水域浅层地震反射波在珊瑚岛礁地层勘察中的应用

Shallow Marine Seismic Reflection Applied in the Investigation of Coral Island and Reef

珊瑚礁是一种特殊的岩土类型,工程特性研究是现代岩土工程的一个新课题,国内针对岛礁的工程勘察经验较少,没有成熟的勘察规范,由于岛礁勘察面临的异常恶劣条件,钻探手段有很大的局限性,在南海某岛礁的地质调查中,采用钻探与物探结合的方法。物探采用浅层水域地震反射波勘探方法,水域地震反射波对内礁坪、向海坡、潟湖、外海等不同礁相的沉积层界面反映清晰,取得了理想的勘察效果。

The coral reef is a special geotechnical type,its engineering characteristics is a new subject for the geotechnical engineer.There are fewer experiences in coral reef investigation,and no investigation code or norm exists at home.The borehole drilling is badly limited for the severe weather as well as the marine environment.Shallow marine seismic reflection is adopted in the investigation of a coral island in South China Sea,Combined with the borehole data,the seismic reflection figures out the geological stratigraphic sequence of coral clastic deposit and underlying reef limestone.The result achieved in depth mapping is quite satisfactory.It showes that the deposit interface in different reef phases is obvious,including of inner reef flat,atoll lagoon,seaward slope,offshore.Outer reef flat is somewhat unclear for the existence of hard modern beach rock.