Drainage system for bridges and method for its construction

Abstract

The application discloses a drainage facility for a bridge and a construction method thereof, and relates to the technical field of bridge engineering. The drainage facility comprises water interception structures, the number of the water interception structures is the same as that of water discharge holes, each water interception structure is arranged in a ditch, and is located at the edge of a low point of a water discharge hole in the longitudinal direction of the bridge. The two sides of each water interception structure are connected with a protection wall and a track structure respectively. The height of the water interception structure is configured to be not less than a first height determined by the water discharge capacity of the ditch and a second height determined by the water discharge capacity of a water discharge pipe. The drainage facility and the construction method thereof are convenient to construct and have low construction cost. The drainage capacity can be effectively ensured, and the adverse effects of drainage defects on the bridge structure can be avoided. The construction and construction of the main structure of the bridge are hardly affected, and the drainage facility can be popularized and applied on a ballastless track bridge.

Description

Technical Field

[0001] This application relates to the field of bridge engineering technology, specifically to a drainage facility for bridges and its construction method. Background Technology

[0002] Drainage facilities are an important component of bridges. Currently, bridges typically use equally spaced drainage holes to ensure timely drainage from the bridge deck. The diameter and spacing of these drainage holes are mainly related to rainfall intensity, catchment area, and the longitudinal and transverse slopes of the bridge deck. Ballastless track bridges typically feature a herringbone slope, with the highest point of the bridge deck located within the mid-span, gradually decreasing in elevation towards the beam ends on both sides.

[0003] Under normal circumstances, a large amount of rainwater on a bridge will preferentially collect through the larger cross slope of the bridge deck and drain into the drainage holes on both sides of the bridge, with only a small amount of rainwater collecting at the beam ends through the longitudinal slope. However, when the longitudinal slope of the bridge deck is large, the rainfall intensity is high, or the drainage holes are blocked, the drainage holes cannot drain the water accumulated on the bridge in time, and the remaining rainwater will collect at the beam ends. The expansion joints at the beam ends will be affected by the erosion of rainwater, affecting their structural performance and durability. At the same time, rainwater leaking down onto the piers, abutments, and other substructures can easily cause corrosion of the main beams and supports. If the drainage facilities at the abutments are inadequate, the water collected on the bridge deck will be discharged directly from the abutments, causing erosion damage to the embankment. Summary of the Invention

[0004] In view of one of the defects in the prior art, the purpose of this application is to provide a drainage facility for bridges and a method for constructing it, so as to solve the problem that drainage defects cause adverse effects on bridge structures in the related art.

[0005] The first aspect of this application provides a drainage facility for a bridge, the bridge including a bridge deck, a protective wall and a track structure disposed on the bridge deck, a ditch forming between the protective wall and the track structure, the ditch having a plurality of drainage holes, each drainage hole having a drainage pipe installed therein; the drainage facility includes:

[0006] The number of water interception structures is the same as the number of drainage holes. Each of the above water interception structures is set in the above-mentioned ditch and is located at the low point edge of a drainage hole along the longitudinal direction of the bridge. The above-mentioned protective wall and track structure are respectively connected to both sides of each of the above water interception structures.

[0007] The height of the aforementioned water interception structure is configured to be no less than a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe.

[0008] In some embodiments, the height of the water-blocking structure is the larger of the first height and the second height, or the product of the larger value and a preset safety factor, wherein the preset safety factor is greater than 1.

[0009] In some embodiments, the aforementioned protective wall is a concrete protective wall, the aforementioned track structure is a ballastless track slab, and the aforementioned water-cutting structure is a concrete block.

[0010] In some embodiments, the side of the concrete block facing the adjacent drain hole is a downward sloping surface towards the drain hole.

[0011] In some embodiments, the concrete block is integrally cast with the bridge deck or connected by positioning steel bars, which are pre-embedded on the top surface of the bridge deck at the location of the concrete block.

[0012] In some embodiments, the protective wall is a steel structure protective wall, the track structure includes a concrete pad layer disposed on the bridge deck and a ballastless track slab disposed on the concrete pad layer, and the water interception structure is a steel baffle, which is connected to the steel structure protective wall on one side and to the concrete pad layer on the other side.

[0013] In some embodiments, the bottom of the steel baffle has small holes for water passage.

[0014] In some embodiments, the connection between the aforementioned water-cutting structure and the aforementioned protective wall and track structure is coated with waterproof adhesive.

[0015] A second aspect of this application provides a method for constructing the aforementioned drainage facility, comprising the steps of:

[0016] Obtain a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe, and determine the height of the water interception structure based on the larger of the first height and the second height.

[0017] A water-cutting structure is installed at the lowest point edge along the longitudinal direction of each drainage hole in the ditch, and the two sides of the water-cutting structure are respectively connected to the protective wall and the track structure.

[0018] In some embodiments, the first height is determined based on the principle that the drainage capacity of the ditch is equal to the design flow rate; the second height is determined based on the principle that the drainage capacity of the drain pipe is equal to the design flow rate.

[0019] The beneficial effects of the technical solution provided in this application include:

[0020] The drainage facility and its construction method for bridges disclosed in this application involve setting intercepting structures at the lowest point edge along the longitudinal direction of the bridge at each drainage hole within the ditch. The height of these intercepting structures is not lower than a first height determined by the ditch's drainage capacity and a second height determined by the drainage pipe's drainage capacity. This allows the intercepting structures to segmentally intercept the longitudinal water flow converging towards the beam ends of the bridge, interfering with the distribution of rainfall flow and reducing the amount of water flowing towards the beam ends. Simultaneously, the intercepting structures can also collect rainwater at the drainage pipes, increasing the head pressure difference at the drainage pipes and improving their drainage capacity, thus preventing the impact of water accumulation on the bridge structure's durability. Therefore, this application not only offers convenient construction and low construction costs but also effectively ensures drainage capacity, avoiding adverse effects on the bridge structure caused by drainage defects, and has almost no impact on the construction of the main bridge structure, making it suitable for widespread application on ballastless track bridges. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the installation of the concrete stop in an embodiment of this application;

[0023] Figure 2 This is a cross-sectional view of the concrete block installation in an embodiment of this application;

[0024] Figure 3 for Figure 2 Sectional view along line AA;

[0025] Figure 4 This is a schematic diagram of the installation of the steel baffle in an embodiment of this application;

[0026] Figure 5 This is a cross-sectional view of the steel baffle installation in an embodiment of this application;

[0027] Figure 6 for Figure 5 Sectional view along the BB direction;

[0028] Figure 7 for Figure 6 Sectional view along the CC direction.

[0029] Figure label:

[0030] 1. Concrete retaining blocks; 2. Protective wall; 3. Ballastless track slab; 4. Drainage pipe; 5. Bridge deck; 6. Concrete subbase; 7. Steel retaining plate; 8. Positioning reinforcement; 9. Fence cover; 10. Structural reinforcement. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] like Figure 1 and Figure 4 As shown (the circled portion in the figure represents an enlarged view of the water-cutting structure installation area), this application embodiment provides a drainage facility for bridges, which is also applicable to ballastless track bridges. The bridge includes a bridge deck 5, a protective wall 2 and a track structure disposed on the bridge deck 5, and a ditch is formed between the protective wall 2 and the track structure. The ditch has multiple drainage holes, and each drainage hole is equipped with a drainage pipe 4.

[0033] The aforementioned drainage system includes multiple intercepting structures, the number of which is the same as the number of drainage holes. Each intercepting structure is located within the aforementioned ditch, and each intercepting structure is situated at the lowest point edge of a drainage hole along the longitudinal direction of the bridge. The aforementioned protective wall 2 and the track structure are connected to both sides of each intercepting structure.

[0034] The height of the aforementioned water interception structures is configured to be no less than a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe 4. That is, each water interception structure is located between the protective wall 2 and the track structure, and its height is jointly determined by the drainage capacity of the ditch between the protective wall 2 and the track structure, as well as the drainage capacity of the drainage pipe 4.

[0035] The drainage system of this embodiment, by setting intercepting structures at the lowest point edge along the longitudinal direction of the bridge at each drainage hole in the ditch, with the height of the intercepting structures not lower than a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe, achieves segmented interception of longitudinal water flow converging towards the beam end of the bridge, interfering with the distribution of rainfall flow and reducing the amount of water flowing towards the beam end. Simultaneously, the intercepting structures can also collect rainwater at the drainage pipe, increasing the head pressure difference at the drainage pipe and improving the drainage capacity of the drainage pipe, thereby avoiding the impact of water accumulation on the bridge structure's durability. Therefore, this application not only has convenient construction and low construction cost, but also effectively ensures drainage capacity, avoids adverse effects on the bridge structure caused by drainage defects, and hardly affects the construction of the main bridge structure, making it convenient for widespread application on ballastless track bridges.

[0036] Based on the above embodiments, in this embodiment, the height of the water interception structure is the larger of the first height and the second height, or the product of the larger value and the preset safety factor, wherein the preset safety factor is greater than 1.

[0037] In some embodiments, the height of the aforementioned water-blocking structure is the larger of a first height and a second height.

[0038] Preferably, considering a certain safety factor, the height of the above-mentioned water interception structure can be appropriately increased based on the theoretical height, that is, the height of the above-mentioned water interception structure is the product of the larger value of the first height and the second height and the preset safety factor.

[0039] Based on the above embodiments, in this embodiment, the water-cutting structure is determined according to the bridge deck type. When the bridge deck 5 is a concrete bridge deck, concrete blocks are preferred as the water-cutting structure, and when the bridge deck is a steel bridge deck, steel baffles are preferred.

[0040] In this embodiment, each drain hole is provided with a grate cover 9 that covers the drain pipe 4. To prevent water from accumulating between the water interception structure and the drain hole, the water interception structure should be positioned as close as possible to the grate cover 9 adjacent to the drain pipe, but without affecting the installation and opening of the grate cover.

[0041] like Figure 2-3 As shown, optionally, the protective wall 2 is a concrete protective wall, the track structure is a ballastless track slab 3, and the water-cutting structure is a concrete block 1. Preferably, the bridge deck 5 is a concrete bridge deck. One side of the concrete block 1 is connected to the concrete protective wall, and the other side of the concrete block 1 is connected to the ballastless track slab 3.

[0042] Preferably, the side of the concrete block 1 facing the adjacent drain hole is a downward sloping surface towards the drain hole. The water-blocking slope formed by the sloping surface of the concrete block 1 ensures that no water accumulates between the concrete block 1 and the drain pipe 4.

[0043] Optionally, the cross-section of the concrete block 1 is a right-angled trapezoid, and the internal steel bars can be configured according to structural requirements to prevent water flow from eroding and damaging it.

[0044] In this embodiment, to fix the concrete block, the concrete block 1 can be integrally cast with the bridge deck 5, or the concrete block 1 and the bridge deck 5 can be connected by positioning steel bars. When the concrete block 1 and the bridge deck 5 are connected by positioning steel bars, the positioning steel bars are pre-embedded on the top surface of the bridge deck 5 at the location of the concrete block 1.

[0045] like Figure 5-7As shown, optionally, the protective wall 2 is a steel structure protective wall, and the track structure includes a concrete pad 6 and a ballastless track slab 3. The concrete pad 6 is placed on the bridge deck 5, and the ballastless track slab 3 is placed on the concrete pad 6.

[0046] In this embodiment, the water-cutting structure is a steel baffle 7. One side of the steel baffle 7 is connected to a steel structure protective wall, and the other side of the steel baffle 7 is connected to a concrete cushion layer 6.

[0047] In this embodiment, the bridge deck 5 is a steel bridge deck, the bottom surface of the steel baffle 7 needs to be consistent with the cross slope of the bridge deck, and the bottom end of the steel baffle 7 is welded and fixed to the steel bridge deck.

[0048] Preferably, the bottom of the steel baffle 7 is provided with a small hole for water passage to ensure that no water accumulates between the steel baffle 7 and the drain pipe 4.

[0049] Based on the above embodiments, in this embodiment, the connection between the above-mentioned water interception structure and the above-mentioned protective wall 2 and track structure is coated with waterproof adhesive.

[0050] This application also provides a method for constructing the above-mentioned drainage facility, the method comprising the following steps:

[0051] S1. Obtain a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe 4, and determine the height of the intercepting structure based on the larger of the first height and the second height.

[0052] S2. A water interception structure is installed at the lowest point edge along the longitudinal direction of each drainage hole in the ditch, and the two sides of the water interception structure are respectively connected to the protective wall 2 and the track structure.

[0053] In this embodiment, the first height is determined based on the principle that the drainage capacity of the ditch is equal to the design flow rate; the second height is determined based on the principle that the drainage capacity of the drainage pipe 4 is equal to the design flow rate.

[0054] Due to the presence of the intercepting structure, the cross-section of the ditch can be considered rectangular, and the theoretical height of the intercepting structure is the height of the cross-section. Therefore, according to the ditch's drainage capacity Q... c1 The first height h1 is determined based on the principle of being equal to the design runoff Q. The formula for calculating the drainage capacity of the ditch is as follows:

[0055]

[0056] In the formula: n is the roughness coefficient of the trench wall, which can be obtained by looking up the relevant standard table; b is the lateral distance (m) between the protective wall and the track structure; I is the longitudinal slope of the bridge deck.

[0057] After appropriate transformation, the first formula is formed: Kh1 5 -4h12 -4bh1-b 2 =0.

[0058] in, The first formula above is a quintic equation in one variable, which can be solved quickly using the Newton-Raphson iterative method or a graphical method to obtain h1.

[0059] The designed runoff volume Q = 16.67Ψq p,t F.

[0060] In the formula: q p,t The design return period and rainfall duration represent the average rainfall intensity (mm / min); Ψ is the runoff coefficient, which can be obtained from relevant standards; F is the catchment area (km²). 2 ).

[0061] The average rainfall intensity q within the above design return period and rainfall duration p,t =c p c t q 5,10 .

[0062] In the formula: q 5,10 The standard rainfall intensity (mm / min) with a 5-year return period and a 10-minute rainfall duration; c p c is the conversion factor for the return period. t q is the rainfall duration conversion factor. 5,10 c p and c t All of these can be obtained by consulting relevant standards and tables.

[0063] Water discharge capacity Q from the drain pipe c2 The second height h2 is determined based on the principle of being equal to the design flow rate Q. The formula for calculating the drainage capacity of the drain pipe is:

[0064]

[0065] In the formula: d is the diameter of the drain pipe (m); g is the acceleration due to gravity (m / s²). 2 ); ζ represents the flow rate of the trash rack (i.e., the rack cover). After appropriate transformation, the second formula is formed:

[0066]

[0067] In this embodiment, the height of the water-blocking structure is taken as the larger value of h1 and h2, that is, h = max(h1, h2).

[0068] Specifically, when the bridge deck is paved with concrete bridge panels and equipped with concrete protective walls and ballastless track slabs, a concrete block 1 can be set at the lowest point of the longitudinal direction of the drainage hole. The concrete block 1 is preferably a right-angled trapezoidal cross-section concrete block, and the concrete block 1 is located between the concrete bridge panel, the concrete protective wall 2 and the ballastless track slab 3.

[0069] In the longitudinal direction of the bridge, to secure the concrete stop 1, the concrete bridge deck and the concrete stop 1 can be cast together. Alternatively, two to three positioning steel bars 8 of a certain length can be pre-cast on the concrete bridge deck at the center of the bottom surface of the concrete stop 1. After the concrete bridge deck is cast, the concrete stop 1 is then cast, and the extended positioning steel bars 8 connect the concrete bridge deck and the concrete stop 1, thus securing the concrete stop 1. In the transverse direction of the bridge, the concrete stop 1 is perpendicularly connected to the concrete retaining wall 2 and the ballastless track slab 3 without gaps. Waterproof sealant is applied at the junction between them to prevent water seepage caused by the concrete stop 1 detaching from the concrete retaining wall or the ballastless track slab 3 during bridge operation.

[0070] In this embodiment, a groove and a drainage hole communicating with the groove are formed at the lowest point of the cross slope of the concrete bridge deck. The groove opening is larger than the drainage hole to facilitate the placement of the grating cover 9. The drainage pipe 4 is installed in the drainage hole. The diameter of the grating cover 9 is not less than the diameter of the drainage pipe 4. The grating cover 9 is placed in the groove of the concrete bridge deck and covers the drainage pipe 4. The top surface of the grating cover 9 is a certain distance lower than the top surface of the concrete bridge deck.

[0071] The concrete block 1 is a right-angled trapezoid with a cross-section of approximately 10cm wide at the top and approximately 15cm wide at the bottom. Its height is determined based on the first and second heights mentioned above. The concrete block 1 has an internal framework composed of reinforcing steel bars 10. The concrete block 1 is positioned as close as possible to the edge of the drainage hole, but without affecting the installation and opening of the grate cover 9.

[0072] When a steel structure protective wall and a concrete pad 6 are installed on the steel bridge deck, a steel baffle 7 can be installed at the lowest point of the longitudinal direction of the drainage hole. The steel baffle 7 is a steel plate of a certain thickness and is located between the steel bridge deck, the steel structure protective wall, and the concrete pad 6.

[0073] In this embodiment, a drainage hole is opened at the lowest point of the cross slope of the steel bridge deck. One end of the steel baffle 7 is tightly connected to the concrete pad 6, and waterproof adhesive is applied to the junction of the two. The other end of the steel baffle 7 is welded to the inner side of the steel structure protective wall to block the water flow between the steel structure protective wall and the concrete pad 6, and to guide the water into the drainage hole along the cross slope of the bridge deck. Optionally, waterproof adhesive can also be applied between the steel baffle 7 and the steel structure protective wall to further prevent water seepage. The steel baffle 7 is vertically welded to the steel bridge deck. The drainage pipe 4 is installed in the drainage hole and covered with a grate 9. The diameter of the grate 9 is the same as the outer diameter of the drainage pipe 4, and the top surface of the grate 9 is a certain distance lower than the top surface of the steel bridge deck. The shape of the bottom edge of the steel baffle 7 is determined by the cross slope of the steel bridge deck, and the thickness can be about 10mm. The steel baffle 7 is placed as close as possible to the edge of the drainage hole, but without affecting the installation and opening of the grate 9.

[0074] The construction method of this embodiment is applicable to the aforementioned drainage facilities. It uses multiple intercepting structures to segmentally intercept the longitudinal water flow converging towards the beam ends of the bridge, interfering with the distribution of rainfall flow, reducing the amount of water flowing towards the beam ends, and converging rainwater at the drainage pipes, increasing the head pressure difference at the drainage pipes and improving their drainage capacity. This drainage facility is not only convenient to construct and has low construction costs, but it also effectively ensures drainage capacity and avoids adverse effects on the bridge structure caused by drainage defects.

[0075] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0076] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0077] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A drainage system for bridges, characterized in that, The bridge includes a bridge deck (5), a protective wall (2) and a track structure installed on the bridge deck (5), and a ditch is formed between the protective wall (2) and the track structure. The ditch has multiple drainage holes, and each drainage hole is equipped with a drainage pipe (4). The drainage facilities include: The number of water-cutting structures is the same as the number of drainage holes. Each water-cutting structure is set in the ditch and is located at the low edge of a drainage hole along the longitudinal direction of the bridge. The protective wall (2) and the track structure are connected to both sides of each water-cutting structure. The height of the intercepting structure is configured to be no less than a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe (4).

2. The drainage facility for bridges as described in claim 1, characterized in that, The height of the water interception structure is the larger of the first height and the second height, or the product of the larger value and a preset safety factor, wherein the preset safety factor is greater than 1.

3. The drainage facility for bridges as described in claim 1, characterized in that: The protective wall (2) is a concrete protective wall, the track structure is a ballastless track slab (3), and the water-cutting structure is a concrete block (1).

4. The drainage facility for bridges as described in claim 3, characterized in that: The side of the concrete block (1) facing the adjacent drain hole is a downward sloping surface towards the drain hole.

5. The drainage facility for bridges as described in claim 3, characterized in that: The concrete block (1) is integrally cast with the bridge deck (5) or connected by positioning steel bars, which are pre-embedded on the top surface of the bridge deck (5) at the concrete block (1).

6. The drainage facility for bridges as described in claim 1, characterized in that: The protective wall (2) is a steel structure protective wall. The track structure includes a concrete pad (6) set on the bridge deck (5) and a ballastless track slab (3) set on the concrete pad (6). The water interception structure is a steel baffle (7), which is connected to the steel structure protective wall on one side and to the concrete pad (6) on the other side.

7. The drainage facility for bridges as described in claim 6, characterized in that: The bottom of the steel baffle (7) has a small hole for water passage.

8. The drainage facility for bridges as described in claim 1, characterized in that: The connection between the water-cutting structure and the protective wall (2) and the track structure is coated with waterproof adhesive.

9. A method for constructing the drainage facility according to claim 1, characterized in that, It includes the following steps: Obtain a first height determined by the drainage capacity of the ditch and a second height determined by the drainage capacity of the drainage pipe (4), and determine the height of the water interception structure based on the larger of the first height and the second height; A water-cutting structure is installed at the lowest point edge along the longitudinal direction of each drainage hole in the ditch, and the two sides of the water-cutting structure are respectively connected to the protective wall (2) and the track structure.

10. The method for constructing the drainage facility as described in claim 9, characterized in that: The first height is determined based on the principle that the drainage capacity of the ditch is equal to the design runoff. The second height is determined based on the principle that the drainage capacity of the drain pipe (4) is equal to the design flow rate.

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