FINITE ELEMENT MODEL VALIDATION OF PRETENSIONED CONCRETE CROSSTIE BASED ON FIELD INSTRUMENTATION

摘要

As the primary structural component in railroad track, prestressed concrete crossties have been widely applied in North America to accommodate the increase of freight axle load, and the development of high-speed passenger train. However, the design standard of American Railway Engineering and Maintenance-of-Way Association (AREMA) remains unclear about the relationship between wheel load and the flexural demand of prestressed crossties. In this study field experimentation was conducted at the Transportation Technology Center at Pueblo, CO, and the test data was compared with a finite element (FE) model of the track structure for model validation. Embedded strain gauges and potentiometers were installed in the experimentation to measure the response of the concrete crosstie. The FE model consists of two parts: a detailed single-crosstie model to capture the local response of the loaded crosstie, and a global multi-crosstie model to provide realistic boundary conditions for the detailed model. The bond-slip behavior between concrete and prestressing wire, and inelastic material property are incorporated in the FE model. Good agreement is observed between the test measurement and model output. The validated FE model will be used for future parametric studies on the flexural design of concrete crossties.