A FRACTAL MODEL FOR THE MICRO–MACRO INTERACTIONS ON TUNNEL LEAKAGE

The complex microstructure of the surrounding porous rock of a tunnel has a significant influence on tunnel leakage. However, traditional tunnel leakage models are rarely able to quantify the interactions between the microstructure and macroscopic parameters of the surrounding porous rock of a tunnel, and the influence of the microstructure evolution on tunnel leakage. In order to quantify the contribution of the surrounding rock microstructure to leakage, a model capable of investigating the interaction between the evolution of microstructure and tunnel leakage behavior under the action of multi-physical fields is established based on fractal theory. The model couples the evolution of microstructure with the stress effect, adsorption–desorption effect, water pressure effect and surrounding rock deformation during tunnel leakage. The accuracy of the model is verified against experimental results, and the contribution of the surrounding porous rock pore size and pore distribution to tunnel water leakage is investigated. This study provides a theoretical basis and technical guidance for a reasonably accurate study of the tunnel leakage mechanism.