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By Arturo Ressi di Cervia

Construction of the drilled shafts for the Brightman Street Bridge Replacement Project were not only challenging due to working over the water but were also challenged by changed soil conditions, concurrent work being performed by an adjacent contractor on the same project, environmental restrictions and severe winter conditions. A total of 36 x 8 feet diameter drilled shafts with 7.5 feet rock sockets were installed for the East and West bascule piers. This project also included Osterberg Cell load testing on two production drilled shafts at each the East and West bascule piers. The results from the load test program were used to fine tune the design of the drilled shaft rock sockets. From a constructability standpoint the reverse circulation drilling method with a pile top drill rig proved to be an excellent choice for drilling the overburden and rock sockets of the large diameter deep drilled shafts.

Jan 1, 2003

By Dinesh R. Katti

Caissons which are locally known as well foundations, which may very in diameter from 30 m to more than 30 m and in majority of the cases having depth to diameter ratio between 1 to 1.5, are normally used to support piers of long span bridges or tall structures, which transmit high magnitude of axial load, horizontal thrust and moment. On the basis of depth to diameter ratio the foundation system appears to fall in the category of shallow foundations but due to deep excavation, it is observed that part of the moment acting on the caisson is shared by due the sides due to development of passive resistance. The problem is statically indeterminate and three dimensional in nature. To ascertain the various parameters needed for design, such as moment shared by base and sides, horizontal and vertical displacement and tilt, and base and side contact pressure diagrams need to be obtained from nondimensional relations of parameters with respect to D/B ratio derived from large scale model studies conducted by Katti etal at IIT, Bombay under MOT Project between 1976 and 1988 and later on at UNEECS. On the basis of above data on attempt is made to put forward guide lines for selection of parameters for design of caisson foundations / well for following cases for opening us some discussion. The cases are cohesive soil at the side and cohesive soil, or sand or soft rock or hard rock at the base.

Jan 1, 1996

By Christian L. Escalera

Over seven years ago, on October 29, 2012, Superstorm Sandy pummeled the Northeast of the United States inflicting heavy damage on New York City Transit’s (NYCT) system. Since then, NYCT has been methodically rehabilitating and hardening its assets to upgrade service and prevent future impacts caused by similar devasting storm surges. Part of these resiliency efforts, NYCT’s 207th St Yard Project is one of many projects that make up the Sandy Repair and Flood Mitigation Program. The work to be performed on the 207th Street Project includes building a perimeter Floodwall along the Harlem River, extending up 215th Street and 9th Avenue with the intent of having the ability to withstand a 500 Year Storm flooding event. The original 1,535 lineal feet of the marine side floodwall design consisted of 937 each W40x235 H-Piles continuously welded to PS 27.5 flat sheet to form an interlocked and composite steel seawall that would protect the NYCT 207th Yard from a storm surge of the Harlem River. However, after the Contract was awarded and a Notice to Proceed was issued, Walsh Construction Company II (WCCII) partnered with Mueser Rutledge Consulting Engineers (MRCE) to propose a redesign of the marine wall section as a Value Engineering Change Proposal (VECP). This VEP redesign is comprised of 279 each 54in Diameter Steel Pipe Piles that are interconnected with continuously welded PZ 35 sheet piles interlocks. The intent of the VEP was to provide a cost savings that could be shared by both parties as well as alleviate some constructability and alignment control concerns that WCCII had expressed to NYCT. The VEP allowed WCCII to substantially lower the total cost which was shared between NYCT and WCCII.

By Onur Guvener, Kalaiarasi Vembu, C. Vipulanandan

"Installation procedure and the quality of the material used in the construction have significant effects on the behavior of the Auger Cast in Place (ACIP) piles. In this study, Installation and curing of a 760 mm (30 in.) diameter and 12 m (39 ft) long ACIP pile with a design capacity of 1140 kN (128 tons) in hard clay was investigated. Construction quality was monitored using the automated monitoring system where the volume of grout pumped and the pressures were monitored with depth. The curing of the pile was monitored using axial vibrating wire strain gages at four levels and lateral vibrating wire strain gages at two levels. The residual strain and temperature profile in the curing pile was monitored over a period of week to determine the appropriate time for load testing the pile. Axial behavior of Auger Cast in Place (ACIP) Piles in hard clay was studied using full scale load test on an instrumented pile. The load-settlement and load transfer relationships of the pile was investigated based on the load test results. Development of skin friction in the load test pile and the reaction pile was also investigated.INTRODUCTIONAugered cast-in-place piles (ACIP) are drilled foundation installed by drilling a hole with a continuous flight auger to a predetermined depth. Non-displacement Augered Cast-in-Place (ACIP) piles are increasingly used for supporting building, bridges, sound barrier walls and many other structures around the world. In an ACIP pile, depending on the soil type and rate of the auger advance, ground stresses are maintained near the value that existed before construction by using a continuous flight auger, which is never withdrawn until the cementitious material (fluid Portland cement grout) is placed by pumping the grout beneath the withdrawing auger under pressure through the hollow stem of the auger (Vipulanandan, 2005). ACIP piles are typically installed with diameters ranging from 0.3 to 1.0 m and lengths up to 30 m (Brown, 2005) although longer lengths have occasionally been installed. Comparing to the drilled shafts and driven piles of equivalent size ACIP piles can be installed more rapidly with fewer disturbances to the surroundings in favorable geological conditions. Hence the installation procedure and the quality of material used in the construction have significant effects on the behavior of ACIP piles (Vipulanandan, et al. 2007). In this paper construction quality control technique for ACIP piles was investigated. Load displacement and load transfer behavior of pile in compression and tension in hard clay was also studied. The development of side resistance in compression and tension for the load test piles and the reaction pile were also investigated."

Jan 1, 2017

By Guo H. Lei

Over the last four decades, barrettes have been ever-increasingly adopted as the foundations for tall buildings and heavy infrastructure projects all over the world. Many findings have been gained from practical applications and theoretical researches. In this article, a collection of literature is reviewed on the installation effects and load-carrying behaviour of barrettes derived from field and laboratory tests and theoretical studies. It covers many aspects, such as the ground deformations and stress changes caused by the installation of barrettes, the shaft resistance mobilisation behaviour, the construction effects on the shaft resistance, and the effects of pile spacing, pile shape and pile group layout on the load-carrying behaviour of barrettes.

Jan 1, 2006

By Mu Chen, Ye-Shuang Xu, Dong-Wei Hou, Shui-Long Shen, Huai-Na Wu

"This paper presents a laboratory investigation on the mechanical behaviors of the cement-clay admixture improved by polypropylene fiber. Cement can significantly improve the clay admixture. The fiber additive also improves the strength and ductility of the improved clay. The Unconfined Compression Strength (UCS) of the polypropylene fiber-reinforced cement-clay presents an overall trend to grow with the increase of fiber length. The improved clay reached its peak strength at the fiber content of 0.5%. Then the UCS of the improved clay will slowly reverse if the fiber content continues to rise. For study of curing time, improved clay behaves better in its early strength, but an inhibition will be brought about if fibers are excessive.INTRODUCTIONGround improvement technology is essential for construction of structures in soft ground. Some traditional techniques often cost much but result in little. For instance, along the coastal region of China, soft ground is often improved by backfill with high quality sandy soil transported far away, leading to high additional haulage costs and long construction period. Reutilizing the excavated soil as backfill or subgrade after treatment, by contrast, will be more economical and effective (Hufenus et al., 2006). Many researches have been conducted to improve the compression strength of soft soil, among which, the method of mixing the soft soil with cement and fly ash is one of the most common ways (Kolias et al., 2005; Horpibulsuk et al., 2009; Porcino et al., 2012). It is known that soil resists well against compression and shear force but behaves poorly in resistance to tension. Therefore, utilizing tensile elements such as fibers and strips to improve the tensile strength will be effective because of its strength isotropy, better durability and cost effective (Haeri et al., 2000; Kaniraj and Havanagi, 2001; Consoli et al., 2010)."

Jan 1, 2015

By P. H. Derbyshire

The use of continuous flight auger piles has increased significantly in the U.K. to such an extent that it is now the most widely used method of constructing small diameter bored piles. This paper describes the improvements in equipment, techniques and particularly monitoring that have led to this growth. A review of the equipment in use describes how purpose built self erecting machines have been generally adopted. Improvements in ancilliary equipment are described. Concrete has almost completely replaced grout and techniques have been developed to extend the length of reinforcement that can be placed. Leading specialist contractors have developed instrumentation to monitor the construction of the pile (in terms of time, depth, torque, concrete pressure and flow) and keep a record for checking. A further significant development of this monitoring by means of sensors at various levels in the auger stem is described. The results obtained from this monitoring are reviewed and future developments discussed.

Jan 1, 1989

By Peter Jackson

The dewatering of the large construction pits required for major infrastructure projects often has a significant impact on the environment. This is particularly so in urban areas and where groundwater resources are of interest. These environmental impacts are inter alia, groundwater lowering and the consequent effects such as settlement and deterioration of timber foundations, together with the impact of the dewatering on the groundwater quality. In order to minimise the environmental impact of the dewatering, the quantity of water to be abstracted and the amount of groundwater lowering in the surrounding area must be minimised. This paper describes the measures that have been taken on the Copenhagen metro project to achieve the objective of minimal environmental impact whilst still carrying out a major dewatering scheme.

Jan 1, 2000

By Sherrill Gardner

Vibratory drivers have been used since the 1930s to drive and extract piles. Vibratory pile drivers have the capability of significantly decreasing pile installation time, especially in granular type soils. However, they have not been widely accepted because of the uncertainty in estimating the bearing capacity of the driven pile. When driving bearing piles, the industry standard method for obtaining load carrying capacity of a pile installed with a vibratory driver is to redrive with an impact hammer. The advantage of improved productivity is lost with the redrive procedure. Currently, there is no other method to predict the capacity of these bearing piles installed with a vibratory driver. The Naval Civil Engineering Laboratory (NCEL) is making progress towards being able to estimate the bearing capacity of these piles. This paper describes field testing and corresponding analytical modeling of the vibratory driver-pile-soil system. The following sections describe the development of the numerical model and techniques for collecting field data. A discussion of the prediction of the pile driving process based on field test data is followed by suggestions as to the additional work that should be done to further verify the model to a point where it can be used with confidence.

Jan 1, 1987

By Mohammed Sakr

The use of helical piles as a deep foundation option has considerably increased in the recent years to support a variety of loads, from small loads for several applications such as residential housing, solar farms, utilities and retrofit projects, to large loads for many applications such as commercial, power transmission lines, oil facilities and industrial applications. Therefore, it is necessary to qualify and quantify their axial capacities and performance characteristics. This paper presents the first full-scale axial compression and tension (uplift) testing program executed on large capacity helical piles installed in cohesionless soils. A total of eleven pile load tests using either single or double-helix piles with shaft diameters that varied between 324 mm to 508 mm (12¾ in to 20 in) were carried out, including seven axial compression tests and four tension (uplift) tests. The results of the axial compressive and tensile pile load tests as well as field monitoring data of helical piles installed in dense sand are presented in this paper. Based on the results of this study it was found that helical piles have developed significant resistance to axial compressive loads up to about 2920 kN (656 kips) and tensile loads up to 2900 kN (652 kips).

Jan 1, 2011

By A. David Miller, Douglas M. Barber

"The Rocky Mountain Arsenal was used by the military to produce chemical warfare agents and incendiary munitions for use during World War II and later by private companies for the production of industrial and agricultural chemicals. After an investigation performed in accordance with CERCLA confirmed significant levels of contamination due to the common industrial and waste disposal practices of the era and the discovery of over 300 species of wildlife inhabiting the land the Rocky Mountain Arsenal became a wildlife refuge and contamination cleanup efforts began. Three lime basins originally used to treat wastewater from the chemical production were decided to be contained in place, requiring a seepage barrier installed around the perimeter of the site to further prevent groundwater/contaminant migration. This case study will discuss the successful installation of a soil-bentonite cutoff wall around the area using deep soil mixing. Highlights of this case study will also include a discussion of the challenges faced due to construction activities performed with Level B Hazmat PPE requirements as well as added challenges brought on by the Winter season, after the project was delayed due to a positive air monitor detection for the chemical weapon Lewisite during construction of the work pad.INTRODUCTIONThe Rocky Mountain Arsenal (RMA), located just outside of Denver, Colorado, was established by the United States Army in 1942 to produce chemical warfare agents and incendiary munitions for use during World War II. Following the war, and as weapons production decreased, portions of the site were leased to private companies for the production of industrial and agricultural chemicals. The principal lessee, Shell Oil Company, manufactured mostly pesticides at RMA facilities from the early 1950s to the early 1980s.In 1984 an investigation began in accordance with the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and confirmed significant levels of contamination due, in large part, to the common industrial and waste disposal practices of the era. It was also discovered that over 300 species of wildlife inhabited the land in the absence of regular human activity, including a group of bald eagles, leading to the passing of the Rocky Mountain Arsenal National Wildlife Refuge Act in 1992."

Jan 1, 2015

By Hyung-Min Kwon

There are a number of methods available that can be used to estimate the bearing capacity of piles that are subject to lateral load, such as the theory of subgrade reaction or the elastic continuum approach. The objective of these approaches is to determine the lateral load corresponding to the allowable lateral displacement of the pile. It is important to select the appropriate soil stiffness when analyzing soil behavior within the allowable displacement of piles because the stiffness of soil is dependent on the displacement of piles. Even though pressuremeter tests can measure the stress-strain behavior within a wide strain range, pressuremeter test results have been utilized to assess only the fragmentary soil modulus based on either semi-empirical correlations or analytical approaches. This study is concerned with a methodology that can estimate the horizontal deformational property, while taking into consideration the nonlinear deformational characteristics of sandy soils. Pressuremeter tests were conducted for 15 cases using a calibration chamber. Reloading curves were employed in the estimation of horizontal deformational property in order to minimize the effect of soil disturbance caused by the installation of the probe. The shear modulus degradation characteristics were estimated from the curve fitting for the reloading curve and from extrapolation using the exponential function. In addition, the difference was taken into account between the stress state around the probe in reloading and that of the in-situ state. A consistent relationship was observed between the maximum shear modulus taken from the suggested method and the bender element tests performed in the calibration chamber, simultaneously with the pressuremeter tests. In addition, the results showed significant concurrence with the well-known empirical correlation.

Jan 1, 2008

By Robert Bachus, Jamey B. Rosen

"Abstract Large scale In Situ Barrier Wall Construction projects, specifically those related to earth dams, dikes, and levees, frequently require stringent quality control measures to ensure the success of the wall. This presentation discusses the applications of Geographic Information Systems (GIS) technology to capture information from multiple data streams and provide geotechnical feedback, quality control, and project control feedback. Techniques used to geospatially analyze verticality data from secant piles and panels will be demonstrated. Examples will be presented from barrier wall installations at two sites owned by the U.S. Army Corps of Engineers (USACE): the Wolf Creek Dam in Kentucky, and Center Hill Dam in Tennessee.IntroductionDeep foundation installations require contractors to collect a substantial amount of information over the course of a project, both for internal quality control of construction progress and for demonstrating compliance with customer or owner specifications. Methods of collecting information are constantly improving, bringing with it the need for a systemic approach to managing the increasing amounts and types of data. Handling these diverse types of data presents challenges with both budget and schedule demands. This paper discusses some techniques for adding or increasing quality control in barrier wall constructions by consolidating, visualizing and analyzing data using relational database and Geographic Information Systems (GIS) technology, collectively referred to as Information Management System (IMS) development. The IMS concept is designed to facilitate the collection, transfer and processing of data and provide an easy way to remotely access and visualize construction progress.The remainder of this paper presents the needs and objectives of an IMS applied to quality control in barrier wall construction, the components and data flows involved, the capabilities and user interfaces of the systems and the benefits for the end users. Examples are presented throughout from case study projects including: a pile barrier wall applied in the rehabilitation at the Wolf Creek Dam in Kentucky (under contract to the Treviicos-Soletanche Joint Venture), and a secant pile barrier wall currently under construction in the rehabilitation of the Center Hill Dam in Tennessee (under contract to Bauer Foundations Corporation) (both owned by the Nashville District of the USACE)."

Jan 1, 2014

By Mohamed A. Mansour, Ahmed M. Soliman, M. H. El-Naggar

"Grouted helical piles allow significant increase in pile capacity with low additional cost over that of conventional helical piles. They can be particularly advantageous in sites where installation disturbance can reduce or even eliminate the pile shaft resistance. For helical piles with slender shafts, a grout column offers increased buckling resistance under compression loading, and may reduce the potential settlement required to mobilize the bearing component of their plates. This paper investigates the performance of grouted helical piles installed in loose sand. Grouted helical piles were constructed and tested in a controlled laboratory environment. Helical piles with hollow pipe shaft and single helix were grouted during installation. The grout was injected into the soil under high pressure through two nozzles placed above the piles helices. The load test results showed significant improvement in the performance and load carrying capacity of the helical pile due to the formation of a cylindrical grout column along the entire shaft leading to a higher shaft resistance contribution to the total pile capacity. The results suggest that grouted helical piles with slender hollow shaft could be used to support large structural loads. INTRODUCTIONHelical piles are widely used as a deep foundation system for different engineering applications. They represent an attractive foundation option because of their cost effectiveness, ease of installation even in limited access areas, low levels of noise and vibrations, and their ability to be installed through ground water without casing. In addition, they allow immediate loading upon installation. Helical piles are installed into the ground by applying a mechanical torque to the pile head. The installation torque monitoring provides a kind of quality control during the construction of helical piles. It could be used in predicting the ultimate pile capacity using several capacity-torque correlations (Livneh and Elnaggar 2008; and Hoyt and Clemence 1989).However, helical piles installation can cause soil disturbance within the annular zone affected by the pile helices. This disturbance can introduce fissures within the pile cylindrical failure surface (Vesic 1971; Mooney el al. 1985; and Zhang 1999). Thus, the shear strength of the soil decreases along the affected zone. Bagheri and El Naggar (2013) evaluated the installation effects of helical piles in sand. They reported that as the helical blade proceeds into the ground, sand within the cylindrical path circumscribed by the helices experiences torsional and vertical shearing accompanied by sand displacement and stress changes. This process is more pronounced in the case of multi-helices and large diameter anchors. Bagheri and El Naggar (2016) evaluated the installation effects of helical piles in structured clay. They indicated that the behavior of the helical pile and its capacity are significantly affected by the degree of soil de-structuring induced by the penetration of the pile shaft and helices. In addition to the installation disturbance, helical piles have other drawbacks including; high potential settlement required to fully mobilize the bearing component of their plates, low buckling resistance of their slender shafts, and the incomplete rigidity of the coupling joints along the pile shaft that allow some lateral movement under compression loading (Vickars and Clemence 2000)."

Jan 1, 2016

By S. Kanai

Nodular piles is to be piles provided with several nodular projections along the pile shaft, as shown in Fig. 1. Nodular piles are usually installed through either driving method with hammer or preboring method. This paper presents that the bearing capacity installed through each method is considerably higher than that of cylindrical pile without nodules. This paper also proposes the statistically analyzed unique formulae of the bearing capacity of nodular piles.

Jan 1, 1989

By Saieb Haddad, Henry Pate

"Building retaining walls in an urban area is becoming more difficult due to right-of-way restraints. Using standard concrete cantilever walls requires a construction easement behind the walls for installation, which for the most part is unavailable. To install these types of walls in a limited right-of-way requires extensive temporary walls to minimize the construction easement. Top-down construction walls utilizingtie-back anchors for support require either the purchase of the right-of-way or underground easements in the area of the anchors.These problems faced the Department on Interstate 75 widening in Knoxville, TN in an area of a large cut. A multi-story Insurance Building and a large commercial Retail Center were located at the top of the cut. To prevent any impact on the buildings, the walls had to be placed within a limited area. The option of buying the properties was prohibitively expensive. Due to the height of the two walls and the variability of the underling rock line, contiguous caisson pile cantilever walls were contemplated as the only wall type that would be appropriate. The cost of the two walls was estimated to be very close or even higher than the cost of purchasing the two buildings. The Department believed that there must be a better way to deal with the problem. A vertically tied-down pile frame wall constructed from the top-down with a concrete facing was developed. This allowed the construction of the walls to be restricted to the available limited area and provided substantial savings for the State.INTRODUCTIONThe widening of I-40/75 has been a major transportation project in the Knoxville area which is being constructed by the Tennessee Department of Transportation. The project includes 18 Retaining Walls and 13 Bridges.Two of the 18 Retaining Walls, refer to Figure 1, are to support two valuable properties, one being an insurance company housed in a multi-story office building and the other a suburban shopping center which were appraised at $13.0 million and $5.0 million respectively. Due to the 31 ft. (9.5m) maximum height of each of the two Retaining Walls and the limited Right-of- Way of 15.0 feet (4.6m), a contiguous caisson pile cantilever wall was proposed for each of the two retaining wall sites with an estimated cost of $12.0 million each. The contiguous pile cantilever Wall is comprised of a line of caisson piles socketed into underlying competent bedrock. The design required that 4 ft. (1219mm) dia. piles be installed at 6 ft. (1.83m) centers, socketed into rock in order to provide lateral stability and restrict lateral wall movement to acceptable limits. The line of caissons would be fronted with a cast-in-place concrete face wall"

Jan 1, 2007

By Saieb Haddad, Henry Pate

"Building retaining walls in an urban area is becoming more diffi cult due to right-of-way restraints. Using standard concrete cantilever walls requires a construction easement behind the walls for installation, which for the most part is unavailable. To install these types of walls in a limited right-of-way requires extensive temporary walls to minimize the construction easement. Top-down construction walls utilizing tie-back anchors for support require either the purchase of the right-of-way or underground easements in the area of the anchors.These problems faced the Department on Interstate 75 widening in Knoxville, TN in an area of a large cut. A multi-story Insurance Building and a large commercial Retail Center were located at the top of the cut. To prevent any impact on the buildings, the walls had to be placed within a limited area. The option of buying the properties was prohibitively expensive. Due to the height of the two walls and the variability of the underling rock line, contiguous caisson pile cantilever walls were contemplated as the only wall type that would be appropriate. The cost of the two walls was estimated to be very close or even higher than the cost of purchasing the two buildings. The Department believed that there must be a better way to deal with the problem. A vertically tied-down pile frame wall constructed from the top-down with a concrete facing was developed. This allowed the construction of the walls to be restricted to the available limited area and provided substantial savings for the State. INTRODUCTIONThe widening of I-40/75 has been a major transportation project in the Knoxville area which is being constructed by the Tennessee Department of Transportation. The project includes 18 Retaining Walls and 13 Bridges. Two of the 18 Retaining Walls, refer to Figure 1, are to support two valuable properties, one being an insurance company housed in a multi-story offi ce building and the other a suburban shopping center which were appraised at $13.0 million and $5.0 million respectively. Due to the 31 ft. (9.5m) maximum height of each of the two Retaining Walls and the limited Right-of- Way of 15.0 feet (4.6m), a contiguous caisson pile cantilever wall was proposed for each of the two retaining wall sites with an estimated cost of $12.0 million each. The contiguous pile cantilever Wall is comprised of a line of caisson piles socketed into underlying competent bedrock. The design required that 4 ft. (1219mm) dia. piles be installed at 6 ft. (1.83m) centers, socketed into rock in order to provide lateral stability and restrict lateral wall movement to acceptable limits. The line of caissons would be fronted with a cast-in-place concrete face wall."

Jan 1, 2007

By Kaushik Mukherjee

"Malaysian offshore and surrounding region are favorable to the installation of driven piles. During the design phase, pile driveability analysis plays a major role in pile make-up design to suit and selection of the feasible hammer, besides defining acceptance criteria to ensure a certain level of confidence of its fitness for purpose. The accuracy level of driveability analyses depends substantially on the selection of its parameters that best represent the in-situ scenario. The most uncertain of the parameters are those related to the soil model. It is noted in various projects in the region, that the consideration of suitable soil resistance to driving, coupled with soil dynamic parameters, significantly affects driving sequence planning, design, material, hammer selection and most importantly pile acceptance criteria. This is particularly relevant for a region that contains predominantly clayey subsoil resulting in large diameter, long friction piles susceptible to driving disturbances and slow strength recovery. Various researchers suggested suitable dynamic parameters and soil resistance during driving calibrated to specific regions. Regional experience suggests a set of soil degradation and parameters to suit the different stages of driving which is corroborated by pile monitoring records during continuous and delayed driving scenarios. The most sensitive amongst all dynamic soil parameters is the skin damping in clay. Smith’s wave theory approach considers a conservative assumption in selecting the parameters in absence of site-specific data, while a different approach may be adopted based on consistency of the clay for a site where the geotechnical parameters are well defined. This paper summarizes some independent studies on the effects of variations in dynamic parameters and resistance at different stages of driving and suitability of choices of different pile make-up and hammers for an optimum design. Similar experiences, coupled with simulation studies and back-analyses of available driving records suggest a reasonable judgment for the region.INTRODUCTIONFixed structures are generally supported in the in-place condition on a pile foundation those may either be driven or drilled & grouted piles depending on the subsoil. The piles may be driven inside the jacket legs or drilled through individual skirts normally grouped in clusters at the base of each leg. The types of subsoil dealt with in the Peninsular Malaysia and Gulf of Thailand surrounding region are conducive to the installation of driven piles only. The design of an offshore pile is fundamentally the optimization of pile length, size and make-up those are suitable to the requirement and supply. An interactive effort combining aspects related to geotechnical, structural and constructability are required to converge into a feasible, safe and economic solution. Other than the checking of the installation feasibility using a set of hammers in a given environment, driveability analysis is also used to define acceptance criteria for a majority of the offshore piles. Unlike short and end bearing piles in sand/soft rock, the piles in clayey subsoil regime often could not be rested on a dense strata where it could be met by a definite set criteria. Usually a measurement of blow counts determined and defined by driveability analyses forms the acceptance criteria to ensure a certain level of confidence of its fitness for the purpose coupled with an optimum penetration. While softness and uncertainty of the soil strata at target penetration may be resulted in possible overdrive, an unusual delay or the presence of an unidentified cemented layer or a boulder may cause early refusal or underdrive scenario. Hence, accuracy of the investigation, driveabilty study as well as the precautionary measures to avoid delays during driving are of equal importance."

Jan 1, 2015

By James P. Stewart

This case history describes the engineering design and construction for the Contractor of a 35-ft-deep excavation for an 800-square-foot addition to an existing sewage pump station. The site posed unexpected geotechnical complications that included deep gravelly soil, a history of local construction difficulties, groundwater consisting of heavy salt brine, and the need to underpin the existing pump station. The project took an interesting twist when the Owner issued a change order limiting the dewatering discharge to a fraction of that required to lower the water table. This documents the interesting circumstances of this job and documents the unusual subsurface conditions in the Syracuse, NY Lakefront area.

Jan 1, 2003

By Wesley Schmutzler

The Deep Mixing Method (DMM) was employed to raise and support the LPV (Lake Pontchartrain and Vicinity) -111 Levee in New Orleans. Even using innovative technologies, the tight schedule to achieve the 100 year elevation by June 1, 2011 was a daunting endeavor. The size and scope of DMM proposed for LPV-111 was on a scale never attempted outside of Japan. Over 1.65 million cubic yards of DMM was installed. LPV-111 is adjacent to the Bayou Sauvage Wildlife Refuge, which is the largest urban National Wildlife refuge in the United States. By utilizing DMM to control settlement and improve stability of the taller levee, side slopes were steepened from the conventional 1V:4H to 1V:2.85H, thus avoiding encroachment into the Bayou Sauvage and reducing the amount of clay needed for the completed levee. The COE utilized Early Contractor Involvement (ECI) for this contract. The ECI process allowed for input from the DMM contractor, TREVIICOS South, in order to optimize equipment resources and material requirements. This paper gives an overview of the extensive DMM requirements for LPV-111 and explains the benefits of the ECI process.