公路沿线遭遇滚石的风险分析——方法研究

RISK ANALYSIS OF ENCOUNTERING ROCKFALLS ON HIGHWAY AND METHOD STUDY

随着中国经济建设的迅速发展,山区内大量公路将面临着越来越多的滚石问题。显然,公路沿线遭遇滚石的风险分析对滚石灾害的分区与防治资金的优化配置是十分重要的。在工程地质力学综合集成方法论(EGMS)的指导下,由现场调查、专家经验、理论分析等结合得到了困难条件下滚石发生频率的估计方法。假定一个滚石区范围内的人类活动和潜在滚石在时间和空间上为均匀分布,利用贝努力公式给出了静止车辆、移动车辆、行人等情况下遭遇滚石的概率计算方法。由遭遇滚石的概率及承灾体的易损性分析,可进一步得到公路上车辆和行人经过不同滚石区时受滚石冲击而致命的风险水平。

As the rapid development of economy in China, a great number of highways in mountainous areas will confront with more and more rockfall problems. Obviously, risk analysis of encountering rockfalls along these traffic routes is of extreme importance for zoning of rockfall hazards and optimum scheme of mitigation costs. Based on the EGMS methodology, a comprehensive way is developed to estimate frequency of tockfalls occurred in difficult mountainous conditions by combining all the information from site investigation, experiences and theoretical analysis. It is supposed that human activities and potential rockfalls in a rockfall zone are uniformly distributed, and some formulas are obtained from Bernoulli formula to compute probability of encountering rockfalls under three situations, i.e., immobile vehicles, mobile vehicles and foot passengers. Thus, risk levels of passing different rockfall zones can be successfully achieved from further vulnerability analysis and the annually averaged probability of encountering rockfalls.