摘要
位于东非大裂谷的肯尼亚裂谷因其独特的地表地质工程,成为了地球科学研究的热点区。2018年暴雨后,肯尼亚裂谷出露大量地裂缝,对当地基础设施建设造成了严重威胁。为了查明肯尼亚地裂缝的活动特征及形成原因,采取野外调查、工程地质测绘、地球物理勘探、颗粒分析和扫描电镜(SEM)等手段,对地裂缝区域的地质构造背景、地裂缝活动特征以及地裂缝发育区岩土体性质进行研究,探讨了肯尼亚地裂缝的形成过程及多因耦合机制。主要结论为:肯尼亚地裂缝主要发育在肯尼亚裂谷火山隆起区及平原区,调查确定了83条地裂缝,延伸长度与破裂形式相异;地裂缝活动表现为水平拉张运动,少部分具有明显垂直位错,在地裂缝侧壁可见多处小型冲沟;肯尼亚裂谷的断裂活动和火山活动为地裂缝提供了构造基础,在松散的地表沉积物条件下,频繁的暴雨进一步加剧了地表侵蚀,诱发地裂缝地表出露。本文结果不仅可为肯尼亚地区的地裂缝地质灾害防治提供理论依据,也为世界上其他火山活动区地裂缝的研究提供了思路和方向。
The Kenya Rift Valley,located in the East African Rift,has become a hotspot for geoscientific research due to its unique surface geoengineering.After heavy rainfall in 2018,a large number of ground fissures were exposed in the Kenya Rift Valley,posing a serious threat to local infrastructure development.In order to identify the activity characteristics and formation causes of ground fissures in Kenya,field surveys,engineering geological mapping,geophysical exploration,particle analysis,and scanning electron microscopy(SEM)were employed to investigate the geological and tectonic background of the ground fissure region,the activity characteristics of ground fissures,and the nature of rock and soil in the ground fissure development area,as well as to explore the formation process and multi-causal coupling mechanism of ground fissures in Kenya.The main conclusions are that Kenya's ground fissures are mainly developed in the volcanic uplift area and the plain area of the Kenya Rift Valley,and 83 ground fissures were identified in the study,with different extension lengths and rupture forms.The activities of the ground fissures are characterized by horizontal tensile movement,and some of them are characterized by obvious vertical dislocation.A number of small alluvial gullies can be seen in the sidewalls of the ground fissures.The fault activities and volcanism of the Kenya Rift Valley have provided a tectonic foundation for the ground fissures,and the ground fissures can be formed under the condition of loose surface sediments.Under conditions of loose surface sediments,frequent heavy rainfall further exacerbated surface erosion and induced surface outcrops of the ground fissure.The results of this paper not only provide a theoretical basis for the prevention and control of geological hazards of ground fissures in Kenya but also provide ideas and directions for the study of ground fissures in other volcanic areas of the world.
作者
李超
贾智杰
黄伟亮
庄建琦
朱兴华
冷艳秋
马鹏辉
王飞永
彭建兵
LI ChaoJIA Zhijie;HUANG Weiliang;ZHUANG Jianqi;ZHU Xinghua;LENG Yanqiu;MA Penghui;WANG Feiyong;PENG Jianbing(School of Geological Engineering and Surveying,Chang'an University,Xi'an 710054,China;Key Laboratory of Western Mineral Resources and Geological Engineering of Ministry of Education,Chang'an University,Xi'an 710054,China;School of Engineering and Technology,China University of Geosciences(Beijing),Beijing 100081,China)
出处
《工程地质学报》
北大核心
2025年第6期2280-2290,共11页
Journal of Engineering Geology
基金
国家自然科学基金国际(地区)合作与交流项目(资助号:41920104010).
关键词
地裂缝
肯尼亚裂谷
火山活动
降雨冲蚀
成因机制
Ground fissure
Kenya Rift Valley
Volcanic activity
Rainfall erosion
Genesis mechanism
