Techniques for in-situ stress measurement at great depth

Reliable information of in-situ stress state is necessary for the design and construction of most important rock projects. As most rock projects are getting deeper and deeper, traditional techniques of in-situ stress measurement are not very suitable. The current techniques of in-situ stress measurement and their insufficiency for use at great depth are analyzed. Some basic ideas of the development of new techniques and the improvement of current techniques for use at great depth are provided.