Modified gravelly soil composite roadbed structure and construction method

Abstract

The invention discloses a modified gravelly soil composite roadbed structure which comprises an earthwork standard room, multiple layers of tires are stacked on the two sides of the earthwork standard room from bottom to top in sequence, each layer of tires are wound and limited through edge covering cloth, the multiple layers of tires are stacked in a triangular shape, and the multiple layers of tires are arranged in the earthwork standard room. Roadbed filler is laid between the tires stacked on the two sides of the geocell. The multi-layer tire is specifically divided into a first-layer tire, a second-layer tire, a third-layer tire and a fourth-layer tire. According to the modified gravelly soil roadbed, a proper amount of tire particles are added into the gravelly soil, the stability of the modified gravelly soil roadbed under the freezing and thawing effect can be effectively improved through specific matching and maintenance treatment, and the service life of a road is prolonged. The bearing capacity of the roadbed is further enhanced through stacking of the multiple layers of tires and wrapping of the turn-back type geogrids, so that the roadbed can bear larger loads and is suitable for construction of more types of roads.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a modified gravel-soil composite roadbed structure and a construction method. Background Art

[0002] Gravel soil roadbed is a common road base structure with good drainage performance and high bearing capacity. In road construction, gravel soil roadbed can provide stable support, reduce vibration during vehicle driving, and extend the service life of the roadbed structure. This technology is widely used in the base treatment of rural roads, temporary roads and urban roads. However, gravel soil roadbed is significantly affected by freeze-thaw, which restricts its application in roadbed construction. It is of great significance to optimize the gravel soil roadbed structure and improve the gravel soil filling. Summary of the invention

[0003] The purpose of the present invention is to solve the above-mentioned problems of the background technology and to provide a modified gravel-soil composite roadbed structure and a construction method.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A modified gravel-soil composite roadbed structure comprises a geocell, wherein multiple layers of tires are stacked in sequence from bottom to top on both sides of the geocell, each layer of tires is limited by wrapping cloth, the multiple layers of tires are stacked in a triangular shape, and roadbed fillers are laid between the tires stacked on both sides of the geocell.

[0006] As a further solution of the present invention: the multi-layer tires are specifically layers, divided into a first layer of tires, a second layer of tires, a third layer of tires and a fourth layer of tires, and the two second layer of tires and the two fourth layer of tires on both sides of the geocell are each wrapped with a folded geogrid.

[0007] A method for constructing a modified gravel-soil composite roadbed comprises the following steps:

[0008] S1. Improved gravel soil ratio test: Conduct comparative analysis on improved gravel soil with different tire particle addition amounts, and finally determine the test ratio with the best effect on improving the frost heave effect of the roadbed;

[0009] S2. Construction measurement preparation: Check whether the cross slope, width, slope, compaction degree, etc. of the gravel soil roadbed subgrade meet the standards. Only after they meet the standards can the subsequent construction be carried out; measure and stake out the test section; clean the subgrade, sprinkle water appropriately during cleaning to keep the subgrade moist, and mark two side lines with lime;

[0010] S3, layered filling: first lay a layer of geocells, then lay the first layer of tires, wrap the second layer of tires with return geogrids, then lay the third layer of tires, and wrap the fourth layer of tires with return geogrids, and fill the tire layers on the left and right sides of the roadbed with roadbed fillers;

[0011] S4. Paving and leveling: paving in layers, controlling the thickness of each layer and the size of the filler particles, rough leveling with a large bulldozer and leveling with a medium-sized paver, and finally leveling with a roller;

[0012] S5. Rolling and compaction: First use a 21t vibratory roller to roll and compact for 2 times, then use a 25t vibratory roller to roll for 5 times, and finally use a static roller to roll for 3 times;

[0013] S6. Joint treatment: First, sprinkle cement slurry of corresponding proportion on the joints, then sprinkle fine materials, and finally grout the joints twice, and lay bidirectional steel-plastic grilles on the upper bearing layer;

[0014] S7, quality inspection: inspect the quality of the roadbed after rolling and compaction. If it does not meet the quality standard, repeat step S6; if it meets the standard, proceed to the next process;

[0015] S8. Roadbed maintenance: Sprinkler maintenance is carried out for 8 days, during which the surface is kept moist. A sprinkler truck should be used 3 days before maintenance to prevent the gravel on the gravel soil roadbed from being washed away due to the angle of the sprinkler head, causing local potholes.

[0016] As a further solution of the present invention: in the step S1, gravel soil is taken on site, placed in an oven at a temperature of 70°C and dried for 24 hours, and then crushed by a grinder and sieved through a 1mm sieve for later use; tire particles are added to the sieved gravel soil powder in amounts of 4%, 6%, and 8%, respectively, and stirred to obtain a mixture; water accounting for 12%-18% of the total mass of the mixture is added to the mixture of each addition amount, and the mixture is fully stirred and mixed to obtain improved gravel soil roadbed filler samples with different proportions; the mixture is sealed in a sealed bag, placed for 24 hours, and then placed in a curing box for curing for 22 days, and the curing conditions are a temperature of 16±2°C and a humidity of 96%.

[0017] As a further solution of the present invention: in step S2, during the staking out, a control pile is placed every 15 m on the outer edge of the embankment foot, the pile number is marked on the pile, and the embankment foot line is determined, with a width of 50 cm on each side.

[0018] As a further solution of the present invention: in step S4, the paving thickness of each layer is controlled not to exceed 45 cm, and the maximum particle size of the filler is controlled not to exceed 12 cm.

[0019] As a further solution of the present invention: in step S6, a fully automatic spreader is used to spread water at the joints, and the cement slurry is 1.5:1. The first time of grouting is before paving and flattening, and the second time is before re-rolling with a double steel wheel roller, and a bidirectional steel-plastic grille is laid on the upper supporting layer.

[0020] As a further solution of the present invention: in step S3, the tire layers on the left and right sides of the roadbed are filled with improved gravel soil filler with 8% tire particles added.

[0021] As a further solution of the present invention: in the step S5, during rolling, the vibration frequency of the roller is 30-35 Hz (1800-2100 times / min), and the amplitude is 1.5-2.0 mm.

[0022] As a further solution of the present invention: in the step S7, during the quality inspection, the appearance inspection is first carried out. The appearance should be free of wheel marks, slurry overflow, uniform and dense surface, no obvious segregation, neat edges, and smooth joints. Sections with unqualified compaction and strength should be reworked.

[0023] Beneficial effects of the present invention:

[0024] Improve freeze-thaw resistance: By adding an appropriate amount of tire particles to the gravel soil, and after a specific ratio and maintenance treatment, the modified gravel soil roadbed of the present invention can effectively improve its stability under freeze-thaw action and extend the service life of the road. Enhance bearing capacity: The stacking of multiple layers of tires and the wrapping of the return geogrid further enhance the bearing capacity of the roadbed, enabling it to withstand greater loads and be suitable for more types of road construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 is a schematic structural diagram of a multi-layer tire of the present invention;

[0028] Figure 3 and 4 It is a structural schematic diagram of the edge binding cloth of the present invention.

[0029] In the figure: 1, geocell; 2, first layer of tires; 3, second layer of tires; 4, third layer of tires; 5, fourth layer of tires; 6, first layer of geogrid; 7, second layer of geogrid; 8, edging cloth; 9, roadbed filler. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0031] For example, see Figure 1-4 As shown, the present invention is a modified gravel-soil composite roadbed structure, comprising a geocell 1, wherein multiple layers of tires are stacked in sequence from bottom to top on both sides of the geocell 1, each layer of tires is limited by wrapping cloth 8, and the multiple layers of tires are stacked in a triangular shape, and roadbed fillers 9 are laid between the tires stacked on both sides of the geocell 1.

[0032] For example 2, please refer to Figure 1-4 As shown, the present invention is a modified gravel-soil composite roadbed structure, comprising a geocell 1, wherein multiple layers of tires are stacked in sequence from bottom to top on both sides of the geocell 1, each layer of tires is limited by wrapping cloth 8, and the multiple layers of tires are stacked in a triangular shape, and roadbed fillers 9 are laid between the tires stacked on both sides of the geocell 1.

[0033] The multi-layer tires specifically consist of 4 layers, which are divided into a first layer tire 2, a second layer tire 3, a third layer tire 4 and a fourth layer tire 5. The two second layer tires 2 and the two fourth layer tires 5 on both sides of the geocell 1 are each wrapped with a folded geogrid.

[0034] The dimensions of the waste tires used are: radius 300mm, section width 200mm, the roadbed filler is improved gravel soil with the optimal ratio, the geocell is a bidirectional high-strength geocell with dimensions of 320mm×240mm and a height of 300mm, the edging cloth is a cold-proof non-woven fabric with good thermal insulation performance, and the return geogrid is a 1.5mm thick steel-plastic geogrid; the filling materials of the geocell and geogrid are both improved gravel soil.

[0035] Embodiment 3, the present invention is a method for constructing a modified gravel-soil composite roadbed, comprising the following steps:

[0036] S1. Improved gravel soil ratio test: Conduct comparative analysis on improved gravel soil with different tire particle addition amounts, and finally determine the test ratio with the best effect on improving the frost heave effect of the roadbed;

[0037] Gravel soil is taken locally, placed in an oven at a temperature of 70°C for drying for 24 hours, and then crushed by a crusher and sieved through a 1mm sieve for later use; tire particles are added to the sieved gravel soil powder in amounts of 4%, 6%, and 8%, respectively, and stirred evenly to obtain a mixture; water accounting for 12%-18% of the total mass of the mixture is added to the mixture of each addition amount, and the mixture is fully stirred and mixed evenly to obtain improved gravel soil roadbed filler samples with different proportions; the samples are sealed in a sealed bag, placed for 24 hours, and then placed in a curing box for curing for 22 days, and the curing conditions are a temperature of 16±2°C and a humidity of 96%;

[0038] S2. Construction measurement preparation: Check whether the cross slope, width, slope, compaction degree, etc. of the gravel soil roadbed subgrade meet the standards. Only after they meet the standards can the subsequent construction be carried out; measure and stake out the test section; clean the subgrade, sprinkle water appropriately during cleaning to keep the subgrade moist, and mark two side lines with lime;

[0039] When staking out, a control pile is placed every 15m on the outer edge of the embankment foot, with the pile number marked on it, to determine the embankment foot line, with a width of 50cm on each side;

[0040] S3, layered filling: first lay a layer of geocell 1, then lay the first layer of tires 2, the second layer of tires 3 is wrapped with a return geogrid 6, then lay the third layer of tires 4, the fourth layer of tires 5 is also wrapped with a return geogrid 7, and the tire layers on the left and right sides of the roadbed are filled with roadbed fillers 9;

[0041] The tire layers on the left and right sides of the roadbed are filled with improved gravel soil filler 9 with 8% tire particles added;

[0042] S4. Paving and leveling: paving in layers, controlling the thickness of each layer and the size of the filler particles, rough leveling with a large bulldozer and leveling with a medium-sized paver, and finally leveling with a roller;

[0043] The thickness of each layer should not exceed 45cm, and the maximum particle size of the filler should not exceed 12cm;

[0044] S5. Rolling and compaction: First use a 21t vibratory roller to roll and compact for 2 times, then use a 25t vibratory roller to roll for 5 times, and finally use a static roller to roll for 3 times;

[0045] During rolling, the vibration frequency of the roller is 30-35Hz, 1800-2100 times / min, and the amplitude is 1.5-2.0mm;

[0046] S6. Joint treatment: First, sprinkle cement slurry of corresponding proportion on the joints, then sprinkle fine materials, and finally grout the joints twice, and lay bidirectional steel-plastic grilles on the upper bearing layer;

[0047] The joints are sprinkled with water using a fully automatic spreader, and the cement slurry is 1.5:1. The first grouting is done before paving and flattening, and the second grouting is done before re-rolling with a double-wheel roller. A bidirectional steel-plastic grille is laid on the upper bearing layer.

[0048] S7, quality inspection: inspect the quality of the roadbed after rolling and compaction. If it does not meet the quality standard, repeat step S6; if it meets the standard, proceed to the next process;

[0049] During the quality inspection, the appearance inspection shall be carried out first. The appearance shall be free of wheel marks, slurry overflow, uniform and dense surface, no obvious segregation, neat edges, and smooth joints. Sections with unqualified compaction and strength shall be reworked.

[0050] S8. Roadbed maintenance: Sprinkle water for 8 days, keeping the surface moist during this period.

[0051] Embodiment 4, the present invention is a method for constructing a modified gravel-soil composite roadbed, comprising the following steps:

[0052] S1. Improved gravel soil ratio test: Conduct comparative analysis on improved gravel soil with different tire particle addition amounts, and finally determine the test ratio with the best effect on improving the frost heave effect of the roadbed;

[0053] S2. Construction measurement preparation: Check whether the cross slope, width, slope, compaction degree, etc. of the gravel soil roadbed subgrade meet the standards. Only after they meet the standards can the subsequent construction be carried out; measure and stake out the test section; clean the subgrade, sprinkle water appropriately during cleaning to keep the subgrade moist, and mark two side lines with lime;

[0054] S3, layered filling: first lay a layer of geocell 1, then lay the first layer of tires 2, the second layer of tires 3 is wrapped with a return geogrid 6, then lay the third layer of tires 4, the fourth layer of tires 5 is also wrapped with a return geogrid 7, and the tire layers on the left and right sides of the roadbed are filled with roadbed fillers 9;

[0055] The roadbed is mainly filled by machinery, supplemented by manual labor. Before filling, the farmland humus, weeds, garbage, tree roots, building foundations, etc. within the roadbed should be cleared and transported to the abandoned soil site for orderly centralized stacking for land reclamation and greening. The old foundation pits, tree pits, ditches, etc. of the original buildings are backfilled with sand and gravel or 9% lime soil, and are backfilled in layers below the roadbed according to the requirements of the technical regulations for municipal engineering construction;

[0056] S4. Paving and leveling: paving in layers, controlling the thickness of each layer and the size of the filler particles, rough leveling with a large bulldozer and leveling with a medium-sized paver, and finally leveling with a roller;

[0057] S5. Rolling and compaction: First use a 21t vibratory roller to roll and compact for 2 times, then use a 25t vibratory roller to roll for 5 times, and finally use a static roller to roll for 3 times;

[0058] S6. Joint treatment: First, sprinkle cement slurry of corresponding proportion on the joints, then sprinkle fine materials, and finally grout the joints twice, and lay bidirectional steel-plastic grilles on the upper bearing layer;

[0059] S7, quality inspection: inspect the quality of the roadbed after rolling and compaction. If it does not meet the quality standard, repeat step S6; if it meets the standard, proceed to the next process;

[0060] S8. Roadbed maintenance: Sprinkle water for 8 days, keeping the surface moist during this period.

[0061] In another embodiment, the tire may be a scrap tire.

[0062] In another embodiment, the size of the waste tires used is 300mm in radius and 200mm in cross-sectional width. The roadbed filler is improved gravel soil with the optimal ratio. The geocell is a bidirectional high-strength geocell with a size of 320mm×240mm and a height of 300mm. The edging cloth is a cold-proof non-woven fabric with good thermal insulation performance. The return geogrid is a 1.5mm thick steel-plastic geogrid. The filling materials of the geocell and the geogrid are both improved gravel soil.

[0063] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A modified gravel-soil composite roadbed structure, characterized in that: It comprises a geocell, wherein multiple layers of tires are stacked in sequence from bottom to top on both sides of the geocell, each layer of tires is limited by wrapping cloth, the multiple layers of tires are stacked in a triangular shape, and roadbed fillers are laid between the tires stacked on both sides of the geocell.

2. The modified gravel soil composite roadbed structure according to claim 1, characterized in that: The multi-layer tires are specifically layers, divided into a first layer of tires, a second layer of tires, a third layer of tires and a fourth layer of tires. The two second layer tires and the two fourth layer tires on both sides of the geocell are each wrapped with a folded geogrid.

3. A method for constructing a modified gravel-soil composite roadbed, characterized in that: The steps include: S1. Improved gravel soil ratio test: Conduct comparative analysis on improved gravel soil with different tire particle addition amounts, and finally determine the test ratio with the best effect on improving the frost heave effect of the roadbed; S2. Construction measurement preparation: Check whether the cross slope, width, slope, compaction degree, etc. of the gravel soil roadbed subgrade meet the standards. Only after they meet the standards can the subsequent construction be carried out; measure and stake out the test section; clean the subgrade, sprinkle water appropriately during cleaning to keep the subgrade moist, and mark two side lines with lime; S3, layered filling: first lay a layer of geocells, then lay the first layer of tires, wrap the second layer of tires with return geogrids, then lay the third layer of tires, and wrap the fourth layer of tires with return geogrids, and fill the tire layers on the left and right sides of the roadbed with roadbed fillers; S4. Paving and leveling: paving in layers, controlling the thickness of each layer and the size of the filler particles, rough leveling with a large bulldozer and leveling with a medium-sized paver, and finally leveling with a roller; S5. Rolling and compaction: First use a 21t vibratory roller to roll and compact for 2 times, then use a 25t vibratory roller to roll for 5 times, and finally use a static roller to roll for 3 times; S6. Joint treatment: First, sprinkle cement slurry of corresponding proportion on the joints, then sprinkle fine materials, and finally grout the joints twice, and lay bidirectional steel-plastic grilles on the upper bearing layer; S7, quality inspection: inspect the quality of the roadbed after rolling and compaction. If it does not meet the quality standard, repeat step S6; if it meets the standard, proceed to the next process; S8. Roadbed maintenance: Sprinkle water for 8 days, keeping the surface moist during this period.

4. A modified gravel soil composite roadbed structure and construction method according to claim 3, characterized in that: In the step S1, gravel soil is taken locally, placed in an oven at a temperature of 70° C. and dried for 24 hours, and then crushed by a pulverizer and sieved through a 1 mm sieve for later use; tire particles are added to the sieved gravel soil powder in amounts of 4%, 6%, and 8%, respectively, and stirred to obtain a mixture; water accounting for 12%-18% of the total mass of the mixture is added to the mixture of each addition amount, and the mixture is fully stirred and mixed to obtain improved gravel soil roadbed filler samples with different proportions; the mixture is sealed in a sealed bag, placed for 24 hours, and then placed in a curing box for curing for 22 days, and the curing conditions are a temperature of 16±2° C. and a humidity of 96%.

5. The modified gravel soil composite roadbed structure and construction method according to claim 3 is characterized in that: In step S2, during the staking out, a control pile is placed every 15 m on the outer edge of the embankment foot, with the pile number marked on the pile, and the embankment foot line is determined, with a width of 50 cm on each side.

6. The modified gravel soil composite roadbed structure and construction method according to claim 3 is characterized in that: In step S4, the paving thickness of each layer is controlled not to exceed 45 cm, and the maximum particle size of the filler is controlled not to exceed 12 cm.

7. The modified gravel soil composite roadbed structure and construction method according to claim 3 is characterized in that: In step S6, water is spread at the joints using a fully automatic spreader, and the cement slurry is 1.5:

1. The first pass of grouting is done before paving and flattening, and the second pass is done before re-rolling with a double steel wheel roller. A bidirectional steel-plastic grille is laid on the upper bearing layer.

8. The modified gravel soil composite roadbed structure and construction method according to claim 3 is characterized in that: In step S3, the tire layers on the left and right sides of the roadbed are filled with improved gravel soil filler with 8% tire particles added.

9. The modified gravel soil composite roadbed structure and construction method according to claim 3, characterized in that: In step S5, during rolling, the vibration frequency of the roller is 30-35 Hz (1800-2100 times / min), and the amplitude is 1.5-2.0 mm.

10. The modified gravel soil composite roadbed structure and construction method according to claim 3, characterized in that: In step S7, during the quality inspection, the appearance inspection is first performed. The appearance should be free of wheel marks, slurry overflow, uniform and dense surface, no obvious segregation phenomenon, neat edges, and smooth joint processing; Sections that do not meet the compaction and strength requirements must be reworked.

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