ELASTOPLASTIC SOLUTION OF SURROUNDING ROCK STRUCTURE OF LINING AND BOLT SUPPORT FOR DEEP BURIED CIRCULAR TUNNEL

Based on the Drucker-Prager yield criterion, the elastic-plastic solution of deep buried tunnel with lining-anchor support under different construction stages is derived by using the equivalent material method, and the FLAC3D numerical simulation is verified. The results show that the plastic zone is located inside the lining, and the anchoring effect of the bolt has no obvious response to the expansion of the plastic zone. The plastic zone extends to the anchorage zone, and the anchoring effect of the bolt in soft rock has a good response to the inhibition of plastic expansion. When the plastic zone extends to the anchorage zone, the radius of the plastic zone is negatively correlated with the elastic modulus of the bolt, and the radius of the plastic zone is positively correlated with the supporting angle of the bolt. The anchoring effect of the bolt in soft rock is more obvious to inhibit the expansion of the plastic zone.