. Rockfall is an extremely rapid process involving long travel distances. Due to these features, when an event occurs, the ability to take evasive action is practically zero and, thus, the risk of injury or loss of life is high. Damage to buildings and infrastructure is quite likely. In many cases, therefore, suitable protection measures are necessary. This contribution provides an overview of previous and current research on the main topics related to rockfall. It covers the onset of rockfall and runout modelling approaches, as well as hazard zoning and protection measures. It is the aim of this article to provide an in-depth knowledge base for researchers and practitioners involved in projects dealing with the rockfall protection of infrastructures, who may work in the fields of civil or environmental engineering, risk and safety, the earth and natural sciences.

/pdf/rockfall-characterisation-and-structural-protection-a-review-3blfxd9i44.pdf

Rockfall characterisation and structural protection – a review

Rock restraining net is a device engineered to stop large rockfalls. The system consists of a net vertically supported by steel posts with “energy dissipators” able to dissipate high kinetic energy by large displacements. These fences have been usually placed to protect against rockfalls in mountainous areas but few tests have been developed correctly to define the behaviour of these structures. In this paper full scale tests on passive defence against rock falls are presented. The tests have been carried out in a field test site especially designed and built. The test site has been provided of camera apparatus able to monitor the impact of the block against the fence. The impact energy and the consequent forces and displacements of the fence are studied. The tests have been carried out on many different fence types and have allowed the definition of a well-established design procedure.

Evaluation of Behaviour of Rockfall Restraining Nets by Full Scale Tests

Experimental studies on fragmentation of rock falls on impact with rock surfaces

Impact of rocks onto gravel Design and evaluation of experiments

More than 6% of Switzerland is prone to slope instability. New federal regulations require regional authorities (cantons) to generate natural hazard maps and the zoning of mass movements to restrict development on hazard-prone land. The paper discusses the proposed three-step procedure of hazard identification, hazard assessment and risk management. The Codes of Practice concerning the hazard maps involve the standard use of three col- ours (red, blue and yellow) to indicate areas of prohibited construction, construction with certain safety requirements and construction without re- striction. ResumePlus de 6% du territoire suisse est soumis a des phenomenes d'instabilites de terrain. De nouv- elles bases legales exigent des autoritesr egionales l'etablissement de cartes de danger et le zonage pour les mouvements de terrain afin de restreindre le developpement dans les zones sensibles. Une pro- cedure en trois etapes comprend l'identification du danger, l'evaluation du danger et la gestion du ris- que. L'application dans l'amenagement de ces cartes de danger peut etre resumee ainsi: dans les zones rouges les constructions sont interdites, dans les zones bleues les constructions sont autorisees lors- que des prescriptions techniques de securitesont respectees et dans les zones jaunes les constructions sont autorisees.

Hazard assessment in Switzerland - Codes of Practice for mass

Note: Roches Reference LMR-ARTICLE-1996-001 Record created on 2006-11-09, modified on 2016-08-08

Experimental study of rock sheds impacted by rock blocks

Le dimensionnement des galeries de protection contre les chutes de pierres depend fortement de l'estimation des sollicitations dynamiques, que l'utilisation d'une couche amortissante peut reduire considerablement. Afin d'approfondir les connaissances actuelles sur les capacites d'amortissement des materiaux meubles, une etude experimentale a ete menee au Laboratoire de Mecanique des Roches de l'EPFL : des blocs de 100, 500 et 1000 kg ont ete laches de diverses hauteurs (inferieures ou egales a 10 m) sur une dalle en beton arme recouverte par un remblai d'epaisseur variable constitue de trois types de materiaux differents. Les dispositifs et programme d'essais sont tout d'abord presentes. Ensuite, un exemple complet permet d'illustrer les divers enregistrements effectues lors d'un impact, ainsi que les traitements posterieurs a celui-ci. Finalement, une analyse des resultats experimentaux souligne les principales tendances entre les grandeurs mesurees et debouche sur l'elaboration d'expressions mathematiques entre certaines de ces variables. (A). (Titre en anglais : Experimental study of rock blocks falling down on a reinforced concrete slab covered by absorbing cushions).

/pdf/etude-experimentale-de-la-chute-de-blocs-rocheux-sur-une-5d9pwnrj36.pdf

Etude expérimentale de la chute de blocs rocheux sur une dalle en béton armé recouverte par des matériaux amortissants

Among the different natural hazards, rockfall has an important place even though other natural hazards could affect more people or have greater consequences. The phenomenon may be further classified according to the size of the largest blocks and the total rock mass involved. The risk management procedure can be divided into (a) hazard identification and description, (b) hazard assessment and (c) risk management and treatment. Initiation zones of rockfall are identified and characterized by using geodetic, geomorphic, geotechnical and historical data. Trajectories are analyzed and boulder impacts are modelled to identify endangered areas. A variety of methods exist to estimate the frequency of rockfall events. Finally, hazard maps are produced that indicate the hazard level based on the intensity and probability of rockfall events. Together with indications on the occupancy and vulnerability of buildings and infrastructure, risks can be calculated and compared with acceptable values for new projects and tolerable ones for existing assets. The most effective countermeasure is land-use planning to avoid dangerous areas. If this is not possible or existing assets have to be protected, geotechnical and structural mitigation measures are justified. They cover measures in the initiation zone, along the propagation path and in the deposit zone. The types of structure used are flexible barriers, galleries, embankments and dams, depending on the position of the protective measure and the available space, the energy to be absorbed and other functions the structures should fulfill. Structures are dimensioned to withstand the impact of a design block, taking into account the damping effect of a possible cushion layer and the dynamic response of the structure itself.

Rockfall protection as an integral task.

Keywords: Chute de blocs ; Dimensionnement ; Charges d'impact Reference Record created on 2004-09-07, modified on 2016-08-08

Vincent Labiouse

Papers

Experimental study of rock sheds impacted by rock blocks

Etude expérimentale de la chute de blocs rocheux sur une dalle en béton armé recouverte par des matériaux amortissants

Rockfall protection as an integral task.

Impact Load by Roch Falls and Design of Protection Structures, joint Japan Swiss scientific seminar, Kanazawa, Japan