Study On The Construction Of 3D Geological Model In Nanchang City

The urban geological survey can find out the geological conditions and the features of resource endowment of underground space in city,so it plays an essential role in the expanding of urban spatial form,the economic developmenthe and the construction planning of city.On the basis of Multi-element geological survey project of Nanchang-geophysical subproject NJZX-W-2019-106,the paper begins the study.The research area is located in the Yangtze plate and the south Jiangnan uplift,which have three tectonic zones(JiulingZhanggong mountain uplift,Pingxiang-Leping depression belt,Guanmao mountain uplift).On the consideration of the complex structure and multiple splitting basins in research area,so here begins the research on 3D geological model construction of Nanchang in order to detect the city's geological structure.As we all know,the simplex urban geological research cannot meet the need of the development of society.By collecting the information of research area,the paper does a comprehensive and exact analysis and conclusion of the research area's stratum and geology features,the Red bed's underlayer structure,the hydrogeology's structure and engineering geology's structure,which is meaningful to the Multi-element geological survey project of Nanchang.Then through analyzing the density of each research area and magnetic susceptibility characteristics,provides principles and evidences for identifying the target geographical body of 3D geological model.On the basis of the information,does the inverse calculation of gravity conditioned with prior information and gridding magnetic navigation data to establish the 3D data volume of gravity and magnetism and then get the density 3D model and magnetic susceptibility 3D model.The paper,through 3D derivatives of gravity anomaly and Euler 3D deconvolution technique,recognizes and depicts the structure of research area,and by wavelet-CEEMDAN filtering technology,does the noise reduction of seismic data,then verifies the veracity of directional derivative of gravity anomaly and Euler3 D deconvolution technique to the division of structure.Through analyzing the basic structural unit in research area by density 3D model and magnetic susceptibility 3D model,then recognize the lithologic character in research area and transform that into 3D geological model,and finally build the tentative mapping based on 3D inversion of gravity and magnetism.In the full use of 3D inverse calculation of gravity and magnetism.Based on previous work,does 2.5-dimensional gravity and nagnetic human-computer interactive inversion of eight sections in order to bulid finer stratum-structural geology model to amend the initial 3D geological model,finaly gey a more authnetic and reliable model.Through comprehensive use of geophysical method,the article can recognize and divide the lithology and structure of research area and then build the 3D model to provide technical support for urban construction planning.