The impact force due to huge boulders of the debris flow is very large and can easily cause damages to debris control structures. It is intended to carry out impact tests to evaluate the effectiveness of using wasted-tire cushion device on reducing the maximum impact force. Both impact forces and deflection were recorded by using an iron ball striking wasted-tire cushion device.

In this study, two experiments, scour experiment and sedimentation experiment, are utilized on the U-turn horizontal section of fish way to examine causes which lead to sedimentation situation. Through scour experiment, the silt clearance capacity of clear-water discharge revealed on U-turn horizontal section of fish way is explored. On the other hand, while proceeding sedimentation experiment some elements are setting T-bone structure, etc. Adding sand following by a period time, we inspect how sand particle affects sedimentation furthering to see whether fish way is blocked accordingly.

There is a repeated phenomenon of the screen device. How much gravel can be block that will according to the gauage of infiltration spacing, hence the clear spacing of the bars of the screen, the infiltration angle of ingiltration screen, the length of the bar of the screen are all important factors.