Construction of turnout sleepers
1. Construction preparation
(1) Review the subgrade section size, flatness, and elevation, verify the penetration of the line center line, and nail the line center pile after confirming that it is qualified. Five control piles on the curve are nailed.
(2) According to the frame laying progress plan and the track laying plan, formulate the implementation construction organization design of laying the ballast bed.
(3) Determine the sand field for the supply of bottom ballast to ensure the smoothness of the construction access road. Implement the output of the surface ballast field, strictly control the quality of the ballast, including the ballast grade, material mechanical properties, gradation, particle shape and cleanliness standards, etc., conduct sampling tests according to the specifications, and confirm that it is qualified before use. Prepare a loading and transportation supply plan before use.
(4) Implement the labor, materials and equipment required for the construction, and check the integrity of the construction equipment and equipment.
2, lay the bottom ballast
(1) The construction of turnout sleepers shall be based on the line piles, release the side lines of the ballast on both sides according to the designed ballast width, and set up the ballast thickness control piles.
(2) The main line is designed as a double-layer track bed, and the bottom ballast is medium-coarse sand. The bottom ballast is transported directly to the site by the car for laying, and unloaded evenly according to the planned amount. Manual paving and wire-pull shaping and leveling, compaction by small rollers.
(3) In order to cooperate with the laying of beams and rails, all the bridge heads along the line should be pre-laid with 30cm thick ballast within 30 meters, so that the road bed surface is not less than 5cm above the abutment ballast retaining wall, and the slope should be 5‰. The smooth connection of the ballast surface.
3. Cooperate with the laying unit to lay the rail row. The laying unit (the 22nd tender) is responsible for laying the rail row. The main line and bridge of this tender section are laid continuously. During the laying of the track, we will cooperate with the track laying frame to carry out the whole track. The work content is: square sleepers, fastening accessories and fasteners, stringing the bottom ballast under the sleepers at the bearing rails, and eliminating overtaking and triangular pits. Ensure that the train speed reaches 15km/h after track laying, strengthen line maintenance, and ensure the safety of engineering trains.
4. Ballasting the road
(1) The ballast track on the main line of the construction of turnout sleepers is coordinated with the construction of the frame. After a section of the rail row is laid, the K-type trains are used to unload the ballast evenly along the section, and then the ballast track is carried out. The four processes of one-time ballasting and finishing, two-times ballasting and repairing, and line refurbishment form a streamlined operation.
(2) The ballasting is carried out in two times. The thickness of the ballast is 0.15-0.2 meters under the pillow. After the whole operation of the ballast, the speed of the engineering train can reach 25km/h. After passing through 5 engineering trains, the ballast can be filled for two times to make the whole road, so that the passing speed of engineering trains can reach 35km/h. The height difference of the temporary track bed at the sub-section construction site of the main line shall be connected with a slope of not more than 5‰.
(3) Sequence of ballast loading and finishing: every time ballast loading and finishing, part of the ballast in the pillow box should be supplemented first, then lift the track, square pillows, string the ballast, straighten the track direction, tamper the ballast bed, backfill and clean the ballast and stabilize it. line. The dimensions of each part of the track shall gradually meet the requirements of the acceptance specification after the line is refurbished after being ballasted twice.