Highway Drainage Techniques In Collapsible Loess Areas

Collapsible loess broadly distributes in Northwest China, North China receive extensive areas of collapsible loess distribution to highway construction and maintenance, and have brought great difficulties, causing substantial economic loss. 2003 rain cut most areas of northern China, the loess region is no exception. Because big rainfall in Shaanxi Province, roadbed depression in northern Shaanxi became widespread , resulting in direct economic losses amounting to tens of millions of dollars of road. Roadbed depression is the primary cause of internal collapse, external causes rainfall is the formation of surface water and groundwater moving.Contacting with the actual project, analyzed the reasons, condition and influence of loess collapse, and knew that water have great relations with loess collapse. Collapse is the characteristic of loess and actual project is large-filled, therefore, it is impossible to change all the loess. To prevent the roadbed collapse, preventing water is a source of effective channels.Analyzed the design and construction of drainage facilities used by the highway, and focus on the loess areas ditch drainage, road surface drainage, the central belt drainage and underground drainage. And measures are proposed to improve the ditch side of road design methodology and design steps.Collapse loess area especially loess hills, the terrain is complicated and changeable, and drainage design will not have a uniform model, drainage design is the key to the systemic and drainage facilities commensurate with the terrain. This article analyses the interaction between the type of drainage, including drainage and road drainage roadbed integration, the integration of surface drainage and underground drainage, drainage facilities to ensure the integrity and systemic.