Study Of Hazard Assessment And Prevention Measures For Highway Subgrade Washout By Flood Along Rivers

With the rapid development of highway construction,the unimpeded highway has already become one of the preconditions that influence regional economic development and the improvment of people's living standard.However,the highway washout by flood caused by the heavy rainfall and flood in flood season has been one of the greatest natural calamities affecting the highway transportation all the time,restricting the social life and economic development.So,it is very essential to study the assessment and prevention measures of the highway washout by flood constantly.Mountain highway has its complex climate-hydrological and geological and topographical conditions.The highway subgrade washout by flood along rivers,which has numerous influence factors,various types,seasonality,great harmfulness and so on,takes up a great proportion out of highway washout.The occurrence uncertainty of it provides a precondition for the objective existence of highway washout risk.So,it is stronger pertinence and practicability to study washout mechanism,to choose the right evaluation index to carry on the risk assessment,and to propose reasonable protection form and non-construction hazard prevention and reduction measures finally.Combining with relevant research materials and investigation on field,based on system theory,the concept and properties of the highway washout system along rivers has been described,and washout type division method has been proposed,and the formation mechanism has also been studied systematically.Based on flood disaster risk management,a definitionon has been given to the washout risk of subgrade along river side,and the method of investigation and risk identification is put forward.Choosing hazard and vulnerability assessment factors,with the method of grey system incidence degree,fuzzy comprehensive assessment and economic total loss,the assessment of flood hazard,vulnerability and failure loss has been implemented,separately.On this basis,the assessment of the washout risk has also been carried out.In this thesis,various protection forms and applicable condition have been studied,and non-engineering prevention measures are offered.Scientific idea and technological countermeasure of the assessment and prevention measures should be carried out and planned in every stages of surveying,design and construction,maintain management in the highway engineering,to make the highway engineering coordinate with the natural environment,which is considered as the radical way out to treat highway washout by flood completely.