Fabrication of capsule-like inflatable woven fabric used for tunnel plugs

Considering safe and continuous operation of the subway tunnel, apart from the conventional drainage system, the entrances or exits of tunnels generally are designed to install special devices to block the influx of either floods due to sudden storms or harmful gases caused by terrorist attack. Traditional devices include metal plates or sandbags. In recent years, researchers have invented textile-based capsule-like inflatable device to replace the traditional devices because the new one can be flexibly located in the tunnel, capable of blocking fluids completely, light-weight and low cost. However, the fabrication of capsule-like textile structure has been seldom discussed in the literature. The capsule-like textile structure is either created by fabric weaving followed by sewing for the capsule form, which may result in unevenness of stress distribution due to existence of seams in the structure, or produced by expensive and specially designed weaving equipment. This paper is to explore two different fabrications of capsule-like textile structure for the purpose that the device is evenly structured and can be produced in one step with conventional weaving loom. The techniques of fabrication with trapezoid-formed reed as well as the application of double-layered structure have been investigated. The contour of spherical crown of capsule-like structure is well in line with calculated values.