Mechanical Characteristics Research On Welded Turnout Layed On Ballastless Slab On Pile-Plate Structure

ABSTRACT:Pile-plate structure is a new substructure type for ballastless slab used in high-speed railway, composed with reinforced concrete piles, plate, and subgrade soil. Pile-plate structure takes full advantages of the interaction between piles and soil and the interaction plate and soil to meet the strength and settlement requirements of ballastless track. Currently, high-speed railway in a large proportion is bridge, on which lay the welded turnout has a lot of examples and theoretical research. However, there are also many questions about welded turnout layed on bridge due to the complex interaction of turnout and bridge. The pile-plate structure has both advantages of foundation and bridge and there has been no theoretical research about welded turnout layed on it, based on which, the paper carried out research on the mechanical characteristics of welded turnout layed on pile-plate structure to provide theoretical direction for engineering practice. This paper carried out research in the following aspects:(1).Studied the basic mechanical properties of welded turnout layed on ballastless slab on pile-plate structureSpace coupled model of pile-plate structure with welded turnout on ballastless slab on it was established. The law of reaction and deformation of welded turnout on pile-plate structure under temperature force and vertical and longitudinal vehicle force was analyzed and was compared with that of welded turnout on subgrade and bridge. The results showed:the mechanical properties of welded turnout layed on pile-plate structure had both the properties of that layed on subgrade and that layed on bridge, but closer to that layed on subgrade.(2).Analyzed the main factors of welded turnout on pile-plate structure under temperature forceThe track factors and pile-plate structure factors on the mechanical properties of welded turnout on pile-plate structure were studied. The result showed:the style structure at switch rail and rail temperature changes had great influence; pile structure factors were less affected.(3).Analyzed the main factors of welded turnout on pile-plate structure under vehicle forcePile-plate structure factors, such as pile spacing, subgrade soil, bearing plate thickness, pile settlement on the mechanical characteristics of welded turnout on pile-plate structure were analyzed. The results showed:the subgrade soil had the minimal affection, the pile settlement affected most and pile spacing and bearing plate thickness were to a certain extent.