基于机场水泥混凝土道面板传荷性能的传力杆设计研究

发布时间：2018-03-19 17:06

本文选题：传荷指标　切入点：板底脱空　出处：《中国民航大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国机场水泥混凝土道面在使用后普遍较早地出现了沉陷、错台等损伤,其中由接缝引起的损害约占70%。传力杆的设置在一定程度上改善了道面结构的整体性、提高了传荷性能,但随着飞机荷载作用次数的增加,传力杆会与混凝土粘结界面产生一定的松动,引起接缝传荷能力的衰减。同时,当板底出现不同程度的脱空时,也会引起接缝传荷能力减少,导致混凝土道面结构性能下降,使用寿命降低。因此,接缝设计是机场水泥混凝土道面工程的关键技术之一。在我国现行规范中,接缝传力杆的设计仅与板厚有关,然而,研究表明板的接缝传荷体系受多种因素影响,如基层与面层的层间黏结性能、土基强度、飞机荷载与结构损伤等。目前,相关方面的文献较少,而且大多仅局限于定性方面的研究,未涉及多因素综合影响下有效提高接缝传荷能力的具体实用的设计方法。为此,本文采用考虑接触的三维有限元模型和室内试验,分析道面结构的受力特点以及接缝传荷性能,最终建立考虑多种因素的接缝传力杆设计方法,具体研究内容如下:首先,采用ABAQUS有限元软件建立考虑道面混凝土与传力杆、混凝土面层与基层等各实体层间粘结性能的机场水泥混凝土道面三维有限元模型,研究不同轴载、起落架构型、土基模量、面层与基层接触属性、道面板参数、传力杆参数等多因素对传荷指标以及杆与混凝土界面应力的影响规律。进一步,分析考虑板底脱空和传力杆松动时,道面力学性能和接缝传荷性能的变化规律,并给出了传力杆直径和间距设计的合理建议范围。然后,基于相似理论和圣维南原理,设计接缝设传力杆的水泥混凝土道面结构模型,研究在正常工况以及存在脱空和松动时的位移传荷效率、传力杆和接缝界面混凝土的力学特性。最后,基于正交试验设计理论对影响各传荷指标的多因素进行敏感性分析,建立主要影响因子与传荷指标的定量关系。进而基于布拉德伯利传力杆验算公式,运用MATLAB编辑程序建立水泥混凝土道面板传力杆设计系统。上述研究有助于系统地了解传力杆的传荷机理、道面接缝的应力特性及分布,可为道面板及传力杆的设计和施工提供一定参考依据。
[Abstract]:The cement concrete pavement of airport in our country generally appeared early subsidence, staggered platform and other damage, in which the damage caused by joints accounted for about 70%. The installation of force transfer rod improved the integrity of the pavement structure and the load transfer performance to some extent. However, with the increase of aircraft load, the bond interface between the load transfer rod and the concrete will be loosened to a certain extent, which will lead to the attenuation of the load transfer capacity of the joint. At the same time, the load transfer capacity of the joint will also be reduced when the slab bottom is emptied to different degrees. Therefore, joint design is one of the key technologies in airport cement concrete pavement engineering. In the current code of our country, the design of joint force transfer rod is only related to the thickness of slab. The research shows that the joint load transfer system of the plate is affected by many factors, such as the interlaminar bonding performance between the base layer and the surface layer, the strength of the soil foundation, the aircraft load and the structural damage, etc. And most of them are limited to qualitative research, and do not involve the practical design method which can effectively improve the capacity of joint load transfer under the influence of multiple factors. Therefore, a three-dimensional finite element model considering contact and laboratory tests are adopted in this paper. The stress characteristics of pavement structure and the load transfer performance of joint are analyzed. Finally, the design method of joint force transfer rod considering many factors is established. The specific research contents are as follows: firstly, the concrete and force transfer rod considering pavement concrete and force transfer rod are established by ABAQUS finite element software. The 3D finite element model of the bond behavior between the concrete surface and the base course is studied, and the different axial loads, landing gear configuration, soil modulus, contact properties between the surface and the base, the parameters of the pavement face, the parameters of the pavement are studied. The influence of load transfer parameters and other factors on the load transfer index and the interface stress between the bar and concrete is analyzed. Further, the variation law of the pavement mechanical properties and the joint load transfer performance is analyzed when the slab bottom is empty and the force transfer rod is loosened. Then, based on the similarity theory and the principle of Saint Venant, the cement concrete pavement structure model of the joint transmission bar is designed, which is based on the theory of similarity and the principle of Saint-Venant, and gives a reasonable range of suggestions for the design of the diameter and spacing of the force transfer rod. The displacement load transfer efficiency and mechanical properties of the force transfer rod and joint interface concrete under normal working conditions and in the presence of void removal and loosening are studied. Finally, based on the orthogonal test design theory, the sensitivity of various factors affecting the load transfer index is analyzed. The quantitative relationship between the main influencing factors and the load transfer index is established, and then based on the Bradbury force bar checking formula, In this paper, the design system of cement concrete track face slab force-transfer rod is established by using MATLAB editing program. The above research is helpful to understand systematically the mechanism of load transfer, stress characteristics and distribution of pavement joints. It can provide a certain reference for the design and construction of road face panel and force transfer bar.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.216;V351.11

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