Loess Roadbed Erosion And Control Techniques

Highway in bess regions is often washed out by water, because bess has collapsibility, special structural characteristics, physical and mechanical quality. Gansu province lies on typical bess plateau, and highway is seriously destroyed by water. How to study and explore highway washout and technology of prevention and cure systematically is very important. This thesis combines basic theory and practical investigation, links mach-judgment and micro-analysis, integrates qualitative research and quantitative calculation, makes use of system science-which crosses many kinds of courses-to guide it so that the other can analyses washout process and regularity of slope and shoulder of highway, and research technical policy and treasure to prevent highway from washing out. Loess erosion is mainly produced by rainfall. A series of hydraulic erosion emerges during rainfall, because of bad character and human influence. First, water is not only the most important control factor, but also the most sensitive inducement. Whether vertical corrosion and erosion of surface water or horizontal filter and sub- erosion of underground water will wreck road. Thus, the author sets up a frame in order to analyses these factors through detailed discussion of slopes, shoulders and cattail ditches and lower structure strait of pavement. After studying typical sections of washout, the author devisees then into natural and human ones, and uses fuzzy mathematics to pass judgment on single and Cory-round factors. At the same time, the stability evaluation of semi-quantitative analysis and formula of probability statistics are given. Last, technical policy and treasure are put forward. This sort of policy in clouds technology of prevention and drainage of slope of cutting and embankment, and drainage treasure of road-surface and roadbed. It is demonstrated that judging and forecasting the destroyed degree of highway is totally possible if only one is able to depend on correct basic theory, utilize economic and reasonable methods to investigate and research the factors, scientifically analyses and discuss them, find out all kinds of natural and human factors which influence washout of highway, combine qualitative and quantitative analysis together. On the other hand, the keys to above problems establish solid base for fellow research to prevent highway from washing out.