张应力

Because the height of box girder is limited, vertical prestressed bar is short, so when control stress of prestressing is attained, elongation of thick high strength thread reinforcing bar is limited.

这是由于箱梁的高度有限，竖向预应力筋的长度都比较短，因而在达到张拉控制应力时高强精轧螺纹粗钢筋的伸长量有限。

Through the numerical simulation analysis, the stress concentrationstatus before the crack splits has been researched, and the have been found. Therelationships between fracture splitting force 、 factor and opening angle,curvature radius、the depth of crackle groove have been carried out.

通过数值模拟，分析了应力集中程度，得出了预制裂解槽张角、曲率半径、槽深对裂解力及几何形状因子的影响曲线。

In studies of interaction among pile, platform that above it and surrounding soil, this paper employ the concept of plate element to simulate the loading character of platform, and employ the concept of solid element to simulate the character of pile and soil, using the finite element method after understanding the geometry properties of pile, soil and the platform. Analyzing the loading properties of the three entities above and their deformation, this paper also employ a special element, Penalty Element. The introduction of penalty element of this kind has served to guarantee the join harmony of displacement between solid element and plate element, thereby effectively resolving the join problem between platforms, pile that support it and surrounding soil.Considering significant property difference between pile material and its surrounding soil, there may be much shear stress on their contact interface produced under vertical load, thus causing displacement or fission. Therefore it is necessary to adopt one special constitutive law of this kind of contact interface, which can reflect its feature of loading and deformation thoroughly. On the basis of the deformation feature and constitutive laws of some contact interface obtained by Zhang Dongji and people concerned through some single-shear experiments on contact interface between structure and soil, this paper employ one pile-soil three-dimensional constant thickness contact interface model to simulate the " slide" taken place on the interface between pile and its surrounding soil. With this kind model, this paper has also created one finite element model, which can be applied to perform finite element calculation and analyze the pile-loading feature, and deduced its element stiffness matrix.

在承台-桩-土共同作用中，考虑桩与承台的几何特性，采用有限元方法，用实体单元模拟桩土，用板单元模拟承台，更具体地分析桩和承台的受力特性和变形，而且还采用罚单元—既实体单元与板单元之间连接必须满足变形协调条件，来有效地解决了承台与桩土的连接问题，且在桩土共同作用中，由于桩体结构的材料性能与周围土层性质相差较大，在竖向荷载下有可能在其接触面上产生较大的剪应力从而导致错动或开裂，因此，为了充分反映桩土接触面上的受力及变形特征，应采用一种桩土接触面特有的本构关系，即利用张冬霁等人关于结构与土体接触面单剪试验所得到的接触面变形特征及其本构关系，引入桩-土三维等厚度接触单元来模拟桩与桩侧土之间的&滑移&，在此基础上建立可用于桩基承载性状分析的有限元计算单元模型，并推导出了各单元的刚度矩阵。

First, based on the relations of stress and strain between the whole medium and its macroscopically isotropic constituents, an explicit relation between elastic matrices of the whole medium and its constituents was derived. Combining the explicit relation of elastic matrices with the strain's relation, two coefficient tensors were defined and analyzed to get a general relation between the hulk and shear modulus of the whole medium under the assumption that all the field variables are in a unified coordinate system. Secondly, combining these relations with the classical Hashin-Shtrikman elastic modulus bounds, four new expressions of elastic medium of the whole medium were obtained and compared with the original hounds. Last, these formulae were applied in the computation of effective elastic moduli of clean sandstone saturated with pore water.

首先基于整体介质与宏观各向同性组分满足的应力和应变组分关系，推导出整体介质弹性矩阵与组分弹性矩阵之间的显式关系，联合其应变关系，定义和分析了对应的两个系数张童，并据此导出了相关场变量位于统一坐标系时整体介质体积模量与剪切模量的关系；然后将经典的Hashin-Shtrikman弹性模量边界模型与上述关系式结合，得到4个新的整体介质弹性模量的估算公式，再与原始的Hashin-Shtrikman弹性模量边界进行了比较，最后针对饱和水纯净砂岩介质进行了试算。

Considered the crustal structure crossing the South Shetland Islands、Bransfield Strait and Antarctic Peninsula,we proposal a two phase rifting tectonical evolution model and layered shear model for the lithospheric deformation under extensional stress field.

通过横穿南设得兰群岛、布兰斯菲尔德海峡和南极半岛的地壳剖面，我们用分层剪切模式解释了在张性应力作用下的岩石圈变形特征。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。