Split type bent cap

Abstract

The utility model discloses a split type bent cap, belongs to the field of bridge engineering, and solves the bottleneck problems in the aspects of weight, precision, efficiency, durability and the like in the traditional bent cap construction. The utility model mainly solves the bottleneck problems in the aspects of weight, precision, efficiency, durability and the like in the traditional capping beam construction, and provides a key technical path for industrialization and greenization transformation of bridge engineering. According to the utility model, the traditional integral bent cap is transformed into a split structure, and the bent cap is modularized into a plurality of standardized light bent cap units, so that the dependence on hoisting equipment is greatly reduced. The bent cap units are connected into a whole through the energy dissipation tie bars, so that the bent cap only bears hogging moment, the problem that a traditional bent cap is prone to cracking is solved, the energy dissipation characteristic is reduced through the energy dissipation tie bars, the problem of midspan deformation of the traditional bent cap is solved, and the anti-seismic function is achieved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to bridge engineering field, and concretely relates to a split type bent cap. BACKGROUND

[0002] With the development of bridge engineering towards high efficiency and assembly, the application of traditional prefabricated reinforced concrete bent cap in the substructure gradually exposes significant limitations. At present, the integral prefabrication is mostly used for bent cap, which is limited by the characteristics of concrete material. The self-weight of the bent cap is too large, resulting in high transportation and hoisting cost. Especially in complex terrains such as mountains and rivers, heavy components put strict requirements on the bearing capacity of temporary support and equipment performance. Even the cast-in-place process is forced to be used due to site conditions, which seriously restricts the construction efficiency. At the same time, the traditional bent cap has very high installation precision requirements, and uncontrollable factors such as site foundation positioning deviation and splicing error can easily cause component misplacement, which not only affects the structural stress performance, but also requires additional manpower for adjustment, further increasing the construction period and cost. In addition, the production, transportation and installation of large prefabricated components rely on intensive resource input, which is difficult to continue under the background of tightening environmental protection requirements and engineering intensification development. In view of the above problems, the ultra-high performance concrete (UHPC) provides a new path for the lightweight and performance improvement of the bent cap due to its high strength, light weight and strong durability. However, single UHPC prefabricated bent cap still faces problems such as too large overall size and complex node connection. SUMMARY

[0003] The utility model aims to provide a split type bent cap, mainly solves the bottleneck problems of traditional bent cap construction in weight, precision, efficiency and durability, and provides a key technical path for the industrialization and green transformation of bridge engineering.

[0004] The technical scheme of the utility model is: a split type bent cap, comprising a plurality of bent cap units, the plurality of bent cap units are arranged side by side along the transverse direction of the bridge, the adjacent bent cap units are connected through energy dissipation ties, the lower surface of the bent cap unit is provided with a socket hole, and the upper surface of the bent cap unit is provided with a cast-in-place slot, and the cast-in-place slot is communicated with the socket hole.

[0005] As a further improvement of the utility model, the bent cap unit is prefabricated by C60 concrete with pretensioning prestress, and the top of the bent cap unit is provided with prestressed steel strand.

[0006] As a further improvement of the utility model, the end of the bent cap unit is provided with a pre-embedded anchor, and the energy dissipation tie is connected to the pre-embedded anchor through a fixing bolt.

[0007] As a further improvement of the utility model, the adjustable tensioning mechanism comprises an adjusting hole, an adjusting bolt and a lock washer, the adjusting hole is arranged on the embedded anchor, and the energy dissipation link is fastened to the adjusting hole through the adjusting bolt and the lock washer.

[0008] As a further improvement of the utility model, the socket hole is a cavity with a small upper part and a large lower part, the outer periphery of the bottom of the socket hole is provided with a containing groove, and the bottom of the socket hole is a resting surface.

[0009] As a further improvement of the utility model, the inner wall of the socket hole is provided with a key tooth groove.

[0010] As a further improvement of the utility model, the key tooth groove adopts a spiral key tooth groove in a spiral line shape or an annular key tooth groove in a concave-convex tooth shape.

[0011] As a further improvement of the utility model, the top of the bent cap unit is provided with a cushion stone, steel stoppers are arranged at the outermost sides of the cushion stones on the two side bent cap units, and the steel stoppers are located at the inner side positions of the cushion stones.

[0012] The utility model has the advantages of:

[0013] 1. The utility model transforms the traditional integral bent cap into a split structure, modularizes the bent cap into a plurality of standardized light-weight bent cap units, realizes a refined construction mode of "factory prefabrication - split transportation - on-site rapid assembly", and has the advantages of reducing the weight of a single piece by more than 60%, greatly reducing the dependence on hoisting equipment, adjusting and adapting to complex foundation conditions through modularization, improving the construction fault tolerance, and providing an innovative solution with economic and reliable properties for the assembly of the bridge lower structure.

[0014] 2. The utility model connects the bent cap units into one through the energy dissipation link, so that the bent cap of the utility model only bears the negative bending moment, solves the problem of easy cracking of the traditional bent cap, reduces the energy dissipation characteristics through the energy dissipation link, avoids the problem of mid-span deformation of the traditional bent cap, and realizes the anti-seismic function. The energy dissipation link has a multi-stage energy dissipation protection mechanism and replaceable energy dissipation components. Under medium and small earthquakes, the energy dissipation link mainly bears the axial tensile and compressive forces, only elastically deforms, and maintains the normal use function of the structure; under a major earthquake, the energy dissipation link is directionally yielded at the bolt connection position at the root, dissipates energy through the formation of a plastic hinge area; after a strong earthquake, if the energy dissipation link or the bolt connection position is deformed beyond the limit, the local part can be replaced without the need to remove the whole structure, and rapid repair can be realized.

[0015] 3. The length of the energy dissipation link in the utility model can be adjusted according to the requirements on site, has stronger flexibility and a wider application range. The utility model can also be used for the widening of existing bridges, and the bent cap units can be connected to the existing bent cap through the energy dissipation link.

[0016] 4. The cap beam unit in the utility model adopts the pre-tensioning method prestress prefabrication, compared with the traditional post-tensioning method, the quality is easier to control, and the loss of prestress is also easier to control, and one process of the on-site construction is reduced, and the construction period is shortened.

[0017] 5. The utility model discloses an adjustable tensioning mechanism, when installing the energy dissipation tie bar, the fine adjustment of the installation position and the installation angle of the energy dissipation tie bar can be realized by adjusting the position of the adjusting bolt in the adjusting hole, so as to eliminate the construction error and improve the installation precision.

[0018] 6. The utility model discloses the key tooth groove is set in the socket hole inner wall, compared with the traditional socket process, the utility model greatly promotes the shear capacity and integrity of pier beam joint, realizes the synergistic optimization of key tooth groove structure and grouting process, and is suitable for high intensity earthquake area bridge.

[0019] 7. The utility model discloses the construction method is simple, does not need the on-site welding, reduces the construction difficulty. After the connecting steel bar reserved at the pier top of the bridge pier is inserted into the cap beam socket hole, through the grouting high-strength concrete consolidation, quick installation can be realized. DETAILED DESCRIPTION

[0020] Figure 1 It is the three-dimensional structure schematic diagram of the split type cap beam of the utility model;

[0021] Figure 2 It is the elevation structure schematic diagram of the split type cap beam of the utility model;

[0022] Figure 3 It is the structure schematic diagram of the adjustable tensioning mechanism in the utility model;

[0023] Figure 4 It is the structure schematic diagram of the rest surface in the utility model;

[0024] Figure 5 It is the structure schematic diagram of the spiral key tooth groove in the utility model;

[0025] Figure 6 It is the structure schematic diagram of the concave-convex key tooth groove in the utility model;

[0026] Figure 7 It is the side view structure schematic diagram of the split type cap beam of the utility model;

[0027] Figure 8 It is the construction schematic diagram of the split type cap beam of the utility model;

[0028] Figure 9 It is the bending moment envelope diagram of the split type cap beam of the utility model under the action of earthquake;

[0029] Figure 10 It is the bending moment envelope diagram of the traditional integral type cap beam under the action of earthquake.

[0030] In the figure, 1 - cap beam unit; 2 - energy dissipation tie; 3 - socket hole; 4 - cast-in-place slot; 5 - pre-embedded anchor; 6 - key tooth groove; 7 - fixing bolt; 8 - adjusting bolt; 9 - adjusting hole; 10 - lock washer; 11 - containing groove; 12 - pier; 13 - cushion stone; 14 - rubber support; 15 - steel stopper; 16 - connecting steel bar; 17 - prestressed steel strand; 18 - resting surface; 19 - inclined surface. DETAILED DESCRIPTION

[0031] The utility model will be further explained in detail below in combination with the drawings and specific embodiments.

[0032] Embodiment 1,

[0033] As Figures 1-5 shown, a split cap beam comprises a plurality of cap beam units 1, the plurality of cap beam units 1 are arranged side by side along the transverse bridge direction, adjacent cap beam units 1 are connected through steel energy dissipation ties 2, a socket hole 3 is formed in the lower surface of the cap beam unit 1, a cast-in-place slot 4 is formed in the upper surface of the cap beam unit 1, and the cast-in-place slot 4 is in communication with the socket hole 3. The cast-in-place slot 4 can be used as a pouring opening or an exhaust opening.

[0034] In this embodiment, the cap beam unit 1 is provided with two.

[0035] The cap beam unit 1 is made of C60 concrete and is precast by the pretensioning method, and the prestressed steel strand 17 is arranged at the top of the cap beam unit 1. The cap beam of the utility model serves as a substructure, the amount of prestress can be reduced, and the stress system of the cap beam of the utility model is a full negative bending distance stress system, which is different from the positive and negative bending moment alternate stress system of the traditional integral cap beam, so the prestressed steel strand 17 only needs to be arranged at the top. In this embodiment, the main beam is a UHPC light I-beam, which is a lightweight and high-strength structure, and the weight is about 50% of the weight of the traditional small box beam structure. The main beam and the cap beam of the utility model form a stiffness matching system.

[0036] The end of the cap beam unit 1 is provided with a pre-embedded anchor 5, and the energy dissipation tie 2 is connected to the pre-embedded anchor 5 through a fixing bolt 7. The pre-embedded anchor 5 is made of fatigue-resistant steel.

[0037] It also comprises an adjustable tensioning mechanism, which comprises an adjusting hole 9, an adjusting bolt 8 and a lock washer 10, the adjusting hole 9 is formed in the pre-embedded anchor 5, and the energy dissipation tie 2 is fastened and connected to the adjusting hole 9 through the adjusting bolt 8 and the lock washer 10. In this embodiment, the adjusting hole 9 is a cross-shaped hole.

[0038] The socket hole 3 is a cavity with a small upper part and a large lower part, which can effectively reduce the difficulty of separation of the built-in core mold when the precast cap beam is built, and can save the amount of cast-in-place concrete at the construction site. The bottom of the socket hole 3 is provided with a receiving groove 11, and the bottom of the socket hole 3 is a resting surface 18. The pier 12 extends into the receiving groove 11, and the resting surface 18 rests on the top of the pier 12. On the one hand, the receiving groove 11 can accommodate piers 12 of different diameters. In the embodiment, it can adapt to 1.0m~1.1m diameter piers, and can adapt to the position deviation during installation. On the other hand, the receiving groove 11 can also play a role in exhausting air when pouring concrete in the socket hole 3.

[0039] The inner wall of the socket hole 3 is provided with a key tooth groove 6. The key tooth groove 6 is a spiral key tooth groove in a spiral line as shown in Figure 5 , and its cross section is a trapezoidal shape, or a concave-convex tooth-shaped annular key tooth groove as shown in Figure 6 , and its cross section is a rectangular shape.

[0040] The cap beam unit 1 is provided with a cushion stone 13 on the top, and a rubber support 14 is arranged on the cushion stone 13. Steel stoppers 15 for preventing beam falling are arranged on the sides of the outermost cushion stones 13 of the cap beam units 1 on both sides, and the steel stoppers 15 are located inside the cushion stones 13 to facilitate shortening the length of the cap beam unit 1, reducing the weight of the cap beam unit 1, and facilitating hoisting construction. Compared with the traditional concrete stopper, the steel stopper 15 has a better energy consumption mechanism, the steel material has self-restoring force, and can restore to its original state after impact, and can withstand repeated impact.

[0041] The cap beam of the utility model is a full negative bending moment force structure, therefore, the lower section of the cap beam unit 1 is provided with an inward converging inclined surface 19 to reduce the amount of concrete at the positive bending moment, reduce the dead weight, and make the structure more solid and more economical.

[0042] A construction method of a split type cap beam, comprising the following steps:

[0043] A, the pier 12 top is reserved with a connecting steel bar 16, as shown in Figure 8 ;

[0044] B, the cap beam unit 1 is hoisted to above the pier 12, and then slowly lowered, so that the connecting steel bar 16 is inserted into the socket hole 3 and the resting surface 18 rests on the top of the pier 12;

[0045] C, after the insertion and installation of each cap beam unit 1 are completed, the cap beam units 1 are connected in sequence through the energy consumption tie rod 2. When connected, the position of the adjusting bolt 8 in the adjusting hole 9 is adjusted first, so that the installation position and angle of the energy consumption tie rod are finely adjusted, and then the adjusting bolt 8 is fastened by cooperating with the lock washer 10 to realize preliminary positioning, and then the energy consumption tie rod 2 and the pre-buried anchor 5 are punched and installed with the fixing bolt 7;

[0046] D, after the connection between the cap beam units 1 is completed, high-strength concrete is poured into the socket hole 3 through the cast-in-place slot 4, the cap beam unit 1 is connected with the pier 12 as a whole, and the containing groove 11 is blocked.

[0047] The utility model discloses a traditional integral cap beam is reformed into split type structure, and traditional entity pouring structure is replaced by energy dissipation tie bar 2, so as to reduce the concrete consumption, reduce hoisting weight and save cost. Energy dissipation tie bar 2 not only plays the role of connecting cap beam unit 1, but also can be used as an anti-seismic energy dissipation component, and the anti-seismic performance of the cap beam is improved.

[0048] The following compares the bending moment envelope diagram of the split type cap beam of the utility model under the action of earthquake (Fig. Figure 9 ) and the bending moment envelope diagram of the traditional integral cap beam under the action of earthquake (Fig. Figure 10 ), unit kN·m. As shown in Fig. Figure 9 , Figure 10 Under the action of the same earthquake, the maximum bending moment of the top of the traditional integral cap beam is 359.5 kN·m, the maximum bending moment of the top of the pier is 175.5 kN·m, and the maximum bending moment of the pier bottom is 142.4 kN·m; after the split type cap beam with energy dissipation tie bar 2 is adopted, the maximum bending moment of the top of the cap beam is 321.2 kN·m, the internal force reduction amplitude is 10.7%, the maximum bending moment of the top of the pier is 39.4 kN·m, the internal force reduction amplitude is 77.5%, and the maximum bending moment of the pier bottom is 124.1 kN·m, and the internal force reduction amplitude is 12.9%.

[0049] The above data prove that, under the same conditions,

[0050] (1) the split type cap beam of the utility model adopts energy dissipation tie bar 2, the stiffness of the cap beam in the middle of the span is weakened, the bending moment peak value is shifted to both sides of the pier top, the bending moment redistribution effect is generated, the cap beam only appears negative bending distance, and simultaneously, the layout of the prestressed steel strand 17 forms a cooperative bending resistance mechanism, and the maximum peak value of the negative bending distance is effectively reduced.

[0051] (2) the split type cap beam of the utility model actively adjusts the load transmission path through the axial tension and compression deformation of the energy dissipation tie bar 2, the bending moment of the top of the pier is greatly reduced, the plastic hinge of the top of the pier can be avoided, and the seismic safety reserve of the pier column is greatly improved.

[0052] (3) the split type cap beam of the utility model reduces the bending moment of the bottom of the pier, which indicates that the seismic energy is deformed and dissipated by the energy dissipation tie bar 2 and the pier itself, instead of being resisted and absorbed by the pier alone, according to the fact that the yield point of the energy dissipation tie bar 2 is lower than the pier characteristics, the energy dissipation tie bar 2 yields preferentially under the action of strong earthquake, a plastic hinge area is formed to further dissipate energy, and the "multi-stage energy dissipation" concept is verified.

Claims

1. A split deck, characterized by: The utility model provides a kind of energy dissipation beam unit, including multiple cap beam units (1), multiple cap beam units (1) are arranged side by side along cross-bridge direction, and adjacent cap beam units (1) are connected by energy dissipation tie bar (2), and the lower surface of cap beam unit (1) is provided with socket hole (3), and the upper surface of cap beam unit (1) is provided with cast-in-place slot (4), and cast-in-place slot (4) is communicated with socket hole (3).

2. The split deck girder according to claim 1, wherein: The cap beam unit (1) is prefabricated by C60 concrete with pretensioning method prestress, and the top of the cap beam unit (1) is provided with prestressed steel strand (17).

3. The split deck girder according to claim 1 or 2, wherein: The end of the cap beam unit (1) is provided with embedded anchor (5), and the energy dissipation tie bar (2) is connected on the embedded anchor (5) by fixing bolt (7).

4. The split deck girder according to claim 3, wherein: It also includes adjustable tensioning mechanism, adjustable tensioning mechanism includes adjusting hole (9), adjusting bolt (8) and lock washer (10), adjusting hole (9) is opened on embedded anchor (5), and the energy dissipation tie bar (2) is fastened and connected in adjusting hole (9) by adjusting bolt (8) and lock washer (10).

5. The split deck girder according to claim 4, wherein: The socket hole (3) is a cavity with a small upper part and a large lower part, the bottom of the socket hole (3) is provided with a receiving groove (11), and the bottom of the socket hole (3) is a resting surface (18).

6. The split deck girder according to claim 5, wherein: The inner wall of the socket hole (3) is provided with a key tooth groove (6).

7. The split deck girder according to claim 6, wherein: The key tooth groove (6) is a spiral key tooth groove in spiral line shape, or a ring-shaped key tooth groove in concave-convex tooth shape.

8. The split deck girder according to claim 7, wherein: The top of the cap beam unit (1) is provided with a cushion stone (13), and a steel stopper (15) is arranged beside the outermost cushion stone (13) of the cap beam unit (1) on both sides, and the steel stopper (15) is located inside the cushion stone (13).

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