Half-excavation and half-filling structure of high-fill roadbed

Abstract

The utility model relates to the technical field of roadbed construction, and discloses a high fill roadbed half-excavation and half-filling structure which comprises a mountain body, an excavation area, a fill area, a side slope and a drainage system, steps are excavated on one side of the mountain body to form the step-shaped excavation area, the fill area is arranged on the other side of the excavation area, and the drainage system is arranged on the side slope. The filling area comprises an embankment layer, a roadbed layer and a pavement layer which are sequentially laid from bottom to top, the advantages of a filling subgrade and an excavation subgrade are combined, and the structure that steps are designed, anchor rods are arranged between the filling area and the excavation subgrade, and a drainage system composed of multiple layers of geogrids, drainage ditches and drainage pipes is arranged in a matched mode is adopted. The roadbed can adapt to various complex terrain conditions, the bearing capacity and stability of the roadbed are enhanced, and subsidence and deformation of the roadbed in the natural environment and under the action of traffic loads are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to roadbed construction technical field, concretely is high fill roadbed half -excavation half -filling structure. BACKGROUND

[0002] High fill roadbed mainly refers to under specific topographic conditions, such as rice field or perennial waterlogged zone, the height embankment height filled with fine particle soil is above 6m, and the height embankment filled with soil or stone is above 20m in other zones, the existing high fill roadbed is when meeting mountain, if adopting the structure of separate excavation, due to the filling height being higher, the overall stability, strength and stiffness are insufficient, and landslide is easy to occur, if adopting the structure of separate filling, due to the filling height being higher, a large amount of filling material is needed, and stratified filling and embankment compaction are needed, leading to the problem of large cumulative settlement, and the drainage of one side of mountain is not smooth, leading to the problem of roadbed collapse. SUMMARY

[0003] The utility model discloses high fill roadbed half -excavation half -filling structure to solve the problem of the overall stability, strength and stiffness of the existing high fill roadbed adopting the structure of separate excavation being insufficient and landslide being easy to occur, the cumulative settlement being large and the drainage of one side of mountain being not smooth, leading to the problem of roadbed collapse in the background art.

[0004] To achieve the above object, the utility model provides the following technical scheme:

[0005] High fill roadbed half -excavation half -filling structure, including mountain, excavation area, filling area, side slope and drainage system, the both sides of roadbed are side slope, and the side slope is multistage side slope, the mountain one side is excavated step and forms the ladder shape excavation area, and the step width of excavation area is greater than 2m and the gradient is 4%~5% inward, the other side of excavation area is equipped with filling area, and the filling area includes embankment layer, roadbed layer and pavement layer sequentially laid from bottom to top, the embankment layer is filled with filler and sets up one layer of geogrid every 4~6m, and the embankment layer is equipped with stone layer and soil layer from bottom to top, the soil layer is laid with soil material, and the stone layer sequentially includes lower stone layer and upper stone layer from bottom to top, and the lower stone layer is laid with the stone of 30cm~40cm particle size, and the upper stone layer is laid with the stone of 20cm~30cm particle size.

[0006] Further, the loose laying thickness of embankment layer is as follows: the loose laying thickness of soil material is not more than 30cm, the loose laying thickness of lower stone layer is not more than 50cm, and the loose laying thickness of upper stone layer is not more than 40cm.

[0007] Further, the maximum block diameter of the stone filled in lower stone layer and upper stone layer is less than

[0008] Further, the roadbed layer is filled with coarse-grained gravel soil with a thickness of 0.8-1.2 m, and a layer of geogrid is arranged at each of positions 0.4 m and 0.8 m below the top of the roadbed layer.

[0009] Further, the geogrid is a polypropylene three-way geogrid fixed by U-shaped steel nails.

[0010] Further, the slope is a three-stage slope comprising a first-stage slope, a second-stage slope and a third-stage slope from bottom to top, and a platform is arranged between each of the slopes, the slope ratio of the first-stage slope is 1:20, the slope ratio of the second-stage slope is 1:1.75, and the slope ratio of the third-stage slope is 1:1.50.

[0011] Further, an anchor rod is arranged in the step of the excavation area, one end of the anchor rod is fixed in the step of the excavation area, and the other end is inserted into and fixed in the filling area.

[0012] Further, the pavement layer is asphalt concrete with a thickness of 12-18 cm.

[0013] Further, the drainage system comprises a drainage ditch and a drainage pipe, the drainage ditch is arranged at the bottom of the slope, the drainage pipe is arranged in the excavation area at the bottom of the mountain, and the drainage pipe is divided into a plurality of transverse pipes in the excavation area and passes through the filling area to the other side slope of the roadbed.

[0014] Compared with the prior art, the utility model has the advantages that:

[0015] 1. The cross section of the semi-filling and semi-excavation type roadbed is partly excavated to reduce the height of the terrain, and partly filled to increase the height of the terrain or supplement the width of the roadbed; the step arranged at the junction of the filling area and the excavation area is excavated and filled and compacted layer by layer to increase the resistance of the sliding surface and prevent the roadbed from cracking, sliding or collapsing; the anchor rod arranged between the filling area and the excavation area further enhances the overall stability and reduces the risk of cracking, sliding or collapsing of the roadbed.

[0016] 2. A layer of geogrid is arranged every 4-6 m when filling the filler in the embankment layer, the geogrid and the filler together form a composite structure, the load is dispersed to reduce the differential settlement of the roadbed, the settlement of the embankment layer is more uniform, and the problem of road surface cracking caused by uneven settlement is avoided; a layer of geogrid is arranged at each of positions 0.4 m and 0.8 m below the top of the roadbed layer, when the geogrid is subjected to concentrated stress, the high elastic modulus characteristics of the geogrid will generate a vertical component force after being stressed, which disperses and offsets part of the load, effectively enhancing the overall bearing capacity.

[0017] 3、Two side slopes gradually transition from a first stage slope with a relatively gentle slope of 1:20 to a third stage slope with a relatively steep slope of 1:1.50 by gradually adjusting the slope ratio, reducing the risk of landslides or collapses of the side slopes due to excessively large slope ratios, and improving the overall safety of the side slopes; meanwhile, the platforms between each stage of side slopes can serve as natural drainage channels to guide rainwater and other moisture to quickly drain out of the side slope area, reducing the accumulation of moisture in the side slopes and the problem of side slope instability caused by excessive moisture, further enhancing the stability of the road;

[0018] 4、A drainage ditch is arranged at the bottom of the side slope, a drainage pipe is arranged in the excavation area at the bottom of the mountain, and the drainage pipe is divided into multiple transverse pipes in the excavation area and penetrates through the fill area to the other side slope of the roadbed, so that part of the water is introduced into the other side slope through the drainage pipe for drainage, ensuring the safety of the roadbed.

[0019] In summary, the semi-fill semi-excavation structure combines the advantages of fill roadbeds and excavation roadbeds, and through the mutual cooperation of the structures of the steps, the anchor rods arranged between the fill area and the excavation area, the multiple layers of geogrids, the gradual adjustment of the slope ratios of the two side slopes, and the drainage system composed of the drainage ditch and the drainage pipe, the structure can adapt to various complex terrain conditions, enhance the bearing capacity and stability of the roadbed, and reduce the settlement and deformation of the roadbed under the action of natural environment and driving load. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a cross section schematic view of the high fill roadbed semi-excavation semi-fill structure of the utility model;

[0021] Figure 2 It is a partial cross section schematic view of the high fill roadbed semi-excavation semi-fill structure of the utility model;

[0022] In the figure: 100-mountain, 200-excavation area, 210-anchor rod, 300-fill area, 310-embankment layer, 311-stone layer, 3111-lower stone layer, 3112-upper stone layer, 312-soil layer, 320-roadbed layer, 330-pavement layer, 340-geogrid, 400-side slope, 410-first stage slope, 420-second stage slope, 430-third stage slope, 500-drainage system, 510-drainage ditch, 520-drainage pipe. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0024] For example,Figures 1-2 The high embankment subgrade semi-excavation semi-filling structure is shown, and is characterized in that: it comprises a mountain 100, an excavation area 200, an embankment area 300, a slope 400 and a drainage system 500, the two sides of the subgrade are the slopes 400, the slopes 400 are multi-stage slopes 400; the mountain 100 is excavated on one side to form a stepped excavation area 200, the step width of the excavation area 200 is greater than 2 m and the slope is 4% to 5% inward; the other side of the excavation area 200 is provided with the embankment area 300, the embankment area 300 comprises embankment layers 310, roadbed layers 320 and pavement layers 330 which are sequentially laid from bottom to top, the embankment layers 310 are filled with fillers and a layer of geogrid 340 is arranged every 4 to 6 m of filling, the embankment layers 310 are respectively provided with a stone layer 311 and a soil layer 312 from bottom to top, the soil layer 312 is laid with soil material, and the maximum loose laying thickness of the soil material is not more than 30 cm; the stone layer 311 sequentially comprises a lower stone layer 3111 and an upper stone layer 3112 from bottom to top, the lower stone layer 3111 is laid with stone material with a particle size of 30 cm to 40 cm, and the loose laying thickness thereof is not more than 50 cm; the upper stone layer 3112 is laid with stone material with a particle size of 20 cm to 30 cm, and the loose laying thickness thereof is not more than 40 cm, and the stone layer 311 and the soil layer 312 are respectively filled and compacted in layers according to the filling requirements of the soil embankment and the stone embankment by using a machine.

[0025] In actual construction, the maximum block diameter of the stone material filled in the lower stone layer 3111 and the upper stone layer 3112 is less than 1 / 3 of the layer thickness of the embankment. All gaps are filled with small stones or stone chips, when the stone content exceeds 70%, large stones should be laid first with the large surface downward, then small stones and stone chips are laid to level, and then rolling is performed.

[0026] In actual construction, the treatment mode of the embankment layer 310 includes two forms of impact rolling and dynamic compaction, the dynamic compaction is performed first to compact the deep soil and improve the overall bearing capacity of the foundation, and then the impact rolling is performed to reinforce the surface soil, further improve the stability and compactness of the embankment, and the route pile is restored every 60 cm to 80 cm of filling height to measure the subgrade elevation and width.

[0027] In actual construction, the impact rolling is performed by using a double-wheel triangular self-propelled impact roller in a way that the wheel surfaces are staggered and the wheel traces are not overlapped, the impact rolling is performed 20 to 22 times in the roadbed range and 10 to 12 times in the embankment range, the settlement after the last impact rolling is not greater than 30 mm, the impact direction is changed after 5 times of impact rolling, and the filling leveling and pressure consolidation are performed after the completion of the rolling of each layer.

[0028] In actual construction, the impact speed of the impact roller is 8-15 km / h, and the speed is not more than 8 km / h when turning or approaching a trench or a structure.

[0029] In actual construction, the dynamic compaction construction includes a quincunx-shaped arrangement of ramming points with a spacing of 5 m x 5 m, a ramming energy of 2000-4000 kN, 3-5 ramming passes, and a ramming settlement of each ramming point, wherein when the single-ramming energy is less than 2000 kN, the average settlement of the last two ramming passes is not more than 50 mm; when the single-ramming energy is 2000-4000 kN, the average settlement of the last two ramming passes is not more than 100 mm, and the ramming settlement of the last ramming pass is less than that of the previous ramming pass.

[0030] In actual construction, the roadbed layer 320 is filled with coarse-grained gravel soil with a thickness of 0.8-1.2 m, and a geogrid 340 is arranged at a position 0.4 m and 0.8 m below the top of the roadbed layer 320 to ensure long-term stability of the pavement structure and reduce roadbed settlement cracking.

[0031] In actual construction, the geogrid 340 is a polypropylene three-way geogrid 340 fixed by U-shaped steel nails.

[0032] As shown in Figure 1 The slope 400 is a three-stage slope 400 including a first-stage slope 410, a second-stage slope 420, and a third-stage slope 430 from bottom to top, and a platform is arranged between each stage of the slope 400. The slope ratio of the first-stage slope 410 is 1:20, the slope ratio of the second-stage slope 420 is 1:1.75, and the slope ratio of the third-stage slope 430 is 1:1.50.

[0033] In actual construction, an arch-shaped framework is arranged on the slope 400, and a mixture of plant seeds, fertilizers, water-retaining materials, soil conditioners, etc. is sprayed onto the surface of the slope 400 through spray seeding technology inside and around the arch-shaped framework to restore vegetation on the slope 400 and achieve the purpose of slope protection.

[0034] In actual construction, an anchor rod 210 is arranged in the step of the excavation area 200, one end of the anchor rod 210 is fixed in the step of the excavation area 200, and the other end is inserted into and fixed in the filling area 300.

[0035] In actual construction, the pavement layer 330 is asphalt concrete with a thickness of 12-18 cm.

[0036] As shown in Figure 1As shown, the drainage system 500 comprises a drainage ditch 510 and a drainage pipe 520, the drainage ditch 510 is arranged at the bottom of the slope 400, the water of the roadbed and the slope 400 near the mountain 100 side flows to the side drainage ditch 510, when the drainage capacity is large, only the drainage ditch 510 is easy to appear the poor drainage, therefore, the drainage pipe 520 is arranged in the excavation area 200 at the bottom of the mountain 100, and the drainage pipe 520 is divided into a plurality of transverse pipes in the excavation area 200 and passes through the filling area 300 to the other side slope 400 of the roadbed, part of the water is introduced into the other side slope 400 through the drainage pipe 520 to drain, and the safety of the roadbed is ensured.

[0037] Although the embodiments of the present application have been shown and described, it should be understood by those ordinary skilled in the art that various changes, modifications, replacements and modifications can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high embankment subgrade semi-cut semi-fill structure, characterized in that: The roadbed comprises a mountain, a digging area, a filling area, a slope and a drainage system, the two sides of the roadbed are slopes, and the slopes are multi-stage slopes; a step is dug on one side of the mountain to form a stepped digging area, the width of the step of the digging area is greater than 2 m, and the slope is 4%-5% inward; the other side of the digging area is provided with the filling area, the filling area comprises an embankment layer, a roadbed layer and a pavement layer which are sequentially laid from bottom to top, the embankment layer is filled with fillers, and a layer of geogrid is arranged every 4-6 m, the embankment layer is provided with a stone layer and a soil layer from bottom to top, the soil layer is laid with soil, and the stone layer comprises a lower stone layer and an upper stone layer from bottom to top, the lower stone layer is laid with stone with a particle size of 30-40 cm, and the upper stone layer is laid with stone with a particle size of 20-30 cm.

2. The high fill sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: The loose laying thickness of the embankment layer is that the loose laying thickness of the soil is not more than 30 cm, the loose laying thickness of the lower stone layer is not more than 50 cm, and the loose laying thickness of the upper stone layer is not more than 40 cm.

3. The high fill sub-grade semi-cut and semi-fill structure according to claim 2, characterized in that: The maximum block diameter of the stone in the lower stone layer and the upper stone layer is less than the thickness of the embankment layer 4. The high embankment sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: The roadbed layer is filled with coarse-grained gravel soil, and the thickness is 0.8-1.2 m, and a layer of geogrid is arranged at each of positions 0.4 m and 0.8 m below the top of the roadbed layer.

5. The high fill sub-grade semi-cut and semi-fill structure according to claim 4, characterized in that: The geogrid is a polypropylene three-way geogrid and is fixed by U-shaped steel nails.

6. The high embankment sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: The slope is a three-stage slope and comprises a first-stage slope, a second-stage slope and a third-stage slope from bottom to top, a platform is arranged between each of the slopes, the slope ratio of the first-stage slope is 1:20, the slope ratio of the second-stage slope is 1:1.75, and the slope ratio of the third-stage slope is 1:1.

50. An anchor rod is arranged in the step of the digging area, one end of the anchor rod is fixed in the step of the digging area, and the other end is inserted into and fixed in the filling area.

7. The high embankment sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: The pavement layer is asphalt concrete, and the thickness is 12-18 cm.

8. The high embankment sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: The drainage system comprises a drainage ditch and a drainage pipe, the drainage ditch is arranged at the bottom of the slope, the drainage pipe is arranged in the digging area at the bottom of the mountain, the drainage pipe is divided into a plurality of transverse pipes in the digging area and passes through the filling area to the other side slope of the roadbed.

9. The high embankment sub-grade semi-cut and semi-fill structure according to claim 1, characterized in that: ​

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