【正文】 he entire assembly is laterally supported at the base on twin steelplate tubes, because the shear stiffness of the outer tube goes to zero at the base of the building. Cellular structures A classic example of a cellular structure is the Sears Tower, Chicago, a bundled tube structure of nine separate tubes. While the Sears Tower contains nine nearly identical tubes, the basic structural system has special application for buildings of irregular shape, as the several tubes need not be similar in plan shape, It is not unmon that some of the individual tubes one of the strengths and one of the weaknesses of the system. This special weakness of this system, particularly in framed tubes, has to do with the concept of differential column shortening. The shortening of a column under load is given by the expression △=∑fL/E For buildings of 12 ft () floortofloor distances and an average pressive stress of 15 ksi (138MPa), the shortening of a column under load is 15 (12)(12)/29,000 or () per story. At 50 stories, the column will have shortened to in. (94mm) less than its unstressed length. Where one cell of a bundled tube system is, say, 50stories high and an adjacent cell is, say, 100stories high, those columns near the boundary between .the two systems need to have this differential deflection reconciled. Major structural work has been found to be needed at such locations. In at least one building, the Rialto Project, Melbourne, the structural engineer found it necessary to vertically prestress the lower height columns so as to reconcile the differential deflections of columns in close proximity with the posttensioning of the shorter column simulating the weight to be added on to adjacent, higher columns. 結(jié)構(gòu)系統(tǒng)抵抗橫向荷載 常用的結(jié)構(gòu)體系 與負(fù)載檢測成千上萬 kips ，很少有房的設(shè)計(jì)，高層建筑的過于復(fù)雜的想法。這并不是說，富有想象力的結(jié)構(gòu)設(shè)計(jì)可以創(chuàng)造偉大的建筑。 由于固有的靈活性柱 /梁相交，并且由于初步設(shè)計(jì)的目標(biāo)應(yīng)該是突出的弱點(diǎn)的系統(tǒng)，這是不尋常使用中心到中心尺 寸為框架的初步分析。該系統(tǒng)的 TEM 的進(jìn)一步利用具有高韌性的功能特別重要的地區(qū)的地震活動(dòng)。 筒中筒結(jié)構(gòu) 管狀框架系統(tǒng)動(dòng)員每欄外墻抵制過度轉(zhuǎn)向和剪切力。在這里，內(nèi)胎是一個(gè)支撐框架，外管 沒有剪切剛度和兩個(gè)系統(tǒng)耦合如果他們被視為系統(tǒng)通過直線的 “ 帽子 ” 的結(jié)構(gòu)?？s短一欄下，給出了負(fù)載的表達(dá) △ = ∑fL / 電子 建筑物的 12英尺（三點(diǎn)六六米）落地式地板的距離，平均壓應(yīng)力 15 ksi （ 138MPa ） ，縮短一欄下的負(fù)荷是 15 （ 12 ）（ 12 ） / 29000 或 （一點(diǎn)九毫米）的故事。 7 .類似的空間桁架位于底部的建設(shè) 8 .整個(gè)大會(huì)是橫向支持的基礎(chǔ)上對雙鋼板管，因?yàn)榧羟袆偠鹊耐夤艿搅愕幕A(chǔ)上建設(shè)。這是最簡單的不足立場在內(nèi)胎設(shè)想作為支撐（即剪切激烈），而管外管被視為一個(gè)框架（即剪切靈活）管。的桁架放在往往機(jī)械樓層，玉米粥的反對設(shè)計(jì)師的機(jī)械系統(tǒng)。張力缺乏系統(tǒng)的基礎(chǔ)，任何結(jié)構(gòu)性因素是有限的能力抵抗傾覆力矩的寬度系統(tǒng)和重力負(fù)載支持因素。這種幀被用作一個(gè)獨(dú)立的系統(tǒng)或與其他系統(tǒng)，以便提供必要的抵抗水平荷載。 特別是最近的趨勢更為復(fù)雜的形式，但在反應(yīng)還需要增加剛度抵制軍隊(duì)從風(fēng)和地震，最高層建筑結(jié)構(gòu)體系已經(jīng)建立起來的組合 框架，支撐 bents ，剪力墻，和相關(guān)系統(tǒng)。 analysis by the socalled portal method of the cantilever method has no place in today?s technology. Because of the intrinsic flexibility of the column/girder intersection, and because preliminary designs should aim to highlight weaknesses of systems, it is not unusual to use centertocenter dimensions for the frame in the preliminary analysis. Of course, in the latter phases of design, a realistic appraisal injoint deformation is essential. Braced Frames The braced frame, intrinsically stiffer than the moment –resisting frame, finds also greater application to higherrise buildings. The system is characterized by linear horizontal, vertical, and diagonal members, connected simply or rigidly at their joints. It is used monly in conjunction with other systems for taller buildings and as a standalone system in lowto mediumrise buildings. While the use of structural steel in braced frames is mon, concrete frames are more likely to be of the largerscale variety. Of special interest in areas of high seismicity is the use of the eccentric braced frame. Again, analysis can be by STRESS, STRUDL, or any one of a series of two –or three dimensional analysis puter programs. And again, centertocenter dimensions are used monly in the preliminary analysis. Shear walls The shear wall is yet an