Yielding device for expansive rock tunnel

The utility model provides a yielding device for an expansive rock tunnel, the yielding device comprises a plurality of anchor rod type yielding pieces arranged below a bottom plate of the tunnel in the radial direction of the tunnel, each yielding piece comprises a telescopic sleeve, a plurality of supporting rods and a plurality of elastic components, the supporting rods and the elastic components are arranged in the sleeve, the sleeve defines the boundary of the yielding pieces, and the elastic components are arranged in the sleeve. The multiple supporting rods are arranged in the radial direction of the sleeve, the tail end of each supporting rod is connected to the inner wall of the sleeve through an elastic component, and the elastic components provide the yielding length to allow the sleeve to contract in the radial direction of the sleeve. According to the yielding device, adaptive yielding to expansive force and stable anchoring and supporting to expansive rock are achieved through structural deforma