Seismic performance of bridges with ECC-reinforced piers

Engineered cementitious composite (ECC) material, which is characterized by satisfactory resilience, moderate energy dissipation capacity as well as superhigh compressive and tensile strengths, has been widely applied to civil infrastructures (e.g., bridges, buildings, and coastal structures). To identify sensitive parameters, enhance resilience, and reduce cost of the ECC-reinforced structures effectively, a sensitivity analysis framework for the ECC-reinforced structures is necessary. In this regard, a uniaxial material model for the ECC material is firstly introduced and implemented in an open system for earthquake engineering simulation platform (OpenSees). A sensitivity analysis approach for the ECC material is proposed by deriving a series of sensitivity analysis equations at structure, element, and material levels based on direct differentiation method (DDM). The sensitivity analysis approach is integrated into the OpenSees and could be used directly for the ECC-reinforced structures. At last, the proposed ECC constitutive model are validated by three benchmark examples. The performance assessment and sensitivity analysis are conducted on a prototype bridge. The analyses results indicate that: (1) the earthquake-resistant and damage-control capacities of the ECC material are better than those of the normal concrete; (2) the DDM-based sensitivity analysis method is more efficient and accurate than the FDM-based one.