As a fundamental study for support design of underground space using cable bolt, a series of laboratory pull-out tests were conducted. In the test, two types of cable bolts, namely plane strand cable bolt and bulb strand cable bolt, were used. The embedment lengths of cable bolts were 350mm and 4000mm. Then the mechanical behavior of cable bolts in the pull-out tests was analyzed, focusing axial force and axial displacement of cable bolt, confining pressure from surrounding rock, inner pressure acting on the boundary between cable bolt and grout.
The mechanical behavior is dependent on not only type of cable bolt but also Young's modulus of surrounding rock. Both cable bolts are ineffective to increase pull-out load in the case of soft rock and effective in the case of hard rock. Because that the confining pressure from surrounding rock to cable bolt in the case hard rock is stronger than that in the case of soft rock.
