Abstract：Using the numerical simulation by finite element method, the total displacement field change after Three Gorges reservoir impounding was calculated. We found out that there four extreme areas of total displacement appeared as Badong,Niukou,Guizhou and Xintan town after the water level reached 135 m. When water level cuts and tries impoundment to 172 m, the four extreme areas further expanded along the Yangtze river and the values also increased. We contrasted and analyzed the seismic activity and the total displacement field changes after the reservoir impounding to 135 m, and found out that four ML≥2.5 earthquakes occurred in the intersection part of the south section of the Gaoqiao fault and Badong extreme area went with the 135 m water level impounding. 14 ML≥2.5 earthquakes mostly occurred near the Badong and Xintan town total displacement extreme area, after the 172 m water level impounding. The analysis suggests that the gradient zone of total displacement field of the upper crust surface is the active strong shear belt in the vertical direction. It’s also the belt where the vertical shear strain energy is large and the tectonic activity is strong. It’s easy to induce the reservoir earthquake.
Wu Jianchao , Chen Shujun,and Chen Junhua . NUMERICAL SIMULATION OF TOTAL DISPLACEMENT FIELDCHANGE AFTER IMPOUNDMENT OF THREE GORGES RESERVOIR[J]. jgg, 2009, 29(6): 52-55.
