珊瑚礁岩土的工程地质特性研究进展

Research Progress in the Engineering Geological Characteristics of Coral Reefs

文章综述了珊瑚礁岩土工程的研究意义、珊瑚礁岩土的组成、钙质砂的物理性质、钙质砂的静力学特性、珊瑚礁岩土中的桩基工程、珊瑚礁混凝土等方面的研究现状。得出:1)颗粒易破碎是钙质砂最重要的特性,直接影响着钙质砂的其他力学性能,而影响钙质砂颗粒破碎的主要因素有围压、有效应力、颗粒级配、初始孔隙比、颗粒强度、颗粒形状等;2)生物颗粒的易破碎以及成桩过程对钙质砂结构的扰动,导致钙质砂中的桩基承载力远低于普通石英砂;3)在以珊瑚砂为原料的混凝土工程中,利用抗硫酸盐水泥拌养的珊瑚混凝土,其强度和耐久性相对较好。最后指出:加强对钙质砂颗粒破碎发生机理的研究以及建立破碎模型、加强对新型珊瑚礁钢筋混凝土和新型桩基的研究、开展珊瑚礁岩土工程的灾害预防与处理以及工程后期的养护等,是珊瑚礁岩土工程进一步研究的方向。

Coral reefs are a special geological structure developed in the tropical marine environment. The structure consists of coral reef and other marine organism fragments. This review is focused on the significance of studying coral reef engineering, composition of coral reefs, the physico-mechanical properties of calcareous sands, pile foundation engineering in coral reefs, and coral concrete. Particle crushing is the most important property of calcareous sands and affects other mechanical properties directly; and in turn, it is mainly affected by confining pressure, effective stress, grain composition, initial void ratio, particle strength and particle shape. Pile foundation bearing capacity in calcareous sands is lower than that in common silica sands due to particle crushing and disturbance of calcareous sand structure by the pile-forming process. In coral concrete engineering, concrete made with sulfate-resistant cement has good strength and durability. Future research should be focused on the mechanisms and modeling of particle crushing, new types of coral reinforced concrete and pile foundation, disaster prevention and management and later maintenance of coral reef projects.