危岩带稳定性分析与落石轨迹预测——以四川甘孜万岁山为例

Stability of dangerous rockmasses and prediction of rockfall trajectory:A case study at Wansui Mountain in Ganzi County of Sichuan Province

甘孜县甘孜镇万岁山斜坡危岩带多年来时常有落石发生,严重威胁到了下方居民的生命财产安全,因此对万岁山斜坡进行危岩带稳定性分析与落石轨迹预测尤为重要。以万岁山斜坡的危岩带为对象,利用无人机倾斜摄影结合现场调查获取了危岩带几何尺寸和三维形态,分析了危岩带的发育特征和危岩体的分布特征,对危岩稳定性进行了分析;基于RAMMS-ROCKFALL考虑了危岩体的几何形状和三维地形,模拟了危岩体崩塌后可能的落石运动路径。结果表明:(1)斜坡整体性较完整,受风化作用主要失稳模式为坠落式和倾倒式,共发育有7处危岩带,地震工况下为不稳定状态;(2)通过模拟得到了滚落弹跳高度、速度、动能和轨迹、位置的关系,并通过预测落石运动轨迹得到了危岩带的威胁范围、威胁对象,预测结果表明万岁山斜坡对下方居民房屋和街道行人产生的威胁较大,应该尽快采取治理措施。研究成果表明无人机倾斜摄影的利用,有利于斜坡危岩体的稳定性分析,弥补了传统调查的盲区,提高了调查的效率与质量,对危岩体的调查与落石轨迹分析提供了一个新思路,对于减灾技术研究与危岩体的治理有积极意义。

The hazardous rock zone on the Wansui Mountain slope in Ganzi Town,Ganzi County,has experienced frequent rockfalls over the years,posing a serious threat to the lives and property of residents below.Therefore,it is crucial to conduct stability analysis of the hazardous rock zone and rockfall trajectory prediction for the Wansui Mountain slope.Focusing on the dangerous rock zone of Wansui Mountain's slope,the geometric dimensions and 3D morphology of the zone were obtained using drone oblique photography combined with field surveys.The development characteristics of the dangerous rock zone and the distribution characteristics of the dangerous rock bodies were analyzed,and the stability of the dangerous rocks was assessed.Based on RAMMS-ROCKFALL,considering the geometric shapes of the dangerous rocks and the 3D terrain,potential rockfall trajectories after the collapse of the dangerous rocks were simulated.The results show that:The slope is generally intact,with the main instability modes being falling and toppling due to weathering.A total of seven dangerous rock zones have developed,which are in an unstable state under seismic conditions;the simulation provided the relationships between rolling and bouncing heights,speeds,kinetic energy,trajectories,and positions.By predicting the rockfall trajectories,the threat range and targets of the dangerous rock zone were determined.The prediction results indicate a significant threat to the houses and pedestrians on the streets below the slope of Wansui Mountain,and remedial measures should be taken as soon as possible.The research results indicate that the use of drone oblique photography is beneficial for the stability analysis of dangerous rock bodies on slopes,compensating for the blind spots of traditional surveys,and improving the efficiency and quality of the investigation.This provides a new approach for the investigation of dangerous rock bodies and rockfall trajectory analysis,which has positive significance for disaster mitigation technology research and the management of dangerous rock bodies.