Beam bridge longitudinal damage diagnosis based on strain curve intersection point

The invention relates to the technical field of beam bridge quality detection, and particularly discloses a beam bridge longitudinal damage diagnosis method based on strain curve intersection points, which comprises the following steps: testing section strain influence lines at different spans of a to-be-detected beam bridge longitudinal beam N; calculating section damage-free strain influence lines at different spans of the longitudinal beam N; and comparing the position changes of the intersection point NL/n-L/m of the strain influence line at the L/n section and the strain influence line at the L/m section on the longitudinal beam N and the intersection point NL/n-L/m of the strain influence line of the test section and the corresponding zero-damage strain influence line, and identifying the longitudinal damage of the beam bridge. In the longitudinal damage diagnosis of the beam bridge based on the strain curve intersection points, the longitudinal damage of the beam bridge is identified through the strain