雷电灾害已成为威胁高速铁路运行安全的重要因素,建立科学、系统、规范的高铁牵引网雷电风险评估系统,合理有效地指导高铁牵引网的防雷设计、运行和改造,具有十分重要的必要性和紧迫性。为此基于风险管理的概念提出了高速铁路牵引网雷...雷电灾害已成为威胁高速铁路运行安全的重要因素,建立科学、系统、规范的高铁牵引网雷电风险评估系统,合理有效地指导高铁牵引网的防雷设计、运行和改造,具有十分重要的必要性和紧迫性。为此基于风险管理的概念提出了高速铁路牵引网雷电风险评估方法,讨论了牵引网雷击损害风险源获取方法、牵引网雷击损害类型,提出了不同落点、不同雷电流雷击损害概率的计算方法和流程。提出采用雷击跳闸率作为表征雷害风险的指标,其数值等于风险源数量与雷击损害概率的乘积。通过设定风险评估等级划分标准,实现了雷害风险等级评估,并建立了全参数、全路段雷害风险量化评估流程。京沪高铁评估结果表明:2005—2013年沿线风险源特征具有明显差异性,各段地闪密度最大值约为最小值的6倍,从北往南雷电流幅值累积概率50%电流值从36.5 k A逐渐减小为22.1 k A;2005—2013年京沪高铁全线126网格段中A、B、C、D风险等级的网格段数量分别为24、38、45、19,20%网格段处在低雷害风险,15%网格段处在强雷害风险。所提出的方法可有效确定牵引网雷害风险水平和风险等级分布,发现雷害风险严重区段,为高速铁路牵引网防雷优化设计和运维检修管理提供更加科学准确的参考依据。展开更多
Debris flows are among the most common geological disasters in China,and have been particularly frequent in Sichuan Province since the Wenchuan earthquake on 12 May 2008.The construction of debris flow drainage channe...Debris flows are among the most common geological disasters in China,and have been particularly frequent in Sichuan Province since the Wenchuan earthquake on 12 May 2008.The construction of debris flow drainage channels is a countermeasure used to distribute debris flow fans,and these channels play a critical role in the mitigation and prevention of damage resulting from debris flows.Under field conditions,the useful life of drainage channels can be greatly shortened as a result of strong abrasions to the drainage structure caused by the debris flow.Field investigations have shown that the types of damage to drainage channels include(a) erosion caused by hyper-concentrated silt flow,(b) impact fractures and foundation scour at the groundsills of the drainage channel,(c) destruction of the drainage channel outlet,and(d) destruction of the drainage channel caused by debris flow abrasion.In addition,based on the destruction of the drainage channel during the debris flow drainage process,a new type of drainage channel with energy dissipation components was proposed and applied in a steep,narrow gully for debris flow mitigation.Moreover,design and engineering repair recommendations for drainage channels are provided as a reference for repairing the damage to the channel.The results can provide an important reference for the effective repair and optimal design of drainage channels.展开更多
文摘雷电灾害已成为威胁高速铁路运行安全的重要因素,建立科学、系统、规范的高铁牵引网雷电风险评估系统,合理有效地指导高铁牵引网的防雷设计、运行和改造,具有十分重要的必要性和紧迫性。为此基于风险管理的概念提出了高速铁路牵引网雷电风险评估方法,讨论了牵引网雷击损害风险源获取方法、牵引网雷击损害类型,提出了不同落点、不同雷电流雷击损害概率的计算方法和流程。提出采用雷击跳闸率作为表征雷害风险的指标,其数值等于风险源数量与雷击损害概率的乘积。通过设定风险评估等级划分标准,实现了雷害风险等级评估,并建立了全参数、全路段雷害风险量化评估流程。京沪高铁评估结果表明:2005—2013年沿线风险源特征具有明显差异性,各段地闪密度最大值约为最小值的6倍,从北往南雷电流幅值累积概率50%电流值从36.5 k A逐渐减小为22.1 k A;2005—2013年京沪高铁全线126网格段中A、B、C、D风险等级的网格段数量分别为24、38、45、19,20%网格段处在低雷害风险,15%网格段处在强雷害风险。所提出的方法可有效确定牵引网雷害风险水平和风险等级分布,发现雷害风险严重区段,为高速铁路牵引网防雷优化设计和运维检修管理提供更加科学准确的参考依据。
基金sponsored by the Key Deployment Project of the Chinese Academy of Sciences (KZZD-EW-05-01)the Natural Science Foundation of China (Grant No. 41302283)+1 种基金the Young Scientists Research Fund of the Institute of Mountain Hazards and Environment, CAS (SDSQN-1305)the Young Science Foundation of Key Laboratory of Mountain Hazards and Earth Surface Processes, CAS
文摘Debris flows are among the most common geological disasters in China,and have been particularly frequent in Sichuan Province since the Wenchuan earthquake on 12 May 2008.The construction of debris flow drainage channels is a countermeasure used to distribute debris flow fans,and these channels play a critical role in the mitigation and prevention of damage resulting from debris flows.Under field conditions,the useful life of drainage channels can be greatly shortened as a result of strong abrasions to the drainage structure caused by the debris flow.Field investigations have shown that the types of damage to drainage channels include(a) erosion caused by hyper-concentrated silt flow,(b) impact fractures and foundation scour at the groundsills of the drainage channel,(c) destruction of the drainage channel outlet,and(d) destruction of the drainage channel caused by debris flow abrasion.In addition,based on the destruction of the drainage channel during the debris flow drainage process,a new type of drainage channel with energy dissipation components was proposed and applied in a steep,narrow gully for debris flow mitigation.Moreover,design and engineering repair recommendations for drainage channels are provided as a reference for repairing the damage to the channel.The results can provide an important reference for the effective repair and optimal design of drainage channels.
