陕北油田黄土工区道路冲蚀灾害模型试验研究

Model Test Study on Road Erosion Disaster in Loess EngineeringArea of Northern Shaanxi Oilfield

为探究陕北油田黄土工区道路冲蚀灾害特征及路面细沟冲蚀影响因素,采用物理模型试验,对道路细沟冲蚀发育过程,不同工况下细沟长度、平均宽度以及平均深度的发展特征和产沙速率变化规律进行了研究。结果表明:细沟的发育过程可分为面蚀阶段,跌坑形成阶段,细沟发育阶段,切沟侵蚀、崩塌阶段4个阶段。细沟长度、平均宽度和平均深度与放水时间成幂函数关系,随着放水时间的增大而增大。其中细沟长度随着试验时长的增加先急剧增加,然后逐渐减少;细沟平均宽度随试验时长的增加总体呈现先快速增加后增加速度减慢;平均深度变化速度均在某一时刻达到拐点,流量越大达到拐点的时间越早。冲蚀灾害受流量和坡度影响显著,总体上随着坡度和流量的增大而增大;产沙速率总体上与流量呈线性关系,在其他条件一致的情况下,产沙速率随着流量的增大而增大;与南部的粉黄土和黏黄土相比,陕北油田工区的砂黄土产沙速率明显偏大,冲蚀灾害更为严重。

In order to explore the characteristics of road erosion disasters and the influencing factors of road surface erosion in the loess area of northern Shaanxi Oilfield,physical model tests were used to study the erosion development process of road fine trenches,the development characteristics of fine trench length,average width and average depth under different working conditions,and the variation law of sand production rate.The results show that the development process of fine groove can be divided into four stages:surface erosion stage-pit formation stage-fine furrow development stage-trench erosion and collapse stage.The length,average width and average depth of the fine trench are a function of the power of the water release time,and increase with the increase of the water release time.Among them,the length of the fine groove first increases sharply with the increase of the test duration,and then gradually decreases.With the increase of the average width of the fine groove with the increase of the trial duration,the overall increase first increases rapidly,and then the increase rate slows down.The average depth change rate all reaches the inflection point at a certain moment,and the larger the flow,the earlier the inflection point is reached.Erosion disasters are significantly affected by flow and slope,and generally increase with the increase of slope and flow.The sand production rate is generally linear with the flow rate,and under other conditions,the sand production rate increases with the increase of the flow rate.Compared with the silty loess and clay loess in the south,the sand loess production rate in the oilfield area of northern Shaanxi is significantly larger,and the erosion disaster is more serious.