Initial rock stress has been measured to provide necessary safety information for the construction and maintenance of an underground structure. While valuable in themselves, no attempts have been made to organize these valuable but scattered data into a database-like form.
    Here we reexamined the published data from 75 papers in 15 journals to extract the reported value including the information of depth, rock type, etc. at measuring points, and recalculate critical values on initial rock stress such as three-dimensional principal stress, its direction cosines and six stress components with a viewpoint as the database.
    We also investigated the relations between the depth and the initial rock stress, the elevation and the initial rock stress, the rock classifi cation and the initial rock stress, etc., for each of the three rock types (sedimentary, igneous and metamorphic).