CN114990948B

CN114990948B - Construction method for reinforcing submerged roadbed by reinforcing ribs

Info

Publication number: CN114990948B
Application number: CN202210575874.4A
Authority: CN
Inventors: 杨广庆; 杨荣博; 许忠印; 张孟强; 邱文利; 徐鹏; 何勇海; 蒲昌瑜; 王志杰; 刘伟超; 王贺; 李婷
Original assignee: Hebei Expressway Jingxiong Management Center; Hebei Xiong'an Jingde Expressway Co ltd; Shijiazhuang Tiedao University; Hebei Communications Planning Design and Research Institute Co Ltd
Current assignee: Hebei Expressway Jingxiong Management Center; Hebei Xiong'an Jingde Expressway Co ltd; Shijiazhuang Tiedao University; Hebei Communications Planning Design and Research Institute Co Ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2023-01-24
Anticipated expiration: 2042-05-25
Also published as: CN114990948A

Abstract

The invention discloses a construction method for reinforcing a submerged roadbed by a rib, belongs to the technical field of roadbed reinforcement and slope protection, and solves the problems of slope seepage damage and poor durability of the reinforced submerged roadbed in the prior art. The construction method comprises the following steps: providing a roadbed, and forming a cushion layer on the foundation; forming an embankment, and forming a reinforced layer in the embankment forming process; forming a protective layer on the embankment slope surface, and forming a reinforcing layer on the top surface of the embankment; forming a road bed on the reinforcing layer to obtain a reinforced and reinforced soaking road bed; the cushion layer, the reinforcing layer and the protective layer form an accommodating space for accommodating the embankment, and the inner wall of the accommodating space is provided with the permeable geotextile. The construction method for reinforcing the submerged roadbed by the reinforcements can be used for road construction.

Description

Construction method for reinforcing submerged roadbed by reinforcing ribs

Technical Field

The invention belongs to the technical field of roadbed reinforcement and slope protection, and particularly relates to a construction method for reinforcing a submerged roadbed.

Background

The conventional embankment is easily attacked by water flow to cause deformation, settlement or collapse, and is difficult to use in a submerged road section. The submerged roadbed refers to an embankment of which one side or two sides of an embankment body are subjected to long-term or seasonal submergence, and the submerged roadbed needs to have load capacity and bear impact effects of water level change, water flow and waves.

In the prior art, the construction mode of the submerged roadbed is mostly to adopt an anti-seepage film, a reinforced concrete panel and a gabion paving treatment on the side slope of the embankment, but the treatment mode is only suitable for the anti-seepage treatment of the surface layer, the problem of side slope seepage damage cannot be solved, and the gabion protection also has the problem of poor durability.

In addition, with the acceleration of the urbanization process, the urban construction waste is continuously increased, the stacking of the construction waste not only occupies a large area and can cause the waste of land resources, but also has the problems of subsequent degradation treatment and great influence on the environment.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a reinforced and reinforced submerged roadbed structure and a construction method thereof, which solve at least one of the problems of slope seepage damage, poor durability and large influence of construction waste on the environment of a submerged roadbed in the prior art.

The invention is mainly realized by the following technical scheme:

the invention provides a construction method for reinforcing a submerged roadbed, which comprises the following steps:

providing a roadbed, and forming a cushion layer on the foundation;

forming an embankment, and forming a reinforced layer in the embankment forming process;

forming a protective layer on the embankment slope surface, and forming a reinforcing layer on the top surface of the embankment;

forming a road bed on the reinforcing layer to obtain a reinforced and reinforced water-soaked road bed;

the cushion layer, the reinforcing layer and the protective layer form an accommodating space for accommodating the embankment, and the inner wall of the accommodating space is provided with the permeable geotextile.

Further, forming an embankment, wherein the step of forming a reinforced layer in the embankment forming process comprises the following steps:

and forming the embankment by adopting horizontal layered filling and layered rolling modes until the distance of the embankment is 1.0m above a water level line, and forming a reinforced layer in the embankment forming process to obtain the embankment and the reinforced layer.

Furthermore, the geocell is filled with permeable materials to form a cushion layer, a reinforcing layer, a protective layer and a reinforcing layer respectively.

Further, the reinforced and reinforced water-immersed roadbed also comprises a concrete foundation arranged on the slope toe of the embankment, and the construction method comprises the following steps:

providing a roadbed, excavating a foundation groove on the foundation at the position of the slope toe of the embankment, and erecting a formwork in the foundation groove from bottom to top to pour a concrete foundation in a layered mode;

when the concrete foundation is poured to the bottom surface of the embankment, the lower surface of the cushion layer is paved with the permeable geotextile, the geocell of the cushion layer is stretched and fixed, and the permeable material of the cushion layer is filled in the geocell of the cushion layer and is tamped tightly;

continuously pouring a concrete foundation, and paving the upper surface permeable geotextile of the cushion layer on the geocell of the cushion layer to obtain the cushion layer;

and continuously pouring the concrete foundation to the target height of the concrete foundation to obtain the concrete foundation.

Furthermore, the depth of the bottom surface of the concrete foundation in the foundation is greater than the depth of the frost line, and the depth difference between the bottom surface of the concrete foundation and the frost line is 0.5-0.6 m.

Furthermore, the reinforced and reinforced submerged roadbed also comprises an anchor rod;

the anchor rod penetrates through the geocell of the protective layer, the permeable geotextile of the protective layer and the embankment and then is fixedly connected with the reinforced layer;

the shape that protective layer, reinforcement layer and stock constitute is triangle-shaped.

Further, anchor rods are arranged on two sides of the reinforced and reinforced water-immersed roadbed, the number of the anchor rods on each side is multiple, the distance between every two adjacent anchor rods is 2-3 m, and the driving angle of the anchor rods from the protective layer is 10-30 degrees.

Further, the method also comprises the following steps after the embankment slope forms the protective layer:

installing a mold bag on the protective layer, wherein the mold bag is connected with the protective layer through a pin;

and (3) injecting mixed plowing soil and plant seeds into the mold bag, sealing the mold bag after the mold bag is filled to be compact, and spraying water on the upper surface of the mold bag for maintenance.

Furthermore, the top of the protective layer is 1.0-1.5 m higher than the designed water level of the roadbed.

Further, the design method of the reinforcement layer comprises the following steps:

step a: calculating the slope safety coefficient F of the submerged subgrade when no reinforcing layer is added;

step b: judging whether the slope needs to be provided with a reinforcement layer or not according to the design safety factor F';

when F' is more than F, a reinforcement layer needs to be arranged;

step c: calculating the total tension Tmax of the reinforcement layer required when the design safety factor of the roadbed slope is F';

step d: determining the tension tr of each reinforced layer;

and for the roadbed slope with the height h less than or equal to 6m, the reinforced layers are arranged at equal intervals along the height direction of the slope. Step e: determining the length L of the inner reinforced layer in the anchoring area outside the arc sliding surface _a Length L of the inner reinforcement layer in the anchoring zone _a Should not be less than 1m.

Step f: calculating the total length L of each layer of reinforced layer _T 。

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

a) According to the construction method for reinforcing the submerged road bed by the ribs, the cushion layer, the reinforcing layer, the protective layer and the reinforcing layer are respectively arranged around and inside the embankment, so that the cushion layer, the reinforcing layer, the protective layer and the reinforcing layer form a stable and relatively closed enclosure structure, an external water body can be isolated from the embankment on the basis of ensuring the water permeability of the road bed, the embankment is prevented from being softened and damaged under the action of water, the loss of embankment materials in the reinforced submerged road bed in water current invasion is effectively reduced, the embankment materials are prevented from being damaged and affected by water, and the stability and the durability of the reinforced submerged road bed are ensured. The reinforced and reinforced water-immersed roadbed of the embodiment is tested for the compactness, and the compactness can completely meet the standard requirement (the compactness is more than 94 percent) and basically can reach 96 percent.

b) According to the construction method for reinforcing the submerged roadbed by the ribs, the reinforcing layer, the protective layer and the cushion layer have a drainage function through the arrangement of the permeable geotextile, the holes among the permeable materials and the drain holes in the geocells jointly form a drainage channel, when the water level fluctuates, water flow in the embankment seeps out, the internal and external water pressures are consistent, so that seepage influence caused by difference between the internal and external water pressures is reduced, and loss of embankment materials is further reduced on the basis of ensuring the overall permeability of the roadbed.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings, in which like reference numerals refer to like parts throughout, are for the purpose of illustrating particular embodiments only and are not to be considered limiting of the invention.

Fig. 1 is a schematic structural view of a reinforced and reinforced submerged road bed in the construction method for reinforcing a submerged road bed by using ribs according to the first embodiment of the present invention;

fig. 2 is a schematic view of a partial structure of a reinforced and reinforced submerged road bed in the construction method for reinforcing a submerged road bed by using a reinforcement according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view taken along line a-a of FIG. 2;

FIG. 4 is a cross-sectional view taken along line b-b of FIG. 2;

fig. 5 is a schematic perspective view of a concrete foundation in the construction method for reinforcing a water-soaked road bed according to an embodiment of the present invention;

fig. 6 is a first design schematic diagram of a reinforcement layer in the construction method for reinforcing a water-soaked road bed by using a reinforcement provided in the first embodiment of the present invention;

fig. 7 is a second design schematic diagram of a reinforcement layer in the construction method for reinforcing a water-soaked road bed by using a reinforcement provided by the first embodiment of the present invention.

Reference numerals:

1-foundation; 2-an embankment; 3-way bed; 4-cushion layer; 5-reinforcing layer; 6-protective layer; 7-anchor rod; 8-concrete foundation; 81-slope section; 82-vertical section; 83-grooves; 9-a drain pipe; 10-molding a bag; 11-a ribbed layer.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.

Example one

The embodiment provides a construction method for reinforcing a submerged roadbed, which comprises the following steps with reference to fig. 1 to 7:

providing a roadbed 1, and forming a cushion layer 4 on the roadbed 1;

forming an embankment 2 by adopting a layered filling mode, and forming a reinforcing rib layer 11 in the embankment 2 in the process of forming the embankment 2;

forming a protective layer 6 on the slope surface of the embankment 2, and forming a reinforcing layer 5 on the top surface of the embankment 2;

forming a road bed 3 on the reinforcing layer 5 to obtain a reinforced and reinforced water-soaked road bed;

wherein, the cushion layer 4, the reinforcing layer 5 and the protective layer 6 enclose an accommodating space for accommodating the embankment 2, and the inner wall of the accommodating space is provided with permeable geotextile.

Illustratively, the concrete structure of the reinforced and reinforced submerged roadbed is as follows: the embankment foundation comprises a foundation 1, an embankment 2 and an embankment bed 3 which are sequentially arranged from top to bottom, wherein the cross section of the embankment 2 is trapezoidal, a cushion layer 4 is arranged on the bottom surface of the embankment 2, the cushion layer 4 is paved on the bottom surface of the embankment 2, a reinforcing layer 5 is arranged on the top surface of the embankment 2, a protective layer 6 is arranged on the slope surface of the embankment 2, the top of the protective layer 6 is higher than the design water level of a roadbed by 1.0-1.5 m, a reinforcing layer 11 is arranged in the embankment 2, one end of the reinforcing layer 11 is connected with the protective layer 6, an accommodating space for accommodating the embankment 2 is enclosed by the cushion layer 4, the reinforcing layer 5 and the protective layer 6, a permeable geotextile is arranged on the inner wall of the accommodating space, permeable materials are filled in a geocell to form the cushion layer 4, the reinforcing layer 5, the protective layer 6 and the reinforcing layer 11, the cushion layer 4, the reinforcing layer 5, the protective layer 6 and the reinforcing layer 11 are of the same structure, and the permeable materials (for example, gravels) filled in the geocell are adopted.

It should be noted that, in order to reduce the loss of the permeable material in the cushion layer 4, the bottom surface of the cushion layer 4 may also be provided with permeable geotextile, and the permeable geotextile is fully paved on the bottom surface of the cushion layer 4.

It should also be noted that, in consideration of the size limitation of the water-permeable geotextile, in practical application, a plurality of water-permeable geotextiles can be sewn to obtain a water-permeable geotextile whole body with a required size.

Compared with the prior art, in the construction method for reinforcing the submerged roadbed by the reinforcing ribs, the cushion layer 4, the reinforcing layer 5, the protective layer 6 and the reinforcing layer 11 are arranged around and inside the embankment 2 respectively, so that the cushion layer 4, the reinforcing layer 5, the protective layer 6 and the reinforcing layer 11 form a stable and relatively airtight enclosure structure, on the basis of ensuring that the roadbed is permeable, an external water body is isolated from the embankment 2, the embankment 2 is prevented from being softened and damaged under the action of water, the loss of the material of the embankment 2 in water flow invasion of the submerged roadbed by the reinforcing ribs is effectively reduced, the material of the embankment 2 is prevented from being affected by water damage to cause diseases, and the stability and durability of the reinforced submerged roadbed are ensured. The reinforced and reinforced water-immersed roadbed of the embodiment is tested for the compactness, and the compactness can completely meet the standard requirement (the compactness is more than 94 percent) and basically can reach 96 percent.

The geocell is a novel geosynthetic material with three-dimensional cellular structure, has that intensity is high, the percentage elongation is low, the lateral confinement ability is strong, the good characteristic of stand wear and tear, when using, through abundant stretch-draw and fill permeable materials such as rubble, can form the composite bed that has high strength and rigidity, and its cohesion also can show to be increased to can improve the stability that adds the muscle and consolidate the road bed that soaks. Three-dimensional cellular sheet of geotechnological check room has powerful lateral confinement effect to its inside rubble material that permeates water such as rubble, and the material that permeates water is tamped when indoor rubble of geotechnological check, and the net of geotechnological check room can form the crowded crushing stone body of hoop, increases the friction between the material that permeates water such as geotechnological check room and rubble to provide anchor power, avoid the indoor back of filling out of geotechnological check to slide along domatic emergence under the dead weight effect. Meanwhile, the geocell also has the advantages of high construction speed, controllable quality and the like, and has remarkable economic benefit and environmental benefit.

In addition, through the setting of geotechnological cloth that permeates water for back up coat 5, inoxidizing coating and bed course 4 all have the drainage effect, and the hole between the material that permeates water and the wash port on the geotechnological check room form drainage channel jointly, when the water level is undulant, make the interior rivers of embankment 2 ooze, make inside and outside water pressure reach unanimity, thereby reduce the seepage flow influence that interior and outside water head brought, on the basis of guaranteeing that the whole is permeated water of road bed, further reduce the loss of embankment 2 materials.

It should be noted that, in the design of the submerged embankment 2, the slope ratio of the slope below the water level is not steeper than 1 according to the existing traffic industry specification "highway subgrade design specification" JTGD 30-2015: 1.75, and fine-grained soil is not suitable for filling. However, the reinforced and reinforced submerged roadbed structure of the embodiment can effectively improve the stability and durability of the reinforced and reinforced submerged roadbed, so that the slope ratio of the reinforced and reinforced submerged roadbed side slope is 1:0.75 to 1.5, can reduce the occupied area and the earthwork amount, reduce the construction cost, reduce the damage of the surrounding environment, shorten the construction period and the like.

Illustratively, the material of the embankment 2 may be construction waste, the construction waste is used as the material of the embankment 2, and a large amount of construction waste is used as the internal material of the roadbed, so that the stacking of the construction waste can be effectively reduced, and the recycling and harmless utilization of the construction waste can be realized.

In order to further improve the wholeness of above-mentioned reinforcement reinforcing flooding road bed, above-mentioned reinforcement reinforcing flooding road bed still includes stock 7, and stock 7's one end and inoxidizing coating 6 fixed connection, stock 7's the other end pass behind inoxidizing coating 6 and the road bed with add muscle layer 11 fixed connection. Like this, through the setting of stock 7, can connect inoxidizing coating 6, road bed and reinforced layer 11 and become a whole, and the shape that inoxidizing coating 6, reinforced layer 11 and stock 7 constitute is triangle-shaped, further improves the stability that the above-mentioned reinforced road bed that soaks.

Exemplarily, the two sides of the reinforced and reinforced submerged roadbed are provided with a plurality of anchor rods 7, the distance between every two adjacent anchor rods 7 is 2-3 m, and the driving angle of the anchor rods 7 from the protective layer 6 is 10-30 degrees.

For the geocell, not only enough mechanical strength needs to be ensured, but also the water permeability of the geocell needs to be considered, so that the unit cell of the geocell needs to be of the following sizes: the cross section of the cell is in a diamond shape, the height of the cell is 5-15 cm, and the side length of the cell is 15-50 cm.

In order to further improve the water permeability of the geocell, the side wall of the unit cell of the geocell (namely the strip of the geocell) can be provided with a drain hole, and the diameter of the drain hole is 0.15-0.3 cm.

For the material of the geocell, in order to ensure that the geocell has enough mechanical strength, the material can be Polyethylene (PE), polypropylene (PP) or Polyester (PET), wherein the yield tension per unit width of a PE strip is more than or equal to 260N/cm, the yield elongation is less than or equal to 15%, and the longitudinal/transverse right-angle tearing strength is more than or equal to 200N; the breaking tension per unit width of the PP strips is more than or equal to 1200N/cm, and the breaking elongation is less than or equal to 15%; the unit width breaking tension of the PET strips is more than or equal to 1200N/cm, the breaking elongation is less than or equal to 15%, and the longitudinal/transverse right-angle tearing strength is more than or equal to 200N.

Similarly, in order to ensure the mechanical strength and the water permeability of the water-permeable geotextile, the mass per unit area of the water-permeable geotextile is 300-500 g/m ² The tensile strength is more than or equal to 10kN/m, the elongation at break is more than or equal to 50 percent, the tear strength is more than or equal to 0.5kN, the burst strength of CBR is more than or equal to 3.5kN/m, and the vertical permeability coefficient is 1 multiplied by 10 ^-1 cm/s～1×10 ^-3 cm/s。

In practical application, the stability and the durability of 2 bankss of embankment slope feet are great to the holistic influence of reinforced reinforcement flooding road bed, and in order to further improve the stability and the durability of reinforced reinforcement flooding road bed bottom, above-mentioned reinforced reinforcement flooding road bed is still including the concrete foundation 8 of locating 2 bankss of embankment, and the quantity of concrete foundation 8 is the multistage, and multistage concrete foundation 8 sets up along 2 vertical segmentation of embankments, is equipped with the subsiding crack between adjacent two sections concrete foundation 8. The broken stone concrete foundation 8 is adopted to protect the side slope of the embankment 2, the manufacturing cost is lower than that of conventional reinforced concrete, and the durability is higher than that of gabion protection.

Wherein, the concrete foundation 8 is constructed by gravel concrete, the upper end of the concrete foundation 8 is connected with the protective layer 6, the inner side is connected with the cushion layer 4, the two ends of the cushion layer 4 are embedded into the concrete foundation 8 with the depth of more than 60cm (for example, 60-100 cm), and the lower end is embedded into the foundation 1 so as to be fixedly connected into a whole. Because the concrete foundation 8 is a rigid structure and has higher stability, the concrete foundation 8 is additionally arranged on the two sides of the embankment 2, so that the stability and the durability of the reinforced and reinforced submerged roadbed bottom can be effectively improved; in addition, the upper end of the concrete foundation 8 is connected with the protective layer 6, the inner side of the concrete foundation is connected with the cushion layer 4, the protective layer 6 and the cushion layer 4 can be effectively fixed, and therefore the stability of the integral enclosure structure can be improved.

For the structure of concrete foundation 8, specifically, it includes slope section 81 and vertical section 82 from last to connecting gradually down, and the upper end of slope section 81 is connected with inoxidizing coating 6, and the inboard and the bed course 4 of vertical section 82 are connected, and the lower extreme of vertical section 82 is buried in ground 1.

In order to improve the connection stability between the slope section 81 and the protective layer 6, a groove 83 for accommodating a geocell is formed in one surface, facing the protective layer 6, of the slope section 81, the shape of the groove 83 is matched with that of the geocell, a water-permeable material is not filled in the geocell corresponding to the slope section 81, and the geocell corresponding to the slope section 81 is embedded in the groove 83, so that the stable connection between the slope section 81 and the protective layer 6 can be realized.

In order to ensure the structural strength of the concrete foundation 8, the height of the vertical section 82 is 1.0-1.5 m, and the height of the slope section 81 is 30-60 cm; similarly, in order to ensure the stability of the concrete foundation 8, the depth of the vertical section 82 embedded in the foundation 1 is greater than the frost line depth of the foundation 1, and the depth difference between the two is 0.5-0.6 m.

Considering that the installation of the concrete foundation 8 may affect the water permeability of the bottom of the embankment 2, the concrete foundation 8 is provided with a drain pipe 9 (for example, PVC pipe or one-way drain pipe 9) penetrating the concrete foundation 8, the water flow direction in the drain pipe 9 is from the inside of the embankment 2 to the outside of the embankment 2, and the water inlet end of the drain pipe 9 is buried in the embankment 2.

Specifically, the number of the water discharge pipes 9 is plural, the plural water discharge pipes 9 are horizontally distributed at equal intervals along the longitudinal direction of the roadbed, and illustratively, the horizontal interval between the adjacent water discharge pipes 9 is 2 to 4m. The water inlet section of the water discharge pipe 9 is embedded in the permeable geotextile and is inclined 3-5 degrees relative to the horizontal direction from the inside of the embankment 2 to the outside of the toe, so that the function of unidirectional water discharge from the inside of the toe of the embankment 2 to the outside of the toe is realized, and the function of regulating the water pressure inside and outside the toe of the embankment 2 is realized.

Illustratively, in order to improve the reinforcing effect of the reinforcement layers 11 on the whole roadbed, the number of the reinforcement layers 11 is multiple, the multiple reinforcement layers 11 are arranged at equal intervals in the vertical direction, and the lengths of the multiple reinforcement layers 11 are gradually increased along the direction from the cushion layer 4 to the reinforcement layer 5, that is, the reinforcement layers 11 are arranged in a non-equal length manner with a long top and a short bottom, the length of the reinforcement layer 11 at the top is the longest, and the length of the reinforcement layer 11 at the bottom is the shortest. It should be noted that, for the length of the reinforced layer 11, it needs to exceed the wet line of the roadbed by 3-5 m, and the distance between two adjacent reinforced layers 11 is 50-80 cm.

In order to improve the overall greening performance of the roadbed and realize the green protection of the roadbed slope surface, the reinforced and reinforced submerged roadbed further comprises a mold bag 10 arranged on one surface of the protective layer 6, which is far away from the embankment 2, wherein the mold bag 10 is used for plant growth, a plant growth base (such as planting soil) and plant seeds are placed in the mold bag 10, and it needs to be noted that the plant seeds can be selected according to the local growth environment of the reinforced and reinforced submerged roadbed, and the mold bag 10 is connected with the protective layer 6 through pins, wherein the diameter of the pins is 12-16 mm, and the length of the pins is 10-15 cm. Thus, the overall greening performance of the roadbed can be improved by the arrangement of the mold bags 10.

As for the structure of the mold bag 10, specifically, the sidewall of the mold bag 10 is a multi-layered structure including, from the inside to the outside, a first geotextile (e.g., geotextile), a support layer (e.g., rigid plastic sheet), and a second geotextile (e.g., geotextile); likewise, in order to promote plant growth on the basis of ensuring the structural strength of the mold bag 10, the bottom wall of the mold bag 10 is also a multi-layered structure including, from the inside to the outside, a first support net (e.g., a steel mesh), a porous interlayer (e.g., a porous scrim), a second support net (e.g., a steel mesh), and a water permeable layer (e.g., a water permeable geotextile).

Illustratively, the mold pocket 10 has a shape of a parallelogram prism, the upper and lower inclined surfaces of the mold pocket 10 are parallel, and the width of the mold pocket 10 is 0.8 to 1.5m.

In order to reinforce the embankment 2 by using the plant root system, the bottom of the mould bag 10 is provided with a through hole for the root system to grow, the unit cell of the geocell is in a spiral shape in the protective layer 6 corresponding to the mould bag 10, and the through hole corresponds to the position of the unit cell. Like this, the plant roots who grows out from mould bag 10 passes through the through-hole and gets into in the cell, because the cell shape is the spiral for plant roots can be followed the spiral and grown, thereby can consolidate ventilative material and embankment 2 in the geotechnological check room more effectively.

Specifically, when the reinforced and reinforced submerged roadbed comprises a foundation 1, an embankment 2, an embankment 3, a cushion layer 4, a reinforcing layer 5, a protective layer 6, an anchor rod 7, a concrete foundation 8, a drain pipe 9, a mold bag 10 and a reinforced layer 11, the construction method comprises the following steps:

step 1: providing a foundation 1, excavating a foundation groove on the foundation 1 at the toe position of an embankment 2, erecting a mold in the foundation groove from bottom to top to pour a concrete foundation in a layered mode, wherein the embedding depth of the bottom surface (namely a vertical section) of a concrete foundation 8 in the foundation 1 is greater than the depth of a frost line, and the depth difference between the bottom surface and the vertical section is 0.5-0.6 m;

and 2, step: when the concrete foundation 8 is poured to the bottom surface of the embankment 2, the lower surface of the cushion layer 4 is paved on the bottom surface of the embankment 2, the geocell of the cushion layer is paved, stretched and fixed on the lower surface of the cushion layer 4, the fixed geocell is required to ensure that the shape of each cell is consistent, and the geocell of the cushion layer 4 is filled with water-permeable materials of the cushion layer such as broken stones and the like and is tamped tightly;

and step 3: continuously pouring the concrete foundation 8, and paving the upper surface permeable geotextile of the cushion layer 4 on the geocell of the cushion layer 4 to obtain the cushion layer 4;

and 4, step 4: when the concrete foundation 8 is poured to the target position of the drain pipe 9, the drain pipe 9 is placed in a downward inclined mode relative to the horizontal direction, then the concrete foundation 8 is continuously poured to the target height of concrete, the concrete foundation 8 is obtained, and a settlement joint is arranged between the concrete foundations 8 of the adjacent construction sections;

and 5: adopting a horizontal layered filling and layered rolling mode to form an embankment 2 till the distance of water is 1.0m above the water level, and forming a reinforcement layer 11 in the embankment 2 in the process of forming the embankment 2 to obtain the embankment 2 and the reinforcement layer 11;

and 6: leveling the slope of the embankment 2, laying permeable geotextile of the protective layer 6 on the slope, laying, tensioning and fixing geocell of the protective layer 6 on the permeable geotextile of the protective layer 6, wherein the tensioned geocell is required to ensure that the shape of each unit cell is consistent, fixing the tensioned geocell through a clamping piece, arranging anchor rods 7 on the slope at intervals of 2-3 m, fixedly connecting the anchor rods 7 with a reinforced layer 11 after penetrating through the geocell of the protective layer 6, the permeable geotextile of the protective layer 6 and the embankment 2, filling permeable materials such as gravels into the geocell of the protective layer 6 from the bottom of the embankment 2 upwards, and tamping to be dense to obtain the protective layer 6;

and 7: paving permeable geotextile of the reinforcing layer 5 on the top surface of the embankment 2 in a full-length mode, paving, tensioning and fixing geocells of the reinforcing layer 5 in the permeable geotextile of the reinforcing layer 5, filling permeable materials such as broken stones in the geocells of the reinforcing layer 5, and then tamping and compacting to obtain the reinforcing layer 5; connecting the geocell of the protective layer 5 with the geocell of the reinforcing layer 5 by using a connecting piece;

and 8: installing a mold bag on the protective layer 6, connecting the mold bag 10 with the protective layer 6 through a pin, then injecting mixed plowing soil and plant seeds into the mold bag 10, sealing the mold bag after filling and compacting, and spraying water on the upper surface of the mold bag 10 for maintenance to ensure that plants grow well;

and step 9: and forming a road bed 3 on the reinforcing layer 5 according to design requirements to obtain the reinforced and reinforced soaking road bed.

Specifically, the method for designing the reinforcement layer 11 includes the following steps:

a, step a: calculating the slope safety coefficient F of the submerged roadbed when the reinforced layer 11 is not added;

in the formula, M _r Anti-slip bending moment (kN M) generated by self weight of filling soil for roadbed side slope, M _s The minimum value of the ratio of Mr to Ms on an arc sliding surface which takes the O point as the center of a circle is searched and calculated by changing the position of the O point at the center of the circle for the sliding bending moment (kN.m) generated by the self weight of the earth filled in the side slope of the roadbed;

wherein r is the arc radius of rotation (m); alpha (alpha) ("alpha") _i As the center of a circle O and B _i Dot-dash line OB _i Angle (degrees) to the vertical, wherein B _i Is the ith arc of a bar _i A midpoint of (a); m is the total number (number) of bars divided in the vertical direction; l. the _i The length (m) of the arc of the ith strip; c. C _i The total cohesion (kPa) of the i-th bar sliding surface;

effective internal friction angle (°) of sliding surface of ith bar; g _i Weight (kN) of the ith bar; f _i Normal force (kN) of the bottom surface of the ith bar;

F _i ＝(γ _i 'h _2i +γ _i h _1i )l _i

G _i ＝(γ _si h _2i +γ _i h _1i )b _i

in the formula, h _1i Height (m) of the i-th block wetting line; h is a total of _2i Height (m) below the i-th piece wetting line; gamma ray _i ' is the floating weight (kN/m) of the part below the wetting line of the ith piece ³ )，γ _si ' saturation gravity (kN/m) for the i-th piece to soak the lower part ³ )，γ _i The weight (kN/m) of the part above the wetting line of the ith block ³ )；

In the formula, gamma _di Is the dry weight (kN/m) of the ith bar ³ )；γ _w Is the water gravity (kN/m) ³ )；θ ₀ Water content (%) of the slope surface volume; theta _s The water content of the soil body in the slope body is (%);

in the formula, c _i ' is the effective cohesion (kPa) of the ith bar; psi _b The air inlet value (kPa) of the side slope soil body is set; theta _r The residual water content of the soil body of the side slope (%); h is ₀ Is the height (m) of the wetting line; beta is a parameter related to the grain size characteristics of the slope soil body; theta _i Volume water content (%) at the sliding surface of the ith bar;

in the formula, y is the height (m) of the point O at the center of the circle.

Step b: judging whether the side slope needs to be provided with the reinforcement layer 11 or not according to the design safety factor F';

when F' is less than or equal to F, no reinforcing rib layer is required to be arranged;

when F' is larger than F, designing a reinforced layer according to the steps c-F;

step c: calculating the total tension T of the reinforcement layer required when the design safety factor of the roadbed slope is F _max ；

T _max ＝max(T _th ,T _eq )

In the formula, T _th Calculating a value (kN/m) for the total tension of the ribbed layer; t is a unit of _eq The empirical value (kN/m) of the total tension of the reinforced layer is obtained.

Wherein gamma is the average gravity (kN/m) of the roadbed filling ³ ) N is the number of the reinforcement layers to be laid, b is the thickness (m) of each reinforcement layer, c _g Adding cohesive force (kPa) to the reinforced layer, k is the slope toe phi of the roadbed slope and the slope filling friction angle

And the influenced soil pressure coefficient q is the load (kN/m) of the top of the side slope.

In the formula, D ₀ For triaxial test sample diameter (m), epsilon of geocell reinforced soil _a Vertical strain of a triaxial test sample of the geocell reinforced soil, and K is geocell tensile stiffness (kN/m) and K _p Is a coefficient of passive earth pressure, a ₀ ～a ₅ To calculate the coefficients;

step d: for the roadbed slope with the height h less than or equal to 6m, the reinforced layers are arranged at equal intervals along the height direction of the slope;

and calculating the design required tension tr (kN/m) of each reinforced layer according to the vertical space Sv of the reinforced layers.

Wherein tn is the geocell node strength (kN/m), and tu is the geocell strip strength (kN/m);

step e: determining the length La of the reinforcement layer in the anchoring area outside the arc sliding surface, wherein the length La of the reinforcement layer in the anchoring area is not less than 1m;

in the formula, fz is the anti-pulling safety coefficient of the reinforced layer, F is the friction coefficient of the reinforced layer and the roadbed filling interface, and F is taken

Eta is the influence coefficient =0.8 of the nonlinear action between the reinforced layer and the roadbed filling, and sigmav is the vertical stress (kPa) covered on the reinforced layer.

Step f: the total length LT of each layer of the ribbed layer 11 is calculated.

The total length of each reinforced layer meets the requirement of overall stability of the roadbed slope.

In the formula, b 0-b 2 are calculated coefficients of the total length LT-O of the reinforced layer for ensuring the overall stability of the roadbed slope. B 0-b 2 are calculated by means of linear interpolation when the slope angles phi are between 30 o-45 o, 45 o-60 o.

The total length of each reinforced layer also ensures that the roadbed slope does not generate sliding instability along the geocell.

In the formula, r0 and r1 are calculation coefficients of the total length LT-DS of the reinforced layer for ensuring the roadbed slope to avoid sliding instability. When the slope angle phi is between 30 o-45 o and 45 o-60 o, r0 and r1 are calculated through linear interpolation.

The total length LT of each reinforced layer is the maximum value of LT-O and LT-DS and is arranged in the slope in equal length.

L _T ＝max(L _T-O ,L _T-DS )

In particular, when LT-DS > LT-O, the total length LT of each rib layer can also be uniformly reduced from the LT-DS at the bottom layer to the LT-O at the top layer, namely the total length of the j rib layer from bottom to top is as follows:

the above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. A construction method for reinforcing a submerged road bed by using ribs is characterized by comprising the following steps:

providing a roadbed, and forming a cushion layer on the foundation;

forming an embankment, and forming a reinforcing rib layer in the embankment forming process;

the cushion layer, the reinforcing layer and the protective layer form an accommodating space for accommodating the embankment, and the inner wall of the accommodating space is provided with permeable geotextile;

and filling the geocell with the permeable material to form a cushion layer, a reinforcing layer, a protective layer and a reinforcing layer respectively.

2. The method of constructing a reinforced and reinforced submerged road foundation according to claim 1, wherein said forming an embankment in which the reinforcement layer is formed in the embankment comprises the steps of:

3. The method of constructing a reinforced and submerged road bed according to claim 1, further comprising a concrete foundation provided on a toe of the embankment, the method comprising the steps of:

4. The method of constructing a reinforced and submerged road bed according to claim 3, wherein the depth of the bottom surface of the concrete foundation buried in the ground is greater than the depth of the frost line, and the difference between the depths is 0.5 to 0.6m.

5. The method of constructing a reinforced and submerged road bed according to claim 2, wherein the reinforced and submerged road bed further comprises anchor rods;

6. The construction method for reinforcing the submerged road bed according to claim 5, wherein anchor rods are arranged on both sides of the reinforced submerged road bed, the number of the anchor rods on each side is multiple, the distance between two adjacent anchor rods is 2-3 m, and the driving angle of the anchor rods from the protective layer is 10-30 degrees.

7. The method for constructing a reinforced and reinforced submerged roadbed according to claim 2, wherein the method further comprises the following steps after the embankment slope is provided with the protective layer:

and (3) injecting the mixed plowing soil and plant seeds into the mold bag, sealing the mold bag after the mold bag is tightly filled, and spraying water on the upper surface of the mold bag for maintenance.

8. The method for constructing a reinforced and reinforced submerged road foundation according to any one of claims 1 to 7, wherein the top of the protective layer is 1.0 to 1.5m above the design water level of the road foundation.

9. The method for constructing a reinforced/water-soaked road bed according to any one of claims 1 to 7, wherein the method for designing the reinforcing layer comprises the steps of:

step a: calculating the slope safety coefficient F of the submerged roadbed when no reinforcing layer is added;

step b: judging whether the slope needs to be provided with a reinforcement layer or not according to the design safety coefficient F ', and if the F' is more than F, arranging the reinforcement layer;

Step d: determining tension t of each reinforced layer _r ；

For the roadbed slope with the height h less than or equal to 6m, the reinforced layers are arranged at equal intervals along the height direction of the slope;

step e: determining the length L of the inner reinforced layer of the anchoring area outside the arc sliding surface _a Length L of the inner reinforcement layer in the anchoring zone _a Should not be less than 1m;

step f: calculating the total length L of each layer of reinforcement layer _T 。