Application of hydraulic fracturing in-situ stress measurements in tunneling along the Dali-Lijiang Railway, Yunnan, China

Hydraulic fracturing in-situ stress measurements have been applied in the engineering region of the Dali-Lijiang Railway. This method has determined the present stress state of the earth's crust, i.e. the magnitude and direction of the in situ stress, in the tunnel wall rocks in the engineering region. According to the distribution features of the insitu stress, the paper analyzes the possibility of rock burst during the excavation of the tunnel. The analytic results of the measuring data may serve as the scientific basis for the lining design, section choice and axis azimuth definition of the tunnel.