岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2009年
7期
1927-1932
,共6页
栾茂田%聂影%杨庆%齐剑峰%邵琪
欒茂田%聶影%楊慶%齊劍峰%邵琪
란무전%섭영%양경%제검봉%소기
饱和黏土%循环应力路径%耦合循环试验%动强度%应力-应变关系
飽和黏土%循環應力路徑%耦閤循環試驗%動彊度%應力-應變關繫
포화점토%순배응력로경%우합순배시험%동강도%응력-응변관계
saturated clay%cyclic stress path%coupling test of vertical and torsional dynamic test%dynamic strength%stress-strain relation
地基土单元体在波浪荷载的作用下将发生主应力轴连续旋转,这对土的强度和变形特性会产生显著的影响.针对饱和黏土,利用土工静力-动力液压三轴-扭转多功能扭剪仪进行了均等固结下的耦合循环剪切试验,着重研究了不同循环应力路径对应力-应变关系和强度特性的影响.试验结果表明,耦合循环荷载下黏土扭转剪切分量和正向偏差分量的应力-应变关系曲线与应力路径有关,且随着振动次数的增加逐渐疏松,割线模量和不断衰减,这与不固结不排水条件下的应力-应变关系曲线的变化规律明显不同;扭转剪切分量大的椭圆应力路径的动强度略小于正向偏差分量大的动强度.饱和黏土在不同应力路径下的力学特性的试验研究可以为建立复杂应力路径下的本构模型提供试验依据.
地基土單元體在波浪荷載的作用下將髮生主應力軸連續鏇轉,這對土的彊度和變形特性會產生顯著的影響.針對飽和黏土,利用土工靜力-動力液壓三軸-扭轉多功能扭剪儀進行瞭均等固結下的耦閤循環剪切試驗,著重研究瞭不同循環應力路徑對應力-應變關繫和彊度特性的影響.試驗結果錶明,耦閤循環荷載下黏土扭轉剪切分量和正嚮偏差分量的應力-應變關繫麯線與應力路徑有關,且隨著振動次數的增加逐漸疏鬆,割線模量和不斷衰減,這與不固結不排水條件下的應力-應變關繫麯線的變化規律明顯不同;扭轉剪切分量大的橢圓應力路徑的動彊度略小于正嚮偏差分量大的動彊度.飽和黏土在不同應力路徑下的力學特性的試驗研究可以為建立複雜應力路徑下的本構模型提供試驗依據.
지기토단원체재파랑하재적작용하장발생주응력축련속선전,저대토적강도화변형특성회산생현저적영향.침대포화점토,이용토공정력-동력액압삼축-뉴전다공능뉴전의진행료균등고결하적우합순배전절시험,착중연구료불동순배응력로경대응력-응변관계화강도특성적영향.시험결과표명,우합순배하재하점토뉴전전절분량화정향편차분량적응력-응변관계곡선여응력로경유관,차수착진동차수적증가축점소송,할선모량화불단쇠감,저여불고결불배수조건하적응력-응변관계곡선적변화규률명현불동;뉴전전절분량대적타원응력로경적동강도략소우정향편차분량대적동강도.포화점토재불동응력로경하적역학특성적시험연구가이위건립복잡응력로경하적본구모형제공시험의거.
The cell of foundation soil is taken notable impact on dynamic deformation and dynamic strength behavior under rotation of principal stress axes by cyclic wave load. The apparatus for static and dynamic universal triaxial and torsional shear soil testing is employed to perform stress-controlled cyclic coupled vertical and torsional shear test by different cyclic stress paths. Through a series of tests on saturated clay, the dynamic deformation, stress-strain relationship and dynamic strength are systematically investigated under rotation of principal stress axes. It is found that stress-strain relation of shear stress and normal stress has obvious distinguishing between consolidated-undrained and unconsolidated-undrained coupling test by comparing the experiment data. Meanwhile, it is observed that stress-strain relationship curve gradually loosen and the secant modulus decayed as the cyclic number increased. Moreover, it is shown that the dynamic strength under major dynamic shear stress is less than the one under major normal stress by different elliptical stress paths. By conducting experiments on clay with changes in stress paths, the mechanical behavior can be investigated on which the establishment of proper constitutive model for soil is based.