阻扰公路倒木特征、风险及预砍伐研究OA

In order to scientifically manage and maintain roadside tree,a one-year survey was conducted on the 221.9 km long expressway in Hechi area to investigate spatiotemporal occurrence,tree characteris-tics,lodging types,subgrade types,and obstruction range of traffic-blocking fallen trees.The influence of topography and meteorology was analyzed and the obstruction risk was quantified based on the ratio of tree height to lateral distance.Preventive logging standards were subsequently determined.Research showed that:(1)There were 55 obstruction incidents,with an average of 0.25 incidents per kilometer per year,mainly occurring from April to June with daytime frequency approximately twice that of night-time.Obstruction incidents were concentrated in transition section from karst depressions and plain edges to peak-cluster mountains,with cutting sections exhibiting higher obstruction risk than zero-fill excavation and embankment sections.Main contributing factors include the wind in the horn mouth terrain,soft re-sidual soil,slope aspect,temperature,number of rainy days,and number of strong wind days.(2)The majority of fallen trees resulted from root digging lodging,with an average tree height of 7.41 m,breast height diameter of 10.1 cm,maximum distance from the roadside of 9.5 m,and the average extension into the road of 2.8 m;25%of fallen trees entering the traffic lane.(3)Leucaena glauca,Broussonetia papyrifera and deadwood were identified as high-risk tree species that require special monitoring,while Ailanthus altissima,Bauhinia and Eucalyptus had high H/M ratios,making them advantageous tree spe-cies for balancing ecological landscapes and obstructing risks.