Similar model test of a mudstone-interbedded–sandstone-bedding rock tunnel

Abstract

Herein, for the Zhengzhou–Wanzhou high-speed railway mudstone-interbedded–sandstone-bedding rock tunnel, the mechanical parameters of the surrounding rock were tested via uniaxial and triaxial compression tests, and these were converted into rock mass parameters according to the Hoke–Brown theory. Various similar mudstone, sandstone, and tunnel lining materials were prepared in accordance with the similarity theory and orthogonal tests. Based on a similar model test, the effects of the bedding structure and different burial depths on the tunnel lining were simulated. The displacement and contact pressure along the normal direction of the tunnel bedding were evidently greater than those along the tangential direction of the surrounding rock. Further, increasing the burial depth of the bedding tunnel first resulted in longitudinal cracking at the lining invert. Simultaneously, floor heaving occurred in the lining invert, and longitudinal cracks appeared at the lining arch waist corresponding to the normal position of the bedding structure. The similar model test results were found to be in good agreement with the tunnel field test results, indicating that the test model could simulate the mechanical behaviour of bedding rock mass tunnels.