CAJ | 학술논문

有关黄土抗强度及相关特性的研究甚少，其主要原因是土抵抗拉伸的能力过于微弱。近年来随着基础设施建设的快速发展，特别是黄土自然灾害的频发，使人们认识到土的抗拉强度是不能忽略的。而黄土微弱的抗拉能力使得在试验过程中任何操作引起的微小变化都可能导致其强度值的严重偏差，所以有一套严格准确的试验参数和正确无误的试验操作步骤势在必行。本文采用兰州市九州开发区的重塑黄土，用轴向压裂法系统研究了黄土在不同的加载速率、试样高度、制样方法、加载圆柱直径时的抗拉强度。结果表明轴向压裂法测试土体的抗拉强度时上述因素都有不同程度的影响。其中：加载速率在1．0 mm/min 下测定的不同试样强度值间的变化幅度为最小；高径比为1∶1的试样的抗拉强度值既位于不同试样强度值变化过程的中间位置又处于强度相对差值的最小处；静压制样优于击实制样且其抗拉强度较大；抗拉强度测试值随加载圆柱体直径呈线性增大。研究结果可供土体抗拉强度试验参考，也可为土体抗拉强度试验方法的规范化和标准化提供基础数据和理论依据。
유관황토항강도급상관특성적연구심소，기주요원인시토저항랍신적능력과우미약。근년래수착기출설시건설적쾌속발전，특별시황토자연재해적빈발，사인문인식도토적항랍강도시불능홀략적。이황토미약적항랍능력사득재시험과정중임하조작인기적미소변화도가능도치기강도치적엄중편차，소이유일투엄격준학적시험삼수화정학무오적시험조작보취세재필행。본문채용란주시구주개발구적중소황토，용축향압렬법계통연구료황토재불동적가재속솔、시양고도、제양방법、가재원주직경시적항랍강도。결과표명축향압렬법측시토체적항랍강도시상술인소도유불동정도적영향。기중：가재속솔재1．0 mm/min 하측정적불동시양강도치간적변화폭도위최소；고경비위1∶1적시양적항랍강도치기위우불동시양강도치변화과정적중간위치우처우강도상대차치적최소처；정압제양우우격실제양차기항랍강도교대；항랍강도측시치수가재원주체직경정선성증대。연구결과가공토체항랍강도시험삼고，야가위토체항랍강도시험방법적규범화화표준화제공기출수거화이론의거。
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.