A STUDY OF COLLAPSE SUSCEPTIBILITY AND RESISTANCE OF LOADED CABLE-SUPPORTED PIPE STRUCTURE SUBJECT TO A SUDDEN BREAK OF CABLE MEMBER

Abstract

Cable-supported pipe system (CSPS) provides a suitable system of structure for meeting the stringent structural requirements of pipeline bridges. However, due to a composite action of cable with truss and pipe members, the sudden failure of its structural member may lead to undesired vibratory response and collapse. The occurrence of a sudden break of the CSPS structural member is characterized by spontaneous dynamics and internal force rearrangement. The present study aims to investigate parametrically the collapse susceptibility and resistance of scaled down CSPS model in the event of a sudden break of the cable member by combined experimental and numerical procedures. The displacement of the structure, the pattern of internal force rearrangement, and dynamic responses were comparatively evaluated. Experimental results depict imminent cable failure under load and attendant dynamic response, but without a total collapse of the CSPS structure. Critical members causing large dynamic response amplitudes were identified and the mitigation of collapse was evaluated. Dynamic increasing factor (DIF) methods was utilized for the evaluation of the dynamic response of the sudden cable break resulting from the pattern of responses between the cable members and the rest of the CSPS structure. Comparison with provisions in other studies shows higher values DIF of the CSPS cable members which led to proposed evaluation using dynamic factor (DF). Thus, the dynamic factors for the sudden break of various cable members along the span and the errors were also estimated considering the parametric of design variables which will enable easy utilization during the structural process of CSPS.