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Abstract. Plane failure along inclined joints is a classical
mechanism involved in rock slope movements. It is known that the number,
size and position of rock bridges along the potential failure plane are of
prime importance when assessing slope stability. However, the rock bridge failure phenomenology itself has not been comprehensively understood up to
now. In this study, the propagation cascade effect of rock bridge failure
leading to catastrophic block sliding is studied and the influence of rock
bridge position in regard to the rockfall failure mode (shear or tension)
is highlighted. Numerical modelling using the distinct element method
(UDEC, Itasca) is undertaken in order to assess the stability of a 10 m3
rock block lying on an inclined joint with a dip angle of 40 or
80∘. The progressive failure of rock bridges is simulated
assuming a Mohr–Coulomb failure criterion and considering stress transfers
from a failed bridge to the surrounding ones. Two phases of the failure
process are described: (1) a stable propagation of the rock bridge failures
along the joint and (2) an unstable propagation (cascade effect) of rock bridge failures until the block slides down. Additionally, the most
critical position of rock bridges has been identified. It corresponds to the
top of the rock block for a dip angle of 40∘ and to its bottom for
an angle of 80∘.

International audience ; This paper analyses promises made by companies to various publics, including global investors, national public administrative bodies, and local populations. We speak of 'promise engineering' to describe both the integration of the making of promises in mining exploration operations, and the attempted articulation of promises made to different publics with different concerns. We focus on the French 'mining revival', which prompted exploration projects that became controversial, and integrated a government-led approach meant to introduce an objective of 'responsibility' in mining operations. Mining junior companies attempted to make promises that were both technical and social, while responsibility proved consistent with the crucial role of financial investment. We show that promise engineering offers an analytical lens for studying anticipation practices in industrial projects and the opposition these projects face.

International audience ; This paper analyses promises made by companies to various publics, including global investors, national public administrative bodies, and local populations. We speak of 'promise engineering' to describe both the integration of the making of promises in mining exploration operations, and the attempted articulation of promises made to different publics with different concerns. We focus on the French 'mining revival', which prompted exploration projects that became controversial, and integrated a government-led approach meant to introduce an objective of 'responsibility' in mining operations. Mining junior companies attempted to make promises that were both technical and social, while responsibility proved consistent with the crucial role of financial investment. We show that promise engineering offers an analytical lens for studying anticipation practices in industrial projects and the opposition these projects face.

International audience ; This paper analyses promises made by companies to various publics, including global investors, national public administrative bodies, and local populations. We speak of 'promise engineering' to describe both the integration of the making of promises in mining exploration operations, and the attempted articulation of promises made to different publics with different concerns. We focus on the French 'mining revival', which prompted exploration projects that became controversial, and integrated a government-led approach meant to introduce an objective of 'responsibility' in mining operations. Mining junior companies attempted to make promises that were both technical and social, while responsibility proved consistent with the crucial role of financial investment. We show that promise engineering offers an analytical lens for studying anticipation practices in industrial projects and the opposition these projects face.

International audience ; This paper analyses promises made by companies to various publics, including global investors, national public administrative bodies, and local populations. We speak of 'promise engineering' to describe both the integration of the making of promises in mining exploration operations, and the attempted articulation of promises made to different publics with different concerns. We focus on the French 'mining revival', which prompted exploration projects that became controversial, and integrated a government-led approach meant to introduce an objective of 'responsibility' in mining operations. Mining junior companies attempted to make promises that were both technical and social, while responsibility proved consistent with the crucial role of financial investment. We show that promise engineering offers an analytical lens for studying anticipation practices in industrial projects and the opposition these projects face.

International audience ; France has a long history in mining and, to a lesser extent, in hydrocarbon extraction, but these industries were both in decline by the end of the 20 th century. Following the American shale boom in the 2000's, there was a sudden renewal of hydrocarbon exploration in 2010 with new exploration licenses being delivered for unconventional oil and gas projects. These projects first remained confined to specialists of such industries until the end of 2010, when a massive social movement opposed shale gas exploration. This paper aims at drawing a picture of this social movement and its narrative work to obtain the ban on hydraulic fracturing by the French government in 2011. We show that i) public and political perceptions of unconventional gas in general were built mostly during the sudden burst of mobilization in late 2010, with the opponent's narratives encountering almost no resistance, ii) previous knowledge and experience with extractive industries in some areas of France facilitates social license there, but it does not guarantee the development of the industry, iii) the controversy about hydraulic fracturing participated to shape negative perception about extractive industries in France in general, including ore mining.

International audience ; France has a long history in mining and, to a lesser extent, in hydrocarbon extraction, but these industries were both in decline by the end of the 20 th century. Following the American shale boom in the 2000's, there was a sudden renewal of hydrocarbon exploration in 2010 with new exploration licenses being delivered for unconventional oil and gas projects. These projects first remained confined to specialists of such industries until the end of 2010, when a massive social movement opposed shale gas exploration. This paper aims at drawing a picture of this social movement and its narrative work to obtain the ban on hydraulic fracturing by the French government in 2011. We show that i) public and political perceptions of unconventional gas in general were built mostly during the sudden burst of mobilization in late 2010, with the opponent's narratives encountering almost no resistance, ii) previous knowledge and experience with extractive industries in some areas of France facilitates social license there, but it does not guarantee the development of the industry, iii) the controversy about hydraulic fracturing participated to shape negative perception about extractive industries in France in general, including ore mining.

International audience ; France has a long history in mining and, to a lesser extent, in hydrocarbon extraction, but these industries were both in decline by the end of the 20 th century. Following the American shale boom in the 2000's, there was a sudden renewal of hydrocarbon exploration in 2010 with new exploration licenses being delivered for unconventional oil and gas projects. These projects first remained confined to specialists of such industries until the end of 2010, when a massive social movement opposed shale gas exploration. This paper aims at drawing a picture of this social movement and its narrative work to obtain the ban on hydraulic fracturing by the French government in 2011. We show that i) public and political perceptions of unconventional gas in general were built mostly during the sudden burst of mobilization in late 2010, with the opponent's narratives encountering almost no resistance, ii) previous knowledge and experience with extractive industries in some areas of France facilitates social license there, but it does not guarantee the development of the industry, iii) the controversy about hydraulic fracturing participated to shape negative perception about extractive industries in France in general, including ore mining.

International audience ; France has a long history in mining and, to a lesser extent, in hydrocarbon extraction, but these industries were both in decline by the end of the 20 th century. Following the American shale boom in the 2000's, there was a sudden renewal of hydrocarbon exploration in 2010 with new exploration licenses being delivered for unconventional oil and gas projects. These projects first remained confined to specialists of such industries until the end of 2010, when a massive social movement opposed shale gas exploration. This paper aims at drawing a picture of this social movement and its narrative work to obtain the ban on hydraulic fracturing by the French government in 2011. We show that i) public and political perceptions of unconventional gas in general were built mostly during the sudden burst of mobilization in late 2010, with the opponent's narratives encountering almost no resistance, ii) previous knowledge and experience with extractive industries in some areas of France facilitates social license there, but it does not guarantee the development of the industry, iii) the controversy about hydraulic fracturing participated to shape negative perception about extractive industries in France in general, including ore mining.

International audience ; France has a long history in mining and, to a lesser extent, in hydrocarbon extraction, but these industries were both in decline by the end of the 20 th century. Following the American shale boom in the 2000's, there was a sudden renewal of hydrocarbon exploration in 2010 with new exploration licenses being delivered for unconventional oil and gas projects. These projects first remained confined to specialists of such industries until the end of 2010, when a massive social movement opposed shale gas exploration. This paper aims at drawing a picture of this social movement and its narrative work to obtain the ban on hydraulic fracturing by the French government in 2011. We show that i) public and political perceptions of unconventional gas in general were built mostly during the sudden burst of mobilization in late 2010, with the opponent's narratives encountering almost no resistance, ii) previous knowledge and experience with extractive industries in some areas of France facilitates social license there, but it does not guarantee the development of the industry, iii) the controversy about hydraulic fracturing participated to shape negative perception about extractive industries in France in general, including ore mining.

Abstract. To date, many rockfall hazard assessment methods still consider qualitative observations within their analysis. Based on this statement, knowledge and expertise are supposed to be major parameters of rockfall assessment. To test this hypothesis, an experiment was carried out in order to evaluate the influence of knowledge and expertise on rockfall hazard assessment. Three populations were selected, having different levels of expertise: (1) students in geosciences, (2) researchers in geosciences and (3) confirmed experts. These three populations evaluated the rockfall hazard level on the same site, considering two different methods: the Laboratoire des Ponts et Chaussées (LPC) method and a method partly based on the "slope mass rating" (SMR) method. To complement the analysis, the completion of an "a priori" assessment of the rockfall hazard was requested of each population, without using any method. The LPC method is the most widely used method in France for official hazard mapping. It combines two main indicators: the predisposition to instability and the expected magnitude. Reversely, the SMR method was used as an ad hoc quantitative method to investigate the effect of quantification within a method. These procedures were applied on a test site divided into three different sectors. A statistical treatment of the results (descriptive statistical analysis, chi-square independent test and ANOVA) shows that there is a significant influence of the method used on the rockfall hazard assessment, whatever the sector. However, there is a non-significant influence of the level of expertise of the population the sectors 2 and 3. On sector 1, there is a significant influence of the level of expertise, explained by the importance of the temporal probability assessment in the rockfall hazard assessment process. The SMR-based method seems highly sensitive to the "site activity" indicator and exhibits an important dispersion in its results. However, the results are more similar with the LPC qualitative method, even in the case of sector 1.