Steel-UHPC (Ultra High Performance Concrete) combined bridge deck based on combined tenon connecting pieces and construction method thereof

Abstract

The invention relates to a steel-UHPC combined bridge deck based on combined tenon connecting pieces and a construction method of the steel-UHPC combined bridge deck. The steel-UHPC combined bridge deck comprises a steel bridge deck slab, a steel tenon plate, a reinforcing mesh and a UHPC thin layer. The steel tenon plate is vertically fixed to the top face of the steel bridge deck, and the top of the steel tenon plate is provided with a tenon-shaped unit protruding upwards. The steel bridge deck slab is covered with the reinforcing mesh, and the tenon-shaped units are inserted into grids of the reinforcing mesh and fixed to the grids. UHPC concrete is poured on the steel bridge deck, the steel tenon plate and the reinforcing mesh to form a UHPC thin layer. The novel combined tenon connecting piece is applied, the limiting requirement of a UHPC thin layer on the height of the connecting piece can be met, the shearing resistance, the pulling resistance and the rigidity are higher, the number of the connecting pieces is small, the number of single pieces is small, the number of welding spots is small, the deformability in the UHPC is higher, it is ensured that the steel bridge deck and the UHPC are tightly combined, and the long-term use performance is better.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge construction, and in particular to a steel-UHPC composite bridge deck based on a composite tenon connector and a construction method thereof. Background Art

[0002] Orthotropic steel bridge decks have become the main bridge deck form for long-span bridges due to their advantages such as light weight, convenient construction and strong bearing capacity. However, in the face of the growing demand for heavy-load traffic, orthotropic steel bridge decks are prone to fatigue cracks and pavement damage during operation due to problems such as low local stiffness, complex detailed structure, poor welding quality, poor fatigue performance of U-rib single-sided fillet welds, stress concentration at the diaphragm through-holes, and low bonding strength between the steel bridge deck and the pavement. The fatigue cracks mainly occur at the connection between the top plate and the U rib and the connection between the U rib and the diaphragm (accounting for more than 90% of the total cracks).

[0003] In order to overcome the above difficulties, the industry has proposed an improved orthotropic steel-UHPC composite bridge deck, that is, welding bolts on the top of the orthotropic steel bridge deck to combine it with a thin layer of ultra-high performance concrete (UHPC) to form a bolt-connected U-rib lightweight composite bridge deck. Compared with traditional orthotropic steel bridge decks, thanks to the characteristics of UHPC's light weight, high strength and good durability, this lightweight composite bridge deck has greatly improved the local stiffness of the bridge deck while maintaining its own weight and cost, reduced the fatigue stress at the connection between the top plate and the U rib, and significantly extended the fatigue life of the bridge. In addition, as a cement-based material, UHPC has a high bonding strength with the bridge deck pavement layer, which effectively reduces the frequent damage of the pavement layer under the coupling of heavy loads, high temperatures, rainwater, etc., and reduces the cost of bridge deck pavement repairs. At present, bolt-connected U-rib lightweight composite bridge decks have been widely used in long-span bridges.

[0004] However, although the bolted U-rib lightweight composite bridge deck has largely avoided fatigue cracking and pavement damage at the connection between the top plate and the U-rib during operation, there are still the following deficiencies in actual application: First, even if the U-rib welding process is optimized, the weld quality cannot be effectively improved, and the weld eccentricity problem is difficult to solve. Second, this type of bridge deck only reduces the fatigue stress at the connection between the bridge deck and the U-rib, but the fatigue performance at other locations such as the diaphragm through-hole is slightly improved, and the fatigue problem at these locations has not been effectively controlled. Third, due to the limitation of the UHPC thin layer on the height of the connector, this type of bridge deck mostly uses small-sized bolts as connectors, and the shear, pull-out strength and stiffness of small-sized bolts are low. In order to ensure the close combination of steel and UHPC, the bolts need to be densely arranged, resulting in large workload, high difficulty, low construction efficiency, poor UHPC casting quality and high labor costs for on-site welding. Finally, during long-term use, small-sized bolts may be affected by temperature changes and load cycles and their pull-out and shear stiffness may decrease, leading to relative slip and debonding at the interface between the steel bridge deck and UHPC, further affecting the overall structural performance.

[0005] Therefore, it is necessary to propose new measures to overcome the above-mentioned defects. Summary of the invention

[0006] The object of the present invention is to provide a steel-UHPC composite bridge deck based on a composite tenon connector and a construction method thereof, so as to solve the above-mentioned problems existing in the prior art.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A steel-UHPC composite bridge deck based on a composite tenon connector, the steel-UHPC composite bridge deck comprising a steel bridge deck, a steel tenon plate, a steel mesh and a UHPC thin layer;

[0009] The steel tenon plate is vertically fixed to the top surface of the steel bridge deck, and the top of the steel tenon plate has a tenon-shaped unit protruding upward;

[0010] The steel mesh covers the top of the steel bridge deck, and the tenon-shaped units are inserted into the grid of the steel mesh and fixed to each other;

[0011] UHPC concrete is poured on the steel bridge deck, the steel tenon plate and the steel mesh to form the UHPC thin layer.

[0012] Furthermore, the steel tenon plates are arranged longitudinally on the top surface of the steel bridge deck, and multiple steel tenon plates are arranged transversely and in parallel.

[0013] Further, the tenon-shaped units are evenly arranged longitudinally on the top of the steel tenon plate, with the top being the expanded end and the lower part being the contracted section;

[0014] There are special-shaped grooves between adjacent tenon-shaped units.

[0015] Furthermore, a plate rib is provided below the steel bridge deck, and the plate rib is vertically fixed to the bottom of the steel bridge deck.

[0016] Further, the plate ribs are arranged longitudinally at the bottom of the steel bridge deck, and a plurality of plate ribs are arranged in parallel transversely;

[0017] The plate ribs correspond to the steel tenon plates in upper and lower positions.

[0018] Furthermore, a transverse diaphragm is provided below the steel bridge deck, a vertical slot is provided on the top of the transverse diaphragm, and the plate rib is inserted downward into the slot.

[0019] Furthermore, the transverse partitions are arranged transversely, and multiple transverse partitions are arranged longitudinally and in parallel.

[0020] Furthermore, the bottom of the slot has a special-shaped hole, and the top of the special-shaped hole has upward extensions on both sides of the slot.

[0021] On the other hand, a construction method of a steel-UHPC composite bridge deck based on a composite tenon connector as described is provided, the method comprising:

[0022] The bottom surface of the steel bridge deck faces upward, and a fixed plate rib is welded at the bottom of the steel bridge deck;

[0023] Align the slots of the diaphragm with the plate ribs, thereby inserting the plate ribs into the diaphragm, and continuously welding the diaphragm, the plate ribs and the steel bridge deck;

[0024] Place the top surface of the steel bridge deck upwards, weld and fix the steel tenon plate on the top of the steel bridge deck so that the tenon-shaped unit faces upwards;

[0025] Lay the steel mesh over the steel dome plate so that the dome-shaped units are inserted into the mesh of the steel mesh;

[0026] The UHPC thin layer is formed by pouring UHPC concrete on the steel bridge deck, the steel tenon plate and the steel mesh.

[0027] Furthermore, the UHPC concrete filled in the special-shaped groove of the steel tenon plate forms a concrete tenon, and the tenon-shaped unit, the concrete tenon and the transverse steel bars of the steel mesh together form a combined tenon connector that resists interface shear force.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention provides a steel-UHPC composite bridge deck based on a composite tenon connector and a construction method thereof. The UHPC is used to greatly increase the stiffness of the bridge deck, and the redundant longitudinal closed U-ribs are optimized into longitudinal open plate ribs. The plate ribs are easier to manufacture than the U-ribs, and are welded to the steel bridge deck using double-sided fillet welds, which simplifies the welding process, avoids weld eccentricity, greatly improves welding quality and efficiency, and reduces weld stress concentration. In addition, the present invention uses a new composite tenon connector. Compared with the small-sized bolt connectors of traditional lightweight composite bridge decks, the new composite tenon connector can also meet the UHPC thin layer's restriction on connector height, and has greater shear and pull-out strength and stiffness, and stronger deformation capacity in UHPC, ensuring that the steel bridge deck is tightly combined with the UHPC, and has better long-term performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0031] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0032] Figure 2 It is a schematic diagram of the front structure of the present invention.

[0033] Figure 3 It is a side structural schematic diagram of the present invention.

[0034] Figure 4 Schematic diagram of the shape of the tenon unit of the steel tenon.

[0035] Figure 5 Schematic diagram of the special-shaped hole shape of the diaphragm.

[0036] Figure 6 Schematic diagram of the laying relationship between transverse and longitudinal steel bars.

[0037] The symbols in the figure are:

[0038] 1-UHPC thin layer, 2-steel bridge deck, 3-steel tenon plate, 4-steel mesh, 5-plate rib, 6-diaphragm;

[0039] 31-tenon unit, 32-enlarged end, 33-contracted section, 34-special-shaped groove;

[0040] 41- transverse reinforcement, 42- longitudinal reinforcement;

[0041] 61-special-shaped hole, 62-upper extension, 63-slot. DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0043] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", "inside", "outside", "longitudinal", "lateral", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "fixed", "connected", "set" and the like should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] It should also be noted that although the order of steps is mentioned in the method description, in some cases, they may be performed in an order different from that shown here, and this should not be construed as a limitation on the order of the steps.

[0046] In a specific embodiment, the length direction of the plate rib 5 is defined as the longitudinal direction, and the direction perpendicular thereto is defined as the transverse direction.

[0047] The present invention provides a steel-UHPC composite bridge deck based on a composite tenon connector, adopts a new steel-concrete composite tenon as a shear connector, and a plate rib 5 as a longitudinal stiffening rib. As a bridge deck structure form for a long-span bridge, it can achieve the purposes of reducing welding operations, improving fatigue performance, reducing the number of connectors, and improving the long-term working performance of connectors, and provides a more advanced, more economical, and more durable bridge deck structure design and construction scheme for long-span bridges.

[0048] Specifically, Figure 1-3 The steel-UHPC composite bridge deck includes a steel bridge deck 2, a steel tenon plate 3, a steel mesh 4, a UHPC thin layer 1, a plate rib 5 and a diaphragm 6, forming a new type of orthotropic lightweight composite bridge deck, realizing the overall optimization and upgrading of the structure.

[0049] The steel tenon plate 3 is vertically fixed to the top surface of the steel bridge deck 2, and the top of the steel tenon plate 3 has a tenon-shaped unit 31 protruding upward. The steel tenon plate 3 is arranged longitudinally on the top surface of the steel bridge deck 2, and multiple tenon-shaped units 31 are arranged in parallel transversely. The tenon-shaped units 31 are evenly arranged longitudinally at equal intervals on the top of the steel tenon plate 3, with the top being an expanded end 32 and the bottom being a contracted section 33. There are special-shaped grooves 34 between adjacent tenon-shaped units 31. In some embodiments, the tenon-shaped units 31 can be formed by Figure 4 The shape in the middle transitions from the straight line segment on the left to the semicircular curve segment that is concave to the right on the left side of the contraction segment 33, then transitions upward to the semicircular curve segment that is convex to the left on the left side of the expansion end 32, and then transitions to the straight line segment at the top. The left and right parts of the tenon unit 31 are symmetrical in shape. Correspondingly, the special-shaped groove 34 transitions from the semicircular curve segment that is convex to the right on the right side of the expansion end 32, downward to the semicircular curve segment that is concave to the left on the right side of the contraction segment 33, and then transitions to the straight line segment at the bottom of the groove. The left and right parts of the special-shaped groove 34 are symmetrical in shape. The edges of the tenon unit 31 and the special-shaped groove 34 are smoothly transitioned in the longitudinal direction. Compared with the shear nails arranged in a welded array, there are fewer welding points and components. While the construction efficiency is improved, the long-term working performance can also be effectively improved.

[0050] The steel mesh 4 covers the top of the steel bridge deck 2, and the tenon-shaped units 31 are inserted into the grid of the steel mesh 4 and fixed to each other. The steel mesh 4 includes transverse steel bars 41 and longitudinal steel bars 42, which are tied to each other to form a steel skeleton.

[0051] The plate rib 5 is vertically fixed to the bottom of the steel bridge deck 2. The plate rib 5 is arranged longitudinally at the bottom of the steel bridge deck 2, and multiple plate ribs are arranged in parallel transversely, and the plate rib 5 corresponds to the position of the steel tenon plate 3 up and down. The plate rib 5 can be replaced by an open stiffening rib such as a bulb flat steel rib or a positive bulb flat steel rib.

[0052] The diaphragm 6 is arranged below the steel bridge deck 2. A vertical slot 63 is arranged at the top of the diaphragm 6. The plate rib 5 is inserted downward into the slot 63. The diaphragm 6 is arranged horizontally, and multiple diaphragms are arranged in parallel vertically. The bottom of the slot 63 has a special-shaped hole 61, and the top of the special-shaped hole 61 has an upper extension 62 on both sides of the slot 63. The special-shaped hole digging method reduces the stress level of the diaphragm 6 and its opening structure details, and improves its fatigue stress performance.

[0053] UHPC concrete is poured on the steel bridge deck 2, the steel tenon plate 3 and the steel mesh 4 to form a UHPC thin layer 1. The UHPC concrete filled in the special-shaped groove 34 of the steel tenon plate 3 forms a concrete tenon, and the tenon-shaped unit 31, the concrete tenon and the transverse steel bars 41 of the steel mesh 4 together form a combined tenon connector that resists the interface shear force. The combined tenon connector is PZ-shaped, and when the thickness of the UHPC thin layer is sufficient, it can be replaced by CL-shaped or MCL-shaped.

[0054] The combination of UHPC and orthotropic steel bridge deck to form an orthotropic lightweight composite bridge deck can increase the local stiffness of the bridge deck by more than 30 times. The stiffening effect of U-ribs on the bridge deck is weakened and can be replaced by plate ribs. Furthermore, the special-shaped holes in the diaphragm can reduce the stress level of the diaphragm and its opening structural details, and improve its fatigue stress performance. The new composite tenon connector can meet the UHPC thin layer height restriction requirements. Compared with small-sized studs, it has greater shear and pull-out strength and stiffness, stronger deformation capacity in UHPC, better long-term performance, and can greatly reduce the number of connectors and welding workload, ensuring that the steel bridge deck and UHPC are tightly combined, significantly improving the comprehensive stress performance of the bridge deck.

[0055] The construction method of the steel-UHPC composite bridge deck based on the composite tenon connector specifically includes the following steps:

[0056] Firstly, based on the design requirements of lightweight composite bridge decks, it is necessary to cut the steel bridge deck 2, steel tenon plates 3, steel meshes 4, plate ribs 5 and diaphragms 6. Among them, the steel bridge deck 2 and plate ribs 5 are directly rolled into shape according to the design dimensions, and the steel tenons 3 and diaphragms 6 need to be rolled into prototype steel plates respectively and then the prototype steel plates are cut into corresponding shapes.

[0057] S1: The bottom surface of the steel bridge deck 2 faces upwards, and the fixed plate rib 5 is welded at the bottom of the steel bridge deck 2, and a double-sided fillet weld method can be adopted.

[0058] S2: Align the slot 63 of the diaphragm 6 with the plate rib 5, so as to insert the plate rib 5 into the diaphragm 6, continuously weld the diaphragm 6, the plate rib 5 and the steel bridge deck 2, and weld the corners tightly.

[0059] S3: Place the top surface of the steel bridge deck 2 upward, lay out the steel tenon plate 3 according to the design requirements and grind the corresponding position of the top surface of the steel bridge deck 2 to make the surface of the steel plate flat and smooth, weld and fix the steel tenon plate 3 on the top of the steel bridge deck 2, and make the tenon unit 31 face upward.

[0060] S4: Lay the steel mesh 4 on top of the steel tenon plate 3 and insert the tenon-shaped unit 31 into the grid of the steel mesh 4.

[0061] Specifically, transverse steel bars 41 are placed on the notch of the special-shaped groove 34, and longitudinal steel bars 42 are laid on the top of the transverse steel bars 41 and tied to form a steel skeleton, keeping the spacing of the longitudinal steel bars 42 consistent with the spacing of the transverse steel bars 41. It is also possible to adopt a method of first tying to form a steel mesh and then laying it in the notch of the steel tenon plate 3.

[0062] S5: pouring UHPC concrete on the steel bridge deck 2, the steel tenon plate 3 and the steel mesh 4 to form a UHPC thin layer 1.

[0063] The grooves of the steel tenon plate 3 are filled with concrete tenons. The steel tenon plate 3, concrete tenons and transverse reinforcement 41 together form a new type of composite tenon connector that resists interface shear force, ensuring that the steel bridge deck 2 is tightly combined with the UHPC thin layer 1. The UHPC thin layer 1 is poured and cured to complete the manufacture of the steel-UHPC composite bridge deck using the composite tenon connector.

[0064] The technical solution of the present invention has the following technical advantages:

[0065] 1. The present invention utilizes the advantage of UHPC to greatly increase the stiffness of the bridge deck, optimizes the redundant longitudinal closed U-ribs into longitudinal open plate ribs, which are easier to manufacture than U-ribs and are welded to the steel bridge deck with double-sided fillet welds, which simplifies the welding process, avoids weld eccentricity, greatly improves welding quality and efficiency, and reduces weld stress concentration.

[0066] 2. The present invention improves the hole-digging form of the diaphragm, and can use computer numerical control (CNC) to accurately dig holes in the web of the diaphragm, so that it can be used as a template to help locate the plate ribs and achieve matching, thereby reducing the difficulty of quality control and manufacturing costs of the diaphragm.

[0067] 3. The present invention adopts a special-shaped method to dig holes, which reduces the stress level of the diaphragm and its opening structure details, improves the fatigue performance of the diaphragm through-holes, and comprehensively extends the fatigue life of the bridge deck structure.

[0068] 4. The present invention uses a new type of combined mortise and tenon connector. Compared with the small-sized bolt connectors of traditional lightweight composite bridge decks, the new type of combined mortise and tenon connector can also meet the restrictions on the height of the connectors in the UHPC thin layer, and has greater shear and pull-out strength and stiffness, and stronger deformation ability in UHPC, ensuring that the steel bridge deck and UHPC are tightly combined, and the long-term performance is better.

[0069] 5. The steel tenon plates of the present invention only need to be arranged correspondingly at the plate rib positions, and the number of connectors is greatly reduced. The steel tenons manufactured in advance are continuously welded on the top of the steel bridge deck and provide a laying base for the steel skeleton. After pouring the UHPC thin layer, a new type of combined tenon connector is formed. The construction process is simplified, the process is simple, and the construction quality and efficiency are significantly improved.

[0070] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. Steel-UHPC composite bridge deck based on composite tenon connectors, characterized by: The steel-UHPC composite bridge deck comprises a steel bridge deck (2), a steel tenon plate (3), a steel mesh (4) and a UHPC thin layer (1); The steel tenon plate (3) is vertically fixed to the top surface of the steel bridge deck (2), and the top of the steel tenon plate (3) has a tenon-shaped unit (31) protruding upward; The steel mesh (4) covers the top of the steel bridge deck (2), and the tenon-shaped units (31) are inserted into the grid of the steel mesh (4) and fixed to each other; UHPC concrete is poured on the steel bridge deck (2), the steel tenon plate (3) and the steel mesh (4) to form the UHPC thin layer (1).

2. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 1, characterized in that: The steel tenon plates (3) are arranged longitudinally on the top surface of the steel bridge deck (2), and a plurality of them are arranged transversely and in parallel.

3. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 2, characterized in that: The tenon-shaped units (31) are evenly arranged longitudinally on the top of the steel tenon plate (3), with the top being an expanded end (32) and the bottom being a contracted section (33); A special-shaped groove (34) is provided between adjacent tenon-shaped units (31).

4. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 3 is characterized in that: A plate rib (5) is provided below the steel bridge deck (2), and the plate rib (5) is vertically fixed to the bottom of the steel bridge deck (2).

5. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 4, characterized in that: The plate ribs (5) are arranged longitudinally at the bottom of the steel bridge deck (2), and a plurality of plate ribs (5) are arranged transversely and in parallel; The plate ribs (5) correspond to the steel tenon plates (3) in position up and down.

6. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 5, characterized in that: A transverse diaphragm (6) is arranged below the steel bridge deck (2), a vertical slot (63) is arranged on the top of the transverse diaphragm (6), and the plate rib (5) is inserted downward into the slot (63).

7. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 6, characterized in that: The transverse partitions (6) are arranged transversely, and a plurality of them are arranged longitudinally and in parallel.

8. The steel-UHPC composite bridge deck based on composite tenon connectors according to claim 7, characterized in that: The bottom of the slot (63) is provided with a special-shaped hole (61), and both sides of the slot (63) at the top of the special-shaped hole (61) are provided with upper extensions (62).

9. The construction method of the steel-UHPC composite bridge deck based on the composite tenon connector according to claim 8, characterized in that: The method comprises: The bottom surface of the steel bridge deck (2) faces upwards, and a fixed plate rib (5) is welded at the bottom of the steel bridge deck (2); Align the slot (63) of the diaphragm (6) with the plate rib (5), thereby inserting the plate rib (5) into the diaphragm (6), and continuously welding the diaphragm (6), the plate rib (5) and the steel bridge deck (2); Place the top surface of the steel bridge deck (2) facing upwards, and weld and fix the steel tenon plate (3) on the top of the steel bridge deck (2) so that the tenon-shaped unit (31) faces upwards; Laying the steel mesh (4) on top of the steel tenon plate (3) so that the tenon-shaped units (31) are inserted into the grid of the steel mesh (4); UHPC concrete is poured on the steel bridge deck (2), the steel tenon plate (3) and the steel mesh (4) to form the UHPC thin layer (1).

10. The construction method of a steel-UHPC composite bridge deck based on a composite tenon connector according to claim 9, characterized in that: The UHPC concrete filled in the special-shaped groove (34) of the steel tenon plate (3) forms a concrete tenon, and the tenon-shaped unit (31), the concrete tenon and the transverse steel bars (41) of the steel mesh (4) together form a combined tenon connector that resists interface shear force.

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