Wind-Induced Response and Equivalent Static Wind Loads on Single-Layer Saddle-Shaped Shells

Abstract

Saddle-shaped roofs are one typical kind of large span roofs, but there are few studies on the equivalent static wind load (ESWL) of saddle-shaped roofs, which is important for structural design. This study conducts wind pressure measurements of saddle-shaped roofs with three typical rise-span ratios (f/S=1/6, 1/8, 1/12) by wind tunnel tests. Subsequently, the influences of wind and structural parameters on dynamic responses and ESWLs are investigated for 81 single-layer saddle-shaped shells with different structural stiffness, including rise-span ratio, span length, roof mass, and incoming mean wind velocity. The results show that the most unfavorable wind directions of the peak structural responses for single-layer saddle-shaped shells are 60° and 90°, as well as the axisymmetric wind directions corresponding to these two wind directions, i.e., 120°, 240°, 270°, 300°. Finally, a simple fundamental vector is proposed to express the multitarget ESWLs for single-layer saddle-shaped shells to reproduce multiple peak responses at the most unfavorable wind directions. Through parametric analysis, mean pressure coefficients of roof zones are proposed. Within the investigated parameter ranges, the fluctuating ESWL coefficients are expressed as the functions of the reduced structural frequency at the most unfavorable wind directions, which is very convenient for structural engineers to determine the wind loads on main force resisting structural systems.