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By Darrell L. Beddard

The test program information provided for some immediate changes on the upcoming contracts and in contract administration for the I-880 Replacement Project. Plan sheet modifications included changes to the pile data tables showing the actual demand load required for structural stability. The normal class of pile with a minimum load carrying capacity was removed. This provided for substantial pile length reduction at several locations since the structural loading was much less than the predetermined pile class ultimate capacity. New specifications were developed and standard specifications were modified to accommodate the newer foundations, installation procedures and pile acceptance criteria. Current Caltrans specifications require that the Contractor provide bearing capacity at the specified tip elevation. This requirement was removed and pile acceptance was determined by the Engineer. Acceptance criteria was established by the State and was based on. set-up trend over time. Static loading tests were reduced especially in areas where testing was performed on the indicator program. Testing procedures were modified and set-up periods were established before piles could be tested. For the contract near the San Francisco Oakland Bay Bridge (Unit E) the FHWA 1000 tons (8.9 MN) test beam configuration was completely changed. This provided added safety and allowed more tolerance in the pile placement for the testing operations. Indicator piles were added as companion piles to the static loading test piles. These piles were used for restrike events which included collecting dynamic data for calibrating the wave equation analysis with static load test results. Indicator piles also provided quick access for restrike events, where as, the static loading test pile needed modification to perform the restrike operation. Penetration rates were recorded for these operations. Wave equation Analysis Program (WEAP) was used in developing the acceptance criteria. The standard Engineering News Record (ENR) formula in the current Caltrans' Standard Specifications was removed for the contracts. Contractors were required to submit, prior to driving piles, a driveability study for their contract. These studies required discussion of their operations, method of installation, effects of soil set-up, set periods, hammer settings, bearing graphs, inputs to the WEAP program and complete a "Pile and Driving Equipment Data" form. Dynamic monitoring was detailed in the specifications on how the monitoring process was to occur. Set periods were established and restrike events were called out with the frequency of these events.

Jan 1, 1996

By Alain Pecker

The choice of a design concept for a bridge foundation is guided by various factors; several of these factors are indeed of technical origin, like the environmental conditions in a broad sense, but others non technical factors may also have a profound impact on the final design concept. The foundations solutions adopted for the Rion Antirion bridge are described and an attempt is made to pinpoint the major factors that have guided the final choices. The Rion Antirion bridge is exemplar in that respect: the foundation concept combines the simplicity of capacity design, the conceptual facility of construction and enhances the foundation safety. The design of these foundations was a very challenging task which required full cooperation and close interaction with all the parties involved: concessionaire, contractor, designers and design checker.

Jan 1, 2013

By KeerthiRaaj Subrmanian, Muthukkumaran Kasinathan

"A railway embankment is under construction between Nagapattinam to Thiruthuraipoondi covering 36.5 km. The sub-soil strata comprises of soft clay extending up to 10 m below existing ground level, which is subjected to stability and settlement problems. A trial stretch covering about 5 kilometer was improved using Prefabricated Vertical Drains (PVD) with surcharge was recommended to accelerate the consolidation settlement. The geotechnical characteristics of the subsoil are examined through laboratory tests on representative soil samples. Recent improvement in the finite element analysis has facilitated modeling of PVD in finite element software for computing the settlement magnitude and time rate of consolidation. In this study the theoretically predicted settlement magnitude and time rate of consolidation from Terzaghi.s vertical consolidation, Barron's radial consolidation are compared with the analyzed FEM results for both the cases with and without PVD improved embankment. The comparative analysis between FEM and predicted data hold good for stresses and the associated deformations. The excess pore water pressure was significantly lower and their dissipation was faster in case of embankment with vertical drains. Thus PLAXIS 2D tool shows fairly convincing results in comparison to the theoretical solutions.1. INTRODUCTIONFrom the earlier times civilization has been developed in a fashion either at the banks of river or near to the shore region, because of the easier availability of food and water. This over centuries made them as huge cities, consequently population rise made the increased necessity of highway, railways, port and even more ground for construction. As a stake researchers are pushed to make a low bearing ground into a massive carrier of skyscrapers, embankment, bridges etc. These low bearing ground suffers from total and differential settlement, slope instability. Hence, numerous ground improvement techniques were followed to eradicate these concerns which include preloading, piling, stone column, vertical drains and geosynthetic reinforcement. Among them Prefabricated vertical drain (PVD) are often used to accelerate consolidation of soft subsoil and has been the main soil improvement method used in improving the soft marine clay deposit (Chu et al.(2004); Chai (2001) and Arulrajah et al.(2003)). Literature review of embankment over soft clay deposit reveals that combination of PVD with preloading is widely considered as an economical and less time consuming ground improvement technique."

Jan 1, 2015

By Eric Brandner

Expansive soil formations can be found throughout the United States. When subjected to wetting, many of these formations have the potential to swell and exert large uplift forces which can significantly damage lightly-loaded structures. Designing an economical foundation that can resist uplift forces is critical to prevent damage to these structures. The current solutions to control uplift due to swelling soils, such as over-excavation and replacement of the expansive material, or drilled shafts, can be costly and problematic. Piles made from recycled polymer materials may provide a solution. Due to a lower coefficient of friction along the interface than piles made from traditional materials, solid recycled plastic piles can allow expansive soils to move nearly independently from the pile when wetted. This results in a much smaller magnitude of uplift force being transferred to the structure which minimizes the risk of significant structural damage. This paper presents the preliminary results of research conducted on the use of recycled plastic piles in an expansive shale environment. The preliminary phase of the project involved the installation of six 13 in. (330 mm) diameter recycled plastic piles at a test site on the South Dakota School of Mines and Technology campus. The piles varied in length from 15 ft. to 25 ft. (4.6m to 7.6 m). Two of the piles were subjected to a full-scale compression load test in order to determine ultimate capacity, while the additional four piles are being subjected to long-term monitoring of uplift movement. A cast-in-place concrete pile, with a diameter of 6 in. (152 mm) and length of 15 ft. (4.6 m), was also installed at the test site for monitoring. The preliminary results indicate that the use of solid recycled plastic piles is a viable alternative for support of lightly-loaded structures in expansive soil environments.

Jan 1, 2009

By Frank Rausche

The more widespread use of Augered Cast-in-Place (ACIP) Piles has generated increased demand for improved quality control measures. These deep foundation elements are often relatively long and slender and their structural quality depends on the experience of the installers, the adequacy of their drilling and pumping equipment, and of course, the properties of the soil. Since the concrete of ACIP piles is pumped under pressure into the borehole, the piles may achieve a very high unit shaft resistance if conditions are favorable and the piles are well constructed. Three types of methods can help assure that the piles are properly executed. During construction, monitoring the volume of concrete pumped and the pressure applied helps avoid structural defects. After installation, and once the concrete has hardened, the Pulse Echo Method allows for a check of the structural integrity of the shaft. Finally, a load test, performed some time after installation, yields a check of both bearing capacity and structural integrity of an individual pile. Because of their expense and associated construction delays, static load tests are normally done for only a few piles. However, at large construction sites, it may be necessary to perform many load tests either as a planned construction control activity or as a means of spot checking or verifying suspect piles. For smaller sites, however, static load testing may be prohibitively expensive. In such situations, dynamic load testing, originally developed for driven piles, has frequently been employed for drilled shafts and ACIP piles. In the latter case special consideration must be given to the ACIP pile slenderness and their often relatively low concrete design strength, which may not tolerate high dynamic loading stresses even though their unit resistance along the shaft is relatively high. Lately, the dynamic load test has become more feasible with the availability of loading systems that are custom tailored to this particular pile type. These systems produce a low velocity, low stress and high energy impact. Recent developments have also made the instrumentation process simpler: force measurements are now made on the ram rather than on the pile for increased reliability and simplicity. This presentation describes the requirements for successful dynamic load testing of auger cast piles and summarizes results from several projects where the new loading system and newly developed instrumentation was employed. A few cases are presented correlating static load test results with dynamic predictions, calculated by CAPWAP®.

Jan 1, 2001

By Ambarish Ghosh, Subhaprasad Chakraborty

"Construction of basement floors has become necessary to meet the requirement of parking in office and residential complexes and in hospitals for radiotherapy treatment. Important projects coming up in Kolkata are mostly in closer proximity of residential buildings, office buildings and historical monuments. Sheet piling is mostly used as temporary shoring system during construction. Deep excavation in urban environment creates great problem related to construction induced vibration due to driving of sheet piles for basement, pile driving etc. which raises the chances of damage of adjacent buildings and nearby structures. Vibratory sheet-pile driving is the most common method of sheet pile installation. The knowledge of induced vibration due to this phenomenon is still very deficient. This paper presents the analysis of measured vibration data collected from different sites of Kolkata with varying soil profile. Typical two case studies of sheet pile and pile driving has been presented and the vibration values are analysed. The responses of the vibration are reported in terms of peak particle velocities (PPV). To evaluate the effects of vibration due to pile driving two aspects have been considered: the effect of the energy entering the ground from the pile and the effect of the soil condition.INTRODUCTIONIn urban areas infrastructure development projects are mainly located adjacent to existing structures like residential buildings, offices and historical structures. The construction work of such project influences the surrounding environment as well as human perception (Wiss 1981). During the construction of basement for residential complexes and hospitals sheet piling is mostly used as temporary shoring system or as to support the earth mass. The vibration induced due to driving of piles and sheet piles have been presented herein. Deep excavation projects close to existing structures increase the concern of environmental impact. For this reason the vibration assessment and prediction has become a subject of great interest. It is important to develop a site specific model for predicting the ground vibration resulting from pile and sheet pile driving at the construction sites. The developed model gives the efficacy to guide the engineer to select the construction methodology ensuring the safety of the surrounding structure. The model developed here is site specific and the parameters that has been used are dependent on the soil condition and the energy source."

Jan 1, 2015

By David K. Crapps

The drilled shaft load tests at Port Orange were part of a demonstration project sponsored by the Federal Highway Administration (FHWA) and the Florida Department of Transportation (FDOT). Three load tests were conducted. Test 1 was a conventional test with the test shaft loaded from the top. Test 2 included an Osterberg load cell at the tip and a conventional load test from the top. Test 3 used an Osterberg load cell at the tip of a production drilled shaft. All three test shafts were socketed into limerock and were carried to failure. This paper describes the test program and presents a summary of the test results. Figure 1 presents some photographs of the load test setups and Figure 2 shows the location of the drilled shaft load tests. SITE CONDITIONS The Port Orange Bridge is located on US A1A over the Intercoastal Waterway in Port Orange, Florida (south of Daytona Beach). The new bridge will provide four lanes of traffic with a 65 foot vertical clearance for Intercoastal Waterway traffic. The channel and flanking piers will be supported by 54" drilled shafts socketed into the rock. The bridge is being constructed in two phases. The southern half will be completed first, the old bridge removed and then the northern half will be constructed. The first phase is scheduled to be opened to traffic in October 1989. Each of the four piers near the channel will be supported by 12 drilled shafts with 6 shafts per pier being constructed in each phase.

Jan 1, 1989

By Robert B. Bittner

The new gated dam on the Monongahela River at Braddock, Pennsylvania, was built for the US Army Corps of Engineers using an innovative ?In-the-Wet? technology. A key feature of this technology involves construction of the foundations through the water and later mating the completed structure or a shell of the structure to the pre-installed foundation. This paper presents a description of the structure, its foundation, construction sequence and design details required to successfully implement this technology.

Jan 1, 2013

By P. D. Arumairaj, B. Vani

"Micropiles are small diameter cast insitu reinforced grouted piles and it has been effectively used in many applications of ground improvement. It increases the load carrying capacity of soil and reduces the settlement. It is also used in strengthening existing foundations. In this study, the effect of Solid and Hollow micropiles on the load carrying capacity of footing resting on sand is studied. The effects of solid Micropiles are investigated by conducting experimental model studies. The parameters involved in this study include the position of pile, pile length and pile spacing. Load test was carried out on a model footing resting on sand with solid and hollow micropiles. Load test trail is repeated for footing on Micropiles with varying lengths of 10, 20, and 30 times the diameter and spacing equal to 5, 4, 3, 2 times the diameter. The load-settlement behavior of each case is compared. Optimum length and optimum spacing of both the solid micropile and hollow micropile are determined. It is also observed that the effect of micropiles in the peripheral of footing resists lateral displacement of soil underneath the footing. The micropile beyond significant depth becomes redundant.INTRODUCTIONA micropile is a small diameter (less than 300 mm) drilled and grouted pile that is typically reinforced - FHWA-NHI 2005 (Federal Highway Administration-National Highway Institution). It is constructed by drilling a borehole, placing a steel reinforcing element into the borehole and grouting it. Hollow micropiles are typically reinforced by solid central bar that occupies about onethird of the hole volume. The grout is placed by gravity, under pressure methods or by a combination of both (post grouting). Thus, micropiles can be considered as small drilled-shafts that are specially drilled and grouted.Historically, micropiles have been introduced in Italy as a foundation system mainly for retrofitting and underpinning of structures that had sustained damage during World War II and access for conventional piling equipment was not possible (Bruce, 1988). The second generation of micropiles is a pressure grouted piles with a central mono all thread bar (with diameter up to 89 mm). They are installed by using either an open or cased hole drilling method.A new generation of micropiles, termed Grout injection bore micropiles (IBOR), was developed in the 1980s. The IBOR, currently named hollow bar micropiles, utilizes a continuous all-threaded hollow steel bar as the drilling and grouting conduit, which allows drilling and grouting simultaneously without the need of a casing during drilling. A sacrificial (lost) bit with openings that allow for pressure grouting of the hole is threaded onto the end of the hollow bar and is left in place following drilling. A drilling fluid (air, water, or grout) is introduced through the hollow bar and allows the spoils to flush from the borehole opening. Upon reaching the required depth, neat cement grout is then injected under high pressure into the drilled hole to fill the annulus between the bar and the soil from the bottom to the top. Due to the grouting method employed, the shape of the hollow bar micropile is expected to have a bulb shape with an enlarged base."

Jan 1, 2015

By Annika Gram, Teddy Johansson, Lutfi Ay

Micropiles transfer tension or compression forces as well as cyclic loads into the ground via skin friction. The Self Drilling Micropiles (SDM) can be utilized for permanent applications. The hollow bar simultaneously acts, as drilling rod, injection tube and reinforcement for the micropile. The SDM system can be used in any type of soil, including unstable soils, without the need for temporary casing. Injecting a cement grout through the hollow steel tendon ensures that the borehole is filled from the bottom to the top. The system is fast, simple, and flexible. The installation minimises noise, vibration, and spoil. There are many potential applications, including foundations, underpinning, resisting uplift, dynamic/cyclic load applications and geothermal installations. The SDM technology were introduced to India first time in the Indian history and utilised in the 4G and 5G network projects. The SDM challenge the traditional cast-in-situ piles in the 4G project and raft foundations in the 5G project. Utilisations of the tensile and the compressive strength capacity of SDM with smart solutions results in noticeably big costs, 17-38 % depending on the soil conditions and time savings. The cost of the SDM solutions was about 40% less than the cast-in-situ piles and raft foundations in an ongoing 5G project. The SDM were used successfully in the liquefiable soil types as well.

Nov 1, 2022

By Patrick van der Schaaf

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

Jan 1, 1900

By Terence Ma, Seok hyeon Chai, Jeff Lam, Thamer Yacoub, Brigid Cami, Sina Javankhoshdel

The Limit Equilibrium (LE) analysis of pile-supported geotechnical structures normally assumes a constant shear force for the pile instead of considering the non-linear capacity of the pile which is related to the pile displacement. In this study, a 3D Limit Equilibrium analysis is carried out for a landslide model supported with piles by considering the constant and non-linear capacity of the pile which is computed using a separate Finite Element (FE) algorithm. The depth of the pile, soil layering, and the pile properties are used with an assumed maximum displacement to compute the geotechnical non-linear capacity of the pile. In this study, the results of the initial unreinforced 3D LE model was first compared to the 3D FE analysis results. Then, the pile pattern was applied to the failure region in the 3D LE model, and then the factor of safety was recomputed. The results of the constant shear piles were compared to the model with the non-linear piles.

Sep 8, 2021

By Federico Pagliacci

Continuous Flight Auger (CFA) technique represents an important technological advance in the construction of piles in soft soils. The possibility of excavation under the water table with no need for drilling fluids, along with high productivity, have resulted in this technique?s becoming widespread in many countries. However, CFA technology has limitations because of its difficulty in penetrating hard layers and cross strata with cobbles and boulders. In these situations, pile verticality may be an additional problem. The Cased Augered Pile (CAP) technique consists of penetrating the soil with an auger housed in a casing. Two independent rotary heads sliding along the rig mast operate the auger and the casing. By adjusting the height of the casing shoe and auger bit according to soil type, it is possible to drill piles in very severe conditions - in the presence of cobbles and boulders - and to socket the pile into the rock. The use of a steel casing enables improved pile verticality. Therefore, the CAP technique is also used to construct secant piles to be used as diaphragm walls. The limitations of this technology are the depth, usually no more than 27 m (88 feet), and the size of the rig that supports the drilling tool, no less than 70 t (77 short tons) in working conditions. This paper illustrates CAP technology, the drilling system, and the characteristics of concrete and steel reinforcement and offers a case study of the Palermo-Carini second railway line, which used CAP to construct the new 30 km (18.6 mi) railway line, 20 km (12.4 mi) of which passes through the very congested downtown area of Palermo. More than 300,000 m (186.4 mi) of piles have been drilled in dense calcarenite formations with unconfined compressive strength of 15-25 MPa (2,200-3,600 lb/inch2), soft clay, and silt formations.

By Federico Pagliacci

Continuous Flight Auger (CFA) technique represents an important technological advance in the construction of piles in soft soils. The possibility of excavation under the water table with no need for drilling fluids, along with high productivity, have resulted in this technique’s becoming widespread in many countries. However, CFA technology has limitations because of its difficulty in penetrating hard layers and cross strata with cobbles and boulders. In these situations, pile verticality may be an additional problem. The Cased Augered Pile (CAP) technique consists of penetrating the soil with an auger housed in a casing. Two independent rotary heads sliding along the rig mast operate the auger and the casing. By adjusting the height of the casing shoe and auger bit according to soil type, it is possible to drill piles in very severe conditions - in the presence of cobbles and boulders - and to socket the pile into the rock. The use of a steel casing enables improved pile verticality. Therefore, the CAP technique is also used to construct secant piles to be used as diaphragm walls. The limitations of this technology are the depth, usually no more than 27 m (88 feet), and the size of the rig that supports the drilling tool, no less than 70 t (77 short tons) in working conditions. This paper illustrates CAP technology, the drilling system, and the characteristics of concrete and steel reinforcement and offers a case study of the Palermo-Carini second railway line, which used CAP to construct the new 30 km (18.6 mi) railway line, 20 km (12.4 mi) of which passes through the very congested downtown area of Palermo. More than 300,000 m (186.4 mi) of piles have been drilled in dense calcarenite formations with unconfined compressive strength of 15-25 MPa (2,200-3,600 lb/inch2), soft clay,

Jan 1, 2017

By Dominic Ammon, Mark Rothbauer, Paul Landers P. E.

Across the Potomac River from the location of the DFI47 Annual Conference (October 2022), in Alexandria, VA, two large permanent anchored walls with a decorative shotcrete face were recently constructed for the North Hill project, a new multi-family and townhome development. The project was executed with a design-build approach for the Fairfax County Redevelopment and Housing Authority with review by the Fairfax County Geotechnical Review Board. The project was constructed in highly variable Potomac group sediments that include high plasticity clay/silt terrace deposits overlying coarser grained materials. The soils were over consolidated and exhibited potential for slickensides from relief of horizontal stresses from past erosion. The wall system was designed to include deep soldier piles and permanent long strand anchors considering past slope instability in the area. As the construction progressed, problematic soil conditions and water issues required modifications to drilling methods. The two permanent walls spanned 800 and 1,000 feet long with a maximum height reaching 40 feet.

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 Helene Kennedy, Josef Macsik, Yvonne Rogbeck, Gregory Makusa, Göran Holm

"Constructions activities in cities often imply large volumes of surplus material which could be treated by stabilization for re-use in new geotechnical constructions. Modification of dredged sediments by e.g. stabilization/solidification (s/s) is an example of sustainable handling option implying dredged contaminated sediments to become a potential resource for civil engineering constructions. The SMOCS project (Sustainable Management of Contaminated Sediments) within the Baltic Sea Region Programme 2007-2013 has developed a guideline based on a sustainability approach free to download at www.smocs.eu. The paper presents key issues in the guideline and highlights the importance of performing a field test as part of the design process. Two field tests with s/s-treated dredged sediments for new port areas are presented. Strength, permeability and leakage properties of s/s-treated contaminated sediments make beneficial use in geo-constructions possible. The influence of possible physical/chemical deterioration processes on the durability has been studied showing that freeze/thaw cycles might degrade the monolith of s/s-treated sediments. Consequently s/s-constructions shall be below freezing depth. Other deterioration processes such as salt and sulfate penetration were found of minor importance. Research is on-going to study the influence of and how to cope with freeze/thaw cycles on the long-term properties.BACKGROUNDConstructions activities in cities often imply large volumes of surplus material which could be treated by stabilization for re-use in new geotechnical constructions. The mechanical and environmental properties of the contaminated sediments could be modified through the stabilization/solidification method (s/s method) and provide a potential resource for civil engineering constructions. The SMOCS project (Sustainable Management of Contaminated Sediments) within the Baltic Sea Region Programme 2007-2013 has developed a guideline on management of contaminated sediments based on a sustainability approach. A field test on the application of the stabilization/solidification method for treatment of dredged soft contaminated sediments was implemented in the Port of Gävle, Sweden. The treated sediments were beneficially used as fill material in the new port area replacing ending natural resources."

Jan 1, 2015

By Christian Leble, Dr. -Ing. Jakob Vogelsang, Dr. -Ing. Oksana Solt, Dipl. -Ing. Joachim Meier, Dr. -Ing. Wolfgang Orth

In the course of closing the gap between the Brandenburg Gate and Alexanderplatz, the Museum Island station was built by Implenia Construction GmbH. The tunneling for the platform hall took place on a length of about 106 m (347 ft) under the protection of a major ground freezing measure and crossed the Spree canal as well as the listed castle bridge. The approximately 20,000 m³ (4.54 E+06 US gal dry) frozen mass lay mainly in the Berlin sands. In order to ensure safe tunnelling and to protect the adjacent buildings, the planners had defined requirements for the mean freezing temperature and thickness of the frozen mass. For a reliable conclusion on the dimensions of the frozen mass, we used innovative temperature sensors as well as the new, web-based 3D measurement visualization and the associated site-specific evaluation software. The largely automated evaluation enabled a quick and reproducible determination of the temperature distribution in the frozen soil and its thickness in the relevant cross-sectional areas. The measurements were validated by thermal calculations using the Finite-Element-Method. Thus, an objective and clear assessment basis was available to ensure rapid coordination between stakeholders. The evaluations provide new insights into the temperature influences from tunneling, the application of shotcrete and the concreting of the inner shell. The newly implemented active thawing system is also an interesting innovation.

May 1, 2022

By C. Vipulanandan

With the aging infrastructure, there is a need to maintain and extend the service life of steel structures in general and steel piles in particular. Steel piles support not only vertical loads but also dynamic horizontal loads in onshore and offshore applications. In order to select the appropriate methods to repair corroded steel piles used in onshore and offshore application, corrosion mechanisms were investigated with the rate of corrosion in various environments. The corrosion rate of steel in soil, water and soil-water interface varied from 2 to 500 µm/year. Based on literature review and analyses, the repair methods can be broadly characterized as protective coating, electro-chemical methods, wrapping and encasement and partial replacement of steel. Also, methods to evaluate the repair materials and the repair configuration have been documented.

By Shoji Higashi, Nobuhiro Honda, Takeo Asanuma, Tatsuo Nagatsu, Masaki Kitazume, Sachihiko Tokunaga, Shigeru Kubo, Hidenori Takahashi, Tsuneyasu Onishi, Yoshiyuki Morikawa

"Various kinds of civil engineering structures and facilities were seriously damaged in the earthquake in Tohoku and Kanto regions of Japan on 11 March 2011 due to the greatness of its magnitude. In contrast, many structures resisted the large seismic force having been reinforced by the CDM (Cement Deep Mixing) method, which is often used for increasing the bearing capacity of ground and improving seismic performance. This paper summarizes the field survey undertaken to investigate damage to structures and facilities reinforced by the CDM method. Several prefectures and metropolitan areas were selected for the survey, based on the occurrence of strong seismic motions. A total of 847 structures and facilities were studied, in the survey using a questionnaire, which mainly inquired about the appearance of structures and facilities. Of the respondents to the questionnaire, 789 replied that there were no seriously damaged structures. The paper presents the damaged and non-damaged sites of CDM-technique sites and non-CDM-techniques sites. It can be concluded from the field survey that the CDM Method demonstrates high efficacy and durability against a strong seismic motions.INTRODUCTIONDuring the afternoon of 11 March, 2011, a huge magnitude-9.0 Mw (Category 9.0 on the Richter scale) earthquake occurred about 25 kilometers below the Pacific Ocean’s surface off the coast of Tohoku. This massive earthquake, now called the 2011 Off the Pacific Coast of Tohoku Earthquake was the largest earthquake ever observed in Japan. The seismic intensity of this earthquake was measured 7, the maximum on the Japanese intensity scale, as observed 7 in northern Miyagi Prefecture. The earthquake caused severe damage over a wide area from Tohoku to Kanto, and triggered large tsunamis that struck the Pacific coast of Hokkaido, Tohoku, and Kanto. The number of missing and fatalities caused by this earthquake exceeded 18,000 persons, making this an unparalleled earthquake disaster with a cost-in-life toll not experienced by Japan in recent years. Because of the scale of its seismic motions, the earthquake damaged facilities and structures of many kinds. In the years prior to this earthquake, the CDM method was used extensively to increase the bearing capacity of the ground as an anti-seismic countermeasure and to prevent liquefaction. Immediately after the earthquake, the CDM Association visually surveyed the state of damage to about 800 facilities in the Tohoku and Kanto regions where a seismic intensity of 5 or higher was observed. This report summarizes the survey of damage to facilities and structures constructed applying the CDM method in order to confirm the durability and performance of the method against seismic motions."

Jan 1, 2015