421530m簡支轉(zhuǎn)連續(xù)箱梁的畢業(yè)論文-資料下載頁

　　

【正文】 社，[4]：人民交通出版社，[5]鄒松毅，：人民交通出版社，[6]：西南交通大學出版社，.[7]：人民交通出版社，2001. 英文文獻THE MAIN PROBLEMS OFDOMESTIC BRIDGE DESIGNINGNow, the country39。s structural design process, such tendencies: more intensity considered in the design and durability consider less attention intensity limit to the use of state without limit state, and throughout the life cycle of the most important when it is precisely the use of performance。 attention to the construction of the structure without attention to the maintenance of the structure. In fact, the current design of the bridge for more durability is a concern, as a concept, did not explicitly put forward the request of the use of life, nor the durability of specialized design. These tendencies to a certain extent, led to the current project accidents, the use of poor performance, the short life of the adverse consequences of structural engineering with the increasing emphasis on international durability, safety, contrary to the trend of applicability。 does not conform to the structure dynamic and prehensive economy requirements.Bridge safety, durability, the main reason for poor 1) Construction and management of low level More bridges at home and abroad destruction and the sudden collapse of the bridge has been engineering more concerned about security issues. The general view is that the current project is barbaric incident management and construction caused by corruption. For the short term, such as the destruction and collapse of a sudden, mostly because of construction quality did not meet specifications and design requirements, typical problems include inadequate and construction materials intensity of failure。 also exist, such as individual bridge jerry serious management issues, but also on bridge safety of the fatal damage.And a large number of bridges in the far did not achieve the expected life time, there has been affecting the normal use of disease and deterioration, especially in a number of bridges in use only a few years, or even just pleted soon on the serious problem of insufficient durability, which and the low quality of construction is an important relationship, the typical problems of inadequate protection of reinforced and the current widespread in the construction site of the serious problem of cracking ponent. These construction, although shortterm deficiencies of the bridge will not be the normal use of a clear impact, but the longterm durability of the structure will have a very negative hazards.2) Design theory and structure of the system is not perfect enoughWhile acknowledging the existence of the problem, but it also, it is undeniable that bridge design fields, in particular on the bridge construction and use of the issue of safety there is still much improvement. Structural design first and foremost task is the choice of reasonable economic programmer, followed by the structural analysis and design of ponents and connections, and access to regulate the safety factor specified or reliability of indicators to ensure the safety of the structure.Many designers often placent with norms on the structural strength of the safety of the need, and ignore the structural system, structure, structure, structure of materials, structure maintenance, as well as from the structural durability of the design and construction process to make use of that often appear in the manmade wrong areas to strengthen and guarantee the safety of the structure. Some structural integrity and ductility inadequate redundancy small, but some of Schema and the uncertainty of the line, causing partial excessive force。 some concrete strength grade too low to protect slice through small diameter steel micromanage , a thin crosssection ponents of these structures have weakened the durability, it would seriously affect the safety of the structure. Many bridges, although the design specifications meet the requirements of the strength of only 5 to 10 years because of the durability of the problems affecting structural safety. Structural Durability shortage has bee one of the most realistic security issues, from design to construction and materials, such as angle of measures to strengthen the durability of the structure.Of the environment and the use of different conditions, different design of the structural system will target different aspects of the layout and structure requirements. Norms can not cover in detail the design staff should solve the various problems in the updated norms faster can also adapt to new understanding, new technologies, new materials, rapid development of the structure of the new requirements. Therefore, reasonable and reliable addition to the structures is designed to meet the requirements of norms, and to design a structure to the correct understanding of nature, rich experience and accurate judgments.And the need to improve efforts in the direction 1) Should pay more attention to the durability of structural problemsBridge in the construction and use of the process, will be subject to environmental, and the erosion of harmful chemical substances, and to bear vehicles, wind, earthquake, fatigue, overloading, human factors, such as external role, and bridge materials used by the selfdegradation of performance will continue , resulting in the structure of the different degrees of damage and deterioration. In the field of longspan bridges, and from the country since the 1980s, the construction of a large number of cablestayed bridge, although so far there collapse or serious damage to the few examples, but has more bridges because of the durability of cable to the problem advance for cable, and this not only affects the use of increased economic losses.Needs to be pointed out is that many of these problems and did not conduct a reasonable durability of the design, which has also prompted renewed awareness of durability of the bridge. Diseases are a lot of examples of that