Study On Theories And Methods For The Optimization Designation To Highway's Cutting High Loess Slope

Based on plentiful productive practice of highway engineering in the loess area in our country and a great deal of high loess slopes instances as well as their research results from domestic and foreign, a series of new theories and methods for highway 's cutting high loess slope optimization designation is studied by theories and methods, which has borrowed from geology, soil mechanics, thermodynamics, mathematics, operational research, modern computational method and computer modeling technique. System optimization is their predominant idea and the high loess slopes in the highway from HuangLing to Yannan is their supported engineering. Computing results of representative high loess slopes shows that these new theories and methods can provide a series of base of theory and technical guidance for cutting high loess slope optimization designation, which can make the slope more stability and reliable, more economy, more advantage for construction and more beautiful for highway. This research has important operational significance for the improvement of specification used now, which meet the requirement of the highway construction development in the loess area in our county.The major research fruits achieved in this paper were described as follows.1. Based on the result of the investigation for the high loess slope's failure face, in this paper the failure face was looked as parabolic line, to set a limiting equilibrium equation, build an equation for search the most dangerous sliding face was built using the integration method. This theory and method has been proved simplicity, quickly, and facilitate promotion by the practice2.According to the theory of mechanics and conservation of energy, a theory formula integration angle of slope for cutting high loess slope was set up, because of the stress variation in the cutting soil mass and the mechanical property ,this formula can provide base theory for the angle of slope designation, so it can avoid blindness.3. After determining the variable quantities, Object function and limiting factors, a model of cutting high loess slope optimization designation based on least cost method was set up. The analytical method in reliability which provided by Fiessler was used in the reliability computation for cutting high loess slope. Because it was used according with the standardized variable value, the method was more convenient than the JC method.4. A model of cutting high loess slope optimization designation based on the slope surface stability was set up after the erosion experimentation inside and outside and theory deduction.5. A model of cutting high loess slope's reasonable section optimization decision based on subjective and objective weights fuzzy recognition was set up, which can...