陡坡急弯路段旧水泥混凝土路面沥青加铺层力学分析

发布时间：2018-01-15 06:00

本文关键词：陡坡急弯路段旧水泥混凝土路面沥青加铺层力学分析　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：目前,国内外很多已修的水泥混凝土路面发生了各种病害,严重影响了路面使用性能,已不再满足交通需求。加铺沥青面层是旧水泥混凝土路面维修改造的主要形式之一,它能够改善路面使用性能、提高路面承载能力和延长服务年限。由于旧水泥混凝土路面存在接缝和裂缝,在交通荷载、温度变化等因素共同作用下扩展并延伸到沥青加铺层中,形成反射裂缝,其结果是破坏了路面结构的整体性,容易形成早期破坏。尤其是在陡坡和急弯路段,路面所受荷载更加复杂、加铺层内力更大,加铺层更容易产生反射裂缝以及车辙、推移等病害。作为防治沥青加铺层反射裂缝的重要措施之一,应力吸收层具有较多的优点,其通常具有较低的弹性模量和较高的韧性,能够通过自身的较强的塑性变形能力来吸收水泥混凝土板接缝处的应力,从而有效减缓反射裂缝的产生和扩展。因此,分析陡坡急弯路段旧水泥混凝土路面接缝处沥青加铺层的受力状态以及研究应力吸收层对加铺层荷载应力的影响具有必要性,本文在前人研究的基础上,继续对这两个问题进行深入地理论分析。本文采用三维有限元方法,利用ANSYS有限元程序,建立了旧水泥混凝土路面沥青加铺层路面结构的三维有限元模型。并运用材料强度理论,分析了在陡坡和急弯路段荷载作用下水泥混凝土板接缝处沥青加铺层的内力响应,以及应力吸收层对加铺层应力的影响。主要研究内容及如下:(1)分析纵坡处不同纵向水平荷载的作用下,沥青加铺层表面和底部的拉应力、剪应力以及接缝处两侧弯沉差的响应规律。(2)探究在纵向水平荷载、横向水平荷载作用下,沥青加铺层内最大主应力、等效应力、最大剪应力、最大拉应变随深度变化的规律。(3)分析在一定的水平力作用下沥青加铺层厚度、模量以及轴载变化对加铺层内力及弯沉的影响。(4)分析应力吸收层厚度和模量变化对沥青加铺层和应力吸收层的荷载应力及弯沉的影响,并探究应力吸收层合理的设置厚度和模量。
[Abstract]:At present, many domestic and foreign cement concrete pavement has been repaired a variety of diseases, seriously affecting the pavement performance. The asphalt pavement is one of the main forms of the old cement concrete pavement maintenance and reconstruction, which can improve the pavement performance. Due to the existence of joints and cracks in the old cement concrete pavement, it is extended to the asphalt overlay under the combined action of traffic load, temperature change and so on. The formation of reflective cracks results in the destruction of the integrity of the pavement structure and easy to form early damage. Especially in steep slopes and sharp bends the load on the pavement is more complex and the internal force of the overlay is greater. As one of the important measures to prevent the reflective cracks of asphalt overlay, the stress absorption layer has many advantages. It usually has lower elastic modulus and higher toughness, and can absorb the stress of cement concrete slab joint through its own strong plastic deformation ability. So as to effectively slow the generation and expansion of reflection cracks. It is necessary to analyze the stress state of asphalt overlay at the joint of old cement concrete pavement on steep slope and to study the influence of stress absorption layer on the load stress of overlay. In this paper, three dimensional finite element method and ANSYS finite element program are used. The three-dimensional finite element model of asphalt overlay pavement structure of old cement concrete pavement is established, and the material strength theory is used. The internal force response of asphalt overlay at the joint of cement concrete slab is analyzed under the load of steep slope and sharp bend section. And the influence of the stress absorption layer on the stress of the overlay. The main contents of this study are as follows: 1) Analysis of the tensile stress on the surface and bottom of the asphalt overlay under different longitudinal horizontal loads on the longitudinal slope. Shear stress and the response law of deflection difference on both sides of joint. 2) under the action of longitudinal horizontal load and transverse horizontal load, the maximum principal stress, equivalent stress and maximum shear stress in asphalt overlay are investigated. The law of maximum tensile strain varying with depth.) the thickness of asphalt overlay under a certain horizontal force is analyzed. The influence of stress absorption layer thickness and modulus on the load stress and deflection of asphalt overlay and stress absorption layer is analyzed. The reasonable thickness and modulus of the stress absorption layer are explored.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.2

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