Ecological Waterproofing And Drainage Technology Research On The Karst Area

China is a country in the world where karst is widely distributed, and the total area of karst approximates 3.63 million km2, accounting for more than 1/3 of the proportion of the total land area. Karst landform has the characteristics of wide distribution as well as rather large areas. The karst water environment is very fragile, so highway construction in karst area is likely to cause damage to the environment of water. Once destroyed, it is difficult to restore. The unreasonable economic activities will result in serious loss of soil and water in many places and frequent disasters of all kinds, which hinder the development of the national economy in Karst area.This paper aims to study karst area highway drainage and ecological environment protection in harmony, designed to meet the requirements of the drainage system of ecological protection, the protection of vegetation along the road and the water environment.The purpose of this paper is to study how to make the karst area of highway drainage and protection of ecological environment in harmony, rational design to meet the requirements of the ecological protection and drainage system and the protection of vegetation and water environment along the highway.Taking into account the fragile ecological environment in the karst area, the amount of excavation should be reduced as far as possible during the construction in the area, so as to maintain the ecological balance of the original. This paper further puts forward the shallow dish shaped grass ditch. However, the factors which can influence the capacity of shallow dish shaped grass ditch are the cross section area, the slope rate of the bottom ditch and the roughness coefficient of the wall surface of the ditch. But as for the given the uniform flow in open channel, changes in roughness coefficients affect the drainage capacity of the channel.The indoor model test studying the flow characteristics of the Eco grass ditches, systematically researches 5 groups of different flow rate of the grass and non-grass ditch, and then analysis through the test data with the hydraulic, the results show that,In the case of water flow,the roughness coefficient of the grass side ditch is 0.03. At the same time, the grass in side ditch changes the internal structure of the original water in a large extent. Compared with a concrete ditch, the roughness coefficient of grass ditch increases, the flow rate decreases, the water level rises and the hydraulic radius increases. Roughness coefficient of side ditch changes as other hydraulic elements do, which is not a constant. The increase of flow rate will cause the decreasing of roughness coefficient. Roughness coefficient shows a downward trend with the increase of Reynolds number of Characterization of flow state and the Buddha characterization of Froude number, and the correlation coefficient between the fitting formula with the Froude number is 0.9974, showing that the fitting relationship is very good.According to the analysis of indoor ecological side drain model test, combined with the special geology of karst area and the principle of ecological drainage of highway in karst area, the design parameters for ecological water in karst area is proposed, aiming to provide certain reference value for the similar construction in the karst area in the future.