A textural classification of argillaceous rocks and their durability

Argillaceous rocks can display a wide range of durability behavior after excavation and in cut slopes. In this paper, we propose a classification of argillaceous rocks based on their textural characteristics. Three main components of the classification scheme are the clastic framework, the fine-grained matrix, and the cementing agent. Unlike other schemes, the unlithified argillaceous sediments are included as well. The names proposed for the rocks broadly follow the existing nomenclature used in petrographic classifications. The durability of some argillaceous rock types has been assessed by taking into account a set of degradation features of the excavated slopes. It has been observed that the ratios of these textural components exert a strong control on the long-term durability of slopes

Comparative study of Spanish norms used to quantify gypsum content in civil and building construction

The "Pliego de Prescripciones Técnicas Generales para Obras de Carreteras y Puentes (PG3)" is the Spanish's Government Technical Instruction that stablishes the properties that materials used in road and bridge construction must accomplish, and includes the corresponding standardized norms to test these properties

A classification of weak rocks for their use in road embankments

Weak or soft rocks are defined as those materials whose geomechanical behavior is between hard rocks and soils. According to Giambastiani (2014), weak rocks are classified as i) primary detrital, metamorphic or volcanic rocks; and ii) secondary or evolving rocks, after the physical-chemical alteration of former hard rocks. Furthermore, weak rocks are critical geological materials since they may present undesirable behaviors, such disaggregation, fissures by cracking, crumbling, low strength and stiffness, high plasticity, slaking, fast weathering, and irreversible volume, textural and mineralogical changes (e.g., Alonso and Alcoverro, 2004)

Pérdida de suelo en laderas bajo cambio climático: procesos físicos, modelación predictiva y posibles estrategias de mitigación - El proyecto de investigación “SmuCPhy”

Este proyecto de investigación estudia los mecanismos de la pérdida de suelos en zonas montañosas mediante un método multidisciplinar y el trabajo a diferentes escalas. Uno de los objetivos principales es analizar el efecto del cambio climático sobre estos mecanismos y buscar métodos de mitigación para afrontarlo correctamente. Se utilizan datos obtenidos mediante la auscultación de un experimento físico a gran escala y cuatro laderas y cuencas naturales situadas en el Pirineo Catalán, para alimentar y validar un modelo numérico innovador que implementa un módulo de interacciones suelo-vegetación-atmósfera. Finalmente, los resultados de la auscultación y de la modelización numérica se usarán para realizar una correlación de factores condicionantes de la inestabilidad con la ocurrencia espacio-temporal de deslizamientos superficiales utilizando técnicas SIG a escala regional.Postprint (published version

Rockfalls: analysis of the block fragmentation through field experiments

Fragmentation is a common feature of rockfall that exerts a strong control on the trajectories of the generated blocks, the impact energies, and the runout. In this paper, we present a set of four real-scale rockfall tests aimed at studying the fragmentation of the rocky blocks, from the global design of the field procedure to the data analysis and the main results. A total of 124 limestone, dacite, or granite blocks ranging between 0.2 and 5 m3 were dropped from different heights (8.5 to 23.6 m) onto four slopes with different shapes (single or double bench) and slope angles (42º to 71º). The characteristics of the blocks, in particular the size, surface texture and joint condition, were measured before the drops. The trajectories of the blocks and both the initial and the impact velocities were tracked and recorded by means of three high-speed video cameras. A total of 200 block-to-ground impacts have been studied. On average, 40% of the blocks broke upon impact on the slope or on the ground, making it necessary to measure the fragments. The initial and final sizes of the blocks/fragments were measured by hand with tape, though photogrammetric techniques (UAV and terrestrial) were also used for comparison purposes. The information gathered during the field tests provides a deep insight into the fragmentation processes. On the one hand, the high-resolution slow-motion videos help to describe when and how the block breakage takes place and the spatial distribution of the pieces. On the other hand, it is possible to compute the block trajectories, the velocities, and the energy losses using videogrammetry. The results include, for instance, a block average fragmentation of 54% and 14% for the limestone and granitoids, respectively; the systematic inventory of the size fragments, which may be used for fitting the power law distributions; and after each breakage, the total angle of aperture occupied by the fragments has been measured, with values in the range 25º–145º. To figure out the different behavior of the blocks in terms of breakage/no breakage, each block-to-ground impact has been characterized with a set of parameters describing the energy level, the robustness of the substrate, and the configuration of the block contact at the impact point, among others. All these terms are combined in a function F, which is used to adjust the field data. The adjustment has been carried out, first, for the whole 200 events and later for a subset of them. The procedure and the results are described in the paper. Although the discrimination capability of F is moderately satisfactory, it is very sensitive to the test site and setup. It must be highlighted that these field tests are a unique source of data to adjust the parameters of the numerical simulation models in use for rockfall studies and risk mitigation, especially when fragmentation during the propagation is considered.The authors acknowledge the support of the Spanish Ministry of Economy and Competitiveness for the research projects RockRisk (BIA2013-42582-P), RockModels (BIA2016-75668-P, AEI, ERDF/FEDER, UE) and GeoRisk (PID2019-103974RB-I00/AEI/10.13039/501100011033). GeoRisk is funded by the Agencia Estatal de Investigación (AEI) on the framework of the Plan for Scientific-Technical Research and Innovation. The support of the Spanish Ministry of Education (grants to the second and third authors, codes FPU13/04252 and BES-2014-069795, respectively) and the BBVA Foundation (thirteenth author’s contract) is also appreciated. The collaboration of Canteras Hermanos Foj and Canteras Ponderosa S.A., Marc Janeras, and S. Moreno is greatly acknowledged. Finally, we thank two anonymous reviewers and the Editor who helped to improve the structure and content of the final version. Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Peer ReviewedPostprint (published version

Pérdida de suelo en laderas bajo cambio climático. procesos físicos, modelación predictiva y posibles estrategias de mitigación : el proyecto de investigación “Smucphy”

RESUMEN: Este proyecto de investigación estudia los mecanismos de la pérdida de suelos en zonas montañosas mediante un método multidisciplinar y el trabajo a diferentes escalas. Uno de los objetivos principales es analizar el efecto del cambio climático sobre estos mecanismos y buscar métodos de mitigación para afrontarlo correctamente. Se utilizan datos obtenidos mediante la auscultación de un experimento físico a gran escala y cuatro laderas y cuencas naturales situadas en el Pirineo Catalán, para alimentar y validar un modelo numérico innovador que implementa un módulo de interacciones suelo-vegetación-atmósfera. Finalmente, los resultados de la auscultación y de la modelización numérica se usarán para realizar una correlación de factores condicionantes de la inestabilidad con la ocurrencia espacio-temporal de deslizamientos superficiales utilizando técnicas SIG a escala regional. 1200Peer ReviewedPostprint (published version

The RockRisk project: rockfall risk quantification and prevention

Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slopes and cliffs. The orientation and persistence of joints within the rock mass define the size of the kinematically unstable rock volumes and determine the way how the detached mass be-comes fragmented upon the impact on the ground surface. Knowledge of the size and trajectory of the blocks resulting from fragmentation is critical for calculating the impact probability and intensity, the vulnerability the exposed elements and the performance of protection structures. In this contribution we summarize the main goals and achievements of the RockRisk project. We focused on the characterization of the rockfall fragmentation by means of the analysis of the fracture pattern of intact rock masses, the development of a fragmentation model and its integration into rockfall propagation analysis. The ultimate goal of the project is to quantify risk due to rockfalls and develop tools for the improvement of prevention and for protection from its occurrence.Postprint (published version

The Catalan Surveillance Network of SARS-CoV-2 in Sewage: design, implementation, and performance

Wastewater-based epidemiology has shown to be an efficient tool to track the circulation of SARS-CoV-2 in communities assisted by wastewater treatment plants (WWTPs). The challenge comes when this approach is employed to help Health authorities in their decision-making. Here, we describe the roadmap for the design and deployment of SARSAIGUA, the Catalan Surveillance Network of SARS-CoV-2 in Sewage. The network monitors, weekly or biweekly, 56 WWTPs evenly distributed across the territory and serving 6 M inhabitants (80% of the Catalan population). Each week, samples from 45 WWTPs are collected, analyzed, results reported to Health authorities, and finally published within less than 72 h in an online dashboard ( https://sarsaigua.icra.cat ). After 20 months of monitoring (July 20-March 22), the standardized viral load (gene copies/day) in all the WWTPs monitored fairly matched the cumulative number of COVID-19 cases along the successive pandemic waves, showing a good fit with the diagnosed cases in the served municipalities (Spearman Rho = 0.69). Here we describe the roadmap of the design and deployment of SARSAIGUA while providing several open-access tools for the management and visualization of the surveillance data.The authors wish to thank the staff from all the WWTPs monitored for their help and technical support during the sampling campaigns. The authors acknowledge the funding received from the ACA and the ASPCAT from the Catalan Government (Generalitat de Catalunya). ICRA authors acknowledge the funding provided by the Generalitat de Catalunya through the Consolidated Research Group grants ICRA-ENV 2017 SGR 1124 and ICRA-TiA 2017 SGR 1318. ICRA researchers also thank the funding from the CERCA program of the Catalan Government.Peer reviewe