滇中红层软岩微观结构及水理特性试验研究

发布时间：2018-05-27 00:21

本文选题：公路工程 + 红层软岩　；参考：《地质与勘探》2016年06期

【摘要】：滇中红层软岩具有成岩作用差、易产生较大变形、遇水易软化、易崩解等特征,本文采用环境扫描电镜试验和水理特性试验,对红层软岩的微观结构特征,崩解、膨胀、软化等水理特性进行了研究。试验结果表明,红层软岩矿物粒间空隙大多被粘土矿物填充,粘土矿物以伊利石和蒙脱石为主,为混层结构,结晶程度相对较差,多数有蚀变的痕迹。具有微小裂隙的红层软岩在1~2次充分饱水烘干后,崩解性开始显现;随着干湿循环次数增加,岩样的质量变化呈减小趋势;干湿循环次数继续增加,崩解性指数趋于平缓。红层软岩由于风化作用影响程度和自然含水率的差异,岩体内部崩解张力具有明显不均匀性。经过自由浸水48h后,红层软岩的单轴抗压强度降低29.83%~58.47%,各地层软化系数在0.4~0.7之间,遇水后呈现显著软化效应。这些结果为红层软岩地区公路工程建设的工程地质研究提供了一定参考。
[Abstract]:The red bed soft rocks in central Yunnan have the characteristics of poor diagenesis, easy to produce large deformation, easy to soften and disintegrate when encountered with water, and so on. In this paper, the microstructural characteristics, disintegration and expansion of red bed soft rocks are studied by using environmental scanning electron microscope test and hydrological characteristic test. The properties of softening isohydration were studied. The results show that the intergranular voids of soft rock in red beds are mostly filled with clay minerals. The clay minerals are mainly Illite and montmorillonite with mixed structure and relatively poor degree of crystallization. Most of them have traces of alteration. The disintegration of red bed soft rock with tiny fissure began to appear after 1 ~ 2 times of fully saturated drying; with the increase of dry and wet cycles, the quality of rock samples decreased; the number of dry and wet cycles continued to increase, and the disintegration index tended to be flat. Due to the influence of weathering and the difference of natural moisture content, the internal disintegration tension of red bed soft rock is obviously uneven. After free immersion for 48 h, the uniaxial compressive strength of red bed soft rock decreases by 29.83% and 58.47, and the softening coefficient of each layer is between 0.4 and 0.7, which shows a significant softening effect after water treatment. These results provide a certain reference for the engineering geology research of highway engineering construction in the soft rock area of red bed.
【作者单位】：陕西铁路工程职业技术学院;张家口职业技术学院;中国矿业大学(北京)地球科学与测绘工程学院;
【基金】：国家自然科学基金项目(编号:10872207)资助
【分类号】：U412

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