Hydraulic inverting bridge formwork is one of the main components of the tunnel structure, it is the foundation of the tunnel structure. On the one hand, it is necessary to effectively transmit the formation pressure of the upper part of the tunnel to the underground through the tunnel side wall structure or the load on the road surface, and also effectively resist the reaction force from the lower layer of the tunnel. In fact, it is a kind of foundation beam (slab) that can bear the permanent load of the ground and the temporary load of the road (dynamic load).
For this reason, the stress state of the back arch is more complicated. Judging from the examples of traffic tunnel engineering diseases at home and abroad, due to the design and construction of the tunnel arch structure, the tunnel structure is unstable, the road surface settlement is cracked, and there are many examples of the disease caused by mud and mud. For this reason, it must be fine when applying the inverted arch structure, and its structure must meet the specifications and design requirements.
1. Processing of Hydraulic inverting bridge formwork
Each Hydraulic inverting bridge formwork is composed of two beam plates, each beam plate is welded by four I36b I-beams, the length of the I-beam is 12m, the distance between the I-beams is 20 cm, and there are 8 groups of intermediate connections with a spacing of 1. 5 m, every two I36b I-beams are welded with I16 I-beams to form a whole. The top of the beam is welded with ￠22 steel bars, the distance between the steel bars is 20cmm, and the bottom uses l5 cm wide and 10 mm thick steel plates to weld the four I36b I-beams into a whole.
2. The number of Hydraulic inverting bridge formwork is determined
The curing time of the concrete was determined to be 4 days to meet the driving requirements. The cycle time of the upward arch construction operation was 2 days, each cycle of construction was 9 m, and each hydraulic inverting bridge formwork was 54 meters per month. The average monthly advance of the palm face excavation is 120m. To match the progress of the excavation and the palm face excavation, at least 2 (4 pieces) Hydraulic inverting bridge formwork are required to meet the requirements.
3. Construction points of Hydraulic inverting bridge formwork
1. The trestle processing is carried out in strict accordance with technical disclosure, and the welding seam is full.
2. When the Hydraulic inverting bridge formwork is in place, pay attention to the flatness and width of the installation to meet the design requirements, to ensure that the vehicle traffic safety and vehicles with different wheelbases can pass the Hydraulic inverting bridge formwork.
3. The muddy water and residual concrete on the upper part of Hydraulic inverting bridge formwork should be removed in time to keep the upper part of the trestle clean.
4. The speed limit of vehicles passing through the trestle is 5 km/h. Construction under the trestle is strictly forbidden to ensure safe construction.