【正文】 Must have sufficient fracture toughness of the steel structure, in particular by the alternating load and impact load of the building structure to have this feature. The fracture toughness of the steel structure is very sensitive to temperature conditions, and decreases as the temperature decreases. Design of steel structures in cold weather areas, we must first consider the toughness. Relatively speaking, lowcarbon the niobium steel is high carbon steel ingredients steel is more improved toughness. 、 Overall Overall from the foregoing, either from the stiffness, strength and ductility, steel structure is better than the reinforced concrete and steel structures can be relatively easy to construct exotic architectural forms, usually steel system can provide the best designflexibility and maximum space utilization. Another advantage of the steel structure is: it is an ideal cantilever construction system. Appropriate application fasting steel bracket and ponent web openings for pipes and other supply line channel, not only reduces the height of the floor, and increased aesthetic appeal. Steel frame like the steel structure, which is used to extend the existing concrete building structure or increase the floor. During the construction and assembly of steel structures construction workers is much less than the required number of concrete building structures。s national economy, the price advantage of the concrete is manifested. 、 The useful life of the steel structure Concrete structure known as never damaged steel structure general life of only 50 years, if the steel structure used in residential buildings, people expect to spend life savings to buy a house only live 50 years, will make a lot of peopleloss of desire to buy. However, with the development of the insurance industry, residential life issues should be relatively easy to solve. Steel construction installation points The whole steel structure construction process is more plex, and the requirements of the building, is very different in detail. At three points listed here will be briefly described. 、 Selection and connection The steel is usually divided into plates, profiles, metal products and pipe four major categories. Civil engineering construction steel monly used ordinary lowalloy steel, quality carbon structural steel and carbon steel, low carbon steel plastic, but the intensity is relatively high hardness. The steel structure, the crosssection of the column is generally boxsection or wideflange workersshaped, in addition to Xshaped cross section and so on。通常情況下，二十四個(gè)小時(shí)后可以用清水或者毛刷清理表面的磷化殘留物。 涂防銹漆、刮膩?zhàn)? 在涂漆前要保證金屬表面的干燥，如果有水份則要立即擦干。一般鋼結(jié)構(gòu)的安裝采用的是塔式起重機(jī)，臂桿長(zhǎng)度要有夠的覆蓋面，并且起重能力要相應(yīng)足夠，從而滿足各種不同部位構(gòu)件的起吊要求。在鋼結(jié)構(gòu)中，柱子截面一般多為箱形截面或者寬翼緣“工”字形，另外還有“十”字形截面等等；梁多數(shù)是焊接或者軋制的“ H”型鋼梁，如果要求特殊也可以符合截面，在安裝前要對(duì)主要的焊 接接頭做焊接工藝的試驗(yàn)，定出焊接的格料和各項(xiàng)參數(shù)。 價(jià)格問(wèn)題 由于鋼結(jié)構(gòu)的生產(chǎn)未形成體系，因此鋼結(jié)構(gòu)的價(jià)格比較高。因此要提高這些構(gòu)件的穩(wěn)定性，就要增加型鋼的尺寸或者采取填充混凝土以及外包混凝土的措施，以提高截面的剛度。相對(duì)來(lái)說(shuō)，低碳鈮鋼比高碳鋼成分鋼更能改善韌性。不過(guò)雖然鋼結(jié)構(gòu)的應(yīng)變延性比較高，但是因?yàn)槭軓潣?gòu)件的受力不穩(wěn)定，所以構(gòu)件的曲率延性經(jīng)常不足。結(jié)構(gòu)體系的實(shí)際剛度又由其構(gòu)件和連接件的分布來(lái)決定。 附件 1：外文資料翻譯譯文 鋼結(jié)構(gòu)在土木工程中的研究應(yīng)用 土木工程結(jié)構(gòu)常用到兩種材料，即鋼筋混凝土以及結(jié)構(gòu)鋼，對(duì)于土木工程來(lái)說(shuō)，不僅要從結(jié)構(gòu)特性的角度考慮，還要考慮施工的成本有效性以及施工有效性。可以利用有關(guān)的國(guó)家標(biāo)準(zhǔn)來(lái)確定結(jié)構(gòu)鋼的構(gòu)件性能，這些標(biāo)準(zhǔn)中列出了鋼結(jié)構(gòu)可使用的材料，比如建筑結(jié)構(gòu)鋼要滿足 CSA 標(biāo)準(zhǔn) ASTM standardA992/A992M 或者 CAN/CSA 。一般情況下延性是結(jié)構(gòu)設(shè)計(jì)中，特別是抗震設(shè)計(jì)中比較重要的特性參數(shù)，地震中幸存的建筑物直接依賴于主要結(jié)構(gòu)框架經(jīng)歷大的非彈性變形時(shí)的滯后耗能性。韌性通常表示鋼結(jié)構(gòu)在制造、安裝以及使用過(guò)程中可以承受比較大的工業(yè)變形，是鋼結(jié)構(gòu)一個(gè)很重要的特點(diǎn)。適當(dāng)?shù)膽?yīng)用空腹鋼鐵托架以及構(gòu)件腹板開(kāi)孔，可 以為管道以及其它供電線路提供通道，不僅降低了樓層的高度，而且增加了審美吸引力。 市場(chǎng)環(huán)境 設(shè)計(jì)力量較薄弱 在設(shè)計(jì)建筑結(jié)構(gòu)時(shí)要注意結(jié)構(gòu)的功能要求是不是屬于鋼結(jié)構(gòu)合理的應(yīng)用范圍。不過(guò)隨著保險(xiǎn)業(yè)的發(fā)展，住宅壽命問(wèn)題應(yīng)該 相對(duì)容易解決。在技術(shù)條件允許時(shí)比較適合采用多軸數(shù)控鉆孔。各個(gè)塔式起重機(jī)之間要有相應(yīng)的安全距離，以保證臂桿與塔身不相碰撞?？梢栽谀?zhàn)又屑尤脒m量的紅丹粉或者厚漆，從而增加其干硬性。涂刷后要及時(shí)檢查避