Abstract:The turning construction process of Yabunsha Bridge integrates vertical turning and level turning, and the weight of single turning system reaches 13,685 tons, which creates a new record for the turning construction of large-span arch bridge in China. This paper discusses the process and construction technology of the bridge's steel pipe arch rib vertical turn and flat turn.

Abstract:This paper analyzes the reasons for the gradual increase of torque during the leveling process of Dulaying Bridge, and concludes that frictional heat generation warms up the drag reducing coating and makes it fail as the main reason.

Abstract:This paper introduces the design of the transformation process, structural characteristics of the transformation structure, monitoring and control of the whole process of construction, traffic test, and the compression bar stability model test for the columns on the particularly slender arches on the special highway for external transportation of the Three Gorges Project, for the two bridges with a clear span of 160m, which were constructed by the transformation method. The paper describes the experience of participating in the practice of the two bridges and puts forward suggestions.

Abstract:On the basis of summarizing the advantages and disadvantages of existing prestressing concrete technology, the concepts of pre-bending double prestressing composite beam, pre-bending prestressing steel reinforcement concrete, pre-bending non-bonding prestressing concrete, and cross-tensioning prestressing concrete technology are proposed. Among them, the cross-tensioned prestressed concrete technology combines good usability, economy of materials and simplicity of construction, and has good technical and economic benefits and prospects for popularization and application.

Abstract:The application of cross-tensioning prestressing technology in T-girder bridges, box girder bridges and hollow slab bridges and its technical characteristics are introduced, and it is proved that the application of cross-tensioning prestressing technology in these three structural types is reasonable and feasible, and obvious technical and economic benefits can be obtained.

Abstract:This journal was published in 1999, Issue 3 and Issue 4 of this author's article "pressure type anchor cable and load dispersal type anchor cable in the application of reinforcement engineering" and "analysis of anchor cable type", now should be part of the readers' request, by the author to re-arrange, enrich the relevant content of the verification of the engineering application of a variety of anchor cable structure is analyzed, described. This article will be published twice in this magazine for the benefit of readers.

Abstract:Aiming at the problems of using full-length bonded anchors in China's tunnel projects, this paper adopts the spatial axisymmetric finite element program ASFEM to calculate and analyze the interrelationships between anchors and surrounding rock, and arrives at the following two conclusions: 1. It is infeasible to use the pull-out test to check the quality of the full-length bonded anchors. Existing codes, regulations, standards or technical guidelines, the results of the pull-out test as a comprehensive indicator for assessing the quality of anchor rods, and even the provisions of the pull-out force of 50kN is considered to be qualified is theoretically incorrect, which leads to harmful results in engineering practice. Such provisions should be revised as soon as possible.2. At present, mortar anchors without pads and anchor heads are widely used in domestic tunnels, although their structure is simple and easy to install, they often lead to destabilization of the surrounding rock due to their insufficient supporting capacity. Additional pads and anchor head can improve the rod stress conditions, enhance its support capacity, should vigorously promote the mortar anchor with pads and anchor head. Especially for the soft rock, the pad and anchor head is a very necessary part of the anchor.

Abstract:In this paper, by analyzing the distribution of shear stress caused in the cemented section when prestressing is applied to cemented anchorage anchor cables (rods), a new process is proposed for the use of segmental grouting and graded tensioning in grouting and tensioning construction of large-tonnage prestressed anchor cables (rods). Thus improving the tensile capacity of anchor cable (rod).