The CSIRO overcoring stress relief and hydraulic fracturing methods are the most popular methods used for the measurement of in-situ stress at depth. One major advantage of the CSIRO overcoring stress relief method is that the three dimensional state of stress can be obtained, but the measurement must be done in an excavated tunnel(Hudson and Harrison, 2000). Hydraulic fracturing method can be carried out on the ground surface, but it assumed that one of the principal stresses direction is vertical(Cai et al, 2006). In terms of the disadvantages of the two methods, the techniques based on core orientation and acoustic emission behavior of rocks are incorporated in the in-situ stress measurement in order to obtain the in-situ stress conditions at depth in Shuichang Iron Mine. According to the comparison of the measurement data obtained from the acoustic emission test in the laboratory and CSIRO overcoring stress relief measurement in the field, effectiveness of the acoustic emission test is confirmed. In addition, the relationships between in-situ stresses and tectonic settings are analyzed. Finally, the distribution of in-situ stresses in Shuichang Iron Mine is given, which provides a meaningful guideline for the following mining and design.
So far the slope of Shuichang Iron Mine is the highest one of open pit in China. The slope was designed to be 660m high, and Shougang Group planed to extend exploiting range with the constant and substantial increasing of the iron ore's price. The modified deep of the pit will arrive to 750m at the elevation of −440 m. The stress states, engineering geological conditions and hydrogeology conditions will be different form current environment. So the exploration should be carried out to obtain the factors which are effective on the stability of slopes before the expanded mining.
