Research on Stresses of Narrow Joints Caused by Construction Process of CRTSIISlab Track

MOE Key Laboratory of High-speed Railway Engineering, Southwest Jiaotong University, Chengdu 610031, China.

^* Corresponding author : a Yongjian Zhu,zyjian1987@163.com

Abstract

A separate finite element model of 1/4 unit track slab of CRTS IIslab track was established for the analysis of the influence of construction process on stresses of narrow joints. When track slabs were connected by tension and when wide joints hardened, the impacts of the longitudinal connection of CRTS IIslab on stresses of narrow joints were analysed. The results show that when track slabs are connected by tension, the bonding states between track slab and mortar layer have little effect on track slab expansion displacement and the re-compression of narrow joints caused by the tensioning force cannot be ensured. If track slabs are connected by tensioning force after the concrete hardening of narrow joints, compressive stresses of narrow joints can be increased by 3.03 MPa. Due to the influence of longitudinal connection of CRTSIIslab, the respective track slab temperature for wide joints hardening Tk and narrow joints hardening T_z are difficult to keep consistent. When wide joints hardened, it potentially makes the compressive stresses of narrow joints zero or very large. In order to keep the narrow joints compressed when wide joints hardened, the measures to control T_z and T_k should be taken to make T_k slightly higher than T_z.