Experimental Study and Comparative Analysis of a Geiger-Type Ridge-Beam Cable Dome Structure

摘要

Cable domes have widely been used in membrane-roof structures in recent years. A broader range of applications are expected if rigid-roof cable dome structures can be implemented. This study focuses on the static behavior of a new typed Geiger-type ridge-beam cable dome structure (Geiger-type RBCD). By changing the ridge cables of the conventional cable dome to hinged ridge beams, this structure can potentially support heavy rigid-roofing systems. A 6-m specimen is built and tested to investigate the static behavior of Geiger-type RBCD in full-span and half-span uniform loading conditions, and a finite-element model is utilized to compare the experimental results. The modified fractional-step finite-element method (FSFEM) is then introduced to obtain the proper structural parameters and initial pretensions of the conventional cable dome, suspen-dome, and Geiger-type RBCD structures. Based on the modified FSFEM, parametric studies of self-weight, support reactions, initial pretensions, and static behaviors of these three structures are conducted. The results show that the Geiger-type RBCD combines the characteristics of increased local stiffness attributed to its similarity to the suspen-dome, and good integrity characteristics attributed to its similarity to the conventional cable dome. This renders it capable of resisting relatively larger roof loads with fewer support requirements and tensioning apparatuses. Meanwhile, the use of ridge beams in the Geiger-type RBCD significantly reduces the pretension level, provides a relatively higher emergency capacity for the entire structure, and makes the Geiger-type RBCD able to meet the mechanical requirements of various loading cases.