ABSTRACT
To optimize the mechanical properties of prefabricated supporting structures of TBM(Tunnel Boring Machine) tunnel, a TBM tunnel segment with topological interlocking effect is proposed. 1:40 models of a tunnel with 6 m diameter and 13 m length are fabricated, and the bolts are considered in the model. Single-point loading tests simulating the force induced by backfill grouting are conducted. The mechanical properties of conventional and topological interlocking supporting structures are compared. Experimental and simulation results show that, when there are no bolts, the bearing capacity of topological interlocking supporting structure increases by 75.9% than the conventional one; the maximum displacement enlarges by 54.9%. After installing bolts, the bearing capacity of topological interlocking supporting structure increases by 43.4% than the conventional one; the maximum displacement enlarges by 41.7%. At the end of loading, the conventional supporting structure collapses due to the shear failure of bolts, while the topological interlocking supporting structure crushes due to the tensile cracks, either in the center or locally around the bolts. The proposed structure provides us with a new approach to realizing high-performance supporting structures in underground space engineering.
