Abstract:In recent years, China's high-speed railways, expressways, ordinary road railways, intercity railways, underground railways and many infrastructure projects have increased a lot, and the use of prestressed concrete structures has continued to grow rapidly. The production and supply of prestressed tension anchoring system has increased greatly, of which the largest use is prestressed steel strand and clip anchorage,2009 and 2010, China produced 150 million holes a year clip anchorage, far more than European and American countries. However, there are still some problems that should be solved, such as: the ease of use of prestressed steel strand should be improved, the size of the anchor kit (anchor plate, spiral bar, etc.) should be returned to the scientific level, the overall view of the efficiency coefficient of the anchor, and to ensure the safety of the prestressed reinforcement anchorage area in the structure is the most important problem at present. The current situation in China has required the load transfer test to be included in the national product standards. In this period of great development of prestressed engineering, the Concrete and Prestressed Concrete Branch of China Civil Engineering Society has always paid close attention to the performance of prestressed tension anchorage system in engineering practice.

Abstract:In this paper, long-term monitoring tests are carried out on the dynamic resistance values of the traditional metal bellows hole anchoring system and the OVM.M15ZH electrical insulation anchoring system respectively, and the operability of the construction method of OVM.M15ZH electrical insulation anchoring system is verified. The test results show that the construction method of OVM.M15ZH electrical insulation anchoring system is as convenient and reliable as that of conventional anchoring system. The dynamic resistance value of the traditional metal bellows hole anchoring system remains basically unchanged, while the dynamic resistance value of OVM.M15ZH electrical insulation anchoring system increases with the passage of time. The test results provide some reference and basis for non-destructive monitoring of the corrosion of prestressed tendons by OVM.M15ZH electrical insulation anchoring system in the next step.

Abstract:How to improve the aseismic and safety of Bridges in earthquakes has always been a research focus. This paper introduces the principle and characteristics of the anti-fall beam device, and explains its application through its application in a project. As a secondary protection system for Bridges, increasing its application has important significance for improving the safety of domestic Bridges.

Abstract:This paper mainly introduces the replacement construction of the old derrick of Guiping Qianjiang Bridge and the design and application of the special structure of the derrick. This project is to replace the old header wire of φ5 with an OVM.250 clip anchorage and GJ steel strand whole bundle extruding combined derrick. This scheme is the first time in the design of the two different anchoring methods combined, and used in the old bridge cable replacement. According to the particularity of the structure, the design idea and the special construction method of the derrick are introduced.

Abstract:The use of carbon fiber sheet (CFRP) to strengthen reinforced concrete members is an advanced engineering strengthening technology, which has been widely used in civil engineering. In this paper, ANSYS software is used to simulate the bending of prestressed and non-prestressed beams reinforced by carbon fiber to analyze and study the mechanical mechanism and reinforcement effect of carbon fiber reinforced concrete beams, and the corresponding load deflection curve is given. The results show that the beams reinforced with prestressed carbon fiber are obviously superior to the damaged beams reinforced with ordinary carbon fiber cloth, which not only improves the bearing capacity of the structures at various stages, but also reduces the deflection of the beams during failure.

Abstract:The basic principle of TSP system and ground penetrating radar in tunnel advance geological prediction is introduced. The application of TSP system and ground penetrating radar in a tunnel of Xiashen-Shenzhen Railway is taken as an example to further verify the accuracy of the comprehensive detection technology in tunnel geological prediction.

Abstract:In view of the importance of future urban subway shield tunnel management and maintenance, this paper fully draws on the existing railway tunnel and highway tunnel management technology methods, in-depth analysis of the characteristics of subway shield tunnel, combined with tunnel detection engineering experience, the subway shield tunnel structure quality safety evaluation system analysis, in an attempt to establish the early operation of subway tunnel related technical standards Give some useful insights.

Abstract:This paper introduces the key points of quality control in the prestressed construction of 48+80+48m continuous beams on pier 8 ~ 11 of Tokyo Temple Bridge, from the embedding of pipes, the arrangement of prestressed reinforcement bars to the application of prestressed stress.

Abstract:Asphalt pavement is the common type of highway pavement in our country at present, it has the advantages of durable anti-skid, solid and smooth, and can provide safe and comfortable conditions for vehicle driving. However, due to the influence of environment, climate and other factors, local settlement, rutting, oil flooding, cracks and other diseases often occur. This paper briefly discusses the causes of the main diseases of asphalt concrete pavement, and puts forward the countermeasures against the diseases for reference.

Abstract:The anchoring force loss of prestressed anchor cable will cause its anchoring effect to weaken or even fail, which will bring great harm to engineering safety. In the process of program design, studying the influence factors such as anchor system, anchor cable structure, anchor cable spacing, anchor cable tonnage and rock and soil properties, and taking certain design measures can effectively restrain, reduce or even eliminate the influence of anchor force loss, which has important theoretical and engineering practice significance for the design, construction and safe operation of anchor engineering, and improve the economic and social benefits of the project.