Patent ID: 7393060

Claim:
A method of protecting a mining structure, comprising: fastening a grid to a wall or roof of said mining structure, the grid including: first and second groups of parallel, load-bearing strands, wherein the strands of the first group extend in a longitudinal direction of the grid and the strands of the second group extend transversely to the longitudinal direction of the grid and the strands of both groups are joined together at their points of intersection, alternating first portions and second portions disposed adjacently with respect to one another and extending at least in the direction of the strands of one of the two groups, wherein the strands of one of the two groups have a large spacing in the first portions between the strands and a small spacing in the second portions between the strands, said large spacing being larger in extent than said small spacing, wherein said large spacing is repeated substantially throughout said first portions and said small spacing is repeated substantially throughout said second portions, wherein a tensile strength of each of said second portions is higher than a tensile strength of each of said first portions, and wherein said second portions are fastened to said wall or roof of said mining structure.