Abstract:After more than a century of development and application of structural concrete materials, the internal and external causes of its failure mechanism and the corresponding strengthening measures, such as the use of steel fiber concrete, reinforced concrete and prestressed concrete for in-depth research, so that this material can not only replace steel structure, save materials, but also used in areas that steel can not be involved, such as nuclear power plant containment, offshore oil platform, oil storage Cans, etc.; The application prospect of concrete in ocean engineering is discussed by analyzing the failure nature, restraint effect and strengthening measures of concrete.

Abstract:Aiming at the structural safety of nuclear power plant containment anchorage system, the finite element analysis software ANSYS is used to analyze and compare the force of OVM15R-37C anchor plate and the optimized OVM15R-37CP anchor plate. The results show that the optimized anchor plate not only has better performance, but also is more economical than the former. Based on the experimental results of load transfer of OVM15R-37CP anchor plate and the stress distribution of concrete in anchoring area, the safety of structure and the rationality of finite element simulation are verified.

Abstract:Carbon fiber cloth has many advantages, such as corrosion resistance, simple and rapid construction, and has been widely used in civil engineering. ANSYS software is used to simulate the bending of unreinforced beams and 5 CFRP beams, and the corresponding load deflection curves are given. Compared with the experimental results, the established finite element model can simulate the mechanical properties of CFRP beams well, and the nonlinear finite element simulation results are in good agreement with the experimental results.

Abstract:How to determine the bearing capacity of the prestressed reinforcement anchorage area is a problem that has long been of great concern to the domestic and foreign industry. Foreign technical standards require the test method of applying pressure to the test pieces to verify. In China, the practice is that the embedded parts and anti-cracking steel bars within the concrete structure are designed by the structural designer, and the anchors outside the structure are designed by the anchor manufacturers. However, the whole set of clip-type anchors contains the anchors outside the structure and the supporting parts in the structure, resulting in an unclear situation. Since October 2010, China's industry standard JGJ85-2010 "Technical Regulations for the Application of anchors, fixtures and connectors for prestressed tendons" first proposed that when entering the acceptance of anchors, if the anchor plate is cast, the anchor manufacturer should conduct the force transfer performance test in the anchoring area, and the structural designer believes that the force transfer performance of the anchoring area can not meet the requirements The test results show that the standard is basically consistent with the acceptance standard of the American Post-tensioning Prestressing Institute (PTI). In March 2011, the Ministry of Communications of China issued the industry standard "Anchors, fixtures and Connectors for Prestressed steel strand wires of Highway Bridges" (JT/T329-2010), requiring that the structural size of the anchor plate should be able to reliably transfer prestress from the anchor to the concrete member. The requirements of this standard are basically the same as those of FIP1993 on load transfer test. However, the Chinese industry is relatively new to the "load transfer test" and does not know much about how to conduct this test. In the future, domestic and foreign projects (such as high-speed rail, high-speed), especially foreign users may require anchor manufacturers to provide this test proof, and anchor manufacturers and structural designers need to face up to it. In this situation, this paper summarizes the test concepts, specimen production, test methods and requirements at home and abroad to provide a general information for the industry.

Abstract:For a long time, the allowable value of deflection in the middle span of girder bridge under constant load [ft] has been vacant in Chinese bridge regulations. Generally, live load deflection fp=[L/600] is used instead. After nearly 20 years of research, it is considered that this is an important reason for the common downwarping and floor cracking of P.C continuous beams in China. Through the analysis of the paper, it is proposed that the design should control the initial deflection before closing [f]≤L/4800 to ensure the safety of the bridge.

Abstract:Beijing Water Great Wall Landscape Bridge is a 75m flexible suspension bridge with 2 main cables, 4 sets of cable saddles, 46 sets of cable clips and boom, and 2 anti-wind cables. This paper mainly introduces the construction technology of main cable erection of landscape suspension bridge, and understands the construction characteristics, construction methods and construction points of landscape suspension bridge, hoping to provide reference for similar suspension bridge projects.

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