Improvement of Staircases Vibration Serviceability to Human Ergonomics: A Case Study

Abstract

Contemporary, slender and lightweight monumental staircases are often highly susceptible to resonance phenomena, due to typically low fundamental frequencies, which can considerably amplify their responses, raising major serviceability problems and causing discomfort and unsafety concerns to its users. This paper presents a case study of a low fundamental frequency steel staircase with known high levels of vibration since the beginning of its construction, in which various improvement solutions were proposed in order to increase its vibration serviceability. In total, six improvement measures were proposed, being tested using the Finite Element (FE) software SAP2000. The initial FE staircase model was first calibrated with the vibrations experimentally measured on the real staircase. Then, the original FE model was modified with the six improvement measures and the resulting vibrations were compared with those initially obtained and the acceptable limits suggested by the design guide SCI P354, to verify their viability. The most efficient numerical improvements were those that increased the staircase fundamental frequency, off the range of frequencies excitable by pedestrians walking.