不同瓣型荞麦壳加筋黄土的强度特性  

Experimental study on the strength characteristics of reinforced loess with different petal-shaped buckwheat husks

作　　者：雷胜友[1] 文晓灿 LEI Shengyou;WEN Xiaocan(Highway School, Chang'an University, Xi'an 710064, P.R. China)

机构地区：[1]长安大学公路学院,西安710064

出　　处：《土木与环境工程学报（中英文）》2022年第5期118-127,共10页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(59479017);铁道部科技研究开发项目(2010G003-F);地质灾害防治与地质环境保护国家重点实验室开放基金(GZ2005-03);国家级大学生创新创业训练计划(S202010710008)。

摘　　要：为了探索植物壳生态加筋土的强度特性,进行了荞麦壳加筋黄土的剪切试验研究。首先,进行了荞麦壳和黄土的基本性质试验,然后,将荞麦壳分瓣,按一定的干土质量比将分瓣好的荞麦壳添加到配好的湿土中,击实成样,进行直剪试验。试验结果表明:荞麦壳加筋黄土的剪应力剪切位移曲线的变化规律与素土相似;荞麦壳加筋后土的强度有明显提高,最大提高23%;加筋后土的内摩擦角有很大提高,最大提高了6.13°,而黏聚力则有不同程度降低,其降低值不超过8 kPa;只有当荞麦壳的加筋率大于某百分比时,荞麦壳加筋土的强度才大于素土,该百分比与荞麦壳的分瓣情况有关。对于荞麦壳加筋材料,存在一个界限加筋率,当加筋率小于界限加筋率时,荞麦壳起作用所需的剪切位移基本上随垂直压力而增大,当加筋率大于界限加筋率时,荞麦壳起作用所需的剪切位移随垂直压力的增大而减小,该界限值也与荞麦壳的分瓣情况有关。比较而言,天然荞麦壳和两瓣型荞麦壳作为加筋材料更合适。In order to explore the strength characteristics of ecologically reinforced soil with plant shells,the authors conducted a series shear test study on the loess reinforced with different petal-shaped buckwheat husks.First,we carried out the tests on the basic properties of buckwheat husks and loess,and then divided the buckwheat husks,added the divided the buckwheat husks to the soil according to a certain mass ratio of buckwheat husks to dry soil,compacted them into specimens,and carried out direct shear tests.The research results showed that the change law of shear stress-shear displacement curve of buckwheat husk reinforced loess is basically the similar to that of plain soil.The strength of the soil reinforced with buckwheat husks has been significantly improved,with a maximum increase of 23%.In terms of strength indicators,the main manifestation is that after reinforcement,the angle of internal friction of the soil has been greatly improved,with the maximum increase of 6.13°,while the cohesion has decreased to varying degrees,but the decrease is not much,within 8 kPa.It was also found that when the addition rate of buckwheat husk is greater than a certain percentage,the strength of buckwheat husk reinforced soil is greater than that of plain soil,and the percentage was related to the splitting of buckwheat husk.When the buckwheat husk is used as a reinforced material,there is a limit reinforcement rate.When the reinforcement rate is less than the limit reinforcement rate,the shear displacement required for the buckwheat husk to function generally increases with the increase of the vertical pressure.When the reinforcement ratio is greater than the limit reinforcement ratio,the shear displacement required for the buckwheat husk to function roughly decreases with the increase of the vertical pressure,the limit value is also related to the splitting of the buckwheat husk.In comparison,natural buckwheat husks and two-petal buckwheat husks are more suitable as reinforcing materials.

关 键 词：生态加筋土 荞麦壳 瓣型 包裹作用 分隔作用 内摩擦角 

分 类 号：TU444[建筑科学—岩土工程]