Experimental Analysis of Rock Boulder Impacts on Brick Walls to Support Numerical Modelling of Building Damage

Abstract

To estimate the expected damage due to rockfalls and debris flows for buildings and people, it is essential to assess the response of brick walls to boulder impacts. There are scarce physical tests of the impact of boulders on brick walls, which are typical of residential buildings. A simple and low-cost experimental setup for investigating the damage of unreinforced brick walls that are subjected to a boulder’s impact is presented. The setup consists of a ramp that is adjusted with a light steel structure. Seven pilot tests for five single-leaf brick walls of a 1000 × 1000 mm2 area, hit by a 72.925 kg granite boulder, and from five release heights (0.25 m, 0.50, 1.00 m, 2.50 m, and 3.00 m) are performed. The observed damage indicates that wall breakthrough occurs for translational kinetic energies as low as 500 J. The prevalent failure mechanism is local shear damage. Additionally, a numerical model to simulate the physical tests was developed using the FEM. Using the same properties as in the physical testing, the numerical model is found to realistically reproduce the displacement of a node at the centre of the impact, as well as the translational impact velocity and energy, for the same five boulder release heights.