土木工程外文翻译-建筑结构的成本

The Cost of Building Structure 1. Introduction The art of architectural design was characterized as one of dealing comprehensively with a complex set of physical and 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 organization and environmental control design thinking. The economical aspect of building represents a nonphysical structural consideration that, in final analysis, must also be considered important. Cost considerations 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 is reasonable to believe that creativity can be enhanced. This has been confirmed by the authors’ observation that most enhanced. This has been confirmed by the authors’ observation that most creative design innovations succeed under competitive bidding and not because of unusual owner affluence as the few publicized cases of extravagance might lead one to believe. One could even say that a designer who is truly creative will produce architectural excellence within the constraints of economy. Especially today, we find that there is a need to recognize that elegance and economy can become synonymous concepts. Therefore, in this chapter we will set forth a brief explanation of the parameters of cost analysis and the means by which designers may evaluate the overall economic implications of their structural and architectural design thinking. The cost of structure alone can be 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 interest(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 only. 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-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. “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 account 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 well as other services, such as plumbing, communications, and electrical light and power. The salient point is that this breakdown of costs suggests that, up to now, an average of about 45 to 60 percent of 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 leaner designs. Therefore, one may conclude that there are two approaches the designer may take towards influencing the construction cost of building. The first approach to cost efficiency is to consider 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 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 fulfill other architectural needs that might normally have to be applied to fulfill other architectural needs that might normally have to be cut back. The second approach achieves economy through an integration of service and structural subsystems to round out one’s effort to produce a total architectural solution to a building design problem. 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 involved 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 path but should perhaps keep in mind how the actual cost of a structure is finally priced and made up. Thus, the percent averages stated above are obviously crude, but they can suffice to introduce the nature 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 building a structural system. 2. Percentage Estimates The type of building project may indicate the range of percentages that can be allocated to structural and other costs. As might 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 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 conceived independent of basic structural requirements. However, where structure and symbolism are more-or-less synthesized, as with a church or Cathedral, the structural system cost can be expected to be somewhat higher, say, 15and20 percent (or more). At the other end of the cost scale are the very 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 minimal, as is decoration, and therefore the structural costs can account for60 to 70 percent, even 80 percent of the total cost of construction. Buildings such as medium-rise office and apartment buildings(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 simple erection requirements, will yield structural costs of 15～20 percent of total building cost. Special-performance buildings, such as laboratories and hospitals, represent another category. They 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 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 40 percent allocated to services. In my case, these 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, 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 designer and the contractor to interpret the design and construction requirements so that a low bid will ensue. Progress in structural design is often limited more by the designer’s or contractor’ slack of experience, imagination, and absence of communication than by the idea of the design. If a contractor is uncertain, he will add costs to hedge the risk he will be taking. It is for this reason that both the architect and the engineer should be well-versed in the area of construction potentials if innovative designs ate to be competitively bid. At the least the architect must be capable of working closely with imaginative structural engineers, contractors and even fabricators wherever possible even if the architecture is very ordinary. Efficiency always requires knowledge and above all imagination, and these are essential when designs are unfamiliar. The foregoing percentages can be helpful in approximating total construction costs if the assumption is made that structural design is at least of average (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 ﹩1,250,000.If a very efficient design were realized, say, at 80 percent of what would be given by the “average” efficient design estimate stated above the savings,(20 percent),would then be﹩250,000 or 5 percent of total construction costs ﹩5,000,000.If the ﹩5,000,000 figure is committed, then the savings of ﹩250,000 could be applied to expand the budget for “other” costs. All this suggests that creative integration of structural (and mechanical 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 architecture for the same cost. Thus, the degree of success possible depends on knowledge, cleverness, and insightful collaboration of the designers and contractors. The above discussion is only meant to give 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 approximate 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 efficient design given above. At best, this will be a crude measure, but it is hoped that the reader will find that it makes him somewhat familiar with the type of real economic problems that responsible designers must deal with. At the least, this capability will be useful in comparing alternative systems for the purpose of determining their relative cost efficiency. 3. Square-foot Estimating As before, it is possible to empirically determine a “standard” per-square-foot cost factor based on the average of costs for similar 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. 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.In 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. Ordinary industrial structures are simple 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 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 additional cost for longer span lengths and heavier loads in industrial buildings. 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 conditions. 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 free-standing columns at the bottom, which carry the considerable earthquake loading, as well as the special foundation associated with the poor San Francisco soil conditions, contributed to the exceptionally high costs. The design was also unusual for its time and a decision had been made to allow higher than normal costs for all aspects of the building to achieve open spaces and for both function and symbolic reasons. Hence the proportion of structural to total cost probably remained similar to ordinary buildings. The effect of spans longer than normal can be further illustrated. The “usual” floor span 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 relatively 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. To increased 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 three times), the additional structural cost would be on the order of another 20 to 30 percent. The reference in the above cases is for floor systems. For roofs using efficient orthotropic (flat) systems, 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-frames are often used for steel spans over 150 ft the fabrication costs begin to raise considerably. At any rate, it should be recognized that very long-span subsystems are special cases and can in themselves 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 construction skill, will determine the potential for achieving cost efficiency. 4. Volume-Based Estimates When more accuracy is desired, estimates of costs can be based on the volume 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, with a moderate learning effort, to achieve some capability for making such estimates. Volume-based estimates are given by assigning in-place value to the pounds or tons of steel, or the cubic yards 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 forming, falsework, reinforcing steel, labor, and overhead. Steel includes fabrication and erection of components. Costs of structural steel as measured by weight range from ﹩0.50 to ﹩0.70 per pound 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 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 would typically be about 20 to 30 pounds of steel/psf, which one should wish not to exceed. A design calling for under 20 psf would require a great deal of ingenuity and the careful integration of structural and architectural components and would be a real accomplishment. 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 range 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. Form work is generally 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 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 labor costs account for high forming costs, this results in pressure to use the simplest and most repetitive of systems to keep costs down. It become rewarding to consider the possibility of mass-produced precast and prestressed components, which may bring a saving in costs and\or construction completion time. The latter results in savings due to lower construction financing costs for the contractor plus quicker earnings for the owner. 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 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. 5.Summary The estimate and economical design of structure building are important and essential work, which should be valued by all architects and engineers and others. Better you do it, more profit you will receive from it! 建筑结构的成本 1． 前言 众所周知，建筑物的结构 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 是一个相当复杂的过程，其中既包含处理很多物质因素，又考虑诸多非物质方面的因素。如果建筑物的结构形式对空间组织和美化环境的设计起这句举足轻重的影响，那么它就是一个相当重要的物理因素，就应当采用分阶段的设计 方法 快递客服问题件处理详细方法山木方法pdf计算方法pdf华与华方法下载八字理论方法下载 。 对建筑物的经济考虑是一个主要的非物质因素，在最终的设计中应予以重视。对一个具有创造性的设计而言，经济考虑从某方面来说往往是一种制约，但这也并非是绝对的。如果事先清楚结构设计及 施工 文明施工目标施工进度表下载283施工进度表下载施工现场晴雨表下载施工日志模板免费下载 组织 方案 气瓶 现场处置方案 .pdf气瓶 现场处置方案 .doc见习基地管理方案.doc关于群访事件的化解方案建筑工地扬尘治理专项方案下载 与实现他们的造价之间的关系，那么创造性是同样可以实现的。调查表明，大多具有创造性的设计是在有竞争性的投标中获得成功的，而不是因为业主非常富有。尽管后者被大肆炒作，却很少使人信服。因此也可以说，真正具有创造性的设计因该具有很强的经济性。特别是今天，人们应该逐渐认识到，高雅和经济其实是一个可以统一的概念。 因此，本文列举一些造价分析参数的简单解释，以及设计人员在他们的结构设计中考虑经济因素是经常采用的一些设计中考虑经济因素是经常采用的一些设计手法。 结构造价本身是通过其在建筑物总造价中所占的百分比来衡量的。或者说，由于 工程 路基工程安全技术交底工程项目施工成本控制工程量增项单年度零星工程技术标正投影法基本原理 只是一个项目总造价的一部分，因此还要考虑附加费用如地价（10%~20%）、筹资利息（100%~200%）、税金及维修费（20%左右）。不过上面这些因素都不在本文的讨论范围之内，文章将重点介绍工程造价。 平均来说，单纯的结构造价大约占建筑物总造价25%。按照惯例，建筑无的结构造价和所谓的建筑造价是分开的。一般说来，所谓的建筑造价，往往是指那些与建筑的结构强度和物理完整性无关的因素。 “基本服务设施费”组成了第三类工程费用，主要是指机械供给、电器设备以及其他一些服务体系等费用。一般说来，这部分费用大概占建筑物总费用的15%~30%，这主要取决于建筑无的类型。机械和电气费用，主要是指空调系统费用以及其他诸如管道系统、通讯、照明及动力设备等其他服务设施。 在这一造价分类中非常显著的一点是，一个典型的建筑物设计方案的总体费用，应该有45%~60%分配给建筑因素。但现在这种状况正在迅速改变，因为高利率以及资金的缺乏，现在大多业主更倾向于节约型设计。因此，设计者应该考虑两条途径，他们可以直接影响建筑无的工程造价。 第一个节约开支的途径可以这样来考虑，即凡是那些建筑问题和结构问题能够同时解决的地方往往有着很强的经济潜力。由于目前大多设计都不愿将建筑物费用一大部分用于纯粹建筑设计，这种方法就显得尤为重要，也会节省一部分非结构预算，这一经费可用于一些本会被削减掉的建筑需求。第二种节约开支的途径，则是设计人员在设计过程中综合考虑服务设施和结构体系，尽力提出一个能够解决房屋设计和施工难题的总建筑方案。 承包商通常回用不同的方式做出工程项目的最终报价。他们往往将其分为场地材料费、每一个施工过程中的劳动力资源费、工程所需购买、租借的装备费、经营管理费以及利润。建筑师以及工程师很少考虑的像上面所述的那么精确，但是头脑中应该有一个清楚的概念，那就是一项结构工程的实际造价最终使用什么方法定价以及承包商又是怎样标价的。 显然，上面讲到的百分比平均数有些粗略，但是它足以说明总体造价的组成情况了。下面的几部分将讨论这些平均数的范围，并进一步阐述在对建筑无的造价进行粗略、近似估计时用到的平方英尺以及单位体积造价。 2． 百分比估价 建筑物的类型将决定结构费用以及其他费用所占的白分比范围。正如所希望的，装饰性或者标志性较强的建筑物的结构造价在总体造价中所占的比重相对较低。一般而言，结构造价所占的百分比可低至工程总造价的10%~15%，这是因为更多的钱被用到那些非结构费用上了。这又一次说明“装饰”部分是与基本的结构要求无关的。然而对于一些诸如教堂类的综合性标志建筑物，对其结构体系的造价相对较高，其百分比可达到15%~20%或者更高。 与之相对的是一些诸如仓库或者车库之类简易的和非象征性的工业建筑物，对于这种建筑，由于内部隔墙、天花板、管道设备系统以及装修部分要求较低，其结构造价在工程总体造价中所占的比例往往能达到60%~70%，有时甚至可达80%。 对于一些中等高度（5~10层）得多层办公楼或住宅楼，其结构造价在总体造价中所占的比例，大约维持在25%这一中间值；而对于一些低矮且跨据短的商业用房和住宅，大约3~4层高且跨度为20~30英尺以及简单的竖向要求，其结构造价将占总造价15%~20%。 而一些特殊用途的建筑，如实验室和医院，则另当别论。他们需要较大的跨度以及不一般要求高的机械装备。这就导致总体造价得以大部分将被用于服务费用（大约30%~