Efficient inelastic analysis of coupled shear walls using refined continuum medium theory: validation and application

Coupled wall systems consisting of wall piers connected with coupling beams form a very popular lateral force-resisting solution for tall buildings in high seismic regions. Elastic continuum medium theory offers fast preliminary analysis but cannot capture the progressive stiffness degradation that takes place as coupling beams yield under increasing seismic demands-a phenomenon crucial to capacity design and damage assessment. By contrast, the high computational cost of nonlinear response history analysis precludes this method from practical use in parametric studies and design optimization. This paper presents a Refined Continuum Medium Theory (RCMT) that fills this knowledge gap by embedding inelastic coupling beam behavior through degrading hysteretic models within the continuum framework. The methodology proceeds through iterative equilibrium using modified Takeda hysteresis, thus allowing tracking of Degree of Coupling (DoC) evolution as coupling beams progress from elastic to post-yield response. Wide-ranging validation against NLRHA for 40- to 60-story structures reveals that the proposed methodology attains high-fidelity accuracy-displacement profile RMSE < 5%, DoC evolution MAPE < 8%, and R2 > 0.92-while operating at a radically accelerated computational pace. Parametric sensitivity studies confirm method robustness across practical ranges of post-yield stiffness ratios (0.02–0.05), coupling ratios (0.40–0.70), and structural heights (20–80 stories). A 45-story design example illustrates the rapid evaluation of alternative coupling beam configurations, where RCMT identified near-optimal solutions subsequently verified through NLRHA. The method gives to practicing engineers an effective tool for preliminary performance assessment that allows for systematic design space exploration and optimization prior to final detailed analysis, supporting contemporary performance-based seismic design workflows for tall building structures.