A method for bridge reconstruction

Abstract

The present invention relates to the field of building construction technology, and in particular to a method for bridge reconstruction; the method comprises the following steps: S1: after constructing a temporary beam fulcrum, construct a temporary beam for supporting an existing bridge; S2: construct an existing slope, and form a new slope by sloping; S3: construct a new bored pile foundation, construct a new cap, the new cap is connected to the existing bridge abutment foundation, and a concrete slab wall is set between the new cap and the existing cap beam; S4: remove the temporary beam and the temporary beam fulcrum in S1; S5: pour concrete on the new slope to form a road-bridge transition zone, and construct a road surface layer above the road-bridge transition zone; S6: construct a new railway line under the existing bridge. The present invention reinforces the existing abutment and slopes the existing slope, and uses the existing slope for the construction of the new railway line, so that the new railway line is constructed without affecting the existing railway line, and there is no need to bypass the existing bridge or demolish the existing bridge, which can save costs and shorten the construction period.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a method for bridge reconstruction. Background Art

[0002] When a railway passes under a highway, the economical and reasonable approach is to make the middle span of the highway bridge larger than the side span to obtain a larger clear width for passage, allowing the railway to pass through the middle span and use the side span to cross the railway cutting. When a new line is built near an existing railway, the closer the new line is to the existing line, the less new land and investment can be saved while ensuring the normal use of the existing railway. When a new railway line encounters a road bridge that intersects with a highway or railway, it is usually chosen to bypass the section with an overpass to build a new route, or to demolish the existing bridge at the intersection and rebuild it. However, the construction of a new route bypassing the existing line will cause new land acquisition, demolition, and increased investment; demolishing the old bridge for reconstruction will waste resources because the demolished existing bridge often does not reach the original design service life, and will extend the construction period and increase investment costs. Therefore, a method of bridge reconstruction is urgently needed to solve the above problems. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a method for bridge reconstruction, comprising the following steps:

[0004] S1: After constructing the temporary beam support point on the side close to the existing abutment, the temporary beam is used to support the existing bridge;

[0005] S2: construct the existing slope and reduce the existing slope to form a new slope;

[0006] S3: construct a new bored pile foundation, and construct a new cap on the new bored pile foundation. The new cap is connected to the existing abutment foundation, and a concrete slab wall is set between the new cap and the existing cap beam.

[0007] S4: Remove the temporary beam and its support points in S1;

[0008] S5: pouring concrete on the newly built slope to form a road-bridge transition zone, and constructing the pavement layer above the road-bridge transition zone;

[0009] S6: Construction of a new railway line under an existing bridge.

[0010] Furthermore, in the step S1, at least two temporary beam fulcrums are provided, a temporary beam is provided above the temporary beam fulcrum, and the temporary beam fulcrums at both ends of the temporary beam are located outside the existing bridge.

[0011] Furthermore, in step S1, the construction steps of the temporary beam support point are as follows: after the construction of the cast-in-place piles at the lower end is completed, a temporary beam pier is constructed above the cast-in-place piles.

[0012] Furthermore, in the step S1, the temporary beam is a Bailey beam.

[0013] Furthermore, in step S3, a plurality of the new bored pile foundations are constructed and arranged side by side along the existing abutment foundation, the new bored pile foundations and the existing abutment foundations are arranged alternately, and the newly built pedestal above the new bored pile foundation is located below the existing cap beam.

[0014] Furthermore, the newly built abutment is mounted on the existing abutment foundation so that the existing abutment foundation and the new bored pile foundation form a whole.

[0015] Furthermore, in step S3, after the construction of the concrete slab wall is completed, the existing abutment is encapsulated with concrete.

[0016] Furthermore, the concrete slab wall is a cast-in-place concrete part or a prefabricated concrete part.

[0017] Furthermore, in step S2, the newly built slope is step-shaped and extends to the bottom of the pavement layer structure.

[0018] Furthermore, in step S2, the existing slope below the existing bridge is constructed to form a roadbed, and a new railway line is constructed on the roadbed.

[0019] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0020] 1) The bridge reconstruction method provided by the present invention reinforces the existing abutments of the existing bridges and slopes the existing slopes, and forms a roadbed for the existing slopes below the existing bridges after construction, which is used to build a new railway line. The new railway line is constructed without affecting the existing railway line, and there is no need to bypass the existing bridges or demolish the existing bridges, which can save costs and shorten the construction period;

[0021] 2) In the bridge reconstruction method provided by the present invention, the existing slope is sloped and a new stepped slope is formed. Concrete is poured on the new slope to form a road-bridge transition zone. The new stepped slope can strengthen the connection with the road-bridge transition zone to avoid side sliding;

[0022] 3) In the bridge reconstruction method provided by the present invention, new bored pile foundations and existing abutment foundations are arranged alternately and distributed side by side, and the newly built abutment is connected to the existing abutment to make the new bored pile foundation and the existing abutment foundation connected as a whole, thereby enhancing the stress of the existing abutment foundation, and a concrete slab wall is arranged between the newly built abutment and the existing cap beam, so that the existing cap beam can be evenly stressed, thereby ensuring the stability of the existing bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the bridge after the bridge reconstruction is completed in the bridge reconstruction method of the present invention;

[0024] Figure 2 A schematic diagram of the structure of an existing bridge in the bridge reconstruction method of the present invention;

[0025] Figure 3 A schematic cross-sectional view of an existing bridge in the bridge reconstruction method of the present invention;

[0026] Figure 4 It is a construction schematic diagram of the bridge reconstruction method of the present invention;

[0027] Figure 5 In the method for bridge reconstruction of the present invention Figure 4 Schematic cross-section of

[0028] Figure 6 It is a construction schematic diagram of the bridge reconstruction method of the present invention;

[0029] Figure 7 In the method for bridge reconstruction of the present invention Figure 6 Schematic cross-section of

[0030] Figure 8 It is a construction schematic diagram of the bridge reconstruction method of the present invention;

[0031] Fig. 9 A schematic diagram of the structure of a newly built slope in the bridge reconstruction method of the present invention;

[0032] Fig.10 It is a structural schematic diagram of the existing bridge abutment reinforcement in the bridge reconstruction method of the present invention;

[0033] 1-existing railway; 2-existing bridge; 3-existing bridge piers; 4-existing bridge abutments; 41-anchor reinforcement; 5-existing slope; 6-existing cap beam; 7-temporary beam support; 8-temporary beam; 9-new slope; 10-new bored pile foundation; 11-new pedestal; 12-concrete slab wall; 13-road-bridge transition zone; 14-pavement layer; 15-new railway line. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the drawings, the size and relative size of some parts may be enlarged for clarity.

[0035] In the description of the present invention, unless otherwise clearly stipulated and limited, the terms "connection" and "connected" should be interpreted in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the description of the present invention, terms such as "up", "down", "left", "right", "front", "back", etc., and the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0037] In addition, in the description of the present invention, the terms "first" and "second" are only used to distinguish in the description.

[0038] The present invention provides a bridge reconstruction method, which can be used to add a railway line under an existing bridge, or to add a railway line under a road bridge where a road and a railway intersect, as shown in the attached manual. Figure 2-3 As shown, the existing bridge structure of this embodiment includes an existing railway 1, an existing bridge 2, existing bridge piers and foundations, existing bridge abutments and foundations, and an existing slope 5. The existing railway 1 is arranged below the existing bridge 2, and an existing cap beam 6 is arranged above the existing bridge piers 3 and the existing bridge abutments 4. The newly built railway line passes under the existing bridge structure. The construction method includes the following steps:

[0039] S1: After constructing a temporary beam support 7 on the side close to the existing abutment 4, construct a temporary beam 8 to support the existing bridge 2;

[0040] S2: construct the existing side slope 5, and reduce the existing side slope 5 to form a new side slope 9;

[0041] S3: construct a new bored pile foundation 10, and construct a new cap 11 on the new bored pile foundation 10, the new cap 11 is connected to the existing abutment foundation, and a concrete slab wall 12 is set between the new cap 11 and the existing cap beam 6;

[0042] S4: dismantle the temporary beam 8 and the temporary beam support 7 in S1;

[0043] S5: pouring concrete on the newly built slope 9 to form a road-bridge transition zone 13, and constructing a pavement layer 14 above the road-bridge transition zone 13;

[0044] S6: Construct a new railway line 15 under the existing bridge 2.

[0045] There is a railway line under the existing bridge structure, and there are slopes on both sides of the existing bridge 2. When the best route for the new railway line 15 is to pass under the existing bridge structure, the space under the existing bridge structure is too small to meet the clearance and linear layout design requirements of the new railway line 15. The new railway line 15 needs to bypass the existing bridge structure, or demolish the existing bridge at the intersection and rebuild it. However, the construction of the new route bypassing the existing line will cause new land acquisition, demolition, increased investment, etc. The demolition of the old bridge for reconstruction will waste resources because the demolished existing bridges often do not reach the original design service life, and will also lead to an increase in construction period and investment costs. Therefore, the above-mentioned bridge reconstruction method adds a temporary beam 8 to the existing bridge 2 for support, and then reconstructs the existing slope 5, and slopes the existing slope 5 to form a new slope structure. After the above-mentioned reconstruction, without affecting the continued use of the existing bridge 2, the construction area of ​​the new railway line 15 is added, and the smooth layout of the new railway line or highway line is achieved, as shown in the attached manual. Figure 1 The figure shows the structural diagram of the existing bridge after reconstruction.

[0046] Specifically, before the bridge is reconstructed, it is necessary to investigate the data of the existing bridge structure and conduct a field survey to understand the safe construction range and block the existing bridge traffic until the pavement layer 14 is constructed above the road-bridge transition zone 13 and the surrounding construction of the pavement is completed before resuming traffic.

[0047] Optimize the implementation method, as shown in the attached manual Figure 4-5 As shown, in the step S1, at least two temporary beam fulcrums 7 are set, and the temporary beam fulcrums 7 are located on the outside of the existing bridge 2, which does not affect the construction of the existing slope 5 below the existing bridge 2. After the construction of the temporary beam fulcrum 7 is completed, a temporary beam 8 is set above the temporary beam fulcrum 7, and the end fulcrum of the existing bridge 2 is replaced on the temporary beam 8, which is convenient for the later construction of the existing abutment and foundation. The replacement of the existing bridge 2 can be to set a jack on the temporary beam 8, or to lift the existing bridge 2 by a crane to support the temporary beam 8; the construction steps of the temporary beam fulcrum 7 are that after the construction of the cast-in-place piles at the lower end is completed, a temporary pier is constructed above the cast-in-place piles.

[0048] The detailed implementation method is to construct the bored piles in the buried part. The specific construction process is as follows:

[0049] Survey and lay out - cast hole guard ring - cast retaining wall and dig hole - make steel cage - hoist steel skeleton - pour concrete. After the bored pile construction is completed, construct military piers above the bored piles. After the overall construction of the temporary beam fulcrum 7 is completed, set the temporary beam 8 above the temporary beam fulcrum 7. The temporary beam 8 can be a Bailey beam, which can support the end point of the existing bridge 2.

[0050] Optimize the implementation method, as shown in the attached manual Fig. 9As shown, the existing slope 5 is subjected to slope reduction construction, and the existing slope 5 below the existing bridge 2 is constructed to form a roadbed for building a railway or a highway, and then the outer side of the existing abutment 4 is subjected to slope reduction processing. Preferably, the newly-built slope 9 is in the shape of steps, extending to the bottom of the pavement layer structure, a crushed stone cushion layer is laid on the lower layer of the newly-built slope 9, and then the upper concrete surface layer is leveled. The concrete can be C20 concrete, and the lower end of the newly-built slope 9 extends to connect with the existing abutment foundation.

[0051] Optimize the implementation method, as shown in the attached manual Figure 6-7 As shown, a plurality of new bored pile foundations 10 are constructed at one end of the existing bridge 2, and the new bored pile foundations 10 are arranged side by side along the existing abutment foundations, and the new bored pile foundations 10 and the existing abutment foundations are arranged alternately. Specifically, a new bored pile foundation 10 is arranged on the outside of the outermost existing abutment foundation, and a new bored pile foundation 10 is arranged between two adjacent existing abutment foundations, and the new bored pile foundation 10 is arranged in the middle of the two existing abutment foundations, and a new cap 11 is arranged above the new bored pile foundation 10, and the new cap 11 is connected to the existing abutment foundation, and the new cap 11 is sleeved on the existing abutment foundation so that the existing abutment foundation and the new bored pile foundation 10 form a whole, and the new bored pile foundation 10, the new cap 11 and the existing abutment foundation can be used as a new abutment foundation, and the thickness of the sediment at the bottom of the new bored pile foundation 10 is not more than 10 cm; the newly built abutment 11 above the new bored pile foundation 10 is located below the existing cap beam 6, and a concrete slab wall 12 is constructed between the newly built abutment 11 and the existing cap beam 6. The existing cap beam 6 can be uniformly stressed on the concrete slab wall 12, and the existing abutment 4 is encapsulated. The concrete slab wall 12 is a cast-in-place concrete part or a prefabricated concrete part. The specific construction method is to encapsulate the pile foundation of the existing abutment 4 when casting the concrete slab wall to form a whole, or to first install the concrete slab wall prefabricated part, and then encapsulate the concrete slab wall prefabricated part and the pile foundation of the existing abutment 4 to complete the construction.

[0052] Specifically, the construction process of the new bored pile foundation 10 is as follows:

[0053] Measurement, layout and positioning of piles - pouring of retaining ring at the hole mouth - installation of vertical transport frame - installation of electric hoist or winch - installation of movable bottom bucket, movable cover, lighting, water pump and ventilator - excavation of pile hole - detection of center position of pile foundation - placement of additional steel bars, retaining wall (pile body) formwork - pouring of retaining wall (pile body) concrete - removal of retaining wall (pile body) formwork - inspection and acceptance - installation of string tube or chute.

[0054] (1) Measurement, setting out and stake location

[0055] The pile position, length and type of the design drawings are reviewed. Once they are correct, the bored pile position is laid out based on the length between the center point of the newly built box bridge that has been accurately laid out on the line and the bored piles that need to be constructed. After the layout self-checks and there are no errors, the next step of construction is carried out.

[0056] (2) Casting of hole guard ring

[0057] The hole mouth guard ring is cast with concrete, and the hole mouth guard ring is 30cm higher than the original ground. After the construction of the hole mouth guard ring is completed, the elevation of the top of the hole mouth guard ring is measured, and the excavation depth is determined based on the elevation of the hole mouth guard ring and the elevation of the pile bottom. After the construction of the guard ring is completed, the pile position is re-measured, and the cross guard pile is positioned on the top surface of the guard ring. During the excavation construction process, the cross guard pile is used to detect the center deviation of the pile hole, the pile diameter, the verticality of the pile hole, etc.

[0058] (3) Install the vertical transport rack

[0059] The vertical transport frame adopts a lifting steel frame as the load-bearing structure and is equipped with a slow winch base for lifting. The height of the vertical transport frame shall not exceed 0.8m, and the distance from the line center to the line side shall not be less than 1.875m.

[0060] (4) Install electric hoist or winch

[0061] Install the pulley block and electric hoist on the vertical transport frame, put on the winch wire rope, install the winch at the appropriate position, and use a wheelbarrow or a small dump truck to transport the soil on the ground.

[0062] (5) Install movable bottom bucket, movable cover, lighting, water pump and ventilator

[0063] (6) Excavation of pile holes

[0064] When excavating the pile hole, first excavate the soil in the middle part of the pile hole, then expand the excavation to the periphery, control the cross-sectional size of the pile hole, and determine the height of the excavation section according to the different soil qualities. The advance of each cycle is about 1.0m. After the excavation is completed, the concrete retaining wall must be poured immediately.

[0065] Starting from the second section, soil is transported using lifting equipment, and operators inside and outside the pile hole take safety measures. The pile hole is dug to the specified depth, and the diameter of the hole and the arc of the well wall are checked with a rod hole gauge. The construction workers trim the hole wall to make it vertical and straight.

[0066] (7) Pile foundation center position detection

[0067] After the excavation of each segment pile hole is completed, it is necessary to check the hole diameter, verticality and center deviation, so that after each segment hole is excavated and formed, the hole center is as close to the pile center as possible, with a deviation of no more than 5cm and an inclination of no more than 0.5%, so as to ensure the wall thickness, hole diameter and verticality of the entire pile foundation.

[0068] (8) Place additional reinforcement and support wall (pile body) formwork

[0069] After the excavation of each segment pile hole is completed, additional steel bars are placed between two adjacent segments. The retaining wall (pile body) template is repeatedly used by removing the upper section and supporting the lower section. Preferably, the template can be reinforced with wooden piles, where the axis and the center of the pile are on the same vertical line with a deviation of no more than 1 cm to ensure that the verticality of the pile foundation meets the requirements of the specification and the pile diameter is not less than the designed pile diameter.

[0070] (9) Pouring of retaining wall (pile body) concrete

[0071] After each section is excavated, the formwork is immediately placed and the retaining wall (pile body) concrete is poured by hand and vibrated, and the slump is controlled within 10cm. The concrete retaining wall must ensure the strength and thickness of the concrete. According to the climatic conditions, excavation can only be carried out after it has passed the inspection and the concrete strength is not less than 2.5MPa.

[0072] (10) Removal of retaining wall (pile body) formwork

[0073] After checking that the pile hole diameter, arc angle and center position are qualified, the first section of the retaining wall (pile body) formwork is removed and additional reinforcement is placed. The retaining wall (pile body) formwork is generally used in turn by removing the upper section and supporting the lower section. A concrete pouring opening with a height of 10 cm is left at the top of the formwork.

[0074] (11) Inspection and acceptance

[0075] After the above construction is accepted, the steel cage is hoisted and placed in sections while being welded.

[0076] (12) Install string tube or slide pipe

[0077] In order to prevent concrete segregation, a string tube is used to pour solid bored pile concrete, and the height of the string tube outlet material from the concrete pouring surface shall not exceed 1m.

[0078] After the construction is completed, the new bored pile foundation 10 is inspected and accepted. During the construction of the new bored pile foundation 10, the distance between the new bored pile foundation 10 and the pile foundation of the existing abutment must be ensured to avoid affecting the pile foundation of the existing abutment during the construction of the new bored pile foundation 10. In this embodiment, the newly built cap 11 is arranged above the new bored pile foundation 10. The new bored pile foundation 10 serves as the pile foundation of the newly built cap 11, and the steel bar production and installation can be constructed together.

[0079] After the reinforcement of the newly built abutment 11 is completed, the reinforcement frame of the newly built abutment 11 should be wrapped on the outside of the pile foundation of the existing abutment 4 to ensure that the newly built abutment 11 forms a whole with the new bored pile foundation 10 and the existing abutment 4; after the reinforcement is completed, the abutment template is made and installed. In this embodiment, for the convenience of assembly, the integral large-block template is directly assembled, and the template adopts a combination template assembled with standard sections of fixed size and adjustment sections. Preferably, the abutment template panel uses 6mm thick steel plate, the horizontal small ribs use flat steel 100mm×10mm, arranged at a spacing of 355mm, and the vertical ribs use channel steel, arranged at a spacing of 350mm; the template is reinforced with steel pipes, wherein the spacing of the vertical double-row steel pipes is 0.7m, and the steel pipes at the four corners are locked with fasteners. Preferably, the top of the abutment is pulled and triangularly locked with steel pipes, and the vertical steel pipes are externally provided with a support frame pipe, one end of which supports the template and the other end is supported on the frame pipe of the foundation pit slope. After the template is hoisted and spliced, check the center line, the dimensions of each part of the template, the top surface elevation, the flatness of the template surface and the misalignment between the plate joints, etc. After the template is adjusted and corrected to meet the requirements, it can be reinforced, and then the oil and debris inside and on the surface of the template are cleaned, and the release agent is applied on the template surface before pouring concrete. The concrete pouring of the new foundation is poured from both ends to the middle at the same time, and poured in layers, each layer is 30cm. When pouring concrete from a high place into the template, concrete segregation should be prevented, and its free fall height should not exceed 2m. The pouring of concrete should be carried out continuously. When the gap is interrupted for some reason, the interruption time should be less than the initial setting time of the previous layer of concrete. After the concrete is poured, it should be compacted and smoothed before the top concrete is initially set. After the concrete is finally set and the concrete compressive strength is greater than or equal to 2.5MPa, the foundation template is removed.

[0080] After the construction of the new cap 11 is completed, a concrete slab wall 12 is constructed between the new cap 11 and the existing cap beam 6. The specific construction process is to roughen the pile foundation of the existing abutment 4, plant reinforcement, tie the reinforcement and then pour concrete. In addition to roughening the old concrete, an interface agent is also used for bonding, as shown in the attached manual. Fig.10 The figure shows the schematic diagram of the existing bridge abutment reinforcement.

[0081] (I) The construction process of planting reinforcement is:

[0082] (1) Drilling: Use a small diameter drill bit and a steel bar detector to drill holes. After confirming that there is no main reinforcement, use a large diameter drill bit to drill holes. The hole depth should be the same as the buried depth of anchor bar 41. The hole diameter should be 2 to 4 mm larger than the anchor bar. The hole position should avoid structural reinforcement and the hole channel should be straight.

[0083] (2) Cleaning the drilled hole: First clean the hole with a stiff bristle brush, then use high-pressure dry air to blow away dust, debris and moisture at the bottom of the hole. The hole should be kept dry.

[0084] (3) Glue pouring: The anchoring glue is poured from the bottom of the hole to 2 / 3 of the hole depth. After the anchor bar 41 is inserted, the glue fills the entire hole.

[0085] (4) Inserting anchor bars: Before inserting anchor bar 41, the surface dirt of the insertion part should be cleaned and the anchor bar should be inserted to the bottom of the hole. The excess glue at the hole mouth should be removed. The dirt should be removed with a steel brush first, then wiped with acetone and wiped dry.

[0086] (5) Before the adhesive dries, avoid disturbing the anchor bars or leaving open water near the hole.

[0087] (II) Concrete slab wall construction process:

[0088] (1) Surface treatment of old concrete: Clean all surfaces of the existing abutment 4 that are in contact with the concrete slab wall 12, and remove dust, loose materials, plaster, grease, corrosion deposits or algae. Roughen the surface by gently chiseling or sandblasting, and remove the loose skin to expose the solid aggregate of the old concrete, and then rinse it with high-pressure water. Before pouring new concrete, the old concrete surface must be kept in a dry and saturated state.

[0089] (2) Prepare interface adhesive.

[0090] (3) Applying interface glue: Apply the prepared interface glue to the saturated dry surface of the existing bridge abutment old concrete with a brush or spray gun, and completely cover the old concrete. Spray gun can be used for spraying. The colloid spraying should be uniform and spread all over the spraying surface. After applying one layer, let the interface glue penetrate into the concrete. After it becomes gelled, apply the second layer and use it as a bonding layer. The coating thickness of the two layers of interface glue should be controlled to be no less than 0.3 liters / m 2 , the thickness of the applied interface glue layer should not exceed 1mm.

[0091] (4) Pouring new concrete: After applying the prepared interface glue on the surface of the old concrete, set up the steel structure of the concrete slab wall, and promptly pour the newly mixed concrete to form the concrete slab wall 12. The process of pouring the newly mixed concrete should be completed within the applicable period of the interface glue. The anchor bars 41 at the extension of the existing abutment 4 are inserted into the concrete slab wall to further reinforce the concrete slab wall 12. For example, the Swiss Sika interface glue Sikadur32LP, in an environment with a temperature of 25°C or below, should be controlled within 8 hours from the mixing of the interface glue to the pouring of the new concrete at the interface. If the ambient temperature exceeds 25°C, or the amount of interface glue is large (the more glue is added, the slower the heat dissipation, and the heat accumulation will accelerate the curing), the pouring time should be appropriately reduced and should not exceed 4 hours, and it must be determined through experiments. Do not pour the newly mixed concrete directly after the interface glue is dry; if the applied interface glue has dried, apply the interface glue again and repeat the above process.

[0092] (5) Curing of interface adhesive: After pouring new concrete, the interface adhesive should be cured. When the temperature is not lower than 15°C, it should be cured for 72 hours. If the curing temperature is lower than 15°C, it should be cured for 7 days. During this period, the bonded parts must not be affected by impact and vibration.

[0093] (6) Maintenance of concrete slab walls.

[0094] An interface glue is provided between the contact surface of the concrete slab wall 12 and the existing abutment 4, and an anchor bar 41 is provided on the existing abutment 4. The anchor bar 41 extends into the concrete slab wall 12, so that the connection between the concrete slab wall 12 and the existing abutment 4 is more secure. The concrete slab wall 12 is provided between the existing cap beam 6 and the newly built pedestal 11. The concrete slab wall 12 is used to support the existing cap beam 6, so that the reconstructed bridge structure is more stable. The newly built pedestal 11, the existing abutment 4 and the new bored pile foundation 10 can be used as a new supporting structure, so that the bridge is more stably subjected to stress.

[0095] As the instruction manual Figure 8 As shown, after the construction of the new foundation is completed, the temporary beam and the temporary beam support are removed, the end point of the existing bridge is placed on the existing cap beam, concrete is poured on the stepped new slope to form a road-bridge transition zone 13, filled with C20 concrete to be aligned with the roadbed, and the pavement layer 14 is constructed above the road-bridge transition zone 13. After the backfill on both sides of the road and the construction of the crash barriers on both sides of the road are completed, the bridge traffic can be restored, and then the construction of the new railway line 15 is carried out under the existing bridge 2.

[0096] In summary, the present invention provides a method for bridge reconstruction, in which a new railway passes under an existing bridge, the existing abutment is reinforced and the existing side slope is sloped, new bored pile foundations are alternately set at the existing abutment foundation and a new cap is constructed, the new cap is connected to the existing abutment foundation, the new bored pile foundation and the existing abutment foundation are connected as a whole, and a concrete slab wall is set between the new cap and the existing cap beam and the original pile foundation is encapsulated, so that the existing cap beam can be evenly stressed. The new railway line is constructed without affecting the existing railway line, and there is no need to bypass the existing bridge or demolish the existing bridge, which can save costs and shorten the construction period.

[0097] Those skilled in the art will appreciate that the present invention can be implemented in many other specific forms without departing from the spirit and scope of the present invention. Although embodiments of the present invention have been described, it should be understood that the present invention should not be limited to this embodiment, and those skilled in the art can make changes and modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A method for bridge reconstruction, characterized in that: The steps include: S1: After constructing the temporary beam support point on the side close to the existing abutment, the temporary beam is used to support the existing bridge; S2: constructing the existing slope and forming a new slope by reducing the slope of the existing slope; constructing the existing slope under the existing bridge to form a roadbed, and building a new railway line on the roadbed; the new slope is in the shape of steps and extends to the bottom of the pavement layer structure; S3: construct a new bored pile foundation, and construct a new cap on the new bored pile foundation. The new cap is connected to the existing abutment foundation, and a concrete slab wall is set between the new cap and the existing cap beam. S4: Remove the temporary beam and its support points in S1; S5: pouring concrete on the newly built slope to form a road-bridge transition zone, and constructing the pavement layer above the road-bridge transition zone; S6: Construction of a new railway line under an existing bridge.

2. The method for bridge reconstruction according to claim 1, characterized in that: In the step S1, at least two temporary beam fulcrums are set, a temporary beam is set above the temporary beam fulcrum, and the temporary beam fulcrums at both ends of the temporary beam are located outside the existing bridge.

3. The bridge reconstruction method according to claim 1, characterized in that: In step S1, the construction steps of the temporary beam support point are as follows: after the construction of the cast-in-place piles at the lower end is completed, a temporary beam pier is constructed above the cast-in-place piles.

4. The method for bridge reconstruction according to claim 1, characterized in that: In the step S1, the temporary beam is a Bailey beam.

5. The bridge reconstruction method according to claim 1, characterized in that: In step S3, a plurality of the new bored pile foundations are constructed and arranged side by side along the existing abutment foundation, the new bored pile foundations and the existing abutment foundations are arranged alternately, and the newly built cap above the new bored pile foundation is located below the existing cap beam.

6. The bridge reconstruction method according to claim 5, characterized in that: The newly built abutment is sleeved on the existing abutment foundation so that the existing abutment foundation and the new bored pile foundation form a whole.

7. The bridge reconstruction method according to claim 1, characterized in that: In step S3, after the construction of the concrete slab wall is completed, the existing abutment is encapsulated with concrete.

8. The bridge reconstruction method according to claim 1, characterized in that: The concrete slab wall is a cast-in-place concrete part or a prefabricated concrete part.

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