A Study Of Modern Movement Of The Earth Crust On Groundwater In Fractured Rocks

The bedrock area accounts for half of the land surface on the earth and three quaters of China.Groundwater circulation and distribution in bedrock areas are mainly controlled by faults,especially those formed by neotectonics.It is of great significance for the development and utilization of groundwater resources and the prevention and control of ground water disasters in the bedrock areas to study the mechanism and distribution of faults and fractures.Very little is known regarding the mechanism and distribution of water-conducting faults by neotectonics which are important and unsolved scientific problems in hydrogeology.First,on the basis of reviewing and summarizing the research on groundwater in fractured rocks,the velocity field of continental crust movement in China in recent years was analyzed and the effect of the plate tectonic movement on groundwater in bedrocks was put forward.It was pointed out that the difference in velocity of the crustal movement in the eastern China is about 290 °.A new explanation was provided for the formation of active fractures and the formation of groundwater in the fratures based on the GPS observation crustal movement.The results of this study help to improve our understanding of the formation and circulation of groundwater in fractured bedrocks,to develop a new theory of tectonic control,and to guide future hydrogeologic practice and the prevention and control of groundwater disaster in the bedrock areas.Second,this thesis studied the relationship between the faults on the ancient city wall of Nanjing and its recent crustal movement,and simulated the formation of the fractures of the wall.The Nanjing city wall is one of the oldest and largest human structures in China.After more than 600 years of vicissitudes,it has not only carved the mark of human activities,but also left traces of natural processes,especially the fractures which are the best targets for studying the recent crustal movement.A throughout field survey of the fractures on the wall was carried out.It was found that the fractures were related to the geological activities of East China,and the neotectonic movement may play a control role in their formation.These fractures and faults may control the regional and local groundwater circulation and affect the long-term stability of buildings,bridges,tunnels,and highways.This thesis also studied the relationship between the rupture of the city wall and the crustal movement,and explained the hydrogeological and engineering geological significance of these fractures using the electric method and the high density electrical method to identify the new tectonic faults and verifies the hydraulic conductivity of the fractures through drilling.The results of this thesis may help to guide groundwater exploration as well as hydrogeologic practice in bedrock areas.