Abstract:On the basis of the geological structure, 3D velocity structure and seismic activity in the Yunnan area a 3D finite element model is established. for simulating the presentday annual change characteristics of tectonic stressstrain fields in Yunnan area. The results indicate that: 1) The crustal movements in the north and west of the area are stronger than that in the south and east, also the Yunnan area is characterized by clockwise rotation around the eastern Himalayan syntaxis. 2) Because of the subduction of the India plate, the directions of the crustal movement are as follows: in the east of Red river fault, it’s from SEE in the north to SE in the south, while in the west it’s SE-NS-SW. 3)The maximum principal strain shows the pattern of higher value in the west and north but lower in the east and south, also the maximum value reaches 10 -8, it’s mainly on the western Yunnan area, both sides of the Anning river fault and the north segment of Xiaojiang fault. 4)The maximum principal stress are mostly located along the faults zones and their intersections, the distribution of the maximum differential stress accords with it.In addition, in the south of Yunnan area the differential stress is high, and is tensile, while that is mostly compressive in the other place.
Li Yujiang ,Chen Lianwang ,and Li Hong . NUMERICAL SIMULATION OF ANNUAL CHANGE CHARACTERISTICS OF TECTONIC STRESS-STRAIN FIELD IN YUNNAN AREA[J]. jgg, 2009, 29(2): 13-18.