Abstract: To determine and calculate the geological asymmetrically-pressurized load of inclined-layered surrounding rocks, a drawer model considering the structural characteristics of inclined-layered surrounding rocks is established, and the calculation method for geological asymmetrically-pressurized load coefficient and the criterion of recognizing geological asymmetrically-pressurized load are proposed. Additionally, the influencing factors and laws of geological asymmetrically-pressurized load are analyzed, and the deformation and failure mechanism of the inclined-layered surrounding rocks is examined. The results reveal the following: (1) The internal friction angle of the rock face, tunnel buried depth, and rock layer inclination have a greater influence on the geological asymmetrically-pressurized load of the tunnel lining. The larger the tunnel buried depth and the internal friction angle of the rock face, the smaller the geological asymmetrically-pressurized load of the tunnel lining. (2) The larger the inclination angle of the rock layer, the greater the geological asymmetrically-pressurized load of the tunnel lining. A case study is conducted on a remediation project of tunnel support failure in Muchuan County, validating the effectiveness of the drawer model in describing the geological asymmetrically-pressurized load of inclined-layered surrounding rocks.

Key words: shallow tunnel, layered surrounding rock, drawer model, geological asymmetrically-pressurized load, load calculation method