From a constitutive modelling of metallic rings to the design of rockfall restraining nets

Abstract

SUMMARYThis paper considers recent contributions concerning metallic structures designed to stop rockfalls. These structures are composed of metallic nets generally made with anti-submarine rings. Both the singular technology and the spatial array of the rings confer outstanding mechanical properties to the net sheets, which are used today in order to control rockfall trajectories. A spatial description of the net is proposed, and a constitutive modelling in "nite strains is presented. The proposed modelling is based on both the experimental and analytical approaches. But the main feature of this modelling is that the local behaviour of the net can be described in the usual framework of elasto-plasticity. Mechanical analysis of each material body has been carried out, but the complexity of the resulting system imposed the building of a numerical scheme. Finally, this research has led to the development of original computational software, for both industrial and academic purposes. In order to give a clear indication of the capacity of both the modelling and the computational software, a typical example of a simulation is proposed and discussed.

Modelling a geo-composite cell using discrete analysis

“…It seems that this approximation is reasonable for the range of impact velocities found with rockfalls. Previous research shows that rate-independent constitutive models used to describe the behaviour of metallic rings of rockfall restraining nets can reproduce the response of the structure fairly well [32]. The following developments present the constitutive model, then analyse the relevance of this spatial description.…”

“…Over the last few years, a great deal of research has been conducted on the mechanical behaviour of rockfall restraining nets. Experimental approaches based on full-scale tests [44,37] as well as computational investigations [18,19,31,32] have provided valuable new elements leading to a more effective design of these structures. However, the design of reinforced dams generally rests on an empirical approach.…”

Toward objective rockfall trajectory simulation using a stochastic impact model

“…This study focuses on single falling rocks with a volume up to 1.3 m 3 . In rockfall hazard assessment, trajectory simulation models are increasingly used for designing protective measures such as nets and dams (Descoeudres, 1997;Peila et al, 1998;Nicot et al, 2001Nicot et al, , 2007 or for making hazard maps (Kobayashi et al, 1990;Evans and Hungr, 1993;Guzzetti et al, 2002;Chau et al, 2004;Jaboyedoff et al, 2005;Bourrier, 2008;Frattini et al, 2008).…”

Ground reinforced embankments for rockfall protection: design and evaluation of full scale tests

“…This steel mesh is able to intercept the moving block and to transmit the stopping forces to anchors in the ground. Many studies of these structures have been developed in recent years with full-scale tests and numerical dynamic modelling (Smith and Duffy 1990;Peila et al 1998Peila et al , 2006Gerber 1999;Nicot et al 2001;Cazzani et al 2002).…”