CAJ | 학술논문

钙质砂是一种碳酸钙含量达50%以上的海洋生物成因的颗粒状材料。从微观结构上来看，钙质砂颗粒棱角度高、形状不规则、强度低、易破碎，且颗粒含有内孔隙。内孔隙的存在深刻影响着钙质砂的压缩、剪切和破碎等力学性能。利用激光技术对南沙群岛永暑礁环礁泻湖的未胶结钙质砂颗粒进行飞秒切割，通过光学显微镜探查并获取了颗粒的内孔隙图像，借助MATLAB图像处理软件，对钙质砂颗粒的内孔隙进行了定量分析。结果表明：较大颗粒钙质砂的内孔隙断面孔隙度相对较大，小孔隙数量较多，而大孔隙所占空间则较大；对于1 mm以上的钙质砂，缝隙状内孔隙含量远低于等轴或不等轴孔隙，等轴与不等轴内孔数量大致相等。
개질사시일충탄산개함량체50%이상적해양생물성인적과립상재료。종미관결구상래간，개질사과립릉각도고、형상불규칙、강도저、역파쇄，차과립함유내공극。내공극적존재심각영향착개질사적압축、전절화파쇄등역학성능。이용격광기술대남사군도영서초배초사호적미효결개질사과립진행비초절할，통과광학현미경탐사병획취료과립적내공극도상，차조MATLAB도상처리연건，대개질사과립적내공극진행료정량분석。결과표명：교대과립개질사적내공극단면공극도상대교대，소공극수량교다，이대공극소점공간칙교대；대우1 mm이상적개질사，봉극상내공극함량원저우등축혹불등축공극，등축여불등축내공수량대치상등。
Calcareous sands are consisted of marine biogenic granular materials with carbonate content often greater than 50%. From the microscopic viewpoint, calcareous sand grains demonstrate highly angular and irregular in shapes and contain intra-pores. This unique intra-pore structure of calcareous sand particle is prone to crush under stress. Therefore, the calcareous sand has a relatively low strength. The intra-pore structure has a significant effect on the geotechnical properties of calcareous sands. Calcareous sand samples from the lagoon of Yongshu Reef atoll, Nansha Islands, were cut by femtosecond laser for the optical microscopic studies. The intra-pore structures were quantitatively analyzed throughout the MATLAB digital image process tool. The results indicate that, larger porosity can be found on the breakage section of larger size calcareous sand and a larger number of small pores with small total volume are in the intra-pore structure. For sand grains with a size greater than one millimeter, the number of slit shape intra-pores is far less than the number of intra-voids with equiaxed or unequal axed pores. The amount of the equiaxed and unequal axed pores are approximately the same.