南海北部外陆架和上陆坡海底滑坡稳定性研究
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摘要
海洋工程地质调查发现，在南海北部外陆架和上陆坡海底，有大片滑坡，其水深范围约在１８０—６５０ｍ之间，它们沿着陆架外缘坡折处呈北东—南西方向分布，其具体位置往往与古三角洲前缘的海底陡坎及古海岸线位置密切相关，大量浅层地震、旁侧声纳、底质取样分析和土体力学理论计算表明，本区滑坡主要是由于地形坡度、沉积物特性、土体自身重力、海底底层流速的大小等诱发因素而产生，而且有些滑坡带还具有多期滑动的性质，它们是区内海底很不稳定的地带，是一种重要的地质灾害因素，在海洋工程地质设计和实施时要引起注意。
It can be found that there is a stretch of landslide on the seafloor of outer continer- tal shelf and upper continental slope in the northern South China Sea by marine engi- neering geological investigation,The water depth is between 180 and 650m,The land- slide lies along the slope break at the outer edge of the continental shelf in NE-SW direc- tion,Its exact location is always interrelated closely with some seafloor scarp and ancient coast line at an ancient deltaic front.It is showed by shallow seismic profile,side scan sonar,bottom material sampling analysis and soil mechanical theory, that the inducing factors of landslide are landform slope,sediment characteristics,soil body gravity and bottom current speed and so on,Some areas even see multiple slidings。Thus we can say that the landslide areas are very unstable and can cause great geological hazard.Atten- tion should be paid to the landslide when carrying out marine engineering geological con- struction in the seafloor.
It can be found that there is a stretch of landslide on the seafloor of outer continer- tal shelf and upper continental slope in the northern South China Sea by marine engi- neering geological investigation,The water depth is between 180 and 650m,The land- slide lies along the slope break at the outer edge of the continental shelf in NE-SW direc- tion,Its exact location is always interrelated closely with some seafloor scarp and ancient coast line at an ancient deltaic front.It is showed by shallow seismic profile,side scan sonar,bottom material sampling analysis and soil mechanical theory, that the inducing factors of landslide are landform slope,sediment characteristics,soil body gravity and bottom current speed and so on,Some areas even see multiple slidings。Thus we can say that the landslide areas are very unstable and can cause great geological hazard.Atten- tion should be paid to the landslide when carrying out marine engineering geological con- struction in the seafloor.
引文
1林振宏，杨作升编．海岸河口区重力再沉积和底坡的不稳定性．北京：海洋出版社。1990．2寇养琦．南海北部的海底滑坡，海洋与海岸带开发，1990，7（3）：48－51．3牟会宠等编．滑坡．北京：地震出版社，1987．4冯文科等．南海北部晚第四纪地质环境。1988．P．595业治铮，汪品先．南海晚第四纪古海洋学研究．青岛海洋大学出版社，1992．6郭安宁．海底地震滑坡－浊流对工程的危害评价及对策．海洋开发工程技术论文集（下）。1987，754－758．7唐大雄，孙愫文．工程岩大学．北京：地质出版社，1985．8DenysBrunsdenandD．B．Prior，SlopeInstability．1984，176．
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