Analysis of Coral Reef Rock Mass Integrity Based on RMDI Method

Abstract

At present, relatively few drilling surveys have been conducted on coral reefs, and comprehensive geological info on coral reefs is difficult to obtain. However, research of coral reef is of great importance to our development and exploitation of maritime resources. The survey of Chenhang Island in Paracel (Xisha) Islands saw China’s first usage of digital borehole camera technology, which resulted in a large amount of first-hand geological data. We have utilized the rock mass integrity index (RMDI) method in our analysis of coral reef integrity, and with reference to the rock mass classification standard, formulated the correlation between RMDI values and coral reef intactness, enabling the engineering evaluation of coral reef integrity. Through statistical analysis of camera data gathered along the CK2 borehole’s approx. 1km length, we performed an integrity evaluation of the entire borehole length using the RMDI classification, and created a coral reef stratum development diagram which is consistent with the actual cores. The results indicate: (1) the classification system based on RMDI is feasible in the integrity evaluation of coral reefs; (2) the coral reef integrity values obtained using the RMDI method are accurate; (3) borehole camera survey and statistical analysis are of great utility in the study of coral reefs.