High filling soil self-stress butt strap structure and construction method

Abstract

The high filling soil self-stress butt strap structure comprises a left center plate, a right center plate and a longitudinal connecting seam, and is characterized in that a front center plate is composed of a reinforced concrete front center plate and a self-stress front center plate, and the self-stress front center plate is composed of longitudinal steel plate strips, transverse steel plate strips, longitudinal self-stress ribs, transverse self-stress ribs, upper and lower connecting ribs and high expansion concrete; and the longitudinal self-stress ribs and the transverse self-stress ribs are positioned above the longitudinal steel plate strips and are partially welded with the shear nails. The construction method comprises the following steps: a) welding the steel plate strips; b) binding reinforcing steel bars of the rear panel; c) binding a self-stress rib; d) pouring a rear panel; e) pouring a self-stress front panel; (f) pouring the front panel; g) hoisting the center plate; h) pouring a connecting seam; and i) cutting the pre-cut seam. According to the butt strap structure and the construction method, the firmness and durability of the center plates are improved, the crack resistance, bearing capacity and durability of the left center plate and the right center plate are improved, and the service life of the left center plate and the right center plate is prolonged.

Description

Technical Field

[0001] The present invention relates to a transition slab structure and a construction method, and more specifically, to a high-fill self-stress transition slab structure and a construction method. Background Art

[0002] In the construction of the transition section between a highway bridge and a high-fill subgrade, a transition slab is used to achieve the connection between the bridge and the subgrade. The traditional transition slab structure adopts an integral reinforced concrete slab or a prestressed concrete slab. Due to the significant post-construction settlement of the high-fill subgrade under the action of vehicle loads and its own gravity, while the settlement of the bridge structure is relatively small, obvious differential settlement is formed at the connection between the transition slab and the subgrade and the bridgehead. This differential settlement makes the transition slab present a stress characteristic of "rigid support at the bridge end and elastic support at the subgrade end", forming an approximately triangular void area under the transition slab on the bridge side, forcing the front part of the transition slab to be in a complex stress state of two-way bending.

[0003] Therefore, the existing bridgehead transition slabs have the following prominent problems: (1) Ordinary reinforced concrete transition slabs are prone to radial cracks under the two-way stress state. After 3 - 5 years of use of the transition slab, the crack width generally exceeds the specification limit of 0.3 mm, resulting in increased rainwater infiltration and aggravated subgrade erosion, forming a vicious cycle. (2) When prestressed concrete transition slabs are used in some projects, complex tensioning operations and grouting processes are required. On-site tensioning is easily restricted by construction conditions, and it is difficult to ensure the grouting density of the post-tensioned prestressed tendon ducts, resulting in quality hidden dangers. (3) Conventional transition slabs mostly adopt a single-layer reinforcement structure to control their own weight, and the transverse stiffness distribution is uneven. Finite element analysis shows that when the differential settlement of the transition slab reaches 20 mm, the bending moment in the transition slab increases by 2.8 times compared with the design value, leading to the structure entering the plastic deformation stage prematurely.

[0004] In view of the above problems, existing improvement schemes mostly optimize in aspects such as strengthening the reinforcement ratio or setting auxiliary support structures, but often lead to an increase in the structure thickness (the conventional slab thickness needs to be increased to more than 45 cm) or an increase in construction complexity. Especially in the aspect of self-stress regulation of the transition slab, a systematic structural solution has not been formed. Therefore, this article proposes a high-fill self-stress transition slab structure and a construction method to solve the problems existing in the existing transition slabs. Summary of the Invention

[0005] In order to overcome the above technical problems, the present invention provides a high-fill self-stress transition slab structure and a construction method.

[0006] The high-fill self-stressing slab structure of the present invention includes a left slab, a right slab, and a longitudinal joint. The left slab and the right slab are connected through the longitudinal joint. The left slab and the right slab are each composed of a front slab and a rear slab arranged successively from the front wall to the roadbed base layer. It is characterized in that: the front slab is composed of a reinforced concrete front slab and a self-stressing front slab, and the reinforced concrete front slab is located above the self-stressing front slab; the self-stressing front slab is composed of longitudinal steel strips, transverse steel strips, longitudinal self-stressing bars, transverse self-stressing bars, upper and lower connecting bars, and high-expansion concrete. The length directions of the longitudinal steel strips and the transverse steel strips are respectively consistent with the road driving direction and the road width direction, and adjacent longitudinal steel strips are connected by the spaced transverse steel strips. Vertical shear studs are evenly welded on the longitudinal steel strips and / or the transverse steel strips. The longitudinal self-stressing bars and the transverse self-stressing bars are located above the longitudinal steel strips and are partially welded to the shear studs; the upper and lower connecting bars are arranged vertically, and the lower ends of the upper and lower connecting bars are tied to the longitudinal self-stressing bars and / or the transverse self-stressing bars; the longitudinal steel strips, the transverse steel strips, the longitudinal self-stressing bars, the transverse self-stressing bars, the shear studs, and the lower parts of the upper and lower connecting bars are all cast in the high-expansion concrete, and the upper parts of the upper and lower connecting bars are cast in the reinforced concrete front slab; the rear ends of the longitudinal steel strips and the longitudinal self-stressing bars, and the rear transverse steel strips, the transverse self-stressing bars, and the shear studs are all cast in the rear slab; the reinforced concrete front slab and the rear slab are connected by pre-embedded front and rear slab connecting bars.

[0007] In the high-fill self-stressing slab structure of the present invention, the reinforced concrete front slab is composed of front slab longitudinal steel bars, front slab transverse steel bars, and first concrete. The front slab longitudinal steel bars and the front slab transverse steel bars are respectively consistent with the road driving direction and the road width direction. The front slab longitudinal steel bars and the front slab transverse steel bars are tied to each other. The front slab longitudinal steel bars, the front slab transverse steel bars, and the upper parts of the upper and lower connecting bars are all cast in the first concrete, and the front parts of the front and rear slab connecting bars are cast in the first concrete.

[0008] In the high-fill self-stressing slab structure of the present invention, the rear slab is composed of upper layer longitudinal bars, upper layer transverse bars, lower layer longitudinal bars, lower layer transverse bars, and second concrete. The upper layer transverse bars and the upper layer longitudinal bars are both located above the lower layer transverse bars and the lower layer longitudinal bars. The upper layer longitudinal bars are tied to the upper layer transverse bars, and the lower layer longitudinal bars are tied to the lower layer transverse bars; the upper layer longitudinal bars, the upper layer transverse bars, the lower layer longitudinal bars, and the lower layer transverse bars are all cast in the second concrete, and the rear parts of the front and rear slab connecting bars are cast in the second concrete.

[0009] In the high-fill self-stressing slab structure of the present invention, the longitudinal connection joint is composed of left and right slab connecting bars and slightly expanded concrete. The two ends of the left and right slab connecting bars are respectively embedded in the adjacent reinforced concrete front slab or rear slab. The exposed parts after the left and right slab connecting bars are embedded are poured in the slightly expanded concrete, and a pre-cut joint is cut in the upper part of the slightly expanded concrete.

[0010] In the high-fill self-stressing slab structure of the present invention, the lengths of the left slab and the right slab are both 8.0 m to 13.0 m, the total width after the left slab and the right slab are laid is 9.0 m to 12.0 m, the length of the front slab is 3.0 m to 4.0 m, and the length of the rear slab is 5.0 m to 9.0 m.

[0011] In the high-fill self-stressing slab structure of the present invention, both the longitudinal steel strips and the transverse steel strips adopt steel of type Q345B. The thickness of the longitudinal steel strips is 10 mm to 15 mm, the width is 80 mm to 150 mm, and the spacing between adjacent longitudinal steel strips is 200 mm to 300 mm; the thickness of the transverse steel strips is 10 mm to 15 mm, the width is 60 mm to 120 mm, and the spacing between adjacent transverse steel strips is 300 mm to 500 mm; The longitudinal self-stressing bars adopt steel bars of type HRB400 with a diameter of 12 mm to 18 mm, the transverse self-stressing bars adopt steel bars of type HRB335 with a diameter of 10 mm to 16 mm, the upper and lower connecting bars are in the shape of "]", the upper and lower connecting bars adopt steel bars of type HRB335 with a diameter of 10 mm to 16 mm, the spacing between adjacent shear studs is not greater than 150 mm, and the shear studs adopt studs with a diameter of 16 mm; The length of the longitudinal steel strips and the longitudinal self-stressing bars extending to the bottom of the rear slab is 60 cm to 120 cm.

[0012] In the high-fill self-stressing slab structure of the present invention, the longitudinal bars of the front slab adopt steel bars with a diameter of 16 mm to 18 mm and of type HRB335, the transverse bars of the front slab adopt steel bars with a diameter of 10 mm to 16 mm and of type HRB335. The distance between the longitudinal bars of the front slab and the top surface of the front slab is 5 cm to 6 cm, and the transverse bars of the front slab are located below the longitudinal bars of the front slab; Both the upper-layer longitudinal bars and the lower-layer longitudinal bars adopt steel bars with a diameter of 18 mm to 25 mm and of type HRB335, and both the upper-layer transverse bars and the lower-layer transverse bars adopt steel bars with a diameter of 14 mm to 16 mm and of type HRB335.

[0013] In the high-fill self-stressing slab structure of the present invention, the width of the longitudinal connection joint is 8 cm to 12 cm, and the left and right slab connecting bars adopt steel bars with a diameter of 22 mm to 25 mm and of type HRB335; the embedded length of the left and right slab connecting bars is not less than 30 times their diameter; The grades of the first concrete, the second concrete, the high-expansion concrete and the micro-expansion concrete are C35 to C40. The restricted expansion rate of the high-expansion concrete is 0.4% to 0.5%, and the restricted expansion rate of the micro-expansion concrete is 0.2% to 0.3%.

[0014] The construction method of the high-fill self-stressing slab structure of the present invention is characterized in that it is realized through the following steps: a). Welding steel strips; First, install longitudinal steel strips, and then weld transverse steel strips at equal intervals between adjacent longitudinal steel strips to form a grid skeleton of longitudinal steel strips and transverse steel strips, and then weld shear studs; b). Binding the steel bars of the rear slab; Bind the lower-layer longitudinal bars and lower-layer transverse bars at the lower part of the rear slab, bind the upper-layer longitudinal bars and upper-layer transverse bars at the upper part of the rear slab, and embed the front-back slab connecting bars and left-right half connecting bars; c). Binding self-stressing bars; Bind longitudinal self-stressing bars and transverse self-stressing bars, weld the longitudinal self-stressing bars and transverse self-stressing bars to the shear studs, and then bind the upper and lower connecting bars; d). Pouring the rear slab; Pour the second concrete and carry out curing for not less than 72 hours; e). Pouring the self-stressing front slab; Pour the high-expansion concrete and carry out wet curing for 7 days; f). Pouring the front slab; Bind the longitudinal bars and transverse bars of the front slab, pour the first concrete and cure for 7 days; Precast the left slab and the right slab according to steps a) to f); g). Hoisting the slab; Hoist the left slab and the right slab into place; h). Pouring the joint; Weld the left and right slab connecting bars aligned in the left and right slabs, then pour the micro-expansion concrete, and then carry out curing for not less than 5 days; i). Cutting the pre-cut joint; Cut a pre-cut joint with a depth of 1 / 4 to 1 / 3 of the thickness of the front slab, and pour hot asphalt after cleaning the cut pre-cut joint.

[0015] In the construction method of the high-fill self-stressing slab structure of the present invention, the width of the pre-cut joint cut in step i) is 8 mm to 12 mm, and a rotary joint cleaning machine is used to clean the joint wall of the pre-cut joint.

[0016] The beneficial effects of the present invention are as follows: For the high-fill self-stressing slab structure and construction method of the present invention, the left slab and the right slab are connected by a longitudinal joint. The left and right slabs are composed of a front slab and a rear slab arranged front and back. The front slab is further composed of a reinforced concrete front slab and a self-stressing front slab arranged up and down. The self-stressing front slab is composed of high-expansion concrete and longitudinal and transverse steel bars, longitudinal and transverse self-stressing steel bars, upper and lower connecting bars, and shear studs cast therein. The longitudinal and transverse steel bars are located at the bottom and form a grid skeleton, and the longitudinal and transverse self-stressing steel bars are located at the upper part and also form a grid skeleton. During the pouring and solidification of the high-expansion concrete, under the restraint of the longitudinal and transverse steel bars and the longitudinal and transverse self-stressing steel bars, compressive self-stress is generated inside the self-stressing front slab. The longitudinal compressive self-stress inside the self-stressing front slab can offset part of the tensile stress generated by the vehicle load above it, effectively improving the firmness and durability of the formed left and right slabs and avoiding concrete cracking during use. At the same time, the self-stressing front slab is connected to the reinforced concrete front slab through the upper and lower connecting bars, and the rear slab is connected to the front slab through the longitudinal steel bars, longitudinal self-stressing steel bars, and front and rear slab connecting bars extending into the rear slab, making the reinforced concrete front slab, self-stressing front slab, and rear slab form a firm overall structure, effectively improving the crack resistance, load-bearing capacity, durability, and service life of the left and right slabs.

[0017] It can be seen that the "longitudinal and transverse steel grid + shear studs + longitudinal and transverse self-stressing steel bars + high-expansion concrete" of the self-stressing front slab is a structure combining a three-dimensional grid structure of slabs, studs, and steel bars with new materials; the high strength and high stiffness of the grid structure composed of the longitudinal and transverse steel bars at the bottom provide stable base support, effectively dispersing the load and reducing local stress concentration, resulting in high load-bearing capacity of the formed left and right slabs; the grid structure forms a spatial force system, enhancing the bending resistance, shear resistance, and torsion resistance, and is suitable for heavy traffic with frequent loads.

[0018] By introducing compressive stress into the concrete through self-stressing steel bars, the grid arrangement formed by the longitudinal and transverse self-stressing steel bars forms a two-way self-stressing system, enhancing the isotropy of the structure, offsetting the tensile stress generated by external loads, and significantly improving the crack resistance; the self-stress makes the concrete fit more closely with the steel plates and steel bars, enhancing the interface bonding strength and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the high-fill self-stressing slab structure of the present invention; Figure 2 It is a transverse sectional view of the front slab part in the high-fill self-stressing slab structure of the present invention; Figure 3 It is a transverse sectional view of the rear slab part in the high-fill self-stressing slab structure of the present invention; Figure 4 It is a longitudinal sectional view of the left slab or the rear slab in the present invention.

[0020] In the figure: 1 front panel, 2 rear panel, 3 reinforced concrete front panel, 4 pre-stressed front panel, 5 first concrete, 6 second concrete, 7 high-expansion concrete, 8 front wall, 9 suspended area, 10 subgrade base course, 11 longitudinal steel strips, 12 transverse steel strips, 13 longitudinal pre-stressed steel bars, 14 transverse pre-stressed steel bars, 15 upper and lower connecting bars, 16 longitudinal steel bars of the front panel, 17 transverse steel bars of the front panel, 18 longitudinal connecting joint, 19 left and right panel connecting bars, 20 pre-cut joint, 21 slightly expanded concrete, 22 upper layer longitudinal bars, 23 upper layer transverse bars, 24 lower layer longitudinal bars, 25 lower layer transverse bars, 26 front and rear panel connecting bars, 27 shear studs, 28 corbel. Specific embodiments

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] As Figure 1 shown, a structural schematic diagram of the high-fill pre-stressed bridging slab structure of the present invention is given. It is composed of a left panel, a right panel and a longitudinal connecting joint 18. The left panel and the right panel are arranged at intervals along the width direction of the road, and the interval is the longitudinal connecting joint 18. The left panel and the right panel are connected through the longitudinal connecting joint 18. Both the left panel and the right panel are composed of a front panel 1 and a rear panel 2. The front panel 1 is arranged on the side close to the front wall 8, and the rear panel 2 is located on the side far from the front wall 8. The front panel 1 and the rear panel 2 are a prefabricated integral structure. The front panel 1 is composed of a reinforced concrete front panel 3 and a pre-stressed front panel 4. The reinforced concrete front panel 3 is located above the pre-stressed front panel 4. The front end of the pre-stressed front panel 4 is placed on the corbel 28, and the rear part is laid on the subgrade base course 10.

[0023] Due to the different settlement performances of the bridge foundation and the subgrade, during the long-term service of the road and the bridge, a suspended area 9 will appear in the subgrade outside the front wall 8. Due to the existence of the suspended area 9, the left and right panels lose the support of the subgrade base course 10 at the suspended area 9. If the strength and load-bearing capacity of the left and right panels are insufficient, it is easy to cause cracks in them, and even cause the left and right panels to break. The left and right panels composed of the reinforced concrete front panel 3, the pre-stressed front panel 4 and the rear panel 2 proposed in this article have good bending, shear and torsion resistance capabilities. Even if a suspended area 9 appears due to the uneven settlement of the bridge foundation and the subgrade foundation, it will not cause cracks or fractures in the left and right panels.

[0024] As Figure 2 and Figure 3 shown, the transverse cross-sectional views of the front panel part and the rear panel part in the high-fill pre-stressed bridging slab structure of the present invention are respectively given, that is Figure 2 is sectioned transversely along the road at the front panel 1 part, Figure 3It is sectioned transversely along the road at the position of the rear web plate 2; Figure 4 A longitudinal sectional view of the left web plate or the rear web plate in the present invention is given.

[0025] The shown self-stressing front web plate 4 is composed of longitudinal steel strips 11, transverse steel strips 12, longitudinal self-stressing bars 13, transverse self-stressing bars 14, upper and lower connecting bars 15, shear studs 27 and high-expansion concrete 7. The longitudinal steel strips 11 and the transverse steel strips 12 are arranged at the bottom. The length direction of the longitudinal steel strips 11 is consistent with the driving direction of the road, and the length direction of the transverse steel strips 12 is consistent with the width direction of the road. The longitudinal steel strips 11 are arranged at intervals, and adjacent two longitudinal steel strips 11 are connected by evenly spaced transverse steel strips 12. The transverse steel strips 12 and the longitudinal steel strips 11 are connected by welding. After the longitudinal steel strips 11 and the transverse steel strips 12 are welded, a steel plate skeleton with good tensile capacity is formed.

[0026] Vertical shear studs 27 are evenly welded on the longitudinal steel strips 11 and / or the transverse steel strips 12. The longitudinal self-stressing bars 13 and the transverse self-stressing bars 14 are located above the longitudinal steel strips 11. The length direction of the longitudinal self-stressing bars 13 is the same as the driving direction of the road, and the length direction of the transverse self-stressing bars 13 is the same as the width direction of the road. The longitudinal self-stressing bars 13 and the transverse self-stressing bars 14 are tied together to form a grid structure. Part of the longitudinal self-stressing bars 13 and part of the transverse self-stressing bars 14 are welded to the shear studs 27. The upper and lower connecting bars 15 are arranged vertically. The lower ends of the upper and lower connecting bars 15 are tied to the longitudinal self-stressing bars 13 and / or the transverse self-stressing bars 14. The lower parts of the upper and lower connecting bars 15 are cast in the self-stressing front web plate 4, and the upper parts of the upper and lower connecting bars 15 are cast in the reinforced concrete front web plate 3.

[0027] It can be seen that the steel plate grid skeleton composed of the longitudinal steel strips 11 and the transverse steel strips 12, the grid structure composed of the longitudinal self-stressing bars 13 and the transverse self-stressing bars 14, and the shear studs 27 and the upper and lower connecting bars 15 form a three-dimensional grid structure in the self-stressing front web plate 4. When the cast high-expansion concrete 7 solidifies, it will undergo micro-expansion. Under the constraint of the longitudinal steel strips 11, the transverse steel strips 12, the longitudinal self-stressing bars 13 and the transverse self-stressing bars 14, the formed self-stressing front web plate 4 will generate compressive self-stress.

[0028] We know that when there are vehicle loads above the left and right panels, they tend to bend downward, and the left and right panels that bend downward are in a state of "compression at the top and tension at the bottom", that is, "compression of the reinforced concrete front panel 3 and tension of the self-stressed front panel 4". We also know that concrete has great compressive strength, but insufficient tensile strength, while steel bars and steel plates have good tensile strength. In this way, the compressive stress of the self-stressed front panel 4 itself can offset the tensile stress caused by the vehicle load. At the same time, the longitudinal steel strips 11 and the longitudinal self-stressed tendons 13 have good tensile strength, thus ensuring that the front panel 1 formed by the self-stressed front panel 4 has good tensile strength and will not crack or break during long-term service.

[0029] The reinforced concrete front plate 3 shown is composed of the front plate longitudinal steel bars 16, the front plate transverse steel bars 17 and the first concrete 5. The front plate longitudinal steel bars 16 and the front plate transverse steel bars 17 are arranged at the upper center of the reinforced concrete front plate 3. The front plate longitudinal steel bars 16 and the front plate transverse steel bars 17 are tied to each other to form a grid structure. The front plate longitudinal steel bars 16 and the front plate transverse steel bars 17 are respectively consistent with the road driving direction and the road width direction. The upper and lower connecting bars 15 cast in the first concrete 5 and the high expansion concrete 7 respectively realize the firm connection between the self-stressed front plate 4 and the reinforced concrete front plate 3.

[0030] The rear plate 2 shown is composed of an upper longitudinal rib 22, an upper transverse rib 23, a lower longitudinal rib 24, a lower transverse rib 25 and a second concrete 6. The length directions of the upper longitudinal rib 22 and the lower longitudinal rib 24 are respectively consistent with the driving direction of the road, and the upper transverse rib 23 and the lower transverse rib 25 are respectively consistent with the width direction of the road. The upper longitudinal rib 22 and the upper transverse rib 23 are tied together to form a grid structure and are arranged on the upper part of the rear plate 2; the lower longitudinal rib 24 and the lower transverse rib 25 are tied together to form a grid structure and are arranged on the upper part of the rear plate 2. The upper part of the rear plate 2 shown is pre-embedded with front and rear plate connecting ribs 26, and the exposed parts of the front and rear plate connecting ribs 26 after pre-embedded are cast in the reinforced concrete front plate 3.

[0031] The rear ends of the longitudinal steel strips 11 and the longitudinal self-stressing tendons 13 extend into the rear plate 2, and the distance of the longitudinal steel strips 11 and the longitudinal self-stressing tendons 13 extends into the rear plate 2 by 60 cm to 120 cm; at the same time, a small amount of shear nails 27 and transverse steel strips 12 at the rear end are also cast into the rear plate 2. In this way, a strong rear plate 2 structure is formed after the second concrete 6 is cast.

[0032] It can be seen that due to the connection between the rear plate 2 and the reinforced concrete front plate 3 via the front and rear plate connecting ribs 26, the connection between the rear plate 2 and the self-stressed front plate 4 via the longitudinal steel plate strips 11 and the longitudinal self-stressed ribs 13, and the connection between the self-stressed front plate 4 and the reinforced concrete front plate 3 via the upper and lower connecting ribs 15, the reinforced concrete front plate 3, the self-stressed front plate 4 and the rear plate 2 form a solid whole. The formed overall structure has good tensile, shear and torsional properties, and will not produce cracks and fractures under the action of the upper vehicle load during service.

[0033] For the left and right panels formed by the front panel 1 and the rear panel 2, they are connected by a longitudinal connection seam 18, which is composed of micro-expansion concrete 21 and left and right panel connection ribs 19. The left and right panel connection ribs 19 are welded by two sections of steel bars. Before welding, the two sections of steel bars are respectively embedded in the adjacent two rear panels 2 or embedded in the adjacent two reinforced concrete front panels 3, and then poured with micro-expansion concrete 21 after welding. A pre-cut seam 20 is cut on the upper part of the micro-expansion concrete 21. Under the micro-expansion effect of the poured micro-expansion concrete 21, the left and right panels on both sides are compressed, realizing the rigid connection between the left and right panels, making them bear force as a whole, and ensuring that they have good firmness.

[0034] The length of the left and right panels is 8.0m~13.0m, the total width of the left and right panels after laying is 9.0m~12.0m, the length of the front panel 1 is 3.0m~4.0m, and the length of the rear panel 2 is 5.0m~9.0m. The longitudinal steel strips 11 and the transverse steel strips 12 are both made of Q345B steel, the thickness of the longitudinal steel strips 11 is 10mm~15mm, the width is 80mm~150mm, and the spacing between adjacent longitudinal steel strips 11 is 200mm~300mm; the thickness of the transverse steel strips 12 is 10mm~15mm, the width is 60mm~120mm, and the spacing between adjacent transverse steel strips 12 is 300mm~500mm.

[0035] The longitudinal self-stressing tendons 13 are made of steel bars with model HRB400 and diameter of 12mm~18mm, the transverse self-stressing tendons 14 are made of steel bars with model HRB335 and diameter of 10mm~16mm, the upper and lower connecting tendons are in "]" shape, the upper and lower connecting tendons 15 are made of steel bars with model HRB335 and diameter of 10mm~16mm, the spacing between adjacent shear studs 27 is not greater than 150mm, and the shear studs are studs with a diameter of 16mm.

[0036] The longitudinal steel bars 16 of the front gusset plate are made of steel bars with a diameter of 16 mm to 18 mm and a model of HRB335. The transverse steel bars 17 of the front gusset plate are made of steel bars with a diameter of 10 mm to 16 mm and a model of HRB335. The distance between the longitudinal steel bars of the front gusset plate and the top surface of the front gusset plate 1 is 5 cm to 6 cm. The transverse steel bars of the front gusset plate are located below the longitudinal steel bars of the front gusset plate. Both the upper longitudinal bars 22 and the lower longitudinal bars 24 are made of steel bars with a diameter of 18 mm to 25 mm and a model of HRB335. Both the upper transverse bars 23 and the lower transverse bars 25 are made of steel bars with a diameter of 14 mm to 16 mm and a model of HRB335.

[0037] The width of the longitudinal connection seam 18 is 8 cm to 12 cm. The left and right plate connecting bars 19 are made of steel bars with a diameter of 22 mm to 25 mm and a model of HRB335. The embedded length of the left and right plate connecting bars 19 is not less than 30 times their diameter. The grades of the first concrete 5, the second concrete 6, the high-expansion concrete 7, and the slightly-expansion concrete 21 are C35 to C40. The restricted expansion rate of the high-expansion concrete 7 is 0.4% to 0.5%. The restricted expansion rate of the slightly-expansion concrete 21 is 0.2% to 0.3%.

[0038] The construction method of the high-fill self-stressing slab structure of the present invention is realized through the following steps: a). Welding steel strips; first install the longitudinal steel strips 11, then weld the transverse steel strips 12 at equal intervals between adjacent longitudinal steel strips to form a grid skeleton of the longitudinal and transverse steel strips, and then weld the shear studs 27; b). Binding the steel bars of the rear gusset plate; bind the lower longitudinal bars 24 and the lower transverse bars 25 at the lower part of the rear gusset plate, bind the upper longitudinal bars 22 and the upper transverse bars 23 at the upper part of the rear gusset plate, and embed the front and rear plate connecting bars 26 and the left and right half connecting bars 19; c). Binding the self-stressing bars; bind the longitudinal self-stressing bars 13 and the transverse self-stressing bars 14, weld the longitudinal self-stressing bars and the transverse self-stressing bars to the shear studs, and then bind the upper and lower connecting bars 15; d). Pouring the rear gusset plate; pour the second concrete 6 and carry out curing for not less than 72 hours; e). Pouring the self-stressing front gusset plate; pour the high-expansion concrete 7 and carry out water curing for 7 days; f). Pouring the front gusset plate; bind the longitudinal steel bars 16 and the transverse steel bars 17 of the front gusset plate, pour the first concrete 5 and cure for 7 days; Precast the left gusset plate and the right gusset plate according to steps a) to f); g). Hoisting the gusset plates; hoist the left gusset plate and the right gusset plate into place; h). Pour the connection joint; weld the left and right plate connecting bars 19 aligned in the left and right side plates, then pour the slightly expanding concrete 21, and then carry out curing for not less than 5 days; i). Cut the pre-cut joint; cut the pre-cut joint 20 with a depth of 1 / 4 to 1 / 3 of the thickness of the front side plate 1, and pour hot asphalt after cleaning the cut pre-cut joint.

[0039] Among them, the width of the pre-cut joint 20 cut in step i) is 8 mm to 12 mm, and a rotary joint cleaning machine is used to clean the joint wall of the monthly cut joint 20.

[0040] It can be seen that the high-fill self-stress slab structure and construction method of the present invention have the following performances: (1) Excellent crack resistance. The synergistic effect of the self-stress steel bars (longitudinal self-stress bars 13 and transverse self-stress bars 14) and the high-expansion concrete forms a compressive stress state, which can almost eliminate the risk of concrete cracking in the service stage.

[0041] (2) High load-bearing efficiency. The steel plate grid (formed by the longitudinal steel strips 11 and the transverse steel strips 12) and the concrete are combined to bear the load, giving full play to the tensile strength of the steel and the compressive strength of the concrete, and realizing a lightweight and high-strength structure.

[0042] (3) Durability and long service life. Crack control can reduce environmental erosion (such as the intrusion of chloride ions and water vapor), extend the service life of the structure, and reduce maintenance costs.

Claims

1. A self-stressing slab structure for high fill, comprising a left slab, a right slab and a longitudinal joint (18), the left slab and the right slab being connected through the longitudinal joint, and both the left slab and the right slab being composed of a front slab (1) and a rear slab (2) sequentially arranged from a front wall (8) to a subgrade base layer (10); characterized in that: The front apron plate (1) is composed of a reinforced concrete front apron plate (3) and a self-stressing front apron plate (4), and the reinforced concrete front apron plate is located above the self-stressing front apron plate; the self-stressing front apron plate is composed of longitudinal steel strips (11), transverse steel strips (12), longitudinal self-stressing steel bars (13), transverse self-stressing steel bars (14), upper and lower connecting bars (15) and high-expansion concrete (7). The length directions of the longitudinal steel strips and the transverse steel strips are respectively consistent with the road driving direction and the road width direction, and adjacent longitudinal steel strips are connected by the intermittently arranged transverse steel strips; Vertically arranged shear studs (27) are evenly welded on the longitudinal steel strips and / or the transverse steel strips. The longitudinal self-stressing steel bars and the transverse self-stressing steel bars are located above the longitudinal steel strips and are partially welded to the shear studs; the upper and lower connecting bars are arranged vertically, and the lower ends of the upper and lower connecting bars are tied to the longitudinal self-stressing steel bars and / or the transverse self-stressing steel bars; the lower parts of the longitudinal steel strips, the transverse steel strips, the longitudinal self-stressing steel bars, the transverse self-stressing steel bars, the shear studs and the upper and lower connecting bars are all poured in the high-expansion concrete, and the upper parts of the upper and lower connecting bars are poured in the reinforced concrete front apron plate (3); the rear ends of the longitudinal steel strips (11) and the longitudinal self-stressing steel bars (13) and the rear transverse steel strips, the transverse self-stressing steel bars (14) and the shear studs are all poured in the rear apron plate (2); the reinforced concrete front apron plate (3) and the rear apron plate (2) are connected by the pre-embedded front and rear plate connecting bars (26).

2. The high-fill self-stressing slab structure according to claim 1, wherein: The reinforced concrete front apron plate (3) is composed of front apron plate longitudinal steel bars (16), front apron plate transverse steel bars (17) and first concrete (5). The front apron plate longitudinal steel bars and the front apron plate transverse steel bars are respectively consistent with the road driving direction and the road width direction, and the front apron plate longitudinal steel bars and the front apron plate transverse steel bars are tied to each other. The upper parts of the front apron plate longitudinal steel bars, the front apron plate transverse steel bars and the upper and lower connecting bars (15) are all poured in the first concrete, and the front part of the front and rear plate connecting bars (26) is poured in the first concrete.

3. The high-fill self-stressing slab structure according to claim 2, characterized in that: The rear apron plate (2) is composed of upper layer longitudinal steel bars (22), upper layer transverse steel bars (23), lower layer longitudinal steel bars (24), lower layer transverse steel bars (25) and second concrete (6). The upper layer transverse steel bars and the upper layer longitudinal steel bars are both located above the lower layer transverse steel bars and the lower layer longitudinal steel bars. The upper layer longitudinal steel bars are tied and connected with the upper layer transverse steel bars, and the lower layer longitudinal steel bars are tied and connected with the lower layer transverse steel bars; the upper layer longitudinal steel bars, the upper layer transverse steel bars, the lower layer longitudinal steel bars and the lower layer transverse steel bars are all poured in the second concrete, and the rear part of the front and rear plate connecting bars (26) is poured in the second concrete.

4. The high-fill self-stressing slab structure according to claim 3, wherein: The longitudinal connection joint (18) is composed of left and right plate connecting bars (19) and slightly expanded concrete (21). The two ends of the left and right plate connecting bars are respectively pre-embedded in the adjacent reinforced concrete front apron plates (3) or rear apron plates (2). The exposed parts after the left and right plate connecting bars are pre-embedded are poured in the slightly expanded concrete, and a pre-cut joint (20) is cut on the upper part of the slightly expanded concrete.

5. The high-fill self-stressing slab structure according to claim 1 or 2, characterized in that: The lengths of the left and right side plates are both 8.0 m to 13.0 m, and the total width after the left and right side plates are laid is 9.0 m to 12.0 m. The length of the front plate (1) is 3.0 m to 4.0 m, and the length of the rear plate (2) is 5.0 m to 9.0 m.

6. The high-fill self-stressing slab structure according to claim 1 or 2, characterized in that: Both the longitudinal steel strips (11) and the transverse steel strips (12) are made of steel of type Q345B. The thickness of the longitudinal steel strips is 10 mm to 15 mm, and the width is 80 mm to 150 mm. The spacing between adjacent longitudinal steel strips is 200 mm to 300 mm; the thickness of the transverse steel strips is 10 mm to 15 mm, and the width is 60 mm to 120 mm. The spacing between adjacent transverse steel strips is 300 mm to 500 mm; The longitudinal self-stressing tendons (13) are made of steel bars of type HRB400 with a diameter of 12 mm to 18 mm, and the transverse self-stressing tendons (14) are made of steel bars of type HRB335 with a diameter of 10 mm to 16 mm. The upper and lower connecting bars are in the shape of "]", and the upper and lower connecting bars (15) are made of steel bars of type HRB335 with a diameter of 10 mm to 16 mm. The spacing between adjacent shear studs (27) is not greater than 150 mm, and the shear studs are stud bolts with a diameter of 16 mm; The lengths of the longitudinal steel strips (11) and the longitudinal self-stressing tendons (13) extending to the bottom of the rear plate (2) are 60 cm to 120 cm.

7. The high-fill self-stressing slab structure according to claim 3, characterized in that: The longitudinal bars (16) of the front plate are made of steel bars with a diameter of 16 mm to 18 mm and type HRB335, and the transverse bars (17) of the front plate are made of steel bars with a diameter of 10 mm to 16 mm and type HRB335. The distance between the longitudinal bars of the front plate and the top surface of the front plate (1) is 5 cm to 6 cm, and the transverse bars of the front plate are located below the longitudinal bars of the front plate; Both the upper-layer longitudinal bars (22) and the lower-layer longitudinal bars (24) are made of steel bars with a diameter of 18 mm to 25 mm and type HRB335, and both the upper-layer transverse bars (23) and the lower-layer transverse bars (25) are made of steel bars with a diameter of 14 mm to 16 mm and type HRB335.

8. The high-fill self-stressing slab structure according to claim 4, characterized in that: The width of the longitudinal joint (18) is 8 cm to 12 cm, and the left and right plate connecting bars (19) are made of steel bars with a diameter of 22 mm to 25 mm and type HRB335; the embedded length of the left and right plate connecting bars is not less than 30 times their diameter; The grades of the first concrete (5), the second concrete (6), the high-expansion concrete (7) and the slightly-expansion concrete (21) are C35 to C40. The restricted expansion rate of the high-expansion concrete is 0.4% to 0.5%, and the restricted expansion rate of the slightly-expansion concrete is 0.2% to 0.3%.

9. A construction method for the high-fill self-stressing slab structure according to claim 4, characterized in that, It is realized through the following steps: a). Welding the steel strips; First, install the longitudinal steel strips (11), and then weld the transverse steel strips (12) at equal intervals between adjacent longitudinal steel strips to form a grid skeleton of the longitudinal and transverse steel strips, and then weld the shear studs (27); b). Tie the web reinforcement; Tie the lower longitudinal bars (24) and lower transverse bars (25) at the lower part of the web, tie the upper longitudinal bars (22) and upper transverse bars (23) at the upper part of the web, and embed the front and rear plate connecting bars (26) and left and right half connecting bars (19); c). Tie the self-stressing bars; Tie the longitudinal self-stressing bars (13) and transverse self-stressing bars (14), weld the longitudinal self-stressing bars and transverse self-stressing bars to the shear studs, and then tie the upper and lower connecting bars (15); d). Pour the web; Pour the second concrete (6) and cure for no less than 72 hours; e). Pour the self-stressing front plate; Pour the high-expansion concrete (7) and cure with water for 7 days; f). Pour the front plate; Tie the longitudinal bars (16) and transverse bars (17) of the front plate, pour the first concrete (5) and cure for 7 days; Precast the left and right plates according to steps a) to f); g). Lift the plates; Lift the left and right plates into position; h). Pour the joint; Weld the aligned left and right plate connecting bars (19) in the left and right plates, then pour the slightly expanding concrete (21), and then cure for no less than 5 days; i). Cut the pre-cut joint; Cut a pre-cut joint (20) with a depth of 1 / 4 to 1 / 3 of the thickness of the front plate (1), clean the cut pre-cut joint and pour hot asphalt into it.

10. The construction method of the high-fill self-stressing slab structure according to claim 9, characterized in that: The width of the pre-cut joint (20) cut in step i) is 8 mm to 12 mm, and a rotary joint cleaner is used to clean the wall of the pre-cut joint (20).

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