According to the section size set in the tunnel excavation plan. This technology can ensure the accuracy of the size of the steel arch from the source, make the whole arc of the arch smooth after installation and molding, and ensure the structural stress performance of the arch.
Integral cold bending forming of steel arch frame
According to this scheme, the formed arch frame is cut into segments.
Steel arch frame segmented finished product
Machining and installation of connecting plate
The connecting plate of steel arch frame and I-beam are welded by carbon dioxide shielded welding, and the welding quality is good. Carbon dioxide shielded welding has the advantages of strong penetration, deep penetration, good weld formation, firm welding, strong crack resistance, small deformation after welding and simple operation.
Connecting plate processing machine tool
Finished connecting plate: accurate size and standard bolt hole shape.
Carbon dioxide shielded welder
welding operation
Full weld and good welding quality.
Installation of secondary lining reinforcement
The positioning of secondary lining reinforcement is a weak link in tunnel quality control. In order to improve the installation quality of secondary lining reinforcement, the following installation technology can be adopted to ensure that the spacing, row spacing and protective layer thickness of reinforcement meet the design requirements.
1, according to the design requirements, accurately process various specifications of steel bars, accurately control the position of embedded steel bars in the arch foot wall, and pay special attention to the source of accurate positioning of secondary lining steel bars. 2. Set the installation trolley and the positioning frame to position the steel bars, make full use of the connecting structural steel bars between standard floors, accurately control the spacing between the two layers of steel bars in the secondary lining, and ensure the accuracy of the circumferential position of the steel bars. 3, using fixture positioning, control the longitudinal spacing of the main reinforcement; Adjust the shape of steel skeleton by pulling wires. 4. The second lining reinforced protective layer adopts high-strength concrete pad as reinforcement measures to ensure that the thickness of reinforced protective layer is strictly controlled.
Locate the longitudinal spacing of the main reinforcement with slots, and weld the horizontal structural reinforcement for fixation.
Steel bars are constructed by standard size interlayer connection, and the spacing between two layers of steel bars in the secondary lining is accurately controlled.
Stay wire to adjust the position of reinforcement to ensure the smooth surface of reinforcement.
Use special trolley and positioning frame.
Installation of secondary lining reinforcement The location of secondary lining reinforcement is accurate, the pad is closely attached to the lining trolley template, and the thickness of protective layer is qualified.
The installed and formed secondary lining steel skeleton is stable and neat, and the line shape is smooth.
waterproof treatment
The hot-melt positioning device is used to fix the second lining waterproof board, and the hot-melt lining can be fixed at any position of the initial support and surrounding rock of the tunnel with nails. The waterproof board is welded on the hot-melt lining through the electric welding device, so that the waterproof board is closely attached to the initial support or surrounding rock, and the tightness is moderate, effectively reducing the void of the second lining.
Improvement of the end die structure of the second lining trolley. According to the design position, there is a reserved groove for middle water stop in the middle of the end die. End formwork and water stop shall be installed at the same time, and the water stop shall be fastened on the formwork with special bolts to ensure accurate and firm position.
Secondary lining concrete
Control the quality of raw materials, adjust the slump of concrete in real time, improve the vibrating technology, and strengthen the maintenance of formwork trolley, so that the surface of the second lining concrete after formwork removal is flat, dense, smooth and consistent in color, and the effect of inner reality and outer beauty is achieved.
Lining concrete curing
Watering curing of secondary lining concrete
Spraying concrete and sprinkling water for curing.
Cable trench and drainage ditch
The large steel formwork is used to cast the tunnel cable trench and drainage ditch on site, which well controls the line shape of the cable trench and drainage ditch, and the concrete surface is smooth and dense. The cover plates of cable trench and drainage ditch are made of plastic setting molds, and the vibration table vibrates. The cover plate has good appearance, stable size standard and convenient installation.
drainage ditch
Install cable trench and drain cover plate
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