Abstract:

A back analysis for tectonic stress field in dam site of hydropower project is implemented by using three-dimensional FEM base on locale investigation and stress testing.It can be find out the reasonable numerical values and direction of boundary loads by contrasting the principal stresses between calculation and tested in-situ at the points for stress fitting by means of applying boundary loads with a different values and directions to three-dimensional model. The results from back analysis are regarded as the value and the direction of tectonic stress field in this region. The results show that the major principal stress σ₁ is 6-7 MPa and its direction is S50°-60°E and minor principal stress σ₃ is 3-4 MPa in direction of N50°-60°E in dam site of hydropower station.

Key words: engineering geology, hydropower project, tectonic stress field, three-dimensional FEM, back analysis