干湿循环效应对纤维膨胀土抗剪强度室内试验研究  

Influence of Wet-dry Cycles on the Shear Strength of Expansive Soil Modified by Fiber

作　　者：陈翔[1] 张福海[1] 张晓阳[1] 贺祖浩 

机构地区：[1]河海大学岩土工程研究所,南京210098

出　　处：《科学技术与工程》2015年第19期175-179,共5页Science Technology and Engineering

摘　　要：为探究干湿循环效应对纤维膨胀土抗剪强度的影响，进行了大量的干湿循环和直剪试验。纤维含量按0％，0.1％，0．2％．0．3％，0．4％来设计，干湿循环次数为0～6次。试验结果表明：①随着干湿循环次数的逐渐增加，内摩擦角先是小幅度提高，然后逐渐减小并趋于稳定；随着干湿循环次数的逐渐增加，黏聚力则是逐渐减小并趋于稳定，其衰减规律基本符合二次函数；②随着干湿循环次数的增加，抗剪强度逐渐减小，在干湿循环1—3次的时候衰减幅度较大；之后逐渐减小并趋于稳定；③适当的增加上覆荷载，能够有效地抑制纤维膨胀土在干湿循环过程中强度的衰减。综合比较干湿循环效应对纤维膨胀土内摩擦角和黏聚力的影响，当纤维含量在0．3％时，对纤维膨胀土在干湿循环过程中抑制抗剪强度的衰减作用明显。To study the impact that the wet-dry cycles cause on the strength of expansive soil and fiber expansive soil, a large number of wet-dry cycles and direct shear test were carried out. Before the shear tests, fiber content by 0%, 0. 1%, 0. 2%, 0. 3%, 0.4% to design, dry-wet cycles of 0 - 6 times. The experimental results showed that： ①with the gradual increase in the wet-dry cycles, internal friction angle slight increase first, and then gradually decreased and stabilized ; With the gradual increase in the number of cycles of wet-dry, the cohesion is gradually reduced and stabilized, the attenuation of line with a quadratic function ; ②with the increase of the wetdry cycles, shear strength decreased Seriously, and then gradually decreased and stabilized; ③ an appropriate in- crease in the cover load could effectively suppress the attenuation of strength caused by wet-dry cycles in fiber expansive soil. When the fiber content was 0.3% , the attenuation of shear strength induced by wet-dry cycles could be effectively alleviated, comparing the effects of friction angle and cohesion of fiber expansive soil in wet-dry cycles synthetically.

关 键 词：干湿循环 膨胀土 纤维 抗剪强度 

分 类 号：TU443[建筑科学—岩土工程]