RUI: Development of a Textural Weathering Classification for Limestone Using Signal Processing Techniques

风化对岩石的强度和硬度有负面影响。当建筑和桥梁的隧道和基础被设计成由风化岩石支撑时，了解强度和刚度下降的幅度是很重要的。目前，风化作用是通过对岩石样品的目视描述来评估的。以前的研究表明，从肉眼上很容易区分未风化和高度风化的样品，但中等风化状态的样品往往被错误分类。该奖项支持基础研究，以开发一种基于测量的石灰岩样品风化分类系统。基于测量的系统将比基于视觉的系统更准确，并导致更经济和可持续的风化岩石支撑基础设施设计。这项工作也可用于评价岩石节理粗糙度，从而获得更安全、更经济的岩质边坡。因此，这项研究的结果将有利于美国的经济和社会。这项研究涉及土木工程和电气工程专业的本科生。这种多学科的方法将有助于扩大未被充分代表的群体在研究中的参与，并对本科水平的工程教育产生积极影响。这项工作将开发第一个可量化的基于质地的石灰岩风化分类系统。该系统将基于样品中贝壳化石的百分比和大小、通过表面表征确定的微观地形以及使用信号和图像处理算法量化的粗糙度。将使用工业剖面仪、三维激光扫描仪和近距离摄影测量来进行表面表征。粗糙度通常使用基于二维幅度的算法来表征。这项工作将结合基于频率的算法，并将粗糙度评估扩展到三维。风化分类系统将以常见的用于岩体分类的地质强度指数系统为基础。

Weathering has a negative effect on the strength and stiffness of rock. When tunnels and foundations for buildings and bridges are designed to be supported by weathered rock, it is important to understand the magnitude of the decrease in strength and stiffness. Currently weathering is assessed using visual descriptions of rock specimens. Previous studies have shown it is very easy to visually distinguish unweathered and highly weathered specimens but specimens with intermediate weathering states are often misclassified. This award supports fundamental research to develop a measurement based weathering classification system for limestone rock specimens. The measurement based system will be more accurate than the visual based system and lead to more economical and sustainable designs of infrastructure supported by weathered rock. This work can also be utilized for the assessment of rock joint roughness which can lead to safer and more economical rock slopes. Therefore, results from this research will benefit the U.S. economy and society. This research involves undergraduate students in both civil and electrical engineering. The multi-disciplinary approach will help broaden participation of underrepresented groups in research and positively impact engineering education at the undergraduate level.This work will develop the first quantifiable textural based weathering classification system for limestone rock specimens. The system will be based on the percentage and size of fossilized shells in the specimens, the micro-topography determined through surface characterization, and roughness values quantified using signal and image processing algorithms. Surface characterization will be performed using an industrial profiler, a three-dimensional laser scanner, and close range photogrammetry. Roughness is typically characterized using two-dimensional magnitude based algorithms. This work will incorporate frequency based algorithms and extend roughness assessment to three-dimensions. The weathering classification system will be based on the familiar Geological Strength Index system used for rock mass classification.