An Overview of Ponding in Tensile Membrane Structures

Tensile membrane structures (TMS) are efficient and aesthetically pleasing systems that are widely used for various long-span applications. The predominant design consideration for TMS is to prevent the tearing of the membrane fabric under external loads such as wind or snow. However, design considerations such asponding are also crucial for maintaining the safety, functionality, and durability of these structures. Ponding refers to the accumulation of water on the membrane surface, causing additional deformation and increased loading on the fabric. In TMS design, ponding is mitigated by ensuring that an adequate slope is provided,to avoid water or snow accumulation, by adjusting either the boundary conditions or the applied prestress, or both. However, seeding events such as heavy rainfall or snow, reduction in prestress due to creep, improper maintenance, etc. can lead to progressive ponding. There have been several incidents of small-to-large-scaleTMS failure due to ponding, which show the real-life implications of this problem. The objective of this work is, therefore, to provide an introductory study on the effects of ponding on TMS, including the development of design strategies and an examination of the various seeding events. An integrated framework is developedin order to assess different TMS for ponding based on code guidelines. The susceptibility of different TMS shapes to failure by tearing or by ponding is demonstrated through different case studies, covering both basic and complex shapes.