高速公路建设中水土流失预测模式研究

Research on New Mode for Water and Soil Erosion Prediction in Expressway Construction

针对山区高速公路建设的特点和可能造成水土流失的影响及其分布特性，根据国内外对水土流失预测的研究现状，选择了位于西南土石山区108国道西攀高速公路在建路段的黄水互通式立交A匝道开挖边坡和K11＋100-K11＋210路段左侧的弃渣场进行了观测试验，通过15次降雨量和水土流失量的实测，经过降雨强度、各时段降雨动能、降雨总能量参数单因子和复合因子与土壤流失量的相关分析，得出试验区的天然降雨雨滴中数直径与雨强的对数关系和单位降雨强度与降雨动能的关系；初步提出适用于高速公路建设土壤流失预测中的降雨侵蚀力的计算公式、土壤可侵蚀因子值；修正了经验法中的加速侵蚀系数A值。

On the basis of characters of expressway construction in mountain area and probable effects of water and soil loss caused by which and which distribute characters, and research progress of forecasting of soil and water loss both at home and abroad, two research areas are selected to carry out observation experiment, including cutting slope of A ramp of Huangshui Interchange area in construction line 108 Xi-Pan Expressway in west-south earth-rock mountain area and deposit area leftward K11＋ 100- K11＋210. According investigation for rainfall and quantity of water and soil loss 15 times, the correlation between rainfall intensity, rainfall energy of all period, rainfall overall energy factors and quantity of water and soil loss are analyzed, the conclusion is following： firstly, the logarithmic relationship between natural raindrop median diameter and rainfall intensity, and relationship between unit rainfall intensity and rainfall energy are acquired; secondly, the calculating formulas of rainfall erosion and factor value of soil erosion applied for forecasting of soil and water loss during expressway construction are preliminarily provided; thirdly, the accelerated erosion coefficient A value of empirical formula is modified.