Alain Rouleau | Université du Québec à Chicoutimi (original) (raw)

Papers by Alain Rouleau

International Journal of Geo-Engineering, 2017

Mine backfilling is a technique that has been used for decades in Canada and across the globe [1,... more Mine backfilling is a technique that has been used for decades in Canada and across the globe [1, 2]. This method has several advantages such as stabilizing the drifts and stopes of a mine and increasing worker safety. Backfilling serves to fill excavations in a mine and allows ore to be extracted more completely because the underground excavations have better support. Environmental benefits result from the use of tailings as backfill material: problems related to the disposal of surface tailings can be reduced as substantial quantities of potentially polluting tailings can be returned underground. This backfill material generally consists of a mixture of tailings, water and cement. The backfilling process has several technical aspects that interact with one another. This includes the hydrogeology, mineralogy and geochemistry of both the host rock and backfill material as well as the mechanical behavior of these two media. Mechanical

Tunnelling and Underground Space Technology, 2021

Failure of rock mass in deep underground excavations could be attributed to a broad range of perf... more Failure of rock mass in deep underground excavations could be attributed to a broad range of performance malfunction, from plastic yielding of rock, generation of macro cracks on the boundary of the excavation, gravity driven rockfalls or even complete stress-induced collapse. The failure criteria determine the stress level (or strain level) at which the rock mass loses its load-carrying (or strain-carrying) capacity. Determination of the state of underground stability can be successfully achieved through implementation of appropriate failure criteria within the numerical analyses' tools. The choice of failure criteria in numerical stability analysis plays a key role in defining the behaviour of an underground excavation. A failure criterion will be useful only if selected based on the correct mechanism of failure. Plus, a right choice of failure criterion, significantly reduces the errors of quantifying an excavations behaviour. Therefore, this paper offers a critical review of the most common stress-based and strain-based failure criteria used in numerical stability analysis of underground excavations. Particular attention is paid to characterize different mechanisms of underground failure and recommendations are formulated for each failure mode. In addition, this paper addresses the theoretical considerations for the applicability of different failure criteria and highlights the practical limitations for their numerical implementation.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Geomechanics for Energy and the Environment, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Rock Mechanics and Mining Sciences, 2016

The extraction of ore and minerals by underground mining or other underground workings often caus... more The extraction of ore and minerals by underground mining or other underground workings often cause ground subsidence phenomena. In urban regions, these phenomena may induce small to severe damage to buildings. We have developed vulnerability functions for determining damage to building in subsidence regions. The methodology uses Monte Carlo simulations, and existing analytical methods based on the beam theory for the evaluation of damage in the subsidence area. It allows taking into account uncertainties both on the geometrical and mechanical parameters of buildings, and on the phenomena of soil structure interaction for analytical methods. This paper focuses on uncertainties on soil-structure interaction. The determination of damage with analytical methods requires values of the horizontal strain and the deflection transmitted to buildings. But the available geotechnical parameters are the horizontal ground strain and the ground curvature; soil structure interaction parameters are ...

Journal of Geophysical Research: Solid Earth, 2007

The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface a... more The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed‐delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distri...

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992

Environment International, 2004

This paper illustrates a real environmental concern and draws attention to the fact that natural ... more This paper illustrates a real environmental concern and draws attention to the fact that natural processes can mobilize thallium (Tl), a highly toxic metal, which may enter the food chain as a ''hidden health killer'' with severe health impacts on local human population. Natural processes may be exacerbated by human activities such as mining and farming, and may cause enrichment of Tl in the environment. In geochemically anomalous areas with concentrated levels of Tl in the surface environment (bedrocks, waters, soils, and crops), such as the Lanmuchang area in southwestern Guizhou Province, China, it is essential to establish base-level values and to pay heed to the geological context of ''natural contamination,'' as high concentrations of Tl in bedrocks/ores (6-35,000 mg/kg) can lead to enrichment of Tl in the aquatic system (0.005-1100 Ag/l in groundwaters and 0.07-31 Ag/l in surface waters) and soil layers (1.5-124 mg/kg). In sensitive areas such as the Yanshang area of southwestern Guizhou, elevated natural levels of Tl from bedrocks may also cause higher concentrations of Tl in the surface environment, and thus more attention must be paid to geoenvironmental management of human activities if socioeconomic catastrophes are to be avoided. Due to high uptake of Tl by crops, Tl can be transferred from soils to crops and remarkably concentrated in food crops. Concentrations of 1-500 mg/kg Tl based on dry weight (DW) were determined in many food crops growing on Tl-contaminated arable soils from the Lanmuchang area. The daily intake of 1.9 mg of Tl from consumed food crops was estimated for the local adult inhabitant of Lanmuchang. Thus, Tl is regarded as a latent health hazard with potential risk of toxicity in humans within areas of ''natural'' contamination by Tl.

Computers & Geosciences, 2011

Understanding and managing groundwater resources require the integration of a large amount of hig... more Understanding and managing groundwater resources require the integration of a large amount of highquality data from a variety of sources. Due to the limitations in accessing information related to groundwater and subsurface conditions, the gathering of available existing information is of crucial importance when conducting a successful hydrogeological study. Here, we present an approach for the development of an exhaustive and comprehensive groundwater database through (1) the gathering of relevant sources of information relating to groundwater, and (2) the application of a quality control process in order to screen the data for accuracy and quality. This hydrogeological database is then implemented within a GIS (geographic information system) framework coupled to a Relational Database Management System (RDBMS) as a personal geodatabase (ESRI format) GIS technology. Once established, the spatial database allows a user to request the relevant data required for a specific hydrogeological study. In addition, stratigraphic data stored within the spatial database may be utilized for constructing 3D subsurface hydrostructural models. In order to achieve this objective, the software Arc Hydro Groundwater combined with the ArcGIS spatial database is shown to be appropriate for the 3D structural representation of aquifers (groundwater reservoirs). The innovative contribution of this approach in building 3D hydrostructural subsurface models from a spatial database resides in simplifying the required step-by-step processes by considering a unified compatible combination of ''RDBMS-ArcGIS-Arc Hydro Groundwater'' technologies. The proposed methodology is illustrated using data from an ongoing project aimed at developing an inventory of the groundwater resources of the Saguenay-Lac-Saint-Jean region, Quebec (Canada).

Cette étude présente d'abord le pourtour complet du maximum marin (mer de Laflamme) au Lac-Saint-... more Cette étude présente d'abord le pourtour complet du maximum marin (mer de Laflamme) au Lac-Saint-Jean (Québec) et la position du premier rivage lacustre développé pendant la remontée isostatique postglaciaire qui se poursuit toujours. Suit une discussion de l'origine possible des eaux salines diluées, localement présentes au Lac-Saint-Jean : eau marine postglaciaire, eaux sous glaciaires et vieilles eaux profondes du Bouclier canadien.

Symposium on the Application of Geophysics to Engineering and Environmental Problems 2011, 2011

Geosciences

The specific length of a tunnel (STL) and a new analytical model for calculating the block surfac... more The specific length of a tunnel (STL) and a new analytical model for calculating the block surface area of the rock mass are introduced. First, a method for determining the appropriate length of a tunnel for a numerical simulation is described. The length is then used to examine the correlation between the inflow rate to the tunnel and the block volume, the block surface area, and the fracture intensity (P32) through analytical and numerical modeling. The results indicate that the length of the tunnel should at least be equal to the least common multiple (LCM) of the apparent spacings of the joint sets at the wall of the tunnel to obtain the more reliable and immediate results for the inflow rate to a tunnel that is excavated in a fractured rock mass. A new analytical model was developed to calculate the block surface area and determine the essential joint set parameters, which include the dip, dip direction, and spacing. The determination of the rock block characteristics through n...

Geosciences

Knowledge of the stratigraphic architecture and geotechnical properties of surficial soil sedimen... more Knowledge of the stratigraphic architecture and geotechnical properties of surficial soil sediments is essential for geotechnical risk assessment. In the Saguenay study area, the Quaternary deposits consist of a basal till layer and heterogeneous post-glacial deposits. Considering the stratigraphic setting and soil type heterogeneity, a multistep stochastic methodology is developed for 3D geological modelling and quantification of the associated uncertainties. This methodology is adopted for regional studies and involves geostatistical interpolation and simulation methods. Empirical Bayesian kriging (EBK) is applied to generate the bedrock topography map and determine the thickness of the till sediments and their uncertainties. The locally varying mean and variance of the EBK method enable accounting for data complexity and moderate nonstationarity. Sequential indicator simulation is then performed to determine the occurrence probability of the discontinuous post-glacial sediments (...

Geosciences

Due to inherent variability arising from unpredictable geological depositional and post-depositio... more Due to inherent variability arising from unpredictable geological depositional and post-depositional processes, the geotechnical parameters of Laflamme sea clay deposits remain highly uncertain. This study aims to develop and apply a methodology to assess the uncertainties of geotechnical parameters using statistical distributions for a landslide-prone Saguenay Lac-Saint-Jean (SLSJ) region. We used the measured physical and mechanical parameters of Laflamme Sea clays of various locations in the SLSJ region to characterize the geotechnical parameters in a representative manner. Goodness-of-fit tests assign each physical and mechanical parameter a distribution function for their descriptive analysis. We found that the quality of these tests is significantly influenced by outliers. The detected outliers in the dataset considerably impact the distribution type and the uncertainties of the specific geotechnical parameter. Subsequently, appropriate distribution functions for each paramete...

International Journal of Geo-Engineering, 2017

Mine backfilling is a technique that has been used for decades in Canada and across the globe [1,... more Mine backfilling is a technique that has been used for decades in Canada and across the globe [1, 2]. This method has several advantages such as stabilizing the drifts and stopes of a mine and increasing worker safety. Backfilling serves to fill excavations in a mine and allows ore to be extracted more completely because the underground excavations have better support. Environmental benefits result from the use of tailings as backfill material: problems related to the disposal of surface tailings can be reduced as substantial quantities of potentially polluting tailings can be returned underground. This backfill material generally consists of a mixture of tailings, water and cement. The backfilling process has several technical aspects that interact with one another. This includes the hydrogeology, mineralogy and geochemistry of both the host rock and backfill material as well as the mechanical behavior of these two media. Mechanical

Tunnelling and Underground Space Technology, 2021

Failure of rock mass in deep underground excavations could be attributed to a broad range of perf... more Failure of rock mass in deep underground excavations could be attributed to a broad range of performance malfunction, from plastic yielding of rock, generation of macro cracks on the boundary of the excavation, gravity driven rockfalls or even complete stress-induced collapse. The failure criteria determine the stress level (or strain level) at which the rock mass loses its load-carrying (or strain-carrying) capacity. Determination of the state of underground stability can be successfully achieved through implementation of appropriate failure criteria within the numerical analyses' tools. The choice of failure criteria in numerical stability analysis plays a key role in defining the behaviour of an underground excavation. A failure criterion will be useful only if selected based on the correct mechanism of failure. Plus, a right choice of failure criterion, significantly reduces the errors of quantifying an excavations behaviour. Therefore, this paper offers a critical review of the most common stress-based and strain-based failure criteria used in numerical stability analysis of underground excavations. Particular attention is paid to characterize different mechanisms of underground failure and recommendations are formulated for each failure mode. In addition, this paper addresses the theoretical considerations for the applicability of different failure criteria and highlights the practical limitations for their numerical implementation.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Geomechanics for Energy and the Environment, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Rock Mechanics and Mining Sciences, 2016

The extraction of ore and minerals by underground mining or other underground workings often caus... more The extraction of ore and minerals by underground mining or other underground workings often cause ground subsidence phenomena. In urban regions, these phenomena may induce small to severe damage to buildings. We have developed vulnerability functions for determining damage to building in subsidence regions. The methodology uses Monte Carlo simulations, and existing analytical methods based on the beam theory for the evaluation of damage in the subsidence area. It allows taking into account uncertainties both on the geometrical and mechanical parameters of buildings, and on the phenomena of soil structure interaction for analytical methods. This paper focuses on uncertainties on soil-structure interaction. The determination of damage with analytical methods requires values of the horizontal strain and the deflection transmitted to buildings. But the available geotechnical parameters are the horizontal ground strain and the ground curvature; soil structure interaction parameters are ...

Journal of Geophysical Research: Solid Earth, 2007

The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface a... more The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed‐delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distri...

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1992

Environment International, 2004

This paper illustrates a real environmental concern and draws attention to the fact that natural ... more This paper illustrates a real environmental concern and draws attention to the fact that natural processes can mobilize thallium (Tl), a highly toxic metal, which may enter the food chain as a ''hidden health killer'' with severe health impacts on local human population. Natural processes may be exacerbated by human activities such as mining and farming, and may cause enrichment of Tl in the environment. In geochemically anomalous areas with concentrated levels of Tl in the surface environment (bedrocks, waters, soils, and crops), such as the Lanmuchang area in southwestern Guizhou Province, China, it is essential to establish base-level values and to pay heed to the geological context of ''natural contamination,'' as high concentrations of Tl in bedrocks/ores (6-35,000 mg/kg) can lead to enrichment of Tl in the aquatic system (0.005-1100 Ag/l in groundwaters and 0.07-31 Ag/l in surface waters) and soil layers (1.5-124 mg/kg). In sensitive areas such as the Yanshang area of southwestern Guizhou, elevated natural levels of Tl from bedrocks may also cause higher concentrations of Tl in the surface environment, and thus more attention must be paid to geoenvironmental management of human activities if socioeconomic catastrophes are to be avoided. Due to high uptake of Tl by crops, Tl can be transferred from soils to crops and remarkably concentrated in food crops. Concentrations of 1-500 mg/kg Tl based on dry weight (DW) were determined in many food crops growing on Tl-contaminated arable soils from the Lanmuchang area. The daily intake of 1.9 mg of Tl from consumed food crops was estimated for the local adult inhabitant of Lanmuchang. Thus, Tl is regarded as a latent health hazard with potential risk of toxicity in humans within areas of ''natural'' contamination by Tl.

Computers & Geosciences, 2011

Understanding and managing groundwater resources require the integration of a large amount of hig... more Understanding and managing groundwater resources require the integration of a large amount of highquality data from a variety of sources. Due to the limitations in accessing information related to groundwater and subsurface conditions, the gathering of available existing information is of crucial importance when conducting a successful hydrogeological study. Here, we present an approach for the development of an exhaustive and comprehensive groundwater database through (1) the gathering of relevant sources of information relating to groundwater, and (2) the application of a quality control process in order to screen the data for accuracy and quality. This hydrogeological database is then implemented within a GIS (geographic information system) framework coupled to a Relational Database Management System (RDBMS) as a personal geodatabase (ESRI format) GIS technology. Once established, the spatial database allows a user to request the relevant data required for a specific hydrogeological study. In addition, stratigraphic data stored within the spatial database may be utilized for constructing 3D subsurface hydrostructural models. In order to achieve this objective, the software Arc Hydro Groundwater combined with the ArcGIS spatial database is shown to be appropriate for the 3D structural representation of aquifers (groundwater reservoirs). The innovative contribution of this approach in building 3D hydrostructural subsurface models from a spatial database resides in simplifying the required step-by-step processes by considering a unified compatible combination of ''RDBMS-ArcGIS-Arc Hydro Groundwater'' technologies. The proposed methodology is illustrated using data from an ongoing project aimed at developing an inventory of the groundwater resources of the Saguenay-Lac-Saint-Jean region, Quebec (Canada).

Cette étude présente d'abord le pourtour complet du maximum marin (mer de Laflamme) au Lac-Saint-... more Cette étude présente d'abord le pourtour complet du maximum marin (mer de Laflamme) au Lac-Saint-Jean (Québec) et la position du premier rivage lacustre développé pendant la remontée isostatique postglaciaire qui se poursuit toujours. Suit une discussion de l'origine possible des eaux salines diluées, localement présentes au Lac-Saint-Jean : eau marine postglaciaire, eaux sous glaciaires et vieilles eaux profondes du Bouclier canadien.

Symposium on the Application of Geophysics to Engineering and Environmental Problems 2011, 2011

Geosciences

The specific length of a tunnel (STL) and a new analytical model for calculating the block surfac... more The specific length of a tunnel (STL) and a new analytical model for calculating the block surface area of the rock mass are introduced. First, a method for determining the appropriate length of a tunnel for a numerical simulation is described. The length is then used to examine the correlation between the inflow rate to the tunnel and the block volume, the block surface area, and the fracture intensity (P32) through analytical and numerical modeling. The results indicate that the length of the tunnel should at least be equal to the least common multiple (LCM) of the apparent spacings of the joint sets at the wall of the tunnel to obtain the more reliable and immediate results for the inflow rate to a tunnel that is excavated in a fractured rock mass. A new analytical model was developed to calculate the block surface area and determine the essential joint set parameters, which include the dip, dip direction, and spacing. The determination of the rock block characteristics through n...

Geosciences

Knowledge of the stratigraphic architecture and geotechnical properties of surficial soil sedimen... more Knowledge of the stratigraphic architecture and geotechnical properties of surficial soil sediments is essential for geotechnical risk assessment. In the Saguenay study area, the Quaternary deposits consist of a basal till layer and heterogeneous post-glacial deposits. Considering the stratigraphic setting and soil type heterogeneity, a multistep stochastic methodology is developed for 3D geological modelling and quantification of the associated uncertainties. This methodology is adopted for regional studies and involves geostatistical interpolation and simulation methods. Empirical Bayesian kriging (EBK) is applied to generate the bedrock topography map and determine the thickness of the till sediments and their uncertainties. The locally varying mean and variance of the EBK method enable accounting for data complexity and moderate nonstationarity. Sequential indicator simulation is then performed to determine the occurrence probability of the discontinuous post-glacial sediments (...

Geosciences

Due to inherent variability arising from unpredictable geological depositional and post-depositio... more Due to inherent variability arising from unpredictable geological depositional and post-depositional processes, the geotechnical parameters of Laflamme sea clay deposits remain highly uncertain. This study aims to develop and apply a methodology to assess the uncertainties of geotechnical parameters using statistical distributions for a landslide-prone Saguenay Lac-Saint-Jean (SLSJ) region. We used the measured physical and mechanical parameters of Laflamme Sea clays of various locations in the SLSJ region to characterize the geotechnical parameters in a representative manner. Goodness-of-fit tests assign each physical and mechanical parameter a distribution function for their descriptive analysis. We found that the quality of these tests is significantly influenced by outliers. The detected outliers in the dataset considerably impact the distribution type and the uncertainties of the specific geotechnical parameter. Subsequently, appropriate distribution functions for each paramete...