Durability Assessment Method of Hollow Thin-Walled Bridge Piers under Rockfall Impact Based on Damage Response Surface

Continuous rigid-frame bridges across valleys are often at risk of rockfalls caused by heavy rainfalls, earthquakes, and debris flow in a mountainous environment. Hollow thin-walled bridge piers (HTWBP) exposed to the threat impact from accidental rockfalls. In current research, ANSYS/LS-DYNA is used establish high-precision rockfall-HTWBP model. The model verified against scaled test performed previously published research. A mesh independence also obtain an appropriate size. Based on model, force, damage, dynamic response characteristics HTWBP under rockfall studied. addition, damage assessment criterion proposed, based surface combined with central composite design method Box–Behnken method. main conclusions as follows: (1) force has substantial impulse characteristic, duration load approximately 0.01 s. (2) impacted pier dominated final elliptic conical strip areas symmetry axis. cross-sectional mode compression failure area shear corner. (3) maximum displacement occurs middle height pier. increases height, velocity, diameter decreases uniaxial compressive strength concrete. (4) initial velocity most significant parameters affecting indices. method, zoning diagram established for fast level HTWBP.