A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Lap Splices in Unconfined Boundary Elements
Because lap splices are believed to limit frame toughness, they are not used near critical sections of frames that are required to resist earthquake demands. The most salient conclusions from the data obtained in our tests are: * The beam test results were not affected by the shape of the stress-strain curve (the presence or absence of a well-defined yield plateau) in the longitudinal bars, suggesting that bar stress is a more critical factor affecting splices than bar strain; * Comparisons of the responses of the beam and wall tests confirm that the strength of a lap splice is sensitive to the moment gradient over the length of the splice. Because the bases of most structural walls will be subjected to moments with small gradients, results from tests of lap splices in scaled walls cannot be projected directly to full-scale walls. While peak bar stress and drift capacity increased with increases in transverse reinforcement ratio, these increases were offset almost completely by reductions in the clear spacing between spliced bars, which can occur easily during construction; and * Because factors such as spalling and displacement reversals are bound to reduce further the drift capacity of walls, the observed drift capacities suggest that structural walls with unconfined lap splices at their bases do not have the toughness required to survive the demands associated with strong ground motion caused by earthquakes.
Lap Splices in Unconfined Boundary Elements
Because lap splices are believed to limit frame toughness, they are not used near critical sections of frames that are required to resist earthquake demands. The most salient conclusions from the data obtained in our tests are: * The beam test results were not affected by the shape of the stress-strain curve (the presence or absence of a well-defined yield plateau) in the longitudinal bars, suggesting that bar stress is a more critical factor affecting splices than bar strain; * Comparisons of the responses of the beam and wall tests confirm that the strength of a lap splice is sensitive to the moment gradient over the length of the splice. Because the bases of most structural walls will be subjected to moments with small gradients, results from tests of lap splices in scaled walls cannot be projected directly to full-scale walls. While peak bar stress and drift capacity increased with increases in transverse reinforcement ratio, these increases were offset almost completely by reductions in the clear spacing between spliced bars, which can occur easily during construction; and * Because factors such as spalling and displacement reversals are bound to reduce further the drift capacity of walls, the observed drift capacities suggest that structural walls with unconfined lap splices at their bases do not have the toughness required to survive the demands associated with strong ground motion caused by earthquakes.
Lap Splices in Unconfined Boundary Elements
John N Hardisty (author) / Enrique Villalobos / Brian P Richter / Santiago Pujol
2015
Article (Journal)
English