应变式直剪仪与微型十字板剪切仪测定土壤抗剪强度的对比分析.

[Objective] This study aims to analyze the characteristics of soil shear strength parameters obtained by strain-controlled direct shear apparatus and micro-vane shear apparatus, respectively (soil cohesive forcec, internal friction angle, and soil shear force τ), and then establish the relationship between c, and t. This can deepen the understanding of soil shear strength, and have important significance for improving the efficiency of soil shear strength measurement. [Methods] Three typical texture types of soil (Yangling clayey soil, Ansai loessial soil, Dingbian sandy soil) from the Loess Plateau, and five levels of soil moisture (12%, 16%, 20%, 24% and 28%) were designed to obtained their soil shear strength using the above mentioned apparatuses. The responses of soil shear strength to soil types and soil moisture, as well as relationships between c, and were then analyzed. [Results] (1) Under experiment conditions, the values of c, and range between 16.88~27.12 kPa, 5.03°~21.30°, 1.76~7.72 kPa, respectively. (2) In the three soil types, the cand firstly increase and then decrease with the increase of soil moisture. While, the decreases gradually with the soil moisture increase. (3) The c., and of Ansai loessial soil are similar or slightly higher than those in Dingbian sandy soil, while they are significantly higher than those in Yangling clay soil. (4) In the three types of soil, there is a significant linear correlation between the and c (R²> 0.93), while there is no significant correlation between the and r. Without considering the difference of soil type, there is still a strong linear correlation between and c, and its relation can be described by c=1.59τ+ 14.10 (R=0.51, p<0.01). [Conclusion] The responses of c to soil type and soil moisture were similar to that of r. and a significant relation are found between c and r. It implies that researchers can use r. conveniently obtained by micro-vane shear apparatus, to assess obtained by strain-controlled direct shear apparatus slowly under some conditions. The results can provide reference for improving the measurement efficiency of soil shear strength under extreme field conditions. [ABSTRACT FROM AUTHOR]