【摘要】：加寬路基瀝青路面的反射裂縫不但導致使路面使用性能老化,影響行車舒適性,而且由于路表水下浸,從而影響路基的強度與穩(wěn)定性。在行車荷載重復作用和周期性變化環(huán)境溫度的影響下,經(jīng)常使得裂縫迅速向四周擴展,從而大大縮短了罩面層的使用壽命。 對于加寬路基反射裂縫的形成和發(fā)展,一般認為由于溫度變化引起混凝土收縮和交通荷載駛過接縫,使得縫端附近的瀝青混凝土材料內(nèi)產(chǎn)生應力集中,導致瀝青路面反射裂縫的產(chǎn)生和發(fā)展。溫度變化時路面基層長度發(fā)生變化,在接縫／裂縫處誘發(fā)拉伸應力。若此接縫處的瀝青面層拉伸強度不足則很快出現(xiàn)裂縫。國內(nèi)外瀝青路面的各種防裂效果的防裂效果和機理不相同,而且各類措施防裂效果很有限。所以,如何采取措施以較少或延緩路面的反射裂縫應根據(jù)加寬路基結(jié)構(gòu)的實際情況,從加寬路基填土控制以及瀝青路面相關(guān)輔助材料等多方面的情況入手,綜合利用多種措施與方法對路基路面進行處理以達到最佳的裂縫防治效果。 本論文針對公路加寬擴建工程中,影響路基變形與穩(wěn)定的關(guān)鍵技術(shù)問題,以拉林至五常至省界擴建工程項目為依托,通過現(xiàn)場勘察與試驗研究,對新舊路基下地基性狀變化規(guī)律進行了對比分析,提出了壓實度控制標準,并為數(shù)值分析提供可靠的計算參數(shù)；對路堤加寬工程路基變形性狀及路堤穩(wěn)定性進行了彈塑性有限元分析,研究了各相關(guān)因素對加寬路堤變形與穩(wěn)定規(guī)律的影響,提出了相應的建議,給出了推薦方案；探討了加寬工程的路基變形規(guī)律,制定了相應的施工工藝和方法,提出了路基沉降與變形的控制對策和質(zhì)量控制標準。 對于新舊路基結(jié)合部容易產(chǎn)生的兩種裂縫形式,以土工格柵防治反射裂縫為主要研究對象,數(shù)值模擬路基結(jié)合部產(chǎn)生不同裂縫寬度和不同差異沉降的路面結(jié)構(gòu)應力分布狀態(tài),得出土工格柵的最佳鋪筑位置、格柵防治裂縫的適用條件；對土工格柵及其防治裂縫效果進行相關(guān)試驗,探討了格柵強度的變化規(guī)律和防止裂縫延緩的效果；對不同溫度下的層間抗剪性能進行分析,確定不同品種瀝青的最佳瀝青用量,并對不同鋪筑方式進行試驗推薦出最佳施工方案。研究成果對提高公路加寬擴建項目的工程質(zhì)量和使用壽命具有重要的理論意義與實踐意義。
[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.
【學位授予單位】：東北林業(yè)大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：U416.217;U418.6

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