Research on Key Technologies for Large-scale Tensioned Membrane Replacement Construction

With the increasing demand for urban architectural renewal, the replacement projects of tensioned membrane structures due to material aging have become a tough challenge in the industry. There is an urgent need to establish a non-destructive, safe and green technical system for rapid replacement. This study targets the technical bottleneck in the non-destructive replacement of large-scale tensioned membranes and applies a “2+2+4” refurbishment process to the steel structure—namely, two stages of paint removal, two stages of grinding, and four layers of coating. During high-altitude operations, a three-dimensional protection system composed of an 8mm steel wire rope lifeline safety system, 17 protective nets, and hybrid lifting aerial work vehicles is utilized to ensure construction safety. An innovative non-destructive membrane removal technology with graded traction by mobile cranes is employed, which adopts a 25 tons mobile crane (18.7 m main boom) for graded traction. For the most unfavorable working condition where the hoisted load, counterweight, and two outriggers of the crane are in a straight line – involving a maximum hoisted load of 2.8 tons with a lifting radius of 16 meters – the outrigger load is decomposed through mechanical modeling (N_max=13.76 tons), and the foundation bearing capacity is calculated (22 kPa). It is verified that this bearing capacity is less than the design bearing capacity of the concrete pavement and subgrade (700 kPa, 200 kPa), so as to ensure lifting safety. The dismantling is carried out in the sequence of steel cap → edge mast (temporarily pulled by 25 tons mobile cranes) → membrane material → middle mast → framework to avoid structural damage.In the practical application of the 2340 m² membrane structure replacement project at the Guangzhou Oceanarium, efficient construction was completed in 83 days (41% shorter than traditional processes), with a 100% recovery rate of skeleton materials (full reuse of steel structures) and an 85% recovery rate of waste membrane materials, achieving a 23% reduction in comprehensive costs. It meets the requirements of green construction, verifying the significant effectiveness of this technical system in ensuring high-altitude operation safety, maintaining structural mechanical balance, and improving construction quality, thus providing important references for similar projects.