| Summary: | 碩士 === 中原大學 === 土木工程研究所 === 90 === Taiwan is a mountainous island of frequent rainfalls and earthquakes, and particularly after the 921 Chi-Chi Earthquake, numerous disturbed rock slopes of high potential of landslides have been left along many hillside roads. Among various modes of landslides, rockfall is a great threat to any structure on its moving path. In order to select the most adequate measure, it requires precisely predicting the movement paths of in-situ falling rocks. However, because of inheritable variability of slope profile, contact property between falling rocks and slope, and rock initial state, the modified ROCKPATH code is used to simulate the motion of a falling rock.
In this thesis, the above code which is based on the particle mode and with the capability of Monte Carlo simulation is the main research tool. It can simulate the single and multiple movement paths of a single falling rock. The previous version only dealt with the randomness of contact property, excluding that of surface roughness on the rock surface, which really exists due to measurement error and time variation. The modified code includes this feature to more suitably match the site condition.
In the sensitivity study of a rock bouncing on a straight slope, the influences of restitution coefficients (en, et), roughness angle i and slope angle β on its movement path were investigated. Besides, for a straight slope with a bench, the influences of restitution coefficients (en, et), roughness angle i and bench width W were examined. The analysis results of both sensitivity studies indicated that: 1) with a larger value of en, design height of a rock-trap wall h95 increases; 2) h95 also increases with β. On the other hand, the results of two case studies showed that the Monte Carlo simulations would take into account the effects of rock shape and measurement error in determining slope profile.
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