Method for detecting damage to a deck of a bridge

A method for detecting damage to a deck of a bridge, comprising:

• a member detection step for, based on a thermal infrared video of a surface of pavement that has temperature distribution generated by spontaneous heating due to sunlight captured from the surface side of the pavement, detecting structural members of a deck positioned on a rear surface side of the pavement to support the pavement;
• a residence-of-water detection step for, based on a temperature distribution pattern appearing on the surface of the pavement in association with the detected structural members of the deck, detecting residence of water inside the deck or on the surface of the deck;
• and
• a damage detection step for, based on detected residence of water, detecting damage to the structural members of the deck, wherein
• the deck is a steel-plate deck having a steel-made deck plate for supporting the rear surface of the pavement, and steel-made troughs fixed on a lower side of the deck plate,
• the member detection step is to detect joint portions between the deck plate and the troughs based on a thermal infrared video of the surface of the pavement captured from the vehicle running on the pavement,
• the residence-of-water detection step is to detect, out of regions between neighboring ones of the detected joint portions of the deck plate and the troughs, a region having a temperature difference from the other regions as a region where residence of water has occurred, and
• wherein the damage detection step is to detect occurrence of a through crack at a portion of the deck plate corresponding to the region where residence of water has occurred.