隧道洞口坡段落石灾害危险性等级评价方法

The Evaluation Method for the Hazard Grading of the Rockfall at the Slope Segment of the Tunnel Entrance

出于隧道洞口坡段落石灾害防治决策的需要,针对铁路和公路的隧道洞口及交通运营特点,从落石致灾可能性(包括危岩崩落可能性、落石达到洞口区域可能性)和致灾严重性2个方面对落石灾害危险性等级进行综合评价,据此定义隧道洞口坡段落石灾害危险性分级指标,并在量化评分各影响因子的基础上,建立隧道洞口区域落石灾害危险性等级评价方法。将该方法用于8个隧道洞口的落石灾害危险性评价,结果表明该方法能够满足落石防治决策需要,并可为落石运动路径、速度、动能等计算设定风险等级。

To meet the need of the decision-making for the rockfall control at the slope segment of the tunnel entrance,and in connection with the features of the tunnel entrance as well as the traffic operation of both the railway and the highway,the hazard grading for the rockfall was comprehensively evaluated.The evaluation was conducted from two aspects,namely,the possibility of rockfall causing hazard（including the possibility of the dangerous rock collapsing and the possibility of the rockfall reaching the tunnel entrance） and the severity of the hazard.Accordingly,the grading indexes for the rockfall hazard at the slope segment of the tunnel entrance were defined.On the basis of quantitatively scoring each influencing factor,the evaluation method was established for rockfall hazard grading in the zone of the tunnel entrance.The method was applied to the rockfall hazard evaluation of eight tunnel entrances.The results show that the method can meet the needs of the decision-making for the rockfall control and can set the risk grade for the calculation of rockfall movement path,speed,kinetic energy and so on.