隧道内CRTS Ⅲ型板式无砟轨道自密实混凝土纵向连续方案研究

Study on Longitudinal-continuous Scheme of Self-compacting Concrete Layer for CRTS Ⅲ Slab Ballastless Track in Tunnel

隧道内CRTS Ⅲ型板式无砟轨道服役环境较好,既有的单元分段式轨道结构具有一定优化空间。通过ABAQUS有限元软件建立不同长度自密实混凝土纵向连续的轨道结构空间模型,计算考虑轨道结构的横向稳定性及整体温度荷载作用时轨道板和自密实混凝土的受力和变形,研究自密实混凝土的合理纵向连续长度。结果表明:为满足轨道结构横向稳定性和较小的内部应力,推荐3块轨道板长度的自密实混凝土纵向连续;为实现较小的轨道结构变形,推荐自密实混凝土全部纵向连续,且为防止板端横向裂纹出现后自密实混凝土内钢筋屈服,建议自密实混凝土内纵向钢筋在板端位置设置1.5 m的伸缩套管。

The service environment of CRTS slab ballastless track in tunnel is better, and the existing unitsectional track structure has certain optimization space. The spatial models of track structure with differentlongitudinal- continuous lengths of self- compacting concrete layer were established based on ABAQUS finite elementsoftw are. Considering the lateral stability of track structure and the overall temperature load,the stresses anddeformation of slab and self- compacting concrete layer were computed. The reasonable longitudinal- continuouslength of self- compacting concrete layer was analyzed. The results show that three track slabs connected length ofself- compacting concrete layer is recommended to satisfy the lateral stability and smaller internal stress of trackstructure. To reduce the deformation of track structure, all longitudinal connected self- compacting concrete layer isrecommended, and in order to prevent the steel bar in self- compacting concrete layer yield when the transversethrough cracks appear, 1. 5 m telescopic pipe should be set up on the longitudinal steel bar of the self- compactingconcrete layer at the end of slab.