【正文】 withstand neither pression nor bending. A calbe carrying a concentrated load at mid span would deform as indicated in Figure 112(a). The whole structure is in tension. If this exact shape were simply inverted and loaded precisely in the same way, it is evident by analogy that the resultant structure would be in a state of39。 畢業(yè)設(shè)計(jì)我們專業(yè)本科培養(yǎng)計(jì)劃的一個(gè)學(xué)習(xí)、實(shí)踐、探索和創(chuàng)新相結(jié)合的實(shí)踐性教學(xué)環(huán)節(jié)，是本專業(yè)人才培養(yǎng)過(guò)程中的重要階段。 對(duì)本設(shè)計(jì)進(jìn)行了混凝土用量的統(tǒng)計(jì)，并與另一位同學(xué)框架結(jié)構(gòu)體系進(jìn)行比較。 4， 強(qiáng)壓弱拉 —— 框架柱的截面尺寸滿足《 抗規(guī) 》第 33 條的要求。多高層建筑的立面內(nèi)收或外挑的尺寸宜符合《高規(guī)》第 條的規(guī)定。基礎(chǔ)設(shè)計(jì)荷載簡(jiǎn)圖如圖十四。樓梯扶手凈高 米，欄桿垂直桿件間的凈空不大于 米。因?yàn)樽≌瑯菢敲婊钶d不大，一般只占全部豎向荷載的 10%15%，其不利分布產(chǎn)生的影響較小，所以一般情況可不考慮豎向活荷載的不利布置。各種荷載性質(zhì)不同，發(fā)生概率也不同，對(duì)結(jié)構(gòu)的作用效果也不同，對(duì)此《建筑結(jié)構(gòu)荷載規(guī)范》 GB5000920xx規(guī)定了必須采用的荷載效應(yīng)組合方法。有關(guān)計(jì)算系數(shù)表詳見(jiàn)《建筑結(jié)構(gòu)靜力計(jì)算手冊(cè)》。對(duì)梁、柱進(jìn)行歸并。其中的剪力墻，如果是單片式的分散布置，則整體布 置剛度較小，建筑高度一般在 1020 層；如果利用一些永久隔墻或固定用途 14 圖四 結(jié)構(gòu)布置簡(jiǎn) 15 圖五 柱布置簡(jiǎn) 16 圖六 梁歸并簡(jiǎn)圖 17 的輔助用房、電梯間、各種管井作為一體的井筒式剪力墻，則整體結(jié)構(gòu)剛度、承載力會(huì)大大提高，也增強(qiáng)了抗扭能力，因此建造高度 一般在 3040 層。 13 3）梁荷計(jì)算 墻體為 240mm 厚粘土空心磚，外墻面帖瓷磚（ kn/m2）內(nèi)墻為 厚抹灰，則外墻單位墻面重力荷載為 +15ⅹ +17ⅹ = kn/m2 梁體的重力荷載標(biāo)準(zhǔn)值取 kn/m2，所以梁荷為 += kn/m2，取 9 kn/m2，對(duì)于頂層及窗洞較大的相應(yīng)梁荷取 6 kn/m2。 柱截面尺寸為： 400mmⅹ 400mm。住宅戶門采用安全防衛(wèi)門。 本工程多層住宅為框架剪力墻結(jié)構(gòu)體系。本設(shè)計(jì)對(duì)七層住宅樓選用框架 剪力墻結(jié)構(gòu)設(shè)計(jì)。運(yùn)用 PKPM 系列軟件進(jìn)行結(jié)構(gòu)和建筑施工圖設(shè)計(jì)，對(duì)基礎(chǔ)進(jìn)行手算設(shè)計(jì)。主體結(jié)構(gòu)共 7 層，層高均為 m。 平面圖設(shè)計(jì)注意門窗的規(guī)范設(shè)計(jì)，窗臺(tái)距樓面、地面的凈高取900mm，底層外窗和陽(yáng)臺(tái)門下沿低于 2m，采取防衛(wèi)措施。 由《建筑抗震設(shè)計(jì)規(guī)范》（以下簡(jiǎn)稱《抗規(guī)》）知該框架結(jié)構(gòu)為二級(jí)，其軸壓比限值 [μ n]=,各層重力荷載代表值近似取 12 kn/m2，梁柱板的混凝土強(qiáng)度等級(jí)為 C30（ fc=,ft=）柱截面尺寸可根據(jù) Ac≥ efN][?計(jì)算。 (II)．荷載標(biāo)準(zhǔn)值計(jì)算 1）屋面及樓面均布永久荷載標(biāo)準(zhǔn)值 屋面（不上人）： 30 厚細(xì)石混凝土保護(hù)層 22ⅹ = 三 氈四油防水層 20 厚水泥沙漿找平層 20ⅹ = 150 厚水泥蛭石保溫層 5ⅹ = 130 厚鋼筋混凝土板 25ⅹ = V 型輕鋼龍骨吊頂 合計(jì) 標(biāo)準(zhǔn)層樓面： 瓷磚地面（包括水泥粗砂打底） 100 厚鋼筋混凝土板 25ⅹ = V 型輕鋼龍骨吊頂 合計(jì) kn/m2 2）屋面及樓面可變荷載標(biāo)準(zhǔn)值 不上人屋面均布活荷載標(biāo)準(zhǔn)值 kn/m2 樓面活荷載標(biāo)準(zhǔn)值 kn/m2 屋面雪荷載標(biāo)準(zhǔn)值 sk=? rⅹ s0=ⅹ = kn/m2 式中 ? r 為屋面積雪分布系數(shù)，取 。框架 剪力墻結(jié)構(gòu)體系中的框架，可采用剛框架，也可采用鋼筋混凝土框架。輸入荷載進(jìn)行樓層組裝。雙向板的計(jì)算采用彈性分析法。 結(jié)構(gòu)設(shè)計(jì)時(shí)，要考慮可能出現(xiàn)的各種荷載的最大值和其同時(shí)作用在結(jié)構(gòu)上產(chǎn)生的綜合效應(yīng)。 荷載布置時(shí)可考慮可能產(chǎn)生的最不利內(nèi)力 1） 豎向活荷載的 布置，按最不利布置方式進(jìn)行內(nèi)力計(jì)算。六 層建筑不設(shè)電梯。基礎(chǔ)荷載由上部結(jié)構(gòu)傳下來(lái)，可根據(jù)基礎(chǔ)荷載設(shè)計(jì)簡(jiǎn)圖進(jìn)行基礎(chǔ)配筋計(jì)算。 32 2）建筑的立面形狀及其抗側(cè)力構(gòu)件的布置宜簡(jiǎn)單，規(guī)則、對(duì)稱，結(jié)構(gòu)的側(cè)向剛度和水平承載力沿高度均勻變化，自上而下逐漸減小，避免出現(xiàn)突變。 3， 強(qiáng)剪弱彎 —— 框架梁、柱的截面尺寸滿足《抗規(guī)》第 條的要求，框架梁端截面和框架柱的剪力設(shè)計(jì)值分別符合《抗規(guī)》第 、 條和第 到 條的要求，使梁柱的彎曲破壞先于剪切破壞。由于框架 剪力墻結(jié)構(gòu)體系中剪力墻是主要抗側(cè)力構(gòu)件，框架居于次要地位，因此在相同的設(shè)防烈度和結(jié)構(gòu)高度時(shí)，框架 剪力墻結(jié)構(gòu)中框架的抗震等級(jí)要求比純框架結(jié)構(gòu)體系的為低；框架 剪力墻結(jié)構(gòu)中剪力墻的抗震等級(jí)要求比純剪力墻結(jié)構(gòu)體系的為高；在同一框架 剪力墻結(jié)構(gòu)體系中，剪力墻的抗震等級(jí)要求比框架的為高。整個(gè)畢業(yè)設(shè)計(jì)中，專業(yè)知識(shí)的掌握和自學(xué)能力都進(jìn)行了全面的考驗(yàn)。 37 AN OVERVIEW OF STRUCTURES Definitions are a timehonored way of opening any book. A simple definition of a structure in a building context is that a structure is a device for channeling loads that result from the use and/or presence of the building to the ground. Important in the study of structures are many widely varying concerns. The study of structures certainly involves defining what a force itself is, since this familiar term represents a fairly abstract concept. The study of structures in a building context also involves dealing with much broader issues of space and dimensionality. The words size, scale, form, proportion, and morphology are all terms monly found in the vocabulary of a structural designer. As a way of getting into the study of structures, it is useful to reconsider the first definition of a structure given above. Although valuable in the sense that it defines the purpose of a structure, the original definition unfortunately provides no insight into the makeup or characteristics of a structure: What is this device that channels loads to the ground? To adopt the plex and exacting style of a dictionary writer, a structure could be defined as a physical entity having a unitary character that can be conceived of as an anization of positioned constituent elements in space in which the character of the whole dominates the interrelationship of the parts. Its purpose would be defined as before. Although it might be very hard to believe, a contorted and relatively abstract definition of this type which is almost laughably academic in tone actually has some merit. It first states that a structure is a real physical object, not an abstract idea or interesting issue. A structure is not a matter of debate, it is something that is built. The implication is that a structure must be dealt with accordingly. Merely verbally postulating that a structure can carry a certain type of load or function in a certain way, for example, is inadequate. A physical device must be provided for acplishing the desired ends that conforms to basic principles governing the behavior of physical objects. Devising such a structure is the role of the designer. The expanded definition also makes the point that a structure functions as a 38 whole. This is a point of fundamental importance and one easily fotten when confronted with a typical building posed of a seemingly endless array of individual beams and columns. There is in such cases an immediate tendency to think of the structure only as an assembly of individual small elements in which each element performs a separate function. In actuality, all structures are, and must be, primarily designed to function as a whole unit and only secondarily as an array of discrete elements. In line with the latter part of the expanded definition, the elements are invariably so positioned and interrelated as to enable the overall structure to function as a whole in carrying either vertically or horizontally acting loads to the ground. No matter how some individual elements are located and attached to one another, if the resultant configuration and interrelation of all elements does not function as a whole unit in channeling loads of all anticipated types to the ground, the configuration cannot be said to be a structure. The referen