基于航空影射测量技术的岩质边坡裂隙孔径解译方法研究

Research on Interpretation Method of Rocky Slope Fissure Aperture Based on Aerial Shadow Measurement Technology

天然岩石裂隙的孔径对岩体的变形与强度特性以及裂隙岩体的水动力特性有显著影响,而传统的测量方法对于复杂山区高陡岩质边坡的数据采集不够精确。针对该问题,通过无人机多角度拍物摄影测量技术,建立岩石边坡高分辨率三维模型,获取裂缝边缘特征点,借助坐标投影和变换对裂缝张开形态进行表征,并利用垂直测量线确定裂缝中轴线,根据裂缝的形状解释孔径。以山西省某铁路施工现场为例,验证该方法的可行性和可靠性。研究表明,裂缝孔径具有显著的区间效应和尺寸效应,裂缝的最佳采样长度约为0.5~1 m,当测量线间距为采样长度的1%时,可以获得最佳的孔径解释结果,同时不同方位裂缝的孔径分布存在一定差异,但一般服从正态分布、对数正态分布和伽马分布。

The aperture diameter of natural rock fissures has a significant effect on the deformation and strength characteristics of the rock body as well as the hydrodynamic characteristics of the fissured rock body,while the traditional measurement methods are not accurate enough for data collection of high steep rocky slopes in complex mountainous areas.In order to address this problem,the high-resolution three-dimensional model of rock slope is established through the UAV multi-angle object photogrammetry technique,the characteristic points of crack edges are obtained,the crack opening morphology is characterized with the help of coordinate projections and transformations,and the vertical measurement line is used to determine the central axis of the crack,and the aperture is interpreted according to the shape of the crack.The feasibility and reliability of the method is verified by taking a railroad construction site in Shanxi Province as an example,and the study shows that the crack aperture has significant interval effect and size effect,and the optimal sampling length of the crack is about 0.5~1 m.The best aperture interpretation results can be obtained when the spacing of the measurement line is 1%of the sampling length,and meanwhile,the distribution of aperture in cracks of different orientations varies to a certain extent,but it generally obeys the normal,lognormal,and gamma normal distributions.