Study on Formation Mechanism of Zonal Disintegration of Surrounding Rock in Deep Tunnel

With the construction of underground rock engineering, surrounding in deep tunnels appears zonal disintegration fracture and intact zones alternate distribution, which is a special engineering geological phenomenon. This study establishes partitioned model under coupling high in-situ stress osmotic pressure, identify key influencing factors model. Furthermore, intensity factor (SIF) initial cracks on elastoplastic boundary derived using transformation complex functions. Considering seepage pressure rocks, initiation criterion established combined with analysis redistributed fields. Finally, obtained embedded into an extended finite element method (XFEM) platform for numerical simulation. Taking maximum circumferential tensile as cracking criterion, propagation trajectory traced by contour methods. Calculation results have realized modelling whole process crack initiation, propagation, formation. And has be verified.