Numerical Modeling of Buried Steel Pipe Subjected to Impact Load

Abstract

Rockfall is an extremely rapid process involving long travel distances, so the vulnerability of buildings and infrastructure is quite likely. This paper aims to simulate the response of steel buried pipe subjected to impact load using a numerical approach based on a finite-element method. The verification of the numerical model was performed based on an experimental study, and then a series of parametric analyses was performed to evaluate the effect of some contributory factors, including pipe burial depth, drop height, radius of impact area, and soil damping, on the response of buried pipes. The results showed that with increasing burial depth, there was a significant decrease in the magnitude of through-wall bending stress and vertical deflection of the pipe, but at burial depths greater than three times the pipe diameter, the rate of this reduction decreases considerably. Also, as the impact radius increases, the vertical deformation of the pipe and the stress in the pipe wall increase. Moreover, it was found that the impact load in shallow buried pipe (h/D=1) gave rise to stress concentration and ring deflection. It is strongly suggested that the selected burial depth of pipe be larger than both 1Dp and 0.08H.