Abstract:This paper points out the structural defects of the cable body through the analysis of the main structural characteristics of the pressure distributed anchor cable, and further puts forward the application of the new technology to improve the structure of the prestressed anchor cable, and overcome the inherent defects of the original pressure distributed anchor cable structure. Under the same anchoring mechanism, the author proposes that the anchorage anchorage point can be designed according to the anchoring needs, so that the prestressed anchor cable can have a certain stress release function, which can release the excessive deformation of the anchored rock and soil mass, effectively protect the stress level of the anchor cable, and improve the safety and durability of the anchor cable. Through engineering application, it is proved that the structure is reasonable, the anchorage is convenient, and the reliability of construction is greatly improved.

Abstract:The middle route of the South-to-North Water Transfer Project is an extremely large water transfer project in China, with many cross-building, complex engineering environment and geological conditions. The durability design of the engineering structure is an important guarantee for the lasting and safe operation of the project. In this paper, Nansha River inverted siphon, a large canal crossing structure in Hebei Province of the Middle Route of the South-to-North Water Transfer project, is selected and the basic idea of durability design is briefly introduced. It provides reference for the design of similar buildings.

Abstract:With the application of large diameter steel rod in bridge more and more widely, it is necessary to understand the mechanical properties of 40Cr material used in steel rod, ensure the operation safety of bridge, and provide technical reference for the design of late pull rod. This paper studies the sampling test from the same large-diameter bar, respectively without heat treatment, positive heat treatment, tempering heat treatment and normalizing + tempering heat treatment and other states of sampling test comparison, at the same time, from the different hardness after tempering and whether the forging process is used, respectively, the mechanical properties of 40Cr material have a further understanding, and finally through the metallography group The causes of unqualified impact properties are obtained by weaving comparison, which provides help for in-depth understanding of 40Cr material properties.

Abstract:Wire rope is gradually widely used in pedestrian suspension bridge, but because the elastic modulus of wire rope is relatively small compared with the parallel wire rope strand, it brings a series of problems to the design and construction. Combined with the practical application of Nanping Jiufeng cable Bridge, this paper introduces the design ideas and precautions of the derrick, main cable strand, cable clip and cable saddle respectively. Combined with the construction methods and steps of the bridge, it is further explained, which has certain reference significance for the design and construction of similar suspension Bridges.

Abstract:The influence of surface grease on the binding force of epoxy sprayed steel strand and cement mortar was studied by comparing the tensile strength of epoxy sprayed steel strand under five different conditions. The experimental results show that the surface grease of epoxy sprayed steel strand has a certain effect on the binding force of cement mortar. The steel strand with more grease on the surface has a poor binding force, while the steel strand with clean grease on the surface has a better binding force. In the actual process of unbonded prestressing tendons, the surface grease of epoxy steel strand should be cleaned to avoid affecting the tensile properties of unbonded prestressing tendons.

Abstract:The concreting of long span string beam is a new structure form, but the construction control of string beam is always a difficult problem in the construction field. In this paper, the key technologies in the construction process are studied, the accurate analysis model is established, the out-of-plane instability of the string beam is analyzed, and the displacement control and cable force control methods in the construction process are proposed.

Abstract:With the wide application of corrugated steel webs in the main beams, the first cable-stayed bridge with corrugated steel webs without backcables was born in China, Qinshihua River Bridge, which used a variety of prestressed structural systems and had the advantages of light dead weight of the main beams, good seismic performance, high prestressed efficiency and avoiding web cracking. But at the same time, it also brings some difficulties to the construction and monitoring. In this paper, combined with the construction situation of Qinshui River Bridge, some main construction techniques of superstructure are introduced respectively for the reference of similar bridge construction.

Abstract:As a new active reinforcement technology, prestressed carbon fiber plate reinforcement makes full use of the high strength and high elastic properties of carbon fiber, which can effectively improve the deformation of structural members and increase the bearing capacity of structures. This paper introduces the construction technology and key points of strengthening T-beam bridge with finished prestressed carbon fiber plate products developed and produced by Liuzhou Overem Machinery Co., LTD. The engineering practice shows that the strengthening construction method is effective, the construction process is simple, the period is short, the impact on the bridge floor traffic is small, the cost is economical, and it can be used for the design and construction of prestressed carbon fiber plate reinforcement of similar beam Bridges Provide reference.