某铁路隧道口危岩落石的综合勘察和分析评价OA

In order to explore the application effectiveness of comprehensive investigation techniques and assessment methods for dangerous rockfalls,this study focuses on a dangerous rockfall site at a high-speed railway tunnel portal in Southern China.Based on comprehensive investigation methods,including UAV oblique photography,airborne LiDAR,and manual field survey,a 3D real-scene model,a hillshade model,and a survey statistical model were established to obtain detailed data on the distribution extent,scale,morphology,and discontinuity characteristics of dangerous rockfalls.On this basis,a semi-quantitative method was used to assess the site risk,and the stereographic projection method,along with stability calculation,were applied to determine whether instability failure would occur and to identify failure modes.Subsequently,preliminary trajectory analysis was conducted to exclude some non-hazardous rockfalls.Finally,numerical simulations were performed for the remaining rockfalls to simulate and predict motion trajectories,velocities,and energies,thereby assessing their hazards and proposing corresponding engineering measures and recommendations.Results showed that the three investigation methods each had advantages in specific application scenarios,and a comprehensive investigation approach could complement these advantages and reduce omissions in dangerous rockfall surveys.At this site,the probability level of dangerous rockfall collapse was 5,the consequence level was 4,and the risk level was extremely high.Dangerous rock W1 was dominated by toppling failure,whereas W2 did not undergo instability failure.Two rockfalls were predicted to encroach on the site and cause hazards,mainly through rolling and sliding,with a maximum horizontal runout distance of 82.31 m,a maximum impact energy of 0.39 kJ,and a maximum bounce height of 0.09 m.It is recommended to remove the dangerous rockfalls at locations L5 and L7 to ensure engineering safety.