主应力

At last, through the analysis of the T-stress, it is concluded that the T-stress plays an important role for the oriented microcrack cases. It is necessary to consider the effect of the T-stress in determining the shielding or amplification effect of the oriented microcracks.

最后，本文采用离散模型研究了各向异性材料主微裂纹干涉问题中T应力对主裂尖应力强度因子的影响：T应力对主裂尖应力强度因子的影响是不能被忽视的，这种影响不但与微裂纹的几何分布有关，而且还与T应力的大小和符号有关。

At the same time,it designed the project of construction supervision and measure aimed at the strengthening bridge by external presttessing,through the contrast between the result in theory and fact,we can see that it is feasible to use predigestion's computing based on elasticity to analyse continuous rigid frame briges reinforced by external presttessing ,and it can ignore the effect of the second stress. So, it can be capable of the analyses in the strengthening bridge by external presttessing using the method of controlling by flexibility and stress to set up the model of scathe,and,the method of external presttessing can ensure stress reserve of the main beam, to reduce effectively PrinciPal tensile stress, to renew line state of bridge structure and gradient. The effect of strengthenment was obvious and the reinforcement scheme was successful.

同时，进行了该桥体外预应力加固监测方案设计，并通过理论计算结果与实际监测成果的比较，验证了在施工阶段及正常使用阶段，大跨连续刚构体系的体外预应力加固计算中忽略二次应力增量的影响，采用弹性分析方法进行简化计算的可行性，进而说明采用双控拟合方法建立的结构损伤模型能够满足体外预应力加固计算的要求，并且体外预应力加固法能够显著增大主梁的应力储备、有效地减少了主拉应力、恢复了桥面线形和坡度，加固效果明显，加固方式成功。

Took Sanchaji suspension bridge in Changsha as a case study, based on different hypothesis, two methods were deduced, the parabola method of cable gravity distributing uniformly along the span, and the catenaries method of gravity distributing equally along the curve.

以长沙市三汊矶湘江大桥为工程背景，对自锚式悬索桥的主缆线形及无应力长度的计算方法进行了研究，推导出两种基于不同假定下的主缆线形及无应力索长的计算方法：假定主缆自重沿跨径均布的抛物线法和假定主缆自重沿弧长均布的分段悬链线法。

The results show that space finite analysis results are close to test ones, bottom chords suffer axial force and large in-plane bending, and the max stress is nearby each middle internode. The max stress of node crossbeams occurs in No.2 bottom flange, and that of internode crossbeams happens in ones lying in the middle of every internode. The concrete slab is in tension at the longitudinal direction, and also suffers bent at vertical loads. The degree of completely-composite model taking part in the combined actions is about 55%, while that of semi-composite model is 42%-43%. The combination of concrete slab and bottom chord increases the degree of floor system taking part in the combined actions, lightens the burden of bottom chord, and reduces out-of-plane bending of node crossbeams especially the ones near bridgehead. Stress and displacement of main truss can be evaluated by a equivalent plane rigid frame in preliminary design, and effective stiffness of bottom chords are composed of original ones and concrete slab, and the concentrated load from deck can be translated into uniform load.

研究结果表明：空间有限元分析结果与试验结果较吻合；下弦杆受到轴向拉力和较大的面内弯矩作用，各节间最大应力出现在节间中点附近；节点横梁最大应力发生在横梁2的下翼缘，节间横梁最大应力发生在位于端节间中部的小横梁上；混凝土板顺桥向整体受拉，并在竖向集中荷载作用下产生弯曲变形；全结合模型大部分节间内的桥面板参与主桁共同作用的程度为55%左右，半结合模型桥面板的参与程度为42%~43%；桥面板与下弦杆结合能够增加桥面板的参与程度，减轻下弦杆荷载，减少节点横梁尤其是靠近桥头横梁的面外弯曲；对桥梁进行初步设计时，主桁杆件的位移与内力可按照1个等效的平面刚架计算，下弦杆的等效刚度由原下弦杆截面和混凝土桥面板截面组合而成，桥面荷载可转化为均布荷载施加。

The directions can be obtained by removing the quarter -wave plate a nd following the precedure for plane polarized light or by interpolation.

可将四分之一波片卸去，并按平面偏振光法或内插法来决定其主应力方向。

The orientation of the principal stresses relative to the directions of the polarizer and first quarter-wave plate is of course immaterial.

主应力相对于起偏镜和第一个四分之波片方向的方位，当然是无关紧要的。

Test results have shown that larger plastic volumetric strain as well as higher growth rate of pore water pressure would be generated in multi-directional shearing than in a single-directional one. Lower resistance of sand to liquefaction was also observed under the rotation of principal stress orientation.

与单向剪切相比，多向剪切会产生额外的塑性体积应变，在不排水条件下孔隙水压力增长的速率较高，特别是在具有主应力轴连续旋转特点的加载条件下，砂土抵抗液化的能力也将更低。

In-situ monitoring gave the following results: 1 a tension stress zone occurred at the bottom of reinforced rock mass which indicated that the role of rock bolting was remarkable; 2 stress concentration at surrounding rock of main shaft was gradually transferred from shaft wall to complete rock mass far from shaft center; 3 vertical displacement was gradually smaller from up to bottom and from center to outside of the reinforced loose rock mass.

首先，建立了主溜井三维有限元计算模型，模拟了主溜井围岩的塌落破坏过程和加固后的加固体的稳定性及变形特性；同时，还采用多点位移计等对加固体的稳定性进行了实地监测。计算结果表明：网棚锚注加固体的纵剖面上的压力和位移规律是①加固体下部局部出现拉应力区，表明锚杆的使用是合理的；②加固体内的应力由塌落中心向周围围岩过渡，应力越来越大，最终将荷载传至围岩中；③从下到上下沉逐渐减小；④从加固体中心到周围下沉位移逐渐减小，且近似一条抛物线。

Changing formula forms of single-shear, twin-shear and three-shear yield strength criteria, show that many of yield strength criteria of rock and soil materials can be expressed by the τ8 = gf function forms unter the ordinary condition, and that the main differ ences of yield strength value will mainly forcus on the different function forms of gθσ among single-shear, twin-shear and three-shear yield strength criteria.

对岩土体常用的单剪屈服强度准则、双剪屈服强度准则和三剪屈服强度准则进行了系统的论述，通过对单剪、双剪和三剪屈服强度准则进行转化，指出岩土的屈服强度准则一般可表达为τ8=gf的函数形式，阐明了单剪、双剪和三剪屈服强度准则的差异主要表现在g函数的不同，并进一步解释了中间主应力σ2对岩土类材料屈服强度的影响。

The tectonic stress field is strike-slip motion, and the direction of maximal stress is controlled by the subduction of the Indian plate, Pacific plate and Philippine Sea plate.

4现代构造应力场以水平向构造应力场作用下的走滑运动为主，最大主应力方向受印度板块和太平洋板块、菲律宾海板块的俯冲挤压方向影响。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。