红砂岩工程特性的试验研究及应用

发布时间：2018-05-02 06:48

本文选题：红砂岩 + 工程特性　；参考：《合肥工业大学》2014年硕士论文

【摘要】：红砂岩作为一种不良的填筑材料，是工程建设中经常遇到的一类特殊岩土体，若能充分有效地应用于工程建设中，将具有重要的经济、环境及社会效益。依托绩黄高速路基01标项目，以皖南山区的红砂岩作为研究对象，从资料调研、分析测试、室内试验和工程应用四个方面对红砂岩的工程特性进行了深入系统的研究。采用岩矿鉴定、X射线衍射和X射线荧光光谱等分析测试方法分析了红砂岩的矿物成分组成及微观结构特征；通过室内膨胀性试验和崩解性试验探讨了红砂岩的膨胀机理及崩解机理；开展一系列室内路用性能的土工试验，初步论证了红砂岩直接作为路基填料的可行性；结合试验结果及工程实际应用效果，提出了针对崩解性红砂岩填料路基的设计方法和施工质量控制措施。结果表明：（1）红砂岩岩性多样，结构复杂，多属于粘土类，主要包含蒙脱石、伊利石、高岭石、绿泥石等粘土矿物和SiO2、A12O3、Fe2O3、CaO、K2O、MgO、TiO2、Na2O等化学成分，总体强度偏低，易崩解，抗风化能力偏弱；（2）红砂岩的膨胀性是颗粒的机械膨胀和颗粒晶体体积吸水增大的综合体现，其崩解过程是一个在水介质参与下，由粘土矿物失水、吸水以及胶结物溶解引起的微观结构变化向宏观整体碎裂破坏变化的发展过程；（3）合理控制含水率、压实度等关键指标，，红砂岩的各项路用性能指标均能满足高等级公路的使用要求，可以直接用作路基填料；（4）水是触发红砂岩路基病害的主要外因，要从疏、堵两方面解决好排水、隔水问题，通过适当的机械配置和工艺组合进行破碎、挤密、振压和冲击补强，形成密实不透水的红砂岩压实体，保证红砂岩填料处于相对封闭状态，抑制残余水活性的发挥，可确保红砂岩路基填料的长期稳定性。相关研究结果可为红砂岩地区工程建设提供参考，为相关设计规范和施工规范的制定、修订和完善提供依据。
[Abstract]:Red sandstone, as a bad filling material, is a kind of special rock and soil, which is often encountered in engineering construction. If it can be fully and effectively applied in engineering construction, it will have important economic, environmental and social benefits. Based on the project No. 01 of Ji-Huang high-speed roadbed and taking the red sandstone in southern Anhui mountainous area as the research object, the engineering characteristics of the red sandstone were studied systematically from four aspects: data investigation, analysis and test, laboratory test and engineering application. The mineral composition and microstructure of red sandstone were analyzed by X-ray diffraction and X-ray fluorescence spectrometry. The expansion mechanism and disintegration mechanism of red sandstone are discussed through indoor expansibility test and disintegration test, and a series of geotechnical tests on indoor road performance are carried out, and the feasibility of using red sandstone as subgrade filler is preliminarily proved. Combined with the test results and the practical application effect, the design method and construction quality control measures of the subgrade with crushed red sandstone fillers are put forward. The results show that: (1) the red sandstone has a variety of lithology and complex structure, most of which belong to clay, mainly including clay minerals such as montmorillonite, Illite, kaolinite, chlorite and so on, and the chemical compositions such as SiO2A12O3Fe2O3Fe2O3CaOK2O-MgOTiO2O2Na2O, etc., the overall strength is on the low side, easy to disintegrate, and the ability to resist weathering is weak; (2) the expansibility of red sandstone is a comprehensive manifestation of the mechanical expansion of particles and the increase of water absorption of grain crystals. The disintegration process is a loss of water from clay minerals with the participation of water medium. The development process of the microstructure change from water absorption and the dissolution of the cement to the macroscopic fragmentation and destruction; 3) the key indexes, such as water content and compaction degree, can be controlled reasonably and each road performance index of red sandstone can meet the requirements of high grade highway, and can be used as subgrade filler directly. Water is the main external cause of the red sandstone roadbed disease. It is necessary to solve the problem of drainage and water insulation from the aspects of drainage and blockage, and to crush, squeeze, vibrate and strengthen the roadbed by proper mechanical configuration and process combination. In order to ensure the long-term stability of the red sandstone subgrade filler, the compaction entity of dense and impermeable red sandstone can be formed to ensure the red sandstone packing is in a relatively closed state, and the activity of residual water is restrained, and the long-term stability of the red sandstone subgrade filler is ensured. The relevant research results can provide reference for engineering construction in red sandstone area, and provide basis for the formulation, revision and improvement of relevant design and construction codes.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1;U414

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