地震工程学报Issue(2)：233-238,248,7.DOI:10.3969/j.issn.1000-0844.2014.02.0233
重塑黄土抗拉强度试验研究
Study on the Test of Tensile Strength of Remolded Loess
摘要
Abstract
The mechanical characteristic of loess is the most important factor that influences the stability of buildings,slopes,tunnels,underground structures,etc.Research on its tensile strength and related properties is less compared with the research on shear strength,collapsibility,and oth-er loess properties.The tensile strength of soils is seldom considered in engineering exploration, design,and stability analysis,because its tensile capacity is too weak and thus seems meaningless to common engineering.However,increasing infrastructure,such as railways,highways,airports, and high earth-rock dams,are being constructed in loess areas and natural hazards like landslides and slope avalanches keep occurring,so on one hand,the tensile strength and anti-cracking capaci-ty of loess has become much more significant to the stability of earth structures in loess.On the other hand,the very weak tensile ability of loess often has an adverse effect on research into its tensile characteristics.Because the tensile strength of loess is so small,any small change caused by sampling or testing might lead to serious deviation of test results.Therefore,rigorous test param-eters and correct testing procedures are gravely needed.Using the unconfined penetration test, tensile strength characteristics of the remolded loess from the Lanzhou Jiuzhou Development Zone are thoroughly studied.The advantage of the unconfined penetration test is its simplicity and short duration.For testing,a strain-controlled triaxial apparatus is applied with different loading rate,specimen height,specimen preparation method,and penetration loading cylinder diameter, but the moisture content and dry density of the loess samples remains constant.Because the ten-sile strength of loess is very small,test error due to manipulation is inevitable,so variations in ten-sile strength of remolded loess with different factors are investigated with three sets of parallel tests for each factor.The test results indicate that tensile strength is affected mainly by the load-ing rate,specimen height,specimen preparation method,and diameter of loading cylinder.Howev-er,the influencing degree is much different per factor.For instance,the variation of tensile strength from different tests was the smallest if the loading rate was 1.0 mm/min.The tensile strength of a specimen with the ratio of height to diameter of 1∶1 was the middle one in tensile strength from different tests;meanwhile,the relative value of these tensile strengths was the minimum.The tensile strength of specimens measured by the static pressing method is higher than that by the compaction method.The tensile strength of specimens decreases linearly with the increasing of the different diameter of loading cylinders.For other loess samples with different moisture content and density,more research is needed into other factors that might affect the ten-sile strength of the remolded loess and related soils.The test method and study results can be used for valuable reference for the testing of tensile strength of loess and similar soils and also for providing fundamental data and theoretical evidence.关键词
重塑黄土/抗拉强度/加载速率/制样方法/高径比Key words
remolded loess/tensile strength/loading rate/sample preparation method/ratio of height to diameter分类
建筑与水利引用本文复制引用
李春清,梁庆国,吴旭阳,王丽丽,徐善常..重塑黄土抗拉强度试验研究[J].地震工程学报,2014,(2):233-238,248,7.基金项目
国家自然科学基金（41262010）；长江学者和创新团队发展计划（IRT1139）；兰州交通大学青蓝人才工程项目 （）
