Jordi Corominas - Academia.edu (original) (raw)

Papers by Jordi Corominas

Understanding and Reducing Landslide Disaster Risk, 2020

Fragmentation in a rockfall event influence the total number of fragments, the mass distribution,... more Fragmentation in a rockfall event influence the total number of fragments, the mass distribution, and the impact energies and runouts. Then, the probability of impact and hazard characterization should consider fragmentation. A fractal fragmentation model has been proposed in order to reproduce the phenomenon. The Rockfall Fractal Fragmentation Model has been implemented in a 3D rockfall propagation simulator named RockGIS. We present the analysis of a fragmental rockfall that occurred in Mallorca, Spain. Fieldworks are carried out in order to obtain the block size distribution of the rockfall deposit. A 3D terrain model is obtained using UAV surveys and digital photogrammetric techniques. The obtained 3D point cloud is cleaned of vegetation and used to create a Digital Elevation Model (DEM). The fragmentation model parameters and the propagation simulator coefficients have been calibrated to accomplish both, the resultant block size distribution and the runout distance of the block...

Journal of Geophysical Research: Earth Surface, 2018

The analysis of seismic signals obtained from near‐source triaxial accelerometer recordings of tw... more The analysis of seismic signals obtained from near‐source triaxial accelerometer recordings of two sets of single‐block rockfall experiments is presented. The tests were carried out under controlled conditions in two quarries in northeastern Spain; in the first test (Foj limestone quarry, Barcelona), 30 blocks were released with masses ranging between 475 and 11,480 kg. The second test (Ponderosa andesite quarry, Tarragona) consisted of the release of 44 blocks with masses from 466 to 13,581 kg. An accelerometer and three high‐speed video cameras were deployed, so that the trajectories, velocities, and block fragmentation could be tracked precisely. These data were used to explore the relationship between seismic energy and rockfall kinetics (the latter obtained from video analysis). We determined absolute and relative values of seismic energy and used them to estimate rockfall volumes. Finally, the seismic signature of block fragmentation was assessed in both the frequency and time...

Jagiellonian University Press eBooks, Dec 21, 2023

The elements of the physical environment have long been the object of naming. Indeed, an area's f... more The elements of the physical environment have long been the object of naming. Indeed, an area's first inhabitants would have given names to places to satisfy their social need to locate themselves spatially and many of these names have been preserved until the present day. As such, place names reveal aspects of the landscape observed in the distant past by our ancestors. One such element of the physical environment is its geological features. Toponymy, in the case of the study of transparent place names in relation to aspects of the immediate terrain, is a useful tool in geology both for producing thematic maps and for locating and studying such features as caves, landslides and metal ores. At the same time, geology can help understand and clarify less transparent toponymic meanings and shed light on etymological hypotheses based on linguistic interpretations. This approach, supported by the compilation of background and comparative physiographic analyses of the geological characteristics of locations with similar place names, has considerable potential for identifying, recognizing and unravelling the origins of the names of many places. This paper presents a number of reciprocities identified between place names and their geology and assesses them as a tool for the recognition of physical features of the landscape.

A Rockfall is a mass instability process frequently observed in road cuts, open pit mines and qua... more A Rockfall is a mass instability process frequently observed in road cuts, open pit mines and quarries, steep slopes and cliffs. It is frequently observed that the detached rock mass becomes fragmented when it impacts with the slope surface. The consideration of the fragmentation of the rockfall mass is critical for the calculation of block’s trajectories and their impact energies, to further assess their potential to cause damage and design adequate preventive structures.

Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slo... more Rockfalls are frequent instability processes in road cuts, open pit mines and quarries, steep slopes and cliffs. Even though the stability of rock slopes can be determined using analytical approaches, the assessment of large rock cliffs require simplifying assumptions due to the difficulty of working with a large amount of joints, the scattering of both the orientations and strength parameters. The attitude and persistency of joints within the rock mass define the size of kinematically unstable rock volumes. Furthermore the rock block will eventually split in several fragments during its propagation downhill due its impact with the ground surface. Knowledge of the size, energy, trajectory. . . of each block resulting from fragmentation is critical in determining the vulnerability of buildings and protection structures.

In this contribution, we first present the tool RockGIS, which is a stochastic program for rockfa... more In this contribution, we first present the tool RockGIS, which is a stochastic program for rockfall propagation simulation that takes fragmentation into account considering fractal laws. The results of real-scale field tests and several natural rockfall events inventoried have led to a formulation of a new fragmentation model which has been implemented into RockGIS code. The parameters of the power law that define the sizes of the generated fragments are computed at each impact according to the kinematic conditions. To calibrate the model, we used data from a real-scale rockfall test performed in a quarry. The sizes of the tested blocks were measured manually. Both the size and spatial distribution of the fragments after each release were measured from the orthophotos taken with systematic drone flights. Both rockfall block size distribution (RBSD) and runout distribution obtained after the calibration process matched satisfactory field data, and the spatial distribution of the mode...

Landslides, 2017

is a mass instability event frequently observed in road cuts, open pit mines and quarries, steep ... more is a mass instability event frequently observed in road cuts, open pit mines and quarries, steep slopes and cliffs. After its detachment, the rock mass may disaggregate and break due to the impact with the ground surface, thus producing new rock fragments. The consideration of the fragmentation of the rockfall mass is critical for the calculation of the trajectories of the blocks and the impact energies, for the assessment of the potential damage and the design of protective structures. In this paper, we present RockGIS, a GIS-Based tool that simulates stochastically the fragmentation of the rockfall, based on a lumped mass approach. In RockGIS, the fragmentation is triggered by the disaggregation of the detached rock mass through the pre-existing discontinuities just before the impact with the ground. An energy threshold is defined in order to determine whether the impacting blocks break or not. The distribution of the initial mass between a set of newly generated rock fragments is carried out stochastically following a power law. The trajectories of the new rock fragments are distributed within a cone. The fragmentation model has been calibrated and tested with a 10,000m 3 rockfall that took place in 2011 near Vilanova de Banat, Eastern Pyrenees, Spain.

Bulletin of Engineering Geology and the Environment

Significant effort has been devoted during the last few decades to the development of methodologi... more Significant effort has been devoted during the last few decades to the development of methodologies for landslide hazard and risk assessment. All of this work requires harmonization of the methodologies and terminology to facilitate communication within the landslide community, as well as with stakeholders and researchers from other disciplines. Currently, glossaries, and methodological recommendations exist for preparing landslide hazard and risk studies. Nevertheless, there is still debate on the usage of some terms and their implementation in practice.In 2016, the IAEG commission C-37 established a working group with the objective of preparing a standard multilingual glossary of landslide hazard and risk terms. The glossary aims for the international harmonization of the terms and definitions with those used in associated disciplines (e.g., seismology, hydrology) while considering landslides specifically. The glossary is based on previously published glossaries, including those p...

Consideration of fragmentation during rockfalls is relevant for the assessment of hazard since it... more Consideration of fragmentation during rockfalls is relevant for the assessment of hazard since it affects the number of generated blocks, their trajectories and impact energies, which also depends on the topography. Recently many scholars have paid attention to these phenomena since there are still many uncertainties around fragmentation regarding how mass and energy are distributed after fragmentation and how trajectory dispersion affects risk analysis. We developed a specific fragmentation model (Rockfall Fractal Fragmentation Model), as well as a 3D trajectory simulator called RockGIS with the fragmentation module implemented. In this contribution, we present the calibration of our rockfall trajectory simulator, based on real scale fragmentation tests performed on a quarry.

Rock Mechanics and Rock Engineering, 2019

We present the performance of the rockfall fractal fragmentation model (RFFM) developed by Ruiz-C... more We present the performance of the rockfall fractal fragmentation model (RFFM) developed by Ruiz-Carulla et al. (2017) and based on Perfect (1997). The RFFM combines disaggregation of the initial rock mass and breakage of the blocks. The model has been upgraded as to meet the mass balance, and to generate both a continuous decreasing and scale variant distribution of fragments volumes. The input of the model may be either a single block or a rock mass characterized by its In situ Block Size Distribution (IBSD). The measured fragment size distributions of seven inventoried rockfall events, are used to calibrate the model. The results of the simulations fit well to the measured volume distributions. Our findings indicate that fragmentation is better characterized by the whole volume distribution of fragments generated and the increase of new surface area of the rock fragments. A relation has been observed between the potential energy of the first impact, the new surface area of fragments generated, and the model parameters. Although a greater number of parametric analyses and calibration exercises are required, this relation is proposed as a first approach to model rockfall scenarios.

Engineering Geology, 2017

Proceedings of the 12th International Symposium on Landslides (Napoli, Italy, 12-19 June 2016), 2016

Landslides, 2022

Fragmentation is a common feature of rockfall that exerts a strong control on the trajectories of... more 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...

Rockfalls are very rapid and damaging slope instability processes that affect mountainous regions... more Rockfalls are very rapid and damaging slope instability processes that affect mountainous regions, coastal cliffs and slope cuts. This contribution focuses on fragmental rockfalls in which the moving particles, particularly the largest ones, propagate following independent paths with little interaction among them. The prediction of the occurrence and frequency of the rockfalls has benefited by the rapid development of the techniques for the detection and the remote acquisition of the rock mass surface features such as the 3D laser scanner and the digital photogrammetry. These techniques are also used to monitor the deformation experienced by the rock mass before failure. The quantitative analysis of the fragmental rockfalls is a useful approach to assess risk and for the design of both stabilization and protection measures. The analysis of rockfalls must consider not only the frequency and magnitude of the potential events but also the fragmentation of the detached rock mass. The la...

Landslide Dynamics: ISDR-ICL Landslide Interactive Teaching Tools, 2018

We review the quantum spectral curve (QSC) formalism for the spectrum of anomalous dimensions of ... more We review the quantum spectral curve (QSC) formalism for the spectrum of anomalous dimensions of N = 4 SYM, including its γ-deformation. Leaving aside its derivation, we concentrate on the formulation of the "final product" in its most general form: a minimal set of assumptions about the algebraic structure and the analyticity of the Q-system-the full system of Baxter Q-functions of the underlying integrable model. The algebraic structure of the Q-system is entirely based on (super)symmetry of the model and is efficiently described by Wronskian formulas for Q-functions organized into the Hasse diagram. When supplemented with analyticity conditions on Q-functions, it fixes completely the set of physical solutions for the spectrum of an integrable model. First we demonstrate the spectral equations on the example of gl(N) and gl(K|M) Heisenberg (super)spin chains. Supersymmetry gl(K|M) occurs as a simple "rotation" of the Hasse diagram for a gl(K + M) system. Then we apply this method to the spectral problem of AdS5/CFT4-duality, describing the QSC formalism. The main difference with the spin chains consists in more complicated analyticity constraints on Q-functions which involve an infinitely branching Riemann surface and a set of Riemann-Hilbert conditions. As an example of application of QSC, we consider a special double scaling limit of γ-twisted N = 4 SYM, combining weak coupling and strong imaginary twist. This leads to a new type of non-unitary CFT dominated by particular integrable, and often computable, 4D fishnet Feynman graphs. For the simplest of such models-the bi-scalar theory-the QSC degenerates into the Q-system for integrable non-compact Heisenberg spin chain with conformal, SU (2, 2) symmetry. We describe the QSC derivation of Baxter equation and the quantisation condition for particular fishnet graphs-wheel graphs, and review numerical and analytic results for them.

Landslides, 2019

In this work, we present a novel quantitative geographical information system-based procedure to ... more In this work, we present a novel quantitative geographical information system-based procedure to obtain the magnitude (area) and frequency of medium to large first-time shallow slope failures. The procedure has been set up at the Barcedana Valley, in the Tremp Basin (Eastern Pyrenees). First, pixel-based susceptibility classes were defined using a slope stability index obtained with the physically based model SINMAP. The frequency calculated from the number of first-time failures recorded during the last 60 years was then assigned to each susceptibility class. We devised a procedure to estimate the size of potential failures by means of the aggregation of pixels within the boundaries of morphological slope units, optimized for the purpose. Finally, the landslide hazard was prepared using the magnitude-frequency matrix. Results show that a proper pixel clustering has been carried which avoids the generation of small groups of pixels with different susceptibility degrees within the sa...