Structure for lengthening existing line round culvert of electrified railway

Abstract

The utility model relates to the technical field of electrified railway reconstruction construction, in particular to an electrified railway existing line round culvert lengthening structure which comprises a lengthening round culvert and a steel casing, and the size of the steel casing is smaller than that of an existing round culvert and that of the lengthening round culvert. And one end of the steel casing penetrates through the existing supporting and blocking body and is inserted into the existing round culvert, and the other end of the steel casing is located outside the existing supporting and blocking body and is inserted into the lengthened round culvert, so that the existing round culvert and the lengthened round culvert are lengthened. The utility model has the advantages that the structure is simple, the stress is stable, the butt joint of the existing round culvert and the lengthened round culvert is realized, and the connection performance between the existing round culvert and the lengthened round culvert is ensured; and construction is easy and convenient, the prefabrication degree is high, the transformation construction amount of an existing structure is relatively small, and the method is suitable for popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of electrified railway reconstruction construction, in particular to a structure for extending an existing circular culvert of an electrified railway. Background Art

[0002] During the reconstruction and expansion of existing operating railway lines, existing culverts need to be extended and reconstructed in parallel sections with small line spacing. However, when the culvert is extended, the total length after the extension often exceeds the limited length. In the design, the extended part often uses culvert sections with larger apertures or higher clear heights to meet the requirements of the limited length and improve the working conditions for maintenance and repair. At the same time, when the existing culvert is extended, it is often necessary to cross existing boundary structures, such as eight-shaped walls; when the existing culvert with different apertures and clear heights is connected to the extended culvert, a large misalignment gap is generated between the culvert sections and at the crossing position, the roadbed soil will be poured into the culvert along the gap, and such problems are more likely to occur between the extended culvert and the existing structure. Summary of the invention

[0003] The purpose of the utility model is to provide a structure for extending the existing circular culvert of an electrified railway based on the above-mentioned deficiencies in the prior art, by means of an inserted steel casing having a diameter smaller than that of the existing circular culvert and the extended circular culvert to carry out the butt connection between the existing circular culvert and the extended circular culvert and the crossing of the existing structure, thereby improving the quality of the reconstruction construction.

[0004] The purpose of this utility model is achieved by the following technical solutions:

[0005] A structure for extending an existing circular culvert of an electrified railway line, comprising an existing circular culvert buried in an existing line bed and an existing retaining body arranged at a boundary position of the existing line bed, characterized in that it comprises an extended circular culvert and a steel casing, the size of the steel casing is smaller than that of the existing circular culvert and the extended circular culvert, and one end of the steel casing passes through the existing retaining body and is inserted into the existing circular culvert, and the other end of the steel casing is located outside the existing retaining body and is inserted into the extended circular culvert, thereby realizing the extension between the existing circular culvert and the extended circular culvert.

[0006] A newly built eight-shaped wall is arranged at the boundary position of the extended circular culvert.

[0007] The periphery of the extended circular culvert is provided with encapsulating concrete.

[0008] The extended circular culvert adopts a prefabricated assembly structure composed of a plurality of prefabricated segments.

[0009] The steel casing is made of a metal iron pipe, the outer surface of which is coated with a rust-proof agent.

[0010] The connection between the steel casing and the existing circular culvert is filled with polyvinyl chloride cement and sealed with epoxy cement mortar.

[0011] The advantages of the present utility model are as follows: simple structure, stable force-bearing, realizing the butt joint of the existing circular culvert and the extended circular culvert, ensuring the connection performance between the two; simple and convenient construction, high degree of prefabrication, relatively small construction volume for the transformation of the existing structure, and suitable for popularization. Brief Description of the Drawings

[0012] Figure 1 It is a structural schematic diagram of the present utility model. Detailed Description of the Preferred Embodiment

[0013] The features of the present utility model and other related features will be further described in detail below in conjunction with the drawings through embodiments for the understanding of those skilled in the same industry:

[0014] As Figure 1 shown, the markings 1-8 in the figure respectively represent: existing line subgrade 1, catenary column 2, existing circular culvert 3, existing splayed wing wall 4, extended circular culvert 5, steel casing 6, packed concrete 7, newly built splayed wing wall 8.

[0015] Embodiment: As Figure 1 shown, the existing line circular culvert extension structure in this embodiment is used for the extension construction of the existing circular culvert 3 buried in the existing line subgrade 1, and an existing splayed wing wall 4 as a retaining structure is arranged at the boundary position of the existing circular culvert 3. A catenary column 2 for supporting the existing line catenary is established above the existing line subgrade 1.

[0016] As Figure 1 shown, the structure in this embodiment includes an extended circular culvert 5, which is a circular culvert extension section extending outward from the existing line, and it is connected with the existing circular culvert 3 through a steel casing 6. Specifically, the outer contour shape of the steel casing 6 is adapted to the inner contour shapes of the existing circular culvert 3 and the extended circular culvert 5, and the size is smaller than that of the existing circular culvert 3 and the extended circular culvert 5. One end of the steel casing 6 passes through the existing splayed wing wall 4 and is inserted into the existing circular culvert 3, and the other end of the steel casing 6 is located outside the existing splayed wing wall 4 and is inserted into the extended circular culvert 5, realizing the extension between the existing circular culvert and the extended circular culvert, and at the same time realizing the crossing of the existing splayed wing wall 4. Since the steel casing 6 is a prefabricated component, there is no need to demolish the existing splayed wing wall 4.

[0017] Packed concrete 7 is arranged around the steel casing 6 and the extended circular culvert 5. On the one hand, the height of the extended circular culvert 5 is adjusted to be the same as that of the existing circular culvert 3, and on the other hand, the extended circular culvert 5 and the steel casing 6 are also protected.

[0018] A newly built splayed wing wall 8 is arranged at the outer boundary position of the extended circular culvert 5.

[0019] When this embodiment is specifically implemented, it includes the following construction methods:

[0020] The construction process is as follows: relocation of existing line protection fence → prefabrication of circular culvert and production of steel casing → foundation construction → installation of steel casing → installation of concrete pipe segments → waterproof layer and settlement joints → sealing, opening paving and wing wall construction → curing → backfilling.

[0021] The key steps include the following:

[0022] The production of the extended circular culvert 5 and the steel casing 6: the construction method of prefabrication before installation is adopted. The circular pipes are centrally prefabricated in the prefabrication yard, and the template adopts a standardized steel mold. The length of each section of the positive pipe is 1m. The construction process of the culvert is cast and formed.

[0023] According to the curvature of the inner and outer ring reinforcements of the extended circular culvert 5, a circular template is made, and the ring reinforcement is shaped using the template. When tying, first draw the positions of several groups of circular and longitudinal reinforcements on the embedded reinforcement and arc surface of the pipe seat, and tie according to the drawn positions. These groups of steel bars are used as control bars for other steel bars and are fixed. Other steel bars are tied based on the control bars. Short steel bars are used to fix their spacing and protective layer.

[0024] The template is divided into inner and outer templates, and sponge strips are added between the templates to prevent leakage. The inner template is fixed on a circular steel frame supported by embedded reinforcement on the arc-shaped surface of the pipe seat, and the outer template is fixed on the inner template by a tension card, and the distance between the inner and outer templates is controlled by the card to be 35cm. A circular tension bar is set every 2m on the outside of the outer template to reinforce the template.

[0025] When pouring the culvert, a construction platform is set up and a manual shovel is used to enter the warehouse. When unloading materials, a dedicated person is assigned to direct and coordinate them uniformly to ensure balanced unloading and leveling of materials in layers to avoid the phenomenon of concentrated unloading. Concrete vibration is carried out symmetrically using an inserted vibrator and an attached vibrator.

[0026] The inserted steel casing 6 is made of a metal iron pipe, the outer diameter of which is 2-3 cm smaller than the inner diameter of the existing circular culvert, and is coated with a rust preventive agent.

[0027] Foundation construction: After the existing line width roadbed is processed to the bottom elevation of the drainage culvert foundation, the foundation concrete and gravel cushion layer can be constructed. The template uses a combined steel template, the template is connected with a U-shaped card, and the back support of the steel template uses square wood, wooden wedges, steel bars, pipe steel and other materials to support the side of the foundation excavation.

[0028] The foundation concrete is centrally mixed at the mixing station, transported to the site by concrete tank trucks, and fed into the formwork by cranes equipped with funnels, and compacted by vibrating rods. According to the requirements of the settlement joint structure, the foundation concrete is poured in blocks. The concrete pouring is carried out continuously. Since the amount of concrete in each foundation block is not large, it is poured in one go, and the concrete is ensured to be compacted by vibration.

[0029] Installation of steel casing 6: First, use tools such as sandpaper and wire brushes to remove the rust layer on the surface of the metal steel pipe, restore the smooth surface of the steel pipe, and apply a special rust inhibitor on the surface of the metal steel pipe to form a protective film to block the contact of oxygen and moisture, effectively delaying the occurrence of rust.

[0030] Before installing the steel casing, first clean the impurities in the existing drainage circular culvert, and insert the customized steel casing into the existing circular culvert. Fill polyvinyl chloride mastic at the connection between the steel casing and the culvert pipe, and seal it with M20 epoxy cement mortar. Insert Φ16 threaded steel bars into the existing flared wall or straight wall as fixed steel bars.

[0031] Installation of the extended pipe section of circular culvert 5: The curing time shall not be less than 14 days. When the strength of the circular pipe concrete reaches 100%, it can be transported to the site by truck and hoisted by a crane with manual assistance for installation. During installation, there should be a special person in command to avoid collision of the pipe sections and damage to the pipe sections.

[0032] Waterproof layer and settlement joint: The culvert adopts Type A waterproof layer construction. Before construction, its surface should be cleaned and dried. Lay asphalt-impregnated linen waterproof layer at the pipe joint and settlement joint.

[0033] A settlement joint is set every 1 - 5 m of the culvert body, with a width of 3 cm. The settlement joints should be aligned vertically and penetrate the abutment body and foundation. The settlement joint materials of the culvert body are plastic clay, one layer of chlorinated polyethylene waterproof coiled material, and two layers of polyurethane waterproof coating.

[0034] Encasement, portal paving and wing wall construction: After the pipe section is installed, set up the formwork for the pipe seat. After the formwork is inspected and qualified, carry out concrete pouring construction.

[0035] The entrance and exit foundation and wing wall foundation adopt C25 concrete. The entrance and exit vertical aprons, slopes, and channel bed cones are made of mortar rubble masonry, with a crushed stone cushion layer laid below. The rubble stones are selected as those without weathering, water rust, cracks, and with a compressive strength greater than 30 Mpa. When masonry, it is required that the mortar is full and dense. The staggered joints should meet the specification requirements, and the mortar is tested according to the technical specification requirements.

[0036] Curing: Concrete curing: After the concrete is poured, it should be covered and watered within 12 hours. Use a permeable geotextile with good moisture retention effect to cover and sprinkle water for curing; when using plastic sheeting for covering and curing, the surface of the freshly poured concrete should be covered tightly with plastic sheeting, and there should be condensate water inside the plastic sheeting, and it should be checked regularly. The curing time shall not be less than 15 days.

[0037] Backfilling: The backfilling material is filled with pervious materials such as gravel and graded crushed stone that meet the design requirements. The pervious materials have a reasonable gradation. The content of fine materials passing through the 0.074 mm sieve hole in the particles less than 2 cm is not more than 10%, and the maximum particle size of the filler is not more than 50 mm.

[0038] The backfilling work is carried out by manual cooperation with machinery. For the parts closer to the culvert, small machinery is used for ramming and filling, and for the parts farther away, a roller is used for compaction.

[0039] Subgrade filling on the top surface of the culvert: It can only be carried out after the concrete strength of the culvert body reaches 100%. When the soil cover thickness on the top of the culvert is less than 1 m, heavy machinery is prohibited from passing.

[0040] Although the above embodiments have detailed the concept and embodiments of the purpose of the present invention with reference to the accompanying drawings, those of ordinary skill in the art can recognize that various improvements and transformations can still be made to the present invention without departing from the scope defined by the claims. Therefore, they are not elaborated one by one here.

Claims

1. A structure for extending an existing circular culvert of an electrified railway, comprising an existing circular culvert buried in an existing line bed and an existing retaining body arranged at a boundary position of the existing line bed, characterized in that: It includes an extended circular culvert and a steel casing, the size of the steel casing is smaller than the existing circular culvert and the extended circular culvert, and one end of the steel casing passes through the existing supporting body and is inserted into the existing circular culvert, and the other end of the steel casing is located outside the existing supporting body and is inserted into the extended circular culvert, so as to realize the extension between the existing circular culvert and the extended circular culvert.

2. The structure for connecting the existing circular culverts of an electrified railway according to claim 1, characterized in that: A newly built eight-shaped wall is arranged at the boundary position of the extended circular culvert.

3. The structure for connecting the existing circular culverts of an electrified railway according to claim 1, characterized in that: The periphery of the extended circular culvert is provided with encapsulating concrete.

4. The structure for connecting the existing circular culverts of an electrified railway according to claim 1, characterized in that: The extended circular culvert adopts a prefabricated assembly structure composed of a plurality of prefabricated segments.

5. The structure for connecting the existing circular culverts of an electrified railway according to claim 1, characterized in that: The steel casing is made of a metal iron pipe, the outer surface of which is coated with a rust-proof agent.

6. The structure for connecting the existing circular culverts of an electrified railway according to claim 1, characterized in that: The connection between the steel casing and the existing circular culvert is filled with polyvinyl chloride cement and sealed with epoxy cement mortar.

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