【正文】 materials, followed by the subsequent development of design theory and construction technology. Whenever there is a fine new building materials, the Civil Engineering will have leaptype development. People at an early stage can only depend on the soil, wood and other natural materials to create engaging activities, the subsequent emergence of such artificial brick and tile building materials, so that the first human to break the shackles of natural building materials. Chinese in the eleventh century BC and the early Western Zhou Dynasty to create the tile. The first brick in the fifth century BC to the third century BC, when the tomb of the Warring States Period. Brick and tile soil better than mechanical properties, can local materials, and easy to manufacture. The appearance of brick and tile people begin extensive and substantial in construction of housing and urban flood control projects. This civil engineering technology has been rapid development. Up to 18 ~ 19 century, at up to two thousand years, brick and tile has been a civil engineering building materials essential for the human civilization has made a great contribution, and even at present is also widely used. Steel substantial civil engineering applications are the second leap. 70s start the seventeenth century the use of pig iron, the beginning of the nieenth century the use of wrought iron construction of bridges and housing, steel this is a prelude to appear. From the beginning the middle of the nieenth century, metallurgical industry, smelting and rolling out of high tensile and pressive strength, ductility, and the quality of uniform building steel, and then produce highstrength steel wire, steel cable. Therefore necessary to adapt to the development of the steel structure has been booming. In addition to the application of the original beam, arch structures, the new truss, frames, grid structure, gradually extended the suspension structure, a structural form flowers Zhengyan situation. Building longspan structures from brick, stone structure, wood structure a few meters, the development of tens of meters to 100 meters of steel structures, a few hundred meters until 1000 meters above modern. So at Dajiang, both shelves starting Bridge, starting at the ground on the construction of skyscrapers and highrise tower, and even laying on the ground under the railway, to create an unprecedented miracle. 9 In order to meet the needs of the development of steel structure engineering, at the basis of Newton39。 some as a means of energy transmission and so on. This requires the integrated use of a variety of civil engineering material conditions in order to meet diverse needs. Civil Engineering has developed a lot of branches, such as housing projects, railway projects, road projects, airport projects, bridge projects, the tunnel and underground engineering, special engineering structures, water supply and drainage works, urban heating for the gas works, port works, water conservancy engineering sciences. Some of these branches, such as water conservancy project, because of their own projects targeted at the growing and specialized scientific and technological development have been divided out from the civil engineering disciplines as an independent system, but they are still largely in mon with civil engineering. Civil Sociality are acpanied by the development of human society developed. It reflects the construction of engineering facilities in every historical period of socioeconomic, cultural, scientific, technical development of the face, thus civil society has bee one of the historical development of the witness. Ancient times, people will start to build simple houses, roads, bridges to meet the needs of easy living and production needs. Later, the people in order to adapt to the war, production and dissemination of religious life and the needs of the construction of the city, canals, palaces, temples and other buildings. Many wellknown works shown in this historical period of human creativity. For example, China39。理論的內(nèi)容在實際生活中體現(xiàn)，將這兩個材料聯(lián)合使用比那些高彈性材料建造的結(jié)構(gòu)的 結(jié)構(gòu)設(shè)計復(fù)雜得多也更具挑戰(zhàn)性。因此，一個構(gòu)件在變形時，機械的連鎖提供自然截面的附著力，所以是非常接近這個假設(shè)的。設(shè)計是對一般的結(jié)構(gòu)和特定結(jié)構(gòu)等所有層面的一個具體的確定，使結(jié)構(gòu)可以被安全地建造，并安全地承受的各種因素的影響，在它的整個使用壽命中能夠很好的發(fā)揮作用。在這個過程中要做的最重要的事是：（ 1）充分的研究這個結(jié)構(gòu)，即能夠得到這個結(jié)構(gòu)所能承受的極限的結(jié)構(gòu)荷載的大小和強度（ 2）還有就是變形，了解結(jié)構(gòu)在承受荷載時變形的程度，出現(xiàn)裂縫的程度