CAJ | 학술논문

在大量冻融试验和动三轴试验的基础上，深入研究和分析了经历多次冻融循环后粉砂土动模量和阻尼比的变化规律。研究结果表明：同一动应变水平下，动应力大小与冻融次数、含水率呈负相关性，而与围压、加载频率、压实度呈正相关性；粉砂土的动应力-动应变关系存在明显的非线性，且随动应变水平的提高，动模量成倍减小，而阻尼比则成倍增大；随冻融次数的增加，动模量降低而阻尼比则增大，且经历6次冻融后均趋于稳定，建议将6次冻融后的力学特性作为设计与计算指标；围压和压实度的提高有效增强了土颗粒之间的骨架作用，动模量随围压和压实度的增减而增减，阻尼比则随围压和压实度的增加而降低；含水率的变化对阻尼比的影响不大，而当土样达到饱和状态时，动模量成倍降低；加载频率对阻尼比的影响较大，并随频率的提高而迅速降低。
재대량동융시험화동삼축시험적기출상，심입연구화분석료경력다차동융순배후분사토동모량화조니비적변화규률。연구결과표명：동일동응변수평하，동응력대소여동융차수、함수솔정부상관성，이여위압、가재빈솔、압실도정정상관성；분사토적동응력-동응변관계존재명현적비선성，차수동응변수평적제고，동모량성배감소，이조니비칙성배증대；수동융차수적증가，동모량강저이조니비칙증대，차경력6차동융후균추우은정，건의장6차동융후적역학특성작위설계여계산지표；위압화압실도적제고유효증강료토과립지간적골가작용，동모량수위압화압실도적증감이증감，조니비칙수위압화압실도적증가이강저；함수솔적변화대조니비적영향불대，이당토양체도포화상태시，동모량성배강저；가재빈솔대조니비적영향교대，병수빈솔적제고이신속강저。
Based on amount of freeze-thaw tests and dynamic triaxial tests, the dynamic modulus and damping ratio properties of silty soil subjected to repeated freeze-thaw cycles were deeply researched and analyzed. The tests results are drawn as follows:At the same dynamic strain level, the relationships of dynamic stress and freeze-thaw cycles, water content present negative correlation, and the relationships of dynamic stress and confining pressure, frequency, compactness present positive correlation. The curves of dynamic stress vs. dynamic strain obviously present nonlinear relationship; and the dynamic modulus double decreases while the damping ratio double increases with the increasing of dynamic strain. The dynamic modulus sharply decreases while the damping ratio increases with the increasing of freeze-thaw cycles; and then the changes level off after 6 freeze-thaw cycles; while the mechanical properties after 6 freeze-thaw cycles are suggested for designing and calculating indexes. The soil particles contact area is improved by the increasing of confining pressure and compactness; and the dynamic modulus increases while the damping ratio decreases with the increasing of confining pressure and compactness. It is found that water content less affects damping ratio, but the dynamic modulus double decreases when the silty soil reaches saturation condition. The frequency is an important factor affecting on damping ratio, and damping ratio sharply decreases as the frequency increases.