Study on shear strength of water repellent red clay under optimal water content

doi:10.14088/j.cnki.issn0439-8114.2022.24.032

Abstract

Abstract: Under the same humidity environment, the moisture content of water repellent soil was obviously less than that of natural soil at the same time. Therefore, after measurement, the sample selects the optimal moisture content as the initial moisture content for the shear strength test of water repellent red clay. Octadecyl primary amine [CH₃（CH₂）₁₆CH₂NH₂, referred to as Octadecyl Amine] was used as water repellent, and different vertical pressure and water content were used as variables to carry out the direct shear test. Three kinds of soil, repellent, natural, repellent and 30% repellent sand, were compared. The results showed that the water repellency of water repellent soil was closely related to the soil moisture content, and the water repellent intensity was significantly higher than that of under the optimal moisture content, but the water repellent intensity of natural soil was higher than that of water repellent soil under the same moisture content. At this time, the ductility of water repellent soil was reduced, and the ductility was improved by adding water repellent sand to water repellent soil. The strength and water repellency of soil were related to water content. It was difficult for water to enter the water repellent soil, and the decrease of matrix suction was not obvious, so the cohesion c of water repellent soil was large under the optimal water content.

Key words: shear strength, octadecyl amine, vertical pressure, moisture content, direct shear test, repellent soil

CLC Number:

TU43

WANG Chun-hua, FU Shu-yan, HU Meng-fan, ZHANG Cai-yi, OU Bin. Study on shear strength of water repellent red clay under optimal water content[J]. HUBEI AGRICULTURAL SCIENCES, 2022, 61(24): 149-152.

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