箱形梁

The manufacture process is very; the parts and components, including electric motor, reducer, breaker and cable reels, all adopt the updated products; the whole machine has advanced technologies, reliable performance and novel structure; it has many safety protection facilities, such as: overload equipment, height indication equipment, stroke ultimate position terminal protector, electric rail clamp and anemoscope to ensure the normal operation of the equipment.

跨度大，一机多用，可同时装置主钩、副钩等结构；主梁、横梁、支腿等主要结构为箱形梁，强度与刚度好，制造工艺简单；零部件包括电机、减速器、制动器、电缆卷筒等均选用最新产品，整机技术先进，性能可靠，结构新颖；有超载装置、高度指示装置、行程极限位置终端保护装置、电动夹轨器、风速仪等安全设施，保证设备的正常运行。

With the development of the prestressed concrete construction technology, more and more prestressed concrete box girder bridges have arisen in our nation. However, after construction, the appearance of the cracks on some of these bridges takes some unfavourable influence on the structures. In common sense, we should take some methods to strengthen and repair these bridges as soon as possible, but because of the civil pecuniary condition, we cant repair all the broken bridges in one time. Therefore a scientific estimation must be made about the load-carrying capacity of these prestressed concrete box girder bridges with cracks, so that we can decide which bridge should be repaired firstly.

随着预应力施工技术的不断进步，我国已拥有越来越多预应力混凝土箱形梁桥，这些桥在使用一段时间后，有很大一部分箱梁出现了大量的裂缝，这些裂缝的出现对桥梁结构将产生不利的影响，所以应尽可能的对其进行加固修补，但限于国内实际经济状况，我们不可能一次性全部进行加固改造，需要对在役的这些开裂后的预应力梁桥的工作状态特别是承载力做出科学的评判，以便区分轻重缓急，优先实施。

With the development of the prestressed concrete construction technology, more and more prestressed concrete box girder bridges have arisen in our nation. However, after construction, the appearance of the cracks on some of these bridges takes some unfavourable influence on the structures. In common sense, we should take some methods to strengthen and repair these bridges as soon as possible, but because of the civil pecuniary condition, we can't repair all the broken bridges in one time. Therefore a scientific estimation must be made about the load-carrying capacity of these prestressed concrete box girder bridges with cracks, so that we can decide which bridge should be repaired firstly.

随着预应力施工技术的不断进步，我国已拥有越来越多预应力混凝土箱形梁桥，这些桥在使用一段时间后，有很大一部分箱梁出现了大量的裂缝，这些裂缝的出现对桥梁结构将产生不利的影响，所以应尽可能的对其进行加固修补，但限于国内实际经济状况，我们不可能一次性全部进行加固改造，需要对在役的这些开裂后的预应力梁桥的工作状态特别是承载力做出科学的评判，以便区分轻重缓急，优先实施。

Also, the conversion between counteracting force and deflection of the bridge is achieved. The study analyzes on the characteristics of the beams" stress and deformation and gets the beams" vertical fiexture stress and deflection, their rigidity rotation stress and lateral inner force caused by the beams distribution of load.

通过实测结果，得到了桥梁的支反力与挠度，箱梁桥的受力特点：包括纵向弯曲产生的竖向变位，畸变角及由畸变产生的隔板横向弯曲应力，纵向弯曲应力及箱形梁的剪力滞现象及影响因素，箱梁桥刚性转动效应和截面的歪扭情况，箱形梁在局部荷载作用的横向内力，桥面板的有效工作宽度，荷载的横向分配分析。

All nutrition bee feed use: You can open the collection, feeding fermented box beam, box beam fed after soaking.

所有蜜蜂饲料的营养：您可以打开的收集，喂养发酵箱形梁，箱形梁浸泡后喂。

Presenting the calculating method of the space displacement model of skewed box girder, whit main ideas of: dispersing the skewed box girder into some skewed beam segments and further dividing those segments into some plate pieces according to their forms; describing the displacement functions in the plane of plate piece by assuming that the space displacements of any point in the joint line between the plate pieces are described by using Hermite interpolation functions and that two displacements in the plane of plate piece are linear in the cross direction; Using Hermite interpolation functions to describe the bending the displacement of the unit length transverse frame cutting longitudinal from the skew box girder segment; Finally, describing the space displacements of a point in the plate pieces by two displacements in the plane of the plate and one bending displacement of plate.

提出了斜交箱形梁空间位移场的计算方法：将斜交箱形梁沿纵向离散为若干斜梁段单元，依据箱梁的构成进一步将斜梁段划分为若干板段子单元；各板段联结线上任意点的位移按Hermite函数插值，假定各板段的面内位移沿其宽度方向线性变化，以描述各板段面内位移；沿斜交箱梁段的纵向截取单位长度横截面框架，框架各杆件空间位移按Hermite函数插值，以描述各板段面外位移；板段内任意点的空间位移最终以2个面内位移和1个面外位移描述。

The entire Superstructure cross-section, except for traffic barrier, shall be considered to be placed at one time for purposes of determining support requirements and designing falsework girders for their stresses and deflections, except as follows: For concrete box girder bridges, the girder stems, diaphrams, crossbeams, and connected bottom slabs, if the stem wall is placed more than 5 days prior to the top slab, may be considered to be self supporting between falsework bents at the time the top slab is placed, provided that the distance between falsework bents does not exceed 4 times the depth of the portion of the girder placed in the preceding concrete placements.

整个上部结构截面除交通障碍，应被视为在一个确定的要求和支持他们的设计应力和挠度除，脚手架时间放在梁的目的如下：对于混凝土箱形梁桥，主梁茎，diaphrams，横梁，和连接底板，如果干墙放置超过5天前向顶板，可能被认为是自我支持之间的脚手架本茨当时顶端板放置，只要脚手架茨之间的距离不超过4倍，在前面的混凝土主梁部分存款放在深度。

The paper describes how the local force of the main web is considered as the force caused by the Contact pressure among the trolley wheel, rail and top flange, and how the contact analysis model for the local force is built by means of both Hertz theory and finite element software ANSYS combined. Also, it analyzes the variation of the local stress under the different conditions and comes to a conclusion, and compares the results derived from the experimental formula with the result from ANSYS.

本论文的主要内容：将Hertz接触理论和有限元软件ANSYS结合起来，把主腹板的局部受力问题视为小车轮与轨道及轨道与上翼缘板之间发生接触行为作用下的受力问题，建立了小车轮压作用处偏轨箱形梁主腹板局部受力的接触分析模型，研究不同情况（小车轮压、箱形梁几何参数和轨道截面惯性矩）下局部应力的变化规律，得出相关结论；最后将经验公式解与ANSYS数值解进行对比分析论证。

But quite amount of cracks are found during the construction and operation in the PC box girder bridges, especially cracks in the anchorage zone and the inclined cracks in the box girder webs of the bridges, and some longitudinal cracks appear indeed in the deadweight phases,Moreover the variant Pre-stressed strand arrangements produce great influence for the inner inforce of the b

但目前在用预应力混凝土箱形梁的施工和运营过程中出现相当数量裂缝病害，尤其是箱梁锚固区裂缝、腹板斜裂缝，顶板纵向裂缝，有的甚至在未承受活载的自重阶段就出现裂缝，而不同的预应力布束方式对箱梁内力有很大的影响。

In this paper, the through truss composite beam is first equalized to a box beam and the progression solutions to the temperature effect of the composite beam are then obtained with the variation method.

首先将下承式桁梁结合梁等效为箱形梁，再用变分法求出了下承式桁梁结合梁温度效应的级数解，并对京沪高速铁路上的一座简支下承式钢桁结合梁桥进行了计算，其结果可供下承式桁梁结合梁设计参考。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。