http://hdl.handle.net/2117/593 2013-06-20T06:49:36Z http://hdl.handle.net/2117/19556 Title: An analytical solution to study substrate-microbial dynamics in soils Authors: Sánchez Vila, Francisco Javier; Rubol, Simonetta; Carles Brangari, Albert; Fernández García, Daniel Abstract: We provide an approximate analytical solution for the substrate-microbial dynamics of the organic carbon cycle in natural soils under hydro-climatic variable forcing conditions. The model involves mass balance in two carbon pools: substrate and biomass. The analytical solution is based on a perturbative solution of concentrations, and can properly reproduce the numerical solutions for the full non-linear problem in a system evolving towards a steady state regime governed by the amount of labile carbon supplied to the system. The substrate and the biomass pools exhibit two distinct behaviors depending on whether the amount of carbon supplied is below or above a given threshold. In the latter case, the concentration versus time curves are always monotonic. Contrarily, in the former case the C-pool concentrations present oscillations, allowing the reproduction of non-monotonic small-scale biomass concentration data in a natural soil, observed so far only in short-term experiments in the rhizosphere. Our results illustrate the theoretical dependence of oscillations from soil moisture and temperature and how they may be masked at intermediate scales due to the superposition of solutions with spatially variable parameters. 2013-06-14T13:59:57Z http://hdl.handle.net/2117/19510 Title: Progressive emergence of double porosity in a silt during compaction Authors: Casini, Francesca; Vaunat, Jean; Romero Morales, Enrique Edgar; Desideri, Augusto Abstract: The paper deals with an experimental investigation of water retention properties of a statically compacted unsaturated low plasticity silt. The objective is a deeper understanding of the evolution of an aggregate type fabric at different initial conditions in terms of void ratio and water content. A series of Mercury Intrusion Porosimetry tests (MIP) were performed to provide information about factors influencing fabric changes (effect of mechanical stress due to sample compaction) and fabric-properties relationships (water retention curve related to porosimetry). The arrangements of aggregation/particles are also investigated with Environmental Scanning Electron Microscopy (ESEM). The experimental data has been used to calibrate a multimodal water retention model for aggregate which is obtained by linear superposition of sub-curves of the van Genuchten type modified. By comparing the WRC obtained by MIP and under suction controlled conditions it has been found a good agreement between the two method for the drying path. 2013-06-04T18:13:50Z http://hdl.handle.net/2117/19509 Title: Laboratory experiments on swelling due to crystal growth in sulphate argillaceous rocks Authors: Deu, Amadeu; Romero Morales, Enrique Edgar; Berdugo de Moya, Iván Rafael Abstract: Crystal growth is a frequent cause of expansive deformations in natural soils, compacted soils, rocks and concrete. The sulphate crystallization in discontinuities and cracks due to evaporation of highly mineralized solutions can contribute in an important way to displacements and swelling pressures that usually appear in tunnels and deep foundations in argillaceous rocks. The present work is aimed to study the basic mechanisms that control the hydrated sulphate mineral growth in anhydritic-gypsiferous argillaceous rocks due to the evaporation of groundwater. The paper presents some laboratory works including mineralogical and micro-structural analysis, as well as the design and development of new free swelling tests which were developed focusing on the capacity to discern the role carried out by the geochemical properties of the water, the main environmental variables and the degree of cracking on undisturbed sulphate argillaceous samples from different zones of the Lower Ebro Basin (Catalonia, Spain). 2013-06-04T18:08:46Z http://hdl.handle.net/2117/19508 Title: Effects of relative humidity cycling on the hydro-mechanical behaviour of two clayey rocks from North-East Spain Authors: Pineda Jiménez, Jubert Andrés; Alonso Pérez de Agreda, Eduardo Abstract: The paper describes the results of an experimental research aimed at studying the effects of relative humidity cycling on the degradation phenomena of two clayey rocks from North-East Spain, with particular emphasis on peak shear strength, low-strain stiffness and water permeability. Undisturbed samples were subjected to an extreme relative humidity cycle (between 15% and 99%) using the vapour transfer technique, before performing triaxial compression and water permeability tests. Rock stiffness was evaluated by ultrasonic pulse tests. Test results showed clear differences in stiffness and shear strength response between undisturbed and degraded samples, highlighting the relevance of hydraulically induced degradation phenomena on this type of materials. 2013-06-04T18:03:22Z http://hdl.handle.net/2117/19507 Title: Volumetric behavior of unsaturated-reconstituted soils Authors: Burton, G. J.; Sheng, Daichao; Romero Morales, Enrique Edgar Abstract: The vast majority of unsaturated soil research is completed on compacted soils. Due to ease of laboratory testing, specimens are typically prepared dry of optimum and often with high void ratios (low dry density) to capture the phenomena of collapse. Compacted soils have significant impacts on infrastructure, but the inherent effects of structure within each sample are difficult to differentiate from the effects of suction (and degree of saturation) in the laboratory. Although significant advances have been made with techniques such as MIP and ESEM. The difficulties of producing and unsaturated sample from slurry have largely limited the amount of published literature on samples reconstituted from slurry. In this paper, the available published data sets of Jennings and Burland (1962), Vicol (1990) and Cunningham (2000) are reviewed. Predictions of the volume change behavior are then made. 2013-06-04T17:55:03Z http://hdl.handle.net/2117/19506 Title: A practical method for suction estimation in unsaturated soil testing Authors: Amaral, M.F.; Viana da Fonseca, A.; Romero Morales, Enrique Edgar; Arroyo Alvarez de Toledo, Marcos Abstract: This research presents an alternative methodology to estimate suction in triaxial tests carried out under constant water content. A preliminary determination of the retention curve is proposed using two complementary techniques, namely psychrometer measurements and mercury intrusion porosimetry results. Starting with the definition of a set of retention curves at different void ratios, an attempt is made for establishing a correspondence of the measured retention curves with the results of a high pressure isotropic compression test. From the stress-paths followed in a soil-cement specimen during isotropic compression, plotted in the void ratio-stress plane, the suction is interpolated by using the previously measured values and the evolution law describing suction as a function of the specimen’s void ratio. For the aforementioned paths, the suction for all stress state points is estimated, including for the apparent yield pressure. 2013-06-04T17:52:00Z http://hdl.handle.net/2117/19505 Title: Effect of loading and suction history on time dependent deformation of coarse crushed slate Authors: Romero Morales, Enrique Edgar; Alvarado, Clara; Alonso Pérez de Agreda, Eduardo Abstract: The paper presents the results of an experimental investigation aimed at evaluating the time-dependent compressibility of coarse crushed quartzitic slate, focusing on the effects of the previ- ous loading and hydraulic history. Long-term and large diameter compression tests under oedometer conditions were performed at different total suctions (relative humidity values) and vertical stresses but following different loading and hydraulic paths. A finding, which has practical implications in earthwork constructions, is that pre-compressing at increasing overconsolidation ratios or pre-soaking the crushed material at constant and elevated stresses leads to the progressive vanishing of long-term deformations. 2013-06-04T17:48:04Z http://hdl.handle.net/2117/19365 Title: Apoyo institucional del ICE-UPC a las dinámicas de innovación docente: Proyecto RIMA Authors: Martínez Martínez, María del Rosario; Salán Ballesteros, Maria Núria; Adam, Araceli; Darnell, Isabel; Corral Manuel de Villena, Ignacio de; Gallego Fernández, María Isabel; Portet Cortés, Esperanza; Torra Bitlloch, Immaculada Abstract: En los últimos años, desde el Instituto de Ciencias de la Educación de la Universidad Politécnica de Cataluña (ICE - UPC), se ha incentiva do l a Innovación Docente mediante múltiples iniciativas. Desde 2007, con la creación del Proyecto RIMA (Investigación e Innovación en Metodologías de Aprendizaje - Recerca i Innovació en Metodologies d’Aprenentatge) y de su entorno virtual asociado (www.upc.ed u/rima), el apoyo a la innovación docente se completa con un proyecto coordinado, que facilita la confluencia de esfuerzos de grupos de profesorado con interés en este ámbito. En la presente comunicación y partiendo de los resultados y experiencias de los últimos años en adaptación e implantación de metodologías de innovación docente en la UPC, se realiza una reflexión sobre la acogida e incidencia de esta iniciativa en la adaptación a los nuevos planes de estudio del Espacio Europeo de E ducación Superior ( EEES), y en el planteamiento de nuevos objetivos institucionales referidos tanto al tema de la participación en innovación docente como a las nuevas metodologías y a la mejora de la calidad docente. 2013-05-21T17:25:49Z http://hdl.handle.net/2117/19363 Title: Micro-measurement and monitoring system for ageing underground infrastructure (UndergroundM3) Authors: Soga, K.; Ledesma Villalba, Alberto; Roncaglia, A.; Vanícek, I. Abstract: Advances in the development of computer vision, miniature micro-electro-mechanical systems (MEMS) and wireless sensor network (WSN) offer intriguing possibilities that can radically alter the paradigms underlying existing methods of condition assessment and monitoring of ageing civil engineering infrastructure. This paper describes some of the outcomes of the European Science Foundation project “Micro-Measurement and Monitoring System for Ageing Underground Infrastructures (Underground M3)”. The main aim of the project was to develop a system that uses a tiered approach to monitor the degree and rate of tunnel deterioration. The system comprises of (1) Tier 1: Micro-detection using advances in computer vision and (2) Tier 2: Micro-monitoring and communication using advances in MEMS and WSN. These potentially lowcost technologies will be able to reduce costs associated with end-of-life structures, which is essential to the viability of rehabilitation, repair and reuse. The paper describes the actual deployment and testing of these innovative monitoring tools in tunnels of London Underground, Prague Metro and Barcelona Metro. 2013-05-21T16:25:49Z http://hdl.handle.net/2117/19322 Title: Testing a new submersible drill rig Authors: Romero, F.; Devincenzi, M.J.; Pérez Garcia, N.; Arroyo Alvarez de Toledo, Marcos; Deu, Amadeu Abstract: The paper describes the main features and initial underwater field-testing results of a remotely operated submersible drill rig designed to obtain continuous cores of soil and/or rock up to 6m long in water depths of 200m. The rig mast angle is hydraulically actuated covering 90° of altitude. This enables both a fully horizontal position used for deployment onto, and recovery of the rig from, the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters such as torque, thrust, advance, injection rate and pressure are recorded. The equipment is deployable from a variety of platforms. 2013-05-16T17:46:05Z http://hdl.handle.net/2117/19320 Title: A submersible drill rig for coring soils and rocks Authors: Devincenzi, M.J.; Pérez Garcia, N.; Samoili, K.; Arroyo Alvarez de Toledo, Marcos Abstract: The paper describes the design and initial field-testing of a remotely operated submersible drill rig able to obtain continuous cores of soil and/or rock up to 6 m long. The rig mast angle is hydraulically actuated covering 90 degrees of altitude. This enables both a fully horizontal position used for deployment onto and recovery of the rig from the seabed, as well as a fully vertical position during coring. The frame is equipped with positioning and inclination sensors for accurate register of core orientation. Coring equipment with diameter of up to 133 mm can be mounted in the rig, thus enabling the recovery of relatively large-diameter cores. The coring operation is fully instrumented and all the drill operation parameters like torque, thrust, advance, injection rate and pressure are recorded. The equipment is adapted for geotechnical investigation of the renewable energy industry, as well as pipelines, cables and dredging requiring platform or near shore site investigation. The equipment is deployable from a variety of platforms and does not require a fully-fledged drill ship. 2013-05-16T16:33:30Z http://hdl.handle.net/2117/19319 Title: Design control and monitoring of a jet grouted excavation bottom plug Authors: Eramo, N.; Modoni, Giuseppe; Arroyo Alvarez de Toledo, Marcos Abstract: Jet grouting is adopted in different geotechnical conditions to ensure provisional earth retaining and waterproofing functions at the bottom and walls of excavations. Despite careful theoretical models avail-able to predict the mechanical response of these structures, design is often carried out without adequate con-trol, i.e. by assuming ideal effectiveness of ground improvement. On the contrary, adverse effects have been documented by past experiences which can be traced back to erroneous prediction of treatments effects, inac-curate control of the execution or to unexpected responses of the surrounding environment. All these uncertainties, which become particularly critical when excavation is performed in urbanized areas, can be mini-mized by detailed preliminary field trials, accurate controls of the execution of treatments and a prompt monitoring of the surrounding area. The present paper describes this methodology applied to the design and the execution of a massive jet grouting bottom plug forming the base of a large excavation in city environment. The results of preliminary field trials are summarized to directly compare the effectiveness of different injection systems and introduced in statistical design analyses of the jet grouted structure. A detailed investigation of the movements induced at ground level by injections is also reported. To this aim, the evolution of displacements recorded around trial columns and on the area surrounding the excavation is mapped to evaluate the effects of the different adopted injection techniques. 2013-05-16T16:26:07Z http://hdl.handle.net/2117/19317 Title: SAR measurements of coastal features in the NW Mediterranean Authors: Redondo Apraiz, José Manuel; Martínez Benjamín, Juan José; Díez Rilova, Margarita; Lopez Gonzalez-Nieto, Pilar 2013-05-16T16:15:04Z http://hdl.handle.net/2117/19308 Title: Testing block samples from silty deposits Authors: Pineda Jiménez, Jubert Andrés; Arroyo Alvarez de Toledo, Marcos; Sau Valenzuela, Núria; Gens Solé, Antonio; Pérez, Norma Abstract: The paper describes the results of a comprehensive experimental program aimed to characterize block samples of silty deposits obtained from the deltaic zone of the Llobregat River ( Barcelona).Undisturbed block samples were obtained from a deep excavation taking place on interbedded sandy silts by hand retrieval. A detailed examination of the retrieved blocks, including suction measurements as well as Computed Axial Tomography (CAT) scans was performed before testing. Material characterization was complemented with identification tests carried out on representative samples obtained at different points inside the block. Finally, soil disturbance was evaluated by means of CRS oedometer tests on specimens retrieved at different depths. The spatial variability of suction (water potential) and water content was defined here based on tensiometer measurements. From CAT images the sedimentary nature of the block as well as the position and 3D distribution of heterogeneities could be detected. CRS tests showed a similar stress-strain response from which the evaluation of sample disturbance indicated the very high quality of samples tested. 2013-05-16T13:41:23Z http://hdl.handle.net/2117/19305 Title: Site characterization alternatives for numerical models of a deep excavation Authors: Sau, Núria; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio Abstract: A cut-and-cover railway tunnel site on the outskirts of Barcelona benefited from an extensive site investigation campaign. During the construction of the tunnel, the displacement of the wall as well as the of soil beneath was recorded. A 2D numerical model of the excavation sequence was established. The large amount of site investigation data allowed a systematic comparative approach. Four different soil characterization strategies were mimicked, deliberately ignoring one or another subset of the characterization data. While results from CPTu and SPT were assumed equally available to all the hypothetical designers, the extra information for one of them was only laboratory test results, for another one it was pre-bored PMT data, for the third one it was SBPM and cross-hole tests data and, finally, the last one had DMT, SDMT and cross-hole tests data as complementary information. The simulation results are obtained using the Hardening soil model. 2013-05-16T13:29:24Z