STRESS MEASUREMENTS AND STUDY OF STABILITY OF THE DAMAO TUNNEL

The results of stress measurements carried out in the Damao tunnel in Hainan Province indicate that predominantly horizontal maximum compressive stress of no great magnitude trends NWW,which agrees with that of the major compressive faults in the area and focal mechanism solution. The results of a triaxial test of the strength of the granite into which the tunnel is excavated are also given. Finally the safety measures during excavation as well as the stability of tunnel are disscussed.