Solexperts AG

Mönchaltorf, Switzerland

Solexperts AG

Mönchaltorf, Switzerland
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Lin Z.,University Claude Bernard Lyon 1 | Tillement O.,University Claude Bernard Lyon 1 | Blanchin M.-G.,University Claude Bernard Lyon 1 | Jindal V.,University Claude Bernard Lyon 1 | And 5 more authors.
Applied Radiation and Isotopes | Year: 2017

Long term in situ diffusion experiments in the Callovian-Oxfordian mudstone (France) are designed in the context of nuclear waste management. β-emitters HTO and 36Cl radiotracers are representative of neutral and anionic species in these experiments. Studies have been carried out to design an in situ beta monitoring system in order to quantify tracer migration in the rock pore water over time. The development, design and calibration of β-emitter radiation sensors were performed. An optimised geometry was calculated for the detection chamber of 36Cl in solution (Ø×L=30×2 mm2) via Monte-Carlo N-Particle transport simulation tools. A better SNR (Signal to Noise Ratio) was obtained with YSO cylindrical crystal (Ø×L=6.5×0.5 mm2). A sensitivity of 0.21 cpm/Bq/mL was measured using 36Cl standards. The 36Cl detection limits were 18 Bq/mL and 14.2 Bq/mL after 1 h and 24 h of accumulation time respectively. Such beta sensors, placed 350 mm from the radiotracer injection borehole, could successfully discriminate 36Cl anisotropic diffusion in various directions within 4 years. It will be tested in situ and can be adapted to other in situ experience. © 2017 Elsevier Ltd

Kim H.-M.,Sejong University | Lettry Y.,Solexperts AG | Ryu D.-W.,Korea Institute of Geoscience and Mineral Resources | Song W.-K.,Korea Institute of Geoscience and Mineral Resources
Materials and Structures/Materiaux et Constructions | Year: 2014

Concrete permeability is subject to various test conditions, and on-site measurement at in situ structural scale is much preferable. This paper presents an experimental study to measure the permeability of concrete linings and their construction (placing) joints between old and new concretes using a novel in situ permeability testing system. Using the developed system, we performed in situ scale permeability tests of rectangular concrete specimens with dimensions of 500 × 500 × 2800 mm3, within which the construction joints were artificially placed. From this model experiment, we verified an effective applicability of the system to both low permeability concrete matrices and highly permeable construction joints thanks to its selective capability of gas or water permeability test, depending on the air/water tightness of tested materials. The experimental results presented in this paper also showed that the intrinsic permeability of the construction joint could be higher than that of the concrete matrices by orders of magnitude (101-104 times), but it could be reduced to as low as those of the concrete matrix by pasting a bonding agent on the interfacing surfaces. As a result of geomechanical monitoring during the experiment, the opening displacement of construction joints with relatively higher stiffness values showed a reversible deformation when the gas injection pressure was unloaded, which is much preferable in a storage performance perspective of underground lined rock caverns. © 2013 RILEM.

Kim H.-M.,Korea Institute of Geoscience and Mineral Resources | Lettry Y.,Solexperts AG | Park D.,Korea Institute of Geoscience and Mineral Resources | Ryu D.-W.,Korea Institute of Geoscience and Mineral Resources | And 2 more authors.
Engineering Geology | Year: 2012

In this paper, we introduce a novel in-situ permeability measurement system and present the results of field permeability testing using the developed system. Using a modular structural design and wide measurement range from low to high permeability, the developed system was capable of measuring in-situ scale permeabilities of concrete linings, construction joints and rock mass around excavated rock caverns. Such measurements have been extremely limited so far but are essentially required in estimating the sealing performance of underground storage caverns. The experimental results of a concrete block model test as well as field permeability measurements of concrete linings and the excavation damaged zone (EDZ) around a lined rock cavern (LRC) in a pilot plant for underground compressed air energy storage (CAES) were presented. From these experimental measurements, we could verify the effective applicability of the developed system to a wide range of measurement conditions, from the low permeability concrete lining matrix to the highly permeable construction joints and fractured rock masses around underground rock storage caverns. © 2012 Elsevier B.V.

Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2009.3.5 | Award Amount: 3.00M | Year: 2010

The aftermath of too many dramatic events involving public structures and private buildings collapse makes imperative to ask ourselves whether anything can be done to mitigate their effects or avoid them and save the lives taken as a result of their occurrence. Wireless sensor network (WSN)-based systems for structural health monitoring could be the answer to this crucial question were they able to provide long lasting monitoring and robust and reliable data delivery as requested by increasing safety demands.This is unfortunately unavailable today.The GENESI project proposes research addressing all the critical barriers and challenges that prevent the application of WSNs for monitoring structures, buildings and spaces. In particular, by combining new hardware and software design, the GENESI will produce systems for structural health monitoring that are long lasting, pervasive and totally distributed and autonomous.New wireless sensor nodes will be build that are capable of achieving virtual infinite lifetime through a well-balanced combination of cutting edge technologies, such as energy harvesting from multiple sources, the first small factor fuel cells, low-cost radio triggering for minimizing idle energy consumption and algorithms for smart interference management.New software will complement the GENESI hardware in the quest of long lasting system lifetime by taking into account the when and how much of energy availability. At the same time, end user requirements will be met according to a newly defined application driven Quality of Service concept.Novel task allocation algorithms, cross-layer protocol stacks, situation awareness and context discovery mechanisms complete the definition of a system that addresses the major challenges of the ICT theme of FP7. Finally, involving end users directly into the research cycle as key players,GENESI is poised to address realistic\nsocietal needs while fostering technology transfer and market exploitation.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: Fission-2009-1.1.1 | Award Amount: 6.53M | Year: 2010

The main aim of the project PEBS (Long-term Performance of the Engineered Barrier System) is to evaluate the sealing and barrier performance of the EBS with time, through development of a comprehensive approach involving experiments, model development and consideration of the potential impacts on long-term safety functions. The experiments and models cover the full range of conditions from initial emplacement of wastes (high heat generation and EBS resaturation) through to later stage establishment of near steady-state conditions, i.e. full resaturation and thermal equilibrium with the host rock. These aspects will be integrated in a manner that will lead to a more convincing connection between the initial transient state of the EBS and its long-term state that provides the required isolation of the wastes. The work proposed within the project builds on existing knowledge and experience generated during recent years and supported by ongoing nat. and EC research programmes. The project pretends to provide a more complete description of the THM and THM-C (thermo-hydromechanical-chemical) evolution of the EBS system, a more quantitative basis for relating the evolutionary behaviour to the safety functions of the system and a further clarification of the significance of residual uncertainties for long-term performance assessment. The importance of uncertainties arising from potential disagreement between the process models and the laboratory and in situ experiments to be performed within PEBS, and their implications for extrapolation of results will be reviewed, with particular emphasis on possible impacts on safety functions. In addition to the scientific-tech. aim, the consortium will spread the essential results to the european scientific community and Canada, Japan and China, use its expertise for public information purposes, and promote knowledge and technology transfer through training. WP 5 brings together activities concerning dissemination and training.

Manceau J.C.,Bureau de Recherches Géologiques et Minières | Tremosa J.,Bureau de Recherches Géologiques et Minières | Audigane P.,Bureau de Recherches Géologiques et Minières | Lerouge C.,Bureau de Recherches Géologiques et Minières | And 4 more authors.
Water Resources Research | Year: 2015

A new in situ experiment is proposed for observing and understanding well integrity evolution, potentially due to changes that could occur during a well lifetime. The focus is put on temperature and pressure stresses. A small section of a well is reproduced at scale 1:1 in the Opalinus Clay formation, representative of a low permeable caprock formation (in Mont Terri Underground Rock Laboratory, Switzerland). The well-system behavior is characterized over time both by performing hydro-tests to quantify the hydraulic properties of the well and their evolution, and sampling the fluids to monitor the chemical composition and its changes. This paper presents the well integrity assessment under different imposed temperature (17-52C) and pressure (10-28 bar) conditions. The results obtained in this study confirm the ability of the chosen design and observation scale to estimate the evolution of the well integrity over time, the characteristics of the flow along the well-system and the reasons of the observed evolution. In particular, the estimated effective well permeability is higher than cement or caprock intrinsic permeability, which suggest preferential flow pathways at interfaces especially at the very beginning of the experiment; the significant variations of the effective well permeability observed after setting pressure and temperature stresses indicate that operations could influence well integrity in similar proportions than the cementing process. © 2015. American Geophysical Union. All Rights Reserved.

Cailteau C.,University of Lorraine | Cailteau C.,Andra Inc | Pironon J.,University of Lorraine | De Donato P.,University of Lorraine | And 4 more authors.
Analytical Methods | Year: 2011

The French National Radioactive Waste Management Agency (ANDRA) has recently developed a new experimental set-up which allows sampling water from marl rock formations, together with an in situ characterisation of the composition and migration mechanisms of the gases dissolved in the marl porewater. Gases and liquids are collected from vertical borehole drillings in underground laboratories. The analytical design, Fourier transformed infrared spectroscopy based, allows powerful and long term on-line monitoring of gases released by low-permeability media. The IR system is designed to cope with the unfavourable measurement conditions occurring in an experimental underground laboratory (moisture, dust, etc.). Because the working conditions in such an underground laboratory make complete purging of the IR spectrometer difficult, the IR spectra of geological gases are often perturbed by contributions from atmospheric CO2 and water vapour. The metrology aspect is based on an IR low resolution sensor equipped with two measurement compartments. In the internal compartment linked to the borehole layout, gases are monitored on-line through a cell with a variable optical path, whereas in the external compartment, atmospheric CO2 is measured through a short open path configuration. The experimental method and data processing procedure used to determine the real partial pressure of CO2 arising from the marl rock formation are described in this paper. Results of the on-line gas (CO 2 and CH4) monitoring conducted in the Mont Terri underground laboratory are presented and compared with punctual gas chromatography analyses. © 2011 The Royal Society of Chemistry.

Kech M.,Solexperts AG | Naterop D.,Solexperts AG | Senti R.,Nordostschweizerische Kraftwerke AG NOK
Rock Engineering in Difficult Ground Conditions - Soft Rocks and Karst - Proceedings of the Regional Symposium of the International Society for Rock Mechanics, EUROCK 2009 | Year: 2010

In-situ investigations were carried out for large power house caverns of the future pump storage power station Linth-Limmern, Canton Glarus, Switzerland. To investigate the bedrock at the cavern locations 10 horizontal to upward vertical inclined 50-130 m deep boreholes were drilled from an exploration tunnel and from two cross cuts. Many hydraulic and geotechnical borehole tests were performed. To estimate the hydraulic permeability in upwardly inclined boreholes two custom-made four-fold groundwater multi-level test systems were designed and built. These systems allow boreholes to be saturated so that hydraulic heads of the isolated borehole sections could be monitored and tested. The systems proved to be time- and cost-effective. The preferred in-situ testing provided site specific hydraulic and rock mechanical properties that were an essential element for design, tender and future construction of the caverns. © 2010 Taylor & Francis Group, London.

Steiner P.,Solexperts AG | Yeatman R.,Solexperts AG
Rock Engineering in Difficult Ground Conditions - Soft Rocks and Karst - Proceedings of the Regional Symposium of the International Society for Rock Mechanics, EUROCK 2009 | Year: 2010

Construction projects are becoming more challenging and require as much instrumentation information as possible. Two new types of instruments have been developed by Solexperts to satisfy these needs. Both instruments have been field proven. The MagX extensometer is based on the magnetostrictive measurement principle. The displacement of 20 positions along a 15 m curved or straight measuring line can be simultaneously measured with high precision. The instrument is configured as a manual or automatic device. The Reverse Head Extensometer (RHX) continuously monitors the propagation of deformation during excavation providing important continuous time-relative information about excavation activities to control the excavation process, optimize design and site activities. It consists of up to 20 extensometer modules. The data logging head is located at the deepest point of the borehole instead of at the surface. This reverse configuration allows collection of continuous time-relative data as its modules are successively destroyed by the excavation. © 2010 Taylor & Francis Group, London.

Rocks containing clay and anhydrite exhibit the property of increasing their volume by absorbing water. The paper first discusses the mechanisms causing swelling and outlines their effects on tunnels. Next the hazard scenario of heaving of the tunnel tube as a whole, the structural consequences of this and the concept of the Modular Yielding System for tunnelling in stretches where heave is unavoidable are discussed. Taking the case of the Chienberg road tunnel in Switzerland, the paper also reports on experience during construction and field measurements after putting the repaired sections into operation. Special attention is given to the technical aspects of yielding supports with cement as a basic constituent for loads up to 10 MN and a yielding capacity of up to 50%. © 2010 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

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