Analysis, design & installation of vibration isolation for lightweight helipads: a case study

Abstract

The heliport isolation aims to mitigate the transmission of helicopter-induced vibrations to the building structure during approach, landing, and take-off by introducing vibration isolators at the supports of the heliport structure. As a case study, this paper presents the design and manufacturing steps for the installation of a vibration isolation solution for two lightweight helidecks installed on the rooftop of an existing medical center building. Design of a very high-performance isolation system for a lightweight helideck, requires a series of stability checks under various load conditions. In practice, the primary challenge is to control the substantial differential deflection of the helideck, which is supported by relatively soft isolators, during approach and landing conditions. The solution delivered was a prefabricated spring box comprising essential components such as failsafe and uplift restraints to deal with the challenging aspects of the isolation of lightweight helidecks. Certainly, a collaborative effort between the isolation solution provider and the helideck supplier facilitated a progressive design process aimed at meeting stringent acoustic performance requirements and addressing the complex functionality of a lightweight helideck. The paper also discusses the challenges and best practices encountered during the production and installation of the system.