Method for calculating bending deformation of bridge pier under impact action of landslide debris flow

The invention provides a bridge pier bending deformation calculation method under the impact effect of landslide debris flow, and relates to the technical field of bridge piers. The calculation method comprises the following steps: dividing a bending deformation stage when the pier is impacted by a landslide debris flow into an elastic stage, a plastic stage and a plastic failure stage which appear in sequence; in the plastic failure stage, when pier body concrete of the pier cracks due to impact of landslide debris flow, the cross section of the pier at the crack position is divided into a crack area including the crack and an effective area not including the crack, and the area of the effective area and the section equivalent bending rigidity of the cross section of the pier are calculated; calculating section effective bending rigidity of the cross section of the pier based on the area of the effective region and the section equivalent bending rigidity; and calculating the total transverse displacement of