Abstract: A calculation method of limit load, deformation and energy dissipating of a ring net panel of a flexible protection net, includes step (1): determining geometrical parameters of the ring net, connection type of steel rings, and diameter of steel wires; step (2): determining a loading rate, a loaded region and a boundary condition of the ring net panel; step (3): obtaining basic mechanical parameters of materials through tests, and establishing a critical damage criterion of the ring net panel; step (4): establishing an equivalent calculation model of a ring net panel based on a fiber-spring unit; and step (5): calculating a puncturing displacement, a puncturing load and energy dissipating of the ring net panel. The method adopts a calculation assumption of load path equivalence.

Abstract: A two-stage energy dissipation type shed tunnel support structure connected by a principle of Dougong and a design method thereof are provided. The two-stage energy dissipation type shed tunnel support structure includes a Dougong joint domain, crossbeams and columns. The Dougong joint domain includes section steel members, wavy-wall cylindrical elastoplastic buffers, U-shaped sliding connecting troughs and high-strength bolts. Multiple layers of the section steel members are orthogonally stacked to form a Dougong shape, the wavy-wall cylindrical elastoplastic buffers are arranged between adjacent layers of the section steel members, and the U-shaped sliding connecting troughs are arranged at upper and lower ends of the wavy-wall cylindrical elastoplastic buffers, which realizes a connection between the wavy-wall cylindrical elastoplastic buffers and a section steel in two orthogonal directions.