Abstract Rockfall protection systems are subject to impact loads, so high standards are required for the design of their foundations. While guidelines exist for support structures, nets, and connecting components, standardized rules for foundation design are lacking. This study presents an experimental investigation on the performance and durability of post foundations under both Service Energy Level (SEL) and Maximum Energy Level (MEL) impact loading. The investigation is based on real-scale, 1:1 tests conducted between 2020 and 2023. Over 175 tests were carried out, including static pile load tests to determine skin friction and impact tests on individual micropiles. Different foundation types and micropile configurations (solid and hollow bars) were evaluated, with a focus on pipe reinforcement, grout cover, and foundation dimensions. Results show that the combination of concrete foundations and pipe reinforcement at compression and tension piles significantly reduces deformations and prevents damage under MEL loading. In contrast, conventional designs showed deficiencies in the concrete foundations and inadequate grout coverage of the micropiles. These findings provide an experimental basis for standardized design rules and informed the development of the Austrian guidelines RVS 08.22.02 and ÖNORM B 4802, offering reliable criteria for the design, construction, and durability of rockfall protection foundations.
Hofmann et al. (Thu,) studied this question.