| Jianou City is located in the northern part of Fujian Province.The area has complex geomorphological types,peaks,mountains,hills,valleys and valleys.The overall topography is high in the east and low in the west,and the terrain is highly variable,with complex geological conditions.The thickness of the weathered soil layer is large.In recent years,with global warming,sudden and local extreme rainfall events have occurred in Jianou City,and mountainous areas are often disturbed by typhoons and local short-time abnormal heavy rainfall,coupled with frequent human socio-economic activities in the process of urbanization,it is more common for mountainous township residents to cut slopes to build houses,resulting in a large number of geological hazards events.Jianou City is one of the counties and cities in northern Fujian that are seriously affected by geological hazards.Geological hazards are characterized by a large number of points,a wide range of areas and a great danger,and there is a growing trend of aggravation,which directly affects the development of the economy and all aspects of people’s lives.Therefore,it is of great theoretical and practical significance to carry out research on geological hazards to protect people’s life and property,reduce the loss of geological hazards,and achieve sustainable social and economic development.The main work carried out in the thesis and the main results achieved are.(1)Based on the detailed investigation of geological hazards in 18 townships(streets)of Jianou City,the geological environment conditions of Jianou City were analyzed and the types of geological hazards in Jianou City were concluded to include landslides,landslides,unstable slopes and mudslides.(2)The development charectaristics,formation of conditionnal and influence factors of various types of geological hazards in Jianou City were analyzed,among which small shallow soil landslides in front of houses are the main ones,while landslides,landslides,unstable slopes and mudslides are mainly controlled by the lithology of strata,geomorphology,geological structure and groundwater action,and rainfall and human engineering activities are the main external factors that induce geological hazards.(3)To classify and evaluate 126 different types of geological hazards in Jianou City,75 hazards with poor stability,accounting for 59% of the total number of hazards,49 hazards with poor stability,accounting for 39% of the total number of hazards,and only 2 hazards with good stability,accounting for 2% of the total number of hazards.(4)A typical geological hazards site in Jianou City-Nanze geological hazards site(landslide)in Nanyuan Village,Dongfeng Town-was analyzed by causes,a landslide deformation damage model was established,and stability calculations were made for the landslide body.Targeted comprehensive engineering management measures such as slope cutting and load reduction,retaining wall,anchor lattice and drainage were proposed.(5)Combined with the actual situation of Jianou City,the types and characteristics of geological hazards,the prevention and control plans such as monitoring and early warning,relocation and avoidance,engineering management and restrictive measures were proposed for the disaster mechanism of geological hazards in the study area. |
