Effects of Tectonic Stress on Stability of Dilatancy Characteristic Soft Rock Roadway Intersection in Deep Underground

Dilatancy characteristic and tectonic stress are two important influencing factors on surrounding rock stability of soft rock roadway and intersection in deep underground. First, mechanical properties of dilatancy characteristic soft rock were studied. On the basis of outcomes of latest theory research, the direct formula about the relationship between the dilatancy angle and surrounding rock deformation was deduced. Then, using numerical methods, the volumetric dilatation of soft rocks around roadway was analyzed. The results showed that surrounding rock deformation and volumetric strain around soft rock roadway all changed nonlinearly increasingly with the increase of dilatancy angle. The larger dilatancy angle was, the greater confining pressure became, the greater supporting force was required, and the worse surrounding rock conditions became. Furthermore, effects of tectonic stress on the law of surrounding rock deformation of dilatancy characteristic soft rock roadway intersections in deep underground were studied. The results show that in the tectonic stress field and deep underground, surrounding rock of dilatancy characteristic soft rock intersection would show large deformation, large loose scope and partial expansion characteristics, whose location and size regularly changed with maximum horizontal stress direction.