Civil engineering plays a key role in the development of civil engineering, first of all, civil building materials are the material basis of engineering, followed by the corresponding developed design theory and construction technology. Whenever new excellent building materials appear, civil engineering will advance by leaps and bounds.

In the early days, people could only rely on natural materials such as soil and wood to engage in construction activities. Later, artificial building materials such as bricks and tiles appeared, which made mankind break through the shackles of natural building materials for the first time. China made ceramic tiles in the early Western Zhou Dynasty in BC 1 1 century. The earliest bricks appeared in the tombs of the Warring States Period from the 5th century BC to the 3rd century BC. The mechanical properties of brick and tile are superior to that of soil, which can be obtained from local materials and easy to process.

With the appearance of bricks and tiles, people began to build houses and urban defense projects on a large scale. Therefore, civil engineering technology has developed rapidly. Until 18 ~ 19 century, brick and tile, as an important building material in civil engineering, has a history of more than 2,000 years, which has made great contributions to human civilization and is even widely used at present.

The wide application of steel is the second leap in civil engineering. Pig iron was used in the 1970s, and wrought iron was used to build bridges and houses in the early 9th century, which was the prelude to the appearance of steel structures.

Since the middle of19th century, the metallurgical industry has smelted and rolled construction steel with high tensile and compressive strength, good ductility and uniform quality, and then produced high-strength steel wires and cables. So the steel structure that meets the needs of development has flourished. In addition to the application of the original beam-arch structure, the emerging truss, frame, grid structure and suspended cable structure are gradually popularized, and the situation of various structural forms has emerged.

The span of buildings has developed from several meters and dozens of meters of brick structure, stone structure and wood structure to hundreds and hundreds of meters of steel structure, until the modern 1000 meters. So bridges were built on the great rivers and straits, skyscrapers and towering iron towers were built on the ground, and even railways were laid underground, creating an unprecedented miracle.

In order to meet the needs of steel structure engineering development, on the basis of Newtonian mechanics, material mechanics, structural mechanics and engineering structure design theory came into being. The theory of construction machinery, construction technology and construction organization design has also developed, and civil engineering has risen from experience to science, and has a new look in engineering practice and basic theory, thus promoting the more rapid development of civil engineering.

1In the 1920s, after Portland cement was made, concrete came out. Concrete aggregate can be obtained from local materials, and concrete components are easy to form, but the tensile strength of concrete is very small, so its use is limited. /kloc-After the middle of the 0/9th century, the output of steel increased sharply, followed by the emergence of reinforced concrete, a new type of composite building material. Steel bears tension and concrete bears pressure, giving full play to their respective advantages. Since the beginning of the 20th century, reinforced concrete has been widely used in various fields of civil engineering.

Since 1930s, prestressed concrete has appeared. The crack resistance, stiffness and bearing capacity of prestressed concrete structures are much higher than those of reinforced concrete structures, so they are more widely used. Civil engineering has entered a historical period in which reinforced concrete and prestressed concrete are dominant. The appearance of concrete has brought new economic and beautiful engineering structure forms to buildings and new construction technology and engineering structure design theory to civil engineering. This is another leap development of civil engineering.

The construction of an engineering facility generally goes through three stages: survey, design and construction, which requires the use of knowledge, construction technology, construction organization and other technologies in the fields of engineering geological survey, hydrogeologic survey, engineering survey, soil mechanics, engineering mechanics, engineering design, building materials, construction equipment, engineering machinery, construction economics, as well as electronic computers and mechanical tests. Therefore, civil engineering is a comprehensive subject, involving a wide range. With the progress of science and technology and the development of engineering practice, the discipline of civil engineering has also developed into a comprehensive system with wide connotation, numerous categories and complex structure.

Civil engineering develops with the development of human society. The engineering facilities it built reflect the development of social economy, culture and science and technology in various historical periods, so civil engineering has become one of the witnesses of social and historical development.

In ancient times, people began to build simple houses, roads, bridges and gullies to meet the needs of simple life and production. Later, people built cities, canals, palaces, temples and other buildings to meet the needs of war, production and life and religious communication.

Many famous engineering facilities show the creativity of human beings in this historical period. For example, the Great Wall in China, Dujiangyan, the Grand Canal, the wooden pagodas in Zhao Zhouqiao and Yingxian, the Egyptian pyramids, the Parthenon in Greece, the water supply project in Rome, the Colosseum in Rome, and many other famous churches and palaces.

After the industrial revolution, especially in the 20th century, on the one hand, society put forward new demands for civil engineering; On the other hand, all fields of society have created good conditions for the progress of civil engineering. Therefore, civil engineering in this period has developed by leaps and bounds. Large-scale modern industrial workshops, skyscrapers, nuclear power plants, roads and railways, long-span bridges, large-diameter transportation pipelines and long tunnels, grand canals, dams, large airports, large seaports and marine projects have emerged all over the world. Modern civil engineering constantly creates a brand-new material environment for human society and becomes an important part of modern civilization of human society.

Civil engineering is a practical subject. Early civil engineering was developed through engineering practice, summing up successful experiences, especially drawing lessons from failures. Starting from the17th century, modern mechanics, led by Galileo and Newton, combined with civil engineering practice, and gradually formed material mechanics, structural mechanics, fluid mechanics and rock mechanics as the basic theoretical disciplines of civil engineering. Only in this way can civil engineering gradually develop from experience to science.

In the development of civil engineering, engineering practical experience often precedes theory, and engineering accidents often show unforeseen new factors, which lead to the research and development of new theories. So far, the treatment of many engineering problems still depends on practical experience to a great extent.

There are two reasons why the development of civil engineering technology mainly depends on engineering practice rather than scientific experiments and theoretical research: First, some objective conditions are too complicated to carry out indoor experiments or field tests and theoretical analysis truthfully. For example, the stress and deformation of foundation, tunnel and underground engineering and their changes with time still need to be analyzed and judged with reference to engineering experience. Second, only by carrying out new engineering practice can new problems be revealed. For example, high-rise buildings, towering towers and long-span bridges have been built, and the problems of wind resistance and earthquake resistance of the project are prominent, so new theories and technologies in this field can be developed.

In the long-term civil engineering practice, people not only pay great attention to architectural art, but also have made outstanding achievements; In addition, for other engineering facilities, by using different building materials, such as stone, steel and reinforced concrete, many projects with beautiful art and good functions are in harmony with the natural environment. The Great Wall of Wan Li in ancient China, many TV towers in the modern world and Zhang Qiao are all examples. The number of words seems to be a little short. Sorry.