The construction technology of steel arch support mainly includes the following aspects:
Processing technology: The steel arch should be released on the flat steel plate before processing, and the arc and length should be controlled to ensure that the arch curve produced by processing is smooth and beautiful. During the machining process, the influence of factors such as increasing the size of the trolley template and the reserved deformation amount of the hole body excavation should be considered, and the arch radius should be appropriately increased during the segmentation processing to ensure the tunnel headroom size.
Connecting plate welding: Steel arch connecting plate adopts 280×142×16mm model, bolt connection assembly, riding seam welding firmly, welding seam should be full, no sand holes.
Arch installation: Steel arch installation should be carried out after the initial concrete shotcrete, longitudinal connection between each steel arch using a diameter of Φ22 steel rod, the length according to the actual site, determine the ring spacing of 1m. Each steel arch is connected by bolts, the connecting plate is tightly attached, and the connecting steel plate is 10mm thick.
Arch positioning: During the installation of steel arch, the point of arch clearance should be strengthened by technicians and inspectors. Multi-point control is adopted when the arch frame is set up, and each connecting unit should have a point position to control the arch frame clearance.
Construction quality requirements: The welding of steel arch frame processing shall not have false welding, and the weld surface shall not have cracks, welding bumps and other defects. The section size of steel arch should meet the requirements of strength, stiffness and stability.
Installation quality control: the steel arch should be perpendicular to the middle line of the tunnel, the deviation should be less than ±5cm, and the inclination of the steel arch should be less than ±2 degrees. The steel arch should be welded with the outcrop of bolt and steel mesh as much as possible to enhance its combined support effect.
Construction schedule management: The construction of steel arch support should follow the construction plan, centralized stacking, the following should be padded with sleepers to prevent rust, the loader is transported to the working face, and the manual with mechanical installation.
The above is the main content of steel arch support construction technology.
