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桩板结构无砟轨道无缝道岔力学特性研究
Mechanical Characteristics Research on Welded Turnout Layed on Ballastless Slab on Pile-Plate Structure
【作者】 郭丽娜;
【导师】 肖宏;
【作者基本信息】 北京交通大学 , 道路与铁道工程, 2010, 硕士
【摘要】 摘要:桩板结构是高速铁路无砟轨道一种新的下部基础结构型式,由钢筋混凝土桩、路基土体和钢筋混凝土承载板组成。桩板结构充分利用桩-土、板-土之间的共同作用来满足无砟轨道的强度和沉降变形要求。目前,高速铁路建设中桥梁的比重大,其上铺设无缝道岔的工程实例和理论研究也有很多。但是由于道岔与桥梁相互作用问题复杂,无缝道岔铺设于桥梁上还存在很多问题。而桩板结构兼具路基与桥梁的优点,在其上铺设无缝道岔还没有相关方面的理论研究,基于此,本文对桩板结构上铺设无缝道岔问题进行理论研究,分析桩板结构上无缝道岔力学特性,为工程实践提供理论指导。本文主要开展了如下几方面的研究工作:(1)研究了桩板结构上无砟轨道无缝道岔基本力学特性建立桩板结构无砟轨道无缝道岔空间耦合模型,分析和得到了其在温度和垂向和纵向车辆荷载作用下的受力和变形规律,并与路基、桥梁无砟轨道无缝道岔做了对比。结果表明:桩板结构无砟轨道无缝道岔受力与变形兼具路基无砟轨道无缝道岔与桥梁无砟轨道无缝道岔的特点,但更接近路基。(2)分析了温度力作用下桩板结构无砟轨道无缝道岔主要影响因素分别讨论了轨道结构因素和桩板结构因素对无缝道岔力学特性的影响。结果表明:轨道结构因素中尖轨跟端结构型式、轨温变化幅度对无缝道岔力学特性有较大影响;桩板结构因素对无缝道岔力学特性影响较小(3)分析了车辆荷载作用下桩板结构无砟轨道无缝道岔主要影响因素分析讨论了桩板结构因素,如桩间距、路基土体、承载板厚度、桩沉降等对无缝道岔在车辆荷载作用下的力学特性影响。结果表明:桩间土体影响最小,桩沉降影响最大,桩间距和承载板厚度变化均有一定程度的影响。
【Abstract】 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.
【Key words】 pile-plate structure; welded turnout; mechanical characteristics; finite element;