A reasonably accurate assessment of a proposed high-rise structure's behavior is necessary to form a properly representative model for analysis. A high-rise structure is essentially a vertical cantilever that is subjected to axial loading by gravity and to transverse loading by wind or earthquake.

為了合理地精確評(píng)價(jià)一個(gè)選定的高層建筑結(jié)構(gòu)，必須建造一個(gè)能夠正確反映其性能的模型。高層建筑結(jié)構(gòu)基本上是一個(gè)豎向懸臂結(jié)構(gòu)，軸向承受重力荷載作用，橫向承受風(fēng)和地震荷載作用。

Gravity live loading acts on the slabs, which transfer it horizontally to the vertical walls and columns through which it passes to the foundation. The magnitude of axial loading in the vertical components is estimated from the slab tributary areas, and its calculation is not usually considered to be a difficult problem.?Horizontal loading exerts at each level of a building a shear, a moment, and some times, a torque, which have maximum values at the base of the structure that increase rapidly with the building's height. The response of a structure to horizontal loading, in having to carry the external shear, moment, and torque, is more complex than its first-order response to gravity loading. The recognition of the structure's behavior under horizontal loading and the formation of the corresponding model are usually the dominant problems of analysis.?The principal criterion of a satisfactory model is that under horizontal loading it should deflect similarly to the prototype structure.

重力活荷載作用于樓板之上，樓板將其沿水平方向傳遞到豎向的墻和柱，最終傳到基礎(chǔ)。在豎向構(gòu)件中，軸向荷載的大小取決于其所分配到的樓板面積大小，這種計(jì)算通常被認(rèn)為是一個(gè)簡(jiǎn)單的問(wèn)題。作用在建筑物每層間的水平荷載產(chǎn)生剪力、彎矩以及有時(shí)產(chǎn)生扭矩，這些值沿建筑高度向下迅速增大，在結(jié)構(gòu)的基礎(chǔ)處達(dá)到最大值。結(jié)構(gòu)對(duì)水平荷載的反應(yīng)表現(xiàn)在同時(shí)承擔(dān)外部剪力、彎矩和扭矩作用，與結(jié)構(gòu)對(duì)重力荷載的一階響應(yīng)相比要復(fù)雜得多。識(shí)別在水平荷載作用下結(jié)構(gòu)的性能并形成相應(yīng)的模型通常是結(jié)構(gòu)分析的主要問(wèn)題。一個(gè)正確模型的主要判斷標(biāo)準(zhǔn)是在水平荷載作用下模型產(chǎn)生的變形應(yīng)與原型結(jié)構(gòu)產(chǎn)生的變形相似。

The resistance of the structure to the external moment is provided by flexure of the vertical components, and by their axial action acting as the chords of a vertical truss. The allocation of the external moment between the flexural and axial actions of the vertical components?depends on the vertical shearing stiffness of the "web" system connecting the vertical components, that is, the girders, slabs, and bracing. The stiffer the shear connection, the larger the proportion of the external moment that is carried by axial forces in the vertical members, and the stiffer and more efficiently the structure behaves.

結(jié)構(gòu)在抵抗外部彎矩時(shí)，其豎向構(gòu)件受彎并且像豎向桁架弦桿那樣受到軸向作用力。外部彎矩對(duì)豎向構(gòu)件產(chǎn)生的彎曲和軸向作用是根據(jù)連接各豎向構(gòu)件的“腹桿”系統(tǒng)豎向剪切剛度，即梁、 樓板和支承條件進(jìn)行分配的?？辜暨B接的剛度越大，豎向構(gòu)件軸向力所承擔(dān)的外部彎矩的比例就越大，因而結(jié)構(gòu)的剛度和效率就越高。

The described flexural and axial actions of the vertical components and the shear action of the connecting members are interrelated, and their relative contributions define the fundamental characteristics of the structure. It is necessary in forming a model to assess the nature and degree of the vertical shear stiffness between the vertical components so that the resulting flexural and axially generated resisting moments will be apportioned properly.

上面所描述的豎向構(gòu)件的彎曲和軸向作用與連接構(gòu)件的剪切作用是相互聯(lián)系的，他們之間的相互作用就確定了結(jié)構(gòu)的基本特征。有必要建造一個(gè)模型來(lái)評(píng)價(jià)豎向構(gòu)件的性質(zhì)和這些豎向構(gòu)件之間豎向剪切剛度的大小，以便將結(jié)構(gòu)在彎曲和軸向受力時(shí)產(chǎn)生的抵抗彎矩進(jìn)行正確的分配。

The horizontal shear at any level in a high-rise structure is resisted by shear in the vertical members and by the horizontal component of the axial force in any diagonal bracing at that level. If the model has been properly formed with respect to its moment resistance, the external shear will automatically be properly apportioned between the components.

作用于高層建筑結(jié)構(gòu)的層間水平剪力是由豎向構(gòu)件的抵抗剪力和各層間斜支撐構(gòu)件軸向抗力的水平分力共同承擔(dān)。如果建造的模型能夠正確地滿足抗彎要求，外部剪力自然會(huì)恰當(dāng)?shù)胤峙溆诟鳂?gòu)件之間。

Torsion on a building is resisted mainly by shear in the vertical components, by the horizontal components of axial force in any diagonal bracing members, and by the shear and warping torque resistance of elevator, stair, and service shafts. If the individual bents, and vertical components with assigned torque constants, are correctly simulated and located in the model, and their horizontal shear connections are correctly modeled, their contribution to the torsional resistance of the structure will be correctly represented also.

作用于建筑上的扭矩主要是由豎向構(gòu)件的抵抗剪力和各斜支撐構(gòu)件軸向抗力的水平分力，電梯、樓梯、設(shè)備的井筒具有的剪切及彎扭抗力共同分擔(dān)。如果在模型中，對(duì)每個(gè)具有抗扭能力的框架結(jié)構(gòu)和豎向構(gòu)件的模擬和所處位置的確定都是正確的，同時(shí)水平抗剪連接的形式也是正確的，則結(jié)構(gòu)所表現(xiàn)出的抗扭能力也應(yīng)該是正確的。

A structure's resistance to bending and torsion can be significantly influenced also by the vertical shearing action between connected orthogonal bents or walls. It is important therefore that this?is properly included in the model by ensuring the vertical connections between orthogonal components.

交叉框架或剪力墻之間的豎向抗剪作用對(duì)一個(gè)結(jié)構(gòu)的抗彎和抗扭能力能夠產(chǎn)生很大的影響。因此，保證交叉構(gòu)件之間的豎向連接并使其能正確地反映在模型中是非常重要的。

The preceding discussion of a high-rise structure's behavior has emphasized the importance of the role of the vertical shear interaction between the main vertical components in developing the structure's lateral load resistance. An additional mode of interaction between the vertical components, a horizontal force interaction, can also play a significant role in stiffening the structure, and this also should be recognized when forming the model. Horizontal force interaction occurs when a horizontally deflected system of vertical components with dissimilar lateral deflection characteristics, for example, a wall and a frame, is connected horizontally. In constraining the different vertical components to deflect similarly,?the connecting links or slabs are subjected to horizontal interactive forces that redistribute the horizontal loading between the vertical components. For this reason, in a tall wall-frame structure the wall tends to restrain the frame near the base while the frame restrains the wall near the top. Similarly, horizontal force interaction occurs when a structure consisting of dissimilar vertical components twists.?In constraining the different?vertical components to displace about a center of rotation and to twist identically at each level, the connecting slabs are subjected to horizontal forces that redistribute the torque between the vertical components and increase the torque resistance of the structure.

在前面對(duì)高層建筑結(jié)構(gòu)性能的討論中，已經(jīng)強(qiáng)調(diào)了在各主要豎向構(gòu)件之同豎向剪切作用對(duì)結(jié)構(gòu)抵抗水平荷載所具有的重要性。在各豎向構(gòu)件之間還有另一種相互作用形式，即水平力相互作用也具有增大結(jié)構(gòu)剛度的重要作用，應(yīng)該在建造模型時(shí)認(rèn)識(shí)到這一點(diǎn)。當(dāng)各豎向構(gòu)件發(fā)生水平位移時(shí)，由于側(cè)向變形特征不同而引起水平力相互作用，例如水平相連接的框架和剪力墻。在強(qiáng)迫不同的豎向構(gòu)件產(chǎn)生相同的水平位移過(guò)程中，連接桿件或樓板受到水平相互作用力，使各豎向構(gòu)件承擔(dān)的水平荷載重新分配。由于這種原因，在高層框架剪力墻結(jié)構(gòu)中，在基礎(chǔ)附近剪力墻約束了框架，而在建筑物頂部附近框架則約束了剪力墻。同樣，由不相同的豎向構(gòu)件組成的結(jié)構(gòu)扭轉(zhuǎn)時(shí)，也會(huì)產(chǎn)生水乎力相互作用。不同的豎向構(gòu)件受到約束，圍繞一個(gè)扭轉(zhuǎn)中心在每層發(fā)生位移，產(chǎn)生相同的扭轉(zhuǎn)，連接樓板受到水平力的作用使各豎向件之間的扭矩重新分配，增加結(jié)構(gòu)的抗扭能力。