Study On Montane Railway Subgrade Water Disasters Mechanism And The Development Of Early Warning System

Natural disasters have always been the major challenges for the railway construction in China. Considering the rapid development of railway construction, the designed water disasters mechanism study and warning are by no means a significant guarantee of construction and protection in montane railway, especially in terms of the complicated montane topography and changeable climate. Rainfall can not be over looked. Recently heavy shower occurs, greatly threatening the safety of railway construction,transportation operation and people’s lives and properties in our country. This thesis focuses on characteristics of montane railway subgrade water disasters and concludes the following ideas:Firstly,by arranging and analyzing a large amount of datum,the produce conditio-ns, disaster mechanism, prevention measures, and types of washout of railways were summarized; the periodic division of rainfall and the interaction between the rainfall and slope were studied, the formation mechanism process of water disasters was ana-lyzed and the corresponding prevention measures were investigated.Secondly,based on Darcy’s law, and combined with the two dimensional Richards equations and Van Genuchten model, it has built the model of the Calculation model of rainfall slope seepage using the simulation software of COMSOL Multiphysics. Through the contrast and analysis of influence of seepage on slope of differential coefficient of infiltration under different rainfall intensities and different rainfall duration, conclusions gained are as follows:the effect of rainfall on the variation of pore water pressure is on the same trend under the condition of different permeability coefficient; the rainfall intensity is inversely proportional to the time required to complete the seepage stability; the variation of pore pressure and groundwater rise is proportionate to the permeability coefficient; The ultimate value of pore water pressure is linear with the observation depth basically; the soil shear strength decreases gradually and the global stability gradually reduce in the process of the volumetric water content gradually increases and reaches saturation.Thirdly,based on the historical water disasters warn and forecast theory, a model of rainfall warn threshold value was established by analyzing the rainfall and disasters data of Baoji-Chengdu railway. And based on the model, the cautionary grades of water disasters rainfall were categorized as the Attention, Speed Limit, and Blockade, respectively using yellow, orange, and red to intuitively distinguish the cautionary grades.Finally,using C# and SQL2008 database to prepare the early warning management system software of water disasters,establishing early warning management platform of railway water disasters in mountain areas.Including the basic parameters of railway project querying and management system,analysis of monitoring data management system,the decision of early warning information release system and rescue management system.