为了探究轮胎条-黄土混合物(scrap tire strip-loess mixture,STR-LM)在直剪过程中的剪切特性,优化轮胎条掺量和形状特征,提高资源的循环利用率,利用Shear Trac-Ⅲ型大型直剪仪进行室内剪切试验,考虑轮胎条掺量(0%,10%,20%,30%,100%)及长宽比(u=1,2,4,8)对黄土抗剪强度的影响。结果表明:除素土及轮胎条掺量为10%之外,所有试样均表现出应变硬化特征;轮胎条掺量、长宽比的增加对提高黏聚力有显著影响,而对内摩擦角的影响较小;在试验范围内得出20%为最优掺量,STR-LM黏聚力相对于素土增加了56.5%;正应力为24 kPa和48 kPa时,长宽比为4时STR-LM取得较大的剪切强度,正应力为96 kPa和144 kPa时,长宽比为2时抗剪强度较大。STR-LM抗剪强度较素土最多提高了22%,从试验上证实了废弃轮胎改良黄土效果显著。研究成果对于将轮胎橡胶应用于湿陷黄土的地基处理及回填领域具有一定的工程指导意义。
Abstract
The purpose of this research is to obtain the shear performance of scrap tire strip-loess mixture, thus improving the recycled utilization through optimizing the dosage and shape parameter of scrap tire strip. Indoor shear tests were conducted on large-scale direct shear apparatus Shear Trac-Ⅲ. The dosage of scrap tire strips were designed at 0%, 10%, 20%, 30%, 100%, and the length-width ratio of scrap tire strip at 1, 2, 4, and 8 to examine the influences of dosage and shape parameter on the shear strength of the mixture. Results revealed that except for plain soil and soil mixture with 10% of scrap tire strip, the mixture specimens all displayed strain hardening behavior. Increments in dosage and length-width ratio of scrap tire strip had evident impact on improving cohesion, but small impact on internal friction angle. Within the test range, the optimal dosage of scrap tire strip is 20%. At this dosage, the cohesion of soil mixture increased by 56.5% compared with that of plain soil. Under normal stress of 24 kPa and 48 kPa, the soil mixture had large shear strength when the optimal length-width ratio was 4, while under normal stress of 96 kPa and 144 kPa,large shear strength can be achieved when the length-width ratio equaled 2. The shear strength of scrap tire strip-loess mixture was up to 22% higher than that of plain soil, indicating a remarkable amelioration of loess by using scrap tire strips.
关键词
大尺寸轮胎条 /
黄土 /
掺量 /
长宽比 /
剪切特性
Key words
large-scale scrap tire strip /
loess /
dosage /
length-width ratio;shear performance
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基金
西北民族大学国家级大学生创新创业训练项目计划资助项目(201810742095)
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