A road structure under a bridge with limited clearance
By setting up anchor static press piles and micro-expanded concrete in the original soil under the bridge, a stable roadbed structure is formed, which solves the problem of impact on pile foundation when a new road passes under the existing bridge, and achieves stable roadbed support and construction safety.
Patent Information
- Application Number
- CN202422001258.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-19
- Publication Date
- 2025-04-08
- Estimated Expiration
- 2034-08-19
AI Technical Summary
When a new road is built to penetrate existing bridges, it is difficult for the existing technology to avoid the impact on the pile foundation of the existing bridge. Especially when the clearance is limited, there are stability and vibration problems between conventional roadbeds and pile foundation roadbeds.
A under-bridge road structure with limited clearance is adopted, including anchor static press piles, gravel cushion layer, pile bearing plate, permeable layer, sealing layer and surface layer. Through the contact between anchor static press piles and the original soil under the bridge and the sealing of micro-expanded concrete, the firm connection between anchor static press piles and pile bearing plates is achieved, forming a stable roadbed structure.
This structure achieves stable support for the pile bearing plate through the friction force of the anchor static press pile and the pressure of the slightly expanded concrete, avoiding adverse effects on the pile foundation of the existing bridge, and no vibration occurs during the construction process, ensuring the stability of the newly built roadbed and the safety of the existing bridge.
Smart Images
Figure CN222730261U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a road structure, and more specifically, to an under-bridge road structure with limited clearance. Background Art
[0002] With the development of urbanization in my country, the supporting road traffic network has also expanded and developed synchronously, and the situation of new roads passing under existing railways or existing highways has emerged. When a new road passes under an existing road (railway or highway), it is necessary not to affect the pile foundation of the existing road or to control the impact within the permitted range. Therefore, the existing conventional roadbed and pile foundation roadbed are no longer applicable. This is because, due to the limited clearance height under the existing road, if a conventional roadbed is used, it is necessary to dig deeper into the original soil under the bridge. The deeper digging of the original soil under the bridge will inevitably affect the pile foundation of the existing road, which will adversely affect the stability of the pile foundation.
[0003] If a pile foundation roadbed is used, a larger piling machine is required for piling operations, and the existing road clearance with limited height is difficult to accommodate piling operations. Even if it can accommodate piling operations, it will inevitably generate large vibrations during the piling process, which will also have an adverse effect on the bearing capacity and stability of the existing road pile foundation. It can be seen that there is an urgent need to propose a new type of roadbed structure to meet the requirement of not affecting its stability when passing under an existing road; therefore, the utility model proposes a road structure suitable for underpasses with limited clearance, which will basically not have an adverse effect on its stability when passing under a bridge of an existing road. Summary of the invention
[0004] In order to overcome the disadvantages of the above technical problems, the utility model provides a road structure under the bridge with limited clearance.
[0005] The utility model provides a road structure under a bridge with limited clearance, comprising anchor static pressure piles, a crushed stone cushion layer, a pile support plate, a permeable layer, a sealing layer and a surface layer arranged in sequence from bottom to top in the original soil under the bridge; the utility model is characterized in that: vertical pressing holes for pressing the anchor static pressure piles are evenly opened on the pile support plate, the anchor static pressure piles are vertically inserted into the original soil under the bridge below the crushed stone cushion layer, the upper ends of the anchor static pressure piles pass through the crushed stone cushion layer and extend into the pressing holes; the pressing holes are provided with cross-shaped sealing steel bars pre-buried in the pile support plate, micro-expansion concrete is poured in the pressing holes, and anchor bolts for assisting in pressing the anchor static pressure piles are pre-buried in the pile support plate outside the pressing holes.
[0006] The utility model provides a road structure under a bridge with limited clearance, wherein the blocking steel bars are composed of four single steel bars uniformly pre-buried in the pile support plate, the pre-buried length of the single steel bar in the pile support plate is not less than 30 times of its diameter, and the four single steel bars are bent upward when the anchor static pressure pile is pressed into the pressure hole, and when the anchor static pressure pile is pressed into place and before the micro-expansion concrete blocks the pressure hole, the two opposite single steel bars are folded into a horizontal state and welded together.
[0007] In the utility model, the underbridge road structure with limited clearance is characterized in that the anchor bolts are exposed from the upper surface of the pile support plate, and the portion of the anchor bolts exposed from the pile support plate is used to fix the reaction frame and the jack for pressing the anchor static pressure piles; when the anchor static pressure piles are pressed into place, the portion of the anchor bolts exposed from the pile support plate is cut off.
[0008] The utility model provides a road structure under a bridge with limited clearance, wherein the cross sections of the press-in hole and the anchor static pressure pile are both square, and the anchor static pressure pile is pressed into the press-in hole cylinder axis; the side length of the press-in hole is 8 cm to 12 cm longer than the side length of the anchor static pressure pile.
[0009] The utility model provides a road structure under a bridge with limited clearance, wherein the pile support plate is composed of ordinary concrete and transverse ribs and longitudinal ribs cast in the ordinary concrete, the thickness of the pile support plate is 32 cm to 35 cm, and the grade of the ordinary concrete is 35 MPa to 40 MPa.
[0010] In the road structure under a bridge with limited clearance of the utility model, the distance between two adjacent pressed holes in the longitudinal direction and the transverse direction on the pile support plate is 2.5m-5.0m.
[0011] The utility model provides a road structure under a bridge with limited clearance, wherein the side length of the cross section of the anchor static pressure pile is 18 cm to 30 cm, the length of the anchor static pressure pile is 3.0 m to 6.0 m, the length of the anchor static pressure pile extending into the pile support plate is 5 cm to 7 cm, and the grade of the micro-expansive concrete is 40 MPa to 45 MPa.
[0012] The beneficial effects of the utility model are as follows: the road structure under the bridge with limited clearance of the utility model comprises anchor static pressure piles, crushed stone cushion layer, pile support plate, permeable layer, sealing layer and surface layer arranged in the original soil under the bridge from bottom to top, the pile support plate is evenly provided with pressing holes for pressing the anchor static pressure piles, sealing steel bars are arranged in the pressing holes, and anchor bolts are arranged on the periphery of the pressing holes. In this way, after shallow excavation of the original soil under the bridge, the crushed stone cushion layer is laid, and then the pile support plate is cast on the crushed stone cushion layer. After the cast pile support plate is cured, the anchor static pressure piles are pressed into the crushed stone cushion layer below and the original soil under the bridge through the reaction frame and jack fixed on the anchor bolts. After all the anchor static pressure piles are pressed in, the sealing steel bars are welded, and then micro-expansion concrete is cast in the pressing holes. Finally, the permeable layer, sealing layer and surface layer are laid in sequence above the pile support plate. It can be seen that The road structure under the bridge with limited clearance of the utility model relies on the friction force generated by the large contact area between the anchor static pressure pile and the original soil under the bridge to achieve support for the pile support plate, relies on the large pressure between the micro-expansive concrete in the pressed hole on the pile support plate and the inner wall of the pressed hole, and the limiting position of the micro-expansive concrete by the sealing steel bar to achieve a firm connection between the anchor static pressure pile and the pile support plate, thereby achieving a stable support of the pile support plate by the anchor static pressure pile, and finally forming a stable roadbed structure when the new road passes under the existing bridge. Compared with the existing conventional roadbed and pile foundation roadbed, the original soil under the bridge will not be deeply excavated, and the pressing of the anchor static pressure pile will not generate vibration, and will not affect the stability of the pile foundation of the existing bridge. While ensuring that the stability of the roadbed of the new road meets the requirements, it will not endanger the existing bridge. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a front view of the road structure under the bridge with limited clearance of the utility model;
[0014] Figure 2 A top view of a road structure under a bridge with limited clearance according to the utility model;
[0015] Figure 3 for Figure 1 A partial enlarged view of the middle A area;
[0016] Figure 4 This is a structural diagram of the anchor static pressure pile in the utility model when it is pressed into the pressure hole;
[0017] Figure 5 for Figure 2 A partial enlarged view of area B in the middle.
[0018] In the figure: 1 pile foundation, 2 pier, 3 original soil under the bridge, 4 crushed stone cushion, 5 pile deck, 6 permeable layer, 7 sealing layer, 8 surface layer, 9 anchor static pressure piles, 10 pressed holes, 11 sealing steel bars, 12 slightly expansive concrete, 13 anchor bolts, 14 ordinary concrete, 15 transverse bars, 16 longitudinal bars, 17 single steel bars. DETAILED DESCRIPTION
[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments.
[0020] like Figure 1 and Figure 2 As shown, a front view and a top view of the road structure under the bridge with limited clearance of the utility model are respectively given. Figure 3 Given Figure 1 A partial enlarged view of area A in the middle. Figure 4 This is a structural diagram of the anchor static pressure pile in the utility model when it is pressed into the pressure hole. Figure 5 Given Figure 2 A partial enlarged view of the area B in the middle shows that the road structure under the bridge with limited clearance is composed of anchor static pressure piles 9, a crushed stone cushion layer 4, a pile support plate 5, a permeable layer 6, a sealing layer 7 and a surface layer 8 arranged in the original soil 3 under the bridge from bottom to top. The crushed stone cushion layer 4 is arranged above the original soil 3 under the bridge after shallow excavation, and the pile support plate 5 is laid above the crushed stone cushion layer 4. The pile support plate 5 is formed by on-site casting. In order to ensure that the pile support plate 5 has good stability, the pile support plate 5 is composed of ordinary concrete 14 and transverse reinforcement 15 and longitudinal reinforcement 16 cast in the ordinary concrete 14. The transverse reinforcement 15 is arranged at equal intervals in the longitudinal direction of the road, and the longitudinal reinforcement 16 is arranged at equal intervals in the transverse direction of the road.
[0021] The pile support plate 5 is provided with press-in holes 10 at equal intervals in the transverse and longitudinal directions, and the press-in holes 10 are reserved and formed when the pile support plate 5 is cast. A cross-shaped plugging steel bar 11 is provided in the middle and upper part of the press-in hole 10, and the plugging steel bar 11 is anchored in the pile support plate 5; the plugging steel bar 11 is composed of four evenly distributed single steel bars 17, and the angle between two adjacent single steel bars 17 is 90°. When the anchor static pressure pile 9 is pressed into the original soil 3 under the bridge below through the press-in hole 10, the single steel bar 17 needs to be folded upward first to avoid the single steel bar 17 affecting the pressing of the anchor static pressure pile 9.
[0022] After the anchor static pressure pile 9 is pressed in and before the micro-expansion concrete 12 is poured, the bent single steel bar 17 is flattened and welded together to form a cross-shaped plugging steel bar 11. Anchor bolts 13 are fixed to the outside of the four corners of the pressing hole 10, and the anchor bolts 13 are anchored in the pile support plate 5. Before the anchor static pressure pile 9 is pressed in, the anchor bolts 13 also have a portion exposed on the upper surface of the pile support plate 5. The portion of the anchor bolt 13 exposed on the upper surface of the pile support plate 5 is used to fix the reaction frame and the jack, so that the reaction frame and the jack can press the anchor static pressure pile 9 in; later, before laying the permeable layer 6, it is necessary to shear off the portion of the anchor bolt 13 exposed on the upper surface of the pile support plate 5.
[0023] The upper end of the anchor static pile 9 shown in the figure passes through the gravel cushion layer 4 and extends into the pressure hole 10, that is, the upper end of the anchor static pile 9 extends into the pile support plate 5 for a certain length. After the anchor static pile 9 is pressed in and a single steel bar 17 is welded to form a plugging steel bar 11, a micro-expansion concrete 12 is poured into the pressure hole 10. After the micro-expansion concrete 12 solidifies in the pressure hole 10, the anchor static pile 9 is firmly fixed in the pressure hole 10 by utilizing its micro-expansion effect and the plugging effect of the plugging steel bar 11 on the micro-expansion concrete 12.
[0024] It can be seen that the road structure under the bridge with limited clearance of the utility model is to shallowly dig the original soil 3 under the bridge of the existing bridge, lay the crushed stone cushion layer 4, and then cast the pile support plate 5. After the pile support plate 5 is cured, the anchor static pile 9 is pressed in, and then welded to form the blocking steel bar 11 and cast the micro-expansion concrete 12. Finally, the permeable layer 6, the sealing layer 7 and the surface layer 8 are laid, and a sufficient number of anchor static piles 9 are used to have a large contact area with the original soil 3 under the bridge to form a sufficient support force of the original soil 3 under the bridge to the anchor static pile 9, thereby achieving a stable support for the pile support plate 5, and finally forming a stable new road under the existing bridge. During the entire construction process, there is no need to deeply dig the original soil 3 under the bridge, and no vibration machinery will be used, so it will not have an adverse effect on the stability and bearing capacity of the pile foundation 1 of the existing bridge, and will not endanger the safety of the existing bridge.
[0025] The cross sections of the press-in hole 10 and the anchor static pressure pile 9 are both in the positive direction, and the anchor static pressure pile 9 should be pressed into the cylinder axis of the press-in hole 10. The side length of the square cross section of the anchor static pressure pile 9 is 18cm~30cm. In order to ensure that the bending of the single steel bar 17 will not affect the pressing of the anchor static pressure pile 9, and the micro-expansion concrete 12 poured in the press-in hole 10 can achieve the surrounding of the top of the anchor static pressure pile 9, the side length of the inner diameter of the press-in hole 10 is 8cm~12cm longer than the side length of the cross section of the anchor static pressure pile 9. In this way, a gap of 4cm~6cm will be left between the outer wall of the anchor static pressure pile 9 and the inside of the press-in hole 10.
[0026] As specific requirements, the embedded length of a single steel bar 17 in the pile support plate is not less than 30 times its diameter; the distance between two adjacent pressure holes 10 in the longitudinal and transverse directions on the pile support plate 5 is 2.5m~5.0m; the length of the anchor static pressure pile 9 is 3.0m~6.0m, the length of the anchor static pressure pile 9 extending into the pile support plate 5 is 5cm~7cm, and the grade of the micro-expansive concrete 12 is 40MPa~45MPa. The surface layer adopts an asphalt concrete layer, and the permeable layer 6 adopts a modified emulsified asphalt layer.
Claims
1. A road structure under a bridge with limited clearance, comprising anchor static pressure piles (9), a crushed stone cushion layer (4), a pile support plate (5), a permeable layer (6), a sealing layer (7) and a surface layer (8) arranged in order from bottom to top in the original soil (3) under the bridge; characterized in that: Vertical insertion holes (10) for inserting anchor static pressure piles (9) are evenly formed on the pile support plate. The anchor static pressure piles are vertically inserted into the original soil under the bridge below the gravel cushion layer. The upper ends of the anchor static pressure piles pass through the gravel cushion layer and extend into the insertion holes. The insertion holes are provided with cross-shaped plugging steel bars (11) pre-buried in the pile support plate. Micro-expansive concrete (12) is poured in the insertion holes. Anchor bolts (13) for assisting the insertion of the anchor static pressure piles are pre-buried in the pile support plate outside the insertion holes.
2. The road structure under a bridge with limited clearance according to claim 1, characterized in that: The plugging steel bar (11) is composed of four single steel bars (17) uniformly pre-buried in the pile support plate (5), the pre-buried length of the single steel bar in the pile support plate being not less than 30 times its diameter, and the four single steel bars are bent upward when the anchor static pressure pile (9) is pressed into the pressure hole, and when the anchor static pressure pile is pressed into place and before the micro-expansion concrete (12) is used to plug the pressure hole, the two opposing single steel bars are folded into a horizontal state and welded together.
3. The road structure under a bridge with limited clearance according to claim 1 or 2, characterized in that: The anchor bolts (13) are exposed on the upper surface of the pile support plate (5), and the portion of the anchor bolts exposed on the pile support plate is used to fix the reaction frame and the jack for pressing the anchor static pressure pile (9) into place; when the anchor static pressure pile is pressed into place, the portion of the anchor bolts exposed on the pile support plate is cut off.
4. The road structure under a bridge with limited clearance according to claim 1 or 2, characterized in that: The cross-sections of the press-in hole (10) and the anchor static pressure pile (9) are both square, and the anchor static pressure pile is pressed into the press-in hole cylinder axis; the side length of the press-in hole is 8 cm to 12 cm longer than the side length of the anchor static pressure pile.
5. The road structure under a bridge with limited clearance according to claim 1 or 2, characterized in that: The pile support plate (5) is composed of ordinary concrete (14) and transverse ribs (15) and longitudinal ribs (16) cast in the ordinary concrete. The thickness of the pile support plate is 32 cm to 35 cm, and the grade of the ordinary concrete is 35 MPa to 40 MPa.
6. The road structure under a bridge with limited clearance according to claim 1 or 2, characterized in that: The distance between two adjacent press-in holes (10) in the longitudinal direction and the transverse direction on the pile support plate (5) is 2.5 m to 5.0 m.
7. The road structure under a bridge with limited clearance according to claim 4, characterized in that: The side length of the cross section of the anchor static pressure pile (9) is 18 cm to 30 cm, the length of the anchor static pressure pile is 3.0 m to 6.0 m, the length of the anchor static pressure pile extending into the pile support plate is 5 cm to 7 cm, and the grade of the micro-expansive concrete is 40 MPa to 45 MPa.