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由于目前对草甸土的工程性质了解甚少,一方面引起了草甸土与草炭土、泥炭等的混淆,另一方面导致了在设计过程中不知如何选择相应的处治措施。鉴于此,以新疆伊犁昭苏县草甸土层为研究对象,参照一般土体的室内土工试验方法,测试了草甸土的比重、重度、烧失量、渗透系数、抗剪强度、无侧限抗压强度等物理力学指标,并将试验结果与国内外草炭土、泥炭、泥炭质土的工程特性进行了对比分析。结果表明:按照有机质含量分类,新疆昭苏县草甸土属于泥炭质土;其含水率处于泥炭质土的低限附近,而重度则高于一般泥炭和泥炭质土的重度,具有较好的渗透性、很高的压缩性;草甸土中的草根可以显著提高土体的黏聚力,但对内摩擦角的影响不明显;无侧限抗压强度试验过程中草甸土未发生类似于一般黏土的剪切破坏,而是产生了很大的压缩变形和鼓胀变形;草甸土在受荷载后主固结沉降完成很快,其主固结系数随着固结压力的增大线性减小;当固结压力超过100 k Pa时,草甸土的主固结比较小,说明此时草甸土的次固结变形量不容忽视,地基沉降计算中应予以考虑。
Due to the lack of understanding of the engineering properties of meadow soil, the confusion between meadow soil and peat soil and peat is caused on the one hand, and the other is that we do not know how to choose the appropriate treatment measures in the design process. In view of this, taking the meadow soil of Zhaosu County, Yili Prefecture, Xinjiang as the research object, with reference to the indoor soil test method of common soils, the specific gravity, heavyness, loss on ignition, permeability coefficient, shear strength, Compressive strength and other physical and mechanical indicators, and the test results with the peat soil, peat, peat soil engineering properties were contrastively analyzed. The results showed that the meadow soil of Zhaosu County in Xinjiang belonged to peat soil according to the classification of organic matter content; its moisture content was near the lower limit of peat soil, while the severity was higher than that of peat and peat soils Permeability and high compressibility. The grass roots in the meadow soil can significantly improve the cohesion of the soil, but the effect on the internal friction angle is not obvious. The meadow soil does not appear similar in the unconfined compressive strength test However, the shear deformation of the clay is quite large, but the compressive deformation and bulging deformation are very large. The settlement of the main soil after the loading of the meadow soil is completed quickly. The main consolidation coefficient increases with the increase of the consolidation pressure Decrease. When the consolidation pressure exceeds 100 kPa, the main consolidation of meadow soil is relatively small, indicating that the secondary consolidation deformation of meadow soil can not be ignored at this time and should be considered in the calculation of foundation settlement.