Rockfalls Movement mode and Movement Features by Field Tests
YE Si qiao,CHEN Hong kai and XU Jiang
DOI:10.11835/j.issn.1674-4764.2011.02.005
Received November 05, 2010,Revised , Accepted , Available online July 01, 2015
Volume ,2011,Pages 18-23
- Abstract
Field test is a better way to find sensitive factors, explore movement law and get movement parameters in rockfall study. To analyze the influence of rockfall shape, size and movement patterns on its movement law, 112 rockfall field tests are implemented. Statistics of horizontal movement distance and velocity under the influence of rockfall shape, size, and rebounce time are conducted. The results show that no matter what shape rockfall is, its movement mode are limited to rolling and bouncing, and there is no apparent sliding section. And about 59% test rockfalls are intercepted by the platform of slope and roadside trench which can be selected as passive mitigation measures. The spherical, square and short cylinder rockfalls have longer horizontal movement distance, bigger faster velocity, and the same movement features. But the rectangular and sheet rockfalls have poor movement capacity, and their movement features are similar to that of the long cylinder rockfall. To sum up, the cylinder assumption for rockfall movement calculation is more realistic. The rockfalls with smaller quality have the worse movement capacity but the greater randomness. When the rockfalls roll mainly, the kinetic energy loss is serious, and both horizontal movement distance and velocity are greater when it bounces mainly. Furthermore, when rockfall collides with the slope surface, its movement parameters and direction will change dramatically.