The high- and low-temperature resistance of an air-supported membrane structure for an excavation pit refers to its ability to maintain its original mechanical properties, sealing effectiveness, and structural stability when subjected to high temperatures, low temperatures, or frequent temperature fluctuations. These structures are typically composed of a high-strength fabric base coated with a polymer; the material's temperature resistance depends on factors such as the type of base fabric, the composition of the coating, the thickness of the membrane, and the manufacturing process. In hot summer conditions, the membrane is continuously exposed to solar radiation and external heat, which can lead to material softening, dimensional changes, degradation of the coating, or a reduction in the strength of the seams. Furthermore, if ventilation within the structure is inadequate, rising internal temperatures can negatively impact the working environment for construction personnel. Consequently, during the material selection and structural design phases, it is essential to account for local peak summer temperatures, solar radiation intensity, and potential heat accumulation. This involves selecting membrane materials with superior heat resistance and integrating ventilation, shading, or cooling systems to regulate the internal environment. For critical areas-such as heat-welded seams, edge attachments, and anchor points-special attention must be paid to differential material deformation caused by temperature changes, ensuring that localized stress concentrations do not lead to cracking, loosening, or a loss of sealing integrity. Technical guidelines for such air-supported structures emphasize membrane performance, structural safety, and the control of the operational environment as key aspects of design and management.
In low-temperature environments, the cold resistance of an air-supported structure for an excavation pit is equally critical to the quality of its installation and the reliability of its operation. At low temperatures, some polymer coatings may lose flexibility or become brittle; subjecting them to forced stretching, folding, or handling under these conditions can easily damage the membrane surface and, in severe cases, compromise the integrity of seams and connection points. Moreover, during winter construction, the structure may be simultaneously affected by low temperatures, snowfall, and significant diurnal temperature variations. Beyond evaluating the low-temperature performance of the membrane material itself, it is necessary to assess the structural stress distribution, drainage capabilities, and snow-mitigation measures to prevent the accumulation of snow or localized ice, which could otherwise increase the load on the structure. For air-supported structures used over excavation pits in cold regions, the appropriate membrane material must be selected based on the local climatic conditions. The reliability of the product within the specified temperature range should be verified through material performance testing, seam strength testing, and, where necessary, temperature cycling tests. During actual use, installation, maintenance, and storage must be carried out in accordance with the temperature ranges stipulated in the product's technical documentation; specifically, forced deployment or repair should be avoided under unsuitable, low-temperature conditions. It should be noted that there is no universal temperature-resistance standard applicable to all air-supported structures; the specific operating temperature range must be determined based on membrane material test reports, product technical documentation, and project design requirements. Furthermore, the temperature range that the membrane material itself can withstand is not the same as the temperature range suitable for personnel working inside the structure-the latter must be regulated through ventilation, heating, or cooling systems.