Rock Fall Rating System for Highway in Mountain Area

In view of the collapse evaluation problem of rock slope along the highway in the mountain area,the Rock Fall Rating System(RFRS) was put forward.Based on the quantitative analysis and qualitative analysis for the six indexes which include topography factor,highway factor,geology factor,climate factor,rock fall history factor and a weighted multiplier of protective measures,both grading basis and grading criteria for RFRS were worked out.As a case study,the rock fall geological hazard susceptibility along Shuifu-Maliuwan expressway in Yunnan Province was evaluated by the RFRS method.At the same time,contrastive analysis with the method of zoning and evaluation for collapse susceptibility was carried out.The result shows that(1) the length of grade B for Fuxing section of Shuifu-Maliuwan expressway is up to 4.3 km,it is suggested that professional staff should be arranged to collect and analysis the related data termly;(2) the RFRS method has many advantages,such as comprehensive factors,convenience operation,scientific grading and practical application.