Construction Method for Bridge Splicing System in Highway Reconstruction and Expansion

Abstract

This application relates to a construction method for the splicing system of highway reconstruction and expansion bridges. The scheme includes (1) construction preparation; (2) pier column and capping beam construction; (3) jacking and replacing the bearings of the original bridge T-beams; (4) drilling and implanting steel bars in the original bridge T-beams; (5) installing the tension bracing system for the T-beam webs; (6) cutting and chiseling the original bridge deck paving concrete; (7) hoisting the integral steel cage of the diaphragm; (8) installing the diaphragm formwork system; (9) integrally pouring the diaphragm and the wet joint; (10) pouring the compensated shrinkage concrete. This application ensures the stability of the original bridge lift, enhances the connection between the original bridge and the widened bridge, has good diaphragm pouring quality, and there is no cracking phenomenon on the surface layer of the wet joint, achieving good technical and economic benefits.

Description

Technical Field

[0001] This application relates to the technical field of civil engineering, and is mainly applicable to the widening and strengthening of existing highway bridges, especially applicable to the construction of bridge reconstruction, expansion and widening splicing, and specifically relates to the construction method of the highway reconstruction and expansion bridge splicing system. Background Art

[0002] In recent years, with the rapid development of China's economy and the frequent flow of personnel and materials, the traffic volume of some existing expressways has tended to be saturated, and the service level has declined severely, making it difficult to meet the development requirements of social economy and the travel needs of people. There is an urgent need for upgrading, widening and reconstruction. In the expressway reconstruction and expansion project, it is necessary to widen both sides or one side of the original highway. Moreover, with the continuous improvement of the bridge load standard level, various problems such as the reconstruction, reinforcement and widening of bridges on the original highway are involved. The design of the expressway reconstruction and expansion project mainly focuses on straight bridges, diagonal bridges and variable-width bridges in the main line or interchange hub areas. The connection between the widened bridge and the existing old bridge is the key factor for the success or failure of bridge splicing. Due to the restriction of existing engineering technologies, the reconstruction of the original old bridge often can only adopt the method of demolition and reconstruction or partial reconstruction. However, this kind of reconstruction method increases the investment scale and cannot guarantee the normal traffic of the bridge during the implementation process. Compared with demolishing the old bridge and rebuilding a new bridge, widening and splicing bridges has the advantages of effectively controlling the project cost, coordinating the aesthetics of new and old bridges and ensuring the safe and unobstructed highway, so it has become the only choice for expressway reconstruction and expansion projects.

[0003] However, there are still some problems in the process of highway reconstruction and expansion bridge splicing: (1) After the bridge is widened, the height of the original bridge does not meet the requirements, and it is necessary to further lift and raise the whole. When replacing the bearing during the lifting and raising, there is a lack of safe and stable temporary support; (2) During the widening splicing of new and old T-beams and the pouring of diaphragms, the widened T-beams are prone to lateral displacement, and there is a lack of strong connection measures between the webs of new and old T-beams; (3) The effective connection between the diaphragm steel cages and the wet joint steels between new and old T-beams is poor, and the integrity is not strong; (4) It is difficult to form the formwork of the diaphragm formwork system, and there is a lack of effective supporting surface. The diaphragm concrete and the wet joint concrete cannot be effectively integrated, and it is easy to form a fault; (5) The surface layer concrete of the wet joint is prone to shrinkage cracks, resulting in cracking at the splicing place.

[0004] Therefore, there is an urgent need for a construction method for the highway reconstruction and expansion bridge splicing system to solve the problems existing in the prior art.

[0005] Content of the Application

[0006] The purpose of this application is to provide a construction method for the highway reconstruction and expansion bridge splicing system for the above problems existing in the prior art.

[0007] To achieve the above application purpose, the present application adopts the following technical solutions: The construction method of the highway reconstruction and expansion bridge splicing system includes the following construction steps:

[0008] S1. Construction preparation: Before the formal construction, prepare a special construction plan in accordance with the requirements for construction on the operating line.

[0009] S2. Pier column and capping beam construction: Construct the widened pier columns at the designed positions, and erect the widened bridge capping beams on the upper parts of the widened pier columns.

[0010] Detect whether the edges of the widened bridge capping beam and the original bridge capping beam are aligned. Install the lower steel section and the upper steel section between the widened bridge capping beam and the original bridge capping beam through chemical adhesive anchors, and weld angle steels between the lower steel section and the upper steel section to connect the widened bridge capping beam and the original bridge capping beam into a whole.

[0011] Install widened T-beams on the widened bridge capping beam. The dimensions of the widened T-beams are the same as those of the original bridge T-beams. The bottom bearings of the widened T-beams adopt new T-beam bearings according to the designed elevation.

[0012] S3. Jacking up and replacing the bearings of the original bridge T-beams: Symmetrically install jacks under the lower parts of the webs of all the original bridge T-beams and conduct a trial jacking.

[0013] After the trial jacking is completed, install stepped temporary supports.

[0014] Lower the jacks to place the webs of the original bridge T-beams on the stepped temporary supports.

[0015] Remove the original T-beam bearings, reinstall the bearing pads, install new and heightened T-beam bearings on the bearing pads, raise the jacks, and remove the stepped temporary supports.

[0016] Then slowly lower the jacks to place the webs of the original bridge T-beams on the new T-beam bearings, paste them with epoxy resin, and detect whether the elevations of the tops of the ribs of the original bridge T-beams and the widened T-beams are the same.

[0017] S4. Drilling and implanting steel bars in the original bridge T-beams: Use a steel bar detector to detect the positions and embedment depths of the steel bars in the ribs of the original bridge T-beams, drill holes with an impact drill, and avoid hitting the structural steel bars.

[0018] After cleaning the residues in the holes, use a special injector or syringe to inject adhesive into the holes. Immediately after injecting the adhesive, insert the rib-implanted steel bars into the ribs by rotating them unidirectionally until the designed depth is reached.

[0019] After the rib-implanted steel bars are completely cured, weld them to the rib-embedded steel bars preset in the ribs of the widened T-beams, and longitudinally weld the longitudinal wet joint bars along the wet joint, and at the same time, evenly spacedly drill threaded holes and transverse diaphragm transverse bar reserved holes on the webs of the original bridge T-beams.

[0020] S5. Installation of the T-beam web tension bracing system: Pass the two ends of the high-strength threaded steel bars through the threaded holes on the web of the widened T-beam and the web of the original bridge T-beam respectively, and fix them with anchor fittings.

[0021] When applying tensile force to the high-strength threaded steel bars, set channel steels on both sides of the high-strength threaded steel bars between the web of the widened T-beam and the web of the original bridge T-beam, and wedge bearing steel plates on both sides of the channel steels to prevent the web of the T-beam from being deformed by force.

[0022] S6. Cutting and chiseling the paving concrete of the original bridge deck: Lay out the positioning line of the cutting keyway of the original bridge cast-in-place bridge deck according to the designed width, and use a cutting machine to cut to a depth of 10 mm.

[0023] Use a pneumatic pick or the like to chisel the bridge deck concrete paving layer of the cutting keyway of the original bridge cast-in-place bridge deck. The exposed original bridge cast-in-place bridge deck is fully roughened, and the convexity and concavity are less than 6 mm.

[0024] Insert shear key steel bars, fully flush them, then lay the steel mesh of the cast-in-place bridge deck, and weld the steel mesh of the cast-in-place bridge deck to the shear key steel bars.

[0025] S7. Hoisting the integral steel cage of the diaphragm wall: Hoist the integral steel cage of the diaphragm wall that has been pre-tied to the designed position.

[0026] Insert the lower transverse ribs of the integral steel cage of the diaphragm wall into the reserved holes of the transverse ribs of the diaphragm walls on both sides of the T-beam webs. The upper part is suspended by L-shaped hanging bars at the edge of the T-beam rib plate, and is welded to the steel mesh of the cast-in-place bridge deck, the embedded ribs of the rib plate, and the implanted ribs of the rib plate.

[0027] S8. Installing the formwork system of the diaphragm wall: Drive high-strength bolts at the designed positions on the webs of the widened T-beam and the original bridge T-beam to fix the supporting angle steels, and place the standardized L-shaped formwork with a grooved bottom plate on the supporting angle steels.

[0028] The left side and the right side of the vertical plate of the standardized L-shaped formwork are tightly abutted against the web of the original bridge T-beam and the web of the widened T-beam respectively.

[0029] The integral steel cage of the diaphragm wall is located 20 mm above the grooved bottom plate of the standardized L-shaped formwork. Insert the standardized insertable vertical plate into the card slot of the grooved bottom plate of the standardized L-shaped formwork to form an uncovered "box", and place the integral steel cage of the diaphragm wall in the box.

[0030] S9. Integral pouring of the diaphragm wall and the wet joint: Pour concrete into the wet joint, and integrally pour the concrete of the diaphragm wall and the wet joint to form a whole.

[0031] S10. Pour compensating shrinkage concrete: After the strength of the diaphragm and the wet joint concrete reaches the design requirements, pour compensating shrinkage concrete between the keyways cut on the cast-in-place bridge deck of the original bridge and the keyways of the widened cast-in-place bridge deck.

[0032] Finally, construct the bridge deck pavement layer and resume bridge traffic.

[0033] Further, in step S4, a wet joint is formed between the widened T-beam rib plate and the rib plate of the original bridge T-beam.

[0034] Further, in step S5, threaded holes are drilled in the webs of the original bridge T-beams, and threaded holes are also preset in the webs of the widened T-beams. The widened T-beam webs and the webs of the original bridge T-beams are tensioned by passing high-strength threaded steel bars through them.

[0035] Further, in step S7, diaphragms are evenly spaced between the original bridge T-beams and the widened T-beams. The diaphragms adopt integral steel reinforcement cages for diaphragms. Transverse rib reserved holes for diaphragms are drilled in the webs of the original bridge T-beams, and transverse rib reserved holes for diaphragms are also preset in the webs of the widened T-beams.

[0036] Further, in step S8, the diaphragm formwork system includes a standardized L-shaped formwork vertical plate, a standardized L-shaped formwork grooved bottom plate, and a standardized inserted vertical plate. The standardized L-shaped formwork vertical plate and the standardized L-shaped formwork grooved bottom plate are an integral structure.

[0037] Further, in step S3, jacks are symmetrically arranged on both sides at the bottom of the webs of the original bridge T-beams. Step-shaped temporary supports are arranged outside the jacks. A bearing padstone is arranged under the T-beam bearing, and a leveling steel plate is arranged above the T-beam bearing.

[0038] Further, in step S3, check whether there is bearing disengagement. If there is bearing disengagement, it is necessary to re-lift the beam, fill the gap between the web of the original bridge T-beam and the new T-beam bearing with a thin leveling steel plate to ensure that the web of the original bridge T-beam is completely in close contact with the new T-beam bearing and the top elevations of the rib plates of the original bridge T-beams and the widened T-beams are kept level.

[0039] Further, in step S7, the integral steel reinforcement cage for the diaphragm includes transverse diaphragm ribs, vertical diaphragm ribs, L-shaped lifting ribs, and lifting rib connecting bars. The L-shaped lifting ribs are thickened "L" steel bars, and lifting rib connecting bars are arranged between adjacent L-shaped lifting ribs for strengthening connection.

[0040] Further, in step S8, the top of the "box" without a cover is a wet joint cavity.

[0041] Further, in step S3, after the trial lift is completed, the beam body is officially lifted synchronously according to the designed lifting height. After lifting to the designed elevation, over-lift about 10 cm and install step-shaped temporary supports.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] (1) After the original bridge T-beams of the present application are jacked up integrally, stepped temporary supports are used to support the replacement and heightening of the T-beam bearings. The temporary supports have good safety and stability, and the integral lifting and heightening of the original bridge T-beams are successfully realized.

[0044] (2) During the process of widening and splicing the new and old T-beams and casting the diaphragm plates, a tension bracing system is installed between the webs of the new and old T-beams, which enhances the integrity of the connection between the new and old T-beams and reduces the lateral displacement of the widened T-beams.

[0045] (3) The present application adopts an integral diaphragm steel cage. The transverse steel bars of the steel cage are inserted into the preset holes in the webs of the T-beams on both sides, and the upper part is suspended by L-shaped hanging bars at the edges of the T-beam rib plates, which enhances the effective connection between the diaphragm steel cage and the wet joint steel bars and has strong integrity.

[0046] (4) The present application adopts a standardized assembled diaphragm formwork system. The formwork system is supported on the T-beam webs through resting angles. The formwork system is simple to disassemble and assemble, and the diaphragm concrete and the wet joint concrete are cast integrally, with reliable quality.

[0047] (5) The wet joint surface layer of the present application adopts shrinkage-compensating concrete, which can effectively reduce the shrinkage cracking of the concrete and ensure the flatness and beauty of the bridge deck at the splicing part. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 is the overall structure diagram of the bridge splicing system for highway reconstruction and expansion of the present application;

[0049] Figure 2 is the structure diagram of the strengthened connection between the original bridge capping beam and the widened bridge capping beam of the present application;

[0050] Figure 3 is the detailed structure diagram of the jacking support and bearing replacement of the original bridge T-beam web of the present application;

[0051] Figure 4 is the structure diagram of the tension bracing system between the original bridge T-beam web and the widened bridge T-beam web of the present application;

[0052] Figure 5 is the structure diagram of the integral diaphragm steel cage of the present application;

[0053] Figure 6 is the overall drawing of the steel bar lapping at the wet joint of the original bridge T-beam and the widened bridge T-beam of the present application;

[0054] Figure 7 is the detailed structure diagram of the installation of the integral diaphragm steel cage of the present application;

[0055] Figure 8It is the installation position diagram of the tension bracing system for the T-beam web and the diaphragm formwork system in this application;

[0056] Figure 9 It is the detailed assembly structure diagram of the diaphragm formwork system in this application;

[0057] Figure 10 It is the front view of the diaphragm formwork system in this application;

[0058] Figure 11 It is the detailed installation structure diagram of the diaphragm formwork system and the integral steel cage in this application;

[0059] Figure 12 It is the process flow diagram of this application.

[0060] In the figure, 1. Original bridge pier column; 2. Widened bridge pier column; 3. Original bridge capping beam; 4. Widened bridge capping beam; 5. T-beam bearing; 6. Bearing pad stone; 7. Jack; 8. Lower steel section; 9. Upper steel section; 10. Chemical adhesive anchor bolt; 11. Angle steel; 12. Widened T-beam web; 13. Widened T-beam rib; 14. Original bridge T-beam web; 15. Original bridge T-beam rib; 16. Original bridge cast-in-place bridge deck; 17. Cut keyway of the original bridge cast-in-place bridge deck; 18. Keyway of the widened cast-in-place bridge deck; 19. Wet joint; 20. Leveling steel plate; 21. Step-shaped temporary support; 22. Reinforcement mesh of the cast-in-place bridge deck; 23. Embedded reinforcement of the rib; 24. Inserted reinforcement of the rib; 25. Longitudinal reinforcement of the wet joint; 26. Threaded hole; 27. Fine-threaded deformed steel bar; 28. Channel steel; 29. Load-bearing steel plate; 30. Anchor; 31. Transverse reinforcement of the diaphragm; 32. Vertical reinforcement of the diaphragm; 33. L-shaped suspender; 34. Connecting reinforcement of the suspender; 35. Reserved hole for the transverse reinforcement of the diaphragm; 36. Integral steel cage of the diaphragm; 37. Diaphragm formwork system; 38. High-strength bolt; 39. Resting angle steel; 40. Fixed L-shaped formwork vertical plate; 40-1. Left side of the vertical plate; 40-2. Right side of the vertical plate; 41. Fixed L-shaped formwork grooved bottom plate; 42. Fixed inserted vertical plate; 43. Card slot. Specific embodiments

[0061] Next, the technical solutions in the embodiments of this application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of this application.

[0062] Those skilled in the art should understand that in the disclosure of this application, the orientation or positional relationships indicated by terms such as "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing this application and simplifying the description, 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. Therefore, the above terms should not be construed as limiting this application.

[0063] Technical requirements for pier columns and capping beams, structure and construction technical requirements for chemical adhesive anchor bolts, unified jacking operation method, T-beam rib bar planting method, structure and tensioning principle of anchor fittings, technical requirements for steel cage binding, key points for formwork assembly operation, technical requirements for commercial concrete pouring, mix proportion of shrinkage-compensating concrete, concrete curing technology, welding technical requirements for each steel plate and steel bar, etc. are not elaborated in this application again. The implementation modes of the structures involved in this application are mainly described.

[0064] As Figure 12 shown, the construction method of the highway reconstruction and expansion bridge splicing system includes the following steps:

[0065] S1. Construction preparation: Before formal construction, in accordance with the requirements for construction on the existing railway line, prepare a special construction plan, take road closure measures, conduct a trial run of the jacks 7 to ensure that the constant speed of each jacking force is basically the same, install a guardrail device around the site, remove the anti-collision guardrail set on the original bridge, remove the bridge deck within 0.5 m of the inner edge of the original bridge, and arrange the steel structure on the outside.

[0066] S2. Pier column and capping beam construction: Construct the widened pier column 2 at the designed position, erect the widened bridge capping beam 4 on the upper part of the widened pier column 2, and check whether the edges of the widened bridge capping beam 4 and the original bridge capping beam 3 are aligned;

[0067] Install the lower steel shape 8 and the upper steel shape 9 between the widened bridge capping beam 4 and the original bridge capping beam 3 through chemical adhesive anchor bolts 10, and weld angle steel 11 between the lower steel shape 8 and the upper steel shape 9 to connect the widened bridge capping beam 4 and the original bridge capping beam 3 into a whole;

[0068] Install widened T-beams on the widened bridge capping beam 4. The dimensions of the widened T-beams are the same as those of the original bridge T-beams, and the bottom bearings adopt new T-beam bearings 5 according to the designed elevation;

[0069] S3. Jacking and replacing the bearings of the original bridge T-beams: Symmetrically install jacks 7 under the lower parts of the webs 14 of all the original bridge T-beams and conduct a trial jacking. The trial jacking height is controlled at about 5 mm;

[0070] After the trial jacking is completed, synchronously and formally jack up the beam body to the designed jacking height. After reaching the designed elevation, over-jack by about 10 cm and install the stepped temporary support 21;

[0071] The lowering jack 7 places the original bridge T-beam web 14 on the stepped temporary support 21;

[0072] Remove the original T-beam bearing 5, reinstall the bearing pad stone 6, install the new and heightened T-beam bearing 5 on the bearing pad stone 6, raise the jack 7, and remove the stepped temporary support 21;

[0073] Then slowly lower the jack 7, place the original bridge T-beam web 14 on the new T-beam bearing 5, and paste it with epoxy resin;

[0074] Detect whether the elevations of the tops of the ribs 15 of the original bridge T-beam and the tops of the ribs 13 of the widened T-beam are the same, and check whether there is bearing voiding. If there is bearing voiding, it is necessary to re-lift, fill the gap between the original bridge T-beam web 14 and the new T-beam bearing 5 with thin leveling steel plates 20, and ensure that the original bridge T-beam web 14 is completely in close contact with the new T-beam bearing 5 and the elevations of the tops of the ribs 15 of the original bridge T-beam and the tops of the ribs 13 of the widened T-beam are flush;

[0075] S4. Drilling and implanting steel bars in the original bridge T-beam: Use a steel bar detector to detect the position and embedment depth of the steel bars in the ribs 15 of the original bridge T-beam, and use an impact drill to drill holes, avoiding hitting the structural steel bars;

[0076] After cleaning the residue in the holes, use a special injector or syringe to inject adhesive into the holes. The injection volume is generally 2 / 3 of the hole depth. After injecting the adhesive, immediately insert the rib implanting steel bar 24 into the rib by rotating it unidirectionally until the designed depth is reached;

[0077] After the rib implanting steel bar 24 is completely cured, weld it to the rib embedded steel bar 23 preset in the rib 13 of the widened T-beam, and longitudinally weld the wet joint longitudinal steel bars 25 along the wet joint 19. At the same time, evenly spaced threaded holes 26 and transverse diaphragm transverse steel bar reserved holes 35 are drilled on the original bridge T-beam web 14;

[0078] S5. Installation of the T-beam web tensioning bracing system: Pass both ends of the high-strength threaded steel bar 27 through the threaded holes 26 on the widened T-beam web 12 and the original bridge T-beam web 14 respectively, and fix them with the anchor 30;

[0079] When applying tensile force to the high-strength threaded steel bar 27, channel steels 28 are arranged on both sides of the high-strength threaded steel bar 27 between the widened T-beam web 12 and the original bridge T-beam web 14, and bearing steel plates 29 are wedged on both sides of the channel steels 28 to prevent the T-beam web from deforming under force;

[0080] S6. Cutting and chiseling the original bridge deck paving concrete: According to the designed width, lay out the positioning line of the cutting keyway 17 of the original bridge cast-in-place bridge deck, and use a cutting machine to cut to a depth of 10 mm, paying attention not to cut the bridge deck steel bars;

[0081] Use a pneumatic pick to remove the original bridge cast-in-place bridge deck and cut the bridge deck concrete pavement layer of the tongue and groove 17. The exposed original bridge cast-in-place bridge deck must be fully roughened and have a certain degree of convexity and concavity, generally not less than 6mm;

[0082] The shear key reinforcement is implanted, and after being fully flushed, the cast-in-place bridge deck reinforcement mesh 22 is laid, and the cast-in-place bridge deck reinforcement mesh 22 is welded to the shear key reinforcement.

[0083] S7, hoisting the diaphragm integral steel cage 36: hoisting the diaphragm integral steel cage 36 tied in advance to the designed position, inserting the lower diaphragm transverse reinforcement 31 of the diaphragm integral steel cage 36 into the T-beam web diaphragm transverse reinforcement reserved holes 35 on both sides;

[0084] The upper part is hung on the edge of the T-beam rib plate by L-shaped hanger bars 33, and is welded to the cast-in-place bridge deck steel mesh 22, rib plate embedded bars 23, and rib plate embedded bars 24;

[0085] S8. Install the diaphragm formwork system 37: Install high-strength bolts 38 on the widened T-beam web 12 and the original bridge T-beam web 14 according to the designed position to fix the angle steel 39, and place the finalized L-shaped formwork grooved bottom plate 41 on the angle steel 39;

[0086] The left side 40-1 and the right side 40-2 of the vertical plate 40 of the standardized L-shaped formwork are respectively pressed against the original bridge T-beam web 14 and the widened T-beam web 12, and the diaphragm integral steel cage 36 is located at the thickness of the steel protection layer at a height of 20mm above the bottom plate 41 of the standardized L-shaped formwork groove;

[0087] Insert the standardized insert type vertical plate 42 into the slot 43 of the standardized L-shaped template grooved bottom plate 41 to form an uncovered "box" in which the diaphragm integral steel cage 36 is placed;

[0088] S9, integrated pouring of the diaphragm and the wet joint: pouring concrete into the wet joint 19, and integrally pouring the diaphragm and the wet joint concrete to form a whole. During the concrete pouring process, pay attention to vibrating and compacting;

[0089] S10, pouring additional shrinkage concrete: after the concrete strength of the diaphragm and the wet joint 19 reaches the design requirement, additional shrinkage concrete is poured between the cut tongue 17 of the original cast-in-place bridge deck and the tongue 18 of the widened cast-in-place bridge deck;

[0090] Finally, the bridge deck pavement layer was constructed to restore bridge traffic.

[0091] In this embodiment, if Figure 2The structural diagram of the strengthened connection between the original bridge capping beam and the widened bridge capping beam is shown, including the original pier column 1, widened pier column 2, original bridge capping beam 3, widened bridge capping beam 4, lower steel section 8, upper steel section 9, chemical adhesive anchor bolts 10, angle steel 11, etc. The widened pier column 2 is constructed on the right side of the original pier column 1 at the designed position. The widened bridge capping beam 4 is erected on top of the widened pier column 2. The original bridge capping beam 3 and the widened bridge capping beam 4 are clamped by arranging the lower steel section 8 and the upper steel section 9. Both the lower steel section 8 and the upper steel section 9 are connected to the capping beam through chemical adhesive anchor bolts 10. Angle steel 11 is welded between the lower steel section 8 and the upper steel section 9 to strengthen the overall connection; the connection integrity of the original bridge capping beam 3 and the widened bridge capping beam 4 is enhanced through the upper and lower steel sections.

[0092] As Figure 1 、 3 The overall structural diagram of the splicing system of the highway reconstruction and expansion bridge is shown, including the original pier column 1, widened pier column 2, original bridge capping beam 3, widened bridge capping beam 4, T-beam bearing 5, bearing pad stone 6, jack 7, widened T-beam web 12, original bridge T-beam web 14, leveling steel plate 20, stepped temporary support 21, etc. The original bridge T-beam needs to be integrally heightened and assembled with the widened T-beam. Jacks 7 are symmetrically arranged on both sides at the bottom of the original bridge T-beam web 14. Stepped temporary supports 21 are arranged outside the jacks 7. After the jacks 7 lift the original bridge T-beam web 14 to the designed height as a whole, the original bridge T-beam web 14 is temporarily supported by the stepped temporary supports 21, and the heightened T-beam bearing 5 is quickly replaced; a bearing pad stone 6 is arranged at the lower part of the T-beam bearing 5, and a leveling steel plate 20 is arranged at the upper part of the T-beam bearing 5.

[0093] As Figure 4 、 6 The overall drawing of the steel bar lapping at the wet joint of the original bridge T-beam and the widened bridge T-beam is shown, including the widened T-beam web 12, widened T-beam rib 13, original bridge T-beam web 14, original bridge T-beam rib 15, original bridge cast-in-place bridge deck 16, cut keyway of the original bridge cast-in-place bridge deck 17, keyway of the widened cast-in-place bridge deck 18, wet joint 19, steel bar mesh of the cast-in-place bridge deck 22, embedded rib bar 23, implanted rib bar 24, longitudinal bar of the wet joint 25, etc. A wet joint 19 is formed between the widened T-beam rib 13 and the original bridge T-beam rib 15. Embedded rib bars 23 are pre-embedded in the widened T-beam rib 13, and implanted rib bars 24 are implanted in the original bridge T-beam rib 15. The embedded rib bar 23 and the implanted rib bar 24 are lap-welded. Longitudinal bars 25 of the wet joint are welded along the longitudinal joint direction in the wet joint 19. A steel bar mesh of the cast-in-place bridge deck 22 is laid between the cut keyway 17 of the original bridge cast-in-place bridge deck and the keyway 18 of the widened cast-in-place bridge deck.

[0094] As Figure 4 、 8Structural diagram of the tension bracing system between the web of the original bridge T-beam and the widened T-beam web, including the widened T-beam web 12, the original bridge T-beam web 14, threaded holes 26, high-strength threaded steel bars 27, channel steel 28, load-bearing steel plates 29, anchor fittings 30, etc. Threaded holes 26 are drilled in the original bridge T-beam web 14, and threaded holes 26 are preset in the widened T-beam web 12. High-strength threaded steel bars 27 are passed through between the widened T-beam web 12 and the original bridge T-beam web 14 for tensioning. Both ends of the high-strength threaded steel bars 27 are anchored to the T-beam web through anchor fittings 30. When tensioning, channel steel 28 is arranged on both sides of the high-strength threaded steel bars 27 between the widened T-beam web 12 and the original bridge T-beam web 14, and load-bearing steel plates 29 are wedged tightly on both sides of the channel steel 28 to prevent the beam body from deforming; the high-strength threaded steel bars 27 exert a tensile force on the T-beam web, and the channel steel 28 exerts a bracing force on the T-beam web.

[0095] As Figure 5 Structural diagram of the integral steel cage of the diaphragm. The integral steel cage 36 of the diaphragm is composed of diaphragm horizontal bars 31, diaphragm vertical bars 32, L-shaped lifting bars 33, lifting bar connecting bars 34, etc. Diaphragms are evenly spaced between the original bridge T-beams and the widened T-beams. The diaphragms adopt the integral steel cage 36 of the diaphragm. L-shaped lifting bars 33 are arranged at the top of the integral steel cage 36 of the diaphragm. The L-shaped lifting bars 33 are thickened "L" steel bars, and lifting bar connecting bars 34 are arranged between adjacent L-shaped lifting bars 33 for strengthening connection.

[0096] As Figure 7 Detailed installation structure diagram of the integral steel cage of the diaphragm, including the widened T-beam web 12, the original bridge T-beam web 14, cast-in-place bridge deck steel mesh 22, rib plate embedded bars 23, rib plate implanted bars 24, diaphragm horizontal bars 31, L-shaped lifting bars 33, diaphragm horizontal bar reserved holes 35, integral steel cage 36 of the diaphragm, etc. Diaphragm horizontal bar reserved holes 35 are drilled on the original bridge T-beam web 14, and diaphragm horizontal bar reserved holes 35 are preset on the widened T-beam web 12. The lower diaphragm horizontal bars 31 of the integral steel cage 36 of the diaphragm are inserted into the diaphragm horizontal bar reserved holes 35 on both sides of the T-beam web. The L-shaped lifting bars 33 are hung on the edge of the T-beam rib plate and welded to the cast-in-place bridge deck steel mesh 22, rib plate embedded bars 23, and rib plate implanted bars 24.

[0097] As Figures 9 - 10 Detailed assembly structure diagram of the diaphragm formwork system. The diaphragm formwork system 37 is mainly composed of a standardized L-shaped formwork vertical plate 40, a standardized L-shaped formwork grooved bottom plate 41, a standardized insertable vertical plate 42, a card slot 43, etc. The standardized L-shaped formwork vertical plate 40 and the standardized L-shaped formwork grooved bottom plate 41 are an integral structure, and the standardized insertable vertical plate 42 can be freely inserted into the card slot 43.

[0098] As Figure 8 、 11Detailed drawings of the diaphragm formwork system and the integral steel cage installation structure as shown, including the widened T-beam web 12, the original bridge T-beam web 14, the integral steel cage of the diaphragm 36, the diaphragm formwork system 37, high-strength bolts 38, the supporting angle steel 39, the standardized L-shaped formwork vertical plate 40, the left side 40-1 of the vertical plate, the right side 40-2 of the vertical plate, the standardized L-shaped formwork grooved bottom plate 41, the standardized insertable vertical plate 42, etc. High-strength bolts 38 are driven on both the widened T-beam web 12 and the original bridge T-beam web 14 to fix the supporting angle steel 39. The diaphragm formwork system 37 is placed on the supporting angle steel 39. The integral steel cage of the diaphragm 36 is located on the standardized L-shaped formwork grooved bottom plate 41. The left side 40-1 and the right side 40-2 of the vertical plate of the standardized L-shaped formwork vertical plate 40 are respectively tightened against the original bridge T-beam web 14 and the widened T-beam web 12. The standardized L-shaped formwork grooved bottom plate 41 is placed on the supporting angle steel 39. The standardized L-shaped formwork vertical plate 40, the standardized L-shaped formwork grooved bottom plate 41, the standardized insertable vertical plate 42, the widened T-beam web 12, and the original bridge T-beam web 14 together form an uncovered "box". The top of this uncovered "box" is the cavity of the wet joint 19. Concrete is poured to integrally pour the diaphragm and the wet joint together.

[0099] The parts not detailed in this application are prior arts, so they are not elaborated in this application.

[0100] It can be understood that the term "one" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of an element can be one, while in other embodiments, the number of this element can be multiple. The term "one" cannot be understood as a limitation on the quantity.

[0101] Although many professional terms are used in this article, the possibility of using other terms is not excluded. These terms are only used to more conveniently describe and explain the essence of this application; interpreting them as any additional limitation is contrary to the spirit of this application.

[0102] This application is not limited to the above best implementation manner. Anyone can obtain other various forms of products under the inspiration of this application. However, no matter what changes are made in its shape or structure, as long as it has the same or similar technical solutions as this application, it falls within the protection scope of this application.

Claims

1. Construction method for splicing system of highway reconstruction and expansion bridge, characterized in that, it includes the following construction steps: S1. Construction preparation: Before the formal construction, prepare a special construction plan in accordance with the requirements for construction on the operating line. S2. Pier column and capping beam construction: Construct the widened pier columns (2) at the designed positions, and erect the widened bridge capping beams (4) on the upper parts of the widened pier columns (2). Detect whether the edges of the widened bridge capping beam (4) and the original bridge capping beam (3) are aligned. Install the lower steel section (8) and the upper steel section (9) between the widened bridge capping beam (4) and the original bridge capping beam (3) through chemical adhesive anchors (10), and weld angle steel (11) between the lower steel section (8) and the upper steel section (9) to connect the widened bridge capping beam (4) and the original bridge capping beam (3) into a whole. Install widened T-beams on the widened bridge capping beam (4). The dimensions of the widened T-beams are the same as those of the original bridge T-beams. The bottom bearings of the widened T-beams adopt new T-beam bearings (5) according to the designed elevation. S3. Jacking up and replacing the bearings of the original bridge T-beams: Symmetrically install jacks (7) under the lower parts of the webs (14) of all the original bridge T-beams and conduct a trial jacking. After the trial jacking is completed, install the stepped temporary supports (21). Lower the jacks (7) to place the webs (14) of the original bridge T-beams on the stepped temporary supports (21). Remove the original T-beam bearings (5), reinstall the bearing pads (6), install the heightened new T-beam bearings (5) on the bearing pads (6), raise the jacks (7), and remove the stepped temporary supports (21). Then slowly lower the jacks (7) to place the webs (14) of the original bridge T-beams on the new T-beam bearings (5), paste with epoxy resin, and detect whether the elevations of the tops of the ribs (15) of the original bridge T-beams and the tops of the ribs (13) of the widened T-beams are the same. S4. Drilling and implanting steel bars in the original bridge T-beams: Use a steel bar detector to detect the positions and embedment depths of the steel bars in the ribs (15) of the original bridge T-beams, drill holes with an impact drill, and avoid hitting the structural steel bars. After cleaning the residues in the holes, use a special injector or syringe to inject adhesive into the holes. Immediately after injecting the adhesive, insert the rib implant bars (24) into the ribs by rotating unidirectionally until reaching the designed depth. After the rib implant bars (24) are completely cured, weld them to the rib embedded bars (23) preset in the ribs (13) of the widened T-beams, and longitudinally weld the longitudinal wet joint bars (25) along the wet joint (19). At the same time, evenly spaced threaded holes (26) and transverse diaphragm transverse bar reserved holes (35) are drilled on the webs (14) of the original bridge T-beams. S5. Installation of T-beam web tension bracing system: Pass both ends of the high-strength threaded steel bars (27) through the threaded holes (26) on the webs (12) of the widened T-beams and the webs (14) of the original bridge T-beams respectively, and fix them through the anchor fittings (30). When applying tensile force to the high-strength threaded steel bars (27), set channel steels (28) on both sides between the webs (12) of the widened T-beams and the webs (14) of the original bridge T-beams and on both sides of the high-strength threaded steel bars (27), and wedge the bearing plates (29) on both sides of the channel steels (28) to prevent the T-beam webs from deforming under force. S6. Cutting and chiseling the original bridge deck paving concrete: According to the designed width, lay out the positioning line of the cutting keyway (17) of the original cast-in-place bridge deck, and use a cutting machine to cut to a depth of 10 mm. Use a pneumatic pick to chisel the concrete paving layer of the cutting keyway (17) of the original cast-in-place bridge deck. The exposed original cast-in-place bridge deck is fully roughened with a convexity and concavity of less than 6 mm. Insert shear key steel bars. After sufficient flushing, lay the steel mesh (22) of the cast-in-place bridge deck, and weld the steel mesh (22) of the cast-in-place bridge deck to the shear key steel bars. S7. Hoisting the integral steel cage (36) of the diaphragm wall: Hoist the pre-bundled integral steel cage (36) of the diaphragm wall to the designed position. Insert the lower cross diaphragm horizontal bars (31) of the integral steel cage (36) of the diaphragm wall into the reserved holes (35) of the cross diaphragm horizontal bars on the webs of the T-beams on both sides. The upper part is suspended by L-shaped lifting bars (33) at the edge of the T-beam rib plate and welded to the steel mesh (22) of the cast-in-place bridge deck, the embedded bars (23) of the rib plate, and the implanted bars (24) of the rib plate. S8. Installing the formwork system (37) of the diaphragm wall: Drive high-strength bolts (38) at the designed positions on the widened T-beam web (12) and the original bridge T-beam web (14) to fix the supporting angle steel (39), and place the standardized L-shaped formwork with a grooved bottom plate (41) on the supporting angle steel (39). The left side (40-1) and the right side (40-2) of the vertical plate of the standardized L-shaped formwork vertical plate (40) are tightly abutted against the original bridge T-beam web (14) and the widened T-beam web (12) respectively. The integral steel cage (36) of the diaphragm wall is located 20 mm above the standardized L-shaped formwork with a grooved bottom plate (41). Insert the standardized insertable vertical plate (42) into the card slot (43) of the standardized L-shaped formwork with a grooved bottom plate (41) to form an uncovered "box", and place the integral steel cage (36) of the diaphragm wall in the box. S9. Integral pouring of the diaphragm wall and the wet joint: Pour concrete into the wet joint (19), and integrally pour the concrete of the diaphragm wall and the wet joint to form a whole. S10. Pouring compensated shrinkage concrete: After the concrete strength of the diaphragm wall and the wet joint (19) reaches the designed requirements, pour compensated shrinkage concrete between the cutting keyway (17) of the original cast-in-place bridge deck and the keyway (18) of the widened cast-in-place bridge deck. Finally, construct the bridge deck paving layer and resume bridge traffic.

2. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 1, characterized in that, In step S4, a wet joint (19) is formed between the widened T-beam rib plate (13) and the original bridge T-beam rib plate (15).

3. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 1, characterized in that, In step S5, threaded holes (26) are drilled in the original bridge T-beam web (14), and threaded holes (26) are also preset in the widened T-beam web (12). The widened T-beam web (12) and the original bridge T-beam web (14) are tensioned by passing through high-strength threaded steel bars (27).

4. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 1, characterized in that, In step S7, diaphragms are evenly spaced between the original bridge T-beams and the widened T-beams. The diaphragms adopt an integral steel reinforcement cage for diaphragms (36). Transverse reinforcement reserved holes (35) are drilled in the webs (14) of the original bridge T-beams, and transverse reinforcement reserved holes (35) are also preset in the webs (12) of the widened T-beams.

5. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 1, characterized in that, In step S8, the diaphragm formwork system (37) includes a standardized L-shaped formwork vertical plate (40), a standardized L-shaped formwork grooved bottom plate (41) and a standardized insertable vertical plate (42). The standardized L-shaped formwork vertical plate (40) and the standardized L-shaped formwork grooved bottom plate (41) are of an integral structure.

6. The construction method of the highway reconstruction and expansion bridge splicing system according to any one of claims 1-5, characterized in that, In step S3, the jacks (7) are symmetrically arranged on both sides of the bottom of the web (14) of the original bridge T-beam. A stepped temporary support (21) is arranged outside the jacks (7). A bearing pad stone (6) is arranged below the T-beam bearing (5), and a leveling steel plate (20) is arranged above the T-beam bearing (5).

7. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 6, characterized in that, In step S3, check whether there is a phenomenon of bearing void. If there is a bearing void phenomenon, it is necessary to re-lift. Fill the gap between the web (14) of the original bridge T-beam and the new T-beam bearing (5) with a thin leveling steel plate (20) to ensure that the web (14) of the original bridge T-beam is completely in close contact with the new T-beam bearing (5) and the top elevation of the rib plate (15) of the original bridge T-beam is flush with the top elevation of the rib plate (13) of the widened T-beam.

8. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 7, characterized in that, In step S7, the integral steel reinforcement cage for diaphragms (36) includes transverse diaphragm reinforcement (31), vertical diaphragm reinforcement (32), L-shaped lifting bars (33) and lifting bar connecting bars (34). The L-shaped lifting bars (33) are thickened "L" steel bars, and lifting bar connecting bars (34) are arranged between adjacent L-shaped lifting bars (33) for strengthening connection.

9. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 7, characterized in that, In step S8, the top of the "box" without a cover is a wet joint (19) cavity.

10. The construction method of the highway reconstruction and expansion bridge splicing system according to claim 7, characterized in that, In step S3, after the trial lift is completed, the beam body is officially lifted synchronously according to the designed lifting height. After lifting to the designed elevation, it is over-lifted by about 10 cm, and the stepped temporary support (21) is installed.

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