A cross-river bridge renovation process for reducing the water-blocking effect

Abstract

The present invention discloses a cross-river bridge reconstruction process for reducing the water-blocking effect. The cross-river bridge has existing pile foundations and includes the following steps: Step S1, excavate the silt under the original cross-river bridge to the bottom elevation of the newly cast bearing platform, and pour a newly cast bearing platform around the existing pile foundations of the cross-river bridge. The newly cast bearing platform and the existing pile foundations of the original cross-river bridge are connected as a whole; Step S2, erect a temporary pier on the newly cast bearing platform; Step S3, demolish the old bearing platform and the old pier columns; Step S4, set new pier columns on the newly cast bearing platform. The number of the new pier columns is less than the number of the old pier columns. In the present invention, a newly cast bearing platform is poured at the location of the existing pile foundations as an operation platform for the reconstruction of the bridge lower structure, without the need to build an additional operation platform for pier replacement construction, so that the existing pile foundations and the newly cast bearing platform are fully utilized. In addition, the present invention adopts a structural form in which the existing pile foundations penetrate the newly cast bearing platform and uses two new connection methods between the two to ensure the reliable connection between the existing piles and the newly cast bearing platform.

Description

Technical Field

[0001] The present invention relates to the field of river-crossing bridge reconstruction for reducing water-blocking effect, and more particularly to a river-crossing bridge reconstruction process for reducing water-blocking effect. Background Art

[0002] River-crossing bridges inevitably affect river flows, primarily due to the water-blocking effect of structures such as piers within the bridge's substructure. Initially, the bridge's substructure's water-blocking effect meets regulatory requirements. However, when the waterway is upgraded, the required water-blocking area of the bridge's substructure increases. Alternatively, when a bridge ages and new reinforcement structures are added, the water-blocking area increases. These situations can cause the bridge's water-blocking effect to fail regulatory requirements, necessitating renovation of the existing bridge.

[0003] The traditional method of bridge substructure reconstruction requires first dismantling the original old structure to ensure construction space for casting the new structure. During this process, a temporary work platform must be set up to replace the bridge piers, which also consumes a lot of manpower and material resources.

[0004] Therefore, when necessary, a relatively simple and low-cost river-crossing bridge reconstruction process is provided to reduce the water-blocking effect of the bridge itself. Summary of the Invention

[0005] To achieve these objectives and other advantages according to the present invention, a preferred embodiment of the present invention provides a process for reconstructing a river-crossing bridge to reduce water-blocking effect, wherein the river-crossing bridge has an existing pile foundation, and the process for reconstructing the river-crossing bridge comprises the following steps:

[0006] Step S1: excavating the silt beneath the original river-crossing bridge to the bottom elevation of a new cap, wherein the top of the new cap is vertically located below the top of the existing pile foundation, and the new cap is cast around the periphery of the existing pile foundation, wherein the new cap is integrally connected to the existing pile foundation of the original river-crossing bridge;

[0007] Step S2: erecting temporary piers on the newly cast cap to temporarily support the old bridge cap beam located above the newly cast cap;

[0008] Step S3, dismantling the old cap and old pier;

[0009] Step S4: setting new piers on the newly cast cap to support the old bridge cap beam located above the newly cast cap;

[0010] The number of the new piers is less than the number of the old piers.

[0011] Preferably, in the above-mentioned river-spanning bridge reconstruction process for reducing water-blocking effect, the newly cast foundation is located below the mud surface of the riverbed.

[0012] Preferably, in the process for reconstructing a river-spanning bridge to reduce water-blocking effect, the new pier and the existing pile foundation are coaxial.

[0013] Preferably, in the process for reconstructing a river-crossing bridge to reduce the water-blocking effect, in step S1, the silt beneath the original river-crossing bridge is excavated by using a steel sheet pile cofferdam construction method.

[0014] Preferably, the river-crossing bridge reconstruction process for reducing water-blocking effect further comprises:

[0015] Step S5: dismantle the temporary piers and steel cofferdams.

[0016] Preferably, in the process for reconstructing a river-crossing bridge to reduce the water-blocking effect, in step S1, casting a new cap specifically includes the following operations:

[0017] First, a wedge-shaped surface is chiseled out on the protective layer of the existing pile foundation, wherein the wedge-shaped surface does not exceed the thickness range of the protective layer of the existing pile foundation, and the top and bottom of the wedge-shaped surface are respectively flush with the top elevation and the bottom elevation of the newly cast platform. The wedge-shaped surface surrounds the outer side surface of the existing pile foundation, and the wedge-shaped surface is gradually inclined from bottom to top towards the axis of the existing pile foundation, and then the newly cast platform is cast on the outside of the wedge-shaped surface of the existing pile foundation.

[0018] Preferably, in the above-mentioned river-crossing bridge reconstruction process for reducing water-blocking effect, a plurality of rings of steel bars are circumferentially arranged on the wedge-shaped surface.

[0019] Preferably, in the process for reconstructing a river-crossing bridge to reduce the water-blocking effect, in step S1, casting a new cap specifically includes the following operations:

[0020] First, a wedge-shaped surface is chiseled out on the protective layer of the existing pile foundation. The wedge-shaped surface does not exceed the thickness of the protective layer of the existing pile foundation, and the wedge-shaped surface is flush with the top elevation and the bottom elevation of the newly cast platform. The wedge-shaped surface surrounds the outer side surface of the existing pile foundation, and the wedge-shaped surface is inclined from bottom to top gradually approaching the axis of the existing pile foundation. Then, a clamp is installed on the outer side of the wedge-shaped surface of the existing pile foundation, and the inner side surface of the clamp fits and clamps the wedge-shaped surface, and then the newly cast platform is cast on the outer side of the clamp.

[0021] Preferably, in the process for reconstructing a river-crossing bridge to reduce the water-blocking effect, a plurality of angle steels distributed at intervals are provided on the outer side surface of the hoop.

[0022] The present invention has at least the following beneficial effects: When reconstructing the lower structure of a bridge, a newly cast bearing platform is poured at the original pile foundation, eliminating the need to build an additional working platform for pier replacement construction, thus making full use of the original pile foundation and the newly cast bearing platform. In addition, the present invention adopts a structural form in which the existing pile foundation penetrates the newly cast bearing platform, and two new connection methods between the newly cast bearing platform and the existing pile foundation are used to ensure a reliable connection between the existing pile and the newly cast bearing platform.

[0023] Other advantages, objectives, and features of the present invention will be partially reflected in the following description and partially understood by those skilled in the art through the research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a construction schematic diagram of step S1 in an embodiment of the present invention.

[0025] Figure 2 It is a construction schematic diagram of step S2 in an embodiment of the present invention.

[0026] Figure 3 It is a construction schematic diagram of step S3 in an embodiment of the present invention.

[0027] Figure 4 It is a construction schematic diagram of step S4 in an embodiment of the present invention.

[0028] Figure 5 It is a construction schematic diagram of step S5 in an embodiment of the present invention.

[0029] Figure 6 It is a connection schematic diagram of the newly cast bearing platform and the existing pile foundation in an embodiment of the present invention.

[0030] Figure 7 It is a connection schematic diagram of the newly cast bearing platform and the existing pile foundation in another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] The following further elaborates on the present invention with reference to the accompanying drawings, enabling those skilled in the art to implement it based on the description in the specification.

[0032] The following description is used to disclose the present invention so that those skilled in the art can implement it. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description can be applied to other embodiments, variations, improvements, equivalent solutions, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0033] Those skilled in the art should understand that in the disclosure of the present invention, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These 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. Therefore, the above terms should not be construed as limiting the present invention.

[0034] It can be understood that the term "one" should be understood as "at least one" or "one or more". That is, in one embodiment, the number of one element can be one, while in other embodiments, the number of this element can be multiple. The term "one" should not be construed as a limitation on the quantity.

[0035] The two main factors affecting the water-blocking effect are the water-blocking ratio and the flow velocity. The water-blocking ratio refers to the ratio of the area blocked by structures such as bridge piers and caissons of a wading bridge (the projected area in the water flow direction) to the total area of the river channel below a designed flood level. For a cross-river bridge, it is necessary to consider reducing the water-blocking ratio of piers, caissons, and reinforcement structures to reduce the water-blocking effect. For this purpose, the present invention proposes the following two methods to weaken the water-blocking effect: First, reduce the water-blocking ratio of the piers. Since the total area of the river channel below a fixed flood level remains unchanged, reducing the water-blocking ratio of the piers and reinforcement structures is equivalent to reducing their water-blocking area, and it is necessary to transform the lower structure to reduce the number of piers or cancel the reinforcement structure. Second, lower the elevation of the caisson, that is, move the caisson downward. Since the water flow velocity is smaller closer to the bottom of the water, lowering the elevation of the caisson can weaken its water-blocking effect.

[0036] Specifically, as Figures 1-7 shown, a preferred embodiment of the present invention provides a cross-river bridge reconstruction process for reducing the water-blocking effect. The cross-river bridge has existing pile foundations 100, and the cross-river bridge reconstruction process includes the following steps:

[0037] Step S1: Excavate the silt under the existing cross-river bridge to the bottom elevation of the newly cast caisson 200. The top of the newly cast caisson 200 is vertically below the top of the existing pile foundation 100, and pour the newly cast caisson 200 around the existing pile foundation 100 of the existing cross-river bridge, and connect the newly cast caisson 200 and the existing pile foundation 100 of the existing cross-river bridge into one body;

[0038] Among them, in step S1, the silt under the existing cross-river bridge is excavated by means of steel sheet pile cofferdam construction.

[0039] Step S2: Erect a temporary pier 300 on the newly cast caisson 200 to temporarily support the old bridge deck beam 400 above the newly cast caisson 200;

[0040] Step S3: Demolish the old bearing platform 500 and the old pier column 600;

[0041] Step S4: Install a new pier column 700 on the newly cast bearing platform 200 to support the old bridge capping beam 400 above the newly cast bearing platform 200. The new pier column and the existing pile foundation are coaxial. Among them, the number of new pier columns is less than that of the old pier columns. Among them, the newly cast bearing platform 200 is located below the riverbed mud surface, so as to eliminate the water blocking effect of the bearing platform.

[0042] Step S5: Demolish the temporary pier 300 and the steel cofferdam.

[0043] In the above implementation, by reducing the number of pier columns (specifically, the number of new pier columns is less than that of the old pier columns), the water blocking ratio of the piers is reduced. In this way, the water blocking ratio between the piers and the reinforcement structure can be reduced, which is equivalent to reducing its water blocking area, thereby achieving the purpose of reducing the water blocking effect. At the same time, the method of lowering the bearing platform is also adopted to reduce the water blocking effect. It should be noted that in the conventional bridge renovation, the sizes of the new pier columns and the old pier columns are generally the same and will not change greatly.

[0044] Considering that the length of the traditional pile foundation extending into the bearing platform is short, and the internal bent-up steel bars are used to ensure the stable connection between the two. In the above implementation, due to the downward movement of the newly cast bearing platform, if the bearing platform is still set at the original height, the problem that the pile foundation needs to penetrate the bearing platform to form a connection will be faced. Moreover, considering that it is impossible to set steel bars inside the pile foundation for the connection between the two. To solve this technical problem and ensure the stability of the pile and the bearing platform under this casting method, this application provides two technical solutions.

[0045] In step S1, when casting the newly cast bearing platform 200, the following operations are specifically included:

[0046] First, a wedge-shaped surface 110 is chiseled out on the protective layer of the existing pile foundation 100. The wedge-shaped surface does not exceed the range of the protective layer thickness of the existing pile foundation, and the top and bottom of the wedge-shaped surface are respectively flush with the top elevation and the bottom elevation of the newly cast bearing platform. The wedge-shaped surface 110 surrounds the outer side surface of the existing pile foundation 100 in a circle, and the wedge-shaped surface 110 gradually inclines upward and approaches the axis of the existing pile foundation 100. Then, the newly cast bearing platform 200 is cast outside the wedge-shaped surface 110 of the existing pile foundation 100. A number of rings of steel bars 120 are arranged circumferentially on the wedge-shaped surface.

[0047] In the above-mentioned implementation scheme, the connection method using the wedge self-locking structure supplemented by circumferential reinforcing bars: First, a wedge surface is chiseled out within the protective layer of the existing pile foundation, and then the bearing platform is poured, so that a preliminary self-locking effect is formed between the bearing platform and the wedge surface of the existing pile foundation. At the same time, since a reaction force perpendicular to the wedge surface of the pile foundation will be generated between the wedge surface of the pile foundation and the newly poured bearing platform, circumferential reinforcing bars are arranged near the wedge surface to resist.

[0048] Second, first chisel out a wedge surface 110 on the protective layer of the existing pile foundation 100. The wedge surface does not exceed the thickness range of the protective layer of the existing pile foundation, and the wedge surface does not exceed the top elevation and bottom elevation of the newly poured bearing platform in the height direction. The wedge surface 110 surrounds the outer side surface of the existing pile foundation 100 in a circle, and the wedge surface 110 gradually inclines towards the axis of the existing pile foundation 100 from bottom to top. Then, install a hoop 800 outside the wedge surface 110 of the existing pile foundation 100. The inner side surface of the hoop 800 fits and holds tightly with the wedge surface 110. Then, pour the newly poured bearing platform 200 outside the hoop 800. A number of angle steels 810 are arranged at intervals on the outer side surface of the hoop 800, and reliable connection is formed by using the resistance generated by the angle steels.

[0049] The present invention pours a newly poured bearing platform 200 at the original pile foundation as an operation platform for the transformation of the bridge substructure, without the need to build an additional operation platform for pier replacement construction, so that the original pile foundation and the newly poured bearing platform are fully utilized. In addition, the present invention adopts the structural form in which the existing pile foundation 100 penetrates the newly poured bearing platform, and uses two new connection methods between the newly poured bearing platform and the existing pile foundation to ensure the reliable connection between the existing pile foundation and the newly poured bearing platform.

[0050] Although the implementation schemes of the present invention have been disclosed as above, it is not limited to only the applications listed in the specification and the implementation modes. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily achieved. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A cross-river bridge reconstruction process for reducing the water-blocking effect, the cross-river bridge having existing pile foundations, characterized in that, The cross-river bridge reconstruction process includes the following steps: Step S1: Excavate the silt under the existing cross-river bridge to the bottom elevation of the newly cast cap. The top of the newly cast cap is vertically below the top of the existing pile foundation. Pour the newly cast cap around the periphery of the existing pile foundation, and connect the newly cast cap and the existing pile foundation of the original cross-river bridge into one body; Step S2: Erect temporary piers on the newly cast cap to temporarily support the old bridge girder above the newly cast cap; Step S3: Demolish the old cap and old pier columns; Step S4: Set new pier columns on the newly cast cap to support the old bridge girder above the newly cast cap; The number of the new pier columns is less than the number of the old pier columns; In step S1, pouring the newly cast cap specifically includes the following operations: First, chisel out a wedge-shaped surface on the protective layer of the existing pile foundation. The wedge-shaped surface does not exceed the thickness range of the protective layer of the existing pile foundation, and the top and bottom of the wedge-shaped surface are respectively flush with the top elevation and bottom elevation of the newly cast cap. The wedge-shaped surface surrounds the outer side surface of the existing pile foundation in a circle, and the wedge-shaped surface gradually inclines upward and approaches the axis of the existing pile foundation; Then pour the newly cast cap outside the wedge-shaped surface of the existing pile foundation; several circles of steel bars are arranged circumferentially on the wedge-shaped surface; or Then install a hoop outside the wedge-shaped surface of the existing pile foundation. The inner side surface of the hoop fits and hugs the wedge-shaped surface, and then pour the newly cast cap outside the hoop; several angle steels are arranged at intervals on the outer side surface of the hoop.

2. The cross-river bridge renovation process for reducing the water-blocking effect according to claim 1, characterized in that, The newly cast cap is below the riverbed mud surface.

3. The cross-river bridge reconstruction process for reducing the water-blocking effect according to claim 1, characterized in that, The new pier column is coaxial with the existing pile foundation.

4. The cross-river bridge reconstruction process for reducing the water-blocking effect according to claim 1, characterized in that, In step S1, the silt under the existing cross-river bridge is excavated by means of steel sheet pile cofferdam construction.

5. The cross-river bridge renovation process for reducing the water-blocking effect according to claim 1, characterized in that, Further includes: Step S5: Demolish the temporary piers and steel cofferdams.

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