外文翻译--结构工程在新时代遇到的机遇与挑战

1 Structural engineering in the newmillennium: opportunities andchallenges Abstract Purpose – Structural engineering as a part of civil engineering has over 5,000 years of distinguishedhistory, as documented in this paper. An attempt is made in this paper to define structural engineeringas it exists at present, then some historical structures are identified. Design/methodology/approach – The advances of structural engineering are discussed inchronological order, encompassing the development of the concept, analysis, the use of innovativeconstruction materials, and construction. The developments which necessitated the change of design philosophies are presented, and the current status of structural engineering is discussed in terms ofseveral specific topics. Opportunities and challenges in the new millennium in structural engineeringare then presented in terms of education, service to society, and research. Findings – In the past, structural engineering always met the challenges it faced. It helped toimprove our quality of life, and its role in society is not expected to change in the near future. Originality/value – The paper has provided an over-view of this important profession – fromancient history to the present day. Based on research over several decades it offers a prediction of thedirection in which this profession and the academic research that underpins it is likely to take in thefuture. Keywords- Structural engineering, Civil engineering, History Paper type- Literature review Introduction The task of defining structural engineering is very complicated. At present it is a majorpart of civil engineering in most countries, but it could be part of any engineeringdiscipline where structures need to be built. Before discussing the engineering aspectsof structures, the most interesting question often asked by the general public is “Whatis a structure?” In a philosophical way a structure can be defined as what we seearound us in the plant world, insect world and the animal (including human) world The leaf of a plant could be very interesting, even breathtaking, but they are 2 fragilestructures. A Saguaro Cactus is an extremely efficient structure and can live more than200 years under extreme conditions. Structures built by insects are also fascinating,and they build them to meet their needs. Who could ignore a spider’s web, a moundbuilt by termites, dams built by beavers, nests built by birds, or hives built by bees? Structures built by animals. including humans, do not need any further discussion.However, with our advanced knowledge at present we can define structuralengineering as a discipline that helps us to transfer a load applied in space to theground in the most efficient way. With this definition, the most efficient structure willbe a simple pole to bring a point load applied in the space. Structural engineering Structural engineering consists of several interconnected areas including developingunderlying physical principles, then presenting them in the form of governing equations, developing analysis techniques to solve the governing equations,integrating theories and material properties (mechanics of materials) to givespecialized structural forms, and then developing innovative construction techniques to give the concept a realistic, practical and aesthetic form. In all of these areas,structural engineers contribute significantly by combining mathematical, scientific, artistic, and entrepreneur skills.The significant contributions of structural engineering can be established bystudying some old historic structures. The building of pyramids could be one of thosemonumental events. It should be noted that structures made with stone and mud or with other available materials were built before pyramids, say around 3000 BC, but forthis discussion they are not considered to be engineered structures. The first pyramidwas the Step Pyramid at Saqqara, built for King Zoser in 2750 BC. This represents thefirst application of large-scale technology. Imhotep, the architect of the Step Pyramid isoften credited with its design. He was not a pharaoh or structural engineer, but was the Director of Works of Upper and Lower Egypt. The superstructure of the pyramid was made of small limestone blocks and desert clay. The Great Pyramid of Giza was built by the Egyptian pharaoh Khufu of the Fourth Dynasty around the year 2560 BC toserve as his tomb. The way we define structural engineering today was most likely initiated at thetime of Lord Buddha, about 500 BC Greeks played very important roles during thistime – the 3 Parthenon was built in 438 BC. Experience, intuition, and empirical rulesmight have played very crucial roles at this early stage of development. Stone andmasonry were the primary materials used for the construction. Then Aristotle(384-322 BC) and Archimedes (287-212 BC) came into the picture. They are credited withinitiating the development of the principles of statics. Then Romans started building arches, domes and vaults using stone, masonry, wood, and some metal. They did notuse any analytical principles, but used some basic forms to build their structures. This type of activity continued for about 1,000 years, say up to about 500 AD Design philosophies Advances in numerical analysis techniques also identified the weaknesses in them.Most of these techniques work very well verifying failures but are generally unable toprevent failures. One of the main reasons for this is our inability to predict futureloadings and the corresponding material behavior. This is also reflected in thedevelopment in the design guidelines In a historical perspective, hazards in structural engineering were observed at least4,000 years ago. The earliest known building code was used in Mesopotamia.Hammurabi, the king of Babylonia, who died about 1750 BC, issued code provisions.They were carved in stones and they can be seen in the Louvre in Paris. Theyaddressed many different issues including economic provisions (prices, tariffs, trade,and commerce), family law (marriage and divorce), criminal law (assault, theft), andcivil law (slavery, debt). Current status of structural engineering We will first try to address issues related to structural/civil engineering education.Then, we would like to identify some of the areas where structural engineers havemade significant contributions in the recent past. In his own career, the first authorused slide rule, log table, T-square, bevel set squares, etc. For this discussion, evenobservations he made early in his career are considered to be old in a relative sense. Wewill emphasize some recent developments. The list is not exhaustive and items arepresented not in the order of importance Opportunities and challenges in the new millennium It is clear from the previous discussion that structural engineering has a long andillustrious history. Where do we go from here? Recent devastating failures duringearthquakes, tsunami, hurricane or tornado, impact and explosive incidences, fire, etc.,demonstrated to the world community our inability to design and construct