Deterioration of reinforced concrete pipes is checked and the
deterioration progress level is classified. Based on the inspection
result, a portion to be inspected in detail in an inspection area is
selected. With respect to the selected portion to be inspected in detail,
the pipe thickness and the diameter of reinforcing bars are measured and
the location of reinforcing bars in the portion to be inspected in detail
are checked. Using the data of the thickness of a pipe, the diameter of
the reinforcing bar and disposition of the reinforcing bars, structural
analysis is carried out and the strength of the reinforced concrete pipe
is calculated. The calculation result is used as information for
evaluating the deterioration state of the reinforced concrete pipe.