DYNAMIC SIMULATION OF STRESS AND DISPLACEMENT FIELDS FOR TSINGHAI-TIBET PLATEAU LITHOSPHERE

摘要

Tsinghai-Tibet Plateau becomes an important research topic of global tectonics, because of its marvelous thickness and rapid uplifting since Quaternary. By using finite element method, the numerical simulation is carried out for the movement of structural lithosphere. The deformable elements are employed to simulate structural zones, and the frictional mechanism is introduced to illustrate the characteristic of a zone with a contact crack surface. The boundary conditions are prescribed by the displacements around the plateau. As a result, the stress and displacement distributions are obtained, which are consistent with P axial orientations of the earthquake focus mechanism and the measured principal stress direction. Analysis and estimate are also made for the evolution of historical process and present situation of the plateau lithosphere.