Independent tension system design and pre-stress uniformity analysis for steel bars of high-speed rail track slab

Aiming at the issues of non-uniform pre-stress on steel bars in Chinese Rail Track System III (CRTS III) track slabs under traditional beam-based tension system, as well as the low accuracy of tension process simulation, this paper first analyzed the mechanism of pre-stress deviation caused by beam deformation. Subsequently, a novel independent tension system was proposed, in which the tension plates were driven by a hydraulic system to independently apply pre-stress to each steel bar. Furthermore, based on the accurate mechanical structure and hydraulic system models for both the beam-based and independent tension systems, mechanical-hydraulic co-simulation models were established in NX Simcenter 3D module. Based on the co-simulation models, the pre-stress distribution characteristics of steel bars in P5600 track slab under independent and beam-based tension systems were compared. The pre-stress fluctuated seriously in beam-based tension system and the ratios of the maximum pre-stress deviation on transverse and longitudinal steel bars to the target pre-stress were 16.03% and 8.21%, while the ratios reduced to 3.61% and 2.22% in independent tension system. Finally, an independent tension experimental testing system was established and the accuracy of the mechanical-hydraulic co-simulation analysis and the effectiveness of the proposed independent tension system in improving the pre-stress distribution uniformity were verified.