作　　者： ; ;

机构地区： 中山大学

出　　处： 《岩土工程学报》 2005年第10期1136-1141,共6页

摘　　要： 在土体工程性质评价以及土坡稳定性分析中,土体强度研究具有重要意义。本文从土体剪切破裂面的微观结构研究入手,寻求土体达到峰值强度破坏时,剪切破裂面上的微观结构参数与土体强度参数之间的关系。取珠江三角洲中部地区海相沉积的、具有代表性的原状软土样,开展室内实验,获取土的物理力学性质参数;其中在强度实验(直剪实验、三轴固结快剪实验)中,当土体达到剪切破坏时,取破裂面上的土样,进行电镜扫描,得到微结构图像;采用MATLAB6.0软件进行图像处理,并提取微观结构特征参数,建立这些特征参数与强度参数(c,?)之间的关系;并从宏观角度探讨了间接反映土体微观结构特征的宏观土性参数(塑性指数IP和粘粒含量PC)与强度参数c和?之间的关系。说明了软土的抗剪强度与微观结构参数变化之间有着良好的一致性。本研究对于高填方路堤稳定性等问题的分析具有重要价值。 Researches on strength of soft clay have an important significance on the evaluation of engineering property and stability analysis of soil slopes. The relationship between micro-structural parameters of fracture surface and strength of soil, including cohesion and internal friction angles, was discussed when the the peak strength was reached and the soil was faced with failure. Choosing the representative marine soft clay samples in their natural states in the middle area of Pearl River Delta conducting the physical and mechanical tests, a series of data were obtained. Scanning the micro-structure of soils taken from the failure surface when the soil samples reach failure state in the shear test （including direct shear test and quick tri-axial shear test）, the micro-structural images were gained. Then, the relationship between micro-structural parameters and strength coefficients （c and φ） was established by image-processing technique. The relationship between macro-parameters including plastic index（Ip） and clay grain content （Pc） which could well reflect the micro-structural features was discussed. The results showed that the shear strengths of soft soils were coincident very well with the variation of micro-structural parameters. These results could be used in the stability control of high fill engineering etc.

关 键 词： 软土 破裂面 微观结构 强度

领　　域： [建筑科学] [建筑科学]