【作者】 白俊本；

【导师】 席丁民；

【作者基本信息】 西北农林科技大学 ， 岩土工程， 2005， 硕士

【摘要】 粉煤灰是火电厂燃煤锅炉排放出的灰渣废弃物。由于社会经济的大发展,促使了电力工业的发展,从而导致排放的粉煤灰逐年剧增,引起了许多经济和社会问题。如何大量高效的利用粉煤灰已成为现阶段突出的问题。粉煤灰的利用历史悠久,领域广泛,但用灰量不大,为了提高利用率,本文着重研究了它在地基处理中的应用。灰土地基是一种处理湿陷性黄土地基简便、经济、有效的灰土并用的方法,在工程中已经得到了广泛应用。目前应用的灰土地基有一灰土(石灰与黄土)地基和二灰土(石灰、粉煤灰和黄土)地基,但灰土的配比和材料搭配方面的理论研究还远远落后于工程实践,所以本文对灰土的集料搭配和配比选择以及应用数学方法确定灰土成分方面作了进一步的研究探讨。本文首先介绍了提高粉煤灰利用率的紧迫性以及粉煤灰的物理和化学性质,进一步探讨了粉煤灰在灰土地基中的硬化机理。其次通过室内试验,研究了灰土的强度及其影响因素,分析了不同类型搭配材料灰土和不同含灰量黄土灰土的击实性及击实黄土灰土的抗剪性。文中首次提出了在工程中尚未应用的另一类一灰土(粉煤灰和黄土),就其击实性和抗剪性与同种条件下的二灰土进行了对比分析。得出了不同配合比灰土的最优含水量、最大干密度、最大凝聚力和最大内摩擦角,以及灰土的抗剪性随养护龄期的变化规律。与重塑纯黄土直剪试验剪切强度的对比,总结新提出的一灰土的建议性使用配合比为:1:9(粉煤灰:黄土)。这是一个从力学角度和粉煤灰利用率综合考虑的配合比。从二灰土抗剪性的时间效应来确定了其最佳配合比为:1:2:7(石灰:粉煤灰:黄土)。其次应用灰色系统理论中的数学模型进行了二灰土强度因素分析,通过模型的建立与应用,得出影响二灰土强度最主要的因素是石灰与粉煤灰的比率>粉煤灰与石灰和黄土和的比率>粉煤灰率。其中前两项是起正作用,粉煤灰率起负作用。至此为粉煤灰在灰土中的大量应用提供了理论上的依据。更多还原

【Abstract】 The fly ash is the wasted ash that the boiler combusted coal in the fire power station. Because of the development of the Society and economy, urged the development of the power industry, the fly ash of exhaust is increasing year by year, causing many economic and social problems. How in great quantities and efficiently of the exploitation fly ash have become the outstanding problems of present stage. The exploitation history of the fly ash is very long, the realm is extensive, but uses the ash quantity not greatly. For raising the utilization, emphasized to study it on foundation handle of application in the paper. The lime-loess foundation is the method that a kind of processing is the simple, economic and valid collapsible lime-loess foundation to counteract, having already got the extensive application in the engineering. Currently the applied fly ash-loess foundation contain lime (lime and loess) foundation and lime-fly-ash loess (lime, the fly ash and loess) foundation, but the fly ash-loess matching ratio and materials match the aspect of the theories research to still get behind with the engineering fulfillment far and far, so gathers to anticipate to matching ratio with to compare the choice and the applied mathematics method assurance fly ash compositions to make the further study on the fly ash-loess foundation. At first, introduced urgency of the exaltation fly ash utilization and the physics and the chemistry property of the fly ash, further inquiring into fly ash in the fly ash-loess foundation of hardening mechanism in the paper. Through the room experiment, study on the strength of the fly ash-loess and its affects the factor. The suggestion usage was put on one fly ash-loess matching ratio is1:9(fly ash and loess) in the paper. This is a match that synthesizes the consideration from the mechanics and the fly ash of utilization to compare. The next, the time factor from two fly ash-loess make sure its best matching ratio for: 1:2:7(lime, the fly ash and loess) in the sheared experiment. Finally, the mathematics model within applied gray system theories carried on analyses fly ash-loess strength factor.更多还原