Seamless expansion joint suitable for medium and small bridges

Abstract

The utility model belongs to the technical field of bridge expansion joints, and particularly relates to a seamless expansion joint suitable for medium and small bridges. The utility model provides a seamless expansion joint suitable for small and medium-sized bridges, which comprises a steel bar connecting unit arranged between a bridge body and a bridge abutment, and a filling layer poured on the steel bar connecting unit and connected with a bridge floor, the reinforcing steel bar connecting unit comprises a fixed reinforcing steel bar net of which at least one end is fixedly connected with the bridge floor, a movable reinforcing steel bar net arranged above the fixed reinforcing steel bar net, and a plurality of vertical anchoring reinforcing steel bars arranged between the fixed reinforcing steel bar net and the movable reinforcing steel bar net; the seamless expansion joint has the advantages that by the aid of the reinforcing steel bars and the filling layer, breakage caused by large cracks can be avoided, certain supporting strength can be provided, the seamless expansion joint is high in strength, toughness and durability and easy to construct due to mutual matching of the reinforcing steel bars and the filling layer, the service life of the seamless expansion joint is the same as that of a bridge main body structure, and the service life of the bridge main body structure is prolonged. The economic benefit is obvious.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge expansion joints, and in particular relates to a seamless expansion joint suitable for small and medium-sized bridges. Background Art

[0002] Expansion joints are crucial ancillary structures in bridges, primarily designed to absorb deformation of the beam. Positioned at relatively weak structures, such as beam ends, expansion joints bear the repetitive impact of vehicle loads and various external environmental influences. This coupling of load and environmental factors can easily damage the beams, slabs, and bridge deck pavement. Statistics show that approximately half of bridge failures are related to expansion joints. On urban roads, the maintenance cost of bridge expansion joints accounts for approximately 15% of road management expenses. This is why seamless expansion joints have emerged.

[0003] The Chinese utility model patent with patent announcement number CN212834971U and announcement date 2021.3.30 discloses a new type of seamless expansion device for bridges with beam end filling, including an elastic material layer cushion laid on the top surface of the abutment and located at the bottom of the gap between the main beam and the back wall, an elastic filling layer arranged along the wall surface of the back wall, and a cement-based grouting layer arranged along the end surface of the beam. The elastic filling layer is bonded to the cement-based grouting layer, and the thickness of the elastic filling layer is 8mm.

[0004] The general usage and advantages of the new type of seamless expansion and contraction device for bridges with beam end filling in this Chinese utility model patent are as follows: the asphalt and the integral concrete layer of the bridge deck are chiseled off, and a thin layer of elastic material is poured on the top surface of the abutment and at the bottom of the gap between the main beam and the back wall to construct an elastic material layer cushion. This step can ensure that the main beam can expand and contract normally during the subsequent use of the expansion and contraction device; a foam plastic plate is set along the wall surface of the back wall, and the thickness of the foam plastic plate is about 8mm; a cement-based grouting material is poured between the foam plastic plate and the end face of the beam to construct a cement-based grouting material layer; and the cement-based grouting material layer is poured. After the cement-based grouting material reaches the designed strength, the pouring construction of the integral concrete layer of the bridge is carried out; the foam plastic board is removed, cleaned and then the elastic filling material is poured on the beam end to construct an elastic filling layer; asphalt concrete is spread on the entire bridge deck, and the constructed asphalt pavement is cut and filled; the utility model can effectively adjust the gap between the beam end and the back wall and construct an elastic filling layer through the improved beam seamless expansion device, which can ensure the expansion and contraction deformation of the main beam on the one hand, and on the other hand is conducive to the stiffness connection and transition between the main beam and the back wall, thereby effectively reducing the impact effect of vehicles running on the bridge deck on the main beam.

[0005] However, during actual use, this new type of seamless expansion joint device for bridges with beam end filling still has at least the following shortcomings. In other words, these are the technical problems to be solved by the present invention: although the seamless expansion joint is constructed with an elastic filling layer to prevent the expansion joint from being damaged, there is still the problem of insufficient expansion joint strength, resulting in collapse and a short service life.

[0006] Therefore, in summary, there is an urgent need for a seamless expansion joint that is not prone to cracking and collapse to solve the problems of this type. Utility Model Content

[0007] The utility model provides a seamless expansion joint suitable for small and medium-sized bridges, including a steel bar connection unit arranged between the beam body and the abutment, a filling layer cast on the steel bar connection unit and connected to the bridge deck, the steel bar connection unit including a fixed steel bar mesh fixedly connected to the bridge deck at least one end, a movable steel bar mesh arranged above the fixed steel bar mesh, and a plurality of vertical anchor steel bars arranged between the fixed steel bar mesh and the movable steel bar mesh, so that: the utility model ensures that the seamless expansion joint can avoid large cracks and cause breakage and can also provide a certain support strength through the dual arrangement of steel bars and filling layers. The two cooperate with each other to provide a seamless expansion joint with high strength, high toughness, high durability, and easy construction, which can achieve the same service life as the main structure of the bridge and has significant economic benefits.

[0008] The technical solution adopted by the present invention to solve the above-mentioned problems is: a seamless expansion joint suitable for small and medium-sized bridges, including a steel bar connection unit arranged between the beam body and the abutment, and a filling layer cast on the steel bar connection unit and connected to the bridge deck; the steel bar connection unit includes a fixed steel mesh fixedly connected to the bridge deck at least one end, a movable steel mesh arranged above the fixed steel mesh, and a plurality of vertical anchor steel bars arranged between the fixed steel mesh and the movable steel mesh; the vertical anchor steel bars are fixedly connected to the beam body or the abutment.

[0009] A further preferred technical solution is that the filling layer is a UHPC concrete layer.

[0010] A further preferred technical solution is that it also includes a connecting plate arranged at the joint between the beam body and the abutment.

[0011] A further preferred technical solution is that the connecting plate includes two overlapping plates respectively arranged on the beam body and the abutment surface, and a connecting plate whose two ends are respectively connected to the two overlapping plates and located at the upper end of the joint.

[0012] A further preferred technical solution is that the fixed steel mesh includes first transverse fixed steel bars and first longitudinal fixed steel bars arranged perpendicular to each other to form a grid structure, and ends of the first transverse fixed steel bars are fixedly connected to the bridge deck.

[0013] A further preferred technical solution is that the movable steel mesh includes second transverse fixed steel bars and second longitudinal fixed steel bars which are arranged perpendicular to each other to form a grid structure.

[0014] A further preferred technical solution is that the vertical anchoring steel bar includes a bar body whose two ends are respectively connected to the first transverse fixed steel bar and the second transverse fixed steel bar or to the first longitudinal fixed steel bar and the second longitudinal fixed steel bar.

[0015] A further preferred technical solution is that: the vertical anchor steel bar also includes a quick connection assembly arranged at the end of the tendon; the quick connection assembly includes a slot arranged at the end of the tendon for passing the steel bar, an external threaded section arranged on the outer surface of the end of the tendon, and a limit piece screwed onto the external threaded section.

[0016] A further preferred technical solution is that the first transverse fixed steel bar includes an outer rod, two inner connecting rods slidably connected to the two ends of the outer rod and respectively connected to two adjacent bridge decks, and a temporary limiting component arranged on the outer rod for locking the position of the inner connecting rod.

[0017] A further preferred technical solution is that the temporary limiting assembly includes a plurality of through holes provided on the outer rod, a socket provided on the inner connecting rod at the inner end of the outer rod, and an insertion rod provided in the through holes and inserted into the socket.

[0018] A further preferred technical solution is that: the first transverse fixed steel bar further includes an anti-slip assembly provided at the connection between the outer rod and the inner connecting rod.

[0019] A further preferred technical solution is that the anti-slip assembly includes a closing plate arranged at the end of the outer rod, a connecting hole arranged on the closing plate, and a convex ring arranged at the end of the inner connecting rod and located inside the outer rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall schematic diagram of the utility model;

[0021] Figure 2 It is the overall front view of the utility model;

[0022] Figure 3 It is a partial structural diagram of the utility model;

[0023] Figure 4 This is a front view of the quick connection assembly of the utility model;

[0024] Figure 5This is a cross-sectional view of the first transverse fixed steel bar of the present invention.

[0025] In the figures, the meanings of the reference numerals are as follows:

[0026] Beam a, abutment b, bridge deck c;

[0027] Rebar connection unit 1, filling layer 2, connection plate 3;

[0028] Fixed steel mesh 11, movable steel mesh 12, vertical anchor steel bars 13, lap plate 31, connecting plate 32;

[0029] First transverse fixed steel bar 111, first longitudinal fixed steel bar 112, second transverse fixed steel bar 121, second longitudinal fixed steel bar 122, reinforcement body 131, quick connection assembly 132;

[0030] Outer rod 1111, inner connecting rod 1112, temporary limiting assembly 1113, anti-drop assembly 1114, slot 1321, external thread section 1322, limiting piece 1323;

[0031] Through hole 11131 , insertion hole 11132 , insertion rod 11133 , closing plate 11141 , connecting hole 11142 , and protruding ring 11143 . DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The following descriptions are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention.

[0033] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. The words "inside" and "outside" refer to the directions toward or away from the geometric center of a specific component, respectively. They are relative concepts and may therefore change accordingly according to their different positions and different usage states. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0034] Example 1

[0035] As attached Figure 1-3As shown, a seamless expansion joint suitable for small and medium-sized bridges includes a steel bar connection unit 1 arranged between a beam body a and an abutment b, and a filling layer 2 cast on the steel bar connection unit 1 and connected to the bridge deck c; the steel bar connection unit 1 includes a fixed steel mesh 11 fixedly connected to the bridge deck c at least at one end, a movable steel mesh 12 arranged above the fixed steel mesh 11, and a plurality of vertical anchor steel bars 13 arranged between the fixed steel mesh 11 and the movable steel mesh 12; the vertical anchor steel bars 13 are fixedly connected to the beam body a or the abutment b.

[0036] In this embodiment, the general method of using the seamless expansion joint is as follows:

[0037] The filling layer 2 is a concrete layer made of ultra-high toughness concrete, which is used to fill the expansion joint. A double-layer steel mesh is arranged in the filling layer 2, wherein the bottom steel mesh is a fixed steel mesh 11 fixedly connected to the concrete layer of the bridge deck c on the beam a, providing strength support for the expansion joint. The movable steel mesh 12 is connected to the fixed steel mesh 11 through the vertical anchor steel bar 13, and is located above the fixed steel mesh 11 and connected to the asphalt layer or pavement layer of the bridge deck c. It has a certain range of movement, further increasing the support strength. The lower end of the vertical anchor steel bar 13 extends into the beam body or the abutment; ultra-high toughness concrete is used as It is a filling material for expansion joints, which has the characteristics of high strength and can adapt to the complex use environment of expansion joints and withstand repeated impacts of heavy-loaded vehicles. It avoids the problems of local sinking, aging of filling materials, rutting and other problems of traditional seamless expansion joint fillers. In addition, ultra-high toughness concrete also has the advantage of high durability and can achieve the same life cycle as the main structure of the bridge. During the service period, only maintenance and upkeep of the expansion joints are required, which has significant economic benefits. Furthermore, ultra-high toughness concrete does not require special construction auxiliary tools, but only conventional steel bars and concrete construction, and has the advantages of convenient construction and easy quality control.

[0038] As a preference of this embodiment, the filling layer 2 is a UHPC concrete layer.

[0039] In this embodiment, UHPC is a material with ultra-high durability and mechanical properties. It has a toughness 250 times greater than that of ordinary concrete. It can effectively avoid the occurrence of large cracks, evenly disperse external forces to balance the pressure on the expansion joint, and extend the service life.

[0040] As a preferred embodiment of this embodiment, the seamless expansion joint also includes a connecting plate 3 arranged at the joint between the beam body a and the abutment b; the connecting plate 3 includes two lap plate bodies 31 respectively arranged on the surface of the beam body a and the abutment b, and a connecting plate body 32 at both ends respectively connected to the two lap plate bodies 31 and located at the upper end of the joint.

[0041] In this embodiment, the connecting plate 3 is used to connect the gap between the beam body a and the abutment b, and to carry the ultra-high toughness concrete to form a filling layer. In order to avoid dimensional changes at the connection point, the connecting plate 3 includes a lap plate body 31 and a connecting plate body 32. The connecting plate body 32 is configured as an arc plate or an elastic plate to balance and absorb the deformation caused by the expansion and contraction of the expansion joint.

[0042] As a preferred embodiment of this embodiment, the fixed steel mesh 11 includes a first transverse fixed steel bar 111 and a first longitudinal fixed steel bar 112 arranged perpendicularly to each other to form a grid structure, and the end of the first transverse fixed steel bar 111 is fixedly connected to the bridge deck c; the movable steel mesh 12 includes a second transverse fixed steel bar 121 and a second longitudinal fixed steel bar 122 arranged perpendicularly to each other to form a grid structure.

[0043] In this embodiment, the first transverse fixed steel bar 111 of the fixed steel mesh 11 is connected to the bridge deck c on the beam body a to provide strength, and the first longitudinal fixed steel bar 112 is arranged perpendicular to the first transverse fixed steel bar 111 to form a grid to expand the support surface. Similarly, the movable steel mesh 12 also includes a second transverse fixed steel bar 121 and a second longitudinal fixed steel bar 122. The second transverse fixed steel bar 121 is connected to the asphalt layer or pavement layer of the bridge deck c.

[0044] Compared with the existing technology, the technical solution described in this embodiment has the following advantages: through the dual combination of steel bars and ultra-high toughness concrete, a seamless expansion joint structure with both supporting strength and certain toughness is provided, and it has the characteristics of convenient and efficient construction and easy maintenance in the later stage.

[0045] Example 2

[0046] The difference between this embodiment and the first embodiment is that a quick connection component is added to the end of the vertical anchor steel bar, as shown in the attached Figure 4 As shown, the details are as follows:

[0047] The vertical anchoring steel bar 13 includes a steel body 131 whose two ends are respectively connected to the first transverse fixed steel bar 111 and the second transverse fixed steel bar 121 or to the first longitudinal fixed steel bar 112 and the second longitudinal fixed steel bar 122, and a quick connection component 132 arranged at the end of the steel body 131; the quick connection component 132 includes a slot 1321 arranged at the end of the steel body 131 for passing the steel bar, an external thread section 1322 arranged on the outer surface of the end of the steel body 131, and a limit piece 1323 screwed on the external thread section 1322.

[0048] In this embodiment, both ends of the vertical anchoring steel bar 13 body 131 are connected to the transverse steel bars (the first transverse fixed steel bar 111 and the second transverse fixed steel bar 121) or both ends are connected to the longitudinal steel bars (the first longitudinal fixed steel bar 112 and the second longitudinal fixed steel bar 122), and a quick connection component 132 is provided at the end, so that the fixed steel mesh 11 and the movable steel mesh 12 remain parallel while allowing relative movement within a certain range to adapt to the changes in the expansion joint. The vertical anchoring steel bars are arranged in the same direction to ensure that the movable steel mesh 12 has greater mobility, which is advantageous. A quick connection assembly 132 is selected to be set at the upper end of the vertical anchor steel bar 13 to provide greater stability; the second transverse fixed steel bar 121 or the second longitudinal fixed steel bar 122 passes through the slot 1321 of the quick connection assembly 132, and then the position of the limiter 1323 on the external threaded section 1322 is moved to prevent the steel bar from falling out of the slot 1321 and separating from the steel body 131. The steel bar can slide in the slot 1321 and can adapt well to the changes in the expansion joint. There is no need for complicated welding and bundling during the construction process, which is efficient and convenient; the limiter 1323 is preferably a nut.

[0049] Compared with the existing technology, the technical solution described in this embodiment has the advantages of accelerating the efficiency of on-site construction through the structural setting of vertical anchoring steel bars, and providing a certain range of movement for the movable steel mesh to better adapt to changes in expansion joints.

[0050] Example 3

[0051] The difference between this embodiment and the first and second embodiments is that the first transverse fixed steel bar is a retractable structure. Figure 5 As shown, the details are as follows:

[0052] The first transverse fixed steel bar 111 includes an outer rod 1111, two inner connecting rods 1112 slidably connected to the two ends of the outer rod 1111 and respectively connected to the two adjacent bridge decks c, and a temporary limiting component 1113 arranged on the outer rod 1111 for locking the position of the inner connecting rod 1112.

[0053] In this embodiment, the two ends of the first transverse reinforcement 111 used to form the fixed reinforcement mesh 11 are respectively fixed to the beam body and the abutment. In order to better adapt to the changes in the expansion joint, the first transverse reinforcement is preferably a retractable structure; the two ends of the outer rod 1111 are respectively connected to the two inner connecting rods 1112, and the other ends of the two inner connecting rods 1112 are respectively connected to the beam body and the abutment. The length of the first transverse fixed reinforcement 111 is changed by changing the position of the inner connecting rod 1112 in the outer rod 1111. In order to avoid instability caused by changes in the length of the reinforcement during the pouring process, the length of the first transverse fixed reinforcement 111 can be locked by a temporary limiting component 1113 during construction, and then released after it is fixedly connected to the beam body and the abutment.

[0054] As a preferred embodiment of this embodiment, the temporary limiting assembly 1113 includes a plurality of through holes 11131 arranged on the outer rod 1111, a socket 11132 arranged on the inner connecting rod 1112 at the inner end of the outer rod 1111, and an insertion rod 11133 arranged in the through hole 11131 and inserted into the socket 11132.

[0055] In this embodiment, the length of the first transverse reinforcement 111 is locked by inserting the insertion rod 11133 into the insertion hole 11132 on the inner connecting rod 1112 through the through hole 11131 on the outer rod 1111, which is convenient for subsequent construction. After the reinforcement is built, the insertion rod 11133 is pulled out for pouring. The insertion rod 11133 is preferably an L-shaped rod, which further enhances the stability of the locking.

[0056] As a preferred embodiment of this embodiment, the first transverse fixed steel bar 111 also includes an anti-slip component 1114 arranged at the connection between the outer rod 1111 and the inner connecting rod 1112; the anti-slip component 1114 includes a closing plate 11141 arranged at the end of the outer rod 1111, a connecting hole 11142 arranged on the closing plate 11141, and a convex ring 11143 arranged at the end of the inner connecting rod 1112 and located inside the outer rod 1111.

[0057] In this embodiment, in order to prevent the outer rod 1111 and the inner rod 1112 from detaching during the extension and retraction process, resulting in structural failure, an anti-detachment component 1114 is provided at the connection between the two; the two end ports of the outer rod 1111 are sealed with a closing plate 11141, and the closing plate 11141 is provided with a connecting hole 11142 with an inner diameter slightly larger than the rod diameter of the inner rod 1112 to ensure that the inner rod 1112 can slide smoothly on the closing plate 11141, and the outer diameter of the convex ring 11143 at the end of the inner rod 1112 located inside the outer rod 1111 is larger than the inner diameter of the connecting hole 11142 and smaller than the inner diameter of the outer rod 1111, so as to prevent the inner rod 1112 from detaching from the end of the outer rod 1111.

[0058] Compared with the existing technology, the technical solution described in this embodiment has the advantages of providing strength and toughness while more flexibly adapting to changes in expansion joints through simple structure and convenient operation, greatly improving the efficiency of installing steel bars at the construction site, and improving the stability of the overall device.

[0059] This application uses a 1×16m simply supported beam bridge that has been implemented to illustrate the specific operation of the seamless expansion joint described in this application. The superstructure is a prefabricated low T, and the abutments are column-type abutments, including the following steps:

[0060] In the first step, during the construction of the beam a and abutment b, vertical anchor steel bars 13 are pre-embedded on the top surface of the beam a and the top surface of the back wall of the abutment b to ensure better connection between the expansion joint filling layer 2 and the beam a and abutment b;

[0061] In the second step, during the construction of the bridge deck c pavement, a fixed steel mesh 11 is embedded in the concrete pavement layer, and a space corresponding to the structural dimensions of the expansion joint is reserved. The side surface of the bridge deck c pavement layer connected to the expansion joint, the top surface of the beam a, and the top surface of the back wall of the abutment b should be roughened;

[0062] The third step is to construct the movable steel mesh 12 and arrange the connecting plate 3 at the joint between the beam a and the back wall of the abutment b;

[0063] The fourth step is to pour the expansion joint filler to construct the filling layer 2, and ensure that the expansion joint is flush with the bridge deck c pavement layer, and then the maintenance is completed.

[0064] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications are possible within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. These modifications are non-inventive and are protected by patent law as long as they fall within the scope of the claims of the present invention.

Claims

1. A seamless expansion joint suitable for small and medium-sized bridges, characterized by: The invention comprises a steel bar connection unit (1) arranged between a beam body (a) and a bridge abutment (b), and a filling layer (2) cast on the steel bar connection unit (1) and connected to a bridge deck (c); the steel bar connection unit (1) comprises a fixed steel bar mesh (11) at least one end of which is fixedly connected to the bridge deck (c), a movable steel bar mesh (12) arranged above the fixed steel bar mesh (11), and a plurality of vertical anchor steel bars (13) arranged between the fixed steel bar mesh (11) and the movable steel bar mesh (12); the vertical anchor steel bars (13) are fixedly connected to the beam body (a) or the bridge abutment (b).

2. The seamless expansion joint suitable for small and medium-sized bridges according to claim 1, characterized in that: The filling layer (2) is a UHPC concrete layer.

3. The seamless expansion joint suitable for small and medium-sized bridges according to claim 1, characterized in that: It also includes a connecting plate (3) arranged at the joint between the beam body (a) and the abutment (b).

4. The seamless expansion joint suitable for small and medium-sized bridges according to claim 3, characterized in that: The connecting plate (3) comprises two overlapping plate bodies (31) respectively arranged on the surface of the beam body (a) and the abutment (b), and a connecting plate body (32) at both ends respectively connected to the two overlapping plate bodies (31) and located at the upper end of the joint.

5. The seamless expansion joint suitable for small and medium-sized bridges according to claim 1, characterized in that: The fixed steel mesh (11) comprises first transverse fixed steel bars (111) and first longitudinal fixed steel bars (112) arranged perpendicularly to each other to form a grid structure, and the ends of the first transverse fixed steel bars (111) are fixedly connected to the bridge deck (c).

6. The seamless expansion joint suitable for small and medium-sized bridges according to claim 5, characterized in that: The movable steel mesh (12) comprises second transverse fixed steel bars (121) and second longitudinal fixed steel bars (122) arranged perpendicularly to each other to form a grid structure.

7. The seamless expansion joint suitable for small and medium-sized bridges according to claim 6, characterized in that: The vertical anchoring steel bar (13) comprises a steel bar body (131) whose two ends are respectively connected to the first transverse fixing steel bar (111) and the second transverse fixing steel bar (121) or to the first longitudinal fixing steel bar (112) and the second longitudinal fixing steel bar (122).

8. The seamless expansion joint suitable for small and medium-sized bridges according to claim 7, characterized in that: The vertical anchoring steel bar (13) further comprises a quick connection assembly (132) arranged at the end of the steel bar (131); the quick connection assembly (132) comprises a slot (1321) arranged at the end of the steel bar (131) for passing the steel bar, an external thread segment (1322) arranged on the outer surface of the end of the steel bar (131), and a stopper (1323) screwed onto the external thread segment (1322).

9. The seamless expansion joint suitable for small and medium-sized bridges according to claim 8, characterized in that: The first transverse fixed steel bar (111) comprises an outer rod (1111), two inner connecting rods (1112) slidably connected to the inner ends of the outer rod (1111) and respectively connected to two adjacent bridge decks (c), and a temporary limiting assembly (1113) provided on the outer rod (1111) for locking the position of the inner connecting rod (1112).

10. The seamless expansion joint suitable for small and medium-sized bridges according to claim 9, characterized in that: The temporary limiting assembly (1113) comprises a plurality of through holes (11131) provided on the outer rod (1111), a socket (11132) provided on the inner connecting rod (1112) at the inner end of the outer rod (1111), and an insertion rod (11133) provided in the through holes (11131) and inserted into the socket (11132).

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