摘要
复合轨道板为高速铁路CRTSⅢ型板式无砟轨道的核心部件。基于现场试验开展了复合轨道板自密实混凝土收缩应力、温度翘曲应力及复合轨道板动应力3方面的试验研究,以进一步了解复杂因素作用下复合轨道板的受力特性。研究表明:板下自密实混凝土龄期达到100 d时,其收缩变形趋势逐渐平缓,由约束引起的板下自密实混凝土收缩拉应力约0.7 MPa;研究提出了正温度梯度作用下复合轨道板温度翘曲应力的实用计算式,以及复合轨道板自密实混凝土纵向动拉应力实用计算式,可推算不同温度梯度及动车组作用下复合轨道板承受温度翘曲应力和动拉应力;综合分析表明,在自密实混凝土收缩、温度梯度、列车荷载等因素作用下,复合轨道板承受的静动态拉应力可达4 MPa,应力幅值较大,受力状态较为复杂。
Composite track slab is the key component of CRTS Ⅲ slab ballastless track of high speed railway.The experimental study for shrinkage stress of self-compacting concrete,temperature warping stress and dynamic stress of composite track slab were carried out based on the field tests,and the mechanical characteristics of composite track slab under the action of complex factors were further discussed.The results show that the trend of shrinkage deformation is gradually gentle when the age of self-compacting concrete under the slab is 100 days,the shrinkage tensile stress of self-compacting concrete under the slab /which is caused by constraints,is about 0.7 MPa.The practical calculation formulas of composite track slab temperature warping stress under the action of positive temperature gradient and the longitudinal dynamic tensile stress of the self-compacting concrete in composite track slab were proposed separately /which could be used to calculate the temperature warping stress and the dynamic tensile stress of the composite track slab under the actions of the different temperature gradients and EMU load.The comprehensive analysis show that the static and dynamic tensile stress of the composite track slab could be 4 MPa,the stress amplitude is large and the stress state is complex.
出处
《铁道建筑》
北大核心
2017年第1期30-33,75,共5页
Railway Engineering
关键词
高速铁路
复合轨道板
现场试验
收缩应力
温度翘曲应力
动应力
High-speed railway
Composite track slab
Field test
Shrinkage stress
Temperature warping stress
Dynamic stress
