Plastic Hinge Lengths in High-Rise Concrete Shear Walls

摘要

It is commonly assumed that the maximum inelastic curvature in a wall is uniform over a plastic hinge length (height) l_p equal to between 0.5 and 1.0 times the wall length l_w (horizontal dimension). Experimental and analytical results indicate that inelastic curvatures actually vary linearly in walls; however, the concept of maximum inelastic curvature over l_p can still be used to estimate the flexural displacements of isolated walls. Based on the results of nonlinear finite element analyses using a model validated by test results, an expression is proposed for lp as a function of wall length, moment-shear ratio, and axial compression. A procedure to account for the influence of applied shear stress on l_p is also presented. In high-rise buildings, walls are interconnected by numerous floor slabs, resulting in a complex interaction between walls with different l_w Longer walls generally have larger shear deformations near the base because their higher relative flexural stiffness and flexural strength attracts a larger portion of the total shear force. More slender walls correspondingly have larger flexural deformations near the base to maintain compatibility of total deformations at the floor levels. An expression is presented for estimating maximum curvatures in systems of walls with different l_p where the actual linear variation of inelastic curvatures must be accounted for.