珊瑚礁灰岩工程地质特性研究新进展

Advances in study of engineering geological characteristics of coral reef limestone

随着“一带一路”的实施和“海上丝绸之路”的部署,珊瑚礁灰岩工程地质特性研究具有实际的战略意义和迫切需要。通过纵横观对比分析南海、红海、加勒比海、东南亚、印度洋以及亚丁湾地区珊瑚礁灰岩基本物理力学特性,定量地展现了海相生物成因的珊瑚礁灰岩的特殊性。与石灰岩、白云岩等碳酸盐岩相比,珊瑚礁灰岩离散性较大,特别是孔隙率有所偏大,强度有所偏小,这与珊瑚等原生生物结构复杂、疏松多孔以及非均质性的固有特征相吻合,进而提出珊瑚礁灰岩物理力学特性具有“结构效应”。珊瑚礁体内部表现出软硬互层交替的垂直分带现象,究其原因是珊瑚礁灰岩孔隙发育程度不均匀、强度软硬不一以及结构构造无序性的整体宏观体现,从某珊瑚礁体地层划分的角度定量地揭示了珊瑚礁岩体的“成岩作用类型交替演化效应”。

The research on engineering geological characteristics of coral reef limestone has become a significant and urgent need in the region of“One Belt and One Road”and the“maritime silk road”.By comparing the physical and mechanical characteristics of coral reef limestone from the South China Sea,the Red Sea,the Caribbean Sea,Southeast Asia,the Indian Ocean and the Gulf of Aden,the characteristics and properties of marine biogenetic coral reef limestone are studied in this paper.It is found that Compared with normal carbonate rocks,such as dolomite and limestone,the coral reef limestone is characterized by large discreteness.Its porosity is larger and intensity lower,due to its complicated texture.As the results,the engineering and mechanic properties of the coral reef limestone is obviously controlled by the texture of the rock,we called it the“texture effect”in this paper.In vertical sequence,coral-reef always shows alternation of hard and soft beds due to differentiation of pore development,as the results of“alternating evolution of diagenesis”.