Rail transit depot prefabricated column type maintenance pit top-down construction method

Abstract

The application discloses a rail transit depot prefabricated column type maintenance pit top-down construction method, which comprises the following steps: firstly, construction preparation and base treatment are performed, a track arrangement drawing is drawn, base marks are measured and set, track materials are scattered, track erection and fastener installation are performed, after initial adjustment of the track, prefabricated column transportation and installation are performed, after the prefabricated column installation is completed, steel bar binding and formwork installation are performed, then, final adjustment of the track and the prefabricated column is performed, finally, base concrete pouring and maintenance are performed, and finally, the construction is completed. The application adopts the top-down construction method, simultaneously uses a track support device as an auxiliary, can realize accurate and rapid adjustment of the prefabricated column and the track, and improves construction efficiency and construction quality.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of rail transit, and particularly relates to a prefabricated column type maintenance pit reverse construction method for a rail transit depot. BACKGROUND

[0002] The construction of a column type maintenance pit bed in a depot has many problems, such as narrow construction space, intensive cross operation, limited use of large mechanical equipment, large number of heavy rail materials, and difficult transportation channel. The traditional prefabricated column construction method needs to install and level the prefabricated column first, then install the track fastener, control the track elevation by controlling the column elevation, which is extremely difficult and easy to cause the track to rise and fall, and is difficult to handle in the later period. At the same time, the prefabricated column foundation has a very high flatness requirement, and the positioning and leveling of the prefabricated column are difficult, and the steel bars under the column cannot be pre-buried and need to be handled later. Therefore, the prefabricated column construction by the forward method has high difficulty, low construction efficiency, poor construction quality, and is difficult to be popularized and applied in subway construction. SUMMARY

[0003] The present application aims to overcome the deficiencies in the prior art, and provides a prefabricated column type maintenance pit reverse construction method for a rail transit depot, which uses reverse construction method and uses track support device as auxiliary, can realize accurate and rapid adjustment of prefabricated column and track, and improve construction efficiency and construction quality.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is to provide a prefabricated column type maintenance pit reverse construction method for a rail transit depot, comprising the following steps:

[0005] Step one, construction preparation and base treatment, draw the track arrangement diagram, determine the number and detailed position of the rails and prefabricated columns in the depot;

[0006] Step two, measuring and setting base marks: using control base mark method to measure and set encrypted base marks by total station;

[0007] Step three, scattering rail materials and installing tracks and fasteners: transporting the rail materials and track support devices to the corresponding positions respectively, hoisting the rails to the designed elevation position by the portal support combined with the L ruler, installing the track support device under the rails for supporting the rails, and installing the fasteners on the rails according to the position of the prefabricated column in step one;

[0008] Step four, track initial adjustment: adjusting the geometric state of the track according to the design and specification requirements by the L ruler combined with the track support device according to the edge stake and elevation data of the measured base mark;

[0009] Step five, prefabricated column transportation and installation: transporting the prefabricated column by the truck-mounted crane, hoisting the prefabricated column to the bottom of the fastener in step three, and connecting the prefabricated column and the fastener by bolt spikes to complete the installation of the prefabricated column;

[0010] Step six, steel reinforcement and formwork installation: after all the precast columns are installed, the anchoring steel reinforcement in the pit is checked to be screwed into the steel reinforcement connector embedded in the bottom of the precast column. After passing the inspection, the concrete pouring formwork is installed at the bottom of the precast column, and the formwork is ensured to be tight and not to leak grout;

[0011] Step seven, track and precast column final adjustment: according to the real-time measurement data of L size and track detector, the track geometry size and the verticality of the precast column are adjusted by the track support device, and the acceptance is qualified.

[0012] Step eight, foundation concrete pouring and curing: the concrete is poured and the foundation concrete is watered and cured after the concrete pouring is completed. When the strength of the foundation concrete reaches 75% of the design value, the track support device can be removed. When the strength of the foundation concrete reaches 100% of the design value, the construction of the precast column pit bed is completed.

[0013] Further, the construction preparation and base treatment in step one include the following steps:

[0014] S1, carry out site investigation, check the number and position of base embedded parts, the height of reserved steel reinforcement and the width of foundation, and accept the quality of precast columns entering the site;

[0015] S2, organize mechanical equipment to enter the site, and install the portal support on the track to be constructed;

[0016] S3, according to the measurement data of the construction limit of the site, customize the truck-mounted crane for precast column transportation and installation, the body width of the truck-mounted crane can be constructed in the construction area, and the rotating angle of the hook of the truck-mounted crane is not less than 180°.

[0017] Further, the track support device comprises: a transverse support member, the transverse support member comprises a middle cross bar and side cross bars arranged on both sides of the middle cross bar, the middle cross bar and the side cross bars are connected through a support plate, a steel rail is arranged on the support plate, and a transverse bolt is arranged at one end of the middle cross bar close to the support plate and one end of the side cross bar close to the support plate; a longitudinal support member, the longitudinal support member comprises two lead screws, the top ends of the two lead screws are respectively vertically threaded through the side cross bars on both sides of the middle cross bar, the bottom ends of the two lead screws are respectively perpendicular to the ground on both sides of the pit, and the two lead screws are used to adjust the height of the steel rail.

[0018] Further, the track support device further comprises a track direction adjusting member, the track direction adjusting member comprises two cross arranged inclined struts, both of the inclined struts are screw telescopic rods, the top of both of the inclined struts is respectively provided with a top support, the top support is U-shaped, the top support is clamped with the rail bottom surface of the steel rail and the track direction can be adjusted by rotating the top support, the bottom end of both of the inclined struts is arranged in the column inspection pit through an anchor nail.

[0019] Further, a wedge-shaped pad for adjusting the rail bottom slope is arranged between the steel rail and the support plate.

[0020] Further, the number of the track support devices is multiple groups, and the interval between the multiple groups of track support devices is 2.5 m.

[0021] Further, the interval between the base marks in step two is 5 m, and the positioning accuracy is ±2 mm.

[0022] Further, after the initial adjustment of the track in step four, the allowable deviation of the track levelness is ±10 mm, and the allowable deviation of the track gauge is +3 mm to -2 mm.

[0023] Further, after the final adjustment of the track and the column in step seven, the allowable deviation of the track gauge is +2 mm to -1 mm, the allowable deviation of the track levelness is ±2 mm, the track direction error is not greater than 2 mm, the high-low error is not greater than 2 mm, the allowable deviation of the column perpendicularity is ±1°, the rail bottom slope is set according to 1 / 35 to 1 / 45, the allowable deviation of the track center line is 5 mm, and the allowable deviation of the elevation is ±2 mm.

[0024] Further, the steel rail joint is arranged in the middle between the two prefabricated columns.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] 1. The present application adopts the top-down method of erecting the rail first and then suspending the prefabricated column, the track support device is used to adjust the track to the error range according to the design requirements, and then the prefabricated column is installed, so that the prefabricated column and the track can be accurately and quickly adjusted, the problem of difficult construction in the top-down method is solved, the problems of narrow construction space and multiple cross construction are solved, and the construction quality and construction efficiency are improved.

[0027] 2. The present application adopts the track support device, which has high support strength and high steel degree, good overall stability, can bear the load of the track and the prefabricated column, small track deformation, and can realize dynamic millimeter-level adjustment of the track geometric size through the transverse support member and the longitudinal support member, the wedge-shaped pad is arranged between the rail bottom of the steel rail and the support plate, the 1 / 40 rail bottom slope is realized, and the construction precision and construction efficiency are improved.

[0028] 3. This invention uses a customized truck-mounted crane, which can quickly lift, transport horizontally, and suspend precast columns, solving problems such as the difficulty of transporting and installing precast columns in confined working spaces, reducing damage during the transportation process, and greatly improving the efficiency and accuracy of precast column transportation and installation.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the construction process of the present invention.

[0031] Figure 2 This is a schematic diagram of the structure during track laying according to the present invention.

[0032] Figure 3 This is a schematic diagram showing the cooperation between the track support device and the track of the present invention.

[0033] Figure 4 This is a schematic diagram showing the cooperation between the track direction adjustment component and the track in the track support device of the present invention.

[0034] Figure 5 This is the track layout diagram for the present invention.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1 - track support device; 11 - intermediate crossbar; 12 - side crossbar; 13 - screw rod; 14 - inclined strut; 15 - anchoring nail; 16 - wedge-shaped pad; 17 - top support; 18 - transverse bolt; 19 - support plate; 2 - prefabricated column; 3 - truck-mounted crane; 4 - portal frame; 5 - L ruler; 6 - steel rail; 7 - encrypted base mark. Detailed Implementation

[0037] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the invention. It should be understood that the accompanying drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] like Figures 1-5 As shown, a reverse construction method for precast column-type maintenance pits in rail transit vehicle depots includes the following steps:

[0040] Step one, construction preparation and base treatment, draw the track layout, determine the number and detailed location of the in-warehouse steel rails 6 and precast columns 2, and pay attention to the steel rail joints when laying the track, which should avoid the precast columns 2 and be centrally arranged between two precast columns 2, and the distance between the end precast column 2 and the rail end and the distance between each precast column 2 should be marked in the track layout, and the spacing between each precast column 2 is 1250mm.

[0041] Step two, measuring and setting base marks: using the control base mark method to measure and set the encrypted base marks 7 with a total station, that is, after construction preparation, the control base marks are measured and set through the control points handed over by the third party, and then the encrypted base marks 7 are measured and set according to the control base marks, the encrypted base marks 7 are used for track construction control, and the control points are re-measured before the layout of the encrypted base marks 7, after the re-measured data meet the specification requirements, the encrypted base marks 7 are measured and set, since the in-warehouse column-type monolithic track bed is a straight line, the setting interval of the encrypted base marks 7 is set to 5m, and the accuracy is controlled within ±2mm, the base mark material is customized, and after the base marks are set, regular re-measurement is carried out to strengthen protection, so as to avoid construction errors;

[0042] Step three, spreading track material and installing track and fasteners: using a crane to hoist the steel rails 6 from the warehouse door to the front of the warehouse, and then using a forklift to cooperate with the portal support 4 to transport the track material to the corresponding position according to the track layout, since the channel between the tracks is narrow, a narrow-body truck-mounted crane 3 is needed to cooperate to transport the track material and the track support device 1 to the corresponding position. Since the professional technicians have laid the track according to the length of the line, professional measurement personnel are arranged to further accurately position the steel rail joint position before track laying, for the convenience of construction, the track laying sequence can be from the front of the warehouse to the back of the warehouse, the track laying position must be accurate, the steel rails 6 are hoisted to the designed elevation position through the portal support 4 cooperating with the L ruler 5, the track support device 1 is installed below the steel rails 6 for supporting and reinforcing the steel rails 6, the setting interval of the track support device 1 is 1 set per 2.5m, and the installation position of the track support device 1 should avoid overlapping with the precast columns 2, after the steel rails are lifted to the designed elevation and direction ±10mm, the DJK5-1 type fasteners are installed on the steel rails 6 according to the precast column 2 position in the track layout of step one, the B type elastic strip is used at the joint, and the A type elastic strip is used at the remaining positions;

[0043] Step four, track initial adjustment: during the erection of the steel rail 6, the L ruler 5 cooperates with the track support device 1 to adjust the geometric state of the track according to the measurement encryption base mark and elevation data, and the detailed adjustment is carried out according to the design and specification requirements. Since the encryption base mark 7 is located at the midpoint of the track, and one encryption base mark 7 is arranged every 5 m, the transverse and vertical distances of the steel rail 6 from the encryption base mark 7 can be viewed through the L ruler 5. According to the comparison with the designed distance, the track support device 1 is used for adjustment. The L ruler 5 is commonly used in railways, and the horizontal and vertical rods are both marked with scales. The horizontal bubble is arranged on the horizontal rod, and the track elevation and the track transverse position can be measured at the same time. The specific method is as follows: first, adjust the track levelness, and then adjust the track gauge; first, adjust the place where the encryption base mark 7 is arranged, and then adjust the place between the encryption base marks 7 through the chord line and other methods; first, roughly, and then carefully. In order to save construction time, the track levelness is allowed to deviate ±10 mm during the initial adjustment of the track, and the track gauge is allowed to deviate +3 mm to -2 mm, so that the next process can be entered;

[0044] Step five, transportation and installation of prefabricated column 2: the prefabricated column 2 is transported by the truck-mounted crane 3, hoisted to the bottom of the fastener in step three, and connected with the fastener by bolt dowel, so as to complete the installation of the prefabricated column 2. In the process of transportation and installation, the BIM modeling technology is used to simulate the construction site in advance, and according to the characteristics of the prefabricated column 2, such as large single volume, heavy weight, difficult installation, and conflict between hoisting steel wire rope and steel rail, the prefabricated column installation support is used to hoist and install the prefabricated column 2, so as to improve the installation efficiency and accuracy. When the prefabricated column 2 is installed, the dowel oiler is used to oil the connecting bolt of the steel rail and the prefabricated column 2, so that the oiling is uniform and efficient;

[0045] Step six, steel bar binding and formwork installation: after all the prefabricated columns 2 are installed, the anchoring steel bars in the inspection pit are screwed into the steel bar connectors embedded in the bottom of the prefabricated column 2. After being tightened, the torque wrench is used for inspection. Only when the inspection is qualified, the next process can be carried out. After the steel bar binding is completed, the concrete pouring formwork is installed at the bottom of the prefabricated column 2. Specifically, the wooden formwork is used for form closing, the steel bars are planted outside the formwork outside the track for supporting the formwork, the square timber is used for transverse support between the formwork inside the track, and the long strip reinforcing formwork is arranged along the extension direction of the formwork inside and outside the track. The reinforcing formwork is used to ensure that the formwork is not deformed and is firmly reinforced, so as to ensure that the formwork is tight and does not leak mortar;

[0046] Step seven, track and prefabricated column final adjustment: after the column bottom anchoring steel bar and the formwork are accepted, the track support device 1 is used to adjust the track geometric size and the verticality of the prefabricated column 2 according to the real-time measurement data of the L ruler 5 and the track detector, so as to ensure that the track and the prefabricated column 2 have the accuracy within the error range of table 1. After the final adjustment is completed, the track is accepted. Only when the acceptance is qualified, the next process can be entered;

[0047] Table 1 Allowable deviation after track and column final adjustment

[0048] Detection items Error control after fine adjustment Measuring tool Track gauge +2mm~ -1mm Track gauge ruler Levelness ±2mm L ruler Track orientation ≯2mm 10m chord Height difference ≯2mm 10m chord Column perpendicularity ±1° Track detector Track bottom slope 1 / 35～1 / 45 Track detector Track centerline 5mm L ruler Elevation ±2mm L ruler

[0049] Step eight, foundation concrete pouring and curing: when pouring concrete, the vibration of the concrete should be strengthened, and no bubbles should be left on the template wall to avoid pores on the column surface after demolding. During the construction process, the frame rail device, track support device 1 should be checked for collision, track should not be knocked, track position, track gauge and level should be checked. If it is found that the acceptance standard is exceeded, it should be adjusted immediately. In order to ensure the elevation accuracy of the track line, the track support device 1 must be stable, and the condition of the track support device 1 should be observed at any time during the concrete pouring process to prevent the rod in the track support device 1 from falling off or deforming due to human factors, which may cause changes in the geometric size of the track line, deformation, and affect the quality of the line construction. After the concrete pouring is completed, the geotextile is covered, and the water should be maintained for 7 days to keep the geotextile wet. When the strength of the foundation concrete reaches 75% of the design value, the track support device 1 can be removed, and when the strength of the foundation concrete reaches 100% of the design value, the construction of the inspection pit bed of the prefabricated column is completed.

[0050] In this embodiment, the construction preparation and base treatment in step one include the following steps:

[0051] S1, the technical personnel investigate the site in advance, check the number and position of the base embedded parts, the height of the reserved steel bars, and the width of the foundation, and accept the quality of the prefabricated column 2 entering the site, to ensure that the appearance of the prefabricated column 2 has no cracks and damage, and the track bottom slope and bolt hole position meet the design requirements;

[0052] S2, the mechanical equipment required for construction is organized to enter the site, and the portal frame support 4 is installed on the track to be constructed after the portal frame support 4 meets the bearing capacity requirement through midas stress analysis, and 2-3 portal frame supports 4 are configured according to the construction requirements;

[0053] S3, according to the measured site construction limit data, a truck-mounted crane 3 for transporting and installing prefabricated columns 2 is customized, the body width of the truck-mounted crane 3 can be constructed within the construction area, and the rotating angle of the hook of the truck-mounted crane 3 is not less than 180°.

[0054] In the embodiment, the track support device 1 comprises a transverse support and a longitudinal support, the transverse support comprises a middle crossbar 11 and side crossbars 12 arranged on both sides of the middle crossbar 11, the middle crossbar 11 and the side crossbars 12 are connected through a support plate 19, a steel rail 6 is arranged on the support plate 19, the middle crossbar 11 and the side crossbars 12 are provided with transverse bolts 18 near one end of the support plate 19, the transverse bolts 18 can be used to adjust the gauge, the direction and the bottom slope of the track, by rotating and tightening the transverse bolts 18, the bolts can push the steel rail 6 inward or outward, so as to adjust the gauge and the direction of the track, when the error of the bottom slope is too large, the bottom of the steel rail 6 can be provided with a side pad, the transverse bolts 18 are tightened to fasten the upper side of the rail waist, the steel rail 6 will be inclined inward to form an inclined angle, so as to adjust the bottom slope of the track. The longitudinal support comprises two lead screws 13, the top ends of the two lead screws 13 are respectively vertically arranged through the side crossbars 12 on both sides of the middle crossbar 11 through threads, the bottom ends of the two lead screws 13 are respectively arranged vertically to the ground on both sides of the inspection pit, and the two lead screws 13 are used to adjust the height of the steel rail 6, by rotating the lead screw 13, the track height can be adjusted in millimeter level.

[0055] In the embodiment, the track support device 1 further comprises a track direction adjusting member, the track direction adjusting member comprises two cross arranged inclined struts 14, the two inclined struts 14 are threaded telescopic rods, the threaded telescopic rods comprise inner rods and outer rods, the inner rods and the outer rods are telescopically connected through threads, the top ends of the inner rods of the two inclined struts 14 are respectively connected with top supports 17 through threads, the top supports 17 are U-shaped, the top supports 17 are clamped with the bottom surface of the steel rail 6 and the track direction can be adjusted in millimeter level by rotating the top supports 17, the bottom ends of the two inclined struts 14 are respectively arranged in the column type inspection pit through anchor nails 15.

[0056] In the embodiment, the wedge-shaped pads 16 are arranged between the steel rail 6 and the support plate 19 for adjusting the bottom slope of the track, so that the bottom slope of the steel rail 1 / 40 is realized.

[0057] In the embodiment, the number of the track support device 1 is multiple groups, and the distance between the multiple groups of the track support device 1 is 2.5 m.

[0058] The above is only a preferred embodiment of the present application, and does not limit the present application, any simple modification, change and equivalent structure change made according to the technical essence of the present application to the above embodiment are still within the protection scope of the technical solution of the present application.

Claims

1. A construction method for a rail transit depot prefabricated column type maintenance pit top-down construction, characterized in that, Comprising the following steps: Step one, construction preparation and base treatment, draw the track layout, determine the number and detailed location of the in-store steel rails (6) and prefabricated columns (2); Step two, setting base marks: using the control base mark method, use the total station to set up encrypted base marks (7); Step three, spread the track material and install the track and fasteners: transport the track material and track support device (1) to the corresponding position respectively, hoist the steel rails (6) to the designed elevation position through the cooperation of the portal support (4) and the L ruler (5), install the track support device (1) below the steel rails (6) to support the steel rails (6), and install the fasteners on the steel rails (6) according to the position of the prefabricated column (2) in step one; Step four, track initial adjustment: according to the edge post and elevation data of the measured encrypted base marks (7), adjust the geometric state of the track according to the design and specification requirements through the cooperation of the L ruler (5) and the track support device (1); Step five, prefabricated column (2) transportation and installation: transport the prefabricated column (2) through the truck-mounted crane (3), hoist the prefabricated column (2) to the bottom of the fastener in step three, and connect the prefabricated column (2) and the fastener with bolt spikes to complete the installation of the prefabricated column (2); Step six, steel reinforcement binding and formwork installation: after all the prefabricated columns (2) are installed, the anchoring steel reinforcement in the inspection pit is twisted into the steel reinforcement connector pre-buried at the bottom of the prefabricated column (2), and after inspection, the concrete pouring formwork is installed at the bottom of the prefabricated column (2), and the formwork is ensured to be tight and not to leak grout; Step seven, track and prefabricated column (2) final adjustment: according to the real-time measurement data of the L ruler (5) and the track detector, the track support device (1) is used to make the final adjustment of the track geometric size and the verticality of the prefabricated column (2), and the acceptance is qualified; Step eight, foundation concrete pouring and curing: perform concrete pouring and water curing of the foundation concrete after the concrete pouring is completed, and when the strength of the foundation concrete reaches 75% of the design value, the track support device (1) can be removed, and when the strength of the foundation concrete reaches 100% of the design value, the construction of the prefabricated column inspection pit bed is completed.

2. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 1, characterized in that, The construction preparation and base treatment in step one includes the following steps: S1, conduct on-site investigation, review the number and position of the base embedded parts, the height of the reserved steel reinforcement, and the width of the foundation, and check the quality of the incoming prefabricated column (2); S2, organize the mechanical equipment to enter the site, and install the portal support (4) on the track to be constructed; S3, according to the measurement data of the on-site construction limit, customize the truck-mounted crane (3) for prefabricated column (2) transportation and installation, the body width of the truck-mounted crane (3) can be constructed within the construction area, and the hook rotation angle of the truck-mounted crane (3) is not less than 180°.

3. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 2, characterized in that, The track support device (1) comprises: The transverse support comprises a middle crossbar (11) and side crossbars (12) arranged on both sides of the middle crossbar (11), the middle crossbar (11) and the side crossbars (12) are connected by a support plate (19), a steel rail (6) is arranged on the support plate (19), and a transverse bolt (18) is arranged at an end of the middle crossbar (11) close to the support plate (19) and an end of the side crossbar (12) close to the support plate (19); The longitudinal support comprises two lead screws (13), the top ends of the two lead screws (13) are respectively arranged through the side crossbars (12) on both sides of the middle crossbar (11) in a threaded and vertical manner, the bottom ends of the two lead screws (13) are respectively arranged perpendicular to the ground on both sides of the inspection pit, and the two lead screws (13) are used for adjusting the height of the steel rail (6).

4. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 3, characterized in that, The track support device (1) further comprises a track direction adjusting member, the track direction adjusting member comprises two cross-arranged inclined struts (14), the two inclined struts (14) are both threaded telescopic rods, the top portions of the two inclined struts (14) are respectively provided with top supports (17), the top supports (17) are U-shaped, the top supports (17) are clamped with the rail bottom surface of the steel rail (6) and the track direction can be adjusted by rotating the top supports (17), and the bottom ends of the two inclined struts (14) are respectively arranged in the columnar inspection pit through anchor nails (15).

5. The construction method according to claim 3 or 4, characterized in that, The steel rail (6) and the support plate (19) are provided with wedge-shaped pads (16) for adjusting the rail bottom slope.

6. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 5, characterized in that, The number of the track support devices (1) is multiple groups, and the spacing between the multiple groups of track support devices (1) is 2.5 m.

7. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 5, characterized in that, The setting spacing of the encrypted base mark (7) in the second step is 5 m, and the positioning accuracy is ±2 mm.

8. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 7, characterized in that, After the track is preliminarily adjusted in the fourth step, the allowable deviation of the track levelness is ±10 mm, and the allowable deviation of the track gauge is +3 mm to -2 mm.

9. The reverse construction method of the prefabricated column-type maintenance pit of the rail transit depot according to claim 8, characterized in that, After the track and the column are finally adjusted in the seventh step, the track gauge is allowed to deviate by +2 mm to -1 mm, the track levelness is allowed to deviate by ±2 mm, the track direction error is not greater than 2 mm, the high-low error is not greater than 2 mm, the column perpendicularity is allowed to deviate by ±1°, the rail bottom slope is set according to 1 / 35 to 1 / 45, the track centerline is allowed to deviate by 5 mm, and the elevation is allowed to deviate by ±2 mm.

10. The construction method according to claim 1, characterized in that, The steel rail (6) joint is arranged centrally between the two prefabricated columns (2).

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