天然胶结钙质土强度及微观结构研究

自20世纪80年代起，国内就开展了关于岛礁钙质土岩土工程性质的研究工作，至今已经取得了大量的研究成果，但上述研究工作均是针对松散钙质土进行的，针对岛礁上广泛分布的胶结钙质土的研究工作尚未系统开展。而国外大量工程实践表明，胶结钙质土具有完全不同于松散钙质土的工程性状。针对天然胶结钙质土的空间各向异性，从微观角度研究影响其强度的主要参数，为今后的胶结钙质土的分类研究提供理论指导。文中采用多种试验研究方法，最后建立了天然胶结钙质土的密度、胶结度、孔隙度、颗粒大小等参数与强度间的对应关系，当前的研究结果表明，天然胶结钙质土的密度及胶结度与强度间存在良好的相关性。

Investigation on strength and microstracture of naturally cemented calcareous soil

The geotechnical properties of the coral reef materials widely distributed in all islands in South China Sea have been extensively studied since 1980s in China. However, the majority of these researches are focused on the uncemented calcareous sandy soils and limited studies are available on the engineering properties of the naturally cemented calcareous soils such as calcarenites, which are the prevailing materials at the coral reefs in South China Sea. The state-of-the-art engineering practices in the calcareous soils worldwide indicate that the geotechnical properties of the cemented calcareous sandy soils are significantly different from those of uncemented coral reef soils. Considering the spatial heterogeneity of the naturally cemented calcareous soils, this paper presents factors that affect the strength properties from the microscopic studies. The correlations between the strength of the cemented calcareous sandy soil sample and various parameters, such as unit weight, cementation degree, void ratio, shape of grain as well as grain size, are established from the test results. The results show that good correlations exist between the strength with the unit weight and the degree of cementation of the calcareous sandy soils.