A construction method for high and steep slope reinforced embankment

Abstract

The present invention relates to the technical field of embankment construction, and in particular to a method for constructing a high and steep slope reinforced embankment, wherein a certain thickness of permeable filler is filled on the top of the roadbed to form a permeable cushion layer, and at least one first geocell layer formed by filling PET high-strength geocells with permeable filler is arranged on the permeable cushion layer; a gravel protective layer is applied on the top of the first geocell layer, and the gravel protective layer is rolled and leveled; multiple layers of reverse geogrid layers are applied layer by layer on the gravel protective layer, and the reverse geogrid layer of the lower layer is fixedly connected with the reverse geogrid layer of the upper layer; after the construction of each reverse geogrid layer is completed, a buffer filler layer is applied on the top thereof, and a pavement structure layer is applied on the top thereof after the buffer filler layer is compacted and leveled. The advantages of the present invention are: it can realize the reinforcement construction of embankments with a slope of 1:0.75-1:1 and a slope slower than 1:1, and the formed reinforced embankment structure has better stability and is also suitable for the arrangement of greening.

Description

Technical Field

[0001] The invention relates to the technical field of embankment construction, in particular to a construction method of a high and steep slope reinforced embankment. Background Art

[0002] In the process of building mountain roads, when the ground cross slope is steep, or in urban roads that are restricted by terrain, landforms or land occupation, the conventional large slope foot design cannot be used. In order to ensure the stability of the roadbed slope, masonry structure is usually used to shrink the slope foot. The use of geogrid reinforced steep slope embankment can replace the masonry structure, significantly reducing the construction difficulty of the project, shortening the construction period, reducing project costs and accelerating project progress.

[0003] However, during construction at home and abroad, geogrid-reinforced embankment structures are not suitable for high and steep slopes with a slope ratio of 1:0.75-1:1. Geogrid reinforcement alone cannot meet the slope protection requirements of high and steep slopes, and the permeability and stability of the bottom of the geogrid-reinforced embankment structure are poor. Summary of the invention

[0004] The purpose of the present invention is to provide a construction method for a high and steep slope reinforced embankment based on the above-mentioned deficiencies of the prior art, so as to solve the problem that the existing geogrid reinforced embankment structure is not suitable for high and steep slopes with a slope ratio of 1:0.75-1:1 and the permeability and stability of its bottom are poor.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] A construction method for a high and steep slope reinforced embankment, characterized in that the construction method comprises the following steps:

[0007] Step S1: roadbed treatment, site cleaning, removal of sliding bodies within the roadbed range and leveling of the site;

[0008] Step S2, filling a certain thickness of permeable filler above the roadbed to form a permeable cushion layer, and arranging at least one first geocell layer formed by filling PET high-strength geocells with permeable filler on the permeable cushion layer;

[0009] Step S3, applying a gravel protective layer on the first geocell layer, and rolling the gravel protective layer flat;

[0010] Step S4, applying a first layer of reverse geogrid layer on the gravel protective layer, erecting a temporary formwork and pulling a wire according to the slope inclination of the reinforced earth embankment, and then laying the first geogrid of the first layer of reverse geogrid layer, wherein both ends of the first geogrid are reverse sections, and the reverse sections are temporarily arranged outside the reinforced embankment;

[0011] Step S5, when the slope angle corresponding to the slope of one side of the reinforced embankment is 1:0.75-1:1, grid filler is spread on the first geogrid layer and compacted to the top surface elevation of the first inverted geogrid layer, and then the inverted section of the first geogrid is inverted upward to the top surface of the compacted filler to form a first inverted geogrid layer;

[0012] Step S6, constructing a second and subsequent geogrid layers on the first geogrid layer along the temporary formwork, layer by layer until the designed number of layers is reached, and at the same time, the lower geogrid layer is fixedly connected to the upper geogrid layer;

[0013] Step S7: After the construction of each of the reverse geogrid layers is completed, a buffer filler layer is applied on the top thereof, and after the buffer filler layer is compacted and leveled, a pavement structure layer is applied on top thereof.

[0014] In step S5, when the slope of the other side of the reinforced earth embankment is 1:0.75-1:1, a second geocell layer is constructed from bottom to top on the slope according to the slope, and each of the second geocell layers is formed by filling PET high-strength geocells with planting soil, and each of the second geocell layers is fixed to the roadbed body by anchors.

[0015] In step S5, when the slope of the other side of the reinforced earth embankment is gentler than 1:1, the first geogrid is constructed in layers in sequence, and a row of vegetation bags is arranged longitudinally near the slope of each layer and filled with stuffing, and the upper and lower layers of vegetation bags are staggered up and down; a second geogrid is applied between the two rows of vegetation bags, and one end of the second geogrid is fixed between the upper and lower layers of vegetation bags, and the other end extends laterally along the main body of the roadbed.

[0016] The second geogrid and the first geogrid are fixed with U-shaped nails. After the filler is spread and compacted to the top surface elevation of the first geogrid layer, the reverse section of the first geogrid is reversed upward along the slope to the top surface of the compacted filler to form the first geogrid layer.

[0017] A three-dimensional geonet is applied on the side slope surface, and the three-dimensional geonet is fixed by anchor rods, and the anchor rods penetrate into the anti-soil grid layer of the roadbed body.

[0018] The same permeable filler is used to fill the permeable cushion layer and the PET high-strength geocell of the first geocell layer, and the permeable fillers of the two are interlocked.

[0019] The advantages of the present invention are:

[0020] 1) By setting a permeable cushion layer on the roadbed and a geocell layer formed by filling PET high-strength geocells with permeable fillers, the permeable cushion layer can provide a foundation for the geocells and improve the permeability of the bottom of the embankment. Compared with ordinary cells, PET high-strength geocells have the characteristics of high tensile strength, lower elongation and higher cell stiffness. In combination with permeable fillers, it has higher effectiveness and safety in the treatment of poor geology, can better reinforce various poor foundations, stabilize the soil, achieve higher matrix bearing capacity, prevent uneven settlement, and have obvious effects;

[0021] 2) Multiple geocell layers stacked and fixed on the steep slope surface, with the support of PET high-strength geocells and further fixed by anchor rods, can make the embankment on the steep slope surface obtain higher strength slope protection, better stability, and also enable plant planting;

[0022] 3) For steep slopes with a slope ratio of less than 1:1, the reinforcement structure of the main grid bars and auxiliary grid bars formed by the reverse geogrid layer can improve the integrity and firmness of the formed roadbed, and at the same time, the vegetation bags can be better fixed. With the cooperation of the three-dimensional geonet, the plants grown by the sprayed grass can grow better, and the stability of the roadbed slope can be improved;

[0023] 4) The anchors used are adjustable to strengthen the anchoring function. The storks that can be retracted or extended outward can facilitate the anchoring and anchoring of the anchors, which is more convenient to use and improves the anchoring effect. The anchors with storks can also strengthen the connection between the second geocell layer and the reverse geogrid layer, so that the second geocell layer can be well fixed.

[0024] 5) It is possible to realize the reinforcement construction of embankments with a slope of 1:0.75-1:1 and a slope gentler than 1:1, and the formed reinforced embankment structure has better stability and is also suitable for the arrangement of greening; at the same time, the high and steep slope embankment structure constructed by the construction method of the present invention also has a lower cost advantage than other traditional and complex high and steep slope embankments, which can reduce construction costs and has a better stabilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the present invention with a high and steep slope on one side;

[0026] Figure 2 for Figure 1 A local enlarged schematic diagram in FIG.

[0027] Figure 3 This is a schematic diagram of the structure of the present invention with a low steep slope on one side;

[0028] Figure 4 It is a schematic diagram of the structure of the U-shaped nail in the present invention;

[0029] Figure 5 is a cross-sectional schematic diagram of the anchoring member in the present invention;

[0030] Figure 6 for Figure 5 A local enlarged schematic diagram in FIG.

[0031] Figure 7 It is a front view of the anchoring member in the present invention. DETAILED DESCRIPTION

[0032] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art:

[0033] like Figure 1-7 As shown, the marks in the figure respectively represent: roadbed 1, permeable cushion layer 2, first geocell layer 3, geogrid layer 4, main grid reinforcement 41, auxiliary grid reinforcement 42, connecting rod 43, grid filler 44, buffer filler layer 5, pavement structure layer 6, second geocell layer 7, anchor rod 8, vegetation bag 9, three-dimensional geonet 10, nail body 11, hook 12, anchor 13, anchor outer tube 131, adjusting inner shaft 132, nut pad locking piece 133, bearing 134, adjusting head 135, anchor head 136, threaded adjustment sleeve 137, mounting hole 138, barb 139, driving connecting rod 1310.

[0034] Embodiment 1: Combination Figures 1 to 7 As shown, the construction method of the high steep slope reinforced embankment in this embodiment includes the following steps:

[0035] Step S1: Process the roadbed 1, clean up the site, remove the sliding body, and level the site to ensure that the high and steep slope reinforced embankment can have a stable roadbed foundation.

[0036] Step S2: a 30-50 cm permeable cushion layer 2 filled with permeable filler is provided, and at least one first geocell layer 3 formed by PET high-strength geocells filled with permeable filler is provided on the permeable cushion layer 2.

[0037] In this embodiment, the permeable cushion layer 2 can be composed of gravel fillers and has good permeability. While playing a permeable role, it can also serve as the basis for the first geocell layer 3. The permeable fillers filled in the first geocell layer 3 can also make it have the same homogeneity as the cushion layer, which can improve the bite between the two, making the formed base more stable and more permeable. Compared with ordinary cells, PET high-strength geocells have the characteristics of high tensile strength, lower elongation and higher cell stiffness. In combination with permeable fillers, it has higher effectiveness and safety in the treatment of poor geology, can better reinforce various poor foundations, stabilize the soil, achieve higher base bearing capacity, and prevent uneven settlement, with obvious effects.

[0038] Step S3: a gravel protective layer is arranged on the first geocell layer 3, and then the gravel protective layer is rolled and leveled. The gravel protective layer is used to protect the first geocell layer 3 and ensure its water permeability.

[0039] Step S4: Set the first layer of geogrid 4, set up a temporary formwork and pull the wire according to the slope angle of the reinforced earth embankment, and then lay the first layer of the first geogrid. The two ends of the first geogrid are the reverse sections, and the reverse sections are temporarily placed outside the reinforced embankment. The overlap width of adjacent first geogrids is 150mm.

[0040] Step S5: set the second and above geogrid layers 4 along the temporary formwork. When the slope angle corresponding to the slope angle on one side or both sides of the reinforced earth embankment is 1:0.75-1:1, place a grid filler 44 on the first geogrid, spread it and compact it to the elevation of the top surface of the first layer, then return the return section of the first geogrid upward along the slope to the top surface of the compacted filler to form the first geogrid layer 4. Repeat this step for the remaining geogrid layers thereon, and construct them layer by layer to the designed number of layers. The lower geogrid layer 4 is fixedly connected with the upper geogrid layer 4 by connecting rods 43, so that the roadbed body formed by the multiple geogrid layers 4 has better integrity.

[0041] In this step, a second geogrid can be arranged inside the inverted section of each inverted geogrid layer 4, and the second geogrid is fixedly connected to the first geogrid of the first inverted geogrid layer, thereby forming grid auxiliary reinforcement 42 to improve the stability of the slope of the inverted geogrid layer 4.

[0042] In this step, the grid filler 44 is mudstone or silty clay. Before construction, mudstone or silty clay should be subjected to on-site geotechnical tests, requiring the converted internal friction angle φ≥30°, the maximum filler particle size should not be greater than 100 mm, and the content of particles greater than 60 mm should not exceed 30%.

[0043] Step S6: After the geogrid layer 4 is constructed to form the main body of the roadbed, a buffer filler layer 5 is set on the top. After the buffer filler layer 5 is compacted and leveled, a pavement structure layer 6 is set. The multiple geogrid layers 4 and the pavement structure layer 6 constitute the main body of the roadbed.

[0044] Step S7: A second geocell layer 7 is stacked from bottom to top on at least one side of the main body of the roadbed, each second geocell layer 7 is formed by filling PET high-strength geocells with planting soil, and each geocell layer is fixed to the main body of the roadbed by an anchor rod 8 as an anchor. At the same time, multiple geocell layers stacked and fixed on the high and steep slope surface are further fixed by the anchor rod 8 under the support of the PET high-strength geocell, so that the embankment on the high and steep slope surface can obtain a higher strength slope protection, better stability, and can also achieve plant planting.

[0045] Embodiment 2: The difference between this embodiment and embodiment 1 is that: step S5 of embodiment 1 is aimed at a high and steep slope surface with a slope rate of 1:0.75-1:1 on the other side of the high and steep slope surface, but in this embodiment, a slope construction method is provided when the slope rate of the other side of the high and steep slope surface is gentler than 1:1. When facing a slope surface with the above slope rate, step S5 in embodiment 1 can be used to replace step S5 in embodiment 1.

[0046] Specifically, in step S5 of the present embodiment, when the slope of one side of the main body of the roadbed is a slope with a slope angle corresponding to a slope rate slower than 1:1, construction is carried out in layers on the first geogrid in sequence, and a row of vegetation bags 9 is arranged longitudinally at each layer adjacent to the slope and then filled with stuff. The upper and lower layers of vegetation bags 9 are staggered up and down, and a second geogrid with one end fixed between the upper and lower rows of vegetation bags 9 is provided between the two rows of vegetation bags 9. The other end of the second geogrid extends laterally along the main body of the roadbed, and the second geogrid and the first geogrid are fixed by U-shaped nails. After the stuffing is spread and compacted to the elevation of the top surface of the first layer, the returned section of the first layer of geogrid is returned upward along the slope to the top surface of the compacted stuffing to form the first layer of reversed geogrid layer 4, and this step is repeated for the remaining geogrid layers thereon, and construction is carried out layer by layer to the designed number of layers, and the reversed geogrid layer 4 of the lower layer is fixedly connected to the reversed geogrid layer of the upper layer.

[0047] For the steep slope with a gradient slower than 1:1 in this embodiment, the second geocell layer 7 in the first embodiment is not provided due to the gentle slope. Instead, two vegetation bags 9 stacked in an upper and lower staggered manner are further provided on the inner side of the second end of the reverse geogrid layer 4, and reinforced and stabilized by the second geogrid. The second geogrid can also form grid auxiliary reinforcement 42, which can improve the integrity and firmness of the formed roadbed body and also better fix the vegetation bags 9.

[0048] In this embodiment, a three-dimensional geonet 10 for spraying grass is applied on the steep slope. With the cooperation of the three-dimensional geonet 10, the plants grown by spraying grass can grow better, and the slope stability of the roadbed 1 is improved. The three-dimensional geonet 10 is fixed to the roadbed body by inclined anchor rods 8, and the anchor rods 8 are inserted into the reverse geogrid layer.

[0049] In the specific implementation of the above embodiment: the reverse geogrid layer 4 also includes multiple Figure 4 The U-shaped nail shown in the figure comprises a nail body 11 in a U-shaped structure and two hooks 12 fixed on both sides of the arc-shaped end of the nail body 11, the hooks 12 also in a U-shaped structure and in the same direction as the nail body 11; the nail body 11 of the U-shaped nail fixes the main grille reinforcement 41 to the surface of the grille filler 44, and fixes the auxiliary grille reinforcement 42 through the two hooks 12. Through the U-shaped nail, its main body can pass through the main grille reinforcement 41 or insert into the grille filler 44 for fixing, and at the same time, the auxiliary grille reinforcement 42 can be fixed together through its hooks 12, so that the auxiliary grille reinforcement 42 can be tightened when it is laid.

[0050] Specifically, the length of the nail body 11 is greater than or equal to the thickness of the reversed geogrid layer 4. In this way, the U-shaped nail can fix the main grid reinforcement 41 and the auxiliary grid reinforcement 42 in a more matching manner.

[0051] like Figure 5-7 As shown, in addition to the anchor rod 8 that can be used as an anchor, this embodiment also provides an anchor 13 that can be controllably opened and driven into the main body of the roadbed in the soil to achieve a more stable anchor.

[0052] The anchor 13 comprises an anchor rod outer tube 131, an adjusting inner shaft 132 rotatably connected in the anchor rod outer tube 131, and an anchor head 136 and a nut pad locking member 133 respectively arranged at two ends of the anchor rod outer tube 131, the outer side of the adjusting inner shaft 132 is threadedly connected with at least one threaded adjusting sleeve 137 along its axial direction, and the threaded adjusting sleeve 137 is located between the adjusting inner shaft 132 and the anchor rod outer tube 131; the anchor rod outer tube 131 is respectively provided with at least one mounting hole 138 corresponding to a threaded adjusting tube, and a barb 139 is connected in the mounting hole 138 through a first hinge axis, and the barb 139 matches the mounting hole 138; the outer side of the threaded adjusting sleeve 137 is connected with a driving connecting rod 1310 through a second hinge axis, and the driving connecting rod 1310 is connected to one end of the barb 139 adjacent to the first hinge axis through a third hinge axis; the section inner shaft 132 extends out of the anchor rod outer tube 131 and is fixedly connected with an adjusting head 135.

[0053] In this way, the adjusting inner shaft 132 can be rotated by the adjusting head 135, and the adjusting inner circumference is connected to the anchor rod outer tube 131 through the bearing 134. Since the adjusting inner shaft 132 is threadedly connected to the threaded adjusting sleeve 137, and the threaded adjusting sleeve 137 is connected to the barb 139 through a driving connection, when the adjusting inner shaft 132 rotates, the threaded adjusting sleeve 137 can move up and down, thereby making the barb 139 rotate inward or outward. When the barb 139 rotates outward, it can be inserted into the roadbed body to provide a more stable anchoring effect, and when the barb 139 rotates inward, the barb 139 can be stored in the mounting hole 138, which can facilitate the normal installation of the anchor rod 8 without affecting the installation in the anchor hole, which is more practical and convenient, and the anchor 13 with the barb 139 can also strengthen the connectivity between the second geocell layer 7 and the reverse geogrid layer 4 and the foundation base, so that the second geocell layer 7 can be well fixed. It should be noted that the barbs 139 face the nut pad locking member 133, and the driving connecting rod 1310 and the barbs 139 are generally arranged crosswise but not intersecting, but only connected, so that the barbs 139 can rotate. The installation method of the anchor 13 is consistent with the existing installation method of the anchor rod 8.

[0054] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A method for constructing a high and steep slope reinforced embankment, characterized in that: The construction method comprises the following steps: Step S1: roadbed treatment, site cleaning, removal of sliding bodies within the roadbed range and leveling of the site; Step S2, filling a certain thickness of permeable filler above the roadbed to form a permeable cushion layer, and arranging at least one first geocell layer formed by filling PET high-strength geocells with permeable filler on the permeable cushion layer; Step S3, applying a gravel protective layer on the first geocell layer, and rolling the gravel protective layer flat; Step S4, applying a first layer of reverse geogrid layer on the gravel protective layer, erecting a temporary formwork and pulling a wire according to the slope inclination of the reinforced earth embankment, and then laying the first geogrid of the first layer of reverse geogrid layer, wherein both ends of the first geogrid are reverse sections, and the reverse sections are temporarily arranged outside the reinforced embankment; Step S5, when the slope angle corresponding to the slope of one side of the reinforced embankment is 1:0.75-1:1, grid filler is spread on the first geogrid layer and compacted to the top surface elevation of the first inverted geogrid layer, and then the inverted section of the first geogrid is inverted upward to the top surface of the compacted filler to form a first inverted geogrid layer; Step S6, constructing a second and subsequent geogrid layers on the first geogrid layer along the temporary formwork, layer by layer until the designed number of layers is reached, and at the same time, the lower geogrid layer is fixedly connected to the upper geogrid layer; Step S7, after the construction of each of the reverse geogrid layers is completed, a buffer filler layer is applied on the top thereof, and after the buffer filler layer is compacted and leveled, a pavement structure layer is applied on top thereof; In the step S5, when the slope of the other side of the reinforced earth embankment is 1:0.75-1:1, a second geocell layer is applied from bottom to top on the slope of the other side according to the slope, each of the second geocell layers is formed by filling PET high-strength geocells with planting soil, and each of the second geocell layers is fixed to the roadbed body by anchors; In the step S5, when the slope of the other side of the reinforced earth embankment is gentler than 1:1, the first geogrid is constructed in layers in sequence, and a row of vegetation bags is arranged longitudinally near the side slope of each layer and filled with stuffing, and the upper and lower layers of vegetation bags are staggered up and down; a second geogrid is applied between the two rows of vegetation bags, and one end of the second geogrid is fixed between the upper and lower layers of vegetation bags, and the other end extends laterally along the main body of the roadbed; The anchoring member includes an anchor rod outer tube, an adjusting inner shaft rotatably connected in the anchor rod outer tube, and an anchor head and a nut pad locking member respectively arranged at two ends of the anchor rod outer tube, the outer side of the adjusting inner shaft is connected with at least one threaded adjusting sleeve along its axial thread, and the threaded adjusting sleeve is located between the adjusting inner shaft and the anchor rod outer tube; the anchor rod outer tube is respectively provided with at least one mounting hole corresponding to a threaded adjusting tube, and a barb is connected in the mounting hole through a first hinge shaft, and the barb matches the mounting hole; the outer side of the threaded adjusting sleeve is connected with a driving connecting rod through a second hinge shaft, and the driving connecting rod is connected to one end of the barb adjacent to the first hinge shaft through a third hinge shaft; the adjusting inner shaft extends out of the anchor rod outer tube and is fixedly connected with an adjusting head.

2. The method for constructing a high and steep slope reinforced embankment according to claim 1, characterized in that: The second geogrid and the first geogrid are fixed with U-shaped nails. After the filler is spread and compacted to the top surface elevation of the first geogrid layer, the reverse section of the first geogrid is reversed upward along the slope to the top surface of the compacted filler to form the first geogrid layer.

3. The method for constructing a high and steep slope reinforced embankment according to claim 1, characterized in that: A three-dimensional geonet is applied on the side slope surface where the vegetation bags are arranged. The three-dimensional geonet is fixed by anchor rods, and the anchor rods penetrate into the reverse earth grid layer of the roadbed body.

4. The method for constructing a high and steep slope reinforced embankment according to claim 1, characterized in that: The same permeable filler is used to fill the permeable cushion layer and the PET high-strength geocell of the first geocell layer, and the permeable fillers of the two are interlocked.

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