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By Pete Howell, Patrick Granitzki, Alicia Plinio, Janitha Batagoda

The New York City Housing Authority (NYCHA) Red Hook Houses was subjected to damage during Superstorm Sandy. As a result, the NYCHA has an ongoing project known as Restoration Associated with Sandy Recovery Program to improve the resistance against future storms. The specific project included 28 residential buildings and several service buildings within the Red Hook Development. The subsurface conditions within the eastern portion of the site included existing fill material underlain by varying stratums of very loose, loose and medium dense silty sands followed by very soft to medium stiff clay or dense silty sands. The western portion of the site included existing fill material, very loose to medium dense silty sands and organic clayey silts underlain by very soft to medium stiff sandy silts. Based on the geotechnical report, a conventional driven steel pile system was specified containing two pile depths. As part of the project bidding, an alternative pile type was recommended and analyzed to provide quicker installation, reduce vibrations, reduce noise, and provide relatively large cost savings. Due to relatively high lateral loading, an innovative double steel casing drilled displacement piles was proposed as the alternative pile option. Field testing proved the piles capable of the required project capacities and the use of drilled displacement piles as the best alternative for the project and accepted by the NYCHA.

Oct 1, 2022

By Brian Isherwood, Tara Brown, Paul Kreycir, Jenny Earle

"The Shangri-La hotel and luxury condominium tower, recently opened on University Avenue in downtown Toronto, required eight levels of underground structure, four extending into the shale bedrock.Isherwood Geostructural Engineers was retained in 2007 by Anchor Shoring Limited to provide an alternative design-build solution to better address serious foundation risks. The site, bounded on three sides by City streets, abuts an existing 1957 14-storey building with five underground levels to the north. Sitting on the rock surface along the east perimeter under University Avenue runs the existing Toronto Transit Commission’s University Subway Line built by cut-and-cover in the 1950’s and which was believed to lie very near the property boundary at the southeast corner of the site.The bedrock under Toronto is known to contain very high locked-in horizontal stresses, much higher than can be resisted by shoring techniques, which result in inevitable wall movement when excavating deep into the rock. The strategy adopted to control the risk to the Subway, adjacent building, and major utilities is described in the paper, along with the comprehensive monitoring of movements, and their comparison to predictions.The ProjectThe 66-storey Shangri-La hotel and luxury condominium tower, recently constructed on University Avenue in downtown Toronto, houses 222 hotel rooms in floors 1-17; 287 residences on floors 18-49; and private estates including two 2-storey penthouses on floors 50-66. These comprise 873,000 square feet of development. Eight levels of underground basement are required to provide parking and other amenities, the lower four extending into the shale bedrock."

Jan 1, 2015

By William M. Dalrymple, William P. Owen, Benjamin S. Rivers

For the California Department of Transportation (Caltrans), geophysical applications have played an important role as part of a successful multidisciplinary approach to subsurface characterization for the design of high value structures. Since at least the 1950’s, geophysical methods have been deployed to guide the exploration drilling program and to maximize the return on drilling investment by increasing the amount of data obtained from test borings. Geophysical applications saw increased use beginning in the 1990’s, during the seismic retrofit of the state’s toll bridges and the replacement of the west span of the San Francisco-Oakland Bay Bridge. Over the intervening years, increases in computing power and increasingly sophisticated commercial off-the-shelf software applications have allowed Caltrans to leverage advancements and perform geophysical investigations of increasing complexity and scale. Ultimately, the goal of these efforts is to maximize return on investment, whereby increased investigation costs at the design phase are offset by reduced uncertainty regarding subsurface conditions, leading to reduced cost overruns related to change orders and unforeseen site conditions during construction. These objectives are consistent with the recent Every Day Counts (EDC) initiative to incorporate Advanced Geotechnical Methods in Exploration (A-GaME) into routine engineering practice. Caltrans is an implementation partner of the A-GaME initiative, and Caltrans’ practices represent a model toward the institutionalized geophysical site characterization practices for other transportation organizations. The authors provide a retrospective on 70 years of experience with geophysical applications for transportation infrastructure, with examples and observations on potential future direction of the industry.

By A. Daugiala, D. Coleman

In 2014 the New York State Department of Transportation (NYSDOT) awarded a Design-Build contract to the joint venture team consisting of Skanska which is the managing partner; Kiewit Corporation and Ecco III (SKE) and HNTB as the lead design firm. The design build team employed methods to provide schedule savings and commercial benefits to the owner NYSDOT. This paper presents the design approach and construction methods used to accelerate drilled shaft installation supporting the main span foundation for the cable stayed bridge. The drilled foundation contractor Underpinning and Foundation Skanska, a division of Skanska was responsible for assisting with design, budgeting and construction of the drilled shaft foundation construction. As part of the Request for Proposal (RFP) bid process, Alternate Technical Concepts (ATC) was encouraged by the NYSDOT. The JV team proposed an ATC which involved a scaled production shaft testing method to simulate the ultimate load level, commonly referred to as the “Chicago Method” was used in the rock socket employing the Osterberg Cell (O-Cell) testing procedures. To the authors knowledge this was the first NYSDOT project where this approach was utilized on a Demonstration/Production installation to validate construction procedures and load bearing capacities. Construction procedures, challenges and solutions are discussed in detail. Upon completion of successful drilled shaft construction, concrete integrity is verified using two methods – Cross Hole Sonic Logging (CSL) and Thermal Integrity Profiling (TIP). A comparison from the contractor’s perspective is provided. Finally the drilled shaft rock socket is tested to ultimate end bearing values while rock socket side shear stresses are not exceeding the service level loading. Lateral load test was also a RFP requirement; the test arrangement and performance are discussed in detail as well. The Kosciuszko Bridge location poised unique geotechnical challenges on many levels shifting towards an extreme boundary of parameters encountered in New York City Area for drilled shaft construction. The JV team and specialty drilled shaft contractor actively participating in the shaft design and construction practice coordination and working with NYSDOT yielded a successful foundation solution which provided cost and schedule savings to the project.

Jan 1, 2016

By Selvaganesh Selvaraju, Deepak Raj, Sandun N. Wimalasena

One of the world leading oil majors is carrying out a multi-billion-dollar expansion of its integrated manufacturing complex in Jurong Island, Singapore, the global oil trading and refining hub. Soil conditions at the site comprise 10-20m thick reclaimed sand, below which is 3-5m of soft marine clay underlain by stiff soils of the Jurong Formation. The conventional foundation solution would adopt driven precast concrete spun piles; however, precast spun piles have a high embodied carbon from the usage of steel and cement. In order to reduce the carbon footprint, an alternative solution comprising deep vibro techniques was developed. The EFFC-DFI carbon calculator was used to demonstrate the expected scope 1, 2 and 3 carbon emissions for both driven pile and vibro techniques. By using in-house, state-of-the-art fuel-efficient machines, alongside the innovative design concept and usage of natural materials such as sand and stones, actual CO2e emissions were reduced from a potential 21,000 tonnes, with the spun pile’s solution, to only 1,900 tonnes. The saved 20,100 tCO2e is equivalent to an average car driving 2,000x around the Earth’s equator. The paper discusses the application of soil improvement as a more sustainable, lower carbon alternative to conventional piled solutions.

May 1, 2022

By Ryan Weaver, Travis Coleman

The drilled shafts that support transmission lines and substations have been increasingly subject to testing to assess the integrity of placed concrete. Cross-hole Sonic Logging (CSL) has been used, but large diameter shafts with challenging site access are generally more favorable to Thermal Integrity Profiling (TIP) testing. TIP testing assesses the shafts based on measurements of the concrete temperature during curing. The TIP results provide assessment of integrity both within and outside the cage, along with information about the alignment of the cage and concrete cover. This data has allowed shafts with imperfect results to be subject to more detailed structural evaluations. However, it may not be well understood how to use this additional information by designers and engineers. The purpose of this paper is to present TIP results of transmission line foundations, both with and without issues with integrity, including cage shifting, minimal concrete cover, or soil inclusions. The intent is to provide general guidelines of the issues that merit additional investigation and those that should be recognized as inconsistencies inherent to underground construction. BACKGROUND This paper is intended to discuss some of the drilled shaft evaluations made when TIP testing is performed. The authors of this paper were recently involved with a transmission line project that was designed and constructed for a Confidential Utility Client located in the Midwest United States. The project was delivered as an Engineering, Procurement, and Construction (EPC) contract with the electrical line construction company as the prime contractor. The contractor then subcontracted several parts of the work which included engineering for transmission line and foundation design, foundation construction, and third-party testing intended to evaluate the concrete homogeneity and integrity of the place concrete in the deep foundations. The testing method selected was Thermal Integrity Profiling Method B, which uses thermal sensors embedded in the concrete. The TIP testing was administered by Mr. Travis Coleman with GRL Engineers, Inc. Mr. Ryan Weaver with Burns & McDonnell served as the owner’s engineer and technical consultant for the utility and was responsible for reviewing submitted TIP reports and providing recommendations to the utility on their acceptance, and if there were any issues that would warrant further discussion and analysis.

Jan 1, 2019

By José Carlos do Amaral, Marcelo Groszownik, Jorge Beim

"Initiated in 2008, the project of this 1800 km long Electrical Transmission Line is a job of extreme technical complexity, crossing regions of major forests and rivers. When ready, it will allow the large Brazilian states of Amazonas, Amapá and Pará to use the energy from hydroelectric plants, thus eliminating the need for the use of diesel fuel thermal plants, with their much larger environmental footprint. Due to its extraordinary characteristics, the Green Peace and the Discovery Channel constantly visited the job. The part between the Amazon and the Xingu rivers started in 2012, and encompassed about 100 transmission towers with up to 150 m height, through a region known as “Alagados”. This region exhibits a 1.5 m water level during the rainy season, and soaked ground the rest of the year. Navigation of regular vessels is impossible during the flood season, when a dense vegetation called “bulhado” fills the riverbed, and vehicle traffic is impossible during the dry season, due to the extremely low surface soil resistance. Great logistical and technical difficulties were encountered for driving and determining the capacity of the piles. New systems had to be developed for driving the piles, with the simultaneous use of 15 small piling rigs. The final penetration, total number of hammer blows during driving, plus Dynamic and Static Load Tests were used for determining the driving and acceptance criteria.The geographical challenge and initial conditionsThis paper describes the execution of foundations for a 500 kV Electrical Transmission Line in a region that becomes flooded during the rainy season and heavily muddy during the dry season. This is the monsoon climate, typical of the equatorial region of Brazil, where there is a rainy season lasting for about half the year, followed by a very dry season. The temperature varies very little throughout the year, due to the proximity to the equator. The locals call the rainy season “winter” and the dry season “summer”.The most important part of the so-called “Alagados” region is situated inside an Environmental Extractive Reserve (RESEX) called “Verde para Sempre” (Forever Green), created in 2003. This is one of the largest environmental reserves in Brazil. It is an area controlled by the Brazilian Environmental Control Department, the Chico Mendes Institute (ICMBio). The environment control parameters are very strict.No deep foundation had ever been executed before along the “Alagados” region. The main challenge faced on this job, however, was working in a place where self-propelling vessels or land vehicles and equipment cannot be used. During the rainy season there is a dense and intricate vegetation called “bulhado”, which prevents the movement of outboard motor boats with propellers going deeper than 50 cm. In the dry season, the heavy mud prevents the movement of foundation equipment, excavators, trucks and other machinery."

Jan 1, 2015

By Shoichi Tsukuni, Akihiko Uchida, Kazuo Konishi

"In order to investigate the effect of grid-form deep mixing walls as a countermeasure for liquefaction damage to roads and private houses in Urayasu, Japan, three dynamic centrifuge model tests were conducted. Urayasu is located in the Tokyo Bay area, and private houses in the city incurred severe damage due to liquefaction during the 2011 Tohoku earthquake. In grid-form deep mixing walls design, the distance between grid-form walls is critical to prevent liquefaction. This study clarifies the relationship between the settlement of private houses and the distance between grid-form walls under the conditions that exist in Urayasu.INTRODUCTIONMany private houses in Urayasu, Japan suffered severe damages due to liquefaction during the 2011 Tohoku earthquake (Photograph 1). Fig. 1 shows the location of Urayasu and the maximum acceleration of the observed seismic waves in the Tokyo Bay area. At Urayasu, the duration of the seismic waves (hereafter called the Urayasu Wave) was about 2 min. The maximum acceleration was 1.57 m/s2 (Fig. 2), which is relatively small. The damages occurred in the land reclamation areas that consist of loose sand with an SPT-N value less than 10.To prevent liquefaction in future, it is necessary to adopt suitable countermeasures in the areas where many private houses suffered severe damages. Grid-form deep mixing walls are one such countermeasure. Fig. 3 and Photograph 2 show grid-form deep mixing walls. Walls are constructed using the deep cement mixing method. Fig. 4 shows a plane view of planned grid-form deep mixing walls for roads and existing private houses in Urayasu."

Jan 1, 2015

By John C. Niedzielski

The existing US-70 Bridge over the Gila River at Bylas, Arizona is planned to be replaced due to its current poor condition. The replacement bridge is planned to be a 15-span, 1,904-foot (580 meter) long bridge, the third-longest bridge in the state highway system. Within the Gila River floodplain, granular alluvial soil is underlain by cohesive lacustrine soil; bedrock was expected due to nearby terrain but not encountered within the geotechnical exploration depth of 166.5 feet (51 meters) or less. Based on the anticipated loading conditions, design scour depths and the soil conditions, the full structural loads are carried by large diameter drilled shafts; therefore accurately determining the axial capacity of the proposed drilled shafts has important practical and safety implications. The conventional methods for axial capacity determination may be overly conservative to use for design in the site?s layered granular and hard clay soils. An Osterberg cell load test was performed to obtain detailed information on the load transfer from the drilled shaft in side friction and base resistance to allow optimization of the bridge foundation design. The full-scale field test played a significant role in the design of the project?s deep foundations, notably, by incorporating the specific subsoil properties and consequently, an exact prediction of the load-settlement behavior under loading. This paper provides the results of the geotechnical site investigations, drilled shaft load testing procedures, and shaft load distribution from the load test results. Comparisons were developed between predicted axial capacities of drilled shafts using several design methodologies and the axial capacity measured from static load testing. The load test results showed that underestimation of the axial capacity is evident using conventional methodologies. The exact prediction of the load-settlement behavior under loading combined with a site-specific design approach, resulted in a substantial reduction of foundation costs due to reduced drilled shaft dimensions.

By Matthias Pulsfort, Jiarui Du, Torsten Wichtmann, Achim v. Blumenthal, Diethard König, Rowena Verst

The influence of the interaction between support fluid and soil, e.g., filter cake formation, on the shear stress transfer in the soil-concrete interface of diaphragm walls and bored piles is still controversially discussed. Actual research on the soil-concrete interface using bentonite suspensions indicates that shear stress transfer is underestimated by existing standards. Investigations on the soil-concrete interface using polymer solutions are rare. Therefore, complementary field investigations and systematic laboratory studies were conducted to analyse the soil-concrete interface using both bentonite suspensions and polymer solutions. Thickness and composition of real-scale filter cakes were investigated on several slurry wall construction sites, where bentonite suspensions were used. Direct shear tests (60 mm x 60 mm) were executed for soilbentonite mixtures with varying amounts of bentonite and different granular fines representing a realistic bandwidth of in-situ filter cake compositions. Larger direct shear tests (300 mm x 300 mm) with preceding horizontal penetration, subsequent vertical tremie concrete placement, and filter cake consolidation were performed using both bentonite suspensions and polymer solutions. The results support the view that shear stress transfer in the soil-concrete interface can be described by a wall friction angle in a range of 25° to 30° for bentonite suspensions and between 35° and 40° for polymer solutions in non-cohesive soils.

May 1, 2022

By Mario Mauro, Jeff Taylor, Carlos Morales

"In 2007 the US Army Corps of Engineers classified the Herbert Hoover Dike in Florida as a Dam Safety Action Classification (DSAC) 1 dam, and started the implementation of one of the largest dam rehabilitation projects in the nation. The construction of the cutoff wall is a key feature of this rehabilitation work to upgrade the dike to current dam safety criteria. The cutoff wall installation is currently being completed on Reach 1, which extends from Port Mayaca to Belle Glade, under a Multiple Task Order Contract based on performance specifications and stringent verification criteria.For the construction of the cutoff wall TREVIICOS selected the self-hardening slurry method. Since the cutoff wall is installed through a layer of highly variable limestone with Unconfined Compressive Strength (UCS) up to 14,000 psi, the excavation requires the use of the hydromill equipment. This is the first successful application of the hydromill technology with self-hardening slurry in a large scale project in the US. This paper presents the details of the method utilized, the quality control procedures, and the experience gained over seven miles of cutoff wall installed.INTRODUCTIONProject LocationThe Herbert Hoover Dike (HHD) system, around Lake Okeechobee in South Florida, consists of a series of levees, culverts and locks and is approximately 143 miles long (Figure 1).Lake Okeechobee is the second largest freshwater lake in the lower 48 states of the United States. The lake is the primary drinking water source for numerous communities around the lake and to millions of people living along the lower east coast. The lake is also a vital source of irrigation for the agricultural industry in the South Florida region.Lake Okeechobee is 33 miles wide from north to south and 30 miles wide from east to west and has a surface area of 730 square miles. The average water depth of the lake is 9 ft."

Jan 1, 2017

By A. V. Rose

A redevelopment in the City of London has been constructed with a piled foundation system that is believed to be the first of its kind. The purpose of the research is to explore this novel foundation method, which involves the installation of closely spaced piles in a perimeter arrangement with a body of soil enclosed in the centre. Both centrifuge modelling and numerical modelling techniques are used.

Jan 1, 2011

By Brian J. Olson, Kevin Haiar

Originally constructed between 1939 and 1941 as part of Franklin D. Roosevelt’s New Deal programs, the Bonneville to Hood River 115 kV Transmission Line required an infrastructure upgrade to remain reliable and in-service. The line traverses the rugged landscape of the Columbia River Gorge on the Oregon- Washington border, featuring steep, talus slopes; uneven, rocky terrain; and a variety of environmental sensitivities. This paper details the design and construction of 27 micropile foundations for new, fire- hardening steel poles through a particularly challenging stretch of the alignment. The difficult access and environmental constraints at these sites designated them as helicopter-accessible and precluded the collection of detailed geotechnical information prior to construction. Micropiles provided a viable foundation alternative due to their portability and flexibility during construction. Detail will be provided on the extensive preliminary desktop study performed, as well as the process of developing engineering designs to successfully accommodate for variability and unknowns in complex geological conditions. With an increasing number of electric power projects traversing challenging terrain and facing similar obstacles, this project stands to provide valuable lessons learned to the industry.

Sep 8, 2021

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 Sina Z. Yekta, Zhangwei Ning, Pierre Frappin

This paper describes a DC (direct current) electrical resistivity method, which uses the contrasts in resistivity measurements to estimate the diameter of jet grouted columns as soon as they have been completed, with varying depth and water table, and without excavation. The measurement procedure is illustrated by several examples of application sites, including the Grand Paris tunneling works during the last 3 years where the method was systematically recommended in quality control for jet grouting works.

Sep 8, 2021

By Stephen Darmawan, Mahdi M. Disfani, Arul Arulrajah, Alireza Mohammadinia

Deep mixing using cementitious compounds is an in-situ method of ground improvement for improving the strength, compressibility of loose sand. Artificial light cementation can increase the stiffness of loose sands significantly and reduce the settlement of loose deposits. The increase in contact area between the particles with a thin layer of cementitious agent depends on the confinement and void ratio of the soil mass. Hence, the stiffening effect of cementation not only depends on the type and amount of cementing agent and inter-particular force chain of loose deposit but also depends on the stress level at the time of cementation. In addition, the cementation effect in loose deposits can be deteriorated at relatively low strain levels. Decementation softening can cause detrimental and irreversible impacts on the soil deposit. This study investigates the effect of initial confinement and subsequently the initial void ratio at the time of cementation on small strain behaviour and decementation softening of cemented loose sand under ko loading. The effect of inter-particular contact of sand particles based on the specific surface area and also soil density was also investigated by means of shear wave propagation. This study present insightful information on effect of primary consolidation stress levels, density of soil and cementation level on softening and collapse of loose deposits improved using deep soil mixing technique. Better understanding of soil-cement interaction by optimization of binder content for deep mixing activation can lead to increasing the level of confidence in using this technique in ground improvement applications.

Jan 1, 1900

By Patrick J. Hannigan, Seth Robertson, Rozbeh B. Moghaddam

The Top-Loaded Bi-Directional Test (―TLBT‖) and the conventional Bi-Directional Load Test (―BDLT‖) are full-scale static load test methods. In both methods, the test loads are applied bi-directionally to the deep foundation. The advantages of the conventional BDLT have been well established for cost efficient static load testing of deep foundations, particularly for large diameter, high-capacity drilled foundations. A conventional BDLT applies the bi-directional test loads using an embedded jack and bearing plates. The TLBT method also applies the bi-directional test load to embedded bearing plates but does so using reusable high-strength threaded bars attached to an above-grade hydraulic jack and load transfer assembly. The new TLBT method is well suited for load testing shafts of a moderate diameter, length, and nominal resistance or ultimate load. TLBT advantages include economic considerations resulting from the method’s reusable load application components and constructability considerations as it readily accommodates a center concrete tremie pipe or pump line location. This paper presents comparison results from full-scale load tests performed using both bi-directional load testing methods. Adjacent 3-foot diameter by 30-foot long BDLT and TLBT shafts were tested. Details regarding subsurface conditions and test shaft construction are included for the comparison of the TLBT and BDLT results. Corresponding test data and analyses for both test shafts are presented and discussed in detail. The BDLT shaft had a maximum uni-directional load of 240 kips at upper and lower bearing plate displacements of 0.5 and -3.8 inches, respectively. The TLBT had a maximum uni-directional load of 300 kips at upper and lower bearing plate displacements of 1.0 and -5.9 inches, respectively. These results as well as the load-transfer behavior and equivalent top loading curve results from the adjacent BDLT and TLBT drilled shafts are discussed. The paper also discusses the strain gage instrumentation on the TLBT load application bars and on the embedded bearing plates.

Oct 1, 2022

By Carl-Oscar Nilsson, Åke B. Nilsson

"The embankment dam at Storfinnforsen is 23 m high and was completed in 1954. The dam has an impervious zone with timber sheet piles and a support fill of glacial till. The pore water pressure in the downstream shoulder has during recent years increased due to deterioration in the sealing function of the timber sheet piling. There is a concern that the high pore water pressure in the glacial till will cause internal erosion initiating at a thin coarse transition layer between the glacial till and the rock fill along the downstream toe. As a remedial action in order to improvement of the leakage resistance a supporting berm of coarse rockfill against the downstream slope of the dam was constructed in year 2013. In addition a new impervious seal in the centre of the dam e.g. a diaphragm wall was considered. However, after further studies and a trial stretch of 40 drains each 20 m long and diameter 0.3 m an alternative with vertical drilled drains in the downstream support was selected. A contract has now started up to drill in a similar way to treat the full length of the dam with drains. The work is in the planning to be completed in 2016.Dam ConstructionStorfinnforsen Embankment Dam was put into operation in 1954. The dam is 330 m long and maximum height is approximately 23 m. The dam is constructed with a central core zone and supporting zones of earth and rockfill on the upstream and downstream sides giving an almost symmetrical cross-section about the dam axis, see Fig. 1. The upstream slope is 2H:1V down to el. 270 and 2.5H:1V below. On the downstream side the slope is 1.75H:1V down to +269 and 2H:1V below. The core zone consists of a timber sheet pile wall with a Zone 5 of glacial till, approximately 2 m wide, adjacent to the wall on the upstream side."

Jan 1, 2016

By Brian M. Fraley

"Portions of the Catholic Total Abstinence Fountain in Fairmount Park in Philadelphia, Pa., were in “imminent danger,” according to a restoration services request for proposals (RFP) issued by the City of Philadelphia in August 2014. Open voids in the subsurface beneath the foundation were causing ongoing settlement of the fountain.The fountain was unveiled in 1876 as an ornamental drinking fountain for the Centennial International Exhibition, which celebrated the signing of the Declaration of Independence. Its creation was commissioned by the Catholic Total Abstinence Union of America, an Irish temperance organization that advocated for total abstinence from alcohol. Ironically, the fountain ran dry decades ago.The now-defunct fountain features a 100 ft (30.5 m) wide granite base with three steps in the shape of a Maltese cross. The centerpiece — enclosed by a 40 ft (12.2 m) diameter basin — is a 15 ft (4.6 m) tall statue of Moses perched atop an iglooshaped marble mound. Four subsidiary statues rise from granite pedestals at the tips of each arm of the cross, including Archbishop John Carroll, Charles Carroll of Carrollton, Father Theobald Mathew and Commodore John Barry.Natural and Man-Made DamageThe City of Philadelphia’s RFP called attention to three “high priority structural areas.” It was noted that Moses, Father Mathew and the steps surrounding the fountain had been documented as public hazards. The long-term effects of water infiltration had set in, eroding mortar joints and causing some stones to jut out. Furthermore, the stone base supporting the 16 ton (14.5 tonne) statue of Moses was in danger of collapsing. The statue of Father Mathew had been struck by lightning in 1910 and was repaired with an iron and metal pin anchor system, which had succumbed to corrosion. The city considered the statue of Father Mathew as the most threatened of the statues. Mike Miluski, P.E., vice president of Compaction Grouting Services (CGS), recalled “the fountain was in pretty bad shape” as he walked onto the site in August 2016 and immediately recognized the challenges ahead."

Jan 1, 2017

By H. Hayashi, M. Yamaki, H. Hashimoto, T. Yamanashi

"In an experiment on a trial embankment, the deformation mode of the improved ground at the toe of the embankment was compared with the deformation mode of the unimproved ground. This comparison showed that the behavior exhibited by the improved ground was the same as that exhibited by the unimproved ground, despite the low improvement rate (ap = 10%) of the ground improvement. Thus, the improved ground and the unimproved ground were found to be functioning as composite ground. Further, the strain that developed in the geo-textile used for the crushed-stone mat was considerably less than the strain specified by the design strength. As a result, it was found that a crushed-stone mat can serve as a mattress.OVERVIEW OF THE TEST CONSTRUCTIONLow Improvement-Rate Soil in Combination with Crushed-Stone MatIn Hokkaido, approximately 2,000 km2 of the land is peat land, an area almost as large as Tokyo. Such land accounts for 6% of Hokkaido’s plains and 2.4% of its total land area. The peat layer is normally 3 to 5 m thick and underlain by a layer of soft, cohesive soil whose thickness may exceed 20 m. In such a ground, consolidation using cement may generate differential settlement between improved soil as a result of embankment construction or lateral deformation caused by the slipping of unimproved ground. Therefore, the improvement ratio (ap) is designed to be at least 50% by the Manual for Construction on Soft Peaty Ground (CERI, 2011 [1]). Consolidation of ground with a low improvement ratio in combination with crushed stone-mat installation is a measure for soft ground (Figure 1). In this method, soil with a lower Improvement ratio than that of conventional improved soil (e.g., ap=10%) is placed beneath the entire embankment and a “crush stone mat”, a layer of crushed stone (t=0.5 m) enclosed by geo-textile, is then placed between the embankment and the soil."

Jan 1, 2015