Abstract: Limited by weight and volume, the transportation and on-site installation of steel bifurcation in the diversion system of pumped storage power station have become a big problem in the construction of the project. According to the needs of the installation and construction of large 800 MPa steel bifurcation in the complex environment, combined with the characteristics of the transportation and installation in the tunnel, the unloading of steel bifurcation is carried out by using the bridge crane between the installation of underground powerhouse. The hoisting up-anchors and sliding trolley arranged in the tunnel are used to place and install the steel bifurcation, which solves the difficulty of hoisting and installing the large turnout pipe in the tunnel and has positive significance in saving the project cost and reducing the construction risk. In this paper, the construction technology of steel bifurcation is described under the complex conditions in pumped storage power station. Detailed description of steel bifurcation construction layout, assembly, site transportation and installation and other construction points, provide a feasible idea for the development of other similar projects.
Abstract: Limited by weight and volume, the transportation and on-site installation of steel bifurcation in the diversion system of pumped storage power station have become a big problem in the construction of the project. According to the needs of the installation and construction of large 800 MPa steel bifurcation in the complex environment, combined with ...Show More
Abstract: Within the field of sediment transport dynamics, there is an emphasis on the need for providing and improving simplified analytical solutions from which the findings can be extended upon. Typically, solutions have been developed from the understanding and incorporation of vertical velocity components/distribution; however, there remains opportunity for analytical enhancement. Under uniform open channel dilute sediment laden flow conditions, the type II concentration profile reflects the maximum concentration at a distance from the bed. To analytically depict the type II profile, it is essential to describe the vertical velocity components acting within the flow hydrodynamics. Yet, the impact of bed roughness on the vertical velocity distribution influencing a sediment particle has not been articulated. Hence, in this research, the impact of bed roughness is incorporated into the vertical velocity distribution to formulate the lift force acting upon a particle, to provide a sediment concentration solution. The proposed analytical vertical velocity distribution solution is validated against existing formulations, followed by the proposed sediment concentration being validated against existing solutions. Here, the results indicate that analytically incorporating the bed roughness alongside the secondary current induced vortices provides a lift force solution that can depict the type II concentration profile. Under relatively low shear velocity, increasing the sediment diameter allows for a clearer depiction of the near surface region and profile curvature. Furthermore, the proposed sediment concentration solution can accurately depict the near surface region, curvature of concentration, and maximum concentration under relatively large shear velocity data. Importantly, under conditions where both the shear velocity and sediment diameter are relatively large, the maximum concentration is captured with greater accuracy; however, the curvature of the profile and the near surface region accuracy are hindered. It is to be noted, that due to the formulation of the proposed velocity distribution the accuracy of the solution towards the bed decreases due to instability caused as the characteristic depth decreases to zero.
Abstract: Within the field of sediment transport dynamics, there is an emphasis on the need for providing and improving simplified analytical solutions from which the findings can be extended upon. Typically, solutions have been developed from the understanding and incorporation of vertical velocity components/distribution; however, there remains opportunity...Show More