and temporary works to less than 45 m2, and prohibiting construction access onto the wetland. Construction equipment was only allowed on the wetland on temporary trestles or on the finished structure. This latter requirement resulted in the bridge being constructed span by span, using a top-down approach."

Jan 1, 2016

By Donald T. Robertson, Kurt Hecht, Michael K. Muchard

"This paper presents case histories of driven concrete pile damage detected with dynamic testing methods utilizing strain gages and accelerometers embedded in the pile at the prestressing yard during pile construction. Data from the embedded instrumentation is compared with data taken with external bolt on instrumentation and other test methods such as low strain testing on the same pile. In the most severe cases, the piles were extracted revealing and corroborating the embedded data collector results.INTRODUCTIONDynamic testing of driven pile foundations was originally developed in the late 1960’s and commercialized in the early 1970’s. While the methods of analyzing dynamic test data have improved with the advancement of computer technology, the test method and the sensors used to acquire the data have changed little. In 1998, under a research grant provided by the Florida Department of Transportation, (McVay et al, 2002) an Embedded Data Collector system (EDC) was developed. The collector utilizes two sensor packs, each consisting of one strain gage and one accelerometer, embedded near the pile toe and pile top. Utilizing the toe sensor pack, the system provides reliable real time pile end bearing capacity measurements. This end bearing capacity is combined with a Case Method Solution augmented with an automatic damping calculation to provide the overall pile capacity, pile skin friction capacity and pile end bearing capacity. Also, since the gages are embedded, they have the ability to track all changes from the casting yard (i.e. prestress), driving, and subsequent setup (freeze, relaxation, etc) at both the top and bottom of the pile."

Jan 1, 2017

By Caciola Jr. Joseph J., Nidal M. AbiSaab

"Thanks in great part to the geology of the New York City Metropolitan area, mini-caissons are a popular choice for deep foundations. These drilled elements are readily available, easy to install with minimal impact on adjacent structures, and can be designed with large compressive and tensile capacities. Despite the frequency with which they are employed, the engineering design community is divided over several of the underlying principles governing the design of mini-caissons. This paper seeks to draw attention to several of these issues in an effort to encourage further research and discussion, namely: (1) how the allowable stresses have changed for the NYC Building Code over time, (2) the inconsistent load transfer mechanisms considered for geotechnical capacity, and (3) the role of the permanent steel casing towards structural capacities of mini-caissons.INTRODUCTIONIn the local construction nomenclature, mini-caissons are drilled deep foundation elements which derive their capacity from a socket in rock. A permanent steel casing (commonly between 7- and 24-inches in diameter) aides the drilling through overburden soils to the top of bedrock. Afterwards, an uncased rock socket is drilled into the bedrock and the inside of the casing and rock socket is inspected by means of portable video equipment. After inspection, the interior of the socket and casing is filled with steel reinforcement and concrete or grout. The casing-soil interface is generally ignored for axial design purposes and the full geotechnical compressive or tensile capacity is assumed to be generated in the rock socket. Figure 1 shows a typical mini-caisson cross section.Mini-caissons have been used for decades in the New York City area for a number of reasons. They have historically been proven to develop high axial capacities in the city’s metamorphic rock (Tamaro et. al. 2000), often exceeding 300- to 500-tons. Additionally, their method of installation (drilling) is generally able to bypass layers of dense Glacial Till, boulders, and manmade fill which would interfere with the installation of other pile types (e.g. driven piles, auger cast piles). Further they are able to extend to depths exceeding 50-ft to reach bedrock underlying a site, making them a useful tool in areas where rock is relatively deep or varied in elevation. Drilled casing installation also results in fewer vibrations and disturbances to adjacent structures and can occur in areas of restricted access (a constant concern for any project in a dense urban environment such as NYC)."

Jan 1, 2016

By Leonardo Massone

The p-y method is one of the most popular methods in pile design and has been calibrated for various boundary conditions using numerical and experimental studies during recent years. Most studies on reinforced concrete (RC) piles have included the impact of flexural nonlinearity, (e.g. nonlinear moment?curvature relations) but not considered associated pile shear deformations when deriving p-y curves from field data. Common p-y curves may be better applicable for piles with flexure dominated failures (e.g. piles with free- head boundary conditions). For piles with fixed head boundaries (i.e. rotation restrained piles) shear deformations could be of significant influence. To study this problem, a coupled shear flexure interaction model for axial-bending-shear behavior coded in OpenSees is applied to a 0.61 m flagpole and a 0.61m fixed head pile specimen to investigate the possible influence of shear deformations to the overall pile responses. The surrounding soil is represented by p-y curves derived from prior large scale testing on piles with similar boundary conditions. Analysis results show that for flagpole piles, shear forces and shear deformations were insignificant. Considerable contributions of pile shear displacements and forces were observed for the fixed head pile, with shear displacements contributing up to 40% of the total pile displacement. Results suggest that nonlinear shear deformations for reinforced concrete piles should be considered for fixed-head or similar conditions, and that currently used p-y curves may underestimate the actual lateral pile displacement and possibly lead to unsafe design for the particular boundary condition.

Jan 1, 2011

This Section describes four alternative methods for load testing of drilled shafts: high strain dynamic test (HSDT), rapid load test, static load test, and bottom load test. Until recently, static load tests were the only method available for verifying the capacity of a drilled shaft. However, because many drilled shafts carry very high design loads, the static load test was prohibitively expensive. The alternative methods, HSDT, rapid load testing, and bottom load testing are gaining acceptance because of their lower cost and faster implementation. However, these different methods do not necessarily yield the same results. This section describes the load testing methods and the differences that may occur when interpreting the test results.

Jan 1, 2004

By Mohamed Mekkawy, William W. Wheaton, Ira Brotman

"The Virginia Port Authority and the U.S. Army Corps of Engineers are partnering to construct the Craney Island Eastward Expansion (CIEE) to meet the dual purpose of extending the life of Craney Island as a dredged material management area and providing land for a state-of-the-art marine terminal. The over 500-acre (200-hectare) expansion provides additional upland dredged material capacity for the Hampton Roads Harbor by constructing perimeter dikes, that once filled, will provide land for the development of a container terminal. In the winter of 2010/2011 the first stage of sand fill was placed, followed by the installation of approximately 12 million linear feet (MLF) (3.6 million linear meters, MLM) of marine PVDs. With over 36 MLF (10.9 MLM) of PVD required to complete dike construction the project will be one of the largest PVD installation project in the U.S.This paper details the challenges associated with the construction of the cross dikes, in particular the design, testing, installation and monitoring of prefabricated vertical drains (PVDs) installed overwater to depths of over 130 feet (40 meters) for foundation improvement in the insitu very soft Norfolk Clay. With expected settlements of 20–30 ft (7-10 m) and 30 percent average strains, the discharge capacity of the PVDs was of particular concern. Laboratory data is presented showing the magnitudes and variability of discharge capacity under different confining pressures in both a straight and buckled condition.The method of installation and monitoring of the marine PVDs in open water included developing a specialized barge and sophisticated positioning and data collection system to verify installation location, depth of penetration and track quantities. An observational method, including material testing, detailed surveys, periodic in-situ testing, and instrumentation, was utilized by the project team to assess the project’s progress and allow for validation of consolidation and strength gain rates and magnitudes."

Jan 1, 2017

By Ira Brotman

The Virginia Port Authority and the U.S. Army Corps of Engineers are partnering to construct the Craney Island Eastward Expansion (CIEE) to meet the dual purpose of extending the life of Craney Island as a dredged material management area and providing land for a state-of-the-art marine terminal. The over 500-acre (200-hectare) expansion provides additional upland dredged material capacity for the Hampton Roads Harbor by constructing perimeter dikes, that once filled, will provide land for the development of a container terminal. In the winter of 2010/2011 the first stage of sand fill was placed, followed by the installation of approximately 12 million linear feet (MLF) (3.6 million linear meters, MLM) of marine PVDs. With over 36 MLF (10.9 MLM) of PVD required to complete dike construction the project will be one of the largest PVD installation project in the U.S. his paper details the challenges associated with the construction of the cross dikes, in particular the design, testing, installation and monitoring of prefabricated vertical drains (PVDs) installed overwater to depths of over 130 feet (40 meters) for foundation improvement in the insitu very soft Norfolk Clay. With expected settlements of 20?30 ft (7-10 m) and 30 percent average strains, the discharge capacity of the PVDs was of particular concern. Laboratory data is presented showing the magnitudes and variability of discharge capacity under different confining pressures in both a straight and buckled condition. The method of installation and monitoring of the marine PVDs in open water included developing a specialized barge and sophisticated positioning and data collection system to verify installation location, depth of penetration and track quantities. An observational method, including material testing, detailed surveys, periodic in-situ testing, and instrumentation, was utilized by the project team to assess the project?s progress and allow for validation of consolidation and strength gain rates and magnitudes.

By Ali Ebrahimi, Jeremy M. Gasser, Cuneyt Gokmen, Paul J. Sabatini, Roneet Das, William Tanner, Amir Ahmadipur

There are safety concerns related to operation of heavy equipment over coal combustion residual (CCR) impoundments during construction of the impoundment closure programs. As part of a pilot study prior to a full-scale closure construction, an access pathway and working platform were designed and constructed to facilitate equipment access for construction of deep soil mixing (DSM) zones on the ash delta of a CCR impoundment. The access pathway and working platform was constructed using shallow mass mixing with cement at the CCR surface to address safety concerns related to the geotechnical behavior of CCR. This paper describes the data from the instrumentation system which was implemented to monitor the geotechnical performance of the CCR during the pilot study. The instrumentation system included monitoring of the ground movement, vibration, and porewater pressure within the ash delta of the CCR impoundment during a pre-construction load testing, equipment mobilization over the access pathway, and DSM column installation over the working platform. INTRODUCTION A deep soil mixing (DSM) pilot study was conducted at a coal combustion residual (CCR) surface impoundment to evaluate mix designs and construction techniques for the regulatory closure. The DSM columns will create a wall which will separate and retain the CCR in a consolidated footprint separate from the closure by removal portion of the footprint and provide a barrier between the two areas of the surface impoundment. Historically, the surface impoundment received CCRs including fly ash, bottom ash, boiler slag, and gypsum, along with other byproducts produced from flue gas desulfurization (FGD). The predominant CCR in this impoundment were fly ash and bottom ash. The primary goals of the DSM pilot study were to assess the mix design strengths and to evaluate DSM construction techniques that could reach the design mixing depths of up to 90 ft. The DSM test columns were installed on the CCR delta approximately 500 ft from the nearest impoundment dikes. Another objective of the pilot study was to develop, construct, and monitor an access pathway for safe passage and movement of construction equipment on the CCR delta.

Jan 1, 2019

By Stuart Coutts

"This paper presents an overview of the author’s experience related to the assessment of the base capacity of straight shafted and enlarged-base bored piles in sand. A design approach based on CPT qc is described which has been calibrated using a database of load tests. The importance of correct installation techniques with instrumentation are illustrated and a discussion is presented on the current use of high strain dynamic testing to validate compliance with design. An example of a recent project with high quality instrumented load test data illustrates the close match to the proposed best practice approach and also highlights the importance for consideration of the effects of stress relief for deep foundations installed in deep excavations.1 INTRODUCTIONContinuous Flight Auger (CFA) piles are the bored foundation pile of choice for sand deposits across Australia. The evolution of the determination of the base resistance of CFA piles has been shaped by available investigative techniques, calculation methods, and calibration of designs with laboratory and field testing. The Cone Penetration Test (CPT) has been widely used in Western Australia (WA) where the test has been commercially available via multiple contractors for more than 25 years. On the East coast, the adoption of CPT testing has been slower with a transition from traditional Standard Penetration Testing (SPT) still occurring. Dynamic pile load tests are often used to derive parameters. The influence of pile installation on performance is commonly misunderstood and is an important element on any discussion of pile capacity for CFA pile types. The interface between the base of the constructed pile and the in-situ soil has an influence on capacity such that a poorly constructed pile base will have limited (if any) contribution to pile performance within the normal working range, generally within a 10 mm movement. The research presented in this paper pertains to CFA piles (no drilling fluids) and enlarged base piles constructed using CFA techniques under drilling fluids such that clean pile/base interface is targeted. Developments in modern piling equipment and instrumentation allow the pressure and volume of delivered concrete/grout to piles to be accurately monitored at various stages of installation such that repeatable ‘best practice’ can be achieved. The changes in soil conditions that occur due to the disturbance of the install technique are also important.Although the results of this research are likely applicable to bored piles, the interface between the pile and in-situ soil (shaft and base) need to be considered for various installation techniques. The effects of stress relaxation (due to removal of soil above pile base and adjacent shaft), time to concreting, and the zone of disturbed soil around the pile shaft are paramount.2 INSTALLATION CONSIDERATIONS The pile mix (concrete/grout) and interface with the in-situ soil are also an important consideration. For example, coarse grained, poorly graded, dry, clean sand will be partially permeated by most pile mixes; such that the influenced soil will be enhanced and in instances the overall effective pile dimensions increased. Permeation of the disturbed zone of a pile or anchor shaft along with scale effects (Lehane 2009) can have significant effect on shaft capacity and shaft frictions significantly exceeding expected are not uncommon based on ‘theoretical’ dimensions. Advancements in mix technology and mix techniques also have a large influence on the pile/soil interface. The ability of the piling rig and augers to excavate a plumb and gauge hole can also have a large influence on the zone of soil disturbed adjacent the constructed pile with a resulting influence on capacity."

Jan 1, 1900

By Patrick van der Schaaf

"During 2016, foundation piling works were completed to allow for the construction of a production and storage/handling terminal in Rotterdam. It is there that steel foundations will be produced for offshore wind farms and the oil and gas industry. Several Dutch contracting companies were involved in constructing: foundations for an assembly hall, a barge quay and a deep-sea quay wall. For the hall foundations, cast in situ concrete vibro piles were created. Open ended steel casing piles were also installed due to very high cone resistances which made it impossible to perform cast in situ piles in certain areas. The quay wall was constructed with open ended steel casing piles in combination with sheet piles. A deep-sea quay wall was also constructed to provide enough storage area for the offshore mono piles. This project was unique and challenging due to the use of different foundation technologies in challenging circumstances and soil conditions. This paper will give an insight into the Dutch use of varying foundation piling techniques for deep-sea quay wall constructions. It can be concluded that even experienced local contractors can be surprised by variations in soil conditions. It will also show how the contractors adapted to the difficult circumstances.PROJECT OUTLINEThe project consisted of a barge quay near the assembly hall with a length of 500 metres, width of 42 metres and a height of 35 metres, and a deep-sea quay wall 480 metres in length. This paper concentrates on the foundation works for the construction of the deep-sea quay wall. The construction of the deep-sea quay wall consisted of a combination of open ended steel casing piles with a diameter of Ø 1420 mm and a wall thickness varying between 21 and 23 mm. The lengths of the steel casing piles varied between 32 and 37 metres. Between the steel casing piles triple PU 28 sheet piles were installed with lengths varying between 26 and 29 metres. In the Netherlands, a combination of open ended steel piles and sheet piles is known as a “combi wall”. For the deep-sea quay wall a steel combi wall was shored with steel H- section profiles that were driven in a raked position whilst being injected with grout, so called MV-piles. The MV piles for this project consisted of steel HEB 600 sections with lengths from 52 up to 59 metres and were installed with angles varying between 42.5 and 47.5 degrees. For a detailed overview regarding the project specifications reference is made to table 1 which is presented below."

Jan 1, 1900

By Andrew Middleton, Mick Stadter, Chris Crowe, David Chong

"The Level Crossing Removal Project – Package 1 is part of the Victorian Governments commitment to remove 50 of the most dangerous and congested level crossings across Melbourne. This involved removing three crossings on the Frankston Line in the south east suburbs of Melbourne. The works involved replacing approximately 2.5km of at grade track with three rail cuttings up to 8 m deep at each of the bridges that replace the level crossings. The cuttings are retained by piled retaining walls and during the main construction occupation approximately 250,000 cubic metres of soil was removed. The project has presented significant geotechnical challenges due to the location in residential suburbs and tight rail corridor and rail occupation timeframe. These challenges included temporary and permanent wall stability, foundations, earthworks and dewatering. As a result, careful design and innovative construction techniques have been necessary to limit impacts on the community and meet the project timeline.INTRODUCTIONThe Level Crossing Removal Project – Package 1 is part of the Victorian Governments commitment to remove 50 of the most dangerous and congested level crossings across Melbourne. This involved removing three crossings on the Frankston Line where it crosses North Road in Ormond, McKinnon Road in McKinnon and Centre Road in Bentleigh.The project involved replacing approximately 2.5km of at grade track with three rail cuttings up to 8 m deep at each of the bridges that replace the level crossings. The cuttings will accommodate three lines of rail tracks with the cuttings up to 25 m wide. The cuttings are retained by piled retaining walls and during the main construction occupation approximately 250,000 cubic metres of soil has been removed.The project presented significant challenges due to the location in residential suburbs and tight rail corridor and rail occupation timeframe. As a result, careful design and innovative construction techniques have been necessary to limit impacts on the community. The geotechnical challenges generally fell into one of three areas, earthworks, structures and groundwater. The primary earthworks challenge for the project was moving the 250,000 cubic metres of soil in a 10 day window, however, from a geotechnical viewpoint, obtaining a stable subgrade on which to operate the necessary construction plant in a short time frame with constrained site access and time to import materials was the key. Whilst closely watching the performance of the dewatering system, a range of contingency plans were developed to cope with any difficulties."

Jan 1, 1900