剪切应变

The main factors affecting the soil-structure interface behaviors were found experimentally and theoretically, including: 1 the thickness of the interface that is five to six times the average grain size of the soil; 2 the aeolotropy of interface, which is responsible for anisotropic response of the stress-strain response of the interface; 3 two physical states, including crashing and compression of the soil near the structure surface, which govern the stress-strain response of the interface strongly; 4 two shear deformation components due to sliding and constraint of the structure surface relative to the soil respectively, which forms the deformation of the interface; 5 the volumetric strain due to dilatancy, which is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. 4. A unified constitutive model of the interface, based on new elasto-plasticity damage theory, was developed. It was confirmed to be effective for the conditions considering monotonic and cyclic shearing, coupling effect of shear and volumetric strains, evolution of physical state, micro-structure aeolotropy of the soil and the resulting aeolotropy of the interface as well as the three normal boundary conditions stated above. 5. 2D and 3D finite element formulations of the present model were derived and incorporated into the FEM codes. They were applied to the evaluation of practical engineering problems with different typical interfaces between soil and structure. The new model was shown to be reasonable and effective.

确定了粗粒土与结构接触面厚度约为5～6倍的平均粒径，首次揭示了接触面的细观结构异向性以及由此所引起的宏观剪切异向性，发现了在单调和往返剪切荷载作用下土颗粒破碎和剪切压密两种物态变化机制共同支配着接触面力学性质的变化，通过细观分析证实了接触面的变形可分解为一般同时发生的土与结构交界面上的滑移变形以及结构面位移约束范围之内土体本身的剪切变形两部分，观测到接触面受剪时表现出明显的相对法向位移，并可分解为可逆性和不可逆性两个分量；(4)建立了第一个能够统一地描述单调与往返剪切特性、剪应变与体应变耦合特性、细观结构和宏观剪切异向性以及土颗粒破碎等物态变化特性的土与结构接触面弹塑性损伤本构数学模型，并采用多种法向边界条件复杂加载路径的试验成果验证了新模型的合理性和有效性；(5)提出了新模型的二、三维有限元格式并结合实际边值问题进行了应用计算分析，比较了不同接触面本构模型对计算结果的影响，证实了新模型及其有限元格式不仅能够合理地描述土与结构接触面的主要力学特性，还能够较好地反映土体与结构物在接触面处的滑移、脱开等不连续现象。

Five main phenomena were found, firstly, the high plasticity clay could well suitable to large deformation, and had strain-hardening behavior obviously, as well as, the little dilatancy; secondly, there was no correlation between stress paths and shear strength but the stress-strain relations were influenced by stress paths; thirdly, the little stress increment ratio, the higher increase speeding of shear stress and breaking strength under the condition of same initial normal stress; the fourth, the relations between normal strain and normal stress in simple shear test was consistent with which in the single-direction compression test, if there was no dilatancy; the last, the curve of relation between stress ratio and shear strain could be well simulated by hyperbola.

试验结果表明，高塑性粘土能够较好地适应大变形，接触面剪应力与切向应变关系呈剪切硬化型曲线，法向剪胀不明显；接触面剪切强度与应力路径无关，应力应变关系与应力路径密切相关；初始法向应力一定，应力增量比越小，剪应力增长越快，对应的破坏剪应力也越高；无剪胀发生情况下，法向应变与法向应力关系曲线与单向压缩试验具有一致性；应力比与切向应变呈良好的双曲线关系。

The plastic deformation induced due to cyclic rotation of principal stress axes alone can be in the same magnitude as that due to shear with fixed principal stress axes. 2 The volumetric strain due to shearing of cyclic rotation of principal stress axes is found to be composed of a reversible dilatancy component and an irreversible dilatancy component. The former is characterized by its reversibility and is independent of past shear history, the latter by its irreversibility increases with the increase of cycle number yet its increase rate decreases with its accumulation. 3 The obvious non-coaxiality between directions of the principal stresses and principal strain increments is found and its degree depends largely on the change of shear stress component. 4 The intermediate principal stress has considerable effects on the deformation behavior of sands in the condition of cyclic rotation of principal stress axes. The accumulation rate of the irreversible dilatancy component increases with the increase of the intermediate principal stress parameter.

具有初始各向异性的砂土在纯应力主轴循环旋转排水条件下的主要变形规律为：①纯应力主轴循环旋转可产生与应力主轴固定单调剪切处于同一数量级的塑性变形；②纯应力主轴循环旋转引起的剪切体变包含可逆性剪切体变分量和不可逆性剪切体变分量两部分，其中可逆性剪切体变分量在一周内可完全恢复，基本与应力历史无关；不可逆性剪切体变分量随循环周数的增加呈单调增加，且增加速率随其自身累积值的增大呈减小趋势；③应变增量主轴与应力主轴之间的非共轴现象显著，且在一周内具有分段性；④中主应力对应力主轴循环旋转条件下砂土的变形特性有重要影响，不可逆性剪切体变分量的累积速率随中主应力系数的增加而增加。

In this paper, based on the triaxial test, it is discovered that the structured loess has special mechanical effect of shearing strain rate, and it is proved that the structured loess also has the phenomena of strain rate softening. The CU shear strength and cohesion c increase at first, then decrease with the increase of strain rate, and a critical rate exists; the angel of internal friction doesn't change visibly with the strain rate.

通过结构性黄土三轴试验研究，发现结构性黄土具有独特的剪应变速率力学效应，"应变速率软化"现象同样存在于结构性黄土中；其CU剪切强度和凝聚力c随剪应变率的增大而呈现先增大后减小的特征，存在临界速率现象，而内摩擦角随剪切速率的增大基本上呈线性减小的趋势。

Taking the remolded soil after K 0consolidation and the samples under special stress state by special stress path as the objects, the effect of stress path circumgyration on shear modulus and the trend of shear modulus along with strain under condition of small strain are studied.

以重塑土经K0固结形成的试样以及经K0固结后通过特殊应力路径达到特定应力状态的试样为对象，研究了在小应变范围内应力路径旋转对土体剪切模量的影响以及剪切模量随应变变化的趋势。

Under the condition of small strain, the initial value of shear modulus increased along with the increment of angle θ between trail stress paths and recent stress history. If the two directions were entirely reverse, the effect of stress path circumgyration on shear modulus was the largest; if they coincided completely, the effect was very feeble.

研究表明，在小应变范围内，剪切模量的初始值随试验应力路径与近期应力历史间的夹角θ的增大而增大，当两者完全相反时，应力路径旋转对土体在小应变条件下的剪切模量影响最大；完全一致时，其影响最弱。

The test object was remolded soil after K0 consolidation. Using advanced stress path triaxial system, STDTTS+UNSAT (7kN/1700 kPa) produced by GDS of UK, the effect of stress path circumgyration on shear modulus and the trend of shear modulus along with variation of shear strain under small strain were studied. Some conclusions were drawn.

以重塑土经K0固结形成的试样为试验对象，采用英国GDS公司生产的STDTTS+UNSAT (7kN/1700 kPa)型号高级应力路径三轴测试系统，研究了在小应变范围内应力路径旋转对土体剪切模量的影响以及剪切模量随应变变化的趋势。

Finite strain measures and kinematic vorticity analysis of deformed granite in mylonitic zone show that ductile shear zone is between plane strain and constraint strain and belongs to lengthening-thinning shear zone. Sub-striking stretch lineation in ductile shear zone and dip strea on brittle fault surface are not result of transferring of lineation but production of different deformations.

糜棱岩带变形花岗岩的有限应变测量和运动学涡度分析显示剪切带总体应变为介于平面应变与拉长应变之间的类型，属一般加长-减薄剪切带；断层系中近走向线理和倾向擦痕不是线理转化的结果，而是不同阶段变形的产物。

The detachment fault zone is a low temperature shear zone with top to the E to SE extensional shearing and has typical S-L mylonites with both shearing and flattening strains.

拆离断层带是一个上盘向E到SE伸展剪切的低温剪切带，由具有剪应变和压应变的典型SL糜棱岩构成。

The results show that the formation of the shear band is characterized with both strain localization and the localization of the averaged pure rotation ratio. The shear band starts right at the point where the volume strain changes from shrinkage to expansion. The development of these variables are significantly different within or outside of the shear band. Particularly, the stress-strain softening relationship was observed near or within the shear band, while the hysteretic phenomenon takes place outside the shear band. In addition, both the volumetric and deviatoric strains are larger inside than outside the shear band, with the soil being looser in the shear band.

研究表明：砂土剪切带的形成过程即为试样内部应变局部化过程，也为试样内部平均转动率(averaged pure rotation rate， APR)的局部化；剪切带开始形成点也为试样剪缩、剪胀分界点；剪切带内外各宏微观参数变化规律上存在明显的差异，主要表现为近剪切带位置土体及带内土表现为应变软化现象，而距带中心较远土体应力应变关系曲线出现'回滞圈'现象；带内变形量明显大于带外，且带内较带外松散。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。