CRTSⅢ型板式无砟轨道底座板上设置限位凹槽与上部白密实混凝土凸台相结合,以实现结构层之间的传力、限位功能。该文利用有限元软件建立了路基上CRTSⅢ型板式无砟轨道空间静力分析模型,并利用自主开发的FOSYS动力分析程序建立了车辆一轨道耦合动力学模型,对两种主要凹槽设置方案的轨道结构静、动力学特性进行了对比研究。结果表明:1)温度、车辆、基础沉降荷载作用下,两种方案的结构受力变形略有差异,但均在合理范围内;2)当白密实混凝土与底座板问土工布层摩擦作用不足时,双槽方案结构横向稳定性明显强于单槽方案;3)动力荷载作用下,两方案的动力学指标均满足高速铁路设计规范要求,凹槽设置方式对于轨道结构动力学特性影响较小。综上,两种凹槽设置方案均具有·定可行性,考虑长期使用条件下双槽方案横向稳定性更佳,推荐使用双槽方案。
Recesses are set in the bottom slab of CRTSIII slab track to couple with the bulgy blocks on self-compacting concrete layer so as to transfer forces and restrict displacements. A spatial model for static analysis of CRTSIII slab track on subgrade is established by finite element software, and a vehicle-track coupling dynamic model is established by FOSYS, a dynamic analysis procedure developed by the authors. The statics and dynamics characteristics of a track structure are compared in the cases of two main setting schemes of the recesses. The results show that: 1) the forces and deformations of a track structure in the two cases differ slightly under temperature loads, vehicle loads and foundation settlement, but both are in reasonable range; 2) the lateral stability of a track structure of the double-recess scheme is much better than the single-recess scheme when the friction of the geotextile between self-compacting concrete layer and bottom slab is not great enough; 3) the dynamics indexes of the two schemes all meet the requirements of code for design of high speed railway under dynamic loads. The setting method of position-limitation recesses has little influence on the dynamics characteristics of a track structure. Overall, both of the two schemes are feasible. In the consideration of long term performance, thedouble-recess scheme is better than the other in lateral stability, thusly the double-recess scheme is recommended to apply.