单向预应力宽枕板结构设计及力学特性研究

摘要

A unidirectional prestressed broad sleeper slab is proposed to solve the problem in quick and easy repair of the damaged existing prefabricated track slab and the cast-in-place slab bed.In order to validate the design of broad sleeper slab to meet the demands of its construction,transport and normal service,the bending,fatigue and crack resistance characteristics of the unidirectional prestressed broad sleeper slab are calculated based on numerical analysis method.The mechanical characteristics of the broad sleeper slab under lifting condition as well as the reasonable width of the polyethylene foam board under the broad sleeper slab are simulated based on finite element analysis method.The results show that the mechanical properties of the broad sleeper slab can meet the design requirements with sufficient safety margin and the design of the reinforcement of the broad sleeper slab can ensure its safe service.The design of broad sleeper slab can ensure the safety of the broad sleeper slab during lifting or supporting operations in construction and transportation.Taking into consideration of the bending moment and the stress level of the broad sleeper slab surface and the construction technology,the paper suggests 500mm as the reasonable width of the polyethylene foam board under the broad sleeper slab.%为解决不良地质区域既有预制轨道板和现浇道床板破坏后难以快速、便捷修复的问题,提出一种单向预应力宽枕板的设计方案.为验证宽枕板的设计能够满足其施工、运输及安全服役需求,基于数值分析方法对单向预应力宽枕板的抗弯特性、疲劳特性及抗裂特性进行结构检算,基于有限元分析方法对宽枕板在起吊状态下的受力特性进行模拟,并对宽枕板板下聚乙烯泡沫板的合理设置宽度进行研究.结果表明:宽枕板的各项力学特性均能满足设计要求,且具有较大的安全余量,宽枕板的配筋设计可以确保其安全服役需求;宽枕板的设计可以确保其在施工或运输等过程中起吊或支承的安全性;宽枕板下泡沫板宽度取500 mm时,可使宽枕板的弯矩水平和道床表面应力水平均处于较低的水平,且满足现场施工工艺要求.