【正文】 ......................................... 6 Reinforced Concrete ........................................... 6 Earthwork ..................................................... 7 Safety of Structures .......................................... 9 一級(jí)標(biāo)題，黑體，三號(hào)，居中 唐 山 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 1 1 中文翻譯 素混凝土是由水泥、水、細(xì)骨料、粗骨料（碎石或；卵石）、空氣，通常還有其他外加劑等經(jīng)過(guò)凝固硬化而成。這一要求是可以達(dá)到的。 水泥的水化作用發(fā)生在有水分存在，而且氣溫在 50176。由于經(jīng)常需要進(jìn)行多次試算，才能求出所需的截面，因此設(shè)計(jì)時(shí)第一次采用的數(shù)值將導(dǎo)致一系列的試算與調(diào)整工作。因此，一個(gè)工程師為了使自己在土方挖運(yùn)設(shè)備方面的知識(shí)跟得上時(shí)代的發(fā)展，他應(yīng)當(dāng)花費(fèi)一些時(shí)間去研究現(xiàn)代的機(jī)械。這并不是經(jīng)?？梢宰龅降?，但是如果能夠做到則是很理想的，因?yàn)檫@樣做既快捷又省錢。正鏟挖土機(jī)能挖取豎直陡峭的工作面，這種方式對(duì)推土機(jī)司機(jī)來(lái)說(shuō)是危險(xiǎn)的，而對(duì)拉鏟挖土機(jī)則是不可能的。滿載時(shí)可達(dá) 10 m179。的鉸接式翻斗車。其例子包括結(jié)構(gòu)的局部屈曲和整體不穩(wěn)定性；某此界面失效，隨后結(jié)構(gòu)轉(zhuǎn)變?yōu)闄C(jī)構(gòu)；疲勞破壞；引起結(jié)構(gòu)幾何形狀顯著變化 的彈性變形或塑性變形或徐變；結(jié)構(gòu)對(duì)交變荷載、火災(zāi)和爆炸的敏感性。計(jì)算荷載等于分別乘以荷載系數(shù)的活載與恒載之和。 所有這些因素均與經(jīng)濟(jì)和社會(huì)條件有關(guān)，例如： （ 1） 建筑物的初始建設(shè)費(fèi)； （ 2） 建筑物使用期限內(nèi)的折舊費(fèi)； （ 3） 由于建筑物破壞而造成的物質(zhì)和材料損失費(fèi)； （ 4） 在社會(huì)上造成的不良影響； （ 5） 精神和心理上的考慮。 F. It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surface cracking takes place. This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydration. It is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain, steel stress, and so on. Consequently, trial and adjustment is necessary in the choice of concrete sections, with assumptions based on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental reinforced concrete is often a siteconstructed posite, in contrast to the standard millfabricated beam and column sections in steel structures. A trial section has to be chosen for each critical location in a structural system. The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load. Since more than one trial is often necessary to arrive at the required section, the first design input step generates into a series of trialandadjustment analyses. The trialand –adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design. Hence every design is an analysis once a trial section is chosen. The availability of handbooks, charts, and personal puters and programs supports this approach as a more efficient, pact, and speedy instructional method pared with the traditional approach of treating the analysis of reinforced concrete separately from pure design. Earthwork Because earthmoving methods and costs change more quickly than those in any other branch of civil engineering, this is a field where there are real opportunities for the enthusiast. In 1935 most of the methods now in use for carrying and excavating earth with rubbertyred equipment did not exist. Most earth was moved by narrow rail track, now relatively rare, and the main methods of excavation, with face shovel, backacter, or dragline or grab, though they are still widely used are only a few of the many current methods. To keep his knowledge of earthmoving equipment up to date an engineer must therefore spend tine studying modern machines. Generally the only reliable uptodate 唐 山 學(xué) 院 畢 業(yè) 設(shè) 計(jì) 8 information on excavators, loaders and transport is obtainable from the makers. Earthworks or earthmoving means cutting into ground where its surface is too high ( cuts ), and dumping the earth in other places where the surface is too low ( fills). Toreduce earthwork costs, the volume of the fills should be equal to the volume of the cuts and wherever possible the cuts should be placednear to fills of equal volume so as to reduce transport and double handlingof the fill. This work of earthwork design falls on the engineer who lays o