用数字图像处理技术进行膨胀红砂岩细观结构动态劣变特征研究

针对南京红山窑水利枢纽工程红砂岩具有微膨胀、易风化、易湿化的特点,采用扫描电子显微镜、X射线衍射仪、MTS81503岩石力学刚性电液伺服试验机等先进设备为测试手段,获得大量红砂岩在不同吸水时间下的细观结构照片,并对图片进行灰度处理,提出用数字图像相关技术处理不同含水状态下红砂岩试验随时间动态劣化过程的灰度分布图;进一步探讨不同注水时间的红砂岩细观结构劣变状态及裂纹扩展的定量描述,从而为分析与定量评价膨胀红砂岩随时间膨胀变形破坏机制,寻求一种可靠的研究方法.这一结果对南京红山窑水利枢纽工程地基处理方案设计与施工具有重大的参考价值.

RESEARCH ON MESOSTRUCTURE DYNAMIC DAMAGE CHARACTERISTICS OF EXPANSIVE RED SANDSTONE WITH DIGITAL IMAGE PROCESSING TECHNIQUE

The red sandstone of Hongshanyao Hydraulic Project in Nanjing has characteristics of microdilatancy and is easy to be weathered and wetted.By using the advanced equipments such as SEM,X-radial diffraction instrument,rock mechanics testing machine of MTS81503 and so on,a lot of mesostructural pictures of red sandstone with different water contents are obtained;and the gray level thresholding is done with these images.The paper puts forward the digital image processing technique to deal with gray distribution pictures of red sandstone in different dynamic damage stages with different water contents.Further studies on the mesostructural changes of red sandstone in different damage states with different water injection times and crack propagation are discussed quantitatively.The aim of this paper is to bring forward a reliable research method to analyze and evaluate quantitatively the expansive deformation failure mechanism of expansive red sandstone with time.The research results have momentous reference value for foundation treatment design and construction of Hongshanyao Hydraulic Project in Nanjing.