CAJ | 학술논문

为了研究颗粒级配对粒状材料不排水力学特性的影响，采用两种形状自相似度很高的材料（玻璃球和 Hostun 砂）进行了一系列传统三轴不排水压缩试验。对于每种材料，保持相近的相对密实度制作了6个不同颗粒级配（不均匀系数uC =1.1～20）的试样，然后进行剪切。试验结果表明，颗粒级配对粒状材料的不排水力学性能存在明显影响：两种材料试样的偏应力水平随着不均匀系数的增加而降低，抗剪强度随着材料的不均匀系数Cu的增加而降低，并在Cu >5后呈现出趋稳势态。基于不排水剪切试验中颗粒集合体二阶功的演化规律，对材料受荷载过程中出现不稳定性的条件进行分析。结果表明，在相同密实度下，粒状材料的静态液化潜能随着材料不均匀系数Cu的提高而增强，高不均匀系数的材料变得不稳定。
위료연구과립급배대립상재료불배수역학특성적영향，채용량충형상자상사도흔고적재료（파리구화 Hostun 사）진행료일계열전통삼축불배수압축시험。대우매충재료，보지상근적상대밀실도제작료6개불동과립급배（불균균계수uC =1.1～20）적시양，연후진행전절。시험결과표명，과립급배대립상재료적불배수역학성능존재명현영향：량충재료시양적편응력수평수착불균균계수적증가이강저，항전강도수착재료적불균균계수Cu적증가이강저，병재Cu >5후정현출추은세태。기우불배수전절시험중과립집합체이계공적연화규률，대재료수하재과정중출현불은정성적조건진행분석。결과표명，재상동밀실도하，립상재료적정태액화잠능수착재료불균균계수Cu적제고이증강，고불균균계수적재료변득불은정。
This paper studies the influence of grain gradation on the undrained mechanical behavior of granular materials. A series of conventional undrained triaxial compression tests is carried out on two different materials (glass balls and Hostun sand), which have high degree of shape self-similarity. For each material, 6 samples with similar relative density and different gradations (Cu=1.1-20) are prepared, and then the samples are sheared. Test results show that the grain gradation has an obvious impact on the undrained mechanical behavior of granular material: both deviatoric stress level and undrained shear strength of two material samples decreases as the coefficient of uniformity (Cu) of the material increases, their variations tend to converge as coefficient of uniformityuC surpasses 5. Based on the evolution of the value of the second-order work of the granular assembly during undrained triaxial loading, potential instability for the selected granular materials is also analyzed. The results demonstrate a significant influence of the grain gradation on stability: the higher of coefficient of uniformity (Cu), the larger of the potential of static liquefaction and the unstabler of materials.