基于图像数字技术的砂岩裂隙可视化渗流特性试验研究  

Experimental research on visible seepage of sandstone fissure using digital image-based method

作　　者：刘杰[1,2] 唐洪宇 杨渝南[1,2] 石谦 李政[1,2] 黎照 高进 兰俊 LIU Jie;TANG Hong-yu;YANG Yu-nan;SHI Qian;LI Zheng;LI Zhao;GAO Jin;LAN Jun(Engineering Technology Center for Geological Disaster Prevention of Hubei Province,Yichang 443002,China;Key Laboratory of Geological Hazards in Three Gorges Reservoir Area,Ministry of Education,Yichang 443002,China;Wuhan Tianhua Huazhong Architectural Design Co.,Ltd.,Wuhan 430021,China)

机构地区：[1]三峡大学湖北省地质灾害防治工程技术中心,湖北宜昌443002 [2]三峡大学三峡库区地质灾害教育部重点试验室,湖北宜昌443002 [3]武汉天华华中建筑设计有限公司,湖北武汉430021

出　　处：《岩土工程学报》2020年第11期2024-2033,共10页Chinese Journal of Geotechnical Engineering

基　　金：湖北省技术创新重点项目(2017ACA189);国家自然科学基金项目(51579138);湖北省自然科学基金杰出青年人才计划项目(2018CFA065);湖北长江三峡滑坡国家野外科学观测研究站开放基金项目(2018KTL08);湖北省自然科学基金一般面上项目(2020CFB584)。

摘　　要：自主研发的可视化裂隙渗流试验装置,应用颜色示踪的图像数字化处理技术,在不同渗透压和法向应力分级加卸载耦合作用下,进行空间垂直角度的砂岩裂隙可视化渗流试验。通过毫秒级分帧技术捕捉裂隙渗流状态并对渗流面积色域分区,基于数字化图像技术进行二值化处理,通过图层二次叠加渲染,自识别渗流面积参数,建立渗透压与法向应力作用下的渗流面积扩散规律。研究裂隙渗流优势路径各断面的过流宽度变化特征,提出可视化渗流速度求取公式,指出渗流速度沿流径变化为骤增、骤降、均匀损耗3个阶段,建立最小断面宽度对应的峰值流速与渗透压和法向应力耦合作用下的函数模型。基于实测数据建立主渗流路径中法向应力、渗透压与雷诺数的幂函数关系,标定渗流状态的惯性作用区与黏性作用区的转变临界点,构建可视化裂隙渗流雷诺数预测模型,对裂隙渗流中真实渗流路径识别、流速矢量实时变化、流体状态判定等关键科学问题提出了新的研究理论及方法。The visual fracture seepage test devices independently developed apply the color tracer image digital processing technology to carry out the visual seepage tests on the sandstone fractures with vertical spatial angle under the coupling effects of loading and unloading with different osmotic pressure and normal stress gradations.By means of the millisecond frame division technology,the seepage state of the crack is captured and the color domain of the seepage area is partitioned.Based on the digital image technology,the binary processing is carried out.The parameters of the seepage area are identified by double overlay of layers,and the diffusion law of the seepage area under the action of osmotic pressure and normal stress is established.The characteristics of the change of the flow width of each section along the dominant seepage path of the fracture are studied,and the formula for calculating the visual seepage velocity is put forward.It is pointed out that the seepage velocity changes along the flow diameter into three stages:sudden increase,sudden decrease and uniform loss.A functional model for the peak velocity corresponding to the minimum section width is established under the coupling action of osmotic pressure and normal stress.Based on the measured data of the main seepage path,the power function for the stress normal,osmotic pressure and Reynolds number is established,the change point of seepage state in the inertia function area and viscous effect area is calibrated,and the prediction model for Reynolds number of visualized fissure flows is formulated.The new theories and research method for the key scientific issues such as identification of real seepage in fissure seepage path,real-time change of velocity vector and determination of fluid state are put forward.

关 键 词：可视化渗流 图像数字化处理 渗流扩散面积 过流断面宽度 渗流速度 雷诺数 

分 类 号：TU411[建筑科学—岩土工程]