A construction method for soil-rock mixed filling roadbed

Abstract

The present invention provides a construction method for a soil-rock mixed filling roadbed, and relates to the technical field of roadbed construction. The construction method for the soil-rock mixed filling roadbed comprises the following steps: step one, measuring and setting out; step two, cleaning the roadbed; step three, compacting the base; step four, prefabricating fillers; step five, mixing fillers: mixing with large pieces of crushed stone, medium pieces of crushed stone and small pieces of crushed stone respectively, and then mixing the mixture with high liquid limit clay, mixing water and cement, so as to obtain three fillers with different particle sizes; step six, layered filling; step seven, quality inspection: inspecting and reporting the compaction quality of the roadbed after rolling. The construction method uses the waste slag generated by deep excavation of road cuttings and tunnel construction and the non-applicable soil when cleaning the roadbed as raw materials, which can effectively reduce the construction cost of the roadbed, utilize waste, and thus effectively reduce the pressure of raw material transportation and the construction period of the roadbed.

Description

Technical Field

[0001] The invention relates to the technical field of roadbed construction, in particular to a construction method for a soil-rock mixed filling roadbed. Background Art

[0002] With the development of my country's economic construction and the extension of highway and railway network construction, the terrain faced by more and more highway and railway construction has shifted from mainly plain and slightly hilly areas to mainly mountainous and hilly areas. This also determines that the phenomenon of high filling and deep excavation of roadbed will become more common.

[0003] In consideration of economic and environmental benefits, engineering units usually select waste slag generated by deep excavation of road cuttings and tunnel construction as fillers. The advantages of this are that on the one hand, it effectively solves problems such as the expropriation of sites for the storage of excavated waste materials, the occupation of farmland by large amounts of waste, and the destruction of the environment along the line. On the other hand, it also reduces the transportation distance and transportation force of the fillers, reduces construction costs, and shortens the construction period. However, this type of filler has the significant characteristics of soil-rock mixture, high stone content, and large particle size. At present, the formulation of relevant technical standards and specifications for highway and railway subgrades in my country is still mainly based on fine-grained soil fillers, which are not completely applicable to soil-rock mixed material subgrades containing a large amount of boulders. A large number of engineering practices have also shown that not all waste slag from soil-rock mixtures are suitable for use as roadbed filling materials. If it is not limited or selected, and the excavated waste slag is used directly as roadbed filling material for high-fill construction, or filled on steep slopes or poor foundations, it may cause a variety of problems, such as instability of the roadbed and foundation, uneven settlement, and excessive post-construction settlement. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a construction method for a soil-rock mixed filling roadbed, which solves the problem of poor construction effect of the existing waste slag mixed filling roadbed.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A construction method for a soil-rock mixed filling roadbed comprises the following steps:

[0008] Step 1: Survey and set out: Measure and set out the shoulder to be constructed, restore the center line and set out the side line, check the geological conditions and soil conditions of the roadbed, take measures for roadbed drainage, and determine the mixing position of the mixture;

[0009] Step 2: Clean the roadbed: remove the tree roots, grass roots and other plant roots within the roadbed, and clean and dig out the 30cm thick planting soil and non-applicable soil within the roadbed filling base until the foundation soil meets the requirements;

[0010] Step 3: Compact the base: Sprinkle water on the bottom of the cushion within the filling range. After the cushion bottom reaches the optimal moisture content, use a heavy-duty vibratory roller to compact the base.

[0011] Step 4: Prefabricated filler: The waste slag generated by deep excavation of road cuttings and tunnel construction is crushed by a crushing device so that the particle diameter of the waste slag is between 3-5 mm, and the waste slag is mixed with the unsuitable soil when cleaning the roadbed so that the soil content of the mixed waste slag is between 30%-50%;

[0012] Step 5, mixed filler: mix with large crushed stone, medium crushed stone and small crushed stone respectively, and then mix the mixture with high liquid limit clay, mixing water and cement to obtain three fillers with different particle sizes;

[0013] Step 6: Layered filling: Fill the filler in layers on the base, and use a bulldozer and a grader to level and roll it flat;

[0014] Step 7. Quality inspection: Inspect and report the compaction quality of the roadbed after rolling. If it is qualified, the next layer will be filled. If it is unqualified, it will be rolled again by the grader.

[0015] Preferably, the mixing position of the mixture is set on flat ground 1-2 km near the roadbed construction position.

[0016] Preferably, the crushed stone is made of hard rock with a uniaxial compressive strength of ≥15 MPa, the particle size of the large crushed stone is 18-24 mm, the particle size of the medium crushed stone is 12-16 mm, and the particle size of the small crushed stone is 5-12 mm.

[0017] Preferably, the mass ratio of the mixed waste residue, crushed stone, high liquid limit clay, mixing water and cement in the filler is (20-35): (25-30): (80-100): (30-40): (25-35).

[0018] Preferably, the filler needs to be tested for moisture content when it is transported from the mixing and stirring position to the roadbed by a loader: when the moisture content of the filler is lower than the optimum moisture content of the filler, water gate material is added to the filler so that the moisture content of the filler reaches the optimum moisture content; when the moisture content of the filler is higher than the optimum moisture content of the filler, quicklime is added to the filler so that the moisture content of the filler reaches the optimum moisture content.

[0019] Preferably, the loose laying thickness of each packing layer is not less than 50 cm, and the crushed stone particle size of the packing layer increases gradually from bottom to top.

[0020] Preferably, the filler is first leveled by a bulldozer before being loosely laid, and then rolled flat by a grader. The speed of the grader is no more than 4 km / h. Weak vibration rolling is performed 2 to 3 times, and then strong vibration rolling is performed 3 to 6 times.

[0021] Preferably, the roadbed compaction quality detection adopts the settlement difference method.

[0022] (III) Beneficial effects

[0023] The present invention provides a construction method for a soil-rock mixed filling roadbed. It has the following beneficial effects:

[0024] 1. This construction method uses the waste slag generated by deep excavation of road cuttings and tunnel construction and the unsuitable soil when cleaning the roadbed as raw materials, which can effectively reduce the construction cost of the roadbed and utilize waste, thereby effectively reducing the pressure of raw material transportation and the construction period of the roadbed.

[0025] 2. This construction method uses high liquid limit clay as the main raw material, with the addition of crushed stone and cement, which can effectively improve the stability of the roadbed and reduce the gaps between the fillers, thereby effectively improving the compactness of the roadbed and greatly improving the safety, durability and reliability of the roadbed. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example:

[0028] The embodiment of the present invention provides a construction method of a soil-rock mixed filling roadbed, comprising the following steps:

[0029] Step 1: Survey and lay out: survey and lay out the shoulder to be constructed, restore the center line and lay out the side line, check the geological and soil conditions of the roadbed, take measures for roadbed drainage, and determine the mixing position of the mixture. The mixing position of the mixture is set on flat ground 1-2km near the roadbed construction position.

[0030] Step 2: Clean the roadbed: remove the tree roots, grass roots and other plant roots within the roadbed, and clean and dig out the 30cm thick planting soil and non-applicable soil within the roadbed filling base until the foundation soil meets the requirements;

[0031] Step 3: Compact the base: Sprinkle water on the bottom of the cushion within the filling range. After the cushion bottom reaches the optimal moisture content, use a heavy-duty vibratory roller to compact the base.

[0032] Step 4: Prefabricated filler: The waste slag generated by deep excavation of road cuttings and tunnel construction is crushed by a crushing device so that the particle diameter of the waste slag is between 3-5 mm, and the waste slag is mixed with the unsuitable soil when cleaning the roadbed so that the soil content of the mixed waste slag is between 30%-50%;

[0033] Step 5, mixed filler: respectively mix with large crushed stone, medium crushed stone and small crushed stone, and then mix the mixture with high liquid limit clay, mixing water and cement to obtain three fillers with different particle sizes, wherein the crushed stone adopts hard rock with uniaxial compressive strength ≥15MPa, the particle size of the large crushed stone is 18-24mm, the particle size of the medium crushed stone is 12-16mm, and the particle size of the small crushed stone is 5-12mm, and the mass ratio of mixed waste residue, crushed stone, high liquid limit clay, mixing water and cement in the filler is (20-35): (25-30): (80-100): (30-40): (25-35).

[0034] Step six, layered filling: fill the filler in layers on the base, and use a bulldozer and a grader to level and roll it flat. The filler needs to be tested for moisture content when it is transported from the mixing position to the roadbed by a loader: when the moisture content of the filler is lower than the optimum moisture content of the filler, add water gate material to the filler so that the moisture content of the filler reaches the optimum moisture content; when the moisture content of the filler is higher than the optimum moisture content of the filler, add quicklime to the filler so that the moisture content of the filler reaches the optimum moisture content. The loose laying thickness of each layer of the filler is not less than 50 cm, and the crushed stone particle size of the filler layer gradually increases from bottom to top. The filler is first leveled by a bulldozer and then rolled flat by a grader. The speed of the grader is not more than 4 km / h. First, perform weak vibration rolling 2 to 3 times, and then perform strong vibration rolling 3 to 6 times.

[0035] Step 7, quality inspection: the roadbed compaction quality after rolling is inspected and reported for inspection. If qualified, the next layer of filling will be carried out. If unqualified, it will be rolled again by the grader. The roadbed compaction quality inspection adopts the settlement difference method.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for a soil-rock mixed filling roadbed, characterized in that: The following steps are involved: Step 1: Survey and set out: Measure and set out the shoulder to be constructed, restore the center line and set out the side line, check the geological conditions and soil conditions of the roadbed, take measures for roadbed drainage, and determine the mixing position of the mixture; Step 2: Clean the roadbed: remove the tree roots, grass roots and other plant roots within the roadbed, and clean and dig out the 30cm thick planting soil and non-applicable soil within the roadbed filling base until the foundation soil meets the requirements; Step 3: Compact the base: Sprinkle water on the bottom of the cushion layer within the filling range. After the cushion layer reaches the optimum moisture content, use a heavy-duty vibratory roller to compact the base. Step 4: Prefabricated filler: The waste slag generated by deep excavation of road cuttings and tunnel construction is crushed by a crushing device so that the particle diameter of the waste slag is between 3 and 5 mm, and the waste slag is mixed with the unsuitable soil when cleaning the roadbed so that the soil content of the mixed waste slag is between 30% and 50%; Step 5, mixed filler: mix with large crushed stone, medium crushed stone and small crushed stone respectively, and then mix the mixture with high liquid limit clay, mixing water and cement to obtain three fillers with different particle sizes; Step 6: Layered filling: Fill the filler in layers on the base, and use a bulldozer and a grader to level and roll it flat; Step 7: Quality inspection: The compaction quality of the roadbed after rolling is inspected and reported for inspection. If it is qualified, the next layer of filling will be carried out. If it is unqualified, it will be rolled again by the grader; The crushed stone is made of hard rock with a uniaxial compressive strength of ≥15MPa, the particle size of the large crushed stone is 18-24mm, the particle size of the medium crushed stone is 12-16mm, and the particle size of the small crushed stone is 5-12mm; The mass ratio of the mixed waste residue, crushed stone, high liquid limit clay, mixing water and cement in the filler is (20-35): (25-30): (80-100): (30-40): (25-35); The loose thickness of each packing layer is not less than 50 cm, and the crushed stone particle size of the packing layer increases gradually from bottom to top; The filler is first leveled by a bulldozer before being loosely laid, and then rolled flat by a grader. The speed of the grader is no more than 4 km / h. Weak vibration rolling is performed 2 to 3 times, and then strong vibration rolling is performed 3 to 6 times.

2. The construction method of a soil-rock mixed filling roadbed according to claim 1, characterized in that: The mixing position of the mixed material is set on the flat ground 1 to 2 km near the roadbed construction position.

3. The construction method of a soil-rock mixed filling roadbed according to claim 1, characterized in that: The filler needs to be tested for moisture content when it is transported from the mixing and stirring position to the roadbed by a loader: when the moisture content of the filler is lower than the optimum moisture content of the filler, water gate material is added to the filler so that the moisture content of the filler reaches the optimum moisture content; when the moisture content of the filler is higher than the optimum moisture content of the filler, quicklime is added to the filler so that the moisture content of the filler reaches the optimum moisture content.

4. The construction method of a soil-rock mixed filling roadbed according to claim 1, characterized in that: The roadbed compaction quality detection adopts the settlement difference method.