川西高原不同纤维含量泥炭质土工程特性研究

Research on engineering properties of peat soils with different fiber contents in the western Sichuan Plateau,China

研究川西高原地区不同纤维含量泥炭土的工程特性。通过一维固结压缩和直剪试验,量化纤维含量对抗剪强度和压缩性的影响,并结合SEM电镜扫描从微观上揭示纤维含量对泥炭土工程特性的影响。试验结果表明:纤维含量与压缩性呈正相关,并影响固结参数;纤维含量对泥炭土抗剪强度有增强作用,随着纤维含量的增高,抗剪强度反而减小;高纤维泥炭土,其抗剪强度主要由摩擦强度所提供,而高分解度泥炭土抗剪强度主要由黏聚强度和摩擦强度共同提供;纤维的存在造成泥炭土组成成分和结构的差异而导致其工程特性有明显差异。研究结果可为进一步完善纤维泥炭土力学机制研究提供参考。

This paper studies the engineering characteristics of peat soil with different fiber content in western Sichuan Plateau.Through one-dimensional consolidation compression and direct shear tests,the effects of fiber content on shear strength and compressibility as well as on engineering properties of peat soil are quantitatively studied and revealed microscopically by SEM analysis.The results show that the fiber content is positively correlated with compressibility and has influence on the consolidation parameters.In fact,fiber content has an enhanced effect on the shear strength of peat soil in such a way that the shear strength decreases with the increase of fiber content.It reveals that the shear strength of high fiber peat is mainly provided by friction strength,while the shear strength of high decomposition peat is mainly provided by cohesiveness and friction strength.The existence of fiber causes the difference of composition and structure of peat soil,which leads to the obvious difference in its engineering characteristics.The research results in this paper can provide reference for further improving the mechanical mechanism of fiber-bearing peat soil.