基于CT扫描试验的珊瑚骨架灰岩孔隙结构特征研究  

STUDY ON PORE STRUCTURE CHARACTERISTICS OF CORAL SKELETON LIMESTONE BASED ON CT SCANS

作　　者：张标 雷学文[1] 魏厚振[2] 孟庆山[2] 李肖肖 王新志[2] ZHANG Biao;LEI Xuewen;WEI Houzhen;MENG Qingshan;LI Xiaoxiao;WANG Xinzhi(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]武汉科技大学城市建设学院,武汉430065 [2]中国科学院武汉岩土力学研究所,岩土力学与工程国家重点实验室,武汉430071

出　　处：《工程地质学报》2021年第6期1692-1699,共8页Journal of Engineering Geology

基　　金：国家自然科学基金(资助号:41877260,41877267);中国科学院战略性先导科技专项(资助号:XDA13010200).

摘　　要：为了探究分布于某岛礁珊瑚骨架灰岩的微观孔隙结构特征及其定性定量分析,选取6块有代表性的珊瑚骨架灰岩岩样,开展CT扫描试验,建立珊瑚骨架灰岩三维立体数字模型,获得三维数据体并开展孔隙结构特征的研究。结果表明:6块岩样整体孔隙率均值仅为3.30%,孔隙发育程度较小;岩样逐层面孔隙率有较大程度波动,面孔隙率较小,但其标准差却较大,体现了岩样较强的非均质性;对岩样三维模型中所提取的孔隙进行标记筛分,同时对孔隙体积与数量进行概率统计,结果表明珊瑚骨架灰岩中大孔隙数量虽少,但体积占比很大,存在极个别超大孔隙;通过球棒模型分析可知,配位数主要分布区间为0~2,说明珊瑚骨架灰岩的孔隙连通性较差,主要以独立孔隙和单连通孔隙为主,孔隙在x/y/z方向均无连通性,不存在潜在的流体运移通道。This paper aims to explore the microscopic pore structure characteristics and qualitative and quantitative analysis of coral skeleton limestone distributed on a certain island reef.We established the three-dimensional digital models for six representative coral skeleton limestone samples through CT scans and studied the pore structure characteristics.The results show that the overall average porosity of the six rock samples is only 3.30%,which indicates a small degree of pore development.The porosity of the rock samples fluctuates greatly from layer to layer.The porosity is small,but its standard deviation is large,which reflects the heterogeneity of the rock sample.We marked and screened the pores extracted from the 3D model of the rock sample,and carried out statistical analysis of the pore volume and quantity.The data shows that although the number of macropores in coral skeleton limestone is small,the volume of macropores accounts for a large proportion.There are some super large pores.Through the ball-and-stick model analysis,it can be found that the main distribution range of coordination numbers is 0~2,indicating that the pore connectivity of coral skeleton limestone is poor.The pores are mainly independent pores and single connected pores.The pores have no connectivity in the x/y/z direction,which means that there is no potential fluid migration channel.

关 键 词：珊瑚骨架灰岩 孔隙结构 CT扫描试验 孔隙三维模型 

分 类 号：P642.3[天文地球—工程地质学]