| In this study、 in order to investigate impact resistant behavior of rockfall protection galleries、 two 2/5 scale gallery models were made、 and consecutive falling-weight impact tests with/without sand cushion were conducted up to the ultimate state. From these experiments、 the following results were obtained: 1) in case without sand cushion、 roof slab is finally collapsed in punching shear failure mode; 2) in case with sand cushion、 impact force can be estimated using a design formula with Lame’s constant = 1、000 kN/m2 which is derived on the basis of Hertz’s contact theory; 3) the roof slab with sand cushion has not reached the serviceability limit state until input energy Ek = 500 kJ and is under near the ultimate limit state with punching shear failure at Ek = 1、000 kJ. |
