What issues should be paid attention to in steel support construction?

What issues should be paid attention to in steel support construction?

The steel support construction unit can choose the section length according to the feed length and construction process requirements, and assemble it on site according to the width of the foundation pit. After installation, the deviation of the center line should not be greater than 1/1000 and less than 20mm, and the installation time of the steel support should not exceed 12h.

Regarding the movable end and fixed end of the steel support, the construction unit can choose other methods according to the existing equipment and processing experience, but the stress requirements must be met. A preload jack should be set on one side of the steel pipe (the construction unit should plan and manufacture and process the jack according to the pre-axial force and the planned value of the selected jack) to preload the bearing. For specific axial forward force values, please refer to the relevant drawings.

When constructing supports of the same height on the same side section, all fixed ends must be placed and fixed at the same time. After installing the bracket, check the connection resistance of the node in time. After meeting the requirements, the jack should be used to preload the axial force to avoid damage to the product due to unbalanced stress in the same face section. The prestressed steel bar is loaded twice, each time 50% of the prestress is loaded, the axial force loss and horizontal displacement of the wall are observed within 12 hours after the initial prestress, and the pre-axial force is added to the planned value.