Highway Drainage System and It's Control Effect on Rainfall Erosion Chain

According to the investigation and experience of highway engineering,using the method of systematic analysis,the composition and division of systems and function of drainage system for highway are researched,and that the drainage system could be divided into the subsystem according to the corresponding converging area of the small bridges and culverts are proposed.It is point out the slope drainage system is a net system composed of intercepting and draining ditches.Meanwhile,aiming at the questions that the small bridges and culverts existed in designing and using,the research points out the important factor influencing design discharge of the small bridges and culverts.On the basis of introducing erosion chain theory,a new theory is raised: the key positions about the drainage system are in corners of several pieces of slope of subgrade section.Rational setting of the drainage system could control effectively the development that the slope is corroded,and lighten the rainfall runoff to hazard the highway.The rusults offer the reference for the highway drainage design and the preventing and reduction of hazard.