【作者】 易志华；

【导师】 易伟建；

【作者基本信息】 湖南大学 ， 结构工程， 2002， 硕士

【摘要】 本课题在国家自然科学基金项目“混凝土路面板相似理论与损伤诊断研究”(批准号59978015)资助下，进行了不同厚度、不同几何相似比的9块刚性路面板的试验研究。主要内容包括： 1、根据静力荷载下不同相似比的刚性路面板下的土压力测试结果，结合应用相似理论对弹性地基板所作的分析，指出同一场地土上几何尺寸相似的弹性地基板在静载下的力学性能相似。 2、证明相似定律是依尺寸相似比的乘幂关系的规律。试验结果证实了威斯特卡德公式在计算板中与板边加载时荷载随厚度变化关系的正确性。对于板角加载的情况，不具有威氏公式所描述的特点。 3、在分析土体力学性质的基础上，提出土基放大效应的概念，解决刚性路面板计算理论不统一的问题，并解释一些刚性板的工作情况。编制非线性有限元程序，与实测结果对比，证实了土基放大效应概念的合理性。 4、考虑材料尺寸效应，拟合出几何相似的板对于极限荷载的相似规律。所得的公式与Z.P.Bazant用断裂力学方法推得的相似关系比较接近。在此基础上给出了基于缩尺板试验的确定刚性路面板静载下的极限荷载的半弹性方法。这是相似规律能应用于工程实际的关键一步。 5、通过分析极限荷载随板厚的变化，发现板的极限荷载所对应的荷载位置会随板厚的增大发生变化。这是以往弹性分析所没有揭示的结果。板厚超过43cm时，极限荷载以板中加载控制为主。 6、由相似分析得到了几何相似的弹性地基板的频率相似关系。振动测试结果表明，这个关系是基本正确的。更多还原

【Abstract】 The work presented in this thesis is part of the research project-Similitude Laws and Nondestructive Diagnosis on Concrete Pavements, which is supported by China National Science Foundation. 9 slabs were tested to failure with factors of slab thickness, size ratio of geometrically similar slabs and loading place taken into account. The main contents include:1. The mechanics performances of geometrically similar slabs under static load on the same elastic foundation are similar, according to the analysis of slabs with similitude laws and tests of soil stress under rigid pavements with different size ratios.2. The scaling law is a power law if, and only if, a characteristic dimension is absent. The experiments result proved the correctness of Westergaard equations when the load was applied to the middle or the edge of slabs. The situation, which the load was applied to the corner of slabs, was different from what Westergaard equation described.3. Based on the analysis of the mechanic characteristics of the earth, a concept, the magnifying effect of the subbase, was proposed to eliminate the disunity in calculations. Many facts in concrete pavements can be explained by using this concept. A numeric example using the finite element method was given to show the correctness and effect of the concept.4. A fitted equation was given to ultimate load of geometrically similar slabs with size effects taken into account. The equation approached what deduced by Z. P. Bazant with mechanics of failure. A quasi-elastic method was proposed to decide the maximum load of rigid pavements under static load on the basis of experiments of reduced scale slabs, which was the key point for the similitude law to be used practically.5. It was found that the load location changed with the thickness of slabs increasing through the analysis of the relationship between ultimate load and slab thickness. It was never found by any elastic analysis before. The ultimate load was controlled by the load on the middle of slabs when the slab thickness was more thanapproximately 43 cm.6. The similitude law was deduced by analysis of the differential equation of slabs on elastic foundation. The law was proved by the dynamic tests.更多还原