STUDY ON FLUID-STRUCTURE INTERACTION BASED ON HARD ROCK DETERIORATION THEORY

Based on the fluid-structure interaction theory, FLAC3D was adopted to conduct a numerical simulation on the excavation of hong shigou hard rock tunnel. The basic mechanical properties for rock mass changed significantly during the process of secondary stress adjustments, and the rock deterioration constitutive model (RDM) can accurately reflect both the abruptness of the rock yield failure and the changes of mechanical parameters after yield. On the basis of RDM, the permeability coefficient with equivalent plastic strain function was introduced which can update the permeability coefficient. The results showed that both the surrounding rock displacement and the volume of plastic zone increased significantly because of the seepage action. Therefore, the seepage of fissure water on the hard rock should be fully considered during excavating and supporting in order to prevent accidents such as water inrush and sudden collapse.