Based on the traditional hanging basket cantilever construction of the prestressed concrete box girders, combined with the excellent shear capacity of the corrugated steel webs (CSWs), this paper introduces an improved cantilever construction method for long-span prestressed concrete (PC) girder bridges with CSWs, which is called the asynchronous-pouring rapid-construction (APRC). A remarkable change is that it uses the CSWs themselves as the main load-bearing members for supporting the hanging basket and girder segments. The equilibrium state of the new hanging basket system in the APRC method is optimized from the cantilever to a simply supported condition. Additionally, the dislocation construction of the top flange, bottom flange, and CSWs on three adjacent segments is accomplished simultaneously. Therefore, the construction efficiency is greatly improved because the number of construction platforms is increased to three compared with the single platform of the traditional hanging basket cantilever construction. In addition, it realizes the asynchronous pouring of the top and bottom concrete flanges in the same segment so that the pouring concrete has sufficient time to reach the required strength. Finally, by considering the longest prestressed concrete girder with CSWs in China, the whole construction process of the Fenghua River Bridge using the APRC method is systematically introduced.

Despite the construction of several curved prestressed concrete girder bridges with corrugated steel webs (CSWs) around the world; their shear behavior has seldom been investigated. Accordingly, this paper substitutes the lack of available information on the global elastic shear buckling of a plane curved corrugated steel web (PCCSW) in a curved girder. This is based on the equilibrium equations and geometric equations in the elastic theory of classical shells, combined with the constitutive relation of orthotropic shells. Currently, the global elastic shear buckling process of the PCCSW in a curved girder is studied, for the first time in literature, with an equivalent orthotropic open circular cylindrical shell (OOCCS) model. The governing differential equation of global elastic shear buckling of the PCCSW, as well as its buckling strength, is derived by considering the orthotropic characteristics of a corrugated steel web, the rational trigonometric displacement modes, Galerkin’s method and variational principles. Additionally, the accuracy of the proposed theoretical formula is verified by comparison with finite element (FE) results. Moreover, the expressions of the inner or outer folded angle and radius of curvature are given by the cosine theorem of the trigonometric function and inverse trigonometric function. Subsequently, parametric analysis of the shear buckling behavior of the PCCSW is carried out by considering the cases where the radius of curvature is constant or variable. This parametric analysis highlights the effects of web dimensions, height-to-thickness ratio, aspect ratios of longitudinal and inclined panels, corrugation height, curvature radius and folded angles on the elastic shear buckling strength. As a result, this study provides a theoretical reference for the design and application of composite curved girders with CSWs.

The utilisation of box girders with corrugated steel webs (CSWs) represents an innovative approach to bridge superstructure design that has garnered substantial popularity worldwide, with a notable prevalence in both Asia and Europe. Compared with traditional box girders, they avoid web cracking, improving the prestressing efficiency and bridge spanning ability. As an innovative box girder, a corrugated web can increase the cantilever length and transverse stiffness, and at the same time, it reduces the dead weight of the bridge deck. However, little research has been conducted on the mechanical properties of this novel spine-like box girder with CSWs, especially its transverse performance, although it has been used in many applications. In this paper, the effect of the web form on the behaviour of box girders is introduced. Therefore, three representative three-dimensional (3D) finite-element models (i.e., corrugated web box girder, flat web box girder, and ordinary equivalent concrete web box girder) have been established to quantitatively investigate the influence of corrugated web stiffness on transverse stress under the action of gravity and vehicle loads. Generally, significant differences in the mechanical performance of box girders with CSWs have been observed compared with conventional box girders with concrete webs. Additionally, parametric studies to investigate the influences of the corrugation dimensions (in term of the corrugation height, web thickness, panel width, web height and elastic modulus) on the transverse stiffness of such bridges are analyzed. The results show that a new stiffness formula can be put forward to consider the effect of web height, and a high-strength steel web needs to be developed urgently for box girders with CSWs in the near future. Overall, the results of this investigation can be used as a reference for transverse designing and segmental construction of similar projects.

Owing to the curvature of curved girders with corrugated steel webs, the inner and outer corrugation angles of the webs are different. For the local buckling behaviour of such webs, under the influence of different parameters, cases of panel lengths ratios were analysed in detail. Results showed that the average value of local buckling coefficients of curved corrugated steel webs was higher than straight ones. Based on Lindner's and El-Metwally's interactive theories, interactive buckling formulas for different panel aspect ratios were given. Additionally, considering the difference between elastic and yielding synthetic indices of curved webs, a buckling design formula was proposed by means of unequal synthetic indices. The finite-element values of local and interactive buckling were designed reasonably, and design parameters were determined through a large amount of analytical data. When the slenderness ratio was less than 1·5, the proposed design curve was found to be better than other available curves. Finally, buckling modes of straight corrugated steel webs in previous experiments were effectively separated by the given judgement formulas of different buckling modes. The percentage of local buckling in the experimental data was found to be highest, which formed a degenerated model compared with the proposed design curve.

The existing planning method of feeder automation (FA) of distribution network in mountain area doesn't consider the access of distributed generation (DG), and has no differentiated guidance on the actual line situation. Aiming at the status quo, a new planning method of FA of 10 kV distribution network in mountain area considering DG is proposed in this paper, based on the analysis of the main construction mode of FA and the influence of the access of DG. Aiming at the minimum of total annual cost of automatic configuration, the planning model of FA is established. With the cluster results of actual line, the optimal solution of the model in different situations is obtained, including the types of configuration scheme and the numbers of switches. Further, the recommendation table of automation planning is formed, which is Instructive. The example shows the method is superior in economy satisfying the reliability index.

Many advantages of curved box girders with corrugated steel webs (CSWs) are given in this paper, they have a lot of advantages such as light weight, high efficiency, engineering economics, assembly construction and aesthetic appearance. This type of structure combines steel and concrete materi- als properly, which improves the structural strength, stability and utilization efficiency of materials, and can effectively resist earthquakes, and realize assembly. The unique structural features of CSWs in curved box girders are pointed out, that is, the difference between the inside and outside folded angles. Based on cosine theorem and sum of angles, formulas of two different angles are proposed. Moreover, mechanics characteristics are given, which include three types of shear buckling modes, section distortion and longitudinal warping. Thus, the design of CSWs dimensions can be carried out through the buckling of CSWs in curved box girders, and the arrangement of intermediate dia- phragms of curved box girders with CSWs should be considered. Additionally, the transverse char- acteristics regularities of curved box girders with CSWs under different cases and different radius of curvature are obtained, respectively. Among them, two kinds of cases are the most unfavorable.