Cleaning and finishing method for red-layer mudstone roadbed bridge abutment transition section base

Abstract

The invention relates to the technical field of roadbed construction, in particular to a cleaning and finishing method for a red-layer mudstone roadbed bridge abutment transition section base, which comprises the following steps: S1, cleaning the surface of a foundation bed; s2, surveying and setting out; s3, layered excavation is conducted on the transition section, excavation is conducted to the unweathered rock layer face base, and a plurality of steps from the bridge abutment to the foundation bed are formed; s4, step finishing is conducted, specifically, concrete materials are adopted for finishing each step; and S5, performing layered backfilling. The steps are formed through excavation after the surface layer of the foundation bed in the transition section is cleaned, concrete material finishing is conducted on each step, it can be ensured that the structure of the area where each step is located is stable, the bearing capacity meets the design requirement, overall improvement of the stability of a base in the transition section is achieved, meanwhile, the lower steps play a role in stabilizing the upper steps along the slope face of the transition section, and the stability of the base is improved. A stable slope surface is formed in the transition section, landslide settlement is not prone to occurring in the operation period, an abutment is not prone to being affected, the overall stability of a roadbed is ensured, and the settlement occurrence probability is reduced.

Description

Technical Field

[0001] This invention relates to the field of roadbed construction technology, specifically to a method for cleaning and repairing the base of the bridge abutment transition section of a red mudstone roadbed. Background Technology

[0002] The stability of the high-speed railway subgrade is a crucial factor in ensuring the safe operation and lifespan of high-speed railways. Red mudstone is a rock structure formed by diagenesis of clay, silt, and other particles. In its natural state, it is mostly blocky or layered. When exposed to water, the cementitious materials soften and the clay minerals hydrate, making it prone to softening and disintegration. When constructing high-speed railways within red mudstone sections, the treatment of the subgrade is critical to ensuring the overall quality and stability of the subgrade, especially in the transition section from bridge abutments to the subgrade. The treatment of red mudstone not only affects the quality and stability of the subgrade but also impacts the bridge piers and abutments. However, current technology lacks specific methods for cleaning and repairing red mudstone subgrades, particularly for the transition section near bridge abutments. Existing methods for cleaning red mudstone subgrades mainly rely on conventional treatment methods for expansive soil subgrades, which are inefficient and cannot guarantee the overall stability of the red mudstone subgrade in the transition section near bridge abutments, making it prone to settlement during operation. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies, such as low efficiency in cleaning and repairing the foundation of red mudstone roadbeds, inability to guarantee the overall stability of the roadbed, and susceptibility to settlement during operation. This invention provides a method for cleaning and repairing the foundation of the bridge abutment transition section of red mudstone roadbeds.

[0004] This invention provides a method for cleaning and repairing the base of the bridge abutment transition section of a red mudstone roadbed, including: S1. Subgrade surface cleaning: Clean the surface layer of the subgrade in the transition section; S2. Surveying and setting out: Surveying and setting out to determine the excavation area; S3, Layered Excavation of Transition Section: Based on the excavation range determined in S2, excavate to the unweathered rock layer base, forming several steps from the abutment to the subgrade. S4. Step finishing: Each step is finished with concrete. S5. Layered backfilling: The transition section is backfilled in layers.

[0005] Preferably, the steps include several front steps along the slope of the transition section and several side steps excavated on both sides of the transition section. After the steps are adjusted, the transition section is not only stabilized in the slope direction, but the side slopes on both sides can also be stabilized through the side steps, which also provide a certain degree of waterproofing and erosion protection.

[0006] Preferably, the step modification includes using concrete to modify the parts of the step whose load-bearing capacity does not meet the design requirements. This ensures that each step has sufficient load-bearing capacity, preventing settlement during operation and improving the overall stability of the transition section base.

[0007] Preferably, the locations where the bearing capacity does not meet the design requirements are identified by verifying the foundation bearing capacity using a penetrometer on each step. By testing the foundation bearing capacity at each step with the penetrometer, it is ensured that the foundation bearing capacity at each step meets the design requirements. This also indirectly identifies potential areas within the step where the bearing capacity does not meet the design requirements, such as broken sections or pits, allowing for timely exposure of these areas and facilitating early repairs to improve the overall repair effect.

[0008] Preferably, the step repair includes chiseling open areas where the load-bearing capacity does not meet design requirements and then filling them with concrete. This ensures that the load-bearing capacity of each step meets design requirements and avoids settlement caused by areas with insufficient load-bearing capacity, such as broken sections or potholes.

[0009] Preferably, the step repair includes erecting a template, pouring a layer of concrete to cover the surface of each step, and then backfilling in layers after the surface concrete has cured properly. This achieves complete coverage of the surface of each step, sealing the edges of each step level to prevent rainwater from soaking the unweathered base and causing the red mudstone to disintegrate again, thereby improving the repair quality of each step level and enhancing the overall structural stability of the transition section.

[0010] Preferably, the layered backfilling includes backfilling the foundation pit between the first step and the abutment with concrete, up to the bottom of the first step; layered backfilling within the transition section step area using graded crushed stone mixed with 3% cement; and layered backfilling within the subgrade surface area using graded crushed stone mixed with 5% cement. Through the backfilling between the abutment and the transition section, a tight connection is achieved, preventing the transition section slope from directly exerting lateral forces on the abutment foundation. It also provides slope support for the multiple steps on the transition section, preventing landslides along the slope and ensuring the overall stability of the transition section. The remaining layered backfill materials isolate the transition section from rainwater and other erosion of the subgrade, preventing further collapse of the red mudstone and improving the overall structural stability of the transition section.

[0011] Preferably, the layered backfilling further includes conducting a set of compaction coefficient K and EVD tests after each layer is completed, and a set of K30 tests after each 60cm high layer is filled. This is to ensure that the construction quality of each backfill layer meets the design requirements.

[0012] Preferably, the cleaning of the transition section subgrade surface includes: cleaning debris and silt from the roadbed surface. This ensures clear surveying and setting-out markers, provides accurate construction locations, and improves construction efficiency.

[0013] Preferably, the layered excavation includes: using mechanical equipment to clear the surface to a depth of at least 30cm from the unweathered rock layer base, and then replacing this with manual clearing to the unweathered rock layer base. This is to avoid over-excavation and damage.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a method for cleaning and repairing the foundation of the bridge abutment transition section of red mudstone roadbed. By cleaning the surface of the foundation bed in the transition section and excavating to form steps, and then repairing each step with concrete material, the structural stability of the area where each step is located can be ensured, thereby achieving an overall improvement in the stability of the foundation in the transition section, ensuring the overall stability of the roadbed, and reducing the probability of settlement. 2. This invention provides a method for cleaning and repairing the base of the bridge abutment transition section of red mudstone roadbed. Along the slope of the transition section, the lower step plays a stabilizing role on the upper step, which can make the transition section have a stable slope and prevent landslides and settlements during operation. 3. This invention provides a method for cleaning and repairing the foundation of the transition section of a bridge abutment in red mudstone roadbed. By backfilling in layers within the transition section, the structural integrity of the bridge abutment to the surface of the subgrade can be ensured, making the overall structure of the transition section stable and less likely to affect the bridge abutment, thus ensuring the safe operation of the bridge. Attached Figure Description

[0015] Figure 1 This is a flowchart illustrating a method for cleaning and repairing the base of a bridge abutment transition section of a red mudstone roadbed, as described in Example 1.

[0016] Figure 2 This is a side view of the cross-section after the transition section was excavated in layers as described in Example 1.

[0017] Figure 3 This is a top view of the transition section after layered excavation as described in Example 1.

[0018] Figure 4 This is a side view of the cross-section after the transition section has been cleaned and trimmed as described in Example 1.

[0019] Marked in the image: 1-Bridge abutment, 2-Transition section, 3-Subgrade surface, 4-Unweathered rock layer base, 5-Step, 6-Longitudinal groove, 7-Side step. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0021] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0022] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0023] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0024] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0025] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0026] Example 1 like Figures 1-4 As shown, a method for cleaning and repairing the base of the bridge abutment transition section of a red mudstone roadbed includes: S1. Subgrade surface cleaning: Clean the surface layer of the subgrade in transition section 2; S2. Surveying and setting out: Surveying and setting out to determine the excavation area; S3, Transition Section 2 Layered Excavation: Based on the excavation range determined by S2, excavate to the unweathered rock layer base 4, forming several steps 5 from the abutment 1 to the foundation bed; S4, Step 5 Repair: Use concrete to repair each step 5; S5. Layered backfilling: Layered backfilling is carried out on transition section 2.

[0027] Corresponding to steps S1 and S2, cleaning the surface layer 3 of the transition section 2 subgrade includes: cleaning debris and silt from the subgrade surface to provide a clearly marked construction site for surveying and setting out, and conducting surveying and setting out on the cleaned subgrade surface.

[0028] Corresponding to step S3, a small excavator can be used to dig out part of the broken foundation surface 3, and a combination of mechanical and manual methods can be used to clean the weathered broken foundation surface down to the hard unweathered rock layer base 4, so as to expose the unweathered rock layer base 4. Several steps 5 are formed by excavating in layers on the unweathered rock layer base 4.

[0029] In an optional implementation, mechanical equipment can be used to clear the rock to a depth of at least 30cm from the unweathered rock base 4, and then manual clearing can be performed to the unweathered rock base 4. This is to avoid over-excavation and damage.

[0030] In an optional implementation, the top width of each step 5 can be determined by combining the predetermined height of the step 5 with the slope of the slope. The excavation range of the top surface of each step 5 can be determined by measuring and setting out. The excavation range areas divided by the measuring and setting out are removed by mechanical and manual chiseling to form several steps 5 excavated in layers along the slope of the transition section 2.

[0031] In optional implementations, such as Figure 2As shown, the height of each step 5 can be set to 0.6m. When the slope of the transition section 2 is 1:3 after excavation, the top width of each step 5 is 1.8m. The height of each step 5 can be obtained through geological exploration combined with numerical model simulation calculation.

[0032] In one or more implementations, such as Figures 2-3 The layered excavation includes forming several steps 5 in the slope direction of transition section 2, and several side steps 7 on both sides of the transverse direction of transition section 2. After being repaired, the steps 5 along the slope direction of transition section 2 can strengthen the overall structure of transition section 2, ensuring that the bearing capacity of each step 5 in transition section 2 meets the design requirements. The side steps 7 on both sides of the transverse direction of transition section 2, after being repaired, can prevent the soil on both sides of transition section 2 from continuing to collapse and exert force on transition section 2, and can also provide a certain water-proof protection effect within the range of transition section 2, making the overall structure of transition section 2 stable, less prone to further settlement, ensuring the overall stability of the roadbed, meeting the bearing capacity requirements, and reducing the probability of settlement.

[0033] In an optional embodiment, the side steps 7 may be set at the bottom of the slope of the transition section 2 according to the condition of the base on both sides of the transition section 2. The side steps 7 may be set flush with the top surface of the steps 5 in the slope direction of the transition section 2.

[0034] In an optional implementation, after layered excavation, the dust and debris formed during excavation can be cleaned up, and a penetrometer can be used to verify the foundation of each step 5 to ensure that the bearing capacity of the foundation at step 5 meets the design requirements. This indirectly identifies areas within step 5 where the bearing capacity does not meet the design requirements, such as broken sections or pits. By promptly excavating and exposing the broken sections or pits, it is possible to carry out advance local repairs, ensuring that each step meets the bearing capacity design requirements.

[0035] In an optional implementation, the repair of step 5 includes using concrete to repair areas of step 5 where the load-bearing capacity does not meet design requirements, such as broken or pothole areas. By using concrete to fill in areas where collapse or disintegration may occur, the load-bearing capacity of each step 5 is ensured to meet design requirements, thus preventing settlement caused by areas where the load-bearing capacity does not meet design requirements during subsequent operation.

[0036] In an optional implementation, the step 5 trimming includes erecting a formwork, pouring a layer of concrete to cover each step 5, and then backfilling in layers after the surface concrete has cured properly. This method of covering the surface of the steps 5 with concrete ensures a smooth surface at each level, prevents rainwater erosion, improves the trimming quality of each step 5, enhances the overall structural stability of the transition section 2, and ultimately ensures the overall stability of the roadbed, reducing the likelihood of settlement.

[0037] In an alternative implementation, the template can be fixed by drilling holes in the rock base of step 5 and then installing reinforcing bars. After the concrete is poured, the template can be removed by cutting the reinforcing bars.

[0038] In optional implementations, such as Figure 4 As shown, the layered backfilling includes backfilling the foundation pit between the first step 5 and the abutment 1 with concrete, up to the bottom surface of the first step 5. This ensures a tight connection between the abutment 1 and the transition section 2, making it less likely for the slope of the transition section 2 to exert direct lateral forces on the foundation of the abutment 1. This backfilling also provides support for the slope bottom of the multiple steps 5 on the transition section 2, preventing landslides along the slope direction and ensuring the overall stability of the transition section 2.

[0039] In an optional implementation, the layered backfilling includes layered filling of graded crushed stone mixed with 3% cement within the transition section 2 step 5 area, and layered filling of graded crushed stone mixed with 5% cement within the subgrade surface layer 3 area. This layered filling material isolates the base of the transition section 2 from rainwater and other erosion, preventing further collapse of the red mudstone and improving the overall structural stability of the transition section 2.

[0040] In an optional implementation, the layered backfilling also includes conducting a set of compaction coefficient K tests and EVD tests after each layer is completed, and a set of K30 tests after each 60cm high layer is filled, to ensure that the construction quality of each layer meets the design requirements.

[0041] This embodiment describes a method for cleaning and repairing the foundation of a bridge abutment transition section in red mudstone roadbed. After cleaning the surface layer 3 of the subgrade within the transition section 2, steps 5 are excavated. Each step 5 is then repaired with concrete, ensuring structural stability in the area where each step 5 is located and achieving an overall improvement in the foundation stability within the transition section 2. Simultaneously, along the slope of the transition section 2, the lower steps 5 stabilize the upper steps 5, ensuring a stable slope within the transition section 2 and reducing the likelihood of landslides and settlement during operation. Layered backfilling within the transition section 2 ensures the structural integrity from the bridge abutment 1 to the surface layer 3, making the overall structure of the transition section 2 stable and less likely to affect the bridge abutment 1, thus ensuring the safe operation of the bridge.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of cleaning and dressing a red-bed shale subgrade abutment transition section foundation, characterized by, The application relates to a method for constructing a transition section (2) of a bridge. S1, cleaning the surface of the bed: cleaning the surface of the bed (3) of the transition section (2); S2, measuring and setting out: measuring and setting out the range of excavation; S3, layer-by-layer excavation of the transition section (2): based on the range of excavation determined in S2, excavating to the unweathered rock layer base (4) to form several steps (5) from the abutment (1) to the bed; S4, step (5) trimming: trimming each step (5) with concrete material; S5, layer-by-layer backfilling: layer-by-layer filling of the transition section (2).

2. The method of claim 1, wherein the method further comprises: The steps (5) comprise several front steps along the slope surface of the transition section and several side steps (7) formed by excavation on the lateral sides of the transition section (2).

3. The method of claim 1, wherein the method further comprises: The step (5) trimming comprises trimming the parts with insufficient bearing capacity in the step (5) with concrete material.

4. The method of claim 3, wherein the method further comprises: The parts with insufficient bearing capacity are determined by using a feeler gauge to check the bed on each step (5).

5. The method of claim 3, wherein the method further comprises: The step (5) trimming comprises chiseling the parts with insufficient bearing capacity and filling them with concrete material.

6. The method of claim 3, wherein the method further comprises: The step (5) trimming comprises erecting a formwork, pouring surface layer concrete on each step (5) to cover the whole step, and then carrying out the layer-by-layer backfilling after curing of the surface layer concrete.

7. The method of claim 6, wherein the method further comprises, The layer-by-layer backfilling comprises backfilling the foundation pit with concrete between the first step (5) and the abutment (1) to the bottom surface of the first step (5), layer-by-layer filling with graded gravel mixed with 3% cement in the range of the steps (5) of the transition section (2), and layer-by-layer filling with graded gravel mixed with 5% cement in the range of the surface layer (3) of the bed.

8. The method of claim 7, wherein the method further comprises, The layer-by-layer backfilling further comprises carrying out a group of K detection and EVD detection after filling each layer, and carrying out a group of K30 detection after filling to a height of 60 cm.

9. The method of claim 1-8, wherein the method further comprises, The cleaning of the surface of the bed (3) of the transition section (2) comprises cleaning sundries and silt on the surface of the roadbed.

10. The method of claim 1-8, wherein the method further comprises, The layer-by-layer excavation comprises cleaning the bed to a position not less than 30 cm from the unweathered rock layer base (4) with mechanical equipment and replacing manual cleaning to the unweathered rock layer base (4).

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