On April 29, China's first "air-cushion type" foundation pit air membrane in the western region was successfully applied in Sichuan. The project is located within Sichuan Provincial People's Hospital and is currently in the foundation pit construction stage. The foundation pit excavation area is approximately 8,175 square meters, with a maximum excavation depth of about 22.4 meters underground, making it an ultra-deep foundation pit construction project in the building construction field.

The "air-cushion type" foundation pit air membrane in use. Photo courtesy of China Construction Eighth Engineering Division.

Walking into the construction site, one side features a rising and billowing silver "hot air balloon," while the other side is covered with a dense giant "green blanket." The "air-cushion type" foundation pit air membrane and the dust-proof sky curtain combine perfectly, erecting a green "dome" over the project construction site. Because the project is closely surrounded by existing outpatient and inpatient buildings, there is a large flow of people and high sensitivity to noise and dust. "To minimize the impact of construction on the diagnosis and treatment environment and medical order within the hospital, we formulated and implemented a construction plan combining the 'air-cushion type' foundation pit air membrane with a dust-proof sky curtain according to local conditions, reducing adverse effects such as dust and noise to a minimum and ensuring the normal operation of work and life for the hospital's medical staff and patients," said Gong Yu, project manager of China Construction Eighth Engineering Division, the project contractor. He stated that the foundation pit air membrane adopted by the project is the first double-layer "air-cushion type" inflatable membrane applied in foundation pit construction at a construction site in China's western region, and is a new green construction technology that combines dust prevention, noise reduction, energy conservation, fire resistance, and intelligence.

Rendering of the Comprehensive Scientific Research Building project of Sichuan Provincial People's Hospital. Photo courtesy of China Construction Eighth Engineering Division.

The air membrane foundation anchoring components use an angle steel connection method, which can evenly distribute the uplift force of the air membrane onto the ground beams, enabling the fastest installation and disassembly of the air membrane. Gong Yu stated that the project also adopts a fully intelligent control system called PLC, which can make the operation of the air membrane "smarter." In addition, the air membrane is equipped with a standard emergency backup system. Once a power outage or power supply failure occurs, the intelligent control will automatically switch to the backup generator to ensure continuous and stable operation of the air membrane. At the same time, the air membrane sky curtain also provides construction workers with a comfortable working environment with constant temperature and humidity, protecting workers from adverse weather such as wind, rain, and high temperatures, and greatly safeguarding the occupational health of workers. "Compared with traditional 'air-supported type' foundation pit air membranes, the double-layer 'air-cushion type' foundation pit inflatable membrane has stronger safety and stability performance, and its effects on thermal insulation, dust reduction, and noise reduction are also significantly improved compared with traditional air membranes," said Gong Yu. The membrane material uses a new type of PVDF building material that is high-strength, durable, fire-resistant, and resistant to high-temperature ultraviolet radiation. There is an interlayer between the inner and outer membranes, and it has a hollow structure, providing better sound absorption and insulation as well as thermal insulation.

The giant "green blanket" dust-proof sky curtain at the construction site, with the white "air-cushion type" foundation pit air membrane above. Photo courtesy of China Construction Eighth Engineering Division.

It is reported that the Comprehensive Scientific Research Building project of Sichuan Academy of Medical Sciences · Sichuan Provincial People's Hospital mainly includes an underground garage, equipment rooms, radiotherapy department, surgery area, clinical laboratory, pathology department, ICU, etc., and is expected to be completed by the end of 2026.