Abstract
The deformation (response) and the rupture limit of steel beams struck by boulders inside a debrisflow are made clear for the design of slit dams using steel pipes, as a measure against debris flows. Static loading tests and impact bending rupture tests on simple beams and cantilevers have been conductedto find out the characteristics of deformation. The measured values can be well explained by applyingthe 2-mass system model. The impact force absorptivity is to be used as a criterion (EDC) for the impactbending rupture. It can be obtained by equating it to the static energy absorptivity, with the followingempirical formulae.
For simple beams, EDC=0. 57Zp2/I+6. 30(tf·cm) For cantilevers, EDC=2. 75 Zp2/I-1. 00(tf·cm) where, EDC is the impact force absorptivity(tf·cm) Zp is the coefficient of plastic section(cm3) and I isthe geometrical moment of inertia(cm4) .
