Seismic impact between adjacent torsionally coupled buildings

• Published in: Soil dynamics and earthquake engineering (1984) 2019-02, Vol.117, p.81-95
• Main Authors: Farahani, D., Behnamfar, F., Sayyadpour, H., Ghandil, M.
• Format: Article
• Language: English
• Subjects: Aseismic buildings; Building codes; Buildings; Clear distance; Consistent earthquakes; Earthquakes; Eccentricity; Frame structures; Nonlinear dynamic; Nonlinear response; Plastic properties; Plasticity; Pounding; Seismic activity; Seismic design; Seismic response; Stiffness; Three dimensional models; Torsion
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2018.11.015

The problem of seismic impact between torsionally coupled multi story moment frame buildings is investigated in this paper. Five pairs of adjacent structures spaced at various separation distances are considered. The buildings are 4–10 stories in height. Although a common plan being symmetric with regard to lateral stiffness is considered, a mass eccentricity variable from zero to 30% of the plan dimension is assumed. By three-dimensional modeling of the nonlinear torsional buildings having common story elevations, the seismic pounding happen anywhere along the adjacent buildings edges. Effect of impact and torsional eccentricity are studied by comparison of nonlinear dynamic responses of buildings at different clear distances under 11 consistent earthquakes. The responses include pounding forces at stories, story drifts, story shears and plastic hinge rotations. It is shown that how pounding incidents increase for larger eccentricities and how pounding occurs even at the clear distances prescribed by seismic design codes. The combined effect of torsional eccentricity and pounding results in amplifying the nonlinear response of structure especially for the peripheral frames. •Shear in upper stories increases due to pounding mostly for smaller eccentricities.•Torsional coupling of adjacent buildings makes them to impact at the corners.•Impact at the corners acts like an amplification factor for the torsional response.•Story torsion and pounding make peripheral frames to be the most critical ones.•Perimeter frames under torsion need special attention even at code clear distances.