Restraint effect of partition wall on the tunnel floor heave in layered rock mass

The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass, leading to floor heave in the tunnel. This study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel floors. The results indicate that thin-layered rock mass exhibits weak interlayer bonding, causing rock layers near the surface to buckle and break upwards when subjected to horizontal squeezing. With an increase in the layer thickness, a transition in failure mode occurs from upward buckling to shear failure along the plane, leading to a noticeable reduction in floor heave deformation. The primary cause of significant deformation in floor heave is upward buckling failure. To address this issue, the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock layers. The results demonstrate that the partition wall has a considerable stabilizing effect on the floor, reducing the zone of buckling failure and minimizing floor heave deformation. It is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure stability. Through simulation calculations on an engineering example, it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor.