Friction angles at sandy beaches from remote imagery
Friction angles at sandy beaches from remote imagery
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远程图像显示沙滩上的摩擦角
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
P. Mallas
中科院分区：
文献类型：
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作者：
N. Stark;J. McNinch;H. Wadman;H. Graber;A. Albatal;P. Mallas
探索了在沙滩环境中通过数字图像（视觉光谱）确定的坡度角提取摩擦角以及最终下限承载强度的严格性。使用手持式摄像机、无人机和全色卫星传感器对地形沙地特征的数字图像进行分析，以使用三维重建确定平均坡度角。卫星图像中利用灰度梯度和阴影来提取坡度估计值。倾斜角度与来自北卡罗来纳州达克和弗吉尼亚州克莱托湖现场相同位置的样品的倾斜表结果相匹配。样品材料的直接剪切测试表明摩擦角分别为~33°和~35°。作者测试了利用这些遥感坡度得出下限承载强度的潜在途径。初步结果令人鼓舞，但可能对含水量的影响、最大坡度角和观察到的坡度角以及内部坡度之间的差异敏感。
The rigour of extracting friction angles, and eventually lower-bound bearing strength, in sandy beach settings through slope angles determined from digital images (visual spectrum) is explored. Digital images of topographic sand features using hand-held cameras, an unmanned aerial vehicle and a panchromatic satellite sensor are analysed to determine average slope angles using three-dimensional reconstruction. Greyscale gradients and shadows are utilised in the satellite images to extract slope estimates. The slope angles matched tilt table results of samples from the same locations at the Duck, NC, and Claytor Lake, VA, field sites. Direct shear testing of sample material suggest friction angles of ∼33° and ∼35°, respectively. The authors test a potential pathway to derive lower-bound bearing strength using these remotely sensed slope angles. Preliminary results are encouraging, but likely sensitive to the impact of moisture content, differences between the maximum and the observed slope angle and interna...