全风化花岗岩路堑边坡降雨侵蚀时空分布特征测试与评估

Test and evaluation of spatiotemporal distribution characteristics of fully weathered granite cut slope under rainfall erosion

为了测试及评估全风化花岗岩路堑边坡降雨侵蚀时空分布特征,选取在建云南墨临高速公路某全风化花岗岩路堑边坡某段开展现场测试。首先结合三维激光扫描测试及电测量技术,获取边坡坡面形态特征参数及边坡电阻率剖面;然后引入高斯分布模型及分位数图示法实现边坡材料属性定义,通过电阻率差异映射边坡侵蚀状态。结果表明:边坡底部及坡中部(y=0~40 m)区域呈现大面积侵蚀特征,在各级边坡平台处则呈现多点集中高侵蚀特征,侵蚀影响深度达5 m左右;随着植被防护等措施的施加,大面积侵蚀特征变为多点集中侵蚀特征,评估结果与坡面形态信息具有较好的一致性。该研究成果对于该边坡降雨侵蚀灾害防治具有重要的实际意义,并对同类研究具有借鉴作用。

To test and evaluate the spatiotemporal distribution characteristics of fully weathered granite cut slope under rainfall erosion, the fully weathered granite cut slope of Yunnan Molin Highway under construction was selected for field test.Firstly, combined with three-dimensional scanning test and electrical measurement, the shape characteristic parameters and slope resistivity profile were obtained;then, the normal distribution model and quantile-quantile plot method were introduced to define the material properties of the slope, mapping slope erosion state with resistivity differences.The results show that large-scale erosion characteristics can be observed in the area at the bottom and middle of the slope(y=0~40 m),while multi-point concentrated erosion characteristics can be observed in the area at slope platforms, and the erosion depth is about 5 m.With the application of vegetation protection, large-scale erosion has transformed into a multi-point concentrated erosion, and the evaluation results have good consistency with the shape characteristic parameters.The research has practical significance for the rainfall erosion disaster prevention, and can also be used as a reference for similar research.