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By Michael T. Lambert

The purpose of the this paper is to demonstrate the benefits of using additional instrumentation during load tests of auger-cast-in-place piles. Traditionally, only load and butt displacement are determined during load tests. The results from and methods used to instrument 15 auger-cast-in-place (ACEP) piles as part of six projects are included herein. By instrumenting the piles, the distribution of load along the pile length and load transfer can be determined, allowing the pile capacity to be adjusted or the length/diameter of the pile to be adjusted for the a given required load. The majority of the piles tested were designed as end bearing piles on either shale or limestone bedrock. No discussion of Geotechnical Instrumentation can be started without acknowledgement of the "Red Book." The actual title of the book is Geotechnical Instrumentation for Monitoring Field Performance, by Mr. John Dunnicliff, John Wiley and Sons, 1993. Anyone undertaking an instrumentation program should thoroughly review the Red Book, paying particular attention to Chapters 3 and 4. Instrumentation should not be done just because it can be done. There must be an unanswered question or questions that can be answered with measured data before instrumentation should be considered.

Jan 1, 2000

By Jeff Wilkinson, Brandon Walter

"A&N Electrical Cooperative provides electrical service to the counties of Accomack and Northampton along Virginia’s Eastern Shore and to Smith Island in Somerset County, Md.A&N recently worked to improve the efficiency of power distribution to a small island community and marina on Tangier Island in the Chesapeake Bay. This improvement consisted of upgrading the existing distribution substation with a new 25 kV 2-bay box distribution structure. Earth Contact Products (ECP) collaborated with PowerServices, Inc. (PSI) to design and install a helical foundation support system as part of the substation upgrade. Feasibility EvaluationThroughout the design process, A&Nworked with its partners PSI (design) andT&D Solutions (installation) to identifycost-effective alternatives. Foundationsystems considered included cast-in-placereinforced concrete caissons, precastconcrete foundations, driven steel piles and helical piles. In evaluating all of theoptions, the greatest concern was gettingthe material onto the island, followedclosely by the availability of the equipmentto install the foundations. Clearly, cost,more specifically the installed cost, was asignificant consideration and decisionfactor throughout the process.There were several limiting factors that had to be considered during the design process, the most significant of which was that all of the material had to be barged to the site. With traditional reinforced concrete deep foundations in mind, the cost for installing these piles was projected to be nearly $2,000/cu yd ($262/cu m) of installed concrete. Given that approximately 5 to 6 cu yd (3.8 to 4.6 cu m) of concrete would be required for this structure, the cost was significantly high for this project. What’s more, because the components of the concrete mix would have to be barged and then hand mixed on site, there was concern regarding both the time required to complete the piles and the quality of the installed concrete. For the driven pile alternative, the availability, or lack thereof, of equipment and material cost resulted in a total cost estimate that was more expensive than that of the concrete piling alternative. The high material cost for the piles, which was more than double than the cost of concrete, was due to the number and size of piles needed to resist the overturning moment. Ultimately, the team selected the helical pile alternative. The decision to a use helical pile foundation system was based on many factors, not the least of which was the remote location of the project site and the difficulties associated with getting material, equipment and construction personnel to the project site."

Jan 1, 2017

By Jack Hayes

The design and construction of deep foundations involve many uncertainties. For the designer there are uncertainties regarding soil and ground water variability, regarding sampling and lab testing, regarding analytical techniques and regarding construction technique. The latter being the uncertainty over which the engineer has least control and which may have the greatest impact on capacity. Foundations with a high design factor of uncertainty can be very costly. Foundations designed with a high factor of uncertainty may have a low factor of safety, which can be even more costly.

Jan 1, 2000

By Alan Alhadeff

Why is mediation being hailed as the wave of the future? The high cost of putting on a trial, over-crowded court calendars and long trial delays have resulted in what prominent attorneys and leading jurists are calling a litigation crisis. In no segment of the legal world are these pressures greater felt than in the trial of the serious construction case. Furthermore, the siege mentality of both the plaintiff and defense bar often leads to a reluctance by either side to make the first reasonable offer for fear of showing weakness. Attorneys operating in the serious construction case arena express concerns that there exist insufficient opportunities for the parties to meet, tell their stories, and negotiate settlement prior to the eve of trial. Mediation, by opening lines of effective communication and encouraging meaningful settlement negotiation, has proven to be a very effective antidote to the litigation crisis.

Jan 1, 1990

By Garland Likins

High strain PDA testing has become common for verification of capacity of both driven and bored piles. It is equally applicable to Augered-Cast-in-Place (ACIP) Piles. It also evaluates other aspects of the installation such as integrity. The benefit of high strain dynamic test results for the relatively low cost of the tests compared to conventional static testing has resulted in widespread use. The method is described and specific procedures for testing ACIP piles are outlined. Example results demonstrate the application.

Jan 1, 2000

By Michael W. Oakland

Weidlinger Associates was retained to evaluate the foundations supporting ten oil storage tanks at a tank farm on the east coast. The tanks were constructed over the site of a landfill which was underlain by deep organic deposits. The tanks were typically 48 ft. in height and ranged in diameter from 60 to 150 ft. The tanks were supported on both wood and steel pipe piles. After more than 35 years of service, an inspection found that up to 25 percent of the piles had separated from the mat foundation. The operations at the facility were temporarily stopped pending further investigation. Weidlinger developed comprehensive finite element models of the foundations for each tank and used random generators to conduct Monte Carlo simulations the range of scenarios of detached support conditions since it was not possible to survey all the piles below the tanks. To confirm the modeled performance and verify stability, each tank was also load tested using water with electronic instrumentation installed by Geo-Instruments. The instrumentation provided real time, web based monitoring during testing in areas which would otherwise be inaccessible during loading. Through inspection, complex modeling and sophisticated load testing, Weidlinger and Geo-Instruments were able to show that all but one of the tanks could safely be put back into service. This paper details the analysis, Monte Carlo simulations and instrumentation and load testing performed for this unique project.

Jan 1, 2009

By Matthew Janes

The RC Harris Filtration Plant, which treats the majority of the fresh water for over 2.5 million Torontonians, is a Canadian Architectural Heritage site demonstrating a classic example of Art Deco Architecture. The facility is undergoing an expansion to install an underground sludge treatment capability. Perched atop a bluff on the North shore of Lake Ontario the structure enjoys a commanding presence on the Lake Ontario shoreline. A series of underground tanks were proposed for the hillside below the structure, which when covered would preserve the building?s architectural presence. However, the plan required two, stepped excavations 12 m and 10m deep into compact, wet sands over stiff clays and clayey silts. Concerns regarding the original structure influenced designers to set the lateral deflection limit for the front footing of the existing structure at 4 mm, (0.03% excavation depth). The design-build team indicated at the time of tender that the movement criteria was unattainable using the tender design. Analysis indicated installation effects and overall elastic movement of the soil mass beneath the building would result in movements of 7 to 9 mm at the structure. Through extensive FLAC analysis and a novel construction geometry the design-build team crafted an alternative that produced significant savings over the original concept. Based upon the analysis the design-build team negotiated a new deflection criteria dictating a maximum of 2.0 mm of movement across the critical expansion joint between the Filter Building front footing and the tank slab beyond. The contractor invested in additional pre tender soils investigation to support the refined design process. The FLAC analyses indicated the Filter Building movements would be elastic and distributed up to 50 m back beneath the front footing of the structure. An extensive precision monitoring program proved construction related movements of 6 to 10 mm horizontal at the front footing. Extensometers placed at two locations over the critical interior tank expansion joint showed no measurable movements. The overall monitoring program, including inclinometers, tilt meters, tie back extensometers (smart cables) and tie back load cells indicated a good match between recorded movements and loads and those predicted by FLAC Analysis.

Jan 1, 2006

By C. O. Riggs

Geotechnical exploration in North America, in particular, exploration for deep foundations analyses, is currently and generally performed following the most basic sampling and insitu testing methods and techniques. Some would surely say that the state-of-practice severely lags the state-of-the-art. Probably more than 90% of all deep foundations, both driven piles and drilled piers, installed in North America are initially analyzed and designed, i. e. geotechnically, on the basis of either the soil penetration resistance obtained by performing the "Standard Penetration Test" (SPT), or from laboratory shear tests performed on samples obtained using 76-mm (3-in.) nominal diameter, thin wall, "Shelby tube" samplers. The use of design data obtained with other exploration methods and devices, such as bore hole pressure meters, flat plate dilatometers, even cone penetrometers, occur on the fringes of practice and often in conjunction with the use of the two simpler methods of analysis. This basic approach probably represents an attempt of the profession to use, as much as possible, common, easily understood and easily communicated procedures in all geologic environments. The characteristics of drill rigs with the required drilling and samplng tools vary somewhat from region to region in North America according to the physiography of the area of use, the types of exploration data required on a day-to-day basis, the philosophy of the engineers and geologists that use the exploration data and the financial resources of the drill rig owner. The physical capability of the exploration drill rig used on a project can have a significant effect on the quality of samples or insitu tests. The physical configuration and the quality of the drill and the drilling, sampling and testing tools not only provide the mechanical capability to obtain data but affect the attitude of the field exploration crew and the quality of work. This complete presentation is taken, for the most part, from a book in preparation for publication: "Geotechnical Exploration and Site Characterization" by C. Riggs, A. Hatheway and N. Schmidt. The book is scheduled for completion during 1987.

Jan 1, 2010

By David Sherwood

The paper has been prepared as the basis for the 2008 John Mitchell Memorial Lecture. It reviews major developments in ground engineering over the last 20 years, not from the point of view of technical processes, but from the drivers that have driven these developments and the needs that they have met. It concludes with a glimpse into the future and suggests to where current trends will probably lead us. By its nature such a review is closely aligned with personal experience and it relies heavily on case histories largely from within the writer?s own experience over that period.

Jan 1, 2008

By Les R. Chernauskas

Driven pipe piles are commonly used for near and offshore structures due to their omni-directional bending resistance, large surface area, and ease of installation. However, these piles typically cannot be driven deep enough to develop significant and sustained uplift capacity, and in some cases do not generate enough end-bearing resistance before being overstressed during driving. When driven closed-ended, their relatively light weight to cross-sectional ratio, and when driven open-ended their tendency to prematurely plug, are some installation short comings. Spin Fin® piles are traditional pipe piles fitted with flat, steel plates (?fins?) attached at a slight angle over the lower few feet of the pipe. Their design development dates back several decades for projects associated with harsh, limited weather window, offshore Alaskan oil field work. These projects required a pile type that could generate high and sustained capacity in both compression and tension, at relatively shallow depth. During pile driving, a relatively short, high capacity pile translates into more rapid installations with smaller and more efficient equipment. In this type of environment, where pile capacities are large, cyclic loading is typical, and relatively high pile movement is tolerable, the Spin Fin® pile is a superior solution. This paper describes the experience of using Spin Fin® piles on several recently completed Massachusetts Steam Ship Authority projects.

Jan 1, 2011

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 Kazuyoshi Kamimura, Masaya Kawata

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

Jan 1, 2015

By Guilherme L. M. G. Carvalho, Zachary T. Fleming

In a world of 2-dimensional design documents, envisioning and understanding 3-dimensional interferences for complex foundation construction scenarios can be challenging. Videos and computer models serve as 3-dimensional spatial aids but have drawbacks related to a fixed perspective. Augmented and virtual reality (AR/VR) provide new tools to communicate design challenges and improve construction planning. This paper provides a practical look at the basics of AR/VR systems and the tools available to the foundation design and construction industry by giving a high-level example of the technologies’ use in the design and delivery phases of a complex micropile installation project for the remediation of a dam foundation. Using these technologies, GEI was able to design and deliver a complex foundation remediation solution. AR/VR benefited regulators, and the client, to help understand the design concept, construction sequencing, and approach to overcoming installation challenges. Due to its user-friendly nature and less rigorous programming and hardware requirements, AR proved to be more useful than VR for this scenario. AR/VR will likely not replace videos and computer models; however, it can be a useful 3-dimensional visualization aid that complements the project delivery process and offers benefits that traditional methods cannot. INTRODUCTION Augmented and virtual reality is a promising and rapidly developing technology within the engineering and construction world. Like any rapidly developing new technology, the language describing it can be confusing and dynamic. To eliminate the confusion some definitions must be made. AR/ VR definitions The definitions of virtual reality (VR) and augmented reality (AR) for the purposes of this paper are as follows: VR is a computer-generated immersive environment that the user experiences within a digital 3- dimensional space (Satava, 1993)AR is a composite view created by superimposing digital objects into the user’s real-world view (Azuma, 1997). Often, VR is used in an office environment and allows the user to “visit” the digital site to review site planning, construction sequences, and interference geometry. AR can be utilized in both the office and onsite environments. Like VR, the in-office application for AR is commonly site planning. AR also can be utilized in the field for applications such as seeing through the ground to locate known existing obstructions like utilities, gas tanks, etc.

Jan 1, 2019

By Amy B. Cerato, Shawn Allred, Tatiana Vargas

"Helical piles are deep foundation elements that resemble, and are installed like, a large steel soil screw — they have a slender steel shaft with one or more round helix bearing plates welded to the shaft to provide support to the structure they hold. Helical piles are rotated into the ground with a large torque motor and provide support through soil bearing on the helix bearing plates and along the shaft. The piles are available in many lengths and, due to their small footprint along with their ability to create minimal disturbance to surrounding structures, they are often used in urban settings for foundation repair, retrofitting existing buildings and for new construction projects. Helical piles are routinely installed as foundation elements in seismically active areas, such as New Zealand, Japan and the U.S.Anecdotal observations (e.g., from New Zealand, Japan and the U.S.) have shown that piles with a comparatively small cross-section and high anchoring capacity, such as helical piles, are beneficial for seismic resistance. This is presumably due to the pile’s slenderness, higher damping ratios, ductility and resistance to tipping uplift. In New Zealand, it was observed that helical pile foundations fared much better than driven and drilled concrete piles after the 2011 Christchurch earthquake. In a personal communication, Woods (2016) described that, out of the 300 structures in center city Christchurch that were supported by helical piles, fewer than 10 structures suffered significant structural damage. However, many structures supported by driven and drilled concrete piles were damaged to such an extent that they were condemned and subsequently demolished."

Jan 1, 2017

By Melinda J. Hummel, Zachary T. Smith, Nathaniel Witter, Nina F. Carney

The revitalization of Pittsburgh’s historic Strip District has led to the redevelopment of existing properties and the development of new properties. At one time, the Strip was home to wholesale market products. Now, the historical warehouse buildings are being converted to multi-use residential and commercial properties. One such property, 1600 Smallman Street, consisted of 1 to 6-story connected buildings that housed night clubs, retail shops, and office space. The lower story portion of the building, on the southwest side of the property, was torn down to make room for a new 5-story- parking garage with street level retail space. The remaining 6-story-building, on the northeast, was gutted to be renovated into high-end condominiums, keeping the exterior historical building facade.

By Luca Pingue, Regine Jagow-Klaff, Franco Muratore, Carlandrea Albonico, Damiano Frontini, Rudolf Wernecké

This paper describes an artificial ground freezing (AGF) application carried out to ensure both watertightness and structural support for the safe excavation of four cross passages of the Forrestfield Airport Link (FAL) project in Perth. The line will deliver 8.5 km extension of the existing urban rail network connecting the growing eastern suburbs of Perth with the existing suburban rail network. The proposed soil improvement technique is adopted as a smart alternative to jet grouting from the surface since the use of heavy equipment with long vertical mast was not allowed due to the line underpassing an airport in operation. In this paper, details of the challenges and lessons learned during both design and construction phases are given. Furthermore, it is described the geometry and the installation of freeze pipes in presence of a massive steel frame, ventilation system and slurry pipes of the tunnel boring machine (TBM) in operation. It is also illustrated the web monitoring system to allow key personnel to follow in real time the development of soil temperatures, tunnel convergences and ground surface deformations as well as changes in the interaction between international parties involved due to the COVID-19 pandemic.

May 1, 2022

By Nagarajan. D, Raja Rajan. K, Vijayakumar. T

Major bridges crossing mighty rivers must be constructed in flowing water. Constructing the sub-structure in water has been a challenging job for contractor. Special construction techniques with marine fleets to be adopted for waterfront construction. Enabling works like temporary piling platform and cofferdam used for pile and pile cap construction. Apart from this, enabling works like load out jetty to transport the materials from land to water; temporary walkway for access of workman to work location; temporary access bridge for construction vehicles movement; temporary liners for tower crane foundation; Concrete block to act as dead man anchor for barge movements were all required by the contractor for smooth functioning of site as per construction schedule. Investment in enabling works by contractor plays a significant role on profit margin of the project and of course with utmost safety. Design of enabling works for waterfront structures involves hydrological data like afflux, bathymetry survey, current force, scour depth and wave force to be taken cautiously for safe and economic design. Type of foundation and pile/well cap top level corresponding to water levels shall influence the construction scheme. Usage of geotechnical software like Wallap and Plaxis required for enabling work design to enhance the safety of the structure. Bathymetry and soil condition play a critical role in design and construction of enabling works. Water Discharge quantity in river along with water levels like low water level, high flood level, seasonal fluctuation of water levels has a great impact on design of enabling works. Establishing enabling works for waterfront construction near to an existing bridge is an additional challenge for the contractor. Along with design, constructing the enabling works in water requires special construction methodology and sequence of work. This paper shall provide insights on overview of design and construction of enabling works for waterfront construction.

Nov 1, 2022

By T Vijayakumar, Vipul Dobhada, Rajesh Patel, Swarnadip Dey, Naveen Babu D

The most challenging scope of any bridge project in marine or inter tidal zone is to construct sub structure like well Foundation, group pile, pile cap etc. Similarly, it also affects the marine environment/ecology to a great extent. Understanding the level of difficulties and aiding to provide an environment friendly solution, various options are analysed to overcome these and found mono pile to be the best alternative in this context. Generally, the foundation type of any bridge constructed in river, marine or intertidal zone in India is preferred for group piles. For the first time, monopile is being accepted as the foundation of bridge in India at Mumbai Coastal Road Project. The diameters of the monopiles used in this project are 2.5 m and 3.2 m. Hence, the challenges involved in monopile construction and experiences to overcome it are worth to share. Here, a brief discussion on environmental, geological issues and the needs of monopile as the foundation of bridge has been discussed. Furthermore, the monopile construction stages and confirmation of monopile capacity through different load tests have been elaborated.

Sep 1, 2022

By Venugopal B, M Kumaran, Thomas John, Vetriselvan A

The initial pile load tests are conducted to ensure the geotechnical capacity of the pile in a particular site condition. Normally kentledge method is adopted for the compression pile load tests. In this method the entire kentledge load is loaded above secondary beams which are supported by concrete blocks above the Natural Ground Level. So, it is important to ensure the SBC (for shear and settlement) of the natural ground. In one of our projects initially it was decided to go with kentledge system for initial compression load test on 56m long 1200mm diameter BCIS pile. The test load and total kentledge load were 2160t and 2700t, respectively. The soil strata mainly consisted of clay with low SPT N value and water table almost at ground level. It was suggested to replace top soil using Granular Sub-base (GSB) with good compaction in order to avoid excessive settlement of concrete blocks placed to support the kentledge weight. When the kentledge loading started, even before reaching 10% of total kentledge load, excessive settlement on the GSB layer was observed. This paper describes the problems faced during normal kentledge method and how it was overcome using the liner pile system for initial compression load tests in this particular site condition for higher test load.

Nov 1, 2022