The membrane installation process consists of four stages: membrane unfolding, connection and fixation, hoisting into place, and tensioning into shape. Each stage has its own unique installation techniques and construction precautions. Today, Zhengzhou Membrane Structure Engineering Co., Ltd. is sharing some daily construction tips to summarize the key points for membrane material installation.
Prior to unrolling the membrane, lay temporary fabric on the platform to protect the membrane material from damage and ensure cleanliness. Strictly unfold the membrane in the predetermined order. Before opening the packaging, check the markings on it, confirm the installation location, and unfold it in the marked direction, avoiding unnecessary movement of the membrane within the site. When walking on the unrolled membrane surface, wear soft-soled shoes and do not carry any hard objects to prevent scratches on the membrane.
After deploying the membrane on the platform, connect and secure the membrane material to the cables using clamps. The specifications of the clamps and the spacing between them should be installed strictly according to the design requirements. For membranes that are hoisted into place in one go, the clamping bolts and nuts must also be tightened in one go.
Currently, the suspension membrane structure is mostly installed using the multi-point overall lifting method, which involves modifying a mature overall "lifting" technique for use in the construction process of this flexible structure. This process requires synchronization throughout. During the lifting, the ascending speed and distance of each lifting point are controlled to ensure even force transmission across the membrane surface.
The membrane can be divided into several work blocks according to its plane position, with each block utilizing the multi-point integrated hoisting technique. The entire block is hoisted into place. If the whole-lift technique is used, it requires more equipment and personnel, and a longer preparation period. By employing the block hoisting method, the entire membrane is divided into five work blocks: Blocks 1 & 2, 3 & 4, 5 & 6, 7 & 8, and 9 & 10. The seven lifting points of each block are hoisted simultaneously. Once all the membranes reach the designed height, the blocks are connected in the air, showcasing their obvious advantages. Throughout the installation process, special attention must be given to prevent excessive swaying of the membrane under wind loads.
④ Tension forming is a crucial step in the entire membrane structure construction process, with the effectiveness of the project hinging on whether the tension meets the design specifications. When the supporting structure is a rigid boundary, the application of pre-tension requires special construction methods. For flexible boundaries, the magnitude of pre-tension can be adjusted by modifying the position of the struts. In tensioned cable membrane structures, the pre-tension of the membrane material is provided by the cables. The entire tensioning process essentially involves tensioning various cables to their predetermined stress levels. During tensioning, it is essential to determine the sequence and magnitude of batch tensioning, control the tensioning speed, and establish the over-tensioning values based on the material's characteristics. The tensioning process can be a step-by-step adjustment of cable pre-tension to reach the design values, or a simultaneous tensioning of the entire structure. Construction records should be made for tension values that require control, as well as tensioning travel records for those that do not.
