Nonlinear random seismic response analysis of the double-trough aqueduct based on fiber beam element model

As an important lifeline project, large reinforced concrete aqueduct structures sometimes pass through areas with high seismic intensity. Therefore, the aqueduct structure is susceptible to earthquake damage or destruction during the water conveyance process, resulting in interruption of water conveyance and major safety accidents. In fact, because concrete is a multiphase composite material, it has obvious nonlinear and random characteristics. At the same time, seismic excitation is also naturally random due to differences in frequency spectrum and duration. Based on this, this paper uses the concrete elastoplastic random damage constitutive relationship and the random seismic excitation model to carry out the random nonlinear seismic response analysis of the doubletrough aqueduct structure. The thin-walled characteristics of the girder section of the aqueduct structure is significantly different from that of the general bridge structure, and there is a certain error in the simulation of the seismic response of the aqueduct with traditional beam elements. Therefore, this paper combines the refined fiber beam element model, compiles the TCL language program suitable for the OpenSEES open analysis platform, and establishes the refined fiber beam finite element model of the aqueduct structure based on the random damage constitutive relationship of the concrete. The study of the response law and failure mechanism of aqueduct structures considering the coupling of concrete nonlinearity and seismic excitation randomness provides an important theoretical basis for the seismic optimization design of large-scale aqueduct structures.