Case Studies: Thessaloniki Metropolitan Railway (Greece)

Objective
Thessaloniki Metro is considered as the most extensive transport project in Northern Greece underway and is expected to be completed in three construction phases. At the moment, Phase 1 and Phase 2 of the project are in progress. Phase 1 involves the construction of the base underground line. The Line consists of two independent single-track tunnels, which form a network with an overall length of 9.6km. Along its length, 13 modern center platform stations will serve the 18 fully automatic driverless metro trains which are expected to carry 18000 passengers per hour in each direction. The 7.7km section constructed by means of two Tunnel Boring Machines has already been completed. The remaining section of the base line will be constructed by applying the Cut and Cover method. Com-pletion of Phase 1 is expected by the end of 2020.

The Challange
An integrated system consisting of HDPE geomembranes (1.5mm and 2.0mm thick) was qualified for waterproofing (i) the bottom and the lateral concrete walls of the stations and (ii) the shell of the tunnels. Needle-punched nonwoven geotextiles weighing 500gr/m2 and 800gr/m2 were specified as cushions for protecting the geomembranes.
At the formation level (under the concrete floor of the stations), a 140gr/m2 needle-punched nonwoven geotextile was specified to separate the existing soil at the bottom of the excavation from the drainage layer consisting of a typical 30cm thick base course gravel. Over the aggregates, the installation of the waterproofing system and the construction of each station was planned to follow.

The Solution
Following the specifications of the design for cushioning materials, Thrace Nonwovens & Geosynthetics provided needle-punched nonwoven geotextiles weighing 500gr/m2 and 800gr/m2 namely P500NW and P800NW, respectively. The geotextiles were used to protect both sides of the geomembranes from damage due to contact with either the coarse particles of the drainage layer or the protrusions on the rough concrete/shotcrete surfaces. A 140gr/m2 needle-punched nonwoven geotextile, under the trade description S12NW, was provided to act as a separator. The specific geotextile had the appropriate hydraulic characteristics to serve efficiently as filter for the aggregate layer, as well.

After works resumed in March of 2016, more than 150.000 sqm of THRACE NG nonwoven geotextiles have been installed all along the base underground line.

Figure 1: View during construction

Figure 2: Geomembrane placement on top of the cushion geotextile

Figure 3: Cushion geotextile installation

Figure 4: Spreading of the aggregates upon the geosynthetic separator

Further information
For more information on Thrace products and systems, visit www.thracegroup.com

Case Studies: Stabilisation of R28 Krugersdorp Route

After assessing several different products to solve a stabilisation and drainage problem on the R28, a provincial route connecting Krugersdorp and Vereeniging in Gauteng, Calliper Consulting Engineers determined that Kaytech’s Rock-Grid PC would provide the optimum solution.

With rehabilitation underway along this Westonaria section of the R28, it was discovered that a low point of the road traversing a stream would require robust reinforcement and drainage to prevent recurrence of base layer failure and potholes caused by groundwater pressure. Besides RockGrid PC, specified for reinforcement, Kaytech’s world renowned bidim geotextile was specified as a filter for the subsoil drains.

 

1. base prep
 

2. first roll going out
 

3. 2 x full rolls out on base
 

4. 3rd roll coming out

RockGrid PC is the first composite, reinforcing geotextile to be manufactured in South Africa. The combination of a nonwoven layer in conjunction with high tenacity, bi-axially orientated, multi-filament polyester yarns, guarantees its unique characteristics; the nonwoven geotextile component offers optimum hydraulic characteristics and high resistance to installation stresses, while its high tensile modulus provides excellent reinforcement characteristics and minimum deformation. RockGrid PC provides sufficient drainage capacity to drastically reduce flowpaths in the rein-forced soil and, compared to polyethylene grids, polypropylene grids or woven fabrics, it demonstrates an extremely low creep tendency.

Chavani Construction was awarded the contract for the project which culminated in the installation of 8 000 m2 of RockGrid PC 50/50, as reinforcement between the in-situ sub-grade and the new pavement layers as well as 1 760 m2 of bidim A2 as filter for the subsoil drains, over the low lying section of road.

Manufactured from 100% recycled polyester, bidim is a continuous filament, nonwoven, needlepunched geotextile used worldwide in a variety of applications. The needlepunching process imparts several advantages including appreciable thickness, high porosity and a high drainage capacity in both the transverse and normal to the plane.

As a reinforced separation layer RockGrid PC 50/50 was simply installed directly over the saturated sub-grade, thereby preventing contamination of the selected materials above and providing improved bearing capacity. Experience has shown less fill material is required when using RockGrid PC 50/50 as a reinforced separation layer.
In addition to RockGrid PC and bidim, 804 metres of Kaytech’s robust FloPipe 110 mm were installed in the roadside subsoil drain which was designed to collect and direct groundwater flow into the nearby stream. Manufactured from the highest quality HDPE available, FloPipe is optimally slotted for maximum infiltration with minimal blockage. The twin-wall sandwich design provides strength and flexibility while the smooth inner wall ensures high flow velocity and the corrugated outer wall is able to withstand substantial confining pressure.
Although the final result of this project could not be assessed due to the remainder of the R28 being under construction, Kaytech can confidently assure the Gauteng Department of Roads and Transport that the combination of these high performance products will provide superior subgrade stabilisation and roadside drainage.

Further information
For more information on Kaytech products and systems, visit www.kaytech.co.za

Case Studies: Use of Drainage Geocomposites for Dewatering Application in Phosphates Concentrator Pounds – Khourigba, Morocco

DRAINTUBE’s Function:
Drainage and filtration of the sludge of the pond in order to
– Increase water removal from sludge,
– Limit the water consumption,
– Limit the covered area of storage pond,
– Limit the impact of water fluctuations on slopes by avoiding soil erosion.

Project history:
OCP (Chérifien Phospates Office) is an operator of phos-phate mines in Khourigba. The enrichment of phosphates in the MEA laundromat leads each day to the production of 24,000 m3 of washing and flotation sludge. This sludge contains between 70 and 80% of water, 80 to 85% of this water is recovered from the decanters and the remainder is evac-uated as thickened sludge to ponds. OCP wanted to cover the traditional pond with a solution to increase the water removal from sludge and pre-serving the slopes of ponds from the soil erosion. This request also comes within the framework of the COP 22 which took place in Morocco in 2016. 

AFITEX, with its strong experience on the drainage system, the DRAIN-TUBE geocomposite, chemically inert and that a filtration layer to collect a clean water at the end of the collector pipes with a suspended partic-ulate matter <1% required for a reuse of this water in the phosphate extraction.

Product’s description:
The Draintube 450 FT1 D20 is an association of 2 needle-punched geotextiles (one filter and one drainage layer) with a mini-drain network. The filter layer is designed to ensure a filtration without clogging by the sludge.

Manufacturing method:
Components are bonded by needle-punching. This process is hydraulic friendly and do not damage the filtration layer characteristic.Product can be peeled in order to separate the filter layer so as to make easier the product over lap, ensuring filtration layer continuity.
Project management and contractor: OCP – Morroco
Area: 6 300 sqm Date: 2015

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Further information
For more information about ACE Geosynthetics, visit www.afitex.com or contact afitex@afitex.com

16th Geotechnical Portuguese Conference – Azores Islands, Portugal, 27 – 30 May 2018 – Special Session on Geosynthetics

The 16th Geotechnical Portuguese Conference will be held in the Azores Islands, in the city of Ponta Delgada, from 27 to 30 May 2018 and is being organized by the Regional Laboratory for Civil Engineering (LREC) of the Azores, in cooperation with the Portuguese Geotechnical Society. The conference venue is the campus of the University of the Azores. Azores consists of nine islands of volcanic origin located in the middle of North Atlantic and characterized by natural landscapes of volcanic craters and lakes.

This conference is the main event of the Portuguese Geotechnical Society, which is held biennially, integrating the areas of engineering geology, soil and rock mechanics. The main topic of the conference is “Geotechnics, Natural and Geotechnical Risks and Sustainability”. This conference edition is organized in conjunction with the 6th Geotech-nical Portuguese-Spanish Workshop under the theme of “Geotechnical Works in Volcanic Terrains”.

The Portuguese Chapter of the International Geosynthetics Society will organize a special session on geosynthetics integrating the program of the conference.
For more information: https://sites.google.com/civil-event.pt/16cng

Geotextile Session at the Middle East & North Africa Symposium – Dubai, 6 – 7 February 2018

Opening Session

On 6 & 7 February 2018 EDANA, the leading global association serving the nonwovens and related industries, welcomed over 200 delegates from more than 100 companies to Dubai for the fourth edition of the region’s premier conference for the nonwovens industry.

The symposium and exhibition featured expert analysis on market outlook, product innovation, demographic trends and sustainability initiatives over the two-day event, with dedicated sessions on geotextiles, raw material trends and nonwovens applications in different sectors.

The significant potential for global development of the geotextiles market was highlighted and confirmed by the level of interest in the companies attending. Presentations covered a wide range of topics related to nonwoven geotextiles including market developments, raw materials, innovations in nonwoven bonding technologies and the application of geosynthetics in construction, road infrastructure, coastlines, environmental protection, ground stabilization, improving the durability of con-crete and roofing.

Keynote Lecture given by Daniele Cazzuffi

Among different sessions, there was a well-at-tended afternoon session on geotextiles in the Middle East, moderated by Daniele Cazzuffi, IGS Past President, CESI SpA (Italy), who also presented the Keynote Lecture:
Geotextiles in the geosynthetics world: reinforcement, filtration and mechanical protection functions and applications.
The featured presentations were the following:
• The use of geosystems in coastline protection, by Edwin Zengerink– Tencate (the Netherlands)
• Ground stabilization with geogrids and geotextiles:the Rabab Harweel integrated project case study’by Puthiya Veettil Jayakrishnan– Maccaferri Middle East (United Arab Emirates
• Nonwovens Controlled Permeability Formwork liners improve lifetime of the Sheikh Jaber Al-Ahmad cause-way in Kuwait by Michael Moeller – Fibertex (Denmark)
• Use of nonwoven geotextiles for the protection of geomembranes in basement construction and roofing: differ-ent case histories in UAE by Arcangelo Mariano – Edilfloor (Italy).
Feedback from participants throughout the event emphasised satisfaction with the support provided to the industry and the many opportunities to meet with peers. EDANA General Manager, Pierre Wiertz, was very satisfied with a hosting another successful event in a key region for geotextiles and nonwovens in general “In addition to providing another successful platform for business development in the region, EDANA concurrently held its first ever board meeting outside of Europe here in Dubai, a testament to our reach and commitment to cater to the needs of our members and their markets”.

Further information on the symposium, including the detailed programme and the complete updated participation list, is available on the following link:
https://www.edana.org/education-events/conferences-and-symposia/event-detail/mena-symposium-2018/

Geotextiles Sessions Speakers and EDANA Organisers

 

Reported by
Seán Kerrigan, Communications & Media Relations Executive, EDANA, Brussels

XVI Croce Lecture Delivered by Kerry Rowe – Roma, Italy, 13 December 2017

The Italian Geotechnical Society (Associazione Geotecnica Italiana – AGI) organized the annual Conference on the 13th of December 2017 at the “Auditorium Antonianum” in Roma : the lecture is dedicated to the memory of the late Professor Arrigo Croce, who was the first professor of Soil Mechanics and Geotechnical Engineering in Italy, Presi-dent of the AGI, vice-President for Europe of the ISSMFE and co-founder of the Technical Committee devoted to the Geotechnical Aspects of Preservation of Historic Sites.

The Croce lecture 2017 was delivered by Kerry Rowe, Queen’s University – Canada and Past President of IGS, with the title: “Environmental Geotechnics: Looking Back, Looking Forward”.
The conference was opened with the greetings from Nicola Moraci, President of the Italian Geotechnical Society AGI, and the Croce lecturer was introduced by Daniele Cazzuffi, President of AGI-IGS, the Italian Chapter of IGS, who highlighted the important contributions of Prof. Rowe in the area of environmental geotechnics and engineering with geosynthetics.

The outstanding lecture provided an excellent state-of-art on lessons learned from the past and provided future per-spectives in different topics of the environmental geotechnics, for example the contaminant migration in compacted clay liners, the behavior of the leachate collection systems, the geomembranes long term performance both in con-taminated sites and also in landfill applications and the interaction between harsh climate and composite liners.

All of these topics were discussed from the theory to practice and vice versa, which provided a better understanding of the phenomena and the relevant factors which influence it.

More than 200 geotechnical professionals from different sectors including universities, public institutions, enterprises and contractors came from different parts of the world to gather together for this special event.

Nicola Moraci closed the session with the announcement of the new Croce Lecturer for the following year, which will be Augusto Desideri, from the “Sapienza” Roma University.
The annual conference closed with a light buffet where all the participants could spend a nice time together and have the chance to exchange traditional greetings for the coming New Year.
The written versions of the Croce lectures from the past lecturers can be downloaded from the website of AGI (http://www.associazionegeotecnica.it/rig/croce_lecture)

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7th ICEGE (International Conference on Earthquake Geotechnical Engineering) – Roma, Italy, 17 – 20 June 2019

After the increasingly successful conferences held in Tokyo (1995), Lisbon (1999), Berkeley (2004), Thessaloniki (2007), Santiago (2011), and Christchurch (2015), the Italian Geotechnical Society (AGI) on appointment by the ISSMGE Technical Committee 203 (‘Earthquake Geotechnical Engineering and associated problems’) is delighted to announce that the city of Roma will host the 7th ICEGE (International Conference on Earthquake Geotechnical Engineering) in June 2019.

As in the previous editions, the conference topics will address through general and parallel sessions the most recent developments in earthquake geotechnical engineering, stimulating fruitful technical and scientific interaction with the fields of seismology, geophysics, geology, structural and infrastructural engineering.
Among the various topics, there is also this one: Ground improvement, reinforced soil structures and geosynthetics, of particular interest for IGS members.

The ‘eternal city’ of Roma is one of the most attractive and symbolic venues in the world, thanks to its impressive cultural heritage, the pleasant weather, its extraordinary social life, not to mention the taste of the Italian food.

Transportation to and through Roma is very effective thanks to two International Airports, high-speed railways and underground city trains.

Roma can count on a variety of accommodation facilities to host the conference delegates, from Luxury hotels to B&Bs.

Pre- and/or post-conference events are also planned, including technical visits to sites affected by historical to most recent earthquakes.

Call for abstracts:
The Organizing Committee of the 7th ICEGE invites all interested geotechnical professionals and academics to submit abstracts for the conference.
All abstracts will be reviewed by the Scientific Committee and, if accepted, the author/s will be asked to submit a full paper which will be assigned to the appropriate session based on the author’s application and program requirements.

Abstracts submission deadline: 7 May 2018.
We invite authors to submit abstracts in time, this will help to conclude the review process in due time, thus avoiding delays of the whole editorial process.
Abstracts must be written in English
All abstracts must be submitted only via the online submission system.

Authors must fill out all abstract details and authors’ information following the online abstract submission procedure. Each abstract must include the paper title, authors’ names, affiliations and e-mail addresses. Submitting authors will be asked to select at least two topics among the list proposed for the conference.

It is advised to prepare an ‘offline draft’ to help the online submission by copying and pasting the required fields (title, authors, affiliations, emails, reference conference topics, text).

The maximum number of words for the text is 400. Title, authors, affiliations, emails and topics will not be counted in the 400 word limit. Figures and tables are not permitted. References are not necessary.

Acknowledgment of submission will be sent to the e-mail address provided by the submitting author. Please make sure that a confirmation e-mail is received after making the submission. If this e-mail confirmation is not received, it means we have not received the abstract.
It is the responsibility of the authors to ensure the accuracy of the abstract.

At least one author of each accepted paper must register to the conference. A paper fee of 100,00 Euros must be paid for any additional paper submitted by the same author. Any additional co-authored paper can be submitted by another registered co-author or, as an alternative, a paper fee of 100,00 Euros must be paid for each additional co-authored paper. Accepted papers will be included in the digital conference proceedings, provided the registration fee, or paper fee is paid.

USB Card Proceedings will be published by CRC Press / Balkema, Taylor & Francis Group. Since we are aware of the importance, for academics and authors, of the indexing of their works, the Editor will send the Proceedings to the indexing services (Scopus, EI and Compendex).

Organizer:
AGI (Italian Geotechnical Society) and TC 203 of ISSMGE

Contact Information:
Contact person: Susanna Antonielli
Address: AGI – Viale dell’Università 11
Phone: +39 06 4465569
Fax: +39 06 44361035
Email: info@7icege.com
Website: http://www.7icege.com

Reported by
Nicola Moraci, AGI President and IGS member, and Francesco Silvestri, Chairman of the 7th ICEGE

Short Course and Workshop by Prof. Dov Leshchinsky – Napoli (Italy), 15 March 2018

A Short Course and a Workshop were delivered by Dov Leshchinsky (Emeritus Professor at University of Delaware, USA) in Napoli, on 15th March 2018. Both the initiatives were aimed to gather professionals and scholars of the various fields of Geotechnical Engineering interested in geosynthetics and related applications. Particularly, the Course was devoted to young participants (younger than 36 years).

The Course and the Workshop were organised by Stefano Aversa (University of Naples Parthenope), Sabatino Cuomo (University of Salerno), Sergio Gobbi (Engineers’ Association of Naples), under the auspices of the Italian Geotechnical Society (AGI) and of the Italian Chapter of IGS (AGI-IGS), with the logistic support of Sabrina Moretti (University of Naples Parthenope) and Lorenzo Frigo (Geosintex srl).

Dov Leshchinsky is a worldwide well-known expert in the field of geosynthetics, with more than 40 years of experience in Geotechnical Engineering, computer programming and numerical methods, more than 30 years of teaching at University, and over 100 refereed papers, many with results of numerical analysis leading towards advances in design methods.

The 3 hours lasting Short Course titled “Geosynthetic Reinforced Soil Walls and Slopes: Theory and Application” provided an overview of modern soil reinforcing technology with an emphasis on geosynthetics. The key topics were the various available reinforcing materials, the facing components, and construction techniques. The methodologies to calculate the strength and layout of reinforcement in walls and slopes were also presented for potential various limit state failures of a reinforced structure. Attention was also given to the prediction of long-term performance of structures. More than 40 attendants were present, the most coming from Italy but also from other European Coun-tries.

The 3 hours Workshop was delivered into two parts. During the Part 1 titled “Limit State Design Framework for Geosynthetic Reinforced Soil Structures” Prof. Leshchinsky proposed a new design method based on limit equilibrium analysis and Factor of Safety (FS) Map tool. As main novelty, it was shown that the proposed design method allows attaining attain a prescribed constant FS at any location in the reinforced soil mass, providing complete information for both slip surface, reinforcement loading and connection load. The Part 2 “Lessons Learned from Failed MSE Walls” of the Workshop focused on five case histories of failed MSE walls, spanning from metallic and geosynthetic reinforcements, with the facing made of steel mesh, small concrete units, or large reinforced concrete panels, and with different, simple or more complex geometry. It is shown the likely reasons for the failures were design error and/or poor construction. Not surprisingly, it was also shown that the cost of repair was far more expensive than the savings due to skimped construction. All of these topics were discussed at the end of the Workshop moving from experience to theory and vice versa focusing on the main factors playing a role in short- and long-term behaviour of real reinforced structures in both cases of well-designed or dramatically failed structures. Out of more than 90 par-ticipants, more than 70 were professional engineers with the others being PhD students.
Memories of Short Course and Workshop by Dov Leshchinsky in Napoli (Italy)

Reported by
Stefano Aversa (University of Naples Parthenope and IGS member) and Sabatino Cuomo (University of Salerno and AGI-IGS Board member)

Technical Day – Geosynthetics Applications and Solutions in Roads – Marne-la-Vallee, France, 15 March 2018

Organised by the French chapter of IGS every two years, a technical day about geosynthetics applications and solutions (in roads this year) took place in Marne-la-Vallee (near Paris) in 2018 March 15th. This technical day welcomed more than fifty attendees who are experts, engineers, researchers and technicians, mainly from France.

During this technical day, experts highlighted a state of an art of the use of geosynthetics in roads and highways projects. More specifically, engineers presented some practical cases as the use of geosynthetics to prevent cracks raising from sub-structure in the roadway, the use of reinforcing geosynthetics in airport runway and highway, the use of geomembranes in various underground structures, the use of geosynthetics solutions for drainage and reinforcing applications. Lastly, a comparison between traditional solutions using granular materials and geosynthetics, in terms of environmental footprint, under-lined a major benefit of geosynthetics for sustainable development. The presentations, in French, are available for free.

Reported by
Guillaume Stoltz, Assistant General Secretary of French Chapter of IGS

Geosynthetics 2019 Conference: Houston TX, USA, 10 -13 February 2019

Calling all Civil, Environmental & Geotechnical Engineers & Academics: Hundreds of geotechnical professionals come together to write, peer review, publish and present the latest research and case studies. This is your opportunity to be part of one of the industry’s most respected events, Geosynthetics 2019.
This conference will be supported by IFAI and IGS North America and under auspices of IGS.

For more Information visit the website: geosyntheticsconference.com