【摘要】 "5.12"震后,崩塌成为灾区严重的次生灾害类型之一,本文探讨其成灾模型、灾害模拟及危险性评价方法。通过研究,主要取得如下成果:①通过崩塌动力-运动学分析,建立其成灾过程模型,并基于GIS环境开发了崩塌模拟扩展模块RA(RockfallAnalyst),可获取山地复杂地形区崩塌运动路径、频率、速度、能量、跃高等致灾关键信息,实现区域崩塌灾害危险性评价;②将RA应用于"5.12"汶川极震区都-汶公路的崩塌灾害模拟中,利用震后第10天即2008-05-22日2.5m分辨率的SPOT5遥感影像提取了崩塌信息源,采用1∶5万DLG地形图生成DEM及下垫面信息,进而模拟分析汶川地震灾区都汶公路灾后重建中面临的崩塌问题,实现了都汶公路主要危险区段映秀沙坪关-绵篪段崩塌灾害危险性评价;③都汶公路崩塌灾害模拟及评价结果表明,崩塌灾害暴发主要集中于两个区域,一个是沙坪关-彻底关-皂角沱,另一个是羊店村-大坪-飞沙关。崩塌灾害模拟的结果表明映秀至绵篪段的公路崩塌风险集中在连山村至草坡一段,在彻底关和桃关达到最大;其中彻底关于2009年7月29日发生了严重的崩塌灾害,说明模拟方法及结果具有较好的可信度。模拟及评估方法对于崩塌灾害风险管理及控制具有很好的应用推广价值。更多还原

【Abstract】 Rockfall becomes one type of serious secondary disasters after"5.12"Wenchuan earthquake.Risk control technology is an important part for risk management,especially for post-reconstruction.Rockfall study is therefore essential for its hazard mitigation.The Dujiangyan-Wenchuan highway located near the epicenter of the quake was examined.Key problems about rockfall hazard,such as constructing momentum and motion models,simulation,and risk assessment methods were discussed.Almost 210,000 rockfall points were simulated and most of the trajectory path vectors were analyzed.The motion processing model for rockfall simulation was established through dynamics and kinematic analysis.AO-based software of RA(Rock Analyst)which was developed under the ArcGIS9.x platform was built,through which some critical information for rockfall risk assessment,such as trajectory path,frequency,speed,energy,and jump height,can be obtained and simulated for complex mountainous areas.For RA extension,the trajectory path vector is an elementary step for its following statistic analysis,such as frequency and energy jump height,or even for subsequent risk control analysis.It was shown that many trajectory vectors passed through Chediguan Highway Bridge in the simulation.RA was applied to the extremely destroyed area along the reconstruction lifeline of the Dujiangyan-Wenchusan highway in"5.12"Wenchuan earthquake. A SPOT5 satellite image of 2.5 m resolution pixel acquired on May 22,2008 was used for deriving the source information of rockfall distribution.Meanwhile,DEMs of high accuracy derived from 1: 50,000 DLG topographic databases were used to construct the geomorphic surface of slope for simulation.Based on the simulation and field identification,rockfall risk assessment was realized.Results show that areas of the highest risk were primarily concentrated in two places:One was along the segment of Shapingguan-Chediguan-Zhaojiaotuo,and the other was Yangdian-Daping-Feishaguan.The most serious risk took place from Lianshan Village to Caopo Village.The two points of the highest risk were Chediguan and Tiaoguan,which was verified by the serious rockfall hazard occurring on July 29,2009.The simulation and evaluation methods for risk management of rockfall disasters and control provide a rapid and accurate technique for rockfall risk assessment over large areas.更多还原