Abstract: The in-situ stress measurement by hydrofracturing method in hydraulic engineering is expounded. In order to obtain scientific and objective test records, and to further analyze the test results, the relation and regularity between geostress respectively with wave velocity in rock mass, seepage flow velocity, and V-shape valley are analyzed on the basis of test diagrams in many practical engineering examples. The recorded stress is closely related with flow velocity during the test. Geostress distribution and direction are affected by tunnel diameter, size and characteristics of the V-shape valley. Moreover, in a macro sense, the geostress value have certain regularity with wave velocity. Last, some issues in the hydrofracturing test method are discussed.

Key words: hydrofracturing method, stress distribution, V-shape valley, wave velocity, questions and discussion