TUNNEL SIDE WALL SUPPORT DESIGN METHOD BASED ON WEAK PLANE SHEAR SUPPORT THEORY

摘要

Disclosed is a tunnel side wall support design method based on a weak plane shear support theory. The tunnel side wall support design method comprises the following steps: building a force balance mechanical model for a slip failure of a rock mass around a half coal and rock tunnel along a certain weak plane α under the action of an external force; judging a critical condition at which a shear failure occurs on surrounding rocks on a half coal and rock tunnel side wall; determining that the shear strength on an inner side of the tunnel in a direction of 45° is maximum; building a support mechanical model for the half coal and rock tunnel side wall based on the shear strength principle that the rock mass needs to be pressed against the largest shearing weak plane on the largest shearing block after being reinforced and supported by anchor rods; and providing a calculation formula for the number n of the anchor rods on the weak planes on the tunnel side and a length l_i of the i-th anchor rod in order to design the tunnel side wall support. By means of the method, support materials are reduced, the support cost is reduced, and a beneficial reference is provided for the scientific performance and applicability of support parameters.