UBC Theses and Dissertations
Plastic hinge length in high-rise concrete shear walls Bohl, Alfredo Guillermo
The flexural displacement capacity of a concrete shear wall depends on the length of the plastic hinge. Typical building codes and several researchers recommend the use of an equivalent plastic hinge length at the base equal to half the wall length. However, the plastic hinge length is also influenced by parameters other than the wall length. There are currently no recommendations on what should be the plastic hinge length for parallel walls of different lengths in a high-rise building. A parametric study was conducted to investigate the parameters that affect the length of the plastic hinge in concrete walls. The walls were analyzed using program VecTor2. The analytical model was validated with tests results performed on wall specimens. The results obtained show that the inelastic curvatures vary linearly over the plastic hinge length. The shape of the strain profile in slender walls after cracking depends on the amount of reinforcement. Longer walls have larger plastic hinge lengths than shorter walls. Compressive axial loads reduce the plastic hinge length, tensile axial loads have the opposite effect. A simple shear model was proposed to estimate the increase in plastic hinge length when the shear stresses are high. Walls of different lengths interconnected by rigid slabs at various levels have different curvature distributions and plastic hinge lengths. The curvatures in the longer wall do not change whether it is alone or combined with a wall of shorter length. The shorter length wall is subjected to larger curvatures at the base when it is combined. A simple model was proposed to predict the maximum curvature in the shorter wall.
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