Precast lattice girder secondary cable-tensioned steel reinforced concrete joint structure and construction method

Abstract

The invention discloses a prefabricated lattice girder secondary cable-stayed steel reinforced concrete joint structure and a construction method thereof, which include construction steps such as prefabricated lattice girder production, beam groove excavation, prefabricated lattice girder installation, installation of the lower steel skeleton of the cross-laminated joint, installation of the upper steel skeleton of the cross-laminated joint, steel bar binding at the cross-laminated joint part, cable construction and primary tensioning, laminated concrete pouring, secondary cable-stayed tensioning, backfilling and greening, etc.; the reserved bars of the prefabricated lattice girder are processed by penetration or bending with the steel skeleton, and stud bolts are welded on the inner and outer sides of the steel skeleton, effectively improving the integrity of the prefabricated lattice girder and the cross-laminated joint part; the secondary cable-stayed cable is initially tensioned after the installation of the prefabricated lattice girder and the steel skeleton. The initial tensioning can form a certain protection for the slope, greatly reduce the time of the slope in the unprotected exposed state, effectively ensure the safety during the slope construction process, and reduce the risks existing during the construction process.

Description

Technical Field

[0001] The present invention relates to the construction of precast lattice beam slope protection, and particularly to a secondary cable tensioning steel reinforced concrete joint structure and construction method for precast lattice beams. Background Art

[0002] When traditional lattice beams are used for supporting building slopes, highway slopes and railway slopes, cast-in-place reinforced concrete is generally adopted. However, there are many problems with cast-in-place construction: 1. It is difficult to set up formwork on the slope surface. A large number of workers are required for steel bar binding and formwork erection, resulting in low construction efficiency; 2. During the pouring and vibration of concrete, quality problems such as incomplete vibration and formwork displacement of the beam body are likely to occur, leading to the collapse of the lattice beam and affecting the supporting effect; 3. The cast-in-place construction period is long, resulting in the slope being in an exposed state, increasing the probability of being washed by rainwater, which is extremely unfavorable for the stability of the slope.

[0003] Under this background, the precast lattice beam technology has developed rapidly due to its advantages such as high construction efficiency and short construction period. However, during the construction process of precast lattice beams, there are still the following problems in joint treatment: 1. The joints between the cross beams and vertical beams are designed with cast-in-place construction. Only after reaching the strength can they effectively protect the slope surface. The slope is in an unprotected and exposed state for a long time, with a certain risk of collapse; 2. The joints are tied with steel bars, and the tying difficulty is relatively large; 3. The cast-in-place joint part is a weak link, which also has a certain impact on the construction of anchor cables (rods), affecting the construction progress. Summary of the Invention

[0004] The purpose of the present invention is to propose a secondary cable tensioning steel reinforced concrete joint structure and construction method for precast lattice beams in view of the problems existing in the construction of existing precast lattice beams for slope protection.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions.

[0006] The secondary cable tensioning steel reinforced concrete joint structure for precast lattice beams is composed of precast lattice beams and reserved steel bars, steel skeletons, secondary tensioning anchor cables and composite concrete.

[0007] Step joints are provided on both sides of the precast lattice beams. Horizontal reserved steel bars are provided on the upper layer of the step joints, and bent reserved steel bars and horizontal reserved steel bars are provided on the lower layer of the step joints.

[0008] The steel skeleton includes the lower steel skeleton of the stepped joint lower layer and the upper steel skeleton of the stepped joint upper layer. The lower steel skeleton consists of a square bottom plate, a cross-connected top plate, a connecting cylinder body, and lower stiffening rib plates. The upper steel skeleton consists of a cross-connected bottom plate, a stress-bearing top plate, a connecting cylinder body, and upper stiffening rib plates. The center of the square bottom plate and the cross-connected top plate are provided with cable anchor holes. The four corners of the square bottom plate are provided with reserved rib notches that match the lengths of the bent reserved ribs and the horizontal reserved ribs. Moreover, the cross-connected top plate is also provided with bolt holes, grouting holes, and bent reinforcement reserved holes. The four side plates of the cross-connected top plate are fixed to the stepped joint layer of the precast lattice beam through connecting bolts and corresponding bolt holes. The cross-connected bottom plate is provided with cable anchor holes, bolt holes, grouting holes, and bent reinforcement reserved holes that correspond one by one to those of the cross-connected top plate. The stress-bearing top plate is provided with cable anchor holes and grouting holes. The lower stiffening rib plates and the upper stiffening rib plates are evenly arranged around the connecting cylinder body and are fixedly connected to the upper and lower ends.

[0009] The secondary tension cable anchor is arranged above the upper steel skeleton, and an anchor backing plate is provided above the stress-bearing top plate. The secondary tension cable anchor is initially tensioned after the installation of the precast lattice beam and the steel skeleton, and is tensioned a second time after the casting of the composite concrete.

[0010] The composite concrete fills the gap between the superimposed cavity of the precast lattice beam and the steel skeleton.

[0011] Preferably, the height of the upper layer of the stepped joint is 1 / 3 of the cross-section height of the precast lattice beam, and the height of the lower layer of the stepped joint is 2 / 3 of the cross-section height of the precast lattice beam. The bent reserved ribs are located at the center line position of the cross-section of the precast lattice beam.

[0012] Preferably, the adjacent stepped joint horizontal reserved ribs of the precast lattice beam are tied and lengthened with extended ribs to form a whole.

[0013] Preferably, the central square of the cross-connected top plate has the same size as the square bottom plate.

[0014] Preferably, the grouting hole consists of two holes that communicate the inside and outside of the connecting cylinder body.

[0015] Preferably, the cross-section of the lower stiffening rib plate is an inverted trapezoid, with the short side fixedly connected to the square bottom plate and the long side fixedly connected to the cross-connected top plate. The cross-section of the upper stiffening rib plate is a regular trapezoid, with the short side fixedly connected to the stress-bearing top plate and the long side fixedly connected to the cross-connected bottom plate.

[0016] Preferably, the connecting cylinder body is a cylindrical barrel arranged between the square bottom plate and the cross-connected top plate, and between the cross-connected bottom plate and the stress-bearing top plate. Studs are evenly arranged on the inner and outer sides of the connecting cylinder body inside the upper and lower steel skeletons.

[0017] Preferably, the precast lattice beam comprises a cross beam and a vertical beam. The top of the vertical beam is connected to the slope top beam, and the bottom of the vertical beam is connected to the slope bottom beam. A slope top catch water channel and a slope bottom catch water channel are respectively arranged outside the slope top beam and the slope bottom beam. The area enclosed by the precast lattice beams is a planting area, and a mortar cushion layer, a planting soil layer and greening plants are successively arranged in the planting area from bottom to top.

[0018] Preferably, the slope protection construction method for the cast-in-place profiled steel concrete joint structure with secondary anchor cable tensioning of the precast lattice beam comprises the following steps:

[0019] S1. Production of precast lattice beams: Precast lattice beams with stepped joints on both sides are precast in a factory.

[0020] S2. Excavation of beam grooves: The slope is trimmed, and beam grooves are excavated according to the position and size of the precast lattice beams.

[0021] S3. Installation of precast lattice beams:

[0022] S3.1. Construction of mortar cushion layer in the excavated beam grooves;

[0023] S3.2. Install the precast lattice beams above the mortar cushion layer. A square overlapping area is reserved between the left and right cross beams and the upper and lower vertical beams, and a cross overlapping joint is formed with the stepped joints of the precast lattice beams.

[0024] S3.3. The top of the vertical beam extends into the slope top beam, and the bottom of the vertical beam extends into the slope bottom beam.

[0025] S4. Installation of the lower profiled steel skeleton of the cross overlapping joint:

[0026] S4.1. Drill anchor cable holes at the center positions of the square bottom plate and the cross connecting top plate, and drill bolt holes, grouting holes and reserved holes for bent reinforcement on the cross connecting top plate.

[0027] S4.2. Weld the square bottom plate and the cross connecting top plate to the upper and lower ends of the connecting cylinder body respectively, and evenly weld lower stiffening rib plates around the connecting cylinder body to form the lower profiled steel skeleton.

[0028] S4.3. Fix the square bottom plate of the lower profiled steel skeleton in the square overlapping area between the precast lattice beams. The bent reserved reinforcement of the precast lattice beam passes through the reserved holes for bent reinforcement of the corresponding cross connecting top plate, and the four side plates of the cross connecting top plate overlap on the stepped joint layer of the precast lattice beam.

[0029] S5. Installation of the upper profiled steel skeleton of the cross overlapping joint:

[0030] S5.1. Drill anchor cable holes, bolt holes, grouting holes and reserved holes for bent reinforcement at the center position of the cross connecting bottom plate; Drill matching anchor cable holes and grouting holes on the stressed top plate.

[0031] S5.2. Weld the stressed roof slab and the cross - connecting bottom slab to the upper and lower ends of the connecting cylinder body respectively, and evenly weld the upper stiffening rib plates around the connecting cylinder body to form the upper steel skeleton;

[0032] S5.3. Overlap and lap the cross - connecting bottom slab of the upper steel skeleton and the cross - connecting top slab of the lower steel skeleton section by section, and fix the four side plates of the cross - connecting bottom slab and the cross - connecting top slab to the stepped joint layer of the precast lattice beam through connecting bolts;

[0033] S6. Steel bar binding at the cross - laminated joint part: Bind and splice the horizontally reserved steel bars of adjacent precast lattice beam stepped joints at the cross - laminated joint part with extended steel bars to form an integral body;

[0034] S7. Anchor cable construction and primary tensioning: Drill anchor cable installation holes at the positions of the anchor cable holes of the cross - laminated joint, install the anchor cables into the anchor cable installation holes and grout, fix the anchor cables to the stressed roof slab at the top of the upper steel skeleton through the anchor backing plate, and conduct primary tensioning. The tensioning force is 30% of the design tensioning value, so that the precast lattice beam and the anchor cable form a support system and generate an initial anchoring force;

[0035] S8. Casting of the laminated concrete: Pour the laminated concrete into the gap between the precast lattice beam and the steel skeleton through the grouting hole to make the left and right lattice cross - beams and the upper and lower lattice vertical beams form an integral body;

[0036] S9. Secondary tensioning of the anchor cable: Conduct secondary tensioning on the secondary tensioning anchor cable to reach 100% of the design tensioning value;

[0037] S10. Backfilling and greening: The planting areas enclosed by the precast lattice beams are backfilled with a gravel layer and a planting soil layer in sequence from bottom to top, and greening plants are planted in the planting soil layer.

[0038] The beneficial effects of the technical solution involved in the present invention compared with the traditional technology are as follows:

[0039] 1. The reserved steel bars of the precast lattice beam are penetrated or bent and welded with stud bolts on the inner and outer sides of the steel skeleton, effectively improving the integrity of the precast lattice beam and the cross - laminated joint part; The secondary tensioning anchor cable supports the steel members, thus forming an integral slope protection system of the precast lattice beam, laminated joint and anchor cable. The slope protection has strong integrity and good stability, and the lattice beam is not easy to collapse.

[0040] 2. The anchor cable is initially tensioned after the installation of the precast lattice beam and the steel skeleton. After the initial tensioning, certain protection can be provided for the slope, greatly reducing the time of the slope in the un - supported exposed state, effectively ensuring the safety during the slope construction process and reducing the risks existing during the construction process.

[0041] 3. After the laminated concrete is poured, the anchor cable is tensioned for the second time. The anchor cable can be effectively combined with the laminated concrete and provide complete protection for the slope protection.

[0042] 4. The construction of the lattice beam and the cross laminated joint does not require formwork support. The steel skeleton is installed into the laminated cavity between the ends of the precast lattice beam. The installation speed is fast, and the square bottom plate at the bottom of the steel skeleton can ensure the installation accuracy of the skeleton, effectively improving the construction efficiency and quality and reducing the construction period.

[0043] 5. During the construction of the lattice beam, only the joint part needs to be tied with steel bars. The construction steps are greatly reduced, and the appearance quality of the precast components is good, and the final forming quality of the lattice beam is good.

[0044] 6. The precast lattice beam and the steel skeleton can be produced in a factory, standardized and specialized manner. Precast components with different cross-sections and sizes can be produced according to the slope protection conditions, and the scope of application is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is the side view of the slope protection of the precast lattice beam secondary anchor cable tensioning cast-in-place steel-concrete joint structure;

[0046] Figure 2 is the sectional view of the planting area of the slope protection of the precast lattice beam secondary anchor cable tensioning cast-in-place steel-concrete joint structure ( Figure 1 section A-A in);

[0047] Figure 3 is the sectional view of the precast lattice beam of the slope protection of the precast lattice beam secondary anchor cable tensioning cast-in-place steel-concrete joint structure ( Figure 1 section B-B in);

[0048] Figure 4 is the schematic diagram of the precast lattice beam secondary anchor cable tensioning cast-in-place steel-concrete joint structure;

[0049] Figure 5 is the schematic diagram of the precast lattice beam structure;

[0050] Figure 6 is the three-dimensional schematic diagram of the precast lattice beam structure;

[0051] Figure 7 is the connection schematic diagram of the upper steel skeleton and the lower steel skeleton;

[0052] Figure 8 is the cross-sectional view of the cruciform connecting plate of the upper steel skeleton and the lower steel skeleton ( Figure 7 section C-C in);

[0053] Figure 9 is the cross-sectional view of the square bottom plate of the upper steel skeleton and the lower steel skeleton ( Figure 7 section D-D in);

[0054] Figure 10 is a three-dimensional schematic diagram of the upper steel skeleton and the lower steel skeleton;

[0055] Figure 11 is a structural schematic diagram of the lower steel skeleton;

[0056] Figure 12 is a three-dimensional schematic diagram of the lower steel skeleton;

[0057] Figure 13 is a structural schematic diagram of the upper steel skeleton;

[0058] Figure 14 is a three-dimensional schematic diagram of the upper steel skeleton;

[0059] Figure 15 is a schematic diagram of the connection of precast lattice beams and superimposed cavities;

[0060] Figure 16 is a schematic diagram of the installation of the connection between precast lattice beams and steel skeletons;

[0061] Figure 17 is a schematic diagram of the excavation of the secondary anchor cable tensioning slope protection beam groove of the precast lattice beam steel-concrete joint (step S2);

[0062] Figure 18 is a schematic diagram of the installation of the precast lattice beam of the secondary anchor cable tensioning slope protection of the precast lattice beam steel-concrete joint (step S3);

[0063] Figure 19 is a schematic diagram of the installation of the lower steel skeleton of the cross-superimposed joint of the precast lattice beam steel-concrete joint for secondary anchor cable tensioning slope protection (step S4);

[0064] Figure 20 is a schematic diagram of the installation of the upper steel skeleton of the cross-superimposed joint of the precast lattice beam steel-concrete joint for secondary anchor cable tensioning slope protection (step S5);

[0065] Figure 21 is a schematic diagram of the pouring of the superimposed concrete of the precast lattice beam steel-concrete joint for secondary anchor cable tensioning slope protection (step S8);

[0066] Figure 22 is a construction flow chart of the construction method for the structure of the precast lattice beam secondary anchor cable tensioning cast-in-place steel-concrete joint and slope protection.

[0067] Labels in the figure: 1 - precast lattice beam, 101 - horizontal reserved reinforcement, 102 - bent reserved reinforcement, 103 - stepped joint, 2 - cross-laminated joint, 201 - upper steel skeleton, 202 - lower steel skeleton, 203 - laminated concrete, 204 - laminated cavity, 3 - square bottom plate, 301 - reserved reinforcement notch, 401 - bolt hole, 402 - anchor cable hole, 403 - grouting hole, 404 - cross-connected top plate, 405 - cross-connected bottom plate, 406 - bent reinforcement reserved hole, 5 - connecting cylinder body, 601 - lower stiffening rib plate, 602 - upper stiffening rib plate, 7 - stress-bearing top plate, 8 - secondary tensioned anchor cable, 9 - anchor backing plate, 1001 - slope top beam, 1002 - slope bottom beam, 1101 - slope top catch water channel, 1102 - slope bottom catch water channel, 12 - gravel layer, 13 - planting soil layer, 14 - greening plants, 15 - planting area, 16 - beam groove, 17 - extended reinforcement, 18 - mortar cushion layer, 19 - stud, 20 - connecting bolt. Specific implementation mode

[0068] To deepen the understanding of the present invention, the following will refer to Figures 1 to 22 , and make a detailed description of the embodiments of the present invention. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation modes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0069] In this embodiment, the size of the precast lattice beam 1 is 3m × 3m, the cross-sectional size is 250mm × 300mm, the horizontal reserved reinforcement 101 is the main reinforcement of the precast lattice beam 1, the bent reserved reinforcement 102 is the embedded reinforcement in the middle of the cross-section of the precast lattice beam 1, the position of the secondary tensioned anchor cable 8 is arranged at the center of the cross intersection of the lattice beam, the anchor cable spacing is 3m horizontally and 3m vertically; the cross-sectional size of the square bottom plate 3 of the cross-laminated joint 2 is 300mm × 300mm, the cross-sectional shape of the cross-shaped connecting plate is a 300mm × 300mm square in the center, and it is combined with the side plates of 300mm × 150mm on the four sides; the cross-sectional size of the stepped joint 103 of the precast lattice beam 1 is 300mm × 300mm.

[0070] Combined with attached Figure 1 、attached Figure 3 As shown, the precast lattice beam 1 includes a cross beam and a vertical beam. The top of the vertical beam is connected to the slope top beam 1001, the bottom of the vertical beam is connected to the slope bottom beam 1002, and a slope top catch water channel 1101 and a slope bottom catch water channel 1102 are respectively arranged on the outer sides of the slope top beam 1001 and the slope bottom beam 1002; the area enclosed by the precast lattice beams is the planting area 15, and the planting area 15 is successively provided with a mortar cushion layer 18, a planting soil layer 13 and greening plants 14 from bottom to top.

[0071] Combined with attached Figure 2 、attached Figure 5 、attached Figure 6As shown, stepped joints 103 are provided on both sides of the precast lattice beam 1. Horizontal reserved bars 101 are provided on the upper layer of the stepped joint 103, and bent reserved bars 102 and horizontal reserved bars 101 are provided on the lower layer of the stepped joint 103. The height of the upper layer of the stepped joint 103 is 1 / 3 of the cross-sectional height of the precast lattice beam 1, and the height of the lower layer of the stepped joint 103 is 2 / 3 of the cross-sectional height of the precast lattice beam 1. The bent reserved bar 102 is located at the center line position of the cross-section of the precast lattice beam 1.

[0072] Combined with the attached Figure 4 、attached Figure 7 、attached Figure 10 As shown, the steel skeleton includes a lower steel skeleton 202 in the lower layer of the stepped joint 103 and an upper steel skeleton 201 in the upper layer of the stepped joint 103. The lower steel skeleton 202 is composed of a square bottom plate 3, a cross-connected top plate 404, a connecting cylinder body 5, and a lower stiffening rib plate 601. The upper steel skeleton 201 is composed of a cross-connected bottom plate 405, a stress-bearing top plate 7, a connecting cylinder body 5, and an upper stiffening rib plate 602. Then combined with the attached Figure 8 、attached Figure 9 As shown, cable anchor holes 402 are provided at the central parts of the square bottom plate 3 and the cross-connected top plate 404. Reserved bar cutouts 301 matching the lengths of the bent reserved bars 102 and the horizontal reserved bars 101 are provided at the four corners of the square bottom plate 3. Moreover, bolt holes 401, grouting holes 403, and bent bar reserved holes 406 are also provided on the cross-connected top plate 404. The central square of the cross-connected top plate 404 has the same size as the square bottom plate 3.

[0073] Combined with the attached Figure 2 、attached Figure 4 、attached Figure 8 As shown, the four side plates of the cross-connected top plate 404 are fixed to the stepped joint 103 layer of the precast lattice beam 1 through connecting bolts 20 and the corresponding bolt holes 401. Then combined with the attached Figure 13 、attached Figure 14 As shown, the cross-connected bottom plate 405 is provided with cable anchor holes 402, bolt holes 401, grouting holes 403, and bent bar reserved holes 406 corresponding to the cross-connected top plate 404 one by one. Cable anchor holes 402 and grouting holes 403 are provided on the stress-bearing top plate 7.

[0074] Combined with the attached Figure 11 ~attached Figure 14 As shown, the cross-section of the lower stiffening rib plate 601 is an inverted trapezoid, with the short side fixedly connected to the square bottom plate 3 and the long side fixedly connected to the cross-connected top plate 404. The cross-section of the upper stiffening rib plate 602 is a regular trapezoid, with the short side fixedly connected to the stress-bearing top plate 7 and the long side fixedly connected to the cross-connected bottom plate 405. Then combined with the attached Figure 7As shown, the connecting cylinder body 5 is a cylindrical barrel provided between the square bottom plate 3 and the cross-shaped connecting top plate 404, and between the cross-shaped connecting bottom plate 405 and the stress-bearing top plate 7. Studs 19 are evenly arranged on the inner and outer sides of the connecting cylinder body 5 inside the upper steel skeleton 201 and the lower steel skeleton 202; the grouting hole 403 is composed of two holes communicating the inside and outside of the connecting cylinder body 5.

[0075] Combined with the attached Figure 2 , attached Figure 4 , attached Figure 16 As shown, the secondary tension anchor cable 8 is arranged above the upper steel skeleton 201, and an anchor backing plate 9 is provided above the stress-bearing top plate 7; combined with the attached Figure 20 , attached Figure 21 As shown, the secondary tension anchor cable 8 is initially tensioned after the precast lattice beam 1 and the steel skeleton are installed, and is secondarily tensioned after the composite concrete 203 is poured.

[0076] Combined with the attached Figure 1 , attached Figure 2 , attached Figure 4 As shown, the composite concrete 203 fills the gap between the composite cavity 204 of the precast lattice beam 1 and the steel skeleton; the horizontal reserved bars 101 of the adjacent stepped joints 103 of the precast lattice beam 1 are tied and lengthened with the lengthened bars 17 to form an integral body.

[0077] For the above, combined with the attached Figure 22 , the following construction steps are adopted:

[0078] S1. Production of the precast lattice beam 1: Combined with the attached Figure 5 , attached Figure 6 As shown, the precast lattice beam 1 with stepped joints 103 on both sides is precast in the factory.

[0079] S2. Excavation of the beam groove 16: Combined with the attached Figure 17 As shown, the slope is trimmed, and the beam groove 16 is excavated according to the position and size of the precast lattice beam 1.

[0080] S3. Installation of the precast lattice beam 1: Combined with the attached Figure 2 , attached Figure 15 , attached Figure 18 As shown.

[0081] S3.1. Construction of the mortar cushion layer 18 in the excavated beam groove 16.

[0082] S3.2. Install the precast precast lattice beam 1 above the mortar cushion layer 18, leaving a square composite area between the left and right cross beams and the upper and lower vertical beams, and forming a cross-shaped composite joint 2 with the stepped joint 103 of the precast lattice beam 1.

[0083] S3.3. The top of the vertical beam extends into the inside of the slope top beam 1001, and the bottom of the vertical beam extends into the inside of the slope bottom beam 1002.

[0084] S4. Installation of the lower steel skeleton 202 of the cross-laminated joint 2: Refer to Attachment Figure 11 Attachment Figure 12 Attachment Figure 19 as shown.

[0085] S4.1. Drill cable anchor holes 402 at the central parts of the square bottom plate 3 and the cross-connected top plate 404, and drill bolt holes 401, grouting holes 403, and bent reinforcement reserved holes 406 on the cross-connected top plate 404.

[0086] S4.2. Weld the square bottom plate 3 and the cross-connected top plate 404 to the upper and lower ends of the connecting cylinder body 5 respectively, and evenly weld lower stiffening rib plates 601 around the connecting cylinder body 5 to form the lower steel skeleton 202.

[0087] S4.3. Fix the square bottom plate 3 of the lower steel skeleton 202 in the square laminated area between the precast lattice girders 1. The bent reserved reinforcement 102 of the precast lattice girder 1 passes through the corresponding bent reinforcement reserved holes 406 of the cross-connected top plate 404, and the four side plates of the cross-connected top plate 404 overlap on the stepped joint 103 layer of the precast lattice girder 1.

[0088] S5. Installation of the upper steel skeleton 201 of the cross-laminated joint 2: Refer to Attachment Figure 7 to Attachment Figure 10 Attachment Figure 13 Attachment Figure 14 Attachment Figure 16 Attachment Figure 20 as shown.

[0089] S5.1. Drill cable anchor holes 402, bolt holes 401, grouting holes 403, and bent reinforcement reserved holes 406 at the central part of the cross-connected bottom plate 405; drill matching cable anchor holes 402 and grouting holes 403 on the load-bearing top plate 7.

[0090] S5.2. Weld the load-bearing top plate 7 and the cross-connected bottom plate 405 to the upper and lower ends of the connecting cylinder body 5 respectively, and evenly weld upper stiffening rib plates 602 around the connecting cylinder body 5 to form the upper steel skeleton 201.

[0091] S5.3. Overlap the cross section of the cross-connected bottom plate 405 of the upper steel skeleton 201 and the cross-connected top plate 404 of the lower steel skeleton 202, and fix the four side plates of the cross-connected bottom plate 405 and the cross-connected top plate 404 to the stepped joint 103 layer of the precast lattice girder 1 through connecting bolts 20.

[0092] S6. Steel bar binding at the cross-laminated joint 2 part: Refer to Attachment Figure 2As shown in the figure, the extended bars 17 are used to bind and extend the horizontally reserved bars 101 of the stepped joint 103 of the adjacent precast lattice girders 1 at the cross-laminated joint 2 part to form a whole.

[0093] S7. Anchor cable construction and primary tensioning: Combine with Appendix Figure 2 , Appendix Figure 3 As shown in the figure, at the position of the anchor cable hole 402 of the cross-laminated joint 2, drill an anchor cable installation hole, install the anchor cable into the anchor cable installation hole and grout, fix the anchor cable to the top stressed roof 7 of the upper steel skeleton 201 through the anchor plate 9, and perform primary tensioning. The tensioning force is 30% of the designed tensioning value, so that the precast lattice girder 1 and the anchor cable form a support system and generate an initial anchoring force.

[0094] S8. Casting of the laminated concrete 203: Combine with Appendix Figure 4 , Appendix Figure 21 As shown in the figure, through the grouting hole 403, cast the laminated concrete 203 into the gap between the precast lattice girder 1 and the steel skeleton, so that the left and right lattice cross beams and the upper and lower lattice vertical beams form a whole.

[0095] S9. Secondary tensioning of the anchor cable: Combine with Appendix Figure 2 , Appendix Figure 3 As shown in the figure, perform secondary tensioning on the secondary tensioning anchor cable 8 to reach 100% of the designed tensioning value.

[0096] S10. Backfilling and greening: Combine with Appendix Figure 1 , Appendix Figure 2 , Appendix Figure 3 As shown in the figure, the planting areas 15 enclosed by the precast lattice girders 1 are backfilled with a gravel layer 12 and a planting soil layer 13 in sequence from bottom to top, and greening plants 14 are planted in the planting soil layer 13.

[0097] The above embodiments are only used to explain the technical concept of the present invention, rather than limiting the protection scope of the rights of the present invention. Any non-substantive modification made to the present invention using this concept shall fall within the protection scope of the present invention.

Claims

1. The precast lattice girder secondary cable-tensioned steel reinforced concrete joint structure is characterized in that It is composed of a precast lattice beam (1), reserved reinforcement bars, a steel skeleton, a secondary tension anchor cable (8), and a composite concrete (203); on both sides of the precast lattice beam (1), there are stepped joints (103), on the upper layer of the stepped joint (103), there are horizontal reserved reinforcement bars (101), and on the lower layer of the stepped joint (103), there are bent reserved reinforcement bars (102) and horizontal reserved reinforcement bars (101). The steel skeleton includes a lower steel skeleton (202) at the lower layer of the stepped joint (103) and an upper steel skeleton (201) at the upper layer of the stepped joint (103). The lower steel skeleton (202) is composed of a square bottom plate (3), a cross-connected top plate (404), a connecting cylinder body (5), and lower stiffening rib plates (601). The upper steel skeleton (201) is composed of a cross-connected bottom plate (405), a stress-bearing top plate (7), a connecting cylinder body (5), and upper stiffening rib plates (602); in the central parts of the square bottom plate (3) and the cross-connected top plate (404), there are anchor cable holes (402). At the four corners of the square bottom plate (3), there are reserved reinforcement bar cutouts (301) matching the lengths of the bent reserved reinforcement bars (102) and the horizontal reserved reinforcement bars (101). And on the cross-connected top plate (404), there are also bolt holes (401), grouting holes (403), and bent reinforcement bar reserved holes (406); the four side plates of the cross-connected top plate (404) are fixed to the stepped joint (103) layer of the precast lattice beam (1) through connecting bolts (20) and corresponding bolt holes (401); the cross-connected bottom plate (405) is provided with anchor cable holes (402), bolt holes (401), grouting holes (403), and bent reinforcement bar reserved holes (406) corresponding to the cross-connected top plate (404) one by one. On the stress-bearing top plate (7), there are anchor cable holes (402) and grouting holes (403); the lower stiffening rib plates (601) and the upper stiffening rib plates (602) are evenly arranged around the connecting cylinder body (5) and are fixedly connected to the upper and lower ends. The secondary tension anchor cable (8) is arranged above the upper steel skeleton (201), and an anchor backing plate (9) is arranged above the stress-bearing top plate (7); the secondary tension anchor cable (8) is initially tensioned after the installation of the precast lattice beam (1) and the steel skeleton, and is secondarily tensioned after the pouring of the composite concrete (203). The composite concrete (203) fills the gap between the composite cavity (204) of the precast lattice beam (1) and the steel skeleton.

2. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, characterized in that The height of the upper layer of the stepped joint (103) is 1 / 3 of the cross-sectional height of the precast lattice beam (1), and the height of the lower layer of the stepped joint (103) is 2 / 3 of the cross-sectional height of the precast lattice beam (1). The bent reserved reinforcement bar (102) is located at the center line position of the cross-section of the precast lattice beam (1).

3. The precast lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, wherein The horizontal reserved reinforcement bars (101) of adjacent stepped joints (103) of the precast lattice beam (1) are tied and extended with extended reinforcement bars (17) to form a whole.

4. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, characterized in that, The central square of the cross-connected top plate (404) has the same size as the square bottom plate (3).

5. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, wherein The grouting hole (403) is composed of two holes communicating the inside and outside of the connecting cylinder body (5).

6. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, characterized in that, The cross-section of the lower stiffening rib plate (601) is an inverted trapezoid, with the short side fixedly connected to the square bottom plate (3) and the long side fixedly connected to the cross-connected top plate (404); the cross-section of the upper stiffening rib plate (602) is a regular trapezoid, with the short side fixedly connected to the stress-bearing top plate (7) and the long side fixedly connected to the cross-connected bottom plate (405).

7. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, characterized in that, The connecting cylinder body (5) is a cylindrical barrel body provided between the square bottom plate (3) and the cross-connected top plate (404), and between the cross-connected bottom plate (405) and the stress-bearing top plate (7). Studs (19) are evenly arranged on the inner and outer sides of the connecting cylinder body (5) inside the upper steel skeleton (201) and the lower steel skeleton (202).

8. The prefabricated lattice girder secondary cable-tensioned steel reinforced concrete joint structure according to claim 1, characterized in that, The precast lattice beam (1) includes a cross beam and a vertical beam. The top of the vertical beam is connected to the slope top beam (1001), and the bottom of the vertical beam is connected to the slope bottom beam (1002). A slope top catchment ditch (1101) and a slope bottom catchment ditch (1102) are respectively arranged on the outer sides of the slope top beam (1001) and the slope bottom beam (1002); the area enclosed by the precast lattice beams is a planting area (15), and a mortar cushion layer (18), a planting soil layer (13) and greening plants (14) are successively arranged in the planting area (15) from bottom to top.

9. A construction method for a secondary cable tensioned profiled steel concrete joint structure of a precast lattice girder according to any one of claims 1 to 8, characterized in that, It includes the following steps: S1. Production of the precast lattice beam (1): Precast the precast lattice beam (1) with stepped joints (103) on both sides in the factory; S2. Excavation of the beam groove (16): Trim the slope and excavate the beam groove (16) according to the position and size of the precast lattice beam (1); S3. Installation of the precast lattice beam (1): S3.

1. Construct the mortar cushion layer (18) in the excavated beam groove (16); S3.

2. Install the precast precast lattice beam (1) above the mortar cushion layer (18), leaving a square overlapping area between the left and right cross beams and the upper and lower vertical beams, and forming a cross overlapping joint (2) with the stepped joint (103) of the precast lattice beam (1); S3.

3. The top of the vertical beam extends into the slope top beam (1001), and the bottom of the vertical beam extends into the slope bottom beam (1002); S4. Installation of the lower steel skeleton (202) of the cross overlapping joint (2): S4.

1. Drill cable holes (402) at the central parts of the square bottom plate (3) and the cross-connected top plate (404), and drill bolt holes (401), grouting holes (403) and bent reinforcement reserved holes (406) on the cross-connected top plate (404); S4.

2. Weld the square bottom plate (3) and the cross-connected top plate (404) to the upper and lower ends of the connecting cylinder body (5) respectively, and evenly weld the lower stiffening rib plates (601) around the connecting cylinder body (5) to form the lower steel skeleton (202); S4.

3. Fix the square bottom plate (3) of the lower steel skeleton (202) in the square overlapping area between the precast lattice beams (1). The bent reserved reinforcement (102) of the precast lattice beam (1) passes through the corresponding bent reinforcement reserved hole (406) of the cross-connected top plate (404), and the four side plates of the cross-connected top plate (404) overlap on the stepped joint (103) layer of the precast lattice beam (1); S5. Installation of the upper steel skeleton (201) of the cross overlapping joint (2): S5.

1. Drill cable anchor holes (402), bolt holes (401), grouting holes (403) and reserved holes for bent steel bars (406) at the central part of the cross-connecting bottom plate (405); drill matching cable anchor holes (402) and grouting holes (403) on the stressed top plate (7); S5.

2. Weld the stressed top plate (7) and the cross-connecting bottom plate (405) to the upper and lower ends of the connecting cylinder body (5) respectively, and evenly weld upper stiffening rib plates (602) around the connecting cylinder body (5) to form the upper steel skeleton (201); S5.

3. Overlap the cross-sections of the upper steel skeleton (201) cross-connecting bottom plate (405) and the lower steel skeleton (202) cross-connecting top plate (404), and fix the four side plates of the cross-connecting bottom plate (405) and the cross-connecting top plate (404) to the stepped joint (103) layer of the precast lattice girder (1) through connecting bolts (20); S6. Steel bar binding at the cross-lapped joint (2) part: Bind and extend the horizontally reserved steel bars (101) of the stepped joints (103) of the adjacent precast lattice girders (1) at the cross-lapped joint (2) part with extended steel bars (17) to form a whole; S7. Cable anchor construction and primary tensioning: Drill a cable anchor installation hole at the position of the cable anchor hole (402) of the cross-lapped joint (2), install the cable anchor into the cable anchor installation hole and grout, fix the cable anchor to the stressed top plate (7) at the top of the upper steel skeleton (201) through the anchor backing plate (9), and conduct primary tensioning with a tensioning force of 30% of the design value of tensioning, so that the precast lattice girder (1) and the cable anchor form a support system and generate an initial anchoring force; S8. Pouring of the composite concrete (203): Pour the composite concrete (203) into the gap between the precast lattice girder (1) and the steel skeleton through the grouting hole (403) to make the left and right lattice cross beams and the upper and lower lattice vertical beams form a whole; S9. Secondary tensioning of the cable anchor: Conduct secondary tensioning on the secondary tensioning cable anchor (8) to reach 100% of the design value of tensioning; S10. Backfilling and greening: The planting area (15) enclosed by the precast lattice girders (1) is backfilled with a gravel layer (12) and a planting soil layer (13) in sequence from bottom to top in layers, and greening plants (14) are planted in the planting soil layer (13).

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