Dun-Mi Fault Sinistral Strike-slip Three-dimensional Finite Element Simulation

Study Areas (Jixi Basin, southern of Hulin Basin) is located in China's northeastern region, along the Dun—Mi fault distribution. Dun-Mi fault is one of the Tan-Lu Fault Zone branches, its south begin with Shenyang, pass Fushun, Dunhua and other places. North East was to be extended to the northeast of Mishan close to Hutou ,pass Wusuli river enter Russian territory.Large numbers of geological evidence show of Jixi and the southern part of Hulin Basin at the Early Cretaceous period originally for a unified basin, later Dun-Mi fault sinistral strike-slip formation of the current tectonic pattern. Jixi basion and Hulin basin formed in the Early Cretaceous, the basic consensus has been reached. For Dun-Mi fault formation times, reference to the results of previous studies from Dun-Mi fault might be formation of Jurassic to Early Cretaceous, and in the late especially the Late Cretaceous occurred time after time sinistral strike-slip. Sinistral strike-slip stagger of the basin on both sides of the fault. Liu Zhaojun research the sedimentary facies resume of the eastern basin show that Sanjiang region in the Early Cretaceous Jixi Group sedimentary period of a unification basin. Jixi Basin in Dun-Mi fault Jixi group sedimentary completely disappear, the lack of fringe phase. This proves that the Jixi basin by the Dun-Mi fault l sinistral strike-slip transforming, its eastern basin's sedimentary edge of future should be at the southern part of Hulin basin on present. According to the geophysical information, The north and south of Hulin Basin, the nature of the basement significantly different, Therefore, the current Hulin Basin exist two basins ofthe South and the North. Hulin Basin in southern exist an uplift with the Jixi basin of Hengshan uplift terrain also comparable. Therefore, the author consider that the Jixi Hulin Basin and the southern part of the Hulin basin original is a unification basin, Dun-Mi fault sinistral strike-slip stagger the basin and now moved the location.According to previous research, Dun-Mi fault zone from the south to the north were take turns staggering the margin of the Huabei platform,Xilamulun River-Changchun - Yanji splicing belt,Mudanjiang fault, and Dun-Mi fault stagger the Hubei plate margin of the North border ,Mashang group of Heilongjiang Province, thereout obtain that the Dun-Mi fault zone strike-slip distance in the amount of 136-170km.To further study Dun-Mi fault sinistral strike-slip translation features,based on the existing paper of geological data, using 3D finite element simulation of the tectonic stress field, adopt ANSYS software to the sinistral strike-slip characteristics of Dun-Mi fault with the Tectonic Tectonogeometry numerical simulation. To further confirm Jixi basin and the southern part of Hulin basin is the original basin for a unified basin model to provide reliable evidence.The basic concept of Finite element analysis is using the relatively simple issue of substitute complex problems later solving. It will become the domain of result is discrete finite element as many small Internet-domain composition, on the assumption that each module a suitable approximate solution, and then the domain is derived for the total satisfaction, hence the solution. Because of practical problems to predigest dispose,according to the finite element analysis, the solution is not exact solution, but approximate solutionANSYS is a structure, thermal, fluid,electromagnetic and acoustic of the general-purpose finite element software, can be widely used in the nuclear industry, railways, petrochemical, aerospace, machinery manufacturing, energy, transport vehicles, national defense, electronics, engineering, biomedical, water, daily household appliance and general industrial research.According to resume after the shape of the basin, with a rectangular basin instead of the irregular shape of a simple model, assuming that the original Jixi basin and the southern of Hulin basin with a basin, the basin above that there is a fracture ,Dun-Mi fault, geological model squeezing pressure on the individual bearing, coming along strike-slip faults, make it separate. Right to impose a different size and direction power on the model ,study to the most appropriate size and direction of the pressure that make it separate from squeezing.The model of selection is a single vertical fracture of the block model. Presume model 135km long, 135km wide, the depth of 40km, with a move toward NE45°vertical fault. Materials based on the model to calculate granite. And outside and inside of faults with different physical parameters. Fault of outside elastic modulus is 60000MPa, Poisson's ratio is 0.21μ. Fault within the elastic modulus is 700MPa, Poisson's ratio is 0.17μ. Based on the assumption that the establishment of block geometry model. Coordinates of the origin of the block model for the Northwest bottom corner, the X-axis pointing East, South Z-axis direction, Y-axis direction depthPartition mesh a free mesh, element type modules for SOLID95 entities. After determine the boundary conditions carry through five groups simulation to this model,the same size power were imposed (160MPa) but of differentdirection. The first four groups were north , NNW 10°, NNE 10°,NNW20°above simulation, The 5th Group based on the impetus of Dun-Mi fault sinistral strike-slip came from Izanagi plate subduction.The grater influence period is four subduction, periods.According to the four subduction, periods carry though consecutive simulation to the model.In this paper, a total of five groups simulation, the former four groups are north direction, NNW10°, NNE10°,NNW20°subsection simulation to the model; The 5th Group based on the impetus of Dun-Mi fault sinistral strike-slip came from Izanagi plate subduction The grater influence period is four subduction, north , NNW10°,NNE10°,NNW20°.According to the four subduction, direction carry though consecutive simulation to the model.Based on the five groups Dun-Mi sinistral strike-slip fault simulation of detailed analysis of three-dimensional finite element numerical simulation analysis process, come to the following conclusions :1. According to the four group model simulation of the final by a certain method of calculating cumulative calculated Dun-Mi fault sinistral strike-slip stagger Jixi and the southern part of Hulin Basin distance is 307.75km; by the fifth consecutive simulation models from the results of the Dun-Mi fault sinistral strike-slip stagger Jixi basin and the southern part of Hulin basin distance of 406.8km.2.For Dun-Mi fault sinistral strike-slip distance,of that earlier simulation of the detailed data, the infection factor of the speed running of plate, the role time and angle.And the former table 3 from the equivalent model can be seen the transform distance biggest distance offer is Izanagi plate NNW12°subduction plate,the bigger is Izanagi plate NNE2°subduction,so can enduce thisconclusion:relative to other factors in terms of operational speed plate for strike slip a greater impact. For the adoption of this simulation come to the Dun-Mi fault sinistral strike-slip faults stagger Jixi basin and the southern part of Hulin basin distance is 307.75km and 406.8km. For the two results,there are a lot of infection factors, for example the choice of material model of a single granite attributes definition model material, and the cover model did not consider sediment properties;with the actual situation in these Tan-Lu Fault late dextral strike-slip, Pacific Plate to the west amass and dive has been led to the final outcome of the reasons for discrepancies. The first result is a phased simulation, the second result is a simulation of a continuous process.So the second results is more close to the actual situation. Contrast the Dun-Mi seslip faults in 136-170km, Simulation results is bigger.But most scholars consider that the Tancheng - Lujiang Fault South Africa of the strike-slip displacement between 400-550km North of Dun-Mifault strike-slip displacement should be less than Tancheng - Lujiang Fault . Tan-Lu fault of South Africa began to gradually expand north east, it north of the strike-slip fault displacement should be gradually reduced, But in the simulation process is not considered zone north east of the development process of gradually increasing resistance to the impact of factors, As a result, have the simulation results. But contrast the majority of scholars believe the Tancheng - Lujiang Fault South Africa of the strike-slip displacement between 400-550km.In this paper, the simulation results are basically consistent with reality.