ABSTRACT
A borehole was drilled in granodiorite rockmass at Fangsan, Beijing, China. The depth of the borehole is 301 m with diameter of 110 mm. From about 30 m to 301 m, all cores were oriented. AE Kaiser effect tests on oriented core at depth of 270 m and 294 m were carried out. AE Kaiser effect tests estimated the vertical principal stress are 7.4 MPa and 7.7 MPa. The lithostatic pressure at the depth of 270 m and 294 m in granodiorite rockmass is 7.3 MPa and 7.9 MPa. Both of them are almost same. In horizontal plane, for four directions rock specimen, AE Kaiser effect tests were carried out and corresponding normal stress were gotten. The horizontal larger and smaller principal stress are 21.2 MPa and 12.1 MPa at depth of 270 m and 21.8 MPa and 12.2 MPa at depth of 294 m successively. The orientation of horizontal larger principal stress is about the NS. Comparing the result of AE Kaiser effect tests with hydrofracturing shows that they are consistent fundamentally.
