Thin cement concrete roadbed and pavement structure based on fine-grained tailing soil

Abstract

The utility model relates to a thinned cement concrete roadbed and pavement structure based on fine-grained tailing soil, and belongs to the field of road engineering and environmental geotechnical engineering. The roadbed and pavement structure comprises a cement concrete surface layer, a cement stabilized macadam base layer, a thinned lime stabilized fine grain tailing soil subbase layer, a thinned lime stabilized fine grain tailing soil upper roadbed and a thinned lime stabilized fine grain tailing soil lower roadbed, the subgrade pavement structure is sequentially paved with a thinned lime-stabilized fine-grained tailing soil lower roadbed, a thinned lime-stabilized fine-grained tailing soil upper roadbed, a thinned lime-stabilized fine-grained tailing soil subbase layer, a cement-stabilized macadam base layer and a cement concrete surface layer from bottom to top. According to the thinned cement concrete roadbed pavement structure based on the fine-grained tailing soil, the thicknesses of the subbase layer, the upper roadbed and the lower roadbed are reduced through the higher mechanical property of the fine-grained tailing soil, so that the subbase layer, the upper roadbed and the lower roadbed are compacted better in the construction process, and the construction difficulty is reduced.

Description

Technical Field

[0001] This utility model relates to a thinned cement concrete roadbed and pavement structure based on fine-grained tailings soil, belonging to the fields of road engineering and environmental geotechnical engineering. Background Technology

[0002] Fine-grained tailings are a byproduct of iron ore beneficiation. After sorting, they represent the solid waste with the lowest content of the target component. They are generally fine powder with predominantly cohesive particles, exhibiting high mechanical strength and expansion properties. Currently, the large-scale stockpiling of tailings incurs additional costs for land acquisition, transportation, and landfill, increasing production costs for factories. Furthermore, this stockpiling not only occupies significant land resources but also poses environmental pollution and safety risks, potentially creating new pollutants during sedimentation. The massive earth and stone consumption in road construction provides a channel for tailings reduction. Their resource utilization can address the various problems caused by the current large-scale stockpiling of tailings, meet the huge material demands of road construction, reduce construction costs, and achieve both ecological and economic benefits.

[0003] The roadbed and pavement structure is a layered system that vertically divides the road into layers of varying thicknesses. From top to bottom, the roadbed and pavement structure layers are: surface layer, base course, subbase course, subbase layer, upper subgrade, and lower subgrade. The base course and subbase course primarily bear traffic loads and must possess high mechanical strength; therefore, various specifications and requirements stipulate very strict thickness and strength indicators for them. The subbase layer is the dividing layer between the pavement and the roadbed, and due to the different road construction materials of the two layers, it has various special functional requirements. The roadbed serves to bear loads and further transfer them downwards. Because it is thick and located at the bottom of the road structure layers, the loads transferred from the upper layers are unlikely to cause ultimate failure. The change in its modulus has a greater impact on the upper structure layers; therefore, its standards focus more on the California bearing ratio, i.e., the compression modulus. In summary, each layer has differentiated performance requirements due to its different functions, and the replacement of the original soil materials with fine-grained tailings soil should be carried out according to the needs of different layers.

[0004] Currently, most patents describe tailings soil as sandy soil primarily composed of magnetite, whose characteristics and performance differ significantly from fine-grained tailings soil, making it less relevant for comparison. Furthermore, there are no specific requirements or specifications regarding the thickness of structural layers. Therefore, there is a lack of technical means for treating fine-grained tailings soil in practical engineering. At the same time, fine-grained tailings soil possesses higher mechanical properties, far exceeding the basic requirements for each layer. The thickness requirements originally intended to ensure road performance actually become obstacles to construction in fine-grained tailings soil, increasing construction difficulty. Therefore, it is necessary to further select appropriate thicknesses to facilitate better compaction. Utility Model Content

[0005] This invention addresses the practical problems of large tailings soil inventory and the increased construction difficulty of fine-grained tailings soil due to the increased thickness of commonly used structural layers. It provides a thinner cement concrete pavement subgrade structure using fine-grained tailings soil as the main raw material.

[0006] This utility model provides a thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil. The subgrade and pavement structure includes a cement concrete surface layer, a cement stabilized crushed stone base layer, a thinned lime stabilized fine-grained tailings soil subbase layer, a thinned lime stabilized fine-grained tailings soil upper subgrade, and a thinned lime stabilized fine-grained tailings soil lower subgrade.

[0007] The roadbed and pavement structure consists of, from bottom to top, a thinned lime-stabilized fine-grained tailings soil subgrade, a thinned lime-stabilized fine-grained tailings soil upper subgrade, a thinned lime-stabilized fine-grained tailings soil base course, a cement-stabilized crushed stone base course, and a cement concrete surface course.

[0008] The thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil described in this utility model has a layer thickness of 8cm to 15cm for the thinned lime-stabilized fine-grained tailings soil subbase.

[0009] The thickness of the thinned lime-stabilized fine-grained tailings soil subgrade is 20cm;

[0010] The thickness of the thinned lime-stabilized fine-grained tailings subgrade is 40cm to 80cm.

[0011] The thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil described in this utility model has a lime dosage of 6% to 8% of the dry fine-grained tailings soil mass added to the thinned lime-stabilized fine-grained tailings soil subbase (3).

[0012] The amount of lime added to the thinned lime-stabilized fine-grained tailings soil roadbed (4) is 6% to 8% of the mass of the dry fine-grained tailings soil.

[0013] The amount of lime added to the thinned lime-stabilized fine-grained tailings soil subgrade (5) is 6% to 8% of the mass of the dry fine-grained tailings soil.

[0014] The thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil described in this utility model shall have a 7-day unconfined compressive strength of not less than 2 MPa for the thinned lime-stabilized fine-grained tailings soil subbase.

[0015] The thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil described in this utility model has a California bearing capacity ratio of not less than 20% between the thinned lime-stabilized fine-grained tailings soil upper subgrade and the thinned lime-stabilized fine-grained tailings soil lower subgrade.

[0016] The thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil described in this utility model has a maximum particle size of no more than 4.75 mm in the fine-grained tailings soil of the thinned lime-stabilized fine-grained tailings soil subbase, thinned lime-stabilized fine-grained tailings soil upper subgrade, and thinned lime-stabilized fine-grained tailings soil lower subgrade; the mass fraction of particles with a particle size of less than 0.075 mm in the fine-grained tailings soil is greater than 60%, the plasticity index is 17-19, and the organic matter content is less than 5%.

[0017] Beneficial effects

[0018] The present invention provides a thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil. By utilizing the superior mechanical properties of fine-grained tailings soil, the thickness of the subbase and upper and lower subgrades can be reduced, thereby facilitating better compaction during construction and reducing construction difficulty.

[0019] The present invention provides a thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil. It completely replaces the sand and gravel or soil materials in the traditional process of subbase and upper and lower roadbed with fine-grained tailings soil, improves the resource utilization rate of tailings soil, more effectively alleviates the environmental pollution caused by tailings soil accumulation, solves the problem of shortage of high-quality road construction resources, reduces the mining of natural crushed stone, and has good environmental benefits.

[0020] The present invention provides a thinned cement concrete roadbed and pavement structure based on fine-grained tailings soil. The fine-grained tailings soil used is solid waste generated during mineral processing. Apart from transportation costs, the remaining costs for road construction are basically zero, which can effectively reduce the cost of road construction and has good economic benefits. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this utility model or the prior art, the accompanying drawings used in the embodiments are briefly described below:

[0022] Figure 1 This is a schematic diagram of a thinned cement concrete subgrade and pavement structure based on fine-grained tailings soil.

[0023] Figure 2 Comparison of 7-day unconfined compressive strength test results for thinned fine-grained tailings subbase;

[0024] Figure 3 Comparison of California bearing ratio test results for upper and lower roadbeds of thinned fine-grained tailings;

[0025] Figure 4 A comparison chart of test results for the saturated swelling of the upper and lower roadbeds of the thinned fine-grained tailings.

[0026] Figure label:

[0027] 1: Commonly used cement concrete surface layer; 2: Commonly used cement stabilized crushed stone base course; 3: Thinned lime stabilized fine-grained tailings soil subbase course; 4: Thinned lime stabilized fine-grained tailings soil upper roadbed; 5: Thinned lime stabilized fine-grained tailings soil lower roadbed. Detailed Implementation

[0028] To make the objectives and technical solutions of the present utility model clearer, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0029] The following is combined Figure 1 Description of the roadbed and pavement structure of this utility model:

[0030] like Figure 1 As shown, this utility model consists of a common cement concrete surface layer 1, a common cement stabilized crushed stone base layer 2, a thinned lime stabilized fine-grained tailings soil subbase layer 3, a thinned lime stabilized fine-grained tailings soil upper roadbed 4, and a thinned lime stabilized fine-grained tailings soil lower roadbed 5, stacked from top to bottom.

[0031] The main features of the roadbed and pavement structure set by this utility model are: a thinned lime-stabilized fine-grained tailings soil subbase 3, a thinned lime-stabilized fine-grained tailings soil upper roadbed 4, a thinned lime-stabilized fine-grained tailings soil lower roadbed 5, and a commonly used cement-stabilized crushed stone base course with special permeability requirements.

[0032] Commonly used cement concrete surface layers include common cement concrete materials that meet the requirements of various specifications. Commonly used cement stabilized crushed stone base layers include common cement stabilized crushed stone materials that meet the requirements of various specifications. Fine-grained tailings soil has the characteristic of high expansibility. The permeability coefficient of cement stabilized crushed stone in commonly used cement stabilized crushed stone base layers should be less than 0.05 m / d.

[0033] The thickness of the thinned lime-stabilized fine-grained tailings soil subbase 3 is 8cm to 15cm.

[0034] The thickness of the thinned lime-stabilized fine-grained tailings soil upper subgrade 4 is 20cm. The thickness of the thinned lime-stabilized fine-grained tailings soil lower subgrade 5 is 40cm, and the thickness is 80cm under heavy and extremely heavy traffic conditions.

[0035] In the thinned lime-stabilized fine-grained tailings soil subbase 3, the added lime dosage is 6% to 8%. In the thinned lime-stabilized fine-grained tailings soil upper and lower subgrades, the added lime dosage is 6% to 8%.

[0036] The 7-day unconfined compressive strength of the thinned lime-stabilized fine-grained tailings soil subbase should not be less than 2 MPa. The California bearing capacity ratio of the upper and lower subgrades of the thinned lime-stabilized fine-grained tailings soil should not be less than 20%.

[0037] Material requirements and applicability:

[0038] The subgrade structure of the thinned cement concrete pavement based on fine-grained tailings soil has the following characteristics: the maximum particle size of the fine-grained tailings soil is no greater than 4.75 mm; the mass fraction of particles with a diameter of less than 0.075 mm in the fine-grained tailings soil is greater than 60%, the plasticity index is 17-19, and the organic matter content is less than 5%; the leaching concentration of copper in the fine-grained tailings soil is less than 26.77 μg / L, barium is less than 61.61 μg / L, chromium is less than 2.28 μg / L, cadmium is less than 2.28 μg / L, and lead is less than 0.20 μg / L. The lime used is quicklime, grade II or higher.

[0039] This utility model provides a thinned cement concrete pavement subgrade structure based on fine-grained tailings soil, applicable to urban roads of the following types and grades: main roads, secondary roads, and below.

[0040] The mechanical properties of the thinned lime-stabilized fine-grained tailings soil subbase were determined by a 7-day unconfined compressive strength test, and the target mix proportion used in actual road construction was selected.

[0041] The mechanical properties of the subgrade and upper and lower roadbeds of the thinned lime-stabilized fine-grained tailings soil were determined by the California bearing ratio test, and the target mix proportion used in actual road construction was selected.

[0042] The permeability coefficient requirement of commonly used cement-stabilized crushed stone base courses is determined by the saturation expansion rate of the thin lime-stabilized fine-grained tailings soil subbase and the thinned lime-stabilized fine-grained tailings soil upper and lower roadbeds.

[0043] Example 1:

[0044] This embodiment provides an implementation plan and target mix design scheme for a 7-day unconfined compressive strength test of a thinned lime-stabilized fine-grained tailings soil subbase. The main components include: fine-grained tailings soil with a moisture content of 10.8±1%, and lime at 6% of the dry fine-grained tailings soil mass. The preparation method for the materials and data includes the following steps:

[0045] Step S1: Crush and dry the fine-grained tailings soil until the moisture content is between 10.8 and 1%.

[0046] Step S2: Add 6% of the dry fine-grained tailings soil mass of lime to the fine-grained tailings soil with a moisture content of 10.8±1%, mix thoroughly, wrap with a waterproof membrane, and let stand for more than 24 hours.

[0047] Step S3: Put about 230g of fine tailings soil mixture mixed with lime into a Φ50mm×50mm mold and compact it with a hydraulic press.

[0048] Step S4: Wrap the compacted specimen with a waterproof membrane and place it in a curing chamber at a temperature of 20°C and a humidity of 98% for curing.

[0049] Step S5: Take out the specimen after 6 days of curing, remove the waterproof membrane covering the surface, and immerse it completely in water for 24 hours. Then, use a pavement strength tester to test the unconfined compressive strength and record the data.

[0050] Comparative Example 1:

[0051] Unlike Example 1, Comparative Example 1 used 2% dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 1. The required materials and data were prepared in the same manner.

[0052] Comparative Example 2:

[0053] Unlike Example 1, Comparative Example 2 added 4% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 1, and the required materials and data were prepared in the same manner.

[0054] Comparative Example 3:

[0055] Unlike Example 1, Comparative Example 3 added 8% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 1, and the required materials and data were prepared in the same manner.

[0056] Comparative Example 4:

[0057] Unlike Example 1, Comparative Example 4 used 10% dry fine-grained tailings soil as lime, while the rest was the same as in Example 1. The required materials and data were prepared in the same way.

[0058] Comparative Example 5:

[0059] Unlike Example 1, Comparative Example 5 added 12% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 1, and the required materials and data were prepared in the same manner.

[0060] Comparative Example 6:

[0061] Unlike Example 1, Comparative Example 6 added 14% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 1, and the required materials and data were prepared in the same manner.

[0062] Comparative Example 7:

[0063] Unlike Example 1, the soil in Comparative Example 7 was conventional clay with a particle composition similar to fine-grained tailings soil. The added lime was 6% of the dry conventional clay mass. The rest was the same as in Example 1, and the required materials and data were prepared in the same way.

[0064] The 7-day unconfined compressive strength data of Example 1 and Comparative Examples 1 to 7 were analyzed according to... Figure 2 As shown in the diagram, the mix proportions exceeding 0.5 MPa and exceeding Comparative Example 7 were selected as the alternative target mix proportions.

[0065] Furthermore, when there is more than one alternative target combination ratio, such as Figure 2 As shown, the mix proportion with the highest 7-day unconfined compressive strength is selected as the target mix proportion used in construction, i.e., Example 1.

[0066] Example 2:

[0067] This embodiment provides an implementation scheme and target mix design scheme for the California bearing ratio test of thinned lime-stabilized fine-grained tailings soil upper and lower subgrades. The main components include: fine-grained tailings soil with a moisture content of 10.8±1%, and lime at 6% of the dry fine-grained tailings soil mass. The preparation method for materials and data includes the following steps:

[0068] Step S1: Crush and dry the fine-grained tailings soil until the moisture content is between 10.8 and 1%.

[0069] Step S2: Add 6% of the dry fine-grained tailings soil mass of lime to the fine-grained tailings soil with a moisture content of 10.8±1%, mix thoroughly, wrap with a waterproof membrane, and let stand for more than 24 hours.

[0070] Step S3: Fill a 150mm×150mm mold with approximately 6300g of fine-grained tailings soil mixture containing lime into three layers, and compact each layer 98 times with a heavy compactor.

[0071] Step S4: Demold the compacted specimen, place four Φ150 annular pads on the top surface and immerse it completely in water.

[0072] Step S5: Take out the specimen that has been saturated with water for 3 days, and continuously penetrate it with a bearing ratio meter, recording the penetration depth and penetration pressure, so as to calculate the compression modulus at different penetration depths.

[0073] Step S6: Calculate the California bearing ratio based on the penetration pressure at penetration depths of 2.5 mm and 5 mm.

[0074] Comparative Example 8:

[0075] Unlike Example 2, Comparative Example 8 used 0% dry fine-grained tailings soil as the lime added, but otherwise it was the same as Example 2. The required materials and data were prepared in the same way.

[0076] Comparative Example 9:

[0077] Unlike Example 2, Comparative Example 9 added 2% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 2, and the required materials and data were prepared in the same manner.

[0078] Comparative Example 10:

[0079] Unlike Example 2, Comparative Example 10 added 4% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 2, and the required materials and data were prepared in the same manner.

[0080] Comparative Example 11:

[0081] Unlike Example 2, Comparative Example 11 used 8% dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 2. The required materials and data were prepared in the same manner.

[0082] Comparative Example 12:

[0083] Unlike Example 2, Comparative Example 12 added 10% of the mass of dry fine-grained tailings soil with lime. The rest was the same as in Example 2, and the required materials and data were prepared in the same manner.

[0084] Comparative Example 13:

[0085] Unlike Example 2, Comparative Example 13 added 12% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 2, and the required materials and data were prepared in the same manner.

[0086] Comparative Example 14:

[0087] Unlike Example 2, Comparative Example 14 used 14% dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 2. The required materials and data were prepared in the same manner.

[0088] Comparative Example 15:

[0089] Unlike Example 2, the soil in Comparative Example 15 was conventional clay with a particle composition similar to fine-grained tailings soil. The added lime was 6% of the dry conventional clay mass. The rest was the same as in Example 2, and the required materials and data were prepared in the same way.

[0090] The California occupancy ratios of Example 2 and Comparative Examples 8 to 15 were compared according to... Figure 3The diagram shows that a mix proportion exceeding 8% and exceeding the comparative proportion 15 is selected as the alternative target mix proportion.

[0091] Furthermore, when there is more than one alternative target combination ratio, such as Figure 3 As shown, the mix proportion with the highest load-bearing ratio in California is selected as the target mix proportion used in construction, i.e., Example 2.

[0092] Example 3

[0093] This embodiment provides an implementation plan for the test of saturated swelling rate of thinned lime-stabilized fine-grained tailings soil subbase and upper and lower roadbeds, and a judgment basis for the permeability coefficient requirements of commonly used cement-stabilized crushed stone base courses. It mainly includes: fine-grained tailings soil with a moisture content of 10.8±1%, and lime at 6% of the dry fine-grained tailings soil mass. The preparation method of materials and data includes the following steps:

[0094] Step S1: Crush and dry the fine-grained tailings soil until the moisture content is between 10.8 and 1%.

[0095] Step S2: Add 6% of the dry fine-grained tailings soil mass of lime to the fine-grained tailings soil with a moisture content of 10.8±1%, mix thoroughly, wrap with a waterproof membrane, and let stand for more than 24 hours.

[0096] Step S3: Fill a 150mm×150mm mold with approximately 6300g of fine-grained tailings soil mixture containing lime into three layers, and compact each layer 98 times with a heavy compactor.

[0097] Step S4: Demold and remove the compacted specimen, add a permeable plate to the top surface, install a dial indicator to measure the vertical volume change of the specimen, and place four Φ150 annular pads on the top of the permeable plate to completely immerse it in water.

[0098] Step S5: Measure the vertical volume change of the specimen after 3 days of water saturation, weigh it, record the experimental data, and calculate the water saturation expansion rate based on the vertical volume change.

[0099] Comparative Example 16:

[0100] Unlike Example 3, Comparative Example 16 used 0% dry fine-grained tailings soil as the lime added, but otherwise it was the same as Example 3, and the required materials and data were prepared in the same way.

[0101] Comparative Example 17:

[0102] Unlike Example 3, Comparative Example 17 added 2% of dry fine-grained tailings soil by mass, while the rest was the same as in Example 3, and the required materials and data were prepared in the same manner.

[0103] Comparative Example 18:

[0104] Unlike Example 3, Comparative Example 18 added 4% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 3, and the required materials and data were prepared in the same manner.

[0105] Comparative Example 19:

[0106] Unlike Example 3, Comparative Example 19 added 8% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 3, and the required materials and data were prepared in the same manner.

[0107] Comparative Example 20:

[0108] Unlike Example 3, Comparative Example 20 added 10% of the mass of dry fine-grained tailings soil with lime. The rest was the same as in Example 3, and the required materials and data were prepared in the same manner.

[0109] Comparative Example 21:

[0110] Unlike Example 3, Comparative Example 21 used 12% dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 3. The required materials and data were prepared in the same manner.

[0111] Comparative Example 22:

[0112] Unlike Example 3, Comparative Example 22 added 14% of dry fine-grained tailings soil by mass of lime, while the rest was the same as in Example 3, and the required materials and data were prepared in the same manner.

[0113] Comparative Example 23:

[0114] Unlike Example 3, the soil in Comparative Example 23 was conventional clay with a particle composition similar to fine-grained tailings soil. The added lime was 6% of the dry conventional clay mass. The rest was the same as in Example 3, and the required materials and data were prepared in the same way.

[0115] The saturated swelling rates of Examples 3 and Comparative Examples 16 to 23 were determined according to... Figure 4 As shown in the diagram, when the percentage of the embodiment is less than 5% and less than that of Comparative Example 23, there is no requirement for the permeability coefficient of the commonly used cement-stabilized crushed stone base course.

[0116] Furthermore, when the percentage of the embodiment is less than 5% but higher than that of Comparative Example 23, such as Figure 4 As shown, the permeability coefficient of commonly used cement-stabilized crushed stone base courses should be less than 0.05 m / d, i.e., Example 3.

[0117] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A thinning type cement concrete subbase pavement structure based on fine-particle tailings soil, characterized by: The roadbed pavement structure comprises a cement concrete surface layer (1), a cement stabilized macadam base layer (2), a thinning lime stabilized fine particle tailing soil bottom base layer (3), a thinning lime stabilized fine particle tailing soil upper roadbed (4), and a thinning lime stabilized fine particle tailing soil lower roadbed (5). The roadbed pavement structure is sequentially laid from bottom to top with the thinning lime stabilized fine particle tailing soil lower roadbed (5), the thinning lime stabilized fine particle tailing soil upper roadbed (4), the thinning lime stabilized fine particle tailing soil bottom base layer (3), the cement stabilized macadam base layer (2), and the cement concrete surface layer (1).

2. The reduced-thickness cement concrete pavement structure based on fine-particle tailings soil according to claim 1, characterized in that: The thickness of the thinning lime stabilized fine particle tailing soil bottom base layer (3) is 8-15 cm. The thickness of the thinning lime stabilized fine particle tailing soil upper roadbed (4) is 20 cm. The thickness of the thinning lime stabilized fine particle tailing soil lower roadbed (5) is 40-80 cm.

3. The reduced-thickness cement concrete pavement structure based on fine tailings soil according to claim 1, characterized in that: The 7-day unconfined compressive strength of the thinning lime stabilized fine particle tailing soil bottom base layer (3) is not less than 2 MPa.

4. The reduced-thickness cement concrete pavement structure based on fine-particle tailings soil according to claim 1, characterized in that: The California bearing ratio of the thinning lime stabilized fine particle tailing soil upper roadbed (4) and the thinning lime stabilized fine particle tailing soil lower roadbed (5) is not less than 20%.

5. The reduced-thickness cement concrete pavement structure based on fine-particle tailings soil according to claim 1, characterized in that: The maximum particle size of the fine particle tailing soil in the thinning lime stabilized fine particle tailing soil bottom base layer (3), the thinning lime stabilized fine particle tailing soil upper roadbed (4), and the thinning lime stabilized fine particle tailing soil lower roadbed (5) is not more than 4.75 mm; the mass fraction of particles with a particle size of less than 0.075 mm in the fine particle tailing soil is more than 60%, the plasticity index is 17-19, and the organic matter content is less than 5%.

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