Key points for making tunnel lining formwork trolley

(1) The secondary lining construction (including the widening section) should adopt the whole lining trolley with full hydraulic automatic walking. The lining trolley should have accurate structural dimensions, and all kinds of telescopic components, hydraulic system and electrical control system should run well. Supporting mechanism; should meet the requirements of automatic walking, and have a locking device to ensure accurate positioning.

(2) The two-lined trolley must enter the tunnel forward field. There must be two two-lined trolleys at the end of the arch tunnel and the small clearance tunnel to ensure the reasonable distance between the left and right lines and the second lining. Structural safety.

For the section of the widened section at the IV and V surrounding rock, the widened section integral lining trolley shall be specially equipped to ensure the timely application of the widened section.

(3) The overall template plate of the trolley consists of a panel, a supporting skeleton, an articulated joint, a working window, etc. When the lining section is large and the load is large, the supporting skeleton should be made into a truss structure, and the number of slab joints should be reduced as much as possible. . The formwork and brackets shall have sufficient strength, rigidity, stability and resistance to floating, and shall be able to withstand the gravity, side pressure and various loads that may occur during construction. The template does not have irregularities, the bracket is not offset, and is not twisted, and is not deformed for repeated use. The trolley design should be easy to move and accurately seated.

(4) The clearance of the trolley formwork supporting the truss door should meet the requirements for the passage of large equipment required for the construction of the tunnel lining; the height of each platform of the truss should meet the construction requirements, which is conducive to the construction work of the workers, such as safety management and tamping. There are climbs up and down. See Figure 8.3.1-2. (5) In order to ensure the lining clearance, the outer diameter of the template should be appropriately expanded considering the amount of deformation as a reserved settlement. (6) The thickness of the steel plate of the two-lane two-liner deck shall be not less than 10mm; the thickness of the two-lane tunnel two-liner deck shall be not less than 12mm; the four-lane two-liner shall be calculated and invited to be reviewed by experts. . In order to reduce the trace between the two liners, the width of each steel plate of the outer arc template is recommended to be 2m, but should not be less than 1.5m. The indirect seam of the plate is lapped or welded by the tooth gap. In order to ensure that the two-line trolley has a certain rigidity and strength, it is recommended that the weight of each two-lane trolley should not be less than 6.8 tons per meter, and the weight of each three-lane trolley should not be less than 8.5 tons. (8) The working window shall be set at 3m, 5.3m and the vault. The longitudinal distance of the working window shall not be more than 3m, the lateral direction shall not be greater than 2.5m, the window size shall be 50cm×50cm, and shall be uniform and uniform; the perimeter of the working window shall be strengthened to prevent the surrounding Deformation, the window door should be flat, tight, and not leaking. As shown in Figure 8.3.1-3.

(8) The length of the two-lined trolley should be reasonably selected according to the plane curve radius and longitudinal slope of the tunnel. The length is generally 10~12m, and the length of the trolley with a curve radius less than 1200m should not exceed 9m. (9) The lining trolley shall be manufactured by the factory and assembled on site. The line, section and clearance size shall be inspected on site; the surface of the stencil shall be thoroughly polished before lining to remove rust spots and oil rust; Weld the joint and smooth the weld to suppress the warping deformation of the template during use, which affects the surface quality of the concrete and avoids the misalignment at the joint between the plates. (10) For the two-lined trolley that has been used. Strictly debug the operation of various telescopic components, hydraulic systems, and electrical control systems to ensure good use, otherwise they should be replaced. A new outer arc template must be replaced and qualified by a professional formwork manufacturer.