【作者】 王海波；

【导师】 赵明华；

【作者基本信息】 湖南大学 ， 岩土工程， 2014， 硕士

【摘要】 随着能源消耗量的急剧增大，火电厂每年排放的粉煤灰量及累积堆存量日益增大，由此带来的一系列环境问题也日益受到全社会的重视，粉煤灰的综合利用变得刻不容缓。近年来，大量的粉煤灰在我国高速发展的高速公路建设中得到利用，粉煤灰堆积场地的处治利用也越来越多。粉煤灰路基以及建筑地基的承载力受到其抗剪强度的影响，而粉煤灰的抗剪强度与含水量和压实度等因素密切相关。同时，国内外对于粉煤灰承载机理的研究，远落后于工程实践。因此，为了更合理有效地对工程实践进行指导，很有必要对粉煤灰的路用性能及其承载机理进行研究。本文通过室内试验，结合相关理论计算和分析，对粉煤灰的路用性能及其承载机理进行了系统研究。首先，综合论述了粉煤灰的化学组成成分和微观组成结构，对其物理性质以及力学特性等基本路用性能进行了试验研究。在此基础上，介绍了粉煤灰土体强度理论，包括摩尔-库仑破坏准则、强度形成机理以及影响因素。然后，通过三轴压缩试验，研究了含水量和压实度对粉煤灰强度的影响，分析了粉煤灰的应力-应变特性。试验结果表明，在试验含水量范围内，随着含水量的增大，粉煤灰的粘聚力先增大后减小，而内摩擦角一直减小。基于试验结果，通过线性回归得到了以含水量为变量的粉煤灰抗剪强度计算公式，该公式误差控制在工程允许范围内，计算参数容易获得。通过构建相关模型，分别利用极限分析上限法和瑞典条分法，对粉煤灰地基承载力计算及边坡稳定性分析进行了研究，探讨了含水量对粉煤灰地基承载力和边坡稳定性的影响。更多还原

【Abstract】 The emission amount of fly ash caused by thermal power plant annually and theaccumulated stockpiles ascended, with the sharp increase of energy consumption. As aresult of the fact, a series of environmental problems have attracted the attention ofthe whole society, the comprehensive utilization of fly ash becomes a matter of greaturgency. For the past few years, a good deal of fly ash were utilized in the rapiddevelopment of China’s highway construction, the available of fly ash accumulationsite treatment soared either. The bearing capacity of Fly ash sub-grade and buildingfoundations are affected by their shear strength. Moreover, water content and thedegree of compaction have a close relationship with the shear strength of fly ash.Meanwhile, the research of bearing capacity mechanism of fly ash around the worldlags far behind their engineering practice. Therefore, it is necessary to carry researchon the road performance and bearing capacity mechanism of fly ash, in order to bemore rational and effective in guiding the engineering practice.The road performance and bearing capacity mechanism of fly ash has beenstudied systematically in the thesis, by taking laboratory tests combined with relevanttheoretical calculations and analysis. A comprehensive review of the chemicalcomposition and microstructure of fly ash is proposed in the dissertation, at the sametime, a wide range of tests is conducted in explaining their basic physical propertiesand mechanical properties. The strength theory of fly ash soil is presented based onthis, which including Mohr-Coulomb failure criterion, the strength formationmechanism and their influencing factors. By performing triaxial compression tests,the influence of water content and degree of compaction on the strength of fly ash isdiscussed, and stress-strain characteristic of fly ash is analyzed. The results of testsindicate that along with the increase of water content under the test range, thecohesion of fly ash increase first and then decrease, however, angle of internal frictionreduced all the time.The shear strength formula of fly ash based on the water content is proposed inthe research by linear regression of the test results. The deviation of the formula iscontrolled under the allowable range of real project, and the calculation parametersare easily available. By conducting related models, the upper limit analysis methodand the Swedish slice method are adopted respectively in terms of calculating the bearing capacity of the fly ash foundation and analyzing the slope stability. What’smore, the compaction of water content on the bearing capacity of fly ash foundationand slope stability is investigated in the dissertation.更多还原