The tunnel lining jumbo has low cost, high construction efficiency and good effect. It is mainly used in the construction of highways and various tunnels. Tunnel lining trolleys mainly include simple lining trolleys, fully hydraulic automatic walking lining trolleys and net-frame lining trolleys. Full hydraulic lining trolley can be divided into side-top arch type, full circle needle beam type, bottom mold needle beam type, full circle travel type, etc. So, what are the structural characteristics of the tunnel lining trolley?
1. Trolley structure
Both hydraulic and mechanical types are available. The hydraulic type has low rigidity requirements for the trolley frame, flexible structure type, light weight, low processing requirements and low elevation requirements for the track laying in the construction, and easy to use, but it has high requirements for the self-locking of the hydraulic cylinder, and the hydraulic cylinder in the lining is not allowed to retract . The mechanical type is the opposite. Because one motor must drive several lead screws, the coaxiality of each drive shaft is required to be high, and the trolley frame must have greater rigidity, and the structure and size must be accurate.
Due to the heavy structure and high processing requirements, And because the lead screw is synchronized action (unlike hydraulic transmission, each hydraulic cylinder can be synchronized or independently), when the track elevation error (each point is not at the same elevation) is large, it will directly affect the template position, thereby affecting the lining quality. After analysis and comparison, the hydraulic transmission scheme is selected, and measures such as hydraulic lock and balance valve are adopted for the hydraulic cylinder to make the hydraulic cylinder self-locking; at the same time, the screw mechanism is used for mechanical locking, and the support of the template is strengthened to ensure that the template does not return during lining. Shrink without deformation.
2. Frame structure
The trolley adopts hydraulic transmission, which simplifies the structure of the trolley frame and reduces the weight. At the same time, it also improves the flexibility and diversity of the structure. After the analysis and comparison of various trolley frame structure schemes, the strength calculation and optimization select 9m four-door frame 12m The main door frame structure scheme reduces the structural weight by more than 40% compared with the mechanical type, and reduces the production cost by more than 25%.
3. Steel mold structure
The steel mold is the working device of the trolley. Its appearance quality and dimensional accuracy directly determine the quality of the concrete lining. At the same time, it is the most difficult part to process. A reasonable processing and welding process has been formulated, and a special assembled welding tire mold has been designed and processed. In order to ensure the accuracy of the overall dimensions, minimize welding distortion, and ensure that the outer surface is smooth and free of defects such as unevenness. In order to control the misalignment of adjacent formwork, the stabilizing pin of interference fit is used to fix the connecting plate of adjacent formwork as a whole, which effectively controls the misalignment of adjacent formwork caused by the gap between bolt holes and ensures the quality of concrete lining .
4. Support structure
The entire mass of the lining concrete is transmitted to the supporting mechanism through the steel mold of the trolley, and then to the portal frame. The lining concrete is in a solid-liquid state, which produces large vertical pressure and lateral pressure on the top and side directions, and at the same time produces a large buoyancy. When the buoyancy exceeds the vertical pressure and the weight of the trolley, the trolley will float. Will not work properly. In order to solve this technical problem, after careful calculation, optimized design, and reasonable selection of each supporting position. That is, the lower longitudinal beams on the inner side of the mast are supported with the ground to avoid lateral pressure to cause the mast columns to retract, and there are several horizontal supports on the outer side of the mast and the longitudinal beams of the side form, at the upper beam and the upper longitudinal beam of the mast It adopts several vertical supports (the top hydraulic cylinders are arranged on the horizontal part of the gantry at both ends, and the middle is the vertical supporting screw), which is uniformly distributed in the longitudinal direction of the trolley.
The tunnel lining trolley is a special equipment that must be used in the secondary lining of the tunnel construction process, and is used for the concrete lining construction of the inner wall of the tunnel. The above is the specific description of the structural characteristics of the tunnel lining trolley. I hope it can help everyone to know more about the tunnel lining trolley.