Research On Identification Technology Of Highway Flood Damage

This dissertation is supported by Application Research On Disaster Prevention AndMitigation In Highway Engineering, the foundation of project of transportation constructionin West China from Ministry of Transport of the People’s Republic of China. Combining withthe arterial highway disaster prevention pilot project, this dissertation mainly researches onthe risk identification technology for highway flood damage, which is caused by heavy rainsor floods. Hazard identification is to have a basic understanding of the activity level, damagecapacity and other characteristics of disaster risk sources. It is the basis for highway disasterprevention and mitigation. Therefore, the highway flood damage identification technology,from the aspects of disaster types, risk factors and degree of risk, has important engineeringsignificance for natural disaster prevention and treatment, as well as the construction,conservation and management of highway.As for the highway engineering, through on-site investigations, theoretical analysis,using the existing indoor model test data, based on the study of the types, causes,identification principles and methods for highway flood damage, the idea of highway flooddamage identification from3levels such as the regional road network, the road line and theroad section, is proposed. And the identification index system is established.The research mainly obtains the following results:(1) Firstly, the highway flood damage is classified into two categories as: highwayflood disaster along rivers (including ravine debris flow, small bridges and culverts washout,highway along river and its erosion protection structures damaged by flood), and sloperainfall disaster (mainly including slope erosion, slope instability induced by rainfall as wellas drainage system and slope protection works damaged by runoff). Then, the types, causesand factors for highway flood disaster along river and slope rainfall disaster, are described.(2) As for the actual situation of highway engineering, Surface Morphology Index Map,The Distribution Map of Highway Rock Types in China and The Distribution Map of HighwaySoil Types in China, which consider such factors as surface slope, altitude, the extent ofsurface fragmentation, as well as the rock and soil types, are compiled by using ArcGIS9.2, toreflect the regional distribution state and its impact on highway construction, and to be helpfulfor the preliminary identification of highway flood damage for regional road network.(3) Risk identification is the basis of risk management. The necessity of identification isdiscussed from the perspective of regional network, road line and road section. The principles,related methods and procedures and technical means of disaster perception are put forward. And the theory basis of identifying flood damage contains: learning from the natural divisionresearch, regional identification theory is proposed in order to grasp the regional distributionof flood damage from a macro point of view; the subgrade disaster analysis method based onsubgrade geotechnical structure, which consists of3elements such as the subgrade geometry,the internal structural planes and the geotechnical engineering properties, is presented, inorder to study disaster features from the perspective of the road lines and road sections.(4) As for highway flood damage along rivers, first, according to streamflow intensityindex,“Region Identification Map of Highway Flood Damage along Rivers in China” iscompiled based on GIS, achieving the preliminary identification of highway flood damagealong rivers for regional road network; second, pre-disaster identification criteria for sectionsprone of flood damage like highway subgrade washout along rivers, small bridges andculverts flooding and ravine debris flow are proposed, besides the road hazard segmentationmethod, which realizes the road line pre-disaster identification of highway flood disaster;third, the hazard calculation method for road sections achieves the precise identification offlood disasters.(5) For the slope rainfall disaster, first, according to slope runoff intensity index,“Region Identification Map of Highway Slope Rainfall Disaster in China” is compiled basedon GIS, realizing the preliminary identification of slope rainfall disaster for regional roadnetwork; second, pre-disaster identification criteria for sections prone of slope rainfall damageare proposed, which provides information for the road line pre-disaster identification ofhighway slope rainfall disaster; third, the highway slope chain reaction mechanism of disasterdevelopment is studied, dividing the development stage of collapse, landslide and slope debrisflow into3stages like early phase, mid-term and late period, on which highway slope rainfallhazard quantitative identification method is suggested, enabling the precise identification ofroad sections slope rainfall disaster.The pre-disaster identification method of flood disasters proposed in this dissertation issimple and practical; and the identification software system developed makes the highwayflood damage identification programmed and visual, both with good maneuverability andeconomy, and undergoing engineering application and validation.