加宽路基沥青路面反射裂缝防治技术研究

发布时间：2019-02-20 07:36

【摘要】：加宽路基沥青路面的反射裂缝不但导致使路面使用性能老化,影响行车舒适性,而且由于路表水下浸,从而影响路基的强度与稳定性。在行车荷载重复作用和周期性变化环境温度的影响下,经常使得裂缝迅速向四周扩展,从而大大缩短了罩面层的使用寿命。对于加宽路基反射裂缝的形成和发展,一般认为由于温度变化引起混凝土收缩和交通荷载驶过接缝,使得缝端附近的沥青混凝土材料内产生应力集中,导致沥青路面反射裂缝的产生和发展。温度变化时路面基层长度发生变化,在接缝／裂缝处诱发拉伸应力。若此接缝处的沥青面层拉伸强度不足则很快出现裂缝。国内外沥青路面的各种防裂效果的防裂效果和机理不相同,而且各类措施防裂效果很有限。所以,如何采取措施以较少或延缓路面的反射裂缝应根据加宽路基结构的实际情况,从加宽路基填土控制以及沥青路面相关辅助材料等多方面的情况入手,综合利用多种措施与方法对路基路面进行处理以达到最佳的裂缝防治效果。本论文针对公路加宽扩建工程中,影响路基变形与稳定的关键技术问题,以拉林至五常至省界扩建工程项目为依托,通过现场勘察与试验研究,对新旧路基下地基性状变化规律进行了对比分析,提出了压实度控制标准,并为数值分析提供可靠的计算参数；对路堤加宽工程路基变形性状及路堤稳定性进行了弹塑性有限元分析,研究了各相关因素对加宽路堤变形与稳定规律的影响,提出了相应的建议,给出了推荐方案；探讨了加宽工程的路基变形规律,制定了相应的施工工艺和方法,提出了路基沉降与变形的控制对策和质量控制标准。对于新旧路基结合部容易产生的两种裂缝形式,以土工格栅防治反射裂缝为主要研究对象,数值模拟路基结合部产生不同裂缝宽度和不同差异沉降的路面结构应力分布状态,得出土工格栅的最佳铺筑位置、格栅防治裂缝的适用条件；对土工格栅及其防治裂缝效果进行相关试验,探讨了格栅强度的变化规律和防止裂缝延缓的效果；对不同温度下的层间抗剪性能进行分析,确定不同品种沥青的最佳沥青用量,并对不同铺筑方式进行试验推荐出最佳施工方案。研究成果对提高公路加宽扩建项目的工程质量和使用寿命具有重要的理论意义与实践意义。
[Abstract]:The reflection crack of widening roadbed asphalt pavement not only leads to the aging of pavement performance and affects driving comfort, but also affects the strength and stability of roadbed because of the underwater immersion of road surface. Under the influence of repeated traffic load and periodic variation of ambient temperature, cracks often expand rapidly, thus greatly shortening the service life of the overlay. For the formation and development of reflection cracks in widening roadbed, it is generally believed that the shrinkage of concrete and the driving of traffic load through the joints due to the temperature change cause the stress concentration in the asphalt concrete material near the joint end. Causes the asphalt pavement reflection crack the generation and the development. When the temperature changes, the length of the base course changes and the tensile stress is induced at the joint / crack. If the asphalt surface at this joint is insufficient in tensile strength, cracks will occur quickly. The anti-cracking effect and mechanism of asphalt pavement are different at home and abroad, and the anti-crack effect of all kinds of measures is very limited. Therefore, how to take measures to reduce or delay the reflective cracks of the pavement should be based on the actual situation of the widening subgrade structure, from the widening subgrade fill control and asphalt pavement related auxiliary materials and so on. Comprehensive use of a variety of measures and methods for subgrade and pavement treatment to achieve the best crack prevention effect. This paper aims at the key technical problems which affect the deformation and stability of roadbed in highway widening and extension project, based on the extension project from Lalin to Wuchang to the province, through field investigation and experimental research. The variation law of foundation behavior under new and old subgrade is compared and analyzed. The compaction control standard is put forward, and the reliable calculation parameters are provided for numerical analysis. The deformation behavior of embankment and embankment stability in embankment widening project are analyzed by elastic-plastic finite element method. The influence of relevant factors on deformation and stability of widening embankment is studied. The corresponding suggestions are put forward and the recommended scheme is given. This paper probes into the law of roadbed deformation of widening engineering, formulates the corresponding construction technology and method, and puts forward the control countermeasures and quality control standards of subgrade settlement and deformation. For the two kinds of cracks which are easy to produce in the joint of new and old subgrade, the stress distribution state of pavement structure with different crack width and different settlement is simulated numerically by taking geogrid to prevent reflection crack as the main research object. The optimum paving position of geogrid and the suitable conditions for preventing and controlling cracks of geogrid are obtained. The related tests on geogrid and its crack prevention effect are carried out, and the variation rule of grid strength and the effect of preventing crack delay are discussed. Based on the analysis of the interlayer shear resistance at different temperatures, the optimum asphalt content of different asphalt varieties is determined, and the best construction scheme is recommended by the test of different paving methods. The research results have important theoretical and practical significance for improving the engineering quality and service life of highway widening and expansion projects.
【学位授予单位】：东北林业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U416.217;U418.6

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