CN219410372U - Steep mountain urban road width-splicing roadbed structure - Google Patents

Abstract

The utility model discloses a steep mountain urban road widening roadbed structure, which belongs to the field of road widening roadbeds and comprises the following components: the step connecting part is arranged on one side of the original roadbed, which is required to be spliced and widened; the foam lightweight soil filling body is in butt joint with the step joint part; the L-shaped panel wall is arranged on one side of the foam lightweight filling body, which is far away from the step connection part, a pull rod hole is formed in the L-shaped panel wall, and the foam lightweight soil filling body is flush with the top of the L-shaped panel wall; the low-roof wall is arranged at the tops of the foam lightweight soil filling body and the L-shaped panel wall; the common soil filling body is arranged between the capping short wall and the original roadbed; the horizontal pull rods are locked on the L-shaped panel wall through nuts.

Description

Steep mountain urban road width-splicing roadbed structure

Technical Field

The utility model relates to the field of road widening roadbeds, in particular to a steep mountain urban road widening roadbed structure.

Background

With the development of economic society and the implementation of country's county-like strategy, the city in the relatively backward mountain area of China is being updated and reformed continuously. In the update and reconstruction of mountain cities, the difficult problem of the subgrade widening of steep terrains is often encountered.

At present, large-scale supporting projects such as pile plate walls or pile foundation joist retaining walls are generally adopted for splicing and widening roadbed, the pile plate walls are retaining structures formed by hanging retaining plates between adjacent anti-slide piles, pile foundation joist retaining walls adopt pile foundations and are provided with joists on the pile foundations, and the retaining walls are arranged on the joists, so that the retaining walls have enough stability and bearing capacity. However, large-scale retaining projects such as pile plate walls or pile foundation joist retaining walls often face the problems of high project implementation difficulty, high project cost and the like.

Disclosure of Invention

The utility model aims to at least solve one of the technical problems in the prior art, and therefore, the utility model provides a steep mountain urban road widening roadbed structure, which can rapidly and conveniently complete road roadbed widening and reduce engineering cost.

According to the embodiment of the utility model, the steep mountain urban road widening roadbed structure comprises: the step connecting part is arranged on one side of the original roadbed, which is required to be spliced and widened; the foam lightweight soil filling body is in butt joint with the step joint part; the L-shaped panel wall is arranged on one side of the foam lightweight filling body, which is far away from the step connection part, a pull rod hole is formed in the L-shaped panel wall, and the foam lightweight soil filling body is flush with the top of the L-shaped panel wall; the low-roof wall is arranged at the tops of the foam lightweight soil filling body and the L-shaped panel wall; the common soil filling body is arranged between the capping short wall and the original roadbed; the horizontal pull rods are locked on the L-shaped panel wall through nuts.

The steep mountain urban road widening roadbed structure provided by the embodiment of the utility model has at least the following beneficial effects: the foam light soil is reasonably applied to the splicing width of the urban road subgrade, the excellent characteristics of light weight, high strength, upright solidification, high fluidity, self compaction and the like of the foam light soil material are fully exerted, the light subgrade scheme is used for replacing the traditional large-scale retaining subgrade such as pile plate retaining wall, pile foundation joist retaining wall and the like, the splicing width construction difficulty and the engineering cost of the steep topography subgrade are greatly reduced, meanwhile, the engineering occupied area can be saved due to the great reduction of the retaining scale, and the land resource is fully utilized.

According to some embodiments of the utility model, the step engagement is a beveled step or a standing step.

According to some embodiments of the utility model, the top surface of the capping short wall is provided with a rail mounting hole in which a sidewalk rail is disposed.

According to some embodiments of the utility model, the L-shaped panel wall is further provided with a drain hole.

According to some embodiments of the utility model, the L-shaped panel wall comprises a heel plate, wherein the heel plate is arranged at the bottom of the L-shaped panel wall, and a plain concrete leveling layer is arranged on the heel plate.

According to some embodiments of the utility model, a transverse groove is formed in the top of the plain concrete leveling layer, sand gravel is filled in the transverse groove, a plastic blind pipe is buried in the bottom of the transverse groove, and the plastic blind pipe is arranged in the drain hole in a penetrating mode.

According to some embodiments of the utility model, the foamed lightweight soil filling body is positioned at the upper part of the plain concrete leveling layer, and two layers of galvanized iron wires are respectively arranged at the bottom, the top and the variable cross section of the foamed lightweight soil filling body.

According to some embodiments of the utility model, the horizontal tie rod is a threaded end rod, one end of the threaded end rod is anchored in the original roadbed through drilling, the other end of the threaded end rod is a threaded end, and the threaded end penetrates through the tie rod hole and is fastened on the L-shaped panel wall through a nut.

According to some embodiments of the utility model, the foamed lightweight soil filler top is provided with a waterproof geotextile or plain concrete water barrier.

According to some embodiments of the utility model, the capping wall is formed by cast-in-situ reinforced concrete, and a plurality of PVC drain pipes are buried at the bottom of the capping wall.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The utility model is further described below with reference to the drawings and examples;

FIG. 1 is a schematic diagram of a construction of a steep mountain urban road widening subgrade in an embodiment of the utility model;

FIG. 2 is a schematic view of a construction of a road widening subgrade structure for a steep mountain urban road according to another embodiment of the present utility model;

FIG. 3 is a schematic view of the temperature sensing and adjusting assembly of FIG. 1;

fig. 4 is a front view of fig. 3.

Reference numerals:

the original roadbed 100; a step engagement portion 110; a bevel step 111; a vertical step 112;

foam lightweight soil filling body 200; plain concrete screed 210; a transverse groove 220; a plastic blind pipe 230; a galvanized wire mesh 240; pit 250

An L-shaped panel wall 300; a heel plate 310; a threaded end bar 320; a nut 321; a drain hole 330;

pressing the short wall 400; a sidewalk rail 410; a PVC drain pipe 420;

a common soil filling body 500; a waterproof geotextile 510; municipal line 520;

a temperature measurement adjustment assembly 600; a first gear 610; hexagonal hole 611; a second gear 620; a motor 630; a temperature sensor 640; and a controller 650.

Detailed Description

Reference will now be made in detail to the present embodiments of the present utility model, examples of which are illustrated in the accompanying drawings, wherein the accompanying drawings are used to supplement the description of the written description so that one can intuitively and intuitively understand each technical feature and overall technical scheme of the present utility model, but not to limit the scope of the present utility model.

In the description of the present utility model, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, a number means one or more, a number means two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

Referring to fig. 1 to 4, the construction method of the steep mountain urban road widening subgrade of the first aspect of the present embodiment includes the steps of: step 1: clearing the surface of the spliced wide side slope of the original roadbed 100 and excavating a step connection part 110;

step 2: installing an L-shaped panel wall 300 at the outermost side of the spliced wide roadbed, and reserving a pull rod hole and a temperature measuring hole on the L-shaped panel wall 300;

step 3: drilling holes in the step joint part 110 of the original roadbed 100, inserting a threaded end rod 320, grouting for anchoring, reserving a pull rod hole by penetrating the threaded end of the threaded end rod 320 through the L-shaped panel wall 300, and fastening the threaded end rod 320 on the L-shaped panel wall 300 by adopting a nut 321;

step 4: pouring foam lightweight soil between the L-shaped panel wall 300 and the original roadbed 100 to form a foam lightweight soil filling body 200;

step 5: the temperature measurement adjusting assembly 600 is arranged on a temperature measurement hole, one end of the temperature measurement adjusting assembly 600 is inserted into the foam lightweight soil filling body 200, and the other end of the temperature measurement adjusting assembly 600 is connected with a nut 321 on a threaded end rod 320;

step 6: implementing a capping short wall 400 on the top of the foam lightweight soil filling body 200 and the L-shaped panel wall 300, and burying a plurality of drainage PVC pipes at the bottom of the capping short wall 400;

step 7: burying municipal pipelines 520, and performing ordinary roadbed filling construction on the original roadbed 100 and the capping short wall 400, wherein the ordinary roadbed is filled to the top surface of the roadbed;

step 8: and (5) performing pavement structure construction, paving a pavement and installing a railing.

By the construction method for the urban road widening roadbed in the steep mountain area, foam light soil is reasonably applied to the urban road roadbed widening, the excellent characteristics of light weight, high strength, upright solidification, high fluidity, self-compaction and the like of foam light soil materials are fully exerted, the traditional large-scale retaining roadbed such as pile board retaining walls and pile foundation joist retaining walls is replaced by a light roadbed scheme, the construction difficulty and the construction cost of the steep topography roadbed widening are greatly reduced, meanwhile, the construction occupied area can be saved due to the reduction of the retaining scale, and the land resources are fully utilized. In addition, the method comprises the following steps. Through the setting of temperature measurement adjusting part 600, the length of screw thread end pole 320 between former road bed 100 and the L profile is adjusted in real time according to foam lightweight soil material temperature to make screw thread end pole 320 can adapt to the volume change of foam lightweight soil material expend with heat and contract with cold, provide appropriate tensioning force all the time, ensure overall structure's reliability.

As shown in fig. 3 and 4, the temperature measurement adjusting assembly 600 includes: the first gear 610, the first gear 610 is provided with a hexagonal hole 611, the hexagonal hole 611 is matched with the nut 321 on the threaded end rod 320, and the first gear 610 is sleeved on the nut 321 through the hexagonal hole 611; a second gear 620, the second gear 620 being meshed with the first gear 610; the motor 630, the motor 630 wears to locate in the temperature measurement hole, the motor 630 is connected with second gear 620 transmission, the motor 630 drives the second gear 620 to rotate, the second gear 620 drives the first gear 610 to rotate, the first gear 610 screws the nut 321 through the hexagonal hole 611; a temperature sensor 640, wherein the temperature sensor 640 is arranged in the foam lightweight soil filling body 200 in a penetrating manner; and a controller 650, wherein the controller 650 is electrically connected to the motor 630 and the temperature sensor 640, respectively.

The temperature sensor 640 detects the temperature of the foamed lightweight soil and feeds back the temperature information of the foamed lightweight soil to the controller 650, the controller 650 controls the motor 630 to drive the first gear 610 to rotate, the first gear 610 rotates to drive the second gear 620 to rotate, the hexagonal hole 611 on the second gear 620 screws the nut 321, the nut 321 rotates along the threaded end rod 320, and the length and the tension of the threaded end rod 320 between the original roadbed 100 and the L-shaped panel wall 300 are changed, so that the foamed lightweight soil filling body 200 is adapted to the volume change caused by the change of the temperature.

Specifically, when the temperature rises, the temperature sensor 640 detects the temperature rise of the foamed lightweight soil, the temperature rise information of the foamed lightweight soil is fed back to the controller 650, the controller 650 controls the motor 630 to drive the first gear 610 to rotate, the first gear 610 rotates to drive the second gear 620 to rotate, the hexagonal hole 611 on the second gear 620 twists the nut 321, the nut 321 moves in a direction away from the L-shaped panel wall 300, and the length of the threaded end rod 320 between the original roadbed 100 and the L-shaped panel wall 300 becomes, so that the volume of the foamed lightweight soil filling body 200 is adapted to be increased due to the temperature rise.

In some embodiments of the present utility model, an anti-corrosion assembly is also provided on threaded end bar 320 for preventing corrosion of threaded end bar 320, the anti-corrosion assembly including a reference electrode, an auxiliary anode, and a potentiostat. The screw-threaded end bar 320 is protected by a cathodic protection method by applying an electric current to prevent the screw-threaded end bar 320 from being corroded, resulting in failure between the L-shaped profile wall 300 and the original roadbed 100. Further improving the structural stability of the foamed lightweight soil packing body 200.

As shown in fig. 1 and 2, if the original roadbed 100 is a rock roadbed, the step connection portion 110 is an inclined step 111, and if the original roadbed 100 is a soil roadbed, the step connection portion 110 is a vertical step 112.

In step 2, the L-shaped panel wall 300 is further reserved with a drain hole 330, the plain concrete leveling layer 210 is implemented on the upper portion of the heel plate 310 of the L-shaped panel wall 300, a plurality of transverse grooves 220 are formed in the top of the plain concrete leveling layer 210, sand gravel is filled in the transverse grooves 220, plastic blind pipes 230 are buried in the bottom, and the plastic blind pipes 230 penetrate to the outer side of the roadbed through the drain hole 330 reserved in the L-shaped panel wall 300.

In the step 4, the foam light soil is cast in a split mode, the thickness of the cast is not more than 1m at one time, and the upper layer is cast after the lower layer is initially set. The foamed lightweight soil packing body 200 is laid with 2 layers of galvanized wire mesh 240 at the top, bottom and variable cross section, respectively, and the pre-pit 250 is reserved to accommodate the municipal pipeline 520.

Specifically, the top of the foamed lightweight soil packing body 200 is provided with a waterproof geotextile 510 or plain concrete water-blocking layer. The capping short wall 400 is formed by cast-in-situ reinforced concrete, and a plurality of PVC drain pipes 420 are buried at the bottom of the capping short wall 400.

The construction method of the steep mountain urban road widening roadbed is described by a specific construction embodiment, and comprises the following steps:

cleaning the surface of the spliced wide side slope of the original roadbed 100 and excavating steps, wherein the height-width ratio of the steps is not more than 1:1;

the outermost side of the spliced wide roadbed is cast-in-situ by reinforced concrete to implement an L-shaped panel wall 300, and a drainage hole 330 and a pull rod hole are reserved on the panel wall surface;

the upper part of the L-shaped panel wall 300 heel plate 310 is provided with a plain concrete leveling layer 210, the transverse width of the top surface of the plain concrete leveling layer 210 is not less than 2m, a plurality of transverse grooves 220 with the distance of 20cm multiplied by 20cm are longitudinally arranged at the top along the road base at intervals of 2m, sand gravel is filled in the grooves, a plastic blind pipe 230 is buried at the bottom, and a drain hole 330 is reserved through the L-shaped panel wall 300 to penetrate to the outer side of the roadbed;

digging slope holes on the original roadbed 100, inserting a horizontal threaded end rod 320, grouting for anchoring, reserving a pull rod hole by penetrating the threaded end through the L-shaped surface wall 300, and fastening by adopting a nut 321 after the anchoring body reaches the design strength;

foam light soil is poured between the panel wall and the original roadbed 100 in a layered manner, the thickness of the pouring is not more than 1m, the pouring is carried out on the upper layer after the initial setting of the lower layer, 2 layers of galvanized iron wire meshes 240 are respectively paved on the top, the bottom and the step surface of the light soil filling body, and municipal pipelines 520 and street tree pool pits 250 are reserved;

the method comprises the steps of implementing water prevention and drainage on the top surface of foam lightweight soil, fully paving a layer of waterproof geotextile 510 on the top surface of the foam lightweight soil, fully paving the waterproof geotextile 510 on the inner walls of a municipal pipeline 520 and a pavement tree pool reserved pit 250, paving a gravel stone cushion layer with the thickness of 20cm on the bottom, burying a plurality of plastic blind pipes 230 along the longitudinal direction of a road at intervals of 2m, and penetrating out of a panel wall;

the foam lightweight soil filling body 200 and the top of the L-shaped panel wall 300 are cast in situ by adopting reinforced concrete to implement a convex-shaped capping short wall 400, and a plurality of drainage PVC pipes are buried at intervals of 2m along the longitudinal direction at the bottom of the capping short wall 400;

burying municipal pipelines 520, and constructing a common roadbed filling body, wherein the common roadbed is filled to the top surface of the roadbed;

pavement structure construction, pavement paving and railing construction, and pavement tree planting.

The steep mountain urban road widening roadbed structure of the second aspect of the embodiment of the utility model comprises: the step connecting part 110 is arranged on one side of the original roadbed 100, which is required to be spliced and widened; a foamed lightweight soil filling body 200, the foamed lightweight soil filling body 200 being butted with the step joint portion 110; the L-shaped panel wall 300, wherein the L-shaped panel wall 300 is arranged on one side of the foam lightweight filling body far away from the step connection part 110, a pull rod hole is formed in the L-shaped panel wall 300, and the foam lightweight soil filling body 200 is flush with the top of the L-shaped panel wall 300; the capping short wall 400, the capping short wall 400 is disposed on top of the foamed lightweight soil packing body 200 and the L-shaped panel wall 300; the common soil filling body 500, the common soil filling body 500 is arranged between the capping short wall 400 and the original roadbed 100; the plurality of horizontal pull rods, one end anchor of horizontal pull rod is in original road bed 100, and the other end of horizontal pull rod wears to establish in the pull rod hole, and horizontal pull rod passes through nut 321 locking on L type panel wall 300.

The steep mountain urban road width splicing roadbed structure of the second aspect of the embodiment is applied, the foam light soil is reasonably applied to urban road roadbed width splicing, the excellent characteristics of light weight, high strength, upright solidification, high fluidity, self compaction and the like of the foam light soil material are fully exerted, the light roadbed scheme is used for replacing the traditional large-scale supporting roadbed such as pile board retaining walls, pile foundation joist retaining walls and the like, the construction difficulty and the engineering cost of steep topography roadbed width splicing are greatly reduced, meanwhile, the engineering occupied area can be saved due to the large-scale reduction of supporting and retaining, and the land resources are fully utilized.

As shown in fig. 1 and 2, the step engagement portion 110 is a slant step 111 or a standing step 112. The top surface of the capping short wall 400 is provided with a rail mounting hole in which a pavement rail 410 is provided.

Specifically, the L-shaped panel wall 300 is further provided with a drain hole 330. The L-shaped panel wall 300 includes a heel plate 310, the heel plate 310 is disposed at the bottom of the L-shaped panel wall 300, and a plain concrete screed 210 is disposed on the heel plate 310. The horizontal groove 220 is formed at the top of the plain concrete leveling layer 210, sand gravel is filled in the horizontal groove 220, the plastic blind pipe 230 is buried at the bottom of the horizontal groove 220, and the plastic blind pipe 230 is penetrated in the drain hole 330.

As shown in fig. 1, the foamed lightweight soil packing body 200 is positioned on the upper portion of the plain concrete screed 210, and two layers of galvanized wire 240 are provided between the foamed lightweight soil packing body 200 and the plain concrete screed 210. The top of the foamed lightweight soil packing body 200 is provided with a waterproof geotextile 510 or plain concrete water-blocking layer. The capping short wall 400 is formed by cast-in-situ reinforced concrete, and a plurality of PVC drain pipes 420 are buried at the bottom of the capping short wall 400.

Specifically, the horizontal tie rod is a threaded end rod 320, one end of the threaded end rod 320 is anchored in the original roadbed 100 through drilling, the other end of the threaded end rod 320 is a threaded end, and the threaded end passes through the tie rod hole and is fastened on the L-shaped panel wall 300 through a nut 321.

The following describes a steep mountain urban split subgrade structure in a specific embodiment:

the outermost side of the structure is an L-shaped panel wall 300, the top surface of the L-shaped panel wall 300 is lower than the pavement design elevation, a plurality of horizontal pull rods are arranged on the vertical plates of the L-shaped panel wall 300 and anchored in the original roadbed structure, a foam lightweight soil filling body 200 is arranged between the L-shaped panel wall 300 and the original roadbed, the top surface of the foam lightweight soil filling body 200 is flush with the top surface of the L-shaped panel wall 300, the top surfaces of the L-shaped panel wall 300 and the foam lightweight soil filling body 200 are provided with a capping dwarf wall 400, the outer side of the capping dwarf wall 400 is aligned with the outer side of the panel wall, a railing installation hole is reserved on the top surface of the capping dwarf wall 400 and flush with the pavement design elevation, a common soil filling body 500 is arranged between the capping dwarf wall 400 and the original roadbed, the top surface of the common soil filling body 500 is the pavement design elevation of a roadbed, and the upper part of the common soil filling body 500 is the municipal road conventional pavement structure.

The top surface design elevation of the spliced wide roadbed sidewalk is H, the L-shaped panel wall 300 is constructed by adopting reinforced concrete in-situ casting, and the top surface design elevation is H1; the original roadbed 100 is an earth roadbed, which is connected with the spliced wide roadbed through manual excavation of vertical steps 112, and the height-width ratio of the vertical steps is not more than 1:1.

The upper part of the L-shaped panel wall 300 heel plate 310 is provided with a plain concrete leveling layer 210, the transverse width of the top surface of the plain concrete leveling layer 210 is not less than 2m, the top of the plain concrete leveling layer 210 is provided with a plurality of transverse grooves 220 with the distance of 20cm multiplied by 20cm along the longitudinal direction of the roadbed at intervals of 2m, sand gravel is filled in the grooves, a plastic blind pipe 230 is buried at the bottom, and a drain hole 330 is reserved on the L-shaped panel wall 300 to penetrate to the outer side of the roadbed. The foamed lightweight soil filling body 200 is positioned at the upper part of the plain concrete leveling layer 210, and 2 layers of galvanized iron wire meshes 240 are respectively arranged at the bottom, the top and the step surface of the foamed lightweight soil filling body 200.

The horizontal pull rod connected with the original roadbed 100 by the panel wall is a threaded end rod 320 with the diameter of 22mm, the inner side of the horizontal pull rod is anchored in the original roadbed 100 through a drilling hole with the diameter of 100mm, the threaded end penetrates through the panel wall to reserve a pull rod hole and is fastened through a nut 321, and the horizontal pull rod is uniformly distributed along the vertical plate of the panel wall according to a rectangle with the interval of 2m multiplied by 2 m; a waterproof geotextile 510 water-proof layer is fully paved on the top of the foam lightweight soil filling body 200, and the inner side of the water-proof layer is lapped with the original roadbed 100 with the width not smaller than 1m; municipal pipelines 520 and pavement tree pits are reserved in the foam lightweight soil filling body 200, waterproof geotextile 510 is fully paved on the inner wall of the pit 250, a 20cm thick gravel stone cushion is paved on the bottom, and plastic blind pipes 230 are buried along the longitudinal direction of a road at intervals of 2m to penetrate out of a panel wall.

The capping short wall 400 is in a convex shape, the height is h=H-H1, the capping short wall is formed by casting reinforced concrete in situ, and a plurality of PVC drain pipes 420 are buried at intervals of 2m along the longitudinal direction at the bottom; the upper part of the foam lightweight soil filling body 200 is implemented according to the requirements of a common roadbed.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.

Claims (10)

1. A wide roadbed structure is pieced together to steep mountain region urban road for piece together wide to original roadbed (100), its characterized in that includes:

the step connecting part (110), the step connecting part (110) is arranged on one side of the original roadbed (100) which needs to be spliced and widened;

a foamed lightweight soil filling body (200), the foamed lightweight soil filling body (200) being in butt joint with the step joint portion (110);

the L-shaped panel wall (300), wherein the L-shaped panel wall (300) is arranged on one side of the foam light filling body, which is far away from the step connecting part (110), the L-shaped panel wall (300) is provided with a pull rod hole, and the foam light soil filling body (200) is flush with the top of the L-shaped panel wall (300);

a capping short wall (400), the capping short wall (400) being disposed on top of the foamed lightweight soil packing body (200) and the L-shaped panel wall (300);

the common soil filling body (500), the common soil filling body (500) is arranged between the capping short wall (400) and the original roadbed (100);

the horizontal tie rods are anchored in the original roadbed (100), the other ends of the horizontal tie rods penetrate through the tie rod holes, and the horizontal tie rods are locked on the L-shaped panel wall (300) through nuts (321).

2. The steep mountain urban road widening subgrade structure according to claim 1, characterized in that said step engagement portion (110) is a slope step (111) or a standing step (112).

3. The steep mountain urban road widening subgrade structure according to claim 1, wherein the top surface of the capping short wall (400) is provided with a rail mounting hole in which a pavement rail (410) is provided.

4. The steep mountain urban road widening subgrade structure according to claim 1, characterized in that a drain hole (330) is also provided in said L-shaped profile wall (300).

5. The steep mountain urban road widening subgrade structure according to claim 4, in which said L-shaped panel wall (300) comprises a heel plate (310), said heel plate (310) is provided at the bottom of said L-shaped panel wall (300), said heel plate (310) is provided with a plain concrete screed (210).

6. The steep mountain urban road widening roadbed structure according to claim 5, wherein a transverse groove (220) is formed in the top of the plain concrete leveling layer (210), sand gravel is filled in the transverse groove (220), a plastic blind pipe (230) is buried in the bottom of the transverse groove (220), and the plastic blind pipe (230) is penetrated in the drain hole (330).

7. The steep mountain urban road widening subgrade structure according to claim 6, characterized in that said foamed lightweight soil filling body (200) is located on top of said plain concrete screed (210), and two layers of galvanized wire (240) are provided at the bottom, top and variable cross section of said foamed lightweight soil filling body (200), respectively.

8. The steep mountain urban road widening subgrade structure according to claim 1, characterized in that the horizontal tie rod is a threaded end rod (320), one end of the threaded end rod (320) is anchored in the original subgrade (100) by drilling, the other end of the threaded end rod (320) is a threaded end, and the threaded end passes through the tie rod hole and is fastened on the L-shaped panel wall (300) by the nut (321).

9. The steep mountain urban road widening subgrade structure according to claim 1, characterized in that the top of the foamed lightweight soil filling body (200) is provided with a waterproof geotextile (510) or plain concrete water barrier.

10. The steep mountain urban road widening subgrade structure according to claim 1, wherein said capping short wall (400) is formed by reinforced concrete cast-in-place, and a plurality of PVC drain pipes (420) are buried in the bottom of said capping short wall (400).