Behaviour of Steel-Concrete Composite (SCC) girder under impact due to rock fall

Abstract

This paper presents a comprehensive numerical investigation on static and dynamic behaviour of the steel-concrete-composite (SCC) girders. Finite element model of steel concrete composite girder under quasi static loads is generated and the responses are validated with the experimental results conducted by the first author. Subsequently, the FE model is adopted to predict the dynamic behaviour of the SCC girder due to rock fall. In order to understand the significance of the studs in SCC girder and their behaviour under impact loading due to rock fall, in this regard two cases are demonstrated. First case is to understand the behaviour of SCC girders without any shear connection and, second is with full shear connection. All the numerical investigations are carried out using commercially available nonlinear explicit finite element code ABAQUS. During finite element analysis the attention has been paid to appropriately model the symmetry boundary conditions, and material behaviour for both steel and concrete. The well suited concrete damage plasticity model is adopted and input parameters are provided based on the standard laboratory tests. Present numerical model could closely predict the flexural capacities for three SCC girders having various stud spacing's. The progressive movement of plastic zone in the steel beam section has been found with the increased loading. This indicates maximum utilization of steel beam capacity as the neutral axis lies near top flange. Failure mode of the composite girder under rock fall event have also been predicted which may be helpful in the design of a protective strategy.