Research On The Durability Of Foundation Plate In Continuous-Slab-Track On Bridge

Durability is a important factor ensuring the techno-economic rationality ofballastless-track structure. Generally ballastless track design does not include the designand the calculation of durability. It is necessary to research durability of ballastless track,which mainly include crack control and fatigue check.Continuous - Slab - Track on bridge is quite different in its structure and componentsand design theory. The key component is foundation plate. This paper discusses the twomain items of durability—crack and fatigue. This paper analysis the probable reasonsand Influencing factors of cracking, and anti-fatigue problem of foundation plate.This paper researches foundation plate's design method based on the theory of stiffnessreduction by Max Bogl, calculates and checks width of the crack referring calculatingmethod used in China. Study shows that the two methods have some relevance, and canbe used to calculate the maximum crack width in different conditions. Reinforcementratio is the key factor that influences crack width, to meet the requirement of currentcode, a larger reinforcement ratio is needed.This paper establishes a calculation model of fatigue. The model utilize 3D finiteelements to simulate the main components, considering foundation plate's bendingrigidity, can be used to analysis force and displacement and local stress of the structuremore comprehensively. It declares that the fatigue performance of foundation platedepends on stress level and fatigue limit of steel. The fatigue stress amplitude limitrequired in Concrete Structure Design Code is broad comparatively; the limit providedby steel's S-N curve and design use life of ballastless track is less.In their long-term working life, track slabs, mortar and foundation plates will crackinevitably. This paper calculate and analysis with consideration of this item, finds thatthe moment of foundation plate and the force of steel changes.