11.15: Seismic behaviour of single layer cylindrical lattice steel shells

Abstract

Cylindrical lattice shell structures are commonly used in many applications such as in train stations, gymnasia, and sports halls. In comparison with their behaviour and design under gravity loading, their behaviour under seismic loading has received less attention, particularly in terms of the development of practical design procedures. Current European codes of practice lack specific guidance on the seismic design of these shells. In this paper, the salient considerations influencing the seismic response of single layer cylindrical lattice shells are examined. The effect of key geometric parameters such as the rise to span ratio, length to span ratio, inter-element angles, as well as the structural mass, on the characteristic natural periods and corresponding vibration modes are investigated using the finite element program OpenSees for two typical situations of boundary conditions. The influence of these parameters on the axial forces and bending moments in the members when subjected to the horizontal and vertical components of an earthquake is also assessed. The response is evaluated in the linear and nonlinear ranges, including representative time history analyses, with due consideration of both material and geometric nonlinearities. The results provide an insight into the main factors that govern the seismic behaviour of single layer cylindrical lattice shells, with a view to supporting the development of practical design and assessment procedures for this structural form.