Abstract:In recent years, the domestic prestressed technical professionals pay more and more attention to the safety of prestressed anchorage area. The design and construction units of railway, highway bridge and special structure, as well as the main production enterprises of anchors, all put the bearing capacity of anchor plate and screw bar in the first place. The evaluation test methods and standards of the bearing capacity of anchoring areas have been formulated and released abroad decades ago, and China has also begun to explore, which is expected to be widely carried out in the near future. This paper collects seven standards from the United Kingdom, the International Prestressed Concrete Association, the European Standardization Committee, the European Technical Certification Organization, the National Highway and Transportation Association of the United States, the American Post-tensioning Society and other organizations, and introduces the load transfer test in the prestressed anchorage zone to the reader. The main contents are: the design of the specimen, the concrete strength requirement during the test, the loading procedure of the specimen, the collection and analysis of the specimen data, etc. I hope it can provide reference for the staff in the same industry to carry out this kind of work.

Abstract:This paper mainly introduces the watertightness test of OVM250 cable system products. By comparing the watertightness test requirements of the three major international cable standards PTI2007, fib2005 and CIP2002, combined with the actual working conditions of the steel cable stays, fib2005 and CIP200 are considered 2 The two codes require the watertightness test of cable products, and the various test parameters are the highest requirements in the two codes. The test water pressure parameters are 3m water pressure as required by fib2005, the test device is installed at a tilt of 30 degrees and the test period is 6 weeks according to CIP2002 specifications. Due to the lack of corresponding test equipment in qualified laboratories at home and abroad,OVM company designed and processed the test equipment and supporting test equipment according to the determined test parameters and CIP2002 standard test installation requirements. Under the double witness of the National Construction Engineering Quality Supervision and Inspection Center and the United States CTL laboratory, the watertightness test was carried out successfully, and the watertightness test was sufficient The sealing reliability of OVM250 cable anchor is verified.

Abstract:This paper introduces the design and application of a new walking type jacking device in the construction of multi-point synchronous continuous jacking of Bridges in Kunming. The device adopts 3D simulation and finite element design. It is a new generation bridge push construction device integrating push, translation and lateral correction. It has the characteristics of modularity, small volume, light weight, accurate and reliable execution of push cycle action and wide adaptability. The biggest advantage of the device is that there is a sliding surface in the device, and the sliding surface is not at the bottom of the bridge, between the slide box and the slide way, so that the force of the bridge and the pier structure is improved during the pushing process, and there is almost no damage to the bridge and the pier.

Abstract:The tension of the isolation rubber bearing is a very important control parameter for the design of the isolation layer of the isolation structure. In this paper, the parallel connection of Isolator1 unit and Gap unit in the etabs2013 analysis software is used to simulate the isolation rubber bearing, so as to reflect the vertical mechanical properties of the isolation rubber bearing more truly. In this study, the stiffness of Isolator1 element and Gap element are allocated according to the tensile and compressive stiffness of the support through a practical engineering model. The analysis data show that the tensile stress of Isolator1 element of the new model is significantly reduced, while other horizontal performance indexes remain unchanged. The results show that the method can be applied to the time-history analysis of isolated structures. It provides a valuable reference for practical engineering analysis.

Abstract:On the basis of the brief introduction of the research and application of intelligent prestressed tension system in China, this paper introduces the composition of typical intelligent prestressed tension system, which mainly includes the application of post-tensioned beam, pre-tensioned beam, ground anchor cable and steel strand, etc. Then it Outlines the effective prestress measurement method based on magnetic flux technology, and finally describes the intelligent tension system Engineering application of unified and effective prestress measurement methods. Using the prestressed intelligent tensioning system in this paper, the tensioning construction, data recording and construction management of the prestressed beam can be carried out scientifically and normatively according to the preset program, the influence of manual intervention factors can be reduced, and the quality of prestressed tensioning construction can be effectively guaranteed.

Abstract:The installation of cable-stayed cable is the key link of cable-stayed bridge construction. Taking the construction of cable-stayed cable of Tongling Yangtze River Bridge of Hefu Railway as an example, the new construction technology of cable-stayed cable of Tongling Yangtze River Bridge is introduced. By using this technology, the problems of difficult construction, easy to fall and serious damage to the cable body in the conventional construction methods are effectively avoided, and the safe, efficient and high quality installation of the steel strand cable is ensured.

Abstract:Because the construction technology of prestressed concrete is a professional, strict operation requirements, high technical content of the work, so the quality control of prestressed concrete plays a crucial role in the construction of the structure, and then affects the quality of the whole project. In view of this, this paper analyzes and summarizes the key points of prestressed concrete construction quality control from the three stages of construction, construction and completion, in order to play a reference and guidance role in engineering practice.

Abstract:Self-anchored suspension bridge is a bridge with cable or chain as the main load-bearing component, which is composed of suspension cable, tower, anchor, boom, bridge floor system and so on. This paper introduces the construction technology and technology of the suspension system of single tower and double span self-anchored suspension bridge based on the case of Guzhen No. 2 Bridge (Xuyaodu Transformation Bridge), which provides reference and experience for the construction of similar Bridges in the future.