Stress distribution of rockfall events on galleries

摘要

Rockfall galleries are built to protect local infrastructure and lifelines against rockfall events. They are covered usually with a soil layer, sometimes for aesthetical reasons but also for protection against impact from rockfalls and snow avalanches. The effect of the impact has been quantified in a research project by investigating the properties of the cover (cushion) material. The stress distribution caused by a rockfall event is measured in centrifuge model tests by means of a tactile multipoint pressure transducer on the gallery below the cushion material as well as point load measurements at supports and strain gauges to determine bending of the gallery slab. The technique of measuring stress distribution under a soil layer is adapted from bio-medicine and the car industry to soil mechanics. Features of these pressure sensors will be discussed in relation to the response to a rockfall event and for different types and thicknesses of cushion material. Numerical modelling has also been carried out using LS DYNA. Knowledge gained can be used for formulation of guidelines for the gallery design.