Beam reinforcing structure

A beam reinforcing structure in which beam reinforcing metallic materials are connected to the beam, comprising:

• a beam being an H-shaped metallic material having a web part, flange parts that are above and below the web part, and a through hole formed on the web part;
• a ring-shaped first ring beam reinforcing metallic material that is fixed on the periphery or an edge part of the through hole;
• and
• a pair of second beam reinforcing metallic materials that are fixed in the vicinity of each of the flange parts of the beam that are above and under the first ring beam reinforcing metallic material, wherein:
• both of the second beam reinforcing metallic material having a three-dimensional shape with a longitudinal direction comprise:
• a contacting surface that contacts the web part of the beam;
• a welding surface that is welded to the web part;
• and
• a counter-flange-part surface that faces the flange part of the beam,
• the cross-sectional area of a center part in the longitudinal direction thereof is larger than each cross-sectional area of both end parts of the second beam reinforcing metallic material in the longitudinal direction thereof,
• a protrusion that shows the direction of the counter-flange-part surface extends from a side surface of the counter-flange part surface thereof, and
• a welding-range specifying part that specifies a range of welding is formed on the welding surface, and the welding-range specifying part of the welding surface is welded to the web part.