A rapid pushing and translocation construction method for a frame bridge adjacent to an existing line

Abstract

The present application belongs to the technical field of bridge engineering construction, and particularly relates to a method for rapid pushing and transverse moving construction of a frame bridge adjacent to an existing line; after precasting of the frame bridge is completed, a top beam is placed centrally behind the initial jacking position of the frame bridge; anchor columns are installed on the left and right sides of the jacking area of the frame bridge, the anchor columns are implanted into the reserved holes of the pile caps, each side includes two anchor columns, and an anchor beam is placed in front of the anchor columns; the top beam is connected with the anchor beams on the two sides through the fine rolled threaded steel, the matching steel backing plate and the nut; the jacks are symmetrically arranged on the two sides of the bottom of the frame bridge with the slide center line as the axis; under the action of the reaction force of the top beam, the jacks push the frame bridge forward, after the frame bridge advances by one step, the jacks are restored by backhoes, the top beam moves forward and contacts with the jacks, the fine rolled threaded steel is fastened, and the cycle is repeated until the bridge body is in place; the method replaces the pushing back of the traditional construction method, the pushing reaction force is provided through the back beam, the system can be recycled and reused, and the engineering cost is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of bridge engineering construction technology, specifically relating to a rapid jacking and lateral movement construction method for a frame bridge adjacent to an existing railway line. Background Technology

[0002] With the rapid development of railway engineering, frame bridges, due to their unique advantages and special geographical environment, are increasingly being designed and implemented in new railway construction or the renovation of existing lines in urban areas. In the construction of new railway projects adjacent to existing lines, after the frame bridge is prefabricated in a horizontally parallel position, it is moved laterally to the designed location by jacking. Traditional jacking methods involve constructing a jacking backing structure outside the prefabricated frame bridge location to provide reaction force support. This backing structure is immovable and typically consists of concrete pile foundations and concrete retaining structures. The more frame bridges there are, the higher the construction cost of the jacking backing structure. Furthermore, many defense fiber optic cables and large water pipelines are generally shallowly buried underground within urban areas, and relocation work will cause serious delays in the construction period, or even make relocation impossible.

[0003] CN104612056B discloses a method for rapid jacking and lateral movement of a frame bridge, comprising the following steps: constructing a sliding plate on one side of the existing railway and constructing a jacking backing at the end of the sliding plate; prefabricating a frame bridge on the sliding plate, with the top of the frame bridge bottom plate basically flush with the existing railway shoulder; increasing the burial depth of pipelines on both sides of the jacking and lateral movement area of ​​the existing railway, with the burial depth deeper than the bottom of the frame bridge bottom plate; installing jacks at the rear end of the frame bridge, removing the existing railway track, and jacking and laterally moving the frame bridge; after the frame bridge is jacked and laterally moved to the original position of the removed existing railway, restoring the existing railway track in situ within the frame bridge.

[0004] The aforementioned patent can achieve the jacking and lateral movement of frame bridges, but it also has the following problems:

[0005] 1. The back of the jacking pile is fixed, and the structure is a bored pile, which cannot be recycled. In addition, the back of the bored pile is set with masonry, which results in a long construction period and high project cost.

[0006] 2. Due to the construction of a fixed jacking back structure, it is necessary to permanently or temporarily relocate or add protective steel sleeves or culverts to the above-ground and underground pipelines within the jacking range. Summary of the Invention

[0007] To address the problems encountered during the jacking and lateral movement of newly constructed railway frame bridges adjacent to busy existing lines, such as the immovable jacking backrest, high construction costs, long construction periods, and numerous interfering factors, this invention provides a rapid jacking and lateral movement construction method for multi-span continuous frame bridges adjacent to existing lines.

[0008] This invention is achieved using the following technical solution: a method for rapid jacking and lateral movement of a frame bridge adjacent to an existing railway line. After the frame bridge is prefabricated, a top beam is placed centered behind the initial jacking position of the frame bridge. Anchor columns are installed on both sides of the jacking area of ​​the frame bridge, and the anchor columns are inserted into the reserved holes in the concrete of the abutment. Each side includes two anchor columns, and an anchor beam is placed in front of the anchor columns, with both ends of the anchor beam resting on the anchor columns. The top beam is connected to the anchor beams on both sides through precision-rolled threaded steel bars and matching steel pads and nuts. The anchor columns and precision-rolled threaded steel bars on both sides of the frame bridge are symmetrical about the center line of the slide rail. Jacks are symmetrically arranged on both sides of the bottom of the frame bridge about the center line of the slide rail. With the help of the reaction force of the top beam, the jacks push the frame bridge forward. After the frame bridge advances one step, the jacks are returned to their original position, and the top beam moves forward to contact the jacks, tightening the precision-rolled threaded steel bars in preparation for the next jacking operation. This cycle is repeated until the bridge body is in place.

[0009] Furthermore, a rapid jacking and lateral movement construction method for a frame bridge adjacent to an existing railway line includes the following steps:

[0010] S1: Measure and lay out the lines, calculate the prefabrication position of the frame bridge. The prefabrication position of the frame bridge is offset laterally and parallel to the design position of the frame bridge; measure and lay out the anchor column position, and reserve the anchor column reserved holes when pouring the foundation concrete.

[0011] S2: Skateboard foundation treatment, the skateboard foundation uses Group B material for replacement and layered compaction;

[0012] S3: Construction of sliding plate and guide pier: A sliding plate is set between the prefabrication position and the design position of the frame bridge; a guide pier is set on both sides of the frame bridge in the direction of jacking between the sliding plate and the pier cap.

[0013] S4: Lubrication layer construction, a lubrication layer is installed on the top of the slide plate;

[0014] S5: Precast frame bridge;

[0015] S6: Install anchor columns, anchor beams, top beams, precision-rolled threaded steel bars, and jacks;

[0016] S7: Calculation of the top thrust of the frame bridge. The calculation formula is: P = μN; where: P is the maximum top force, μ is the friction coefficient between the sliding plate lubrication layer and the top load, and N is the weight of the frame bridge.

[0017] S8: Jacking and lateral movement construction;

[0018] S9: Remove anchor columns, anchor beams, top beams, precision-rolled threaded steel bars, and jacks;

[0019] S10: Remove the skateboard and restore the original surface.

[0020] Furthermore, the anchor beam is made of double-channel steel with steel plates attached and welded together; the top beam is made of a rear beam and a front beam welded together with steel plates. The rear beam is made of steel plates, two channel steels and one I-beam welded together, and the front beam is made of steel plates and three I-beam welded together. The top beam is connected to the anchor beam by four precision-rolled threaded steel bars, with two bars on each side, and double nuts are provided at all eight nut connection positions.

[0021] Furthermore, during the pouring of the pier cap concrete, four pre-reserved holes are arranged on the left and right sides of the frame bridge jack, located at 50cm and 102cm on both sides of the frame bridge respectively; the anchor column is 1m high and is inserted into the pre-reserved hole of the pier cap concrete 0.5m deep.

[0022] Furthermore, the sliding plate is a reinforced concrete structure, and the flatness of the sliding plate is controlled within 3mm. The bottom plate at the front end of the frame bridge is provided with a bow slope, and the sliding plate surface is provided with a 0.3% upward slope along the jacking direction, with the front higher than the back. The guide piers are pre-embedded when the sliding plate and its abutment are poured.

[0023] Furthermore, the lubricating layer includes a paraffin layer, talc powder, and a plastic film;

[0024] Place iron wires horizontally on the skateboard at 1m / track intervals. Heat the paraffin wax to 150℃, then add 25% machine oil and stir well. Pour the paraffin wax and machine oil mixture between the two iron wires on the skateboard, smooth the surface, and use a blowtorch to seal the grooves left after removing the iron wires. Sprinkle talcum powder on the poured paraffin wax surface. Then lay a layer of plastic film on top of the talcum powder.

[0025] A layer of cement mortar, 2-3 cm thick, is laid on the plastic film at the prefabrication location of the frame bridge to prevent damage to the plastic film during the prefabrication process. The cement mortar is laid 50 cm beyond the frame bridge.

[0026] Furthermore, a steel plate trailer is installed at the contact point between the jack and the frame bridge.

[0027] Furthermore, during step S8, the centerline, plan, elevation, and other features of the frame bridge are monitored, and timely adjustments and corrections are made. The correction method is to adjust the distribution valve and use unequal pressure to generate a correction torque for correction.

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] Replacing the traditional jacking method with a backrest, the jacking reaction force is provided by the backrest beam. The jacking system is reusable, significantly reducing project costs. By using jacks to successively push and move the jacking beam forward, the costly fixed jacking backrest structure of traditional methods is replaced, and no jacking iron is needed, enabling rapid jacking and lateral movement of the frame bridge. Except for the jacks, the jacking system is fabricated using readily available, simple, and inexpensive on-site materials. The absence of jacking iron ensures stable force distribution, and the ease of assembly, disassembly, and construction significantly shortens the construction period and reduces project costs. Furthermore, the elimination of the need to relocate underground pipelines and conduits further shortens the construction period and reduces costs. Attached Figure Description

[0030] Figure 1 Top view of a frame bridge undergoing rapid jacking and lateral movement;

[0031] Figure 2 Side view of a frame bridge undergoing rapid jacking and lateral movement;

[0032] Figure 3 Here is a structural diagram of the anchor post;

[0033] Figure 4 This is a structural diagram of the end face of the anchor beam;

[0034] Figure 5 for Figure 4 AA view;

[0035] Figure 6 for Figure 4 BB view;

[0036] Figure 7 This is a structural diagram of the end face of the top beam;

[0037] Figure 8 for Figure 7 AA view;

[0038] Figure 9 for Figure 7 BB view;

[0039] In the diagram: 1-Anchor column; 2-Anchor beam; 3-Top beam; 4-Precision rolled threaded steel bar; 5-Jack; 6-Steel plate cascade; 7-Slide plate; 8-Pile cap; 9-Guide pier; 10-Pile foundation; 11-Steel plate; 12-Channel steel; 13-Pre-reserved hole for precision rolled threaded steel bar; 14-I-beam; X-Centerline of slide rail; Y-Design centerline; P1-Pre-position of frame bridge (before jacking); P2-Design position of frame bridge (after jacking). Detailed Implementation

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] like Figure 1 , Figure 2 The diagram illustrates a rapid jacking and lateral movement construction method for a frame bridge adjacent to an existing railway line. After the frame bridge is prefabricated, a top beam 3 is placed centered behind the initial jacking position. Anchor columns 1 are installed on both sides of the jacking area of ​​the frame bridge, with each anchor column 1 embedded in a pre-drilled hole in the concrete abutment. Each side includes two anchor columns 1. Anchor beams 2 are placed in front of the anchor columns 1, with both ends of the anchor beams 2 resting on the anchor columns 1. The top beam 3 is connected to the anchor beams 2 on both sides via precision-rolled threaded steel bars 4 and matching steel pads and nuts. The anchor columns 1 and precision-rolled threaded steel bars 4 on both sides of the frame bridge are symmetrical about the centerline of the slide rail. Jacks 5 are symmetrically arranged on both sides of the bottom of the frame bridge about the centerline of the slide rail. With the help of the reaction force of the top beam 3, the jacks 5 push the frame bridge forward. After the frame bridge advances one step, the jacks 5 are returned to their original position, and the top beam 3 moves forward to contact the jacks 5, tightening the precision-rolled threaded steel bars 4, ready for the next jacking operation. This cycle is repeated until the bridge body is in place.

[0042] A rapid jacking and lateral movement construction method for a frame bridge adjacent to an existing railway line specifically includes the following steps:

[0043] 1. Surveying and Setting Out: While ensuring the construction does not encroach on the existing railway line's safety clearance, calculate the prefabrication location of the frame bridge, offset laterally by 3.5m. For single-span frame bridges, the distance from the existing railway line to the prefabrication location on the side closest to the line is set at 12m. Mark out the prefabrication location of the frame bridge, the centerline of the sliding track, and the edge lines. Survey and set out the anchor column locations, reserving anchor column holes during the foundation concrete pouring.

[0044] 2. Skateboard foundation treatment: The skateboard foundation is replaced with Group B material. The excavation depth of the foundation pit is 150cm, the length is 8.85 (13.45)m, and the width is 5.5m. 130cm of Group B material is compacted in the foundation pit. Vibratory roller is used to compact the material in layers and the compaction degree is controlled according to the design requirements.

[0045] 3. Construction of sliding plate and guide pier: Sliding plate is set along the jacking line, that is, a sliding plate is set between the prefabrication position and the design position of the frame bridge.

[0046] The sliding plate is a reinforced concrete structure, reinforced with HRBφ16mm steel bars spaced 15cm apart. The concrete is C30. It measures 8.85 (13.45)m in length, 5m in width, and 20cm in thickness. The flatness of the sliding plate is controlled within 3mm. Before jacking, a 3mm thick layer of paraffin wax (mixed with 25% machine oil) is evenly applied to the surface, followed by a 1mm thick layer of talcum powder, and then a layer of plastic film. To prevent the sliding plate from buckling during jacking, a bow slope is set at the front end of the frame bridge's bottom plate, and the sliding plate surface has a 0.3% slope (higher at the front and lower at the back) along the jacking direction.

[0047] A guide pier is installed on both sides of the frame bridge at a distance of 2.0m between the slide plate and the pier cap in the direction of jacking to prevent the slide plate from sliding when the frame bridge is jacked up. The guide pier is a 50*50*50cm C20 reinforced concrete structure and is pre-embedded when the slide plate and its pier cap are poured.

[0048] The above three steps can be carried out in stages, with each stage involving the measurement and layout of 3 to 10 spans of the frame bridge, the construction of the sliding plate layer and the sliding plate.

[0049] 4. Lubrication layer construction: A lubrication layer is installed on the top of the skateboard, which includes a paraffin layer, talcum powder and plastic film.

[0050] Place No. 10 iron wires horizontally on the skateboard at 1m / lane intervals. Heat paraffin wax to about 150℃, then mix in 25% machine oil (reduce the oil ratio if the temperature is high). After stirring evenly, spray the mixture between two No. 10 iron wires on the skateboard using a flat-nozzle spray bottle, to a thickness of about 3mm. Immediately smooth it with a wooden scraper. Use a blowtorch to seal the grooves left after removing the iron wires. Sprinkle talcum powder on the paraffin wax surface, to a thickness of about 1mm. Then lay a layer of plastic film on top of the talcum powder. To ensure the plastic film layer is a single unit, use 50mm wide plastic adhesive tape to seal the seams of the plastic film to prevent misalignment during overlap.

[0051] A layer of M10 cement mortar, 2-3 cm thick, is laid on the plastic film at the prefabrication location of the frame bridge to prevent damage to the plastic film during the prefabrication process. The cement mortar is laid 50 cm beyond the frame bridge.

[0052] Precast frame bridge: After the cement mortar has solidified, the reinforcing bars are tied according to the design documents, and the formwork and supports are installed. Concrete is then poured to complete the precasting of the single-span frame bridge. Once the frame concrete meets the design requirements, the formwork and scaffolding are removed, and site debris is cleared. Only after the frame concrete meets the design requirements can the jacking operation begin.

[0053] 6. Backbeam System Installation: The frame bridge uses a circulating backbeam system, consisting of anchor columns, anchor beams, precision-rolled threaded steel bars, a top beam, and jacks. During the concrete pouring of the pier cap, φ132mm anchor column holes are pre-drilled, each 50cm deep. Four anchor column holes are installed on both sides of a single frame bridge during jacking, located at 50cm and 102cm positions on each side of the bridge. The holes are symmetrically and straightly laid out with accurate positioning. The anchor columns are made of φ130mm 40# steel bars, 1m high, and inserted 0.5m into the pre-drilled holes in the pier cap concrete. The anchor columns are installed in the pre-drilled holes, and an anchor beam is placed in front of two anchor columns. The anchor beam is constructed by welding double-splitting 25b channel steel with an outer steel plate. The top beam 3 is composed of a rear end beam and a front end beam welded together from steel plates. The rear end beam is welded from 20mm thick steel plates, two 40#b channel steels, and one I40# I-beam, while the front end beam is welded from steel plates and three I32# I-beams. The top beam is placed centered behind the initial jacking position of the frame bridge. The top beam is connected to the anchor beam by four PSB830φ32mm precision-rolled threaded steel bars, matching steel pads, and nuts. Two bars are installed on each side, and double nuts are installed at all eight nut connection points.

[0054] 7. Installation and commissioning of the jacking equipment:

[0055] During the jacking of the frame bridge, the jacking force mainly comes from the frictional resistance between the bottom of the frame bridge and the sliding lubrication layer. The simplified calculation formula is: P = μN; where: P is the maximum jacking force (kN), μ is the friction coefficient between the sliding lubrication layer and the top load, and N is the weight of the frame. The construction sliding friction coefficient was determined to be 0.3336 and the starting friction coefficient to be 0.7548 through reverse jacking tests. The frames are divided into two types: 6.85m and 11.45m (including 13.75m). The smaller frame requires a maximum jacking force of 678.872kN, and this frame bridge is equipped with two 2000kN jacks, 2*2000kN = 4000kN > 678.872kN. The larger frame requires a maximum jacking force of 2002.512kN, and this frame bridge is equipped with four 2000kN jacks, 4*2000kN = 8000kN > 2002.512kN.

[0056] Depending on the frame type, jacks are symmetrically arranged on both sides of the bottom of the frame, with the center line of the slide as the axis. A 20mm thick steel plate support is installed at the contact point between one end of the jack and the frame to increase the contact area between the jack and the frame concrete, while preventing the jack from contacting the base plate and causing scraping. The other end of the jack rests on the top beam. Install and connect the oil pump, oil tank, oil pipeline, and other auxiliary equipment according to the jack's instruction manual.

[0057] After the entire hydraulic system is installed, it is inspected and tested.

[0058] 8. Jacking and lateral movement construction:

[0059] The high-pressure oil pump is activated to generate jacking force. Through the force transmission device, and with the help of the reaction force of the jacking beam, the bridge body is propelled forward. After the bridge body has moved forward, the pick is returned to its original position, and the jacking beam moves forward to contact the jacks, tightening the precision-rolled threaded steel bars, ready for the next pick operation. This cycle is repeated until the bridge body is in place.

[0060] During the jacking and lateral movement process, the centerline, plan, elevation, and other features of the frame bridge are monitored, and timely adjustments and corrections are made. The correction method is to adjust the distribution valve and, with the jacks arranged symmetrically, use unequal pressure to generate a correction torque for correction.

[0061] 9. Rear Backbeam System Removal: After the frame is jacked up, the rear backbeam system is removed and transported to the next frame jacking location for reuse.

[0062] 10. Removal of the skateboard: Remove the concrete and gravel subbase of the skateboard and restore the original surface according to the design documents.

[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for rapid pushing and translocation construction of a frame bridge adjacent to an existing line, characterized in that: The frame bridge is pre-fabricated, and a top beam is placed in the middle behind the initial jacking position of the frame bridge after pre-fabrication; anchor columns are installed on the left and right sides of the jacking area of the frame bridge, and the anchor columns are implanted into the reserved holes of the bearing platform concrete, each side including two anchor columns; an anchor beam is placed in front of the anchor columns, and the two ends of the anchor beam are supported on the anchor columns; the top beam is connected with the anchor beams on the two sides through the fine rolled threaded steel and the matching steel backing plate and nut; the anchor columns and the fine rolled threaded steel on the two sides of the frame bridge are symmetrical about the center line of the slide; the jacks on the two sides of the bottom of the frame bridge are arranged symmetrically about the center line of the slide; the frame bridge is pushed forward by the jacks with the help of the reaction force of the top beam, and after the frame bridge advances by one step, the jacks are restored by backhoeing, the top beam moves forward and contacts with the jacks, the fine rolled threaded steel is fastened, and the next time the jacks are hoed, and the cycle is repeated until the bridge body is in place.

2. The method according to claim 1, characterized in that, The method comprises the following steps: S1: measuring the wire, calculating the frame bridge pre-fabrication position, the frame bridge pre-fabrication position is the frame bridge design position offset horizontally and outwardly; measuring and lofting the anchor column position, and reserving the anchor column reserved hole when pouring the bearing platform concrete; S2: slide plate foundation treatment, the slide plate foundation is replaced by B group material, and is compacted in layers; S3: slide plate and guide pier construction, a slide plate is arranged between the frame bridge pre-fabrication position and the design position; a guide pier is arranged between the slide plate and the bearing platform on the two sides of the frame bridge in the jacking direction; S4: lubricating layer construction, a lubricating layer is arranged on the top of the slide plate; S5: frame bridge pre-fabrication; S6: installation of anchor column, anchor beam, top beam, fine rolled threaded steel and jack; S7: frame bridge jacking force calculation, the calculation formula is: P = μN; in the formula, P is the maximum jacking force, μ is the friction coefficient of the lubricating layer of the slide plate and the top load, and N is the weight of the frame bridge; S8: jacking and translocation construction; S9: removal of anchor column, anchor beam, top beam, fine rolled threaded steel and jack; S10: slide plate removal, and restoration of the original ground surface.

3. The method according to claim 1, characterized in that: The anchor beam is composed of double-spliced channel steel and externally-pasted steel plate and is welded; the top beam is composed of a rear end beam and a front end beam and is welded by steel plates; the rear end beam is welded by steel plates, two channel steels and one I-beam; the front end beam is welded by steel plates and three I-beams; the top beam is connected with the anchor beams by four fine rolled threaded steels, two on each side, and double nuts are arranged at eight nut connection positions.

4. The method according to claim 2, characterized in that: When the bearing platform concrete is poured, four reserved holes are arranged on the left and right sides of the frame bridge, and are located at positions 50 cm and 102 cm from the two sides of the frame bridge respectively; the anchor column is 1 m high and is implanted into the bearing platform concrete reserved hole by 0.5 m.

5. The method according to claim 2, wherein the method is characterized in that: The slide plate is a reinforced concrete structure, the flatness of the slide plate is controlled to be within 3 mm, a bow slope is arranged on the bottom plate of the front end of the frame bridge, and a 0.3% upward slope that is high in front and low in back is arranged on the slide plate surface in the jacking direction; the guide pier is pre-buried when the slide plate and the bearing platform thereof are poured.

6. The method according to claim 2, wherein the method is characterized in that: The lubricating layer comprises a paraffin layer, talcum powder and a plastic film; Iron wires are horizontally placed on the slide plate at an interval of 1 m, paraffin is heated to 150 DEG C, 25% machine oil is added, the mixture is stirred uniformly, the paraffin and machine oil mixture is poured between the two iron wires on the slide plate, the surface is scraped flat, the groove mark after the iron wires are pulled out is baked with a blowtorch, talcum powder is sprinkled on the poured paraffin surface, and a layer of plastic film is laid on the talcum powder; A layer of cement mortar with a thickness of 2-3 cm is laid on the plastic film at the prefabrication position of the frame bridge to prevent the plastic film from being damaged during the prefabrication of the frame bridge, and the range of the cement mortar is 50 cm larger than that of the frame bridge.

7. The method according to claim 2, wherein the method is characterized in that: A steel plate trailer is arranged at the contact position of the jack and the frame bridge.

8. The method according to claim 2, characterized in that: During the pushing and transverse moving process of step S8, the central axis, plane and elevation of the frame bridge are monitored, and timely adjustment and deviation correction are performed. The deviation correction is performed by adjusting the distribution valve to form a deviation correction torque in an unequal pressure mode.

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