Abstract:In recent years, with the increasing traffic volume and traffic load, the force of the original boom cannot meet the requirements of the original design, and more and more maintenance of the boom of arch bridge, such as replacing the boom, will not only bring damage to the bridge itself, but also cause traffic congestion. Based on the practical application of Chengdu Ring-cheng high-speed Fuhe Bridge, this paper introduces the reinforcement system of the bridge and the existing problems in the design and construction, and puts forward suggestions on the existing problems to provide reference for the reinforcement design and construction of similar Bridges in the future.

Abstract:Hydraulic cable hoist mainly includes four parts: walking mechanism, steel truss, hydraulic lifting system and control system. The construction scheme of the main beam of the Zhuzhou Yangtze River Bridge in Wuhan is proposed to adopt hydraulic cable hoist. The paper proposes a walking mode combining hydraulic jack traction and multi-wheel walking, in which each walking wheel can be lifted or lifted independently or in combination, so that the hydraulic jack can still be steadily pulled during the walking process, and the walking wheel has been in contact with the main cable, the structure is simple, the walking speed is fast, the center of gravity of the structure is relatively low, and the overall safety is good. The walking mechanism of the cable hoisting crane is designed as a bi-directional symmetrical structure, which can realize the uphill and downhill walking in the same direction. The hydraulic pump station, which provides power for the hydraulic system, uses the diesel engine to drive the hydraulic pump station directly, which saves energy and reduces the volume of the pump station and generator combined system. The hydraulic lifting jack adopts a new structure that is easy to change the clip, and the retracting and retracting steel strand adopts a hydraulic motor power retracting and retracting device. Four new 5000k N cable hoisting cranes with hydraulic traction combined with rolling wheels were developed and applied to practical projects after the type test in the factory. From September 2013 to December 2013, 143 main beams of the whole bridge of Zhuozhou Yangtze River Bridge were successfully erected. The practice proves that the new cable-borne crane system developed is successful.

Abstract:By combining finite element analysis with cable tower model test, the stress analysis of the tower anchorage area of the low pylon cable-stayed bridge in Sanguan Hanjiang Highway, Wuhan City, was carried out to verify the static load and anti-slip performance of the single-sided bidirectional anti-slip device of the cable tower anchorage zone. The cable replacement process of a single steel strand in the operation stage of the real bridge was simulated by test, which provided technical support for design and construction. The test results show that the structure of the cable pylon anchorage area of the bridge is safe under stress, the anti-slip structure of the cable pylon anchorage area and the cable changing process of a single steel strand meet the design and specification requirements.

Abstract:This paper analyzes the types, advantages and disadvantages of the existing cable anchor system of the main suspension bridge in China, discusses some problems in the design and construction of the prestressed anchor system and puts forward some suggestions, and finally looks forward to the development of the prestressed anchor system.

Abstract:In recent years, rock and soil anchoring technology has been widely used in slope reinforcement and regulation projects. This paper mainly analyzes the problems encountered in the current stage of the development of geotechnical anchoring engineering technology, and discusses the mechanism, practical application range and development direction of this technology.

Abstract:Metal components in the process of processing will produce residual stress, residual stress is too large will cause serious harm to the components, such as reducing the strength of the components, reducing the fatigue limit of the workpiece, causing stress corrosion and brittle fracture, residual stress relaxation, deformation of the components, affecting the dimensional accuracy of the components. It is very important to reduce and eliminate the residual stress of the component. There are many techniques for residual stress relief, among which vibration aging is simple and effective. At the same time, there are many techniques for residual stress testing, among which the blind hole method is less destructive, has strong applicability, high data detection accuracy, and simple test process and operation. In this paper, the causes of the formation of residual stress, the techniques of eliminating it and measuring it are discussed in detail, and an example of vibration aging and measuring residual stress is given. The discussion of this paper has important reference value for the relevant engineering and technical personnel.

Abstract:Oil-based sealing wax has good anti-corrosion properties, can meet the requirements of cable anchor filling construction, and is not easy to lose and drip during cable operation, and is a new material more suitable for cable anchor anti-corrosion requirements. The material not only conforms to the requirements of bridge construction and environmental protection development, but also provides a new technology for strengthening the anti-corrosion of the cable, extending the service life and reducing the maintenance cost. Its advantages are gradually being recognized by more and more industry experts and design institutes, and the application prospect is very broad. This paper will introduce the properties, filling process and engineering application of oil-based sealing wax.

Abstract:Based on the correction and restoration project of a 6×20m prestressed hollow slab girder bridge, a synchronous jacking and sliding jack system is designed based on the characteristics of the hollow slab girder structure and the space under the beam. The three-way jacks are used to provide active correction force, drive the jacking and beam sliding, and realize the transverse correction and restoration of the beam. The key design points and construction technology of correction and resetting scheme are emphatically introduced. The engineering practice shows that the design is reasonable, the construction is economical and convenient, and the expected engineering effect is achieved, which can be used for reference and popularization for similar projects.