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Site characterization of large hydropower projects
Get PDFHydropower plays an important role in the context of the energy transition contributing to the reduction of the CO2 emission through a permanent power production as run-of-river scheme as well as for energy storage as pump-storagescheme. Nowadays large hydropower plant designs comprise tunnel, cavern and shaft excavation work known as head race and pressure tunnel or pressure shaft. The powerhouse is often placed within a large underground cavern. The results of a ground investigation phase including the determination of in-situ parameters derived from tests in boreholes drilled from the surface are crucial for a preliminary design of the hydropower plant. Additional in-situ measurements are frequently carried out within an exploratory tunnel to confirm the first predictions and to characterize in detail the mechanical and hydraulic properties of the rock mass. Solexperts portfolio of in-situ well tests comprise the assessment of hydraulic properties vs. depth through hydraulic testing of isolated borehole sections along the borehole axes, the determination of geomechanical parameters like deformation- and Young’s modules through borehole dilatometer tests and rock stress measurements conducting hydraulic mini-frac tests. Plate load tests which use surficial loading are performed in small tunnels or test adits to measure the deformation characteristics of a rock mass on a larger scale
Measurement of soil temperature with depth using multiple sensor arrays
Get PDFAccurate measurement of soil temperature is essential for the diagnosis of various environmental processes and their impact on ecosystems. Indeed, continuous monitoring of temperature profiles with depth provides valuable understanding of the soil thermal response, which could support studies related to climate change, hydrology, agriculture, and geothermal energy. The paper describes an innovative installation procedure of temperature strings (CS225) to measure the temperature field of an undisturbed soil deposit at different depths in real time. The strings consisted of multiple temperature probes connected in series, placed at specific depths within the soil profile. The CS225 probes require little maintenance and no initial calibration, guaranteeing a high accuracy and resolution of the temperature measurements. The initial field measurements have shown a good performance of the probes, which have been able to detect the gradual decrease of soil temperature and the reduction of oscillations with depth. Further research will include the detailed analysis of the influence of ambient wind speed, solar radiation and soil moisture on the heat transfer from the ground surface to the deeper soil layers, as well as laboratory tests and numerical analysis
Investigating crushing-induced particle shape change in granular material
Get PDFHigh-pressure uniaxial compression tests were conducted under strain-controlled conditions using spherical glass beads. The study focused on investigating the compression behavior and particle fragmentation phenomena, particularly observing changes in particle size and shape resulting from fragmentation. The examination of particle shape, specifically sphericity and roundness, was emphasized. The samples comprised glass beads with uniform particle size and shape initially. It was observed that pressures exceeding 20MPa triggered particle fragmentation, leading to significant compression behavior. Notably, a softening phenomenon characterized by rapid fluctuations in compressive stress, despite a monotonic increase in strain, was observed during fragmentation. This phenomenon indicates the particles' catastrophic failure, unable to withstand the contact forces they previously sustained. Observations of particle shape revealed trends toward asymptotic distributions in cumulative curves for particle size, sphericity, and roundness. Moreover, changes in the cumulative curve of roundness were more pronounced compared to particle size and sphericity
Evaluation of Cone Resistance Results from Dutch Formula
Get PDFThe Dynamic Penetration Test (DPT) is widely applied for soil field characterization. The technique is usually appreciated as a simple and cost-effective means of determine soil resistance which can be obtained either from Newtonian or from wave equation methods. While wave equation analysis has demonstrated numerous advantages in recent decades, its adoption is constrained by the need for specific instrumentation and more complex analysis. Consequently, the simpler Newtonian analysis, and particularly the Dutch Formula specified by ISO 22476-2, remains the more commonly used approach for routine geotechnical applications. To ensure its accuracy comparing to wave equation-based methods, a field campaigns were conducted on experimental sites with various soil types. The campaigns included Cone Penetration Test (CPT), which is used as a reference tool in this study, and instrumented DPTs allowing easy application of wave equation methods. Results revealed that Dutch Formula resistance values were comparable to both CPT results and those derived from wave equation methods in most cases. In addition, DF variation formula applying energy measurement seemed to underestimate cone resistance in all case examined. The study highlights the importance of applying good practice rules to enhance DPT result
In-situ experimental tests for shallow foundation design using dynamic penetration testing method
Get PDFTo develop an advanced and innovative method for shallow foundations design with the aid of dynamic penetration testing technique, several in-situ tests are realized on various experimental sites to enrich the available database and to valid the computed results. This communication presents the field tests consisting of the Foundation Loading Tests and the Dynamic Cone Penetration Tests (DCPT): their performance, operation principles, equipment and results obtained. A direct method for bearing capacity prediction based on the measured data is also proposed, then compared to other approaches already standardized. Therefore, this study contributes to the improvement of the shallow foundations design method by providing full-scale experimental results and discussing their findings
Determination of the S-wave propagation velocity of ballast by Spectral Analysis of Surface Waves
Get PDFThe Laboratorio de Geotecnia-CEDEX uses some software and tools for studying different phenomena and performance of track sections. For this purpose, it is usually necessary to determine the S-wave (shear elastic wave) velocity of the different layers in the track section which typically are, from bottom to top: natural ground, embankment, form layer, subballast and ballast. The Laboratorio de Geotecnia-CEDEX has experimental S-wave propagation velocity (Vs) values of embankments, form layers and sub-ballast layers, obtained from several campaigns where the Spectral Analysis of Surface Waves (SASW) was applied on the different layers during the construction of several track sections. To complete the studies and to obtain Vs values for the ballast layer, two campaigns were carried out in the CEDEX Track Box (CTB), a railway testing facility where it is possible to test complete railway sections on a 1:1 scale; and a field measurement campaign on an in-service railway track. Due to the discontinuous nature of the ballast layer carrying out tests to obtain Vs presents serious problems. To avoid these problems, a new procedure was developed to obtain these values using the SASW method by installing sensors on top of the sleepers. Through the interpretation of measurements taken with the SASW technique on the ballast, the dispersion curve is obtained, and from it, the values of Vs are calculated. The results are presented in this article and are also compared with values found through a literature review obtained or estimated by other authors
30 anys de Política de Clústers de Catalunya
No full textCatalunya va ser un dels territoris pioners a nivell internacional en dissenyar i implementar iniciatives de millora de la competitivitat utilitzant els clústers. Les tres dècades d’experiència continuada han tingut des dels inicis, l’any 1992, l’objectiu essencial de millorar la competitivitat empresarial entenent el clúster com una eina i no pas com a un objectiu.
Els orígens d’aquesta metodologia els trobem el 1990 quan el professor de la Universitat de Harvard, Michael E. Porter, publicà The Competitive Advantage of Nations, llibre que va obrir la porta a la utilització dels clústers com a eina de política pública per al reforçament de la competitivitat. Catalunya va ser un dels primers llocs al món en utilitzar aquest enfocament basat en enfortir la competitivitat d’un territori mitjançant la millora de l’estratègia de les empreses i de l’entorn en el qual operen. Aquest esforç i la metodologia original que es desenvolupà a Catalunya va ser reconegut pel mateix Michael Porter en la seva obra On competition (HBS publishing, Boston, 1998). Finalment, la trajectòria de Catalunya en l’aplicació de la política de clústers ha estat recentment objectiu d’un cas d’estudi per part de la universitat de Harvard (veure Christian C.M. Ketels, Three decades of cluster policy in Catalonia: what’s next?, HBS 724404-PDF-ENG, 2023
Aquest recent cas publicat per Harvard sobre l’experiència catalana esdevé un element de reflexió òptim per aprendre del passat però sobretot per encarar el futur. Com hauria d’evolucionar la política de clústers per arribar al seu màxim potencial en el context actual? Quines aportacions pot fer a la prosperitat de Catalunya? A la intensitat tecnològica de la indústria catalana? A generar el talent necessari per aprofitar els grans reptes de futur? A un nou capitalisme més conscient?
Els seus objectius.
Descriure els factors descriptius d’una política pública en l’àmbit de la competitivitat que , malgrat la inestabilitat vinculada als canvis derivats del cicle polític, s’ha mantingut estable durant més de tres dècades.
Alhora, compartir les reflexions de futur per entendre com evolucionar la política de clústers en el context actual.
Els resultats i conclusions assolides.
Els aprenentatges dels 30 anys de política de clústers, que es descriuran en la comunicació, inclouen aspectes institucionals (treball públic-privat desplegat en xarxa), impacte econòmic (mètriques resultat del rendiment de comptes en base a una avaluació sistemàtica realitzada anualment seguint les millors pràctiques internacionals), competitivitat (estructures sectorials activades al llarg dels anys per incrementar la competitivitat de les empreses i el territori), lideratge (influència de la comunitat clúster catalana en els fòrums internacionals de referència, com Harvard, el TCI Network o la Comissió Europea)
Factors clau de l’èxit esportiu i econòmic en clubs de futbol professional
No full textJustificació del seu interès:
El futbol professional ha experimentat una transformació significativa, convertint-se en una indústria multimilionària que planteja reptes únics tant en l'àmbit esportiu com econòmic. L’interès d'aquesta comunicació radica en la necessitat d'analitzar i comprendre els factors que contribueixen al èxit econòmic i esportiu dels clubs de futbol, essencial per a la gestió sostenible i l'èxit continuat d'aquestes entitats en un entorn altament competitiu i comercial.
Objectius:
Identificar i analitzar els factors que influencien l'èxit esportiu i econòmic dels clubs de futbol professional.
Explorar la interacció entre la gestió financera i l'èxit esportiu, incloent l'impacte del fair play financer.
Proporcionar un marc analític per a l'avaluació del rendiment basat en indicadors clau obtinguts a partir de l'anàlisi de europees la Lliga espanyola durant deu temporades.
Resultats que s'espera obtenir:
Esperem demostrar relacions significatives entre la gestió financera i l'èxit esportiu, oferint una visió detallada de com les decisions de gestió afecten el rendiment dels clubs. Aquest estudi proporcionarà una base de dades robusta que destaca els indicadors de rendiment financer i esportiu que prediuen l'èxit, oferint així eines valuoses per a la presa de decisions estratègiques.
Conclusions que s'espera assolir:
La comunicació conclourà destacant la importància crítica d'una gestió financera equilibrada per al manteniment de l’èxit esportiu, i viceversa. S'espera que els resultats reforcin la necessitat de polítiques de gestió financera sostenible que no comprometin el rendiment esportiu i aportin recomanacions per a la millora contínua en la governança dels clubs de futbol professional
Gestors, fons d'inversió, capital privat i institucional com a clau del desenvolupament econòmic i social del segle XXI (Col·laboració Publicoprivada)
No full textEn una economia global amb una circulació de capital cada vegada més fluida, un món occidental amb uns fluxos d'ingressos més estables que creixents i una despesa pública creixent, ens porten a l'única confluència possible que és la col·laboració publicoprivada.
La col·laboració publicoprivada en un mercat de capitals extremadament permeable i cada vegada més professionalitzat, amb gestors de capital com a garants de l'eficiència inversora, ens donen l'oportunitat de treballar de forma constructiva i a través dels valors compartits cap a una col·laboració eficient i alineada amb l'economia productiva des de la consciència social
Piezometers: a very important instrument to which we need to pay more attention
No full textPiezometers are instruments that can produce high-quality information if suitable and effective installation and monitoring procedures are followed. In order to minimise errors and optimise quality of the obtained information, we must pay attention when prescribing the type of piezometer and its installation, as highlighted in the ISO/EN18674 standards. The use of piezometers as a geotechnical instrument is a commodity. This paper aims to exemplify how the use of piezometers can be optimised and how the most common errors can be avoided