建筑結(jié)構(gòu)成本外文翻譯

1、<p>　　The Cost of Building Structure</p><p>　　1. Introduction</p><p>　　The art of architectural design was characterized as one of dealing comprehensively with a complex set of physical and

2、 nonphysical design determinants. Structural considerations were cast as important physical determinants that should be dealt with in a hierarchical fashion if they are to have a significant impact on spatial organizatio

3、n and environmental control design thinking.</p><p>　　The economical aspect of building represents a nonphysical structural consideration that, in final analysis, must also be considered important. Cost cons

4、iderations are in certain ways a constraint to creative design. But this need not be so. If something is known of the relationship between structural and constructive design options and their cost of implementation, it i

5、s reasonable to believe that creativity can be enhanced. This has been confirmed by the authors’ observation that most enhanced</p><p>　　Therefore, in this chapter we will set forth a brief explanation of th

6、e parameters of cost analysis and the means by which designers may evaluate the overall economic implications of their structural and architectural design thinking.</p><p>　　The cost of structure alone can b

7、e measured relative to the total cost of building construction. Or, since the total construction cost is but a part of a total project cost, one could include additional consideration for land(10～20percent),finance and i

8、nterest(100～200 percent),taxes and maintenance costs (on the order of20 percent).But a discussion of these so-called architectural costs is beyond the scope of this book, and we will focus on the cost of construction onl

9、y.</p><p>　　On the average, purely structural costs account for about 25 percent of total construction costs, This is so because it has been traditional to discriminate between purely structural and other so

10、-called architectural costs of construction. Thus, in tradition we find that architectural costs have been taken to be those that are not necessary for the structural strength and physical integrity of a building design.

11、</p><p>　　“Essential services” forms a third construction cost category and refers to the provision of mechanical and electrical equipment and other service systems. On the average, these service costs accou

12、nt for some 15 to 30 percent of the total construction cost, depending on the type of building. Mechanical and electrical refers to the cost of providing for air-conditioning equipment and he means on air distribution as

13、 well as other services, such as plumbing, communications, and electrical light and</p><p>　　The salient point is that this breakdown of costs suggests that, up to now, an average of about 45 to 60 percent o

14、f the total cost of constructing a typical design solution could be considered as architectural. But this picture is rapidly changing. With high interest costs and a scarcity of capital, client groups are demanding leane

15、r designs. Therefore, one may conclude that there are two approaches the designer may take towards influencing the construction cost of building.</p><p>　　The first approach to cost efficiency is to consider

16、 that wherever architectural and structural solutions can be achieved simultaneously, a potential for economy is evident. Since current trends indicate a reluctance to allocate large portions of a construction budget to

17、purely architectural costs, this approach seems a logical necessity. But, even where money is available, any use of structure to play a basic architectural role will allow the nonstructural budget to be applied to fulfil

18、l other </p><p>　　The final pricing of a project by the constructor or contractor usually takes a different form. The costs are broken down into (1) cost of materials brought to the site, (2)cost of labor in

19、volved in every phase of the construction process, (3)cost of equipment purchased or rented for the project, (4)cost of management and overhead, and(5) profit. The architect or engineer seldom follows such an accurate pa

20、th but should perhaps keep in mind how the actual cost of a structure is finally priced and</p><p>　　Thus, the percent averages stated above are obviously crude, but they can suffice to introduce the nature

21、of the cost picture. The following sections will discuss the range of these averages and then proceed to a discussion of square footage costs and volume-based estimates for use in rough approximation of the cost of build

22、ing a structural system.</p><p>　　2. Percentage Estimates</p><p>　　The type of building project may indicate the range of percentages that can be allocated to structural and other costs. As migh

23、t be expected, highly decorative or symbolic buildings would normally demand the lowest percentage of structural costs as compared to total construction cost. In this case the structural costs might drop to 10～15percent

24、of the total building cost because more money is allocated to the so-called architectural costs. Once again this implies that the symbolic components are</p><p>　　At the other end of the cost scale are the v

25、ery simple and nonsymbolic industrial buildings, such as warehouses and garages. In these cases, the nonstructural systems, such as interior partition walls and ceilings, as will as mechanical systems, are normally minim

26、al, as is decoration, and therefore the structural costs can account for60 to 70 percent, even 80 percent of the total cost of construction.</p><p>　　Buildings such as medium-rise office and apartment buildi

27、ngs(5～10 stories)occupy the median position on a cost scale at about 25 percent for structure. Low and short-span buildings for commerce and housing, say, of three or four stories and with spans of some 20 or 30 ft and s

28、imple erection requirements, will yield structural costs of 15～20 percent of total building cost.</p><p>　　Special-performance buildings, such as laboratories and hospitals, represent another category. They

29、can require long spans and a more than average portion of the total costs will be allocated to services (i.e., 30～50 percent), with about 20 percent going for the purely structural costs. Tall office building (15 stories

30、 or more) and/or long-span buildings (say, 50 to 60 ft) can require a higher percentage for structural costs (about 30to 35percent of the total construction costs),with about 30 to</p><p>　　In my case, these

31、 percentages are typical and can be considered as a measure of average efficiency in design of buildings. For example, if a low, short-span and nonmonumental building were to be bid at 30 percent for the structure alone,

32、 one could assume that the structural design may be comparatively uneconomical. On the other hand, the architect should be aware of the confusing fact that economical bids depend on the practical ability of both the desi

33、gner and the contractor to interpret the de</p><p>　　The foregoing percentages can be helpful in approximating total construction costs if the assumption is made that structural design is at least of average

34、 (of typical) efficiency. For example, if a total office building construction cost budget is ﹩5,000,000,and 25 percent is the “standard” to be used for structure, a projected structural system should cost no more than ﹩

35、1,250,000.If a very efficient design were realized, say, at 80 percent of what would be given by the “average” efficient desig</p><p>　　All this suggests that creative integration of structural (and mechanic

36、al and electrical) design with the total architectural design concept can result in either a reduction in purely construction design concept can result in either a reduction in purely construction costs or more architect

37、ure for the same cost. Thus, the degree of success possible depends on knowledge, cleverness, and insightful collaboration of the designers and contractors.</p><p>　　The above discussion is only meant to giv

38、e the reader an overall perspective on total construction costs. The following sections will now furnish the means for estimating the cost of structure alone. Two alternative means will be provided for making an approxim

39、ate structural cost estimate: one on a square foot of building basis, and another on volumes of structural materials used. Such costs can then be used to get a rough idea of total cost by referring to the “standards” for

40、 efficient design g</p><p>　　3. Square-foot Estimating</p><p>　　As before, it is possible to empirically determine a “standard” per-square-foot cost factor based on the average of costs for simi

41、lar construction at a given place and time. more-or-less efficient designs are possible, depending on the ability of the designer and contractor to use materials and labor efficiently, and vary from the average.</p>

42、;<p>　　The range of square-foot costs for “normal” structural systems is ﹩10 to ﹩16 psf. For example, typical office buildings average between ﹩12 and ﹩16 psf, and apartment-type structures range from ﹩10 to ﹩14.I

43、n each case, the lower part of the range refers to short spans and low buildings, whereas the upper portion refers to longer spans and moderately tall buildings.</p><p>　　Ordinary industrial structures are s

44、imple and normally produce square-foot costs ranging from ﹩10 to ﹩14,as with the more typical apartment building. Although the spans for industrial structures are generally longer than those for apartment buildings, and

45、the loads heavier, they commonly have fewer complexities as well as fewer interior walls, partitions, ceiling requirements, and they are not tall. In other words, simplicity of design and erection can offset the addition

46、al cost for longer span </p><p>　　Of course there are exceptions to these averages. The limits of variation depend on a system’s complexity, span length over “normal” and special loading or foundation condit

47、ions. For example, the Crown Zellerbach high-rise bank and office building in San Francisco is an exception, since its structural costs were unusually high. However, in this case, the use of 60 ft steel spans and fr

48、ee-standing columns at the bottom, which carry the considerable earthquake loading, as well as the special </p><p>　　The effect of spans longer than normal can be further illustrated. The “usual” floor span

49、range is as follows: for apartment buildings,16 to 25 ft; for office buildings,20 to 30 ft; for industrial buildings,25 to 30 ft loaded heavily at 200 to 300 psf; and garage-type structures span,50 to 60 ft, carrying rel

50、atively light(50～75 psf) loads(i.e., similar to those for apartment and office structures).where these spans are doubled, the structural costs can be expected to rise about 20 to 30 percent.</p><p>　　To incr

51、eased loading in the case of industrial buildings offers another insight into the dependency of cost estimates on “usual” standards. If the loading in an industrial building were to be increased to 500psf(i.e., two or th

52、ree times), the additional structural cost would be on the order of another 20 to 30 percent.</p><p>　　The reference in the above cases is for floor systems. For roofs using efficient orthotropic (flat) syst

53、ems, contemporary limits for economical design appear to be on the order of 150 ft, whether of steel or prestressed concrete. Although space- frames are often used for steel or prestressed concrete. Although space-fram

54、es are often used for steel spans over 150 ft the fabrication costs begin to raise considerably.</p><p>　　At any rate, it should be recognized that very long-span subsystems are special cases and can in them

55、selves have a great or small effect on is added, structural costs for special buildings can vary greatly from design to design. The more special the form, the more that design knowledge and creativity, as well as constru

56、ction skill, will determine the potential for achieving cost efficiency.</p><p>　　4. Volume-Based Estimates</p><p>　　When more accuracy is desired, estimates of costs can be based on the volume

57、of materials used to do a job. At first glance it might seem that the architect would be ill equipped to estimate the volume of material required in construction with any accuracy, and much less speed. But it is possible

58、, with a moderate learning effort, to achieve some capability for making such estimates.</p><p>　　Volume-based estimates are given by assigning in-place value to the pounds or tons of steel, or the cubic yar

59、ds of reinforced or prestressed concrete required to build a structural system. For such a preliminary estimate, one does not need to itemize detailed costs. For example, in-place concrete costs include the cost of formi

60、ng, falsework, reinforcing steel, labor, and overhead. Steel includes fabrication and erection of components.</p><p>　　Costs of structural steel as measured by weight range from ﹩0.50 to ﹩0.70 per pou

61、nd in place for building construction. For low-rise buildings, one can use stock wide-flange structural members that require minimum fabrication, and the cost could be as bow as ﹩0.50 per pound. More complicated systems

62、requiring much cutting and welding(such as a complicated steel truss or space-frame design) can go to ﹩0.70 per pound and beyond. For standard tall building designs (say, exceeding 20 stories),there </p><p>

63、　　Concrete costs are volumetric and should range from an in-place low of ﹩150 per cu yd for very simple reinforced concrete work to ﹩300 per cu yd for expensive small quantity precast and prestressed work. This large ran

64、ge is due to the fact that the contributing variables are more complicated, depending upon the shape of the precise components, the erection problems, and the total quantity produced.</p><p>　　Form work is g

65、enerally the controlling factor for any cast-in-place concrete work. Therefore, to achieve a cost of ﹩150 per cu yd, only the simplest of systems can be used, such as flat slabs that require little cutting and much reuse

66、 of forms. Where any beams are introduced that require special forms and difficulty in placement of concrete and steel bars, the range begins at ﹩180 per cu yd and goes up to ﹩300.Since, in a developed country, high labo

67、r costs account for high forming costs, this r</p><p>　　To summarize, the range of cost per cubic yard of standard types of poured-in-place concrete work will average from $150 to $250, the minimum being for

68、 simple reinforced work and the maximum for moderately complicated post tensioned work. This range is large and any estimate that ignores the effect of variables above will be commensurately inaccurate. </p><p

69、><b>　　5.Summary</b></p><p>　　The estimate and economical design of structure building are important and essential work, which should be valued by all architects and engineers and others. Bette

70、r you do it, more profit you will receive from it!</p><p><b>　　建筑結(jié)構(gòu)的成本</b></p><p><b>　　前言</b></p><p>　　眾所周知，建筑物的結(jié)構(gòu)設(shè)計(jì)是一個(gè)相當(dāng)復(fù)雜的過程，其中既包含處理很多物質(zhì)因素，又考慮諸多非物質(zhì)方面的因素。如果

71、建筑物的結(jié)構(gòu)形式對空間組織和美化環(huán)境的設(shè)計(jì)起這句舉足輕重的影響，那么它就是一個(gè)相當(dāng)重要的物理因素，就應(yīng)當(dāng)采用分階段的設(shè)計(jì)方法。</p><p>　　對建筑物的經(jīng)濟(jì)考慮是一個(gè)主要的非物質(zhì)因素，在最終的設(shè)計(jì)中應(yīng)予以重視。對一個(gè)具有創(chuàng)造性的設(shè)計(jì)而言，經(jīng)濟(jì)考慮從某方面來說往往是一種制約，但這也并非是絕對的。如果事先清楚結(jié)構(gòu)設(shè)計(jì)及施工組織方案與實(shí)現(xiàn)他們的造價(jià)之間的關(guān)系，那么創(chuàng)造性是同樣可以實(shí)現(xiàn)的。調(diào)查表明，大多具有創(chuàng)造性的

72、設(shè)計(jì)是在有競爭性的投標(biāo)中獲得成功的，而不是因?yàn)闃I(yè)主非常富有。盡管后者被大肆炒作，卻很少使人信服。因此也可以說，真正具有創(chuàng)造性的設(shè)計(jì)因該具有很強(qiáng)的經(jīng)濟(jì)性。特別是今天，人們應(yīng)該逐漸認(rèn)識(shí)到，高雅和經(jīng)濟(jì)其實(shí)是一個(gè)可以統(tǒng)一的概念。</p><p>　　因此，本文列舉一些造價(jià)分析參數(shù)的簡單解釋，以及設(shè)計(jì)人員在他們的結(jié)構(gòu)設(shè)計(jì)中考慮經(jīng)濟(jì)因素是經(jīng)常采用的一些設(shè)計(jì)中考慮經(jīng)濟(jì)因素是經(jīng)常采用的一些設(shè)計(jì)手法。</p><

73、;p>　　結(jié)構(gòu)造價(jià)本身是通過其在建筑物總造價(jià)中所占的百分比來衡量的。或者說，由于工程只是一個(gè)項(xiàng)目總造價(jià)的一部分，因此還要考慮附加費(fèi)用如地價(jià)（10%~20%）、籌資利息（100%~200%）、稅金及維修費(fèi)（20%左右）。不過上面這些因素都不在本文的討論范圍之內(nèi)，文章將重點(diǎn)介紹工程造價(jià)。</p><p>　　平均來說，單純的結(jié)構(gòu)造價(jià)大約占建筑物總造價(jià)25%。按照慣例，建筑無的結(jié)構(gòu)造價(jià)和所謂的建筑造價(jià)是分開的。一

74、般說來，所謂的建筑造價(jià)，往往是指那些與建筑的結(jié)構(gòu)強(qiáng)度和物理完整性無關(guān)的因素。</p><p>　　“基本服務(wù)設(shè)施費(fèi)”組成了第三類工程費(fèi)用，主要是指機(jī)械供給、電器設(shè)備以及其他一些服務(wù)體系等費(fèi)用。一般說來，這部分費(fèi)用大概占建筑物總費(fèi)用的15%~30%，這主要取決于建筑無的類型。機(jī)械和電氣費(fèi)用，主要是指空調(diào)系統(tǒng)費(fèi)用以及其他諸如管道系統(tǒng)、通訊、照明及動(dòng)力設(shè)備等其他服務(wù)設(shè)施。</p><p>　　在

75、這一造價(jià)分類中非常顯著的一點(diǎn)是，一個(gè)典型的建筑物設(shè)計(jì)方案的總體費(fèi)用，應(yīng)該有45%~60%分配給建筑因素。但現(xiàn)在這種狀況正在迅速改變，因?yàn)楦呃室约百Y金的缺乏，現(xiàn)在大多業(yè)主更傾向于節(jié)約型設(shè)計(jì)。因此，設(shè)計(jì)者應(yīng)該考慮兩條途徑，他們可以直接影響建筑無的工程造價(jià)。</p><p>　　第一個(gè)節(jié)約開支的途徑可以這樣來考慮，即凡是那些建筑問題和結(jié)構(gòu)問題能夠同時(shí)解決的地方往往有著很強(qiáng)的經(jīng)濟(jì)潛力。由于目前大多設(shè)計(jì)都不愿將建筑物費(fèi)用

76、一大部分用于純粹建筑設(shè)計(jì)，這種方法就顯得尤為重要，也會(huì)節(jié)省一部分非結(jié)構(gòu)預(yù)算，這一經(jīng)費(fèi)可用于一些本會(huì)被削減掉的建筑需求。第二種節(jié)約開支的途徑，則是設(shè)計(jì)人員在設(shè)計(jì)過程中綜合考慮服務(wù)設(shè)施和結(jié)構(gòu)體系，盡力提出一個(gè)能夠解決房屋設(shè)計(jì)和施工難題的總建筑方案。</p><p>　　承包商通?；赜貌煌姆绞阶龀龉こ添?xiàng)目的最終報(bào)價(jià)。他們往往將其分為場地材料費(fèi)、每一個(gè)施工過程中的勞動(dòng)力資源費(fèi)、工程所需購買、租借的裝備費(fèi)、經(jīng)營管理費(fèi)以及

77、利潤。建筑師以及工程師很少考慮的像上面所述的那么精確，但是頭腦中應(yīng)該有一個(gè)清楚的概念，那就是一項(xiàng)結(jié)構(gòu)工程的實(shí)際造價(jià)最終使用什么方法定價(jià)以及承包商又是怎樣標(biāo)價(jià)的。</p><p>　　顯然，上面講到的百分比平均數(shù)有些粗略，但是它足以說明總體造價(jià)的組成情況了。下面的幾部分將討論這些平均數(shù)的范圍，并進(jìn)一步闡述在對建筑無的造價(jià)進(jìn)行粗略、近似估計(jì)時(shí)用到的平方英尺以及單位體積造價(jià)。</p><p>&

78、lt;b>　　百分比估價(jià)</b></p><p>　　建筑物的類型將決定結(jié)構(gòu)費(fèi)用以及其他費(fèi)用所占的白分比范圍。正如所希望的，裝飾性或者標(biāo)志性較強(qiáng)的建筑物的結(jié)構(gòu)造價(jià)在總體造價(jià)中所占的比重相對較低。一般而言，結(jié)構(gòu)造價(jià)所占的百分比可低至工程總造價(jià)的10%~15%，這是因?yàn)楦嗟腻X被用到那些非結(jié)構(gòu)費(fèi)用上了。這又一次說明“裝飾”部分是與基本的結(jié)構(gòu)要求無關(guān)的。然而對于一些諸如教堂類的綜合性標(biāo)志建筑物，對其結(jié)

79、構(gòu)體系的造價(jià)相對較高，其百分比可達(dá)到15%~20%或者更高。</p><p>　　與之相對的是一些諸如倉庫或者車庫之類簡易的和非象征性的工業(yè)建筑物，對于這種建筑，由于內(nèi)部隔墻、天花板、管道設(shè)備系統(tǒng)以及裝修部分要求較低，其結(jié)構(gòu)造價(jià)在工程總體造價(jià)中所占的比例往往能達(dá)到60%~70%，有時(shí)甚至可達(dá)80%。</p><p>　　對于一些中等高度（5~10層）得多層辦公樓或住宅樓，其結(jié)構(gòu)造價(jià)在總體造

80、價(jià)中所占的比例，大約維持在25%這一中間值；而對于一些低矮且跨據(jù)短的商業(yè)用房和住宅，大約3~4層高且跨度為20~30英尺以及簡單的豎向要求，其結(jié)構(gòu)造價(jià)將占總造價(jià)15%~20%。</p><p>　　而一些特殊用途的建筑，如實(shí)驗(yàn)室和醫(yī)院，則另當(dāng)別論。他們需要較大的跨度以及不一般要求高的機(jī)械裝備。這就導(dǎo)致總體造價(jià)得以大部分將被用于服務(wù)費(fèi)用（大約30%~50%）,而單純的結(jié)構(gòu)造價(jià)約占20%。對于15層或者以上的高層辦公

81、樓以及大跨度（約50~60英尺）建筑物，其結(jié)構(gòu)造價(jià)在總體造價(jià)中將占較高的百分比（約30%~35%），而服務(wù)費(fèi)用約占30%~40%。</p><p>　　在任何情況下這些百分比數(shù)據(jù)都是具有典型性的，并可作為衡量建筑物設(shè)計(jì)平均效益的尺度。例如，如果一個(gè)較低的小跨度且不具備紀(jì)念價(jià)值的建筑物，僅僅結(jié)構(gòu)造價(jià)投標(biāo)就為30%的話，那么可以肯定這個(gè)結(jié)構(gòu)設(shè)計(jì)是相當(dāng)不經(jīng)濟(jì)的。另一方面，建筑師應(yīng)該注意到的一個(gè)容易混淆的事實(shí)就是，經(jīng)濟(jì)投

82、標(biāo)往往取決于設(shè)計(jì)者和承包人的理解設(shè)計(jì)及施工要求的實(shí)際能力，能力強(qiáng)就能提供一個(gè)較低的投標(biāo)。創(chuàng)造性設(shè)計(jì)受限往往是因?yàn)樵O(shè)計(jì)者或承包商在經(jīng)驗(yàn)、想象力際交流方面的匱乏。如果承包者沒有把握，那么它就會(huì)加大投資，以防可能遇到的意外風(fēng)險(xiǎn)。因此要使有創(chuàng)造性的設(shè)計(jì)在投標(biāo)時(shí)具有競爭力，作為一名建筑師它應(yīng)能夠洞察工程潛力所在。至少建筑是應(yīng)該盡可能地與想象力豐富的結(jié)構(gòu)工程師、承包商甚至制造商驚醒密切配合。相反，即使對于最為普通的建筑設(shè)計(jì)，如果僅僅靠設(shè)計(jì)手冊，是很

83、難取得經(jīng)濟(jì)效益的。效率離不開專業(yè)知識(shí)，而最為重要的是想象力，這一點(diǎn)在面對一個(gè)不太熟悉的項(xiàng)目是尤為重要。</p><p>　　如果建筑物結(jié)構(gòu)設(shè)計(jì)至少具有中等（或標(biāo)準(zhǔn)）的效益時(shí)，前面所提到的百分比就對建筑物總造價(jià)估算有著很大的幫助。例如，如果一座辦公樓總體造價(jià)500萬美元，其中有25%時(shí)結(jié)構(gòu)造價(jià)的標(biāo)準(zhǔn)，那么這一工程結(jié)構(gòu)體系造價(jià)就不能超過125萬美元。若設(shè)計(jì)很合理，比如時(shí)按上述的中等效益設(shè)計(jì)估算造價(jià)的80%時(shí)，那么就有

84、25萬美元，也就是5%的總體建筑費(fèi)用被省下來。如果這500萬資金已經(jīng)到位，那么節(jié)省下的25萬美元就可用于其他的經(jīng)濟(jì)開支。</p><p>　　上面所有闡述表明，結(jié)構(gòu)設(shè)計(jì)和建筑整體設(shè)計(jì)（機(jī)械和電器）的創(chuàng)造性結(jié)合的概念，將有助于減少單純的結(jié)構(gòu)造價(jià)，或在相同造價(jià)下提供更多的建筑費(fèi)用。這樣，設(shè)計(jì)成功的程度將取決于設(shè)計(jì)者的專業(yè)知識(shí)、靈活性以及設(shè)計(jì)者和承包人之間有洞察力的合作，</p><p>　　上

85、面討論僅僅是提供一種關(guān)于建筑總體造價(jià)的全面視圖，下面的部分將提供對建筑的結(jié)構(gòu)造價(jià)進(jìn)行估價(jià)的方法。有兩種可供選擇的方法將用來進(jìn)行結(jié)構(gòu)造價(jià)的近似估價(jià)：其一是根據(jù)單位平方英尺建筑面積，另一種則是根據(jù)所用的結(jié)構(gòu)材料體積進(jìn)行估價(jià)。參考上面所提到的有效設(shè)計(jì)的結(jié)構(gòu)造價(jià)標(biāo)準(zhǔn)，最后的結(jié)構(gòu)估價(jià)有助于對建筑的總體造價(jià)驚醒大概的了解。當(dāng)然，這樣得到的只是一個(gè)粗略的估價(jià)，但卻會(huì)使設(shè)計(jì)負(fù)責(zé)人員對實(shí)際設(shè)計(jì)中經(jīng)常要面對的經(jīng)濟(jì)問題有所了解。至少，這些將有助于對可供選擇的

86、結(jié)構(gòu)體系的相對成本效益進(jìn)行對比。</p><p><b>　　平方英尺估算</b></p><p>　　如前所述，在一個(gè)特定的時(shí)期和地區(qū)，是可以根據(jù)相似工程的平均造價(jià)，來經(jīng)驗(yàn)地確定準(zhǔn)平方英尺造價(jià)系數(shù)。設(shè)計(jì)者和承包人有效的利用材料和勞動(dòng)力的能力不同，會(huì)導(dǎo)致不同平均水平的經(jīng)濟(jì)效率設(shè)計(jì)的。</p><p>　　對于“標(biāo)準(zhǔn)”的結(jié)構(gòu)體系而言，每平方英尺的

87、造價(jià)為10~16美元，例如，典型的辦公樓平均水平在12~16美元之間，而住宅型建筑的范圍則是10~14美元。對以上兩種情況，下限適用于短跨低矮的建筑，而上限則是用于較大跨度及中等高度的建筑。</p><p>　　如同典型的住宅性建筑，普通工業(yè)建筑結(jié)構(gòu)簡單，通常每平方英尺的造價(jià)為10~14美元。盡管工業(yè)建筑的跨度很大，且荷載較重，但他們的布局簡單，在內(nèi)墻、隔墻以及天花板方面的要求較少，且一般不高。換句話說，設(shè)計(jì)和安

88、裝的簡單化，可以彌補(bǔ)工業(yè)建筑因大跨度和重載所造成的額外造價(jià)。</p><p>　　當(dāng)然也存在著不同于平均水平的情況。變化的限度取決于體系的復(fù)雜程度、跨度超長的程度、特殊的荷載級地震條件等。例如，由于結(jié)構(gòu)造價(jià)相當(dāng)高，位于舊金山的Crown Zellerbach 銀行和辦公樓舊稱得上是個(gè)例外。60英尺跨度的鋼架以及底部用來承受地震荷載的自由支撐的柱子，連同舊金山糟糕的土壤狀況，都造成了較高的造價(jià)。在那個(gè)時(shí)期，這樣的設(shè)

89、計(jì)是非同尋常的，正是因?yàn)槠涮厥獾挠猛炯皹?biāo)志性，它才被允許以建筑物個(gè)方面都高出同類建筑物的平均水平的造價(jià)進(jìn)行建造。因此，其結(jié)構(gòu)造價(jià)在總體造價(jià)中的比重接近也普通建筑物。</p><p>　　現(xiàn)在將進(jìn)一步敘述超長跨度的影響。正?？缍鹊姆秶?guī)定為：住宅樓16~25英尺；辦公樓20~30英尺；工業(yè)建筑為25~30英尺，且每平方英尺承重200~300磅；車庫建筑為50~60英尺，且相對較輕。如果跨度增加一倍，結(jié)構(gòu)造價(jià)將會(huì)提高

90、大約20~30%。</p><p>　　工業(yè)建筑中較大的荷載也無形中提高了建筑物的結(jié)構(gòu)造價(jià)。如果一個(gè)工業(yè)建筑的荷載增加到每平方米500磅（大約2~3倍）的話，其結(jié)構(gòu)造價(jià)也將提高20~30%。</p><p>　　上面所述都是針對樓層系統(tǒng)而言的，對采用有效正交各向異性體系的公寓屋頂，不管是鋼還是預(yù)應(yīng)力混凝土的，其現(xiàn)代經(jīng)濟(jì)設(shè)計(jì)者的限值都是150英尺。盡管鋼結(jié)構(gòu)空間框架常大于150英尺，其制造費(fèi)

91、用也將大大增加。</p><p>　　無論如何，長跨度體系都有其特殊性，它可能較多，也可能較少的影響總體建筑造價(jià)時(shí)，對于特殊的建筑物，其結(jié)構(gòu)造價(jià)將隨著設(shè)計(jì)的不同而明顯地改變 。結(jié)構(gòu)形式越特殊，由設(shè)計(jì)知識(shí)、設(shè)計(jì)的創(chuàng)造性以及施工技術(shù)所決定的造價(jià)節(jié)儉潛力就越大。</p><p><b>　　體積度量估算 </b></p><p>　　初看起來，一個(gè)建

92、筑師不善于精確地估計(jì)建筑過程中所用到的材料體積，并如果要得到更高的精度，可以通過工程中所用到的材料體積來估計(jì)造價(jià)。且進(jìn)展會(huì)非常緩慢，但通過努力學(xué)習(xí)后，是可以實(shí)現(xiàn)這一估計(jì)的。</p><p>　　體積量度估價(jià)，是通過制定結(jié)構(gòu)系統(tǒng)中需要的以磅或噸記得鋼材、立方體的鋼筋或預(yù)應(yīng)力混凝土的現(xiàn)場價(jià)格來實(shí)現(xiàn)的。對于這樣一個(gè)初步估計(jì)，沒有必要去詳究它的詳細(xì)造價(jià)。例如，混凝土的現(xiàn)澆造價(jià)將包括模板、腳手架、鋼筋、勞動(dòng)力等費(fèi)用和間接費(fèi)

93、用。鋼結(jié)構(gòu)則包括構(gòu)件制作及安裝的費(fèi)用。</p><p>　　以重量計(jì)的建筑鋼材的現(xiàn)場價(jià)格，從每磅0.50美元到0.70美元不等。對于低層建筑，可采用現(xiàn)成的寬翼緣型鋼構(gòu)件，只需要極少的加工，因而成本可降低至每磅0.50美元。而復(fù)雜的結(jié)構(gòu)體系需要較多的切割和焊接（如復(fù)雜的鋼桁架或空間框架設(shè)計(jì)），因而其鋼材現(xiàn)場價(jià)格可達(dá)0.7美元甚至更高。對于標(biāo)準(zhǔn)的高層建筑設(shè)計(jì)，每平方米大概將由20~30磅鋼材，這是設(shè)計(jì)人員不希望超過的

94、量值。而每平方米低于20磅的設(shè)計(jì)，則需要很強(qiáng)的創(chuàng)造力以及建筑物設(shè)計(jì)和結(jié)構(gòu)設(shè)計(jì)上完美的結(jié)合，其可稱得上是一個(gè)真正的成就。</p><p>　　混凝土的價(jià)格是以體積計(jì)量的，其范圍從簡易的每立方碼150美元的現(xiàn)澆鋼筋混凝土工程，到非常昂貴的每立方碼300美元的小批量所謂預(yù)制和預(yù)應(yīng)力工程不等。出現(xiàn)如此大的價(jià)格范圍。是因?yàn)橛绊懸蛩剌^復(fù)雜，包括預(yù)制構(gòu)件的形狀、安裝的難易其生產(chǎn)總量。</p><p>　

95、　模板通常是現(xiàn)場澆制混凝土構(gòu)件的決定性因素，因此，為得到每立方碼150美元的價(jià)格，需要采用最簡單的體系方可，例如需要很少的模板加工量并可多次使用平板。一旦梁存在，就需要專門的模板，由于混凝土和鋼筋的放置上的困難，價(jià)格范圍每立方碼180美元上升到每立方碼300美元。在發(fā)達(dá)國家，由于較高的勞動(dòng)力費(fèi)用，導(dǎo)致較高的模板造價(jià)，這就迫使人們采用最簡單的和大批量可重復(fù)使用的結(jié)構(gòu)構(gòu)件來實(shí)現(xiàn)造價(jià)的削減。但現(xiàn)場澆制價(jià)格開始接近每立方碼240美元時(shí)，就應(yīng)該考

96、慮大批量生產(chǎn)的預(yù)制和預(yù)應(yīng)力構(gòu)件的使用，這樣將會(huì)減少造價(jià)和縮短工期。后者將會(huì)因?yàn)闀r(shí)公開支費(fèi)用的降低，是承包商快速贏利。</p><p>　　總的來說，每平方碼現(xiàn)場澆筑混凝土的標(biāo)準(zhǔn)價(jià)格將從150美元~250美元不等，其下限適用于簡單混凝土工程，而上限則適用于中等復(fù)雜程度的后張預(yù)應(yīng)力工程。這樣一個(gè)價(jià)格范圍相對較大，任何忽略了上述影響因素的估價(jià)，都將是不準(zhǔn)確的。</p><p><b>