马尔代夫珊瑚礁岩土地层结构与波速特征

Soil Layer Structure and Wave Properties of Coral Reef in Maldives

马尔代夫地处热带海洋环境,珊瑚礁岩土广泛发育。通过工程地质钻探、室内试验和波速测试研究了珊瑚礁岩土的地层结构和波速特征。结果表明:马尔代夫珊瑚礁岩土由珊瑚砂和礁灰岩组成,根据颗粒组成可将珊瑚砂分为细中砂和粗砾砂,根据胶结程度可将礁灰岩分为块状礁灰岩和柱状礁灰岩;珊瑚砂的剪切波速随深度增加而增加,变化范围为156~370 m/s,等效剪切波速为262.3 m/s;根据完整性系数可将礁灰岩分为极破碎、破碎、较破碎、较完整和完整5类礁灰岩,礁灰岩呈现出较规律的沉积旋回。

Maldives is located in the tropical marine environment,with coral reef rock and soil widely developed.Through engineering geological drilling,laboratory test and wave velocity test,the stratigraphic structure and wave velocity characteristics of coral reef were studied.The results show that the coral reef soil in Maldives is composed of coral sand and coral reef limestone.According to the grain composition,the coral sand can be divided into fine medium sand and coarse gravel sand.According to the degree of cementation,the coral reef limestone can be divided into massive reef limestone and columnar reef limestone.The shear wave velocity of coral sand increases with depth,ranging from 156 m/s to 370 m/s,and the equivalent shear wave velocity is 262.3 m/s.According to the integrity coefficient,reef limestones can be divided into five types:extremely broken,broken,relatively broken,relatively complete and complete.Reef limestones show regular sedimentary cycles.