铁路工程建设水土流失监测试验研究——以北同蒲增建二线改造项目太原至原平段为例

在北同蒲增建二线改造项目太原至原平段水土流失监测过程中，根据建设责任区内的水土流失敏感点的土壤侵蚀特征采用了定点连续监测、定点定时监测和沿线调查三个不同层次的监测方法。铁路建设责任区域内的气象条件、土地利用形式和地形等水土流失影响因子的差异性导致了各水土流失敏感点的土壤侵蚀形式和特征的不同。项目建设期间产生的大型的裸露土体在侵蚀性降雨条件下其土壤特性变化明显，增加了区域内的产沙量；坡面土壤粒度的粗化和随机粗糙度的变化不一定会降低坡面上的面蚀强度。作为铁路建设重要工程主体的路堤和路堑的建设会改变区域内的产流、径流和渗流途经；在稳定和适宜的工程防护下，能够较好地控制开发建设项目径流产沙的增量。铁路建设中的水保设施本身的失稳也常常是增加产沙量的另一途经。

Monitoring on Soil and Water Conservation During the Construction of Railway Project

To carry out a monitoring on soil and water conservation at the section from Taiyuan to Yuanping in the project of Beitongpu second railway line located in Shanxi province,three monitoring schemes of different level,namely continuous measurement,periodic measurement and periodic reconnaissance,are employed according to the characteristics of soil erosion of the ground surface under study.Sampling and testing were done to the critical topographic units sensitive to soil erosion within the area subject to soil and water loss prevention.The climate conditions,types of land use and land topography along the railway line contribute to the diversity of styles and characteristics of soil erosion in those units.The precipitation comes in and is able to bring obvious change to the feature of bare soil that formed during construction.The change of granularity of the soil and the crust type of the ground surface do not necessarily help reduce the intensity of surface erosion on those lands.The construction of embankments and cuttings,which are main ingredients of the railway engineering,will inevitably influence the route of runoff and seepage,and increase sediment yields.However,proper means of engineering protection can help minimize the increment of soil erosion.The other reason augmenting soil erosion in engineering projects might come to be the instabilizing of the establishments of soil and water conservation themselves.