| In japan，There are lots of rock-sheds to protect roads and vehicles from falling rocks which are constructed near cliffs in mountainous and/or coastal areas．Most of the rock-sheds are Reninforced Concrete（RC）and/or Prestressed Concrete（PC）structures．Two types of PC rock-sheds are mostly constructed which are inverse L-shape（2-hinge supported and 1-rigidly connected structure）and frame type（3-rigidly supported/connected structure）．In this paper，impact failure tests of large scale frame type of PC rock-shed are conducted by means of iterative and single loading by steel weight falling method．[*]Five PC rock-shed frames are used to investigate the effects of loading point and loading methed on the time history of gending moment distribution and crack pattern/failuer mode．The results obteined from this study are as follows；1）The mid-spen loding is predominant for the bending failure of roof girder；2）Impact failure of PC rock-shed is severely influenced due to iterative loading because of input energy by weight falling being accumulated；3）It is made clear that PC rock-shed model used here has five times safety margin with reference to input falling rock energy for design． |
