Impact resistant lagging, method for designing impact resistant lagging, and apparatus for testing impact resistant lagging

A steel set assembly comprising:

• a first pair of legs and a second pair of legs, the first pair of legs being spaced from and positioned opposite the second pair of legs;
• first and second beams, the first beam secured to one leg of the first pair of legs and one leg of the second pair of legs, the second beam secured to the other leg of the first pair of legs and the other leg of the second pair of legs;
• a plurality of tie rods, each of the plurality of tie rods extending between the first and second beams;
• and
• a panel assembly secured to the first and second beams, the panel assembly comprising:
• a base having a top surface and a bottom surface, the base defining a plurality of raised portions and a plurality of receiving portions, each of the plurality of receiving portions having a substantially planar surface, each of the plurality of raised portions extending from the respective substantially planar surfaces;
• and
• a plurality of blocks, each of the plurality of blocks having a top surface and a bottom surface, each of the plurality of blocks being secured to the base and positioned in one of the plurality of receiving portions, wherein the base extends between the first and second beams and is secured to the first and second beams, each of the plurality of blocks positioned adjacent to another one of the plurality of blocks, each of the plurality of blocks extending between the first and second beams, the top surface of each block is configured to provide protection from falling rock to a space beneath the first and second beams, wherein the steel set assembly is configured to be placed in an underground mine opening.