1、中文 5370 字， 3300 单词 ， 17900 英文字符 出处： Galambos T V. Recent research and design developments in steel and composite steelconcrete structures in USAJ. Journal of Constructional Steel Research, 2000, 55(s 13):289-303. 外 文 译 文 学 院 建筑工程学院 专业班级 土木工程 学生姓名 学 号 Recent Research and Design Developments in Steel
2、and Composite Steel-concrete Structures in USA The paper will conclude with a look toward the future of structural steel research. 1. Research on steel bridges The American Association of State Transportation and Highway Officials (AASTHO) is the authority that promulgates design standards for bridg
3、es in the US. In 1994 it has issued a new design specification which is a Limit States Design standard that is based on the principles of reliability theory. A great deal of work went into the development of this code in the past decade, especially on calibration and on the probabilistic evaluation
4、of the previous specification. The code is now being implemented in the design office, together with the introduction of the Systeme Internationale units. Many questions remain open about the new method of design, and there are many new projects that deal with the reliability studies of the bridge a
5、s a system. One such current project is a study to develop probabilistic models, load factors, and rational load-combination rules for the combined effects of live-load and wind； live-load and earthquake； live-load, wind and ship collision； and ship collision, wind, and scour. There are also many fi
6、eld measurements of bridge behavior, using modern tools of inspection and monitoring such as acoustic emission techniques and other means of non-destructive evaluation. Such fieldwork necessitates parallel studies in the laboratory, and the evolution of ever more sophisticated high-technology data t
7、ransmission methods. America has an aging steel bridge population and many problems arise from fatigue and corrosion. Fatigue studies on full-scale components of the Williamsburg Bridge in New York have recently been completed at Lehigh University. A probabilistic AASTHO bridge evaluation regulation
8、 has been in effect since 1989, and it is employed to assess the future useful life of structures using rational methods that include field observation and measurement together with probabilistic analysis. Such an activity also fosters additional research because many issues are still unresolved. On
9、e such area is the study of the shakedown of shear connectors in composite bridges. This work has been recently completed at the University of Missouri. In addition to fatigue and corrosion, the major danger to bridges is the possibility of earthquake induced damage. This also has spawned many resea
10、rch projects on the repair and retrofit of steel superstructures and the supporting concrete piers. Many bridges in the country are being strengthened for earthquake resistance. One area that is receiving much research attention is the strengthening of concrete piers by jacketing them by sheets of h
11、igh-performance reinforced plastic. The previously described research deals mainly with the behavior of existing structures and the design of new bridges. However, there is also a vigorous activity on novel bridge systems. This research is centered on the application of high-performance steels for t
12、he design of innovative plate and box-girder bridges, such as corrugated webs, combinations of open and closed shapes, and longer spans for truss bridges. It should be mentioned here that, in addition to work on steel bridges, there is also very active research going on in the study of the behavior
13、of prestressed concrete girders made from very high strength concrete. The performance and design of smaller bridges using pultruded high-performance plastic composite members is also being studied extensively at present. New continuous bridge systems with steel concrete composite segments in both t
14、he positive moment and the negative moment regions are being considered. Several researchers have developed strong capabilities to model the three-dimensional non-linear behavior of individual plate girders, and many studies are being performed on the buckling and post-buckling characteristics of su
15、ch structures.Companion experimental studies are also made,especially on members built from high-performance steels. A full-scale bridge of such steel has been designed, and will soon be constructed and then tested under traffic loading. Research efforts are also underway on the study of the fatigue
16、 of large expansion joint elements and on the fatigue of highway sign structures. The final subject to be mentioned is the resurgence of studies of composite steel concrete horizontally curved steel girder bridges. A just completed project at the University of Minnesota monitored the stresses and the deflections in a skewed and
