土木外文翻譯----建筑結構的造價

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>　　建筑結構的造價</b></p><p><b>　　前言</b></p><p>　　建筑物的結構設計是一個相當復雜的過程，不但要處理很多物質因素，還要考慮諸多非物質方面的因素。如果建筑物的結構

71、形式對空間組織和美化環(huán)境的設計能夠起到舉足輕重的影響，那么它就是一個相當重要的物理因素，就應當采用分階段的設計方法。</p><p>　　建筑物的經(jīng)濟問題是一個主要的非物質因素，在最終的設計中應予以重視。對一個具有創(chuàng)造性的設計而言，從某方面來說考慮經(jīng)濟性往往是一種制約，但這也并非是絕對的。如果事先清楚結構設計及施工組織方案與實現(xiàn)他們的造價之間的關系，那么創(chuàng)造性是同樣可以實現(xiàn)的。調查表明，大多具有創(chuàng)造性的設計是在有

72、競爭性的投標中獲得成功的，而不是因為業(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)造性的設計應該具有很強的經(jīng)濟性。特別是今天，人們應該逐漸認識到，高雅和經(jīng)濟其實是一個可以統(tǒng)一的概念。</p><p>　　因此，本文列舉一些造價分析參數(shù)的簡單解釋，以及設計人員在他們的結構設計中考慮經(jīng)濟因素經(jīng)常采用的一些設計手法。</p><p>　　結構造價是通過其在建筑物總造價

73、中所占的百分比來衡量的?；蛘哒f，由于結構工程只是一個項目總造價的一部分，因此還要考慮附加費用如地價（10%~20%）、籌資利息（100%~200%）、稅金及維修費（20%左右）。不過上面這些因素都不在本文的討論范圍之內，文章將重點介紹工程造價。</p><p>　　平均來說，單純的結構造價大約占建筑物總造價25%。按照慣例，建筑物的結構造價和所謂的建筑造價是分開的。一般說來，所謂的建筑造價，往往是指那些與建筑的結

74、構強度和物理完整性無關的因素。</p><p>　　“基本服務設施費”組成了第三類工程費用，主要是指機械供給、電器設備以及其他一些服務體系費用等。一般說來，這部分費用大概占建筑物總費用的15%~30%，這主要取決于建筑物的類型。機械和電氣費用，主要是指空調系統(tǒng)費用以及其他諸如管道系統(tǒng)、通訊、照明及動力設備等服務設施。</p><p>　　在這種造價分類中非常顯著的一點是，一個建筑物的設計方

75、案的總體費用，應該有45%~60%分配給建筑因素。但現(xiàn)在這種狀況正在迅速改變，因為高利率以及資金的缺乏，現(xiàn)在大多業(yè)主更傾向于節(jié)約型設計。因此，設計者可以考慮以下兩條途徑，他們可以直接影響建筑物的工程造價。</p><p>　　第一個節(jié)約開支的途徑是這樣來考慮的，即凡是那些建筑問題和結構問題能夠同時解決的地方往往有著很強的經(jīng)濟潛力。由于目前大多人都不愿將建筑物費用的大部分用于純粹建筑設計，這種方法就顯得尤為重要，也

76、會節(jié)省一部分非結構預算，這一經(jīng)費可用于一些本來會被削減掉的建筑需求。第二種節(jié)約開支的途徑，則是設計人員在設計過程中綜合考慮服務設施和結構體系，盡力提出一個能夠解決房屋設計和施工難題的總建筑方案。</p><p>　　承包商通常會用不同的方式做出工程項目的最終報價。他們往往將其分為場地材料費、每一個施工過程中的勞動力資源費、工程所需購買、租借的裝備費、經(jīng)營管理費以及利潤。建筑師以及工程師很少考慮的像上面所述的那么精

77、確，但是頭腦中應該有一個清楚的概念，那就是一項結構工程的實際造價最終使用什么方法定價以及承包商又是怎樣標價的。</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。并進一步闡述對建筑物造價進行粗略估計時用到的百分比估價、平方英尺估價和單位體積估價。</p><p><b>　　百分比估價</b&g

78、t;</p><p>　　建筑物的類型將決定結構費用以和他費用所占的白分比范圍。正如所希望的，裝飾性或者標志性較強的建筑物的結構造價在總體造價中所占的比重相對較低。一般而言，結構造價所占的百分比可低至工程總造價的10%~15%，這是因為更多的錢被用到那些非結構費用上了。這又一次說明“裝飾”部分是與基本的結構要求無關的。然而對于一些諸如教堂類的綜合性標志建筑物，對其結構體系的造價相對較高，其百分比可達到15%~20

79、%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，由于內部隔墻、天花板、管道設備系統(tǒng)以及裝修部分要求較低，其結構造價在工程總體造價中所占的比例往往能達到60%~70%，有時甚至可達80%。</p><p>　　對于一些中等高度（5~10層）的辦公樓或住宅樓，其結構造價在總體造價中所占的比例，大約維持在25%這一中間值；而對于一

80、些低矮且跨度小的商業(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，其結構造價將占總造價15%~20%。</p><p>　　而一些特殊用途的建筑，如實驗室和醫(yī)院，則另當別論。他們需要較大的跨度以及高要求的機械設備。這就導致總體造價大部分將被用于服務費用（大約30%~50%）,而單純的結構造價約占20%。對于15層或者以上的高層辦公樓以及大跨度（約50~60英尺）建筑物，其結構造價在總體造價中

81、將占較高的百分比（約30%~35%），而服務費用約占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計平均效益的尺度。例如，如果一個較低的小跨度且不具備紀念價值的建筑物，僅僅結構造價投標就為30%的話，那么可以肯定這個結構設計是相當不經(jīng)濟的。另一方面，建筑師應該注意到的一個容易混淆的事實就是，經(jīng)濟投標往往取決于設計者和承包人對設計的理解及施工的實際能力，能力強

82、就能提供一個較低的投標。創(chuàng)造性設計受限往往是因為設計者或承包商在經(jīng)驗、想象力等方面的匱乏。如果承包者沒有把握，那么它就會加大投資，以防可能遇到的意外風險。因此要使有創(chuàng)造性的設計在投標時具有競爭力，作為一名建筑師它應能夠洞察工程潛力所在。至少建筑師應該盡可能地與想象力豐富的結構工程師、承包商甚至制造商密切配合。相反，即使對于最為普通的建筑設計，如果僅僅靠設計手冊，是很難取得經(jīng)濟效益的。效率離不開專業(yè)知識，而最為重要的是想象力，這一點在面對

83、一個不太熟悉的項目是尤為重要的。</p><p>　　如果建筑物結構設計具有中等（或標準）的效益時，前面所提到的百分比就對建筑物總造價估算有著很大的幫助。例如，如果一座辦公樓總體造價500萬美元，其中有25%是結構造價的標準，那么這一工程結構體系造價就不能超過125萬美元。若設計很合理，比如是按上述的中等效益設計估算造價的80%時，那么就有25萬美元，也就是5%的總體建筑費用被省下來。如果這500萬資金已經(jīng)到位，

84、那么節(jié)省下的25萬美元就可用于其他的經(jīng)濟開支。</p><p>　　上面所有闡述表明，結構設計和建筑整體設計（機械和電器）的創(chuàng)造性結合的概念，將有助于減少單純的結構造價，或在相同造價下提供更多的建筑費用。這樣，設計成功的程度將取決于設計者的專業(yè)知識、靈活性以及設計者和承包人之間的密切合作。</p><p>　　上面討論的僅僅是提供一種關于建筑總體造價的全面視圖，下面的部分將提供對建筑的結構

85、造價進行估價的方法。有兩種可供選擇的方法將用來進行結構造價的近似估計：其一是根據(jù)單位平方英尺建筑面積來進行估價；另一種則是根據(jù)所用的結構材料體積進行估價。參考上面所提到的結構造價標準，結構估價有助于對建筑的總體造價進行大概的了解。當然，這樣得到的只是一個粗略的估價，但卻會使設計負責人員對實際設計中經(jīng)常要面對的經(jīng)濟問題有所了解。至少，這些將有助于對可供選擇的結構體系的相對成本效益進行對比。</p><p><

86、b>　　平方英尺估價</b></p><p>　　如前所述，在一個特定的時期和地區(qū)，是可以根據(jù)相似工程的平均造價，來經(jīng)驗地確定準平方英尺造價系數(shù)。設計者和承包人有效的利用材料和勞動力的能力不同，會導致不同平均水平的經(jīng)濟效益。</p><p>　　對于“標準”的結構體系而言，每平方英尺的造價為10~16美元，例如，普通的辦公樓平均水平在12~16美元之間，而住宅型建筑的范圍

87、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，而上限則適用于較大跨度及中等高度的建筑。</p><p>　　與普通的住宅性建筑相似，普通工業(yè)建筑結構簡單，通常每平方英尺的造價為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，設計和安裝的簡單化，可以彌補工業(yè)建筑因大跨度和重載所造成的額外造價。</p>&

88、lt;p>　　當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雜程度、跨度超長的程度、特殊的荷載和地震條件等。例如，位于舊金山的Crown Zellerbach 銀行和辦公樓就是個例子，結構造價相當高。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。在那個時期，這樣的設計是非同尋常的，正是因為其特殊的用途及標志性，它才被允許以建筑物各方面都高出同類建筑物的平均水平

89、的造價進行建造。因此，其結構造價在總體造價中的比重也比普通建筑物高很多。</p><p>　　現(xiàn)在將進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，結構造價將會提高大約20~30%。</p><p>　　工業(yè)建筑中較大的荷載也無形中

90、提高了建筑物的結構造價。如果一個工業(yè)建筑的荷載增加到每平方米500磅（大約2~3倍）的話，其結構造價也將提高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，不管是鋼結構還是預應力混凝土，其現(xiàn)代設計者經(jīng)濟的限值都是150英尺。盡管鋼結構空間框架常大于150英尺，其制造費用也將大大增加。</p><p>　　無論如何，長跨度體系都有其特

91、殊性，它可能較多，也可能較少的影響總體建筑造價時，對于特殊的建筑物，其結構造價將隨著設計的不同而明顯地改變 。結構形式越特殊，由設計知識、設計的創(chuàng)造性以及施工技術所決定的造價節(jié)儉潛力就越大。</p><p><b>　　體積度量估價</b></p><p>　　初看起來，一個建筑師不善于精確地估計建筑過程中所用到的材料體積，如果要得到更高的精度，可以通過工程中所用到的

92、材料體積來估計造價。雖然進展非常緩慢，但通過努力學習后，是可以實現(xiàn)這一估計的。</p><p>　　體積度量估價，是通過制定結構系統(tǒng)中需要的以磅或噸記的鋼材、立方體的鋼筋或預應力混凝土的市場價格來實現(xiàn)的。對于這樣一個初步估計，沒有必要去深究它的詳細造價。例如，混凝土的現(xiàn)澆造價將包括模板、腳手架、鋼筋、勞動力等費用和間接費用。鋼結構則包括構件制作及安裝的費用。</p><p>　　以重量計的

93、建筑鋼材的市場價格，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。而復雜的結構體系需要較多的切割和焊接（如復雜的鋼桁架或空間框架設計），因而其鋼材價格可達0.7美元甚至更高。對于標準的高層建筑設計，每平方米大概將由20~30磅鋼材，這是設計人員不希望超過的量值。而每平方米低于20磅的設計，則需要很強的創(chuàng)造力以及建筑物設計和結構設計上完美的結合，其可稱得

94、上是一個真正的成就。</p><p>　　混凝土的價格是以體積計量的，其范圍從簡易的每立方米150美元的現(xiàn)澆鋼筋混凝土工程，到非常昂貴的每立方米300美元的小批量所謂預制和預應力工程不等。出現(xiàn)如此大的價格范圍。是因為影響因素較復雜，包括預制構件的形狀、安裝的難易和生產總量。</p><p>　　模板通常是現(xiàn)場澆筑混凝土構件的決定性因素，因此，為得到每立方米150美元的價格，需要采用最簡單的

95、體系方可，例如需要很少的模板加工量并可多次使用模板。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，價格由每立方米180美元上升到每立方米300美元。在發(fā)達國家，由于較高的勞動力費用，導致較高的模板造價，這就迫使人們采用最簡單的和大批量可重復使用的結構構件來實現(xiàn)造價的削減。當現(xiàn)場澆筑價格開始接近每立方米240美元時，就應該考慮大批量生產的預制和預應力構件的使用，這樣將會減少造價和縮短工期。后者將會因為公開支附費用的降低，使

96、承包商快速贏利。</p><p>　　總的來說，每平方米現(xiàn)場澆筑混凝土的標準價格將從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雜程度的后張預應力工程。這樣一個價格范圍相對較大，任何忽略了上述影響因素的估價，都將是不準確的。</p><p><b>　　總結</b></p><p>　　建筑物的成本估計及節(jié)約設計