Construction Process of Rack Beam
Preparation Before Construction
The drawings provided by the owner shall be reviewed before construction to determine the length, width, and weight of the slabs and the technical parameters such as the longitudinal slope, transverse slope, obliqueness, curvature, etc. of the bridge, and splice the bridge erecting machine according to the needs. All safety inspections and protections must be done well. It is strictly forbidden to carry out hoisting operations when there are severe winds of magnitude six or above or severe weather such as heavy rain, heavy snow, and heavy fog.
Erecting Machine in Place
Assemble strictly in accordance with the installation plan of the erecting machine, and do truss support to prevent tilting during assembly. The traverse track must be horizontal and parallel. The distance between the traverse track support points is not more than 100cm. Adjust the front and rear outriggers so that the longitudinal slope of the main beam of the bridge erector is less than 1.5%. The bridge erector in place should ensure that the front fulcrum is 20cm-80cm higher than the rear fulcrum. The non-working state bridge erecting machine should be parked in the middle of the bridge, install the rail clamps, plug the wooden wedges, and pull the hoist and the traverse rail to fix the front and rear brackets.
Beam Sheet Transportation
The lateral height difference of the transportation track laying should be less than 5cm, and the longitudinal smoothness. The length of the hollow part under the track should not be greater than 50cm. The distance between two flat cars should meet the distance requirements of the support points, and the fulcrum should be a movable turntable. Tensioning tools such as gourd are used to effectively fix the beam piece and the movable turntable as a whole.
Beam Feeding
When feeding beams, the beam trolley must move at a low speed, which is consistent with the vertical speed of the crane. Suspension beams, moving beams: The lifting beams of the front crane should not be too high, and it is advisable to pass the bridge support of the bridge crane. After the beams are lifted by the front and rear cranes, the beam-carriage flatcar exits the bridge crane and transports the next beam. After the beam piece is moved vertically, it should be lowered to a position about 30cm away from the covered beam pier, and then the bridge crane is moved laterally.To ensure safety, the side beams should not be erected behind the secondary side beams.
Beam Sheet Adjustment and Positioning
Use the vertical and horizontal movement of the crane and hoist to fine-tune the position of the beam sheet. After the beam piece is seated, it should be supported by square wood in time, and the wedge should be plugged under the square wood. Only after the beam pieces are supported, can the crane wire rope be loosened. After the beam piece is in place, the bridge erecting machine should return to the beam feeding position immediately.
Report to a professional quality inspector or professional engineer for inspection: According to the design requirements, enter the erection of the lower beam after passing the inspection. After the erection of the cross-beam sheet is completed in this way, the bridge erecting machine performs a hole.
Bridge Machine Vias
If the erected beams are not welded properly, it is strictly forbidden for bridge machines to carry out vias. A special person should be equipped to observe and monitor the situation of the front and rear supports and the running wheels to prevent accidents such as bite roads and derailments. After passing through the hole, the traverse track behind the bridge erecting machine should not be in the middle of the erected beams, and should be placed as far as possible at the end of the beam with a transverse partition.
