Abstract:In recent years, as the protection problems of cable-stayed bridges are constantly being solved and improved, the related technology is also applied to the corrosion prevention of extracorporeal prestressing bundles, thus the problem of corrosion prevention of steel cables, which has been a key factor restricting the development of extracorporeal prestressing structures for several decades, has been solved to a large extent, and this undoubtedly greatly promotes the development of extracorporeal prestressing bridges, which have been stagnant due to the problem of corrosion. Prestressed concrete buildings constructed with in vivo reinforcement are severely damaged due to underestimation of the loss of prestressing force due to friction and the effects of concrete creep and temperature, resulting in the need for most of them to be reinforced, and the increase in load ratings requires the reinforcement of the original building. The reinforcement method usually has to be carried out outside the original structure, i.e., the prestressing Cambodia must be arranged outside the concrete cross-section, so that the extracorporeal cable reinforcement has become a major and the most active bridge reinforcement method. The advantages of extracorporeal prestressing system have been recognized by more and more people. Especially in developed countries, extracorporeal prestressing technology is widely used.

Abstract:The development overview of unbonded prestressed concrete structures is reviewed, and the current status of the application of unbonded prestressed concrete in bridge engineering is emphasized. On the basis of comparing the advantages and disadvantages of the two types of bondless and bonded prestressed concrete structures, it is pointed out that bondless prestressed concrete has a broad application prospect in bridge engineering. It analyzes the current situation of scientific research and design and construction of unbonded prestressed concrete technology in China, and points out that in order to promote the application of this new technology in bridge engineering, the design theory and method of unbonded prestressed concrete bridge should be systematically studied.

Abstract:With the rapid development of China's national economy, a large number of high-rise and ultra-high-rise buildings have been built one after another. And prestressing technology with its own characteristics, more and more is used in some high-rise buildings. This paper introduces the application of non-bonded prestressing technology in high-rise buildings by combining with the project of "Longsheng Building", especially the construction characteristics of prestressed wide flat beams, the coordination between prestressing construction and climbing scaffolding, and the technical and economic analysis after using prestressing.

Abstract:This paper describes the overall optimization and performance improvement of the LSD200 hydraulic synchronous lifting system. As well as hydraulic synchronous lifting technology in the lifting of large components of the engineering applications.

Abstract:Beipanjiang Bridge has been successfully implemented on January 20, 2001 to turn the body. Combined with the construction practice, this paper briefly introduces the technical measures and construction procedures adopted for the horizontal transfer of Beipanjiang Bridge (and the transfer of Xinzhai Bridge).

Abstract:The article points out that soil nail is soil anchor, soil nail wall is spray anchor support in soil layer. Ground excavation project exists stress redistribution, seepage field redistribution process, in general, with the excavation closely followed by the support, so the limit equilibrium design method has a large error, the paper introduces the guiding principles of the CSC method, soil nail wall force analysis, and concludes that the reinforcing steel mesh, spray concrete and soil anchors (soil nails) is the supporting structure of the matching. The paper further shows that the nonlinear large deformation theory of soft rock or soft soil ground excavation engineering is an effective tool for solving process problems.

Abstract:This paper reviews the development of cable-stayed bridge and stay cable, discusses the construction technology, welding technology, welding quality and welding equipment of the protective sleeve of stay cable, such as the full circle HDPE protective sleeve and half HDPE protective sleeve, and puts forward some suggestions on the connection of HDPE protective sleeve with tower and beam.

Abstract:The construction technology of movable Bailey truss girder of continuous girder bridge can bring its unique charm into play under good design and construction conditions. This method can make the internal force in construction stage consistent with that in operation stage, and the economic benefit is remarkable.

Abstract:In this paper, the temperature internal force calculated by the temperature field of each part of the bridge structure stipulated by the current bridge code in China is compared with the temperature internal force calculated by the temperature field of each part of the bridge structure stipulated by the British code "BS5400"(1982), and the influence of the temperature load on the internal force of the box girder is analyzed.