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By Leonhard Weixler, Jean Wehbe, Gordian Ulrich, Franz-Werner Gerressen

"As alternative energy industries pick up speed internationally, and as government regulation and restriction limit the use of impact hammers due to environmental limitation from construction induced noise during pile driving operations, unconventional solutions for more complex offshore foundation installations have become a necessity. Manufacturers and equipment suppliers race to develop alternative techniques to accommodate for offshore foundation construction in various soil conditions and at greater water depth. The FLYDRILL, and the Seabed-Drill BSD are two innovative systems for the installation of offshore monopiles with reduced environmental impact.INTRODUCTIONThe FLYDRILL and the Seabed-Drill were born from techniques in the design and construction experiences gained from land based foundation drilling systems over the past 25 years. As the alternative energy industry ventures into uncharted territory of deeper water for offshore wind farms, fast current regions for tidal energy, and increasingly challenging soil conditions and project complexity, the advancement and development of new innovative equipment system and drilling techniques have become a necessity.The systems described herein show the development of the so called “FLY-Drill” system, and the all new “Seabed-Drilling” equipment applied at the first ever made job using a seabed drilling rig.FLY DRILLThe FLY DRILL method is a completely new concept for bored piling. The drilling unit with rotary head, Kelly bar, and drilling tool is suspended by the hoist rope of the base carrier crane. The hydraulic power for the drill unit is provided from the base crane.The drill head is fixed on the casing with a hydraulically operated clamping system during the drilling operation. When emptying the drilling tool, the clamp cylinders are opened and the complete unit is swung sideways."

Jan 1, 2017

By Stephan Fisch, Franz-Werner Gerressen

"The use of cut-off-walls (COW) for the open pit coal mines has been used for decades. They have been used to reduce the negative hydraulic impact to the surrounding area caused by the open pit mining. The pile-guided trench cutting system is a worldwide unique technique, originally developed by the engineers of the mining companies themselves. It guarantees a continuous, joint free, COW during a continuous installation process. At this specific site in Welzow, this technique has been pushed to new limits in order to address the local lake region. Depth capability has been designed to about 430 ft (130m), proven are already depth of about 360 ft (110m) at a constant trench width of 39 inch (1000 mm). This project is approximately. 6.8 miles (11 km) long of COW, scheduled to be completed in 12 years period. About 2.05 miles (3.3km) have been installed, which is equivalent of about 3.5 Million ft² (330,000 m²). The system flushes special clay which forms a filter crust at the inner surface of the trench. Only natural clay resources used, in order to achieve the cut-off effect (colmation effect). The paper explains the installation process of the cut-off-wall as well as the equipment systems developed specifically for this project. After a successful start of the first phase of the project, the next step in the advancement of the equipment is already underway to enable the installation of greater depth to approximately 490 ft (150 m +) and beyond. The next generation equipment system is scheduled to start operation around 2018 INTRODUCTIONThis Serbian saying “Bóh je stworil Lužicu a cert je zaryl brunicu – God created Lusatia and the devil buried brown coal underneath it.” captures local communities’ ambivalence towards lignite.Lusatia is an almost entirely flat stretch of land between the Elbe and Neiße rivers dominated by glacial sands. On the surface, the heathland and woodland is hardly noteworthy. However, three large lignite mining regions, two in Brandenburg and one in Saxony, in the east part of Germany, divert the attention to underground level, down to depths of up to 120 meters. Here, seams crisscross the earth like ribbons. They were formed in the Tertiary around 17 million years ago.The mining of the lignite started almost 200 years ago. To enable open pit mining, a suitable dewatering system was required. At first, wells and drainage system were used. With the increasing demand to go deeper to enable full use of the existing resources with greater mining depth, a decision taken back in the 60th of the last century, the amount of water which had to be pumped increased dramatically. In peak times, approx. 1.57 Billion cubic yards per year (1.2 Billion m³/year) had to be pumped. This led to a lowering of the groundwater level for up to 230 ft (70 m), impacting the regional lake landscape. In order to reduce the influence on the water balance, and bring the water level back to pre1970th, a first development took place to implement the use of specific COW system to depth of about 147 ft (45m)."

Jan 1, 2017

By P. V. Chandramohan

"The paper deals with the arrangement of structural members for a retaining structure used as a berth in the port of Krishnapatnam. The height of retention is 24.3m. A T-shaped diaphragm wall acts as the retaining surface. A relieving platform has been provided at the top to ease lateral earth pressure on the wall. The diaphragm wall is tied back to a combination of vertical and raker pile. Later, this arrangement was altered to replace the relieving platform with just lowering of ground level below the berth. The tie back was changed to a classical A-frame anchorage. At certain reaches, installation of piles pointing towards the rear was obstructed by a conveyor structure. The anchorage was then changed to include a vertical pile and a pile that points towards the front of the berth. Change in position of inclined pile alters the force in the pile from compression to tension.GeneralPort is a major link in the multimodal transport chain. Berth is the heart of the Port infrastructure. It is here the ocean freight changes to land transport. The change-over, warrants special type of heavy duty handling equipment. The equipment and the process necessitate deep seated foundations. On one side of the berth, deep drafted ships would be berthed. But adjacent to this heavy duty cranes would be operating at the deck level. Berths are of various types. Some are founded on piles and may project into water. Some operators prefer a retaining structure. At the port of Krishnapatnam, a retaining structure was preferred. Dredged level at the berth was to be -20. Deck of the berth was at +4.3. This meant that the height of retention of soil was 24.3m. Ports are generally located near the coast. Subsoil in the port area generally consists of cohesive material of low shearing strength. The berth has to cater to imposed vertical and horizontal loads.Structural functionFor bulk cargo and containers, berth has to support the two crane tracks. These tracks will carry heavy wheel loads of the crane. Besides, the space between the tracks would be used for stacking of cargo or hatch covers. In short, the deck will be subjected to heavy surcharge. This vertical load will manifest as additional lateral force on the retaining wall. Since the height of soil to be retained is high, it is a practice to relieve the lateral earth pressure due to the heavy surcharge of the wall. This is done by providing a relieving platform. The surcharge of superimposed load on the deck and the self-weight of the soil up to a few metres below would be relieved by a suitable platform. This vertical load would be transferred directly to deeper levels through piles. Mooring pull is a horizontal force exerted by the vessel on the bollards towards water side. Berthing force is exerted by the vessel during berthing, through fenders and acts towards land side.Diaphragm walls are usually employed as the retaining face. If the height of retention is less, these walls can cantilever out but in the case of large retention, they have to be tied back. The ties are to be anchored on to suitable arrangements like a dead-man or an A-frame. Berthing structure in the early stages at Krishnapatnam port is shown in fig 1."

Jan 1, 2015

By Emad Farouz

This paper presents a case history of a successful construction-phase pile load test program that optimized the pile design in challenging ground conditions at the Great Neck Wastewater Treatment Plant in the Town of North Hempstead in Nassau County, New York. The improvements and expansion of the wastewater treatment plant included the construction of several new structures to comply with new stringent nitrogen discharge requirements and new design flow. The challenging ground conditions included up to 20-ft thick organic deposits with weight of hammer blow counts and up to 14 percent organic content and tidal ground water that was near the ground surface. The foundation design evaluated various deep foundation alternatives and selected driven closed-ended pipe piles then filled with concrete as the most suitable foundation. The selection process included considerations of cost, risk, vibrations, noise, and schedule. The contract documents utilized an innovative approach of performing an optimization load test program that was implemented during construction to optimize pile lengths and reduce potential vibration and construction schedule. This paper discusses the details of the successful load test program including static testing, dynamic testing, and the innovative contracting approach utilized to implement the construction phase load test program. It also discusses the successful development and implementation of driving criteria for production piles and construction challenges. The successful load test program resulted in savings of several hundred thousand dollars, optimized schedule, and lower environmental impacts.

By Benjamin B. Buensuceso III

Crosshole sonic logging (CSL) is a popular quality assurance and quality control method used to examine the concrete quality of cast-in place deep foundations, though the evaluation of the results is subject to certain limitations. One such limitation explored in this paper is the occurrence of false positives, where signal anomalies indicated by CSL test results are not necessarily indicative of imperfections in the foundation that could affect its performance. A case study of false positives evaluated in CSL records in a major infrastructure project in Metro Manila is presented in this paper. A detailed desktop evaluation and results from complementary high-strain dynamic load testing and low-strain pile integrity testing were used to evaluate the significance of the suspected false positive signal anomalies from the CSL test results. Recommendations for the proper interpretation and evaluation of CSL test results in Philippine practice, given the method’s limitations and examples presented, are also shared.

Sep 8, 2021

By Venugopal Bonani, Kumaran M., Thomas John

Liquid storage tanks are usually located in nearshore or coastal regions with soil profiles containing thick layers of compressible soils. These storage tanks are usually of large diameter up to 90m and carry high loads, and the tanks are supported by heavy deep foundations such as piles. These structures are subjected to huge lateral loads due to wind and earthquake, and any damage to storage tanks with highly inflammable liquids leads to disastrous condition. So, it is important that the top layer of soil (up to the fixity depth) should be strong enough to provide the required lateral load capacity to the pile. In a project for constructing LNG terminal in Odisha containing 2nos of 89m diameter LNG storage tanks supported with pile foundation located near to coastal region, for improving the lateral capacity of existing soil, the top 3m was replaced with compacted engineered fill (GSB). The site was a filled-up area with dredged soil from seabed, the top 5m-10m were soft to medium stiff clay with SPT N less than 10. The lateral design load on pile was 534kN under free head condition. Actual lateral capacity for the strata was around 200kN under free head condition which was less than required capacity as per structural requirements. Therefore, for improving the lateral capacity of pile the top 3m soil is replaced with well compacted engineered fill (GSB) in layers of 150mm and the capacity is proved by conducting initial and routine lateral load tests. This paper describes the properties of the engineered fill used and how the lateral load capacity of pile was improved to meet the design requirement.

Sep 1, 2022

By A. Flora, E. Bilotta, F. Foria, V. Nappa

"All the typical applications of deep mixing rely on the good mechanical properties of the improved columns to strengthen or stiffen the ground for a number of geotechnical applications.This paper focuses on a completely different kind of deep mixing, carried out in order to obtain columns much softer than the surrounding soil. This kind of deep mixing, named Soft Deep Mixing (SDM), is introduced as an original means to tackle seismic risk, and can be convenient when the existing structure to be protected has a historic relevance that cannot be altered with structural modifications. The idea is that properly assembled layers made of partially overlapped SDM columns, with dynamic impedance much smaller than that of the surrounding soil, will filter and reflect most of the seismic energy.The paper presents the results of some 2D parametric numerical analyses aimed to investigate the seismic performance of this innovative approach. Simplified dynamic inputs (Ricker wavelets, having only one largely predominant frequency) were adopted to better understand the effect of signal frequency. The analyses show that the effectiveness of the soft grouted isolating barrier depends on soil and SDM geometrical, physical and mechanical properties, as well as on the frequency content of the seismic input.INTRODUCTIONPassive structural systems installed at the foundation level of existing buildings are a common solution to protect them against earthquakes. However, installation procedures are expensive and not always feasible, as for instance in the case of valuable buildings. As an alternative, ground improvement techniques can be used to modify ground properties, in order to mitigate the intensity of shaking at ground level. The propagation of shear waves in the ground can be modified by introducing a layer of artificially modified material, having a dynamic impedance (defined as n =p VS, where p is the material density and VS the velocity of shear waves) very different from that of the natural soil. Both very high or very low values of the dynamic impedance of the grouted soil (nt) can be effective in reducing the overall transmitted energy, with the difference that – for a given reduction of the transmitted energy - stiff grouted layers tend to filter the low frequency components of the amplitude spectrum without modifying in a significant way the high frequency components, while soft grouted layers have the opposite effect. Then, ideally the choice of the best grouting technique should be made considering the effects of the different frequency components on the building to be protected. These effects are detrimental for the structure when they are close to its natural frequency: high frequency components result into large structural loads on massive squat structures (high natural frequency), and low frequency components may be critical for tall and flexible structures (low natural frequency). Therefore, the typical procedure of stiffening the uppermost soil layers regardless of the kind of building to be protected is not necessarily beneficial, and for the case of squat structures soft grouting should be preferred. However, this procedure has not been taken into account yet in the engineering practice, and may pose static problems at ground level (i.e. excessive static settlements)."

Jan 1, 2015

By Lu Yitan, Frances Badelow, Manish Tiwari

"Large ‘design and construct’ projects often present significant geotechnical risks. However, these also present significant opportunities for value engineering in design. These opportunities can be realised through systematic site investigation and close collaboration with the Contractor to dovetail the design solutions to suit construction methods. This paper presents a case study of a large infrastructure project in Singapore which involved design optimization of an earth retention system for a deep excavation in a constrained urban environment. The project also required installation of over one thousand bored piles in highly variable ground conditions - identified as a key risk. Systematic site investigation was undertaken to develop a reliable ground model. A detailed value engineering exercise identified opportunities for design optimization by changing the retention systems and construction sequence in some segments. An innovative low cost ground improvement method was used in some areas to reduce the forces on the retention system. An extensive instrumentation and monitoring plan was implemented for verification of design and to mitigate the remaining risks. This paper includes the lessons learnt on this challenging project, which are relevant to a wide range of construction projects.INTRODUCTIONSingapore has been rapidly expanding its underground Mass Rapid Transit (MRT) network over the past two decades. The Thomson-East Coast Line (TEL) forms part of this expansion and is 43 km long and fully underground comprising 31 stations. This paper describes the value engineering and design optimizations undertaken during detailed design of the earth retaining and support structures (ERSS) for one of the underground stations along TEL. The station, currently under construction, is up to 24m deep and 350m long. The edge of the station excavation is less than 10m away from the existing MRTviaduct. The proposed station is surrounded by high-rise residential and commercial structures, somewithin 2m of the excavation. Land Transport Authority (LTA) of Singapore imposes stringent technical and contractual requirements on MRT construction works to ensure high quality and safety standards. These include minimum requirements for embedment of retaining walls, groundwater control, additional site investigation, instrumentation and monitoring, and compliance to LTA’s Civil Design Criteria (CDC). Any deviations from the minimum requirements can only be approved by LTA after detailed calculations, analysis and field testing are completed and additional monitoring and control measures are proposed."

Jan 1, 1900

By Michael Arnold, Jignyash Manyam, Yoav Rappaport

The USACE required construction of over 13 miles of cutoff wall at an average depth of 65 feet for the Herbert Hoover Dike (HHD). To meet project requirements, to provide quality control and make sound operational decisions, automated data capture, retention and visualization is crucial. Accurate and complete data management allows the authors to deliver critical business insights and to improve operational efficiencies. The author’s understood the necessity of capturing all their data, and efficiently processing and displaying it for multiple stake holders, for both internal and external purposes. The authors realized early in the project life cycle that data ownership and management is one of the fundamental features of the construction process. The authors developed their own software and use two in house applications; WEB-BGM online portal and, b-project which store rig production information combined with field quality control. b-project is used to create and deliver the Enterprise Database (EDB) to the USACE. Another biproduct of capturing the production data is the generation of the Geographic Information Systems (GIS) and also business analytics visual interactive display, developed through Microsoft Power BI. The paper focuses on the business process workflow and various technologies employed and lessons learned from the field operator perspective to achieve higher returns on business software operations.

Oct 1, 2022

By Jim Bruce

No answer required. From the drilling equipment suppliers, but the specifications must be tailored to be project-specific. Yes, the sonic technique is very interesting as we said, and it is not so much as an issue of the magnitude of power, it's about the efficient use of the power. The efficiency of the machine is not necessarily related to size so it is best to talk to the two contractors that supply the service about that. I think it can be scaled down but it is quite a big head, so therefore there are practical limitations on the size of the door it can walk through and also the size of the casings and rods that it can use. You might defeat the economic advantages if you were to use too short casing lengths. Boart Longyear have a low head room machine that can work within an 8 foot verical clearance.

Feb 10, 2003

By Emre Turk, Suat Gullu, Candan Gokceoglu, Ahmet Sirri, Asli Can

In this study, the ground improvement application applied under the live railway bridge's approach embankments in Sivas, Türkiye was investigated as a case study. The soil profile is mainly composed of orangish conglomerate, clay, silty sandy clay, and under claystone, and mudstone units in the study area. As a soil improvement method, the Deep Soil Mixing (DSM) technique based on the principle of simultaneous mixing the ground while injecting with the water-cement mix, was selected. The application of DSM columns is designed to be 45 degrees horizontal, in order to reach the deepest point of the soft clay units for better improvement against settlement. The core samples were taken from the DSM columns and the compressive strength tests were performed in the laboratory. The results were higher than the minimum designed values. It means that inclined DSM columns were applied successfully, and the excessive settlement problem was solved.

Oct 1, 2022

"Every year during the Transportation Research Board (TRB) Annual Meeting in Washington D.C., the Federal Highway Administration (FHWA) National Geotechnical Team (NGT) takes time to talk about what we are doing in research, training development and policy support. At times, I have jokingly referred to it as the State of the Program Address, but we do see it as an important opportunity to update our transportation partners on priorities and needs for the program.This update is really a snapshot of the program during the previous year, with a look at projects that are currently active. Activities undertaken by the NGT are funded from multiyear roadmaps maintained by the FHWA program and research offices, and reflect trends and opportunities affecting and influencing transportation geotechnics now and in the future. The roadmaps identify activities in research, development, guidance, technology transfer and training that will be accomplished by the NGT through and beyond FY 2020 in eight broadly-defined focus areas: • Extreme events, geohazards and sustainable geotechnics• Performance management• Reliability-based design and construction• Advanced geotechnical modeling• Alternative delivery methods• Design and construction optimization• Site characterization• Quality assuranceThe process to identify focus areas and to develop activities that will be addressed by the NGT is guided and informed through input from the FHWA NGT members, and considers feedback and input from State Departments of Transportation (DOTs), FHWA Division offices, industry and academia. This process is revisited annually to review not only the activities that are currently funded, or will be funded, but also to review the relevance of the focus areas with respect to the future needs of the FHWA, State DOTs and the transportation community.In 2016, the NGT was successful in delivering several products that will advance the state of the practice and that better support policy. Products developed included research reports, design and construction guidance, and training courses. In 2017, the research and program offices will continue to work on projects that fit within our prioritized plan and that positively impact the geotechnical community as a whole. A listing of recently completed and currently active projects is provided below."

Jan 1, 2017

By Andrew Cushing

This paper presents the design and construction of the foundation for a major high-rise real estate development on the west side of Manhattan. Arup was retained by Underpinning and Foundation Skanska to design a secant pile wall as excavation support for a proposed two-level basement of a new 23-story residential building located at 100 11th Avenue and West 19th Street. The secant pile wall will also act as the permanent basement retaining wall for the new building. The site is bounded on two sides by existing structures and is underlain by a thick deposit of very soft organic silt and clay. Therefore, the potential for ground movements and their impact on an adjacent structure bearing on shallow footings were of the utmost concern. This paper addresses the design and construction considerations associated with this secant wall, as well as installation details. Measured wall movements are also used to assess the validity of the pre-construction soil strength and stiffness design parameters.

Jan 1, 2008

By Louay Owaidat

The United States Army Corps of Engineers (USACE) Sacramento District awarded a $64 million construction contract in February 2020 to the Maloney Odin Joint Venture for 3 mi (4.8 km) of levee improvements along the Sacramento River East Levee (SREL). This project kicked off approximately $1.5 billion of work to upgrade levees along the American and Sacramento Rivers and widen the Sacramento Weir and Bypass. The project received the 2021 ASCE Region 9 Project of the Year Award. Contract 1 improved levees along five segments of the river, the longest segment being a 2 mi (3.2 km) reach from Garcia Bend Park to the Freeport Intake Facility in the Pocket neighborhood of Sacramento.

Oct 1, 2022

By Osvaldo Valdez, Matteo Bertoni, Aem Ragy

The East St. Louis Deep Cutoff Wall project is located in the area of East St. Louis, Illinois, across the Mississippi River from the city of St. Louis, Missouri, along the left descending bank of the river. The project is a fundamental part of the U.S. Army Corps of Engineers' (USACE) effort to rehabilitate and secure the aging East St. Louis levee system that provides flood protection to approxi- mately 250,000 residents and more than $4.5 billion in economic value. The project was devised and de- signed by USACE as a cutoff wall to be installed in the Metro East Sanitary District levee segment, one of the levee segments that form the East St. Louis system. The contract for the construc- tion of the cutoff wall was awarded in November 2019 to Bauer Foundation, the American subsidiary of the Bauer Group.

Sep 1, 2023

By Lynn Crayne

We used Glyoxal as the hardener, at a final concentration of 10% by volume and therefore 20% by volume in the A-Component. They worked pretty well what we did was we shaved the joints on each of the pipes when we assembled them so they wouldn't rip the packers and then we greased the packers very well going in. We had to replace some but we have any getting stuck or didn't lose any pipes.

Feb 10, 2003

By Cemal Can Maslak, Vijaya Bhushan Rao, Vidyaranya Bandi, Karsten Beckhaus

A Large Earth Cum Rock Fill, ECRF Dam is under construction at Polavaram in the state of Andhra Pradesh in India as part of an irrigation project. The Embankment crest width of the dam is 12.5m and base width is of approximately 136.75m with a stepped sloping height of 27m on both upstream/downstream sides. Once the 1.2m Thick Plastic concrete cut-off wall is constructed below the dam along the longitudinal central axis to avoid seepage, this magnificent structure will be supported on a series of Deep Mixing Columns and Stone Columns that are evenly arranged under the footprint of ECRF Dam forming a smooth transition of gradually reducing stiffness moduli of treated ground from the center of the embankment, where the foundation stresses are high, towards the edges in order to be able to progressively limit the settlements under the dam to a specified allowable limit. As such the required post treatment stiffness in case of stone columns is 2 times of the in-situ stiffness of foundation soil, whereas it is expected to be 5 times improvement for Deep Mixing as per project specifications. Laboratory testing and Field Trials undertaken successfully to verify the design.

Sep 1, 2022

By Frank Albrecht, Brian McCarthy

"The Ararat Terminal Station (ARTS) is located 190km to the north-west of Melbourne, approximately 1.7km to the north of Elmhurst Township in the Pyrenees region of western Victoria, Australia. The site occupies an area of approximately 7.2 hectare of farmland. The electricity generated by the Ararat Wind Farm is directed to the ARTS terminal station before being connected to the grid. The ARTS structural design includes more than 180 steel yard support structures, three 25m-tall gantry ‘A’ frames, three modular control room buildings, a precast transformer bund, precast fire wall structures and related foundation design. Innovative driven engineered glue laminated timber (glulam) piles in a cruciform shape were used to reduce the foundation construction time, cost and the amount of concrete used in the project. It is the first time that engineered timber piles made from farmed Australian pine trees have been used in a large-scale environmentally-friendly project. Durability of the timber was achieved by H5 treatment and the use of reinforced concrete pile caps to protect the cruciform timber piles at the ground line. A pile-driving sequence was developed based on field trials. The lateral load capacities of the piles were estimated using engineering principles and from full-scale tests in the field. This paper provides an overview of details of engineered timber cruciform piles, durability of timber piles, design information, pile construction procedures, pile-driving procedures, the testing protocol, test results and validation. The test results were compared with predictions from several methods. In addition, potential future applications of similar systems in other infrastructure projects, and opportunities for future improvements are discussed. The structural aspects of this project were presented in a previous paper at the World Conference on Timber Engineering in Vienna in August 2016. See http://wcte2016.conf.tuwien.ac.at/home/ for further information."

Jan 1, 1900

By Sailesh S. Author

The current design method for soil-cement (SC) columns improved soft clayey ground under the highway embankments assumes a slip circle failure surface shearing through the columns and the soils using a weighted average shear strength. However, the results from the laboratory centrifuge model test and numerical analysis indicate that in many cases, the SC columns fail by bending. Some researchers have proposed methods for estimating the maximum embankment loading for bending failure of SC columns, but those methods have limitations in correctly considering the internal shear stresses or not applicable for the group SC column improvement. Numerous model embankments on SC columns have been simulated by three-dimensional (3D) finite element analysis (FEA) and the mechanism of bending failure and the magnitude of the bending moment in the SC columns under embankment load has been investigated. Based on the simulated results, the design method for the estimation of the bending failure of floating SC columns has been proposed. The predicted results from the proposed method agreed with the existing field condition of one embankment in Saga, Japan reported in the literature in terms of the stability of columns. Hence the proposed method can be used for the design of floating SC columns in the soft ground.

By B. De Paoli

At Pietrafitta, between Assisi and Perugia, ENEL (Italian National Electricity Authority) has for some time been managing a power-station operated with lignite, mined from an open mine on the way to exhaustion. A new plant is under construction which is located in the mine that was filled with tailings, mainly clays, sandy silts, lignite and ashes produced by the power-station. The soil profile is shown in Fig. 1: the thickness of the made ground is around 27 m. The foundation of the new power-station is on 320 t piles, 1.20 m diameter, embedded in the cohesive base formation at a depth of 57.5 m. 2,350 piles will be constructed for a total length of 125 km. It is therefore one of the largest pile sites at present in operation in Italy. [ ]

Jan 1, 1994