• 责任者：Lu Mingyong (China Center for Earthquake Disaster Emergency and SAR ; Beijing 100049 ; China) ; Zheng Wenheng
• 刊名：Chinese Journal of Geophysics
• 出版年：2010
• 卷期：53(9)
• 关键词：大震 ; great earthquakes ; 唐山地震1976 ; Tangshan earthquake 1976 ; 河北 ; Hebei Province
• 页码：p.2110-2118
• 图表：7 illus., 20 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

The authors use the three-dimensional non-linear dynamic finite element method to perform a modeling study on dynamical stress effects with a rhombic model and analyze the Tangshan M7.8 Earthquake in 1976. The result shows that stress wave is generated by shock force before the Tangshan earthquake, when this wave encounters a fault, the reflected stress wave, becomes tensile due to half-wavelength loss, which causes cracks, local rupture and crack linkage in the rock by reducing rock friction. On the one hand, other earthquakes are triggered. On the other hand, energy for the Tangshan Earthquake is accumulated. This is a process of positive feedback. The shock force from the Tangshan Earthquake during processes of loading and unloading has a time difference, this forms the different phase of shock waves. The dynamical stress produced by stress wave, superposed on the confining pressure, makes confining pressure reduce and change at low values. These effects can reduce shear strength and make the initial fracture of the Tangshan Earthquake propagate toward northeast and southwest respectively.