Research Of Stability Analysis Of Roadbed Considering Extreme Snow Disaster

Extreme snow disasters happened in southern China at the beginning of 2008 year. Now southern China is mostly classified as the third climatic zone in accordance with standards for the construction of climate divisions. At present, China still lacks a perfect and comprehensive prevention system to respond to disasters of roadbed which inducing by extreme snow, and there is also a lack of an effective engineering control measures and emergency treatment measures which leading to a more passive disaster When facing the extreme snow disaster. In order to study the influence of extreme snow on stability of the highway roadbed, this paper will analyze the influence on t factors of the highway f roadbed stability. With the current design specifications, highway foundation stability analysis method was proposed, which according to structural reliability design concept. Calculation and experimental test were down.The main research work of this thesis and achievements are as follows:â‘ The analysis of the current extreme snow disaster was completed and collation of embankment stability information which responded to extreme snow was analysis. According to the existing conditions of embankment stability analysis, the calculation formula of highway foundation stability in condition of extreme snow disaster was derived. The main factor affecting embankment stability was also summed up.â‘¡To verify the need to amend the formula of the stability for the roadbed under extreme snow, here typical red clay of southern China was collected. Upon completion of the regular testing of soil mechanics parameters, extreme snow conditions were simulated. The test of direct shear test, unconfined compression strength, frost-heaving ratio, and also dry density, water translocation were accomplished. Freeze-thaw frequency, moisture content and stability of the conditions on the impact of soil physical parameters were studied.â‘¢Firstly, the calculation formula of the safety factor on toppling stability in condition of extreme snow disaster was derived, and also the expression of sliding stability factor for the classic rock slope subgrade. Secondly, through the calculation and analysis, the variation law of the safety factor with the changes of slope angle, slope height, the dip angle of the slide plane, the depth of tension fractures for saturated rock slope was revealed, so was the relationship between the factor and frost depth. Figures that express relationship of safety factor on toppling stability against geometric factor were drawn.â‘£The principle of subgrade disaster prevention was put forward, which considers the pathogenesis of roadbed disasters and the characteristics of subgrade destruction under extreme snow. A reasonable model of control methods for different types of roadbed disasters has been proposed.