Numerical study on split base plate connection with concentric anchors between steel‐plate composite wall and concrete basemat

Abstract

Steel-plate composite (SC) walls can be connected to a concrete basemat using a base plate and a set of anchors eccentric to the wall. The base plate can be separated into two parts so that the concrete of the wall and basemat is cohesive, and thus, the wall can be manufactured more easily and economically. Additionally, compression and shear demand are directly transferred from infill concrete to concrete basemat.Another change in the base plate connection of available tested walls involves transferring anchors to the bottom of faceplates. As a result of this modification, the base plate is removed from the force transmission chain, and the force is transferred directly from the wall to the anchors. After presenting the design criteria for this type of connection, three test walls with concrete foundations were verified in LS-Dyna.The walls were modeled with a split base plate connection and concentric anchors, and then compared to other types of wall-basemat connections. Three rectangular sections were then chosen as benchmarks and modeled with three anchors of different sizes to evaluate the effect of this parameter on walls behavior. The design equations presented for the single base plate connection were found applicable to design split base plate connections. Then all walls were compared to the test wall-fixed base wall connection. Finally, the models were analyzed with elastic walls to determine whether the foundation is stronger than the wall. The split base plate connection with concentric anchors was found to be stronger than connected parts and can be an alternative to existing connections.concentric anchors, concrete basemat, rectangular steel-plate composite walls, split base plate connection | INTRODUCTION AND BACKGROUNDSteel-plate composite (SC) walls are introduced as a lateral force resisting system in ASCE 7. [1] SC walls consist of two steel faceplates with concrete fill between the plates, with or without boundary elements. Tie bars or a combination of tie bars and shear studs can be used to achieve the composite action between the plates and concrete fill. An SC wall can be used when a relatively large seismic demand on the walls leads to dense reinforcement and large thicknesses in conventional concrete shear walls or relatively large wall thicknesses of the web infill and boundary elements in special plate shear walls. [2] SC walls correct the defects of steel plate shear walls. [3]

Special all‐round fillet weld for anchor rods of base‐plate T‐stub connections

“…It is worth noting that the equivalent T-stub in tension was chosen because the tension in anchor rods is more critical than the compression. 11 Moreover, the test setup for loading T-stubs in compression and shear requires a concrete foundation, making the anchor rods and the fillet welds invisible and difficult to investigate. Besides the experimental work, the digital image correlation technique (DIC) was employed to capture the deformation of the specimen over the entire loading process.…”

“…Therefore, it is crucial to develop a new base‐plate T‐stub connection in which the base plate is not considered as a component resisting the applied loads. Vakili Sadeghi et al 11 conducted a numerical study to investigate the general behavior of steel‐plate composite walls with welded anchor rods positioned concentrically beneath the base plate so that the base plate could be separated into two parts to allow the concrete of the wall and the foundation to merge. They proposed four weld types to connect the anchor rods to the base plate.…”

“…Therefore, the fillet weld will be tested twice in one experimental specimen. It is worth noting that the equivalent T‐stub in tension was chosen because the tension in anchor rods is more critical than the compression 11 . Moreover, the test setup for loading T‐stubs in compression and shear requires a concrete foundation, making the anchor rods and the fillet welds invisible and difficult to investigate.…”