Roadbed based on flow-state fly ash filling

Abstract

The utility model provides a roadbed based on flow-state fly ash filling, which is suitable for a box-shaped culvert arranged on a base, original roadbed bodies are symmetrically arranged on two sides of the box-shaped culvert, and a side slope composed of a plurality of steps is formed on one side, close to the box-shaped culvert, of each original roadbed body. A filling roadbed is filled between the steps and the box-shaped culvert; the filling roadbed comprises a roadbed cushion layer and a roadbed filling layer which are sequentially arranged from bottom to top; the roadbed filling layer comprises a plurality of flow-state fly ash layers which are sequentially filled in the filling direction. Fly ash which is light in self weight, small in compressibility, fast in solidification and low in cost is mixed with cement, water and an additive to prepare flow-state fly ash for filling, so that the roadbed filling cost is low, and a stable roadbed structure is achieved; meanwhile, the first concrete layer is arranged on the surface of the side slope formed by the original roadbed to serve as a waterproof barrier, earthwork standard rooms do not need to be installed, the waterproof performance of the original roadbed is further enhanced, and meanwhile the roadbed transformation time and cost are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of roadbed, in particular to a roadbed based on fluidized fly ash filling. Background Art

[0002] A culvert is a drainage channel (water passage) built beneath the roadbed during highway construction to allow the highway to pass through a canal without obstructing traffic. This structure allows water to flow underneath the road. It is used to drain floodwaters across natural valleys and depressions, cross roads to serve as an elevated thoroughfare for people, livestock, and vehicles, or serve as a channel for agricultural irrigation.

[0003] The existing culvert roadbed needs to be backfilled during the roadbed reconstruction process. The backfill used is generally composed of soil, sand and gravel. However, the backfill used is generally made from locally sourced materials, which can easily cause soil erosion in the sourced areas and increase the cost of backfill. In addition, the soil and sand and gravel are heavy in themselves, which can easily cause the culvert roadbed to be heavy, highly compressible and slow to consolidate, adversely affecting the stability of the culvert roadbed and the culvert. Therefore, it is necessary to provide a culvert roadbed with a filler that is light in weight, low in compressibility, fast in consolidation, low in filling cost, and high in efficiency. Utility Model Content

[0004] Aiming at the technical problems in the prior art of heavy weight, high cost and low stability of roadbed filling materials, the utility model provides a roadbed based on fluidized fly ash filling.

[0005] A roadbed based on fluidized fly ash filling comprises a culvert arranged on a base, the culvert being a box-shaped culvert, original roadbeds being symmetrically arranged on both sides of the box-shaped culvert, and a side slope consisting of a plurality of steps formed on the original roadbed close to the box-shaped culvert; a first concrete layer is provided on the surface of the side slope; a filling roadbed is filled between the steps and the box-shaped culvert; the filling roadbed comprises a roadbed cushion layer and a roadbed filling layer arranged in sequence from bottom to top; the roadbed cushion layer is located above the base; the horizontal surface of the roadbed filling layer is flush with the top of the box-shaped culvert, and the roadbed filling layer comprises a plurality of fluidized fly ash layers filled in sequence along the filling direction; the fluidized fly ash layers are made by mixing cement, fly ash, water and admixtures; the roadbed filling layer is provided with a roadbed and a pavement structure layer in sequence along the direction away from the roadbed cushion layer.

[0006] Furthermore, the width of the steps is not less than two meters, and the steps are inclined inwardly by 4%.

[0007] Furthermore, the roadbed cushion layer is a crushed stone cushion layer or a second concrete layer.

[0008] Furthermore, the water content of the fly ash is not more than 35%; and the cement is silicate cement.

[0009] Furthermore, an anti-seepage geomembrane is provided on the first concrete layer.

[0010] Furthermore, the thickness of the fluidized fly ash layer is 40 to 60 cm.

[0011] Furthermore, a retaining wall is symmetrically provided on both sides of the box culvert.

[0012] Furthermore, the retaining walls each include a wall foundation and a wall body arranged on the wall foundation, the wall foundation includes a first wall foundation located on one side of the wall body and a second wall foundation located on the other side of the wall body, and the first wall foundation is located below the box culvert and the second wall foundation is located below the roadbed cushion layer.

[0013] Furthermore, it is characterized in that the degree of compaction from the base to the top surface of the roadbed is greater than 97%.

[0014] The beneficial effects of the utility model are as follows: the utility model provides a roadbed based on fluidized fly ash filling, comprising a box-shaped culvert arranged on a base, original roadbeds symmetrically arranged on both sides of the box-shaped culvert, and a side slope consisting of a plurality of steps formed on the original roadbed near the box-shaped culvert; a filling roadbed is filled between the steps and the box-shaped culvert; the filling roadbed comprises a roadbed cushion layer and a roadbed filling layer arranged sequentially from bottom to top; the roadbed filling layer comprises a plurality of fluidized fly ash layers filled sequentially along the filling direction; by using fly ash with light weight, low compressibility, fast consolidation and low cost to mix with cement, water and admixtures to make fluidized fly ash for filling, the roadbed not only has low filling cost but also has a stable roadbed structure; at the same time, a first concrete layer is provided on the side slope surface formed by the original roadbed as a waterproof barrier, eliminating the need to install geocells, further enhancing the waterproof performance of the original roadbed while saving time and cost for roadbed reconstruction, thereby facilitating the extension of the service life of the roadbed and improving the efficiency of roadbed reconstruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of a roadbed based on fluidized fly ash filling provided by the utility model;

[0016] Figure 2 This is a schematic diagram of the partial structure of the box culvert, retaining wall, filled roadbed and original roadbed provided by the utility model.

[0017] Figure ID

[0018] 1. Base; 2. Box culvert; 3. Original roadbed; 4. Slope; 41. Steps; 5. Fill roadbed; 51. Roadbed cushion layer; 52. Roadbed fill layer; 6. Roadbed; 7. Pavement structure layer; 8. Retaining wall; 81. Wall foundation; 811. First wall foundation; 812. Second wall foundation; 82. Wall. DETAILED DESCRIPTION

[0019] To help those skilled in the art better understand the present invention, the present invention is further described in detail below with reference to the accompanying drawings. The embodiments described herein are merely a portion of the present invention, not all of the present invention. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0020] refer to Figure 1 As shown, a roadbed based on fluidized fly ash filling is suitable for a culvert set on a base 1, wherein the culvert is a box-shaped culvert 2, and original roadbeds 3 are symmetrically arranged on both sides of the box-shaped culvert 2. The original roadbed 3 forms a slope 4 composed of several steps 41 on the side close to the box-shaped culvert 2.

[0021] Specifically, the width of the steps 41 is not less than two meters, and the steps 41 are all inclined inwardly by 4%; the slope of the original roadbed 3 on both sides of the box culvert 2 is 1:2.

[0022] By providing side slopes 4 consisting of several steps 41 on both sides of the box culvert 2 and controlling the width and inclination angle of the steps 41, this design helps to disperse the load on the existing roadbed 3, reduce stress concentration, and thus enhance the stability of the existing roadbed 3. Furthermore, the inclined design of the steps 41 also facilitates drainage and reduces rainwater erosion on the roadbed.

[0023] A first concrete layer (not shown) is provided on the surface of the slope 4. An impermeable geomembrane is placed on top of the first concrete layer. The first concrete layer acts as a waterproof barrier, further enhancing the waterproof performance of the existing roadbed. The impermeable geomembrane effectively prevents groundwater or rainwater from infiltrating the roadbed, protecting it from water damage and extending its service life. The first concrete layer and the impermeable geomembrane significantly improve the impermeability of the roadbed.

[0024] A filling roadbed 5 is built between the step 41 and the box culvert 2; the slope 4 can also disperse the contact pressure between the original roadbed 3 and the filling roadbed 5, thereby improving the stability of the joint surface between the original roadbed 3 and the filling roadbed 5 and reducing roadbed deformation and cracking problems caused by uneven soil compaction or foundation settlement. The filling roadbed 5 includes a roadbed cushion layer 51 and a roadbed filling layer 52 arranged in sequence from bottom to top; the roadbed cushion layer 51 is located above the base. In this embodiment, the back length Lb of the filling roadbed 5 is 5m, and the top filling length of the filling roadbed is (2D+5)m; where D is the straight-line distance between the inner bottom surface of the box culvert 2 and the outer top surface of the box culvert 2.

[0025] The roadbed cushion layer 51 is a crushed stone cushion layer or a second concrete layer. The crushed stone cushion layer has excellent water permeability and can quickly drain accumulated water from the roadbed, reducing water erosion and damage to the roadbed, and keeping the roadbed dry and stable. Furthermore, the crushed stone cushion layer can significantly increase the bearing capacity of the foundation through the interlocking and interlocking action between its particles. The second concrete layer has extremely high strength and stability, can withstand large loads and deformation without easily breaking, and has excellent waterproof properties, effectively preventing groundwater or rainwater from penetrating into the roadbed. In this embodiment, the roadbed cushion layer 51 is a second concrete layer.

[0026] The horizontal surface of the roadbed fill layer 52 is flush with the top of the box culvert 2 and comprises several layers of fluidized fly ash sequentially deposited along the filling direction. The fluidized fly ash layers are formed by mixing cement, fly ash, water, and admixtures. The fly ash has a moisture content of no more than 35%; the cement is Portland cement; and admixtures are a general term for external admixtures in the fluidized fly ash-cement mixture that activate fly ash activity, provide early strength, reduce water content, and provide micro-expansion, thereby improving the performance of the mixture.

[0027] Fly ash, an industrial byproduct, is primarily composed of SiO2, Al2O3, Fe2O3, and small amounts of CaO and MgO. As one of the largest industrial pollutants, fly ash currently has a low utilization rate and is inexpensive. A cement mixer or slurry pump is used to mix fly ash with Portland cement, water, and admixtures to produce fluid fly ash. The resulting fluidized fly ash not only has the characteristics of light weight, low compressibility, and rapid consolidation, ensuring the stability of the roadbed, but also, due to its good fluidity, can be more easily filled into every corner and crevice of the roadbed, reducing the manual tamping and compaction steps required in traditional filling methods, thereby improving filling efficiency. Furthermore, because the fluidized fly ash layer formed by filling with fluidized fly ash is light weight and highly stable, it is not necessary to install geocells on the outer surface of the slope 4 to meet the stability and bearing capacity requirements of the roadbed, saving time and cost in roadbed reconstruction and improving road reconstruction efficiency.

[0028] The thickness of the fluidized fly ash layer is 40 to 60 cm. In this embodiment, the thickness of the fluidized fly ash layer is 50 cm. The pouring of the previous layer should be carried out after the pouring of the next layer has completely set. The height of the steps is 100 cm. Each side slope 4 has three steps, meaning that each roadbed fill layer 52 includes six layers of fluidized fly ash, which are poured in sequence.

[0029] The roadbed filling layer 52 is provided with a roadbed 6 and a pavement structure layer 7 in sequence along a direction away from the roadbed cushion layer.

[0030] refer to Figure 2 As shown, a retaining wall 8 is symmetrically provided on both sides of the box-shaped culvert 2. The retaining wall 8 is used to fix the box-shaped culvert. Each retaining wall 8 includes a wall foundation 81 and a wall body provided on the wall foundation 81. The wall foundation 81 includes a first wall foundation 811 located on one side of the wall body 82 and a second wall foundation 812 located on the other side of the wall body 82. The first wall foundation 811, the second wall foundation 812, and the wall body 82 are an integrally cast structure. The first wall foundation 811 is located below the box-shaped culvert 3, and the second wall foundation 812 is located below the roadbed cushion layer 51 of the filled roadbed 5 on its side. One side of the wall body 82 is in close contact with the box-shaped culvert 3, and the other side is in close contact with one side of the filled roadbed 5 on its side.

[0031] The design of retaining walls 8, symmetrically arranged on either side of the box culvert 3, significantly enhances the stability of the box culvert 2 and the overall stability and safety of the culvert roadbed structure. By placing the first wall foundation 811 below the box culvert 3 and the second wall foundation 812 deep beneath the roadbed cushion, a close connection with the culvert and roadbed is achieved, enhancing the bearing capacity of the roadbed foundation and effectively preventing lateral displacement of the box culvert 3 and the filled roadbed 5.

[0032] Preferably, the degree of compaction from the base 1 to the top surface of the roadbed 6 is greater than 97%.

[0033] The utility model provides a roadbed based on fluidized fly ash filling. By using fly ash with light weight, low compressibility, fast consolidation and low cost to mix with cement, water and admixtures to make fluidized fly ash for filling, the roadbed not only has low filling cost but also has a stable roadbed structure. At the same time, a first concrete layer is provided on the surface of the slope 4 formed by the original roadbed as a waterproof barrier, and there is no need to install geocells on the surface of the slope 4, thereby further enhancing the waterproof performance of the roadbed, saving time and cost for roadbed reconstruction, and being conducive to extending the service life of the roadbed and improving the reconstruction efficiency of the roadbed.

[0034] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention and are not intended to limit the present invention to the specific embodiments described. Obviously, other modifications and variations may be made based on the contents of this specification. The embodiments selected and specifically described in this specification are intended to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. They are not intended to limit the present invention, and any simple variations of the present invention fall within the scope of protection of the present invention.

Claims

1. A roadbed based on fluidized fly ash filling, the roadbed being suitable for a culvert arranged on a substrate, characterized in that: The culvert is a box-shaped culvert, and original roadbeds are symmetrically arranged on both sides of the box-shaped culvert. The original roadbed forms a slope consisting of a plurality of steps near the box-shaped culvert; a first concrete layer is provided on the surface of the slope; A filling roadbed is built between the step and the box culvert; the filling roadbed includes a roadbed cushion layer and a roadbed filling layer arranged in sequence from bottom to top; the roadbed cushion layer is located above the base; the horizontal surface of the roadbed filling layer is flush with the top of the box culvert, and the roadbed filling layer includes a plurality of fluidized fly ash layers filled in sequence along the filling direction; the fluidized fly ash layer is made by mixing cement, fly ash, water and admixtures; the roadbed filling layer is provided with a road bed and a pavement structure layer in sequence along the direction away from the roadbed cushion layer.

2. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: The width of the steps is not less than two meters, and the steps are inclined inwardly by 4%.

3. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: The roadbed cushion layer is a crushed stone cushion layer or a second concrete layer.

4. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: An anti-seepage geomembrane is provided on the first concrete layer.

5. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: The thickness of the fluidized fly ash layer is 40 to 60 cm.

6. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: A retaining wall is symmetrically provided on both sides of the box culvert.

7. The roadbed based on fluidized fly ash filling according to claim 6, characterized in that: The retaining walls each include a wall foundation and a wall body arranged on the wall foundation, the wall foundation includes a first wall foundation located on one side of the wall body and a second wall foundation located on the other side of the wall, and the first wall foundation is located below the box culvert, and the second wall foundation is located below the roadbed cushion layer.

8. The roadbed based on fluidized fly ash filling according to claim 1, characterized in that: The degree of compaction from the base to the top surface of the roadbed is greater than 97%.

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