Monolithic ballast bed combined lifting construction method

Abstract

The monolithic track bed combined lifting construction method comprises the following steps that 1, the lifting amount is determined, the line geometric dimension of a monolithic track bed lifting section is collected, the difference value between an existing track surface line type and a target line type is determined, and the lifting amount of each fastener of the lifting section is determined according to the difference value; 2, grouting hole marking and drilling are conducted, specifically, the positions of grouting holes are marked, drilling is conducted according to the marked hole positions, and drilling is finished after the drilling depth meets the requirement; 3, grouting pipes are installed, the grouting pipes are inserted into the grouting holes, and the grouting pipes and the grouting holes are fixed; 4, grouting and lifting are conducted, specifically, a lifting grouting material is injected from a grouting pipe, the elevation of the tracks on the left side and the right side of the track plate is monitored through an electronic level gauge, center line deviation is monitored through a total station, and grouting is stopped after the preset lifting amount is reached; and 5, the grouting holes are blocked and filled, and lifting is completed. According to the monolithic track bed combined lifting construction method, accurate grouting and lifting can be achieved, and the grouting effect is ensured.

Description

Technical Field

[0001] This invention relates to a method for raising railway tracks, specifically a method for raising integral track bed assembly. Background Technology

[0002] A monolithic track bed is a track bed constructed entirely of cast concrete. Wooden sleepers, concrete sleepers, or short concrete sleepers can be pre-embedded within the track bed. Fasteners, elastic pads, and rails can also be directly installed on the monolithic concrete track bed, hence the name "monolithic track." However, due to excessive foundation settlement, the monolithic track bed needs to be raised as a whole. The existing method involves digging pits under the rails, then using jacks to raise the rails, and finally injecting polymer grout for overall raising. Repeated drilling and injection of polymer material to raise the track bed slab to the required height is possible, but this method cannot achieve precise grouting and post-construction supervision. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problem that the precision of grouting and lifting cannot be controlled in the existing technology, and to provide an integral track bed combination lifting method that can achieve precise grouting and lifting and ensure the grouting effect.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The integral track bed assembly lifting method is unique in that it includes the following steps: Step 1, Determine the lifting amount The track geometry of the overall track bed lifting section is collected to determine the difference between the current track surface alignment and the target alignment. Based on the difference, the lifting amount at each fastener in the lifting section is determined. Step 2, Grouting hole marking and drilling Mark the location of the grouting holes, and drill according to the marked hole positions. Drilling is completed when the drilling depth meets the requirements. Step 3, Install grouting pipe Insert the grouting pipe into the grouting hole and fix the grouting pipe to the grouting hole; Step 4, Grouting and Lifting The lifting grouting material is injected into the grouting pipe, and the elevation of the track on both sides of the track slab is monitored by an electronic level. At the same time, the centerline offset is monitored by a total station. Grouting is stopped after the predetermined lifting amount is reached. Step 5: Seal and fill the grouting holes to complete the lifting process.

[0005] Furthermore, the specific steps of step 2 are as follows: Step 2.1: Divide the lifting section into multiple lifting units, and mark the middle hole and the two side holes in the middle and on both sides of each lifting unit, respectively. The middle hole and the two side holes are located on the same horizontal line. Step 2.2: Drill holes according to the marked hole positions. The middle hole is drilled vertically from the surface of the track slab or track bed slab, and the two side holes are drilled at a 45° angle to the horizontal plane. Step 2.3: Drilling ends when the drilling depth penetrates the support layer, base plate, or leveling layer and reaches the surface of the subgrade.

[0006] Furthermore, the specific steps of step 4 are as follows: Step 4.1: Plan the predetermined grouting sequence for the lifting unit; Step 4.2: Perform grouting according to the predetermined grouting sequence; During grouting and lifting, the elevation of the track on both sides of the track slab is monitored synchronously using an electronic level. Step 4.3: Repeat step 4.2 to perform multiple grouting and lifting operations until the predetermined lifting amount is reached, then stop grouting.

[0007] Furthermore, in step 2.1, the multiple lifting units of the lifting section are in units of 5m, and the lateral and longitudinal spacing between the two holes on both sides of each lifting unit is 1.25m.

[0008] Furthermore, in step 2.2, the drilling angle deviation is ±5° and the drilling diameter is 12mm.

[0009] Furthermore, in step 3, the grouting pipe is closed at a height lower than the upper surface of the base plate and exposed at a height greater than 10cm, and the grouting pipe is fixed by a nut at the grouting pipe opening.

[0010] Furthermore, in step 4.2, during grouting and lifting, two precision electronic levels are used to monitor the elevation of the track on both sides of the track slab, keeping the horizontal change of the track structure within ±2mm. The grouting material is a two-component polymer polyurethane material.

[0011] Furthermore, in step 4.3, during multiple grouting and lifting operations, the maximum lifting amount per operation is less than 10 mm.

[0012] Furthermore, in step 5, the grouting holes are sealed and filled with C50 epoxy mortar.

[0013] Furthermore, step 5 is followed by step 6, in which a track inspection trolley is used to perform a fine measurement of the track in the raised section. Based on the trolley data, the track in the raised section is finely adjusted so that the geometric dimensions meet the track geometric dimension operation acceptance standard of 80 km / h < υmax ≤ 120 km / h.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects: 1. The integral track bed combination lifting method of the present invention, through combined construction and radar scanning in the middle, can achieve precise grouting and lifting, and ensure the grouting effect.

[0015] 2. In the integral track bed assembly lifting method of the present invention, foamed polymer quick-setting material is injected into each grouting hole. After the track bed slab and the track slab are lifted together to the corresponding elevation, C50 epoxy mortar is used to seal and fill the grouting holes to ensure that the grouting holes do not become weak points for future rainwater erosion and that no leakage occurs.

[0016] 3. In the integral track bed combination lifting method of the present invention, the lifting of each section starts from the point of maximum settlement and is carried out step by step, with each lifting amount not exceeding 10mm; at the same time, the length of each lifting should be reasonably planned in conjunction with the railway's given construction time to avoid delays. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the integral track bed assembly lifting method of the present invention; Figure 2 This is a schematic diagram of the grouting hole arrangement for the integral track bed combination lifting method of the present invention; Figure 3 This is a schematic diagram of the grouting and lifting drilling process for the integral track bed combination lifting method of the present invention; Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] The integral track bed lifting method of this invention employs a three-step control approach for grouting lifting quality control: "formulating a lifting plan—real-time monitoring during the process—re-measurement of the track alignment after lifting." Step 1: Before grouting lifting, a plan is formulated based on the track alignment and the geometric requirements for train speed limits, including the lifting range, lifting point layout, and lifting height. A lifting control table is created for on-site implementation. Step 2: During grouting lifting, the lifting points are arranged strictly according to the control table. During the grouting lifting process, an electronic level is used to monitor the elevation of the left and right rails at the lifting points and the midpoint between two lifting points in real time, thereby calculating the lifting amount. Grouting stops when the actual lifting amount reaches the planned amount in the control table. Step 3: After all the ballastless track in the planned lifting section has been lifted, the track elevation is checked sleeper by sleeper to confirm whether the expected lifting effect has been achieved and whether the track geometry meets the conditions for train operation. Lifting points that do not meet the requirements should be lifted again to ensure their elevation meets the alignment requirements.

[0020] For the subsided sections, drill injection holes with a diameter of 25mm and a depth of 350mm or 900mm on the center and both sides of the track. Repeat drilling and injection of polymer material to raise the track bed slab to the required height (each raising height not exceeding 10mm). The track elevation is raised to the design position using polymer grouting technology. The main processes include drilling, grouting, and sealing. Nine grouting holes are drilled in each slab. Foamed, fast-setting polymer material is injected into the holes, and the track bed slab, along with the track slab, is raised to the corresponding elevation. Then, C50 epoxy mortar is used to seal and fill the grouting holes to ensure they do not become weak points for future rainwater erosion and to prevent leakage. Construction proceeds first at the settlement area below the loading silo, then at the locomotive maintenance line, and finally at the entire station track bed. The lifting of each section should begin from the point of maximum settlement and proceed step by step, with each lifting increment not exceeding 10mm. At the same time, the length of each lifting operation should be planned reasonably in accordance with the railway's designated construction schedule to avoid delays.

[0021] For settlement of the ballastless track structure, a polymer grouting and lifting scheme was adopted for treatment to restore the track's elevation smoothness. During on-site implementation, the fasteners in the lifting section were replaced with standard fasteners. With the standard fasteners in place, the track was lifted to the design position. The construction process is as follows: Figure 1 As shown.

[0022] (1) Determine the lifting amount Before construction, the on-site settlement data was verified, the precision measurement network was checked, and the geometric dimensions of the track were collected using a precision adjustment trolley to determine the difference between the current track surface alignment and the target alignment. The usage of the height adjustment pads at each fastener in the raised section was investigated to determine the lifting amount at each fastener in the raised section.

[0023] (2) Investigation and protection of existing equipment Before construction, survey the trackside facilities in the construction section, protect electrical equipment, power and signal cables that may affect the lifting and correction work, and cooperate with electrical personnel to develop a protection plan. Before drilling, avoid and protect electrical equipment and signal cables with dust cloths, loosen the fixing clamps of the cross-rail pipelines, and restore them after construction.

[0024] (3) Grouting hole marking and drilling Oil-based markers are used to mark the grouting hole locations. The Z-dot represents the grouting lift hole. Each lift unit is 5m long. Within a lift unit, the longitudinal spacing between two holes is 1.25m (along the track direction), and the transverse spacing is 1.25m (perpendicular to the track direction). When laying out the lines, the centerline of the track is used as a reference, and the transverse drilling positions are offset 1.25m to either side of the track. For longitudinal laying, the center of the expansion joint is used as a reference, and the first row of longitudinal drilling positions is offset 0.625m along the track direction. The spacing between two holes is 1.25m. The intersection of the longitudinal and transverse lines is the drilling point. Figure 2 As shown.

[0025] like Figure 3 As shown, drill holes according to the marked positions using an electric hammer drill. The central hole should be drilled vertically into the surface of the track slab or ballast slab, while the side holes should be drilled at a 45° angle to the horizontal plane. The drilling angle deviation should be controlled within ±5°. The hole diameter is 12mm, and the drilling depth should be sufficient to penetrate the supporting layer, base plate, or leveling layer to reach the surface of the subgrade. The drilling position on the top surface of the base plate or leveling layer should be 250mm from the edge. Avoid drilling reinforcement and transponders. After drilling, promptly clean and collect the drilled dust and debris to prevent environmental pollution. Temporarily seal the grouting holes with silicone sealant to prevent rainwater and debris intrusion. When arranging grouting holes on site, adjustments can be made if transponders, cables, or other facilities are encountered.

[0026] When drilling grouting holes, the design depth and angle must be strictly followed. To prevent deviation in the grouting hole angle, an angle locator is used on-site to assist drilling. Drilling powder should be cleaned and collected promptly to avoid contaminating the track slab. After drilling is completed, the grouting holes should be sealed with silicone sealant or a special sealing material to prevent rainwater and impurities from entering.

[0027] To accurately determine the location of the grouting and lifting points, the sleepers on site should be numbered before grouting and lifting the ballastless track, and then the lifting point locations should be marked according to the design drawings. When marking, a measuring tape or steel ruler should be used to accurately measure the points to ensure that the positional deviation is within the standard range.

[0028] (4) Install grouting pipe First, clean the material that temporarily seals the grouting hole. Then, insert the special grouting pipe into the grouting hole. Insert the grouting pipe to the bottom of the hole, and the sealing height of the grouting pipe should be lower than the upper surface of the base plate. The exposed height should be greater than 10cm (for connecting the grouting gun). Tighten the pipe end nut with a wrench to fix the grouting pipe.

[0029] (5) Restore standard fasteners Determine the range of parking gap increase for the day, and consider the connection with adjacent lines. Remove the height adjustment fasteners and pads, and restore the standard fasteners.

[0030] (6) Grouting and lifting 1) Before grouting operations, the grouting equipment should be debugged in advance to ensure normal operation, and the initiation and surface drying times of the grouting material should be tested to confirm that they meet the requirements; at the same time, the grouting lift at each point should be verified on site. The grouting material used for lifting should be a two-component high-polymer polyurethane material, and its technical indicators must meet the design requirements.

[0031] 2) First, inject two-component high-polymer polyurethane material into the low-lying area. During the grouting and lifting process, use two precision electronic levels to monitor the track elevation on both sides of the track slab. The horizontal change of the track structure should be controlled within ±2mm. Use a total station to monitor the centerline offset. The track structure should not have obvious lateral displacement.

[0032] 3) Grouting shall be carried out in accordance with the predetermined grouting unit and grouting sequence. The maximum lifting amount in a single operation shall not exceed 10 mm. Grouting operation shall be stopped after the predetermined lifting amount is reached.

[0033] 4) During grouting, two precision electronic levels are used to monitor the elevation of the track on both the left and right sides corresponding to the filling point. Grouting is stopped immediately if any change in track elevation is detected. If necessary, radar scanning is used to ensure the grouting effect.

[0034] 5) During grouting and lifting, the track surface alignment should be monitored in real time and should not exceed the target alignment. During the grouting process, a designated person should observe the track structure around the grouting point. If cracks, bulges, or grout leakage are found in the track structure, grouting should be stopped immediately.

[0035] When drilling grouting holes, the design depth and angle must be strictly followed. To prevent deviation in the grouting hole angle, an angle locator is used on-site to assist drilling. Drilling powder should be cleaned and collected promptly to avoid contaminating the track slab. After drilling is completed, the grouting holes should be sealed with silicone sealant or a special sealing material to prevent rainwater and impurities from entering.

[0036] 6) After the grouting and lifting construction is completed during each daily parking gap, the geometric dimensions of the line shall be checked and the geometric dimensions of the line shall meet the conditions for line opening.

[0037] (7) Grouting hole plugging and sealing layer repair The grouting holes were sealed and filled with C50 epoxy mortar to ensure that they would not become weak points for future water erosion and to prevent leakage.

[0038] (8) Track fine-tuning After grouting and lifting are completed, a track inspection trolley is used to conduct precise measurements of the track. Based on the trolley data, a fine-tuning plan is developed, and the track is finely adjusted to ensure that the geometric dimensions meet the track geometric dimension operation acceptance standards for speeds of 80 km / h < υmax ≤ 120 km / h.

Claims

1. The integral track bed assembly lifting method, characterized by: Includes the following steps: Step 1, Determine the lifting amount The track geometry of the overall track bed lifting section is collected to determine the difference between the current track surface alignment and the target alignment. Based on the difference, the lifting amount at each fastener in the lifting section is determined. Step 2, Grouting hole marking and drilling Mark the location of the grouting holes, and drill according to the marked hole positions. Drilling is completed when the drilling depth meets the requirements. Step 3, Install grouting pipe Insert the grouting pipe into the grouting hole and fix the grouting pipe to the grouting hole; Step 4, Grouting and Lifting The lifting grouting material is injected into the grouting pipe, and the elevation of the track on both sides of the track slab is monitored by an electronic level. At the same time, the centerline offset is monitored by a total station. Grouting is stopped after the predetermined lifting amount is reached. Step 5: Seal and fill the grouting holes to complete the lifting process.

2. The integral track bed assembly lifting method according to claim 1, characterized in that, The specific steps of step 2 are as follows: Step 2.1: Divide the lifting section into multiple lifting units, and mark the middle hole and the two side holes in the middle and on both sides of each lifting unit, respectively. The middle hole and the two side holes are located on the same horizontal line. Step 2.2: Drill holes according to the marked hole positions. The middle hole is drilled vertically from the surface of the track slab or track bed slab, and the two side holes are drilled at a 45° angle to the horizontal plane. Step 2.3: Drilling ends when the drilling depth penetrates the support layer, base plate, or leveling layer and reaches the surface of the subgrade.

3. The integral track bed assembly lifting method according to claim 1, characterized in that, The specific steps of step 4 are as follows: Step 4.1: Plan the predetermined grouting sequence for the lifting unit; Step 4.2: Perform grouting according to the predetermined grouting sequence; During grouting and lifting, the elevation of the track on both sides of the track slab is monitored synchronously using an electronic level. Step 4.3: Repeat step 4.2 to perform multiple grouting and lifting operations until the predetermined lifting amount is reached, then stop grouting.

4. The integral track bed assembly lifting method according to claim 2, characterized in that: In step 2.1, the multiple lifting units of the lifting section are in units of 5m, and the horizontal and vertical spacing between the two holes on both sides of each lifting unit is 1.25m.

5. The integral track bed assembly lifting method according to claim 2, characterized in that: In step 2.2, the drilling angle deviation is ±5° and the drilling diameter is 12mm.

6. The integral track bed assembly lifting method according to claim 1, characterized in that: In step 3, the grouting pipe is closed at a height lower than the upper surface of the base plate and exposed at a height greater than 10cm. The grouting pipe is fixed by a nut at the pipe opening.

7. The integral track bed assembly lifting method according to claim 3, characterized in that: In step 4.2, during grouting and lifting, two precision electronic levels are used to monitor the elevation of the track on both sides of the track slab, keeping the horizontal change of the track structure within ±2mm. The grouting material is a two-component polymer polyurethane material.

8. The integral track bed assembly lifting method according to claim 3, characterized in that: In step 4.3, during multiple grouting and lifting operations, the maximum lifting amount per operation is less than 10 mm.

9. The integral track bed assembly lifting method according to any one of claims 1-8, characterized in that: In step 1, the overall track bed lifting section includes the loading silo section, the locomotive maintenance line, and the station's overall track bed; during construction, the settlement area below the loading silo is constructed first, then the locomotive maintenance line is constructed, and finally the station's overall track bed is constructed. In step 5, the grouting holes are sealed and filled with C50 epoxy mortar; Step 4 also includes scanning the grouting process with radar to ensure that the grouting material is completely filled.

10. The integral track bed assembly lifting method according to claim 9, characterized in that: Step 5 is followed by step 6, which involves using a track inspection trolley to perform precise measurements on the track in the raised section. Based on the trolley data, the track in the raised section is finely adjusted so that the geometric dimensions meet the track geometric dimension operation acceptance standard of 80 km / h < υmax ≤ 120 km / h.

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