福建兴化湾黄瓜岛海底电缆路由区工程地质特征及评价

基于福建兴化湾黄瓜岛海底电缆路由勘测中地形及水深测量、旁侧声呐探测、单道地震探测、沉积物的表层及柱状采样分析等多种勘测技术所获取的资料,结合区域地质背景对路由区工程地质条件进行了分析和研究。结果表明:路由区整体上工程地质特征等条件适宜海底电缆的铺设;路由区主要工程地质问题是两侧近岸段广泛出露的礁石及基岩浅埋区;路由区分布有海积软弱淤泥层以及细粒砂质层,存在震陷和液化的可能。此外,根据表层沉积物粒度分析结果反映出路由区沉积环境不稳定,局部水动力条件较强,潮流也具备一定的冲刷能力,在海缆设计和施工时需着重注意。

Engineering Geological Conditions and Evaluations of Huanggua Island Submarine Cable Route Area in Xinghua Bay,Fujian

Using the data acquired from an integrated survey involving echo -sounding , side-scan sonar detecting , single-channel seis-mic profiling, sediment surface sampling and gravity core sampling , the paper aims to study in detail the engineering geological conditions and evaluations of the Huanggua Island submarine cable route area .We find that the general engineering environment in this routing sea ar-ea is suitable for submarine cable -laying.The biggest obstacle is that reefs and shallow bedrock are distributed at near -shore seabed a-round each end of the route .The distribution of soft silt layer and fine -grained sandy layer will probably lead to seismic subsidence and sand liquefaction, respectively.Moreover, the grain-size analysis of the submarine sediment shows that the marine sedimentary environ-ment is unstable , and somewhere in the route sea area the hydrodynamic conditions are strong which will lead to a scouring effect on the seabed.More attention should be paid to those obstacles mentioned above in the designation and construction of the submarine cable .