Keynote speakers

Pierre Azémard, Engineer geologist,
Cerema, France

The RN1 in Reunion Island : Rock Hazard Management :
circulation management, protections works and new route

Tom Badger, Chief Engineering Geologist
at Washington State Department, USA

Perceptions of risk in response to geologic hazards

Engineer geologist from ENSG (1986) my professional career begins with a stay of 3.5 years on the island of La Réunion where I am successively in charge of water research studies and landslides risks (BRGM) then flood hydrology (DDE974). From 1990, I work at regional laboratory of Aix en Provence at the CETE Mediterranée (now Cerema Méditerranée) in charge of infrastructure projects reconnaissance (A75, TGV Med, Tamarins Route) in south of France ; mainly specialized on rock massifs. Gradually from 1994 my activity turns towards landslides risks (hazards and protection) and more particularly the rockfalls which constitute now the essence of my work.

The RN1 in Reunion Island : Rock Hazard Management : circulation management, protections works and new route

Since the creation of the route at the foot of the cliff in the 60s the “route en corniche” is subject to frequent falls of blocks that have made more than a dozen victims. The conference will present the actions carried out over the last twenty years in order to improve the safety of the route : management regarding rainfall, setting up deflector nets, new bridge and dam away from the cliff.

Tom Badger received a BS in geology in 1983 and an MS in geological engineering in 2002. He worked for the Washington State Department of Transportation for 32 years, the last five serving as Chief Engineering Geologist, before retiring in 2016. In this role, he was responsible for managing design, construction and maintenance aspects pertaining to soil and rock engineering, blasting, and rockfall and landslide hazards. He has authored numerous publications on these topics, and presently consults on geologic hazards and risk management for transportation infrastructure.

Perceptions of risk in response to geologic hazards

An effective management response to a specific geologic hazard relies upon a well-founded characterization of the problem, understanding potential consequences and imminence of occurrence, as well as the identification of uncertainties. When managing response for many hazards, a means is also needed to prioritize resources. Management response is guided by perceptions of risk. Examples of risk perception and response to geohazards by owners and the public will be presented, highlighting the important responsibilities of the geohazard specialist.

Dr Anna Giacomini, Associate Professor at
University of Newcastle, Australia

Rockfall in mining:
mitigation measures design and hazard assessment

Dr. Fabien Hobléa, geomorphologist member of
the laboratory EDYTEM, france

Between risk and geoheritage:
the Mont Granier collapse of 1248 and its recent sequels.

Associate Professor Giacomini is committed to the deployment of innovative procedures to promote and improve safety in civil and mining environments. She received her PhD in 2003 from the University of Parma, Italy, and joined the University of Newcastle in 2005. She is currently Associate Professor in the Priority Research Centre of Geotechnical Science in Engineering and Higher Degree Research Director for the School of Engineering in the Faculty of Engineering and Built Environment of the University of Newcastle, Australia.
Associate Professor Giacomini has worked in the area of Rock Mechanics for more than 15 years. Adapting to the new Australian Environment, she has extended her rich background and extensive research experience in rockfall analysis and rock mechanics from civil engineering to mining. She is leading six major research projects through the Australian Coal Association Research Program (ACARP) on rockfall hazard and mitigation. Associate Professor Giacomini was the principal researcher of an Australian Research Council Linkage Project devoted to developing new designs for engineered barriers to protect valuable infrastructure, such as roads and railways, from rock fall hazards, and she is currently leading a recently funded Australian Research Council Linkage Project for the development of new innovating monitoring methodologies of rock slopes.

Rockfall in mining: mitigation measures design and hazard assessment

Rockfall risk is most of the time considered and managed in the context civil infrastructure, such as road or railway corridors. Rockfall is less frequently analysed in the context of mining environments, yet it threatens human lives, machinery and portal structures for underground entry located at the toe of highwalls. Safety of workers in all mine areas affected by rockfall has to be rigorously managed and appropriate mitigation measures become necessary to reduce the risk to an acceptable level. In addition, rockfall hazard can have significant financial consequences as it stops production until the pit is again deemed to be safe. Millions of dollars are lost annually due to rockfall.
This presentation will focus on rockfall hazards and its impact in surface mining. In particular, recent innovative techniques for the investigation of the efficiency of rockfall protection measures will be presented and the development of a rigorous guidance on rockfall management strategies will be discussed. The research was developed in an Australian context but is applicable to a broader international context, both in civil and mining environments.

Dr. Fabien Hobléa is senior lecturer and geomorphologist member of the laboratory EDYTEM (Environments, Dynamics and Territories of Mountain areas) at University Savoie Mont Blanc (Chambéry, France). He is involved in several scientific councils of mountain protected areas and Geoparks; he is also co-chairman of the Working Group on Geomorphosites of the International Association od Geomorphologists. He works on calcareous and karstic mountains, aiming to study the interactions between the different dynamics shaping these type of mountains, especially karst processes and mass movements. This approach has been developped since his PhD defended in 1999, based on the case study of the Mont Granier in the French subalpine massif of Chartreuse, nearby Chambéry.

Between risk and geoheritage: the Mont Granier collapse of 1248 and its recent sequels.

In November 1248 occured at Mont Granier (Chartreuse massif, France) and its surroundings the biggest historical disaster due to a geohazard in the Alps. The collapse of the north face and the consecutive landslide of 500 hm^3 caused more than 1000 deaths and totally destroyed what was at the time the most important city in Savoy. This lecture will present the actual state of the art of the multidisciplinary knowledge on this major event. The consecutive and always active unstability of the Mont Granier will also be analyzed. The current studies made by several research institutes in a collaborative approach with the High Chartreuse nature reserve will be introduced. The lecture will also show how the case of the Mont Granier allows to link risk and geoheritage, in order to manage both in a holistic and integrated approach.

Michel Jaboyedoff, Geologist,
University of Lausanne, Switzerland

About the “rockfall” failure hazard assessment

Michel Jaboyedoff is a geologist and has a degree in physics and a PhD degree in clay mineralogy. During his PhD, he started doing research on natural hazards, especially on rockfall. In 2017, he received the DPRI Award. Since 2005, he is a full professor at the University of Lausanne, focusing his research on natural hazards and related risks. He is working on integrated risk analysis and he is involved in several risk management projects around the world (Argentina, Canada, Nepal, Norway, Switzerland …), and is part of several European Projects FP7 (Mountain Risks, Safeland, CHANGES) and Swiss National Science Foundation. Many studies are related to remote sensing technique such as Lidar. One of his focuses is the development of software for hazard and risk analysis. Especially about rockfall hazard rating. He also the president of the Quanterra foundation and co-founder of a spin-off of the University of Lausanne (terr@num).

Usually rockfall hazard assessment is mainly based on rockfall modelling statistics, and on inventories of observed fallen blocks. Only few studies include source hazards assessment by varying the failure frequency depending on the source areas. Such assessment is mainly performed when large volumes can fall (Hantz et al., 2003), but it is not dedicated to zones with diffuse hazard. The rockfall hazard has two components, the frequency of failure and the probability of propagation.

Some approaches mixed the evaluation of both terms, including risks such as Rockfall Hazard Rating System (RHRS) (Pierson, 1990). Here we deal with the assessment of . An approach is to use a susceptibility scale and to calibrate it to reach a frequency, when a rockfall inventory is available. The parameters that control the stability can be subdivided in two groups: the internal characteristics which are the rock type, the structures, permeability, friction angle, cohesion, etc. and that are evolving under the action of external factors such as, temperature, rain, ice, groundwater, earthquakes, etc.