CN113005838A

CN113005838A - Special roadbed structure above subway and construction method thereof

Info

Publication number: CN113005838A
Application number: CN202110269497.7A
Authority: CN
Inventors: 陈顺平; 陈亮; 郄磊堂; 周少伟; 熊丽
Original assignee: Fujian Green Tree Energy Saving Technology Co Ltd
Current assignee: Fujian Green Tree Energy Saving Technology Co Ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2021-06-22

Abstract

The invention discloses a special subgrade structure above the subway and a construction method thereof in the technical field of subgrade structures in subway sections. In the pavement structure layer, concrete retaining walls are arranged on both sides of the lightweight foam concrete roadbed, and the outer side of the concrete retaining wall is provided with soil-filled slope protection. Concrete reduces the weight of the embankment structure to avoid the phenomenon of foundation settlement in the case of excessive load, and is more stable. Through the adjustment and selection of pile types and embedded forms, as well as the strengthening application of frame piles and beams, lightweight foamed concrete is made. The stable connection between the subgrade and the foundations of different geology can effectively reduce the differential settlement of the subgrade, thereby ensuring the safe operation of the subway.

Description

Special roadbed structure above subway and construction method thereof

Technical Field

The invention relates to the technical field of roadbed structures of subway sections, in particular to a special roadbed structure above a subway and a construction method thereof.

Background

The existing soft soil foundation pouring mode is to adopt a sand piling layer to combine with a concrete roadbed layer to form a roadbed structure with certain thickness and density. However, the existing embankment structure has overlarge weight, the foundation settlement phenomenon is easy to occur under the condition of overlarge load, and the structural stability needs to be improved.

Along with the continuous increase of urban ground traffic demands, the grade of urban roads is continuously improved, and the road networks are also more and more dense, so that more and more road sections overlapped with the shield tunnels for operating subways are bound to be arranged. Compared with a ground structure, the underground structure has the advantages that the engineering safety problem is more hidden, the repairing difficulty is higher, and the related engineering construction close to the operation of the subway shield tunnel is strictly controlled and restricted. The load of conventional road structure layer often can exceed former earthing load, produces additional stress to operation subway shield tunnel, arouses the settlement of tunnel interval, influences operation subway shield tunnel structure's stability and safety.

The pouring mode of the traditional soft soil foundation is to adopt a sand piling layer to be combined with a concrete roadbed layer to form a roadbed structure with certain thickness and density. However, the existing embankment structure has overlarge weight, the foundation settlement phenomenon is easy to occur under the condition of overlarge load, and the structural stability needs to be improved.

Based on the above, the invention designs a special roadbed structure above the subway and a construction method thereof, so as to solve the problems.

Disclosure of Invention

The invention aims to provide a special roadbed structure above a subway and a construction method thereof, so as to solve the technical problems.

In order to realize the purpose, the invention provides the following technical scheme: the utility model provides a special roadbed structure in subway top, is including laying the light foam concrete road bed between road surface and subway tunnel top road bed, the road surface structural layer has been laid at the top of light foam concrete road bed, the both sides of light foam concrete road bed are provided with the concrete barricade, the outside of concrete barricade is provided with the bank protection of filling out, the bottom of light foam concrete road bed and both sides bank protection of filling out is equallyd divide and is do not provided with the stake.

Preferably, the light foam concrete roadbed and the piles at the bottoms of the two side filling revetments are cement mixing piles which are distributed in a rectangular lattice shape of a horizontal and vertical array.

Preferably, the inside of light foam concrete road base is inlayed and is provided with frame pile beam, the cement stirring stake set up in frame pile beam bottom portion distributes in the both sides and the centre in two-way subway tunnel, frame pile beam is rectangle latticed structure, the cement stirring stake set up in the net node below of frame pile beam, the top of cement stirring stake is provided with the cement stirring pile cap.

Preferably, the light foam concrete roadbed and the piles at the bottoms of the two side soil filling revetments are CFG rigid piles.

Preferably, the top ends of the CFG rigid piles at the distribution positions interfering and colliding with subway pipelines, culverts and retaining wall structures are chiseled to be lower than other CFG rigid piles or are offset laterally to avoid.

Preferably, the overhead arrangement structure of the CFG rigid piles is a rectangular lattice structure of a horizontal-vertical array, and CFG rigid pile caps are arranged at the top ends of the CFG rigid piles.

Preferably, a composite mattress layer is arranged between the light foam concrete roadbed, the bottoms of the two side soil-filled revetments and the top end of the pile.

Preferably, the composite mattress layer comprises a first gravel sand distribution cushion layer, a first bidirectional steel-plastic geogrid, a second gravel sand distribution cushion layer and a second bidirectional steel-plastic geogrid from bottom to top in sequence.

Preferably, the two sides of the soil filling and protecting slope are both provided with drainage channels, the road surface structure layer road surface is provided with slopes forming% in a descending manner from the middle to the two sides, the slope feet of the soil filling and protecting slope are positioned at the outer side of the mattress layer and are provided with protection feet of broken stone filling, dry masonry or mortar masonry, and drainage holes for draining seepage water in the mattress layer to the drainage channels are formed in the protection feet.

A construction method of a special roadbed structure above a subway comprises the following construction steps:

the method comprises the following steps: and prefabricating a cement mixing pile and a CFG rigid pile for later use.

Step two: and (3) piling holes on the foundation, if the upper part and the lower part of the subway tunnel are provided with soft soil layers, embedding cement mixing piles, and if only the upper part of the subway tunnel is provided with the soft soil layers, embedding CFG rigid piles, wherein the cement mixing piles are distributed on two sides and in the middle of the bidirectional subway tunnel.

Step three: if the upper part and the lower part of the subway tunnel are provided with soft soil layers, pouring cement mixing pile caps at the upper ends of the cement mixing piles; and if only a soft soil layer exists on the upper part of the subway tunnel, pouring a CFG rigid pile cap at the upper end of the CFG rigid pile, and pouring a frame pile beam on the cement stirring pile cap.

Step four: if the upper part and the lower part of the subway tunnel are both provided with soft soil layers, the mattress layer is paved at a height higher than the ground line, and if only the upper part of the subway tunnel is provided with the soft soil layers, the mattress layer is paved at a height higher than the ground line.

Step five: concrete retaining walls are erected on the two sides of the road on the mattress layer, and a light foam concrete roadbed is poured between the concrete retaining walls on the two sides.

Step six: and earth-filled revetments are arranged on two sides of the lightweight foam concrete roadbed.

Step seven: if only the upper part of the subway tunnel has a soft soil layer, water drainage grooves are arranged on two sides of the filled slope protection, and water drainage holes are arranged at the positions, located on the outer side of the mattress layer, of slope feet of the filled slope protection.

Compared with the prior art, the invention has the beneficial effects that:

according to the special roadbed structure above the subway, the light foam concrete is adopted to replace a traditional sand-piled layer to be combined with a concrete roadbed layer, the foam concrete is a manual material which is light, good in integrity and convenient to construct, the required raw materials are water, cement and foaming agents, the roadbed is filled with the foam concrete to reduce the load effect on the running subway shield tunnel, the weight of the embankment structure is reduced to avoid the foundation settlement phenomenon under the condition of overlarge load, and the roadbed structure above the subway is more stable.

The light foam concrete roadbed of the special roadbed structure above the subway and the bottoms of the filling revetments at two sides are respectively provided with the piles, the distribution form, the embedding depth and the connection structure relationship between the pile caps and the light foam concrete roadbed can be flexibly adjusted and applied according to the soft soil property adaptability of the actual foundation, and the light foam concrete roadbed and the foundations with different geology can be stably connected through the adjustment selection of the pile type and the embedding form and the reinforced application of the frame pile beams, so that the differential settlement of the original roadbed caused by the vibration filling of a new roadbed can be effectively reduced, and the operation safety of the subway can be ensured.

According to the invention, the composite mattress layers are arranged between the light foam concrete roadbed of the special roadbed structure above the subway, the bottoms of the two side filling slope protectors and the pile top ends, and the mattress layers mainly play a role in adjusting the uneven settlement of the foundation, so that the leveling effect is achieved; the toe of slope protection of filling up simultaneously is located mattress pad layer outside department and is provided with rubble filling, dry-laying rubble or grout the banket of rubble, opens to be equipped with in the banket to be used for the infiltration in the mattress pad layer to drain to the outlet sluices of water drainage tank can isolated partial moisture, drainage with higher speed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.

FIG. 1 is a schematic structural view of the invention in an unused pile state;

FIG. 2 is a schematic structural view of a pile in use according to the present invention;

FIG. 3 is a schematic diagram of a cement mixing pile structure according to the present invention;

FIG. 4 is a schematic diagram of a pile distribution structure when cement mixing piles are used in the present invention;

FIG. 5 is a schematic structural view of a CFG rigid pile used in the present invention;

FIG. 6 is a schematic view of the pile distribution structure of the present invention using CFG rigid piles;

FIG. 7 is a schematic structural view of the foot protector using gravel packing according to the present invention;

FIG. 8 is a schematic view of the foot protector using dry masonry stones according to the present invention;

fig. 9 is a schematic structural view of the foot protector using the grouted rubble according to the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1-light foam concrete pavement, 2-pavement structure layer, 3-concrete retaining wall, 4-filling revetment, 5-pile, 51-cement mixing pile, 52-CFG rigid pile, 53-cement mixing pile cap, 54-CFG rigid pile cap, 6-frame pile beam, 7-composite mattress layer, 71-first gravel sand cushion layer, 72-first bidirectional steel-plastic geogrid, 73-second gravel sand cushion layer, 74-second bidirectional steel-plastic geogrid, 8-drainage groove, 9-drainage hole and 10-toe guard.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Referring to fig. 1-4, the present invention provides a technical solution: a special roadbed structure above a subway comprises a light foam concrete roadbed 1 laid between a road surface and a roadbed above a subway tunnel, wherein the foam concrete is a light artificial material with good integrity and convenient construction, the required raw materials are water, cement and a foaming agent, the roadbed is filled with the foam concrete to reduce the load effect on the running subway shield tunnel, the weight of the embankment structure is reduced to avoid the settlement of the roadbed under the condition of overlarge load, and the roadbed structure above the subway has higher stability; a pavement structure layer 2 is laid on the top of a light foam concrete roadbed 1, concrete retaining walls 3 are arranged on two sides of the light foam concrete roadbed 1, filling protection slopes 4 are arranged on the outer sides of the concrete retaining walls 3, piles 5 are respectively arranged at the bottoms of the light foam concrete roadbed 1 and the filling protection slopes 4 on the two sides, cement mixing piles 51 are arranged at the bottoms of the light foam concrete roadbed 1 and the filling protection slopes 4 on the two sides and are distributed in a rectangular lattice shape of a transverse and longitudinal array, a frame pile beam 6 is embedded and arranged in the light foam concrete roadbed 1, the cement mixing piles 51 are arranged at the bottom of the frame pile beam 6 and are distributed on two sides and in the middle of a bidirectional subway tunnel, the frame pile beam 6 is in a rectangular lattice structure, the cement mixing piles 51 are arranged below grid nodes of the frame pile beam 6, and a cement mixing pile cap 53 is arranged at the top end of the cement mixing piles 51; in this embodiment, the distribution application mode of cement mixing stake 51 is mainly applicable to the condition that there are weak soil layers in subway tunnel upper portion and lower part, through extension cement mixing stake 51 to and add the mode of frame pile roof beam 6 and effectively reduce the difference that causes original road bed because of the vibration that the new road bed was filled and subside, thereby guarantee the operation safety of subway.

The construction method of embodiment 1, comprising the following construction steps:

the method comprises the following steps: the precast cement mixing pile 51 is precast for standby.

Step two: holes are formed in the foundation in a piling mode, cement mixing piles 51 are buried, and the cement mixing piles 51 are distributed on the two sides and the middle of the bidirectional subway tunnel.

Step three: pouring a cement mixing pile cap 53 at the upper end of the cement mixing pile 51; if the upper part and the lower part of the subway tunnel are provided with soft soil layers, the frame pile beam 6 is poured on the cement mixing pile cap 53.

Step four: the mattress layer 7 is laid at a height above the ground line.

Step five: concrete retaining walls 3 are erected on the two sides of the road on the mattress layer 7, and a light foam concrete roadbed 1 is poured between the concrete retaining walls 3 on the two sides.

Step six: and earth-filled revetments 4 are arranged on two sides of the light foam concrete roadbed 1.

Example 2

Referring to fig. 1-2 and 5-9, the present invention provides a technical solution: a special roadbed structure above a subway comprises a light foam concrete roadbed 1 paved between a road surface and a roadbed above a subway tunnel, wherein a road surface structure layer 2 is paved on the top of the light foam concrete roadbed 1, concrete retaining walls 3 are arranged on two sides of the light foam concrete roadbed 1, soil-filled protective slopes 4 are arranged on the outer sides of the concrete retaining walls 3, and piles 5 are respectively arranged at the bottoms of the light foam concrete roadbed 1 and the soil-filled protective slopes 4 on the two sides; the light foam concrete roadbed 1 and the piles 5 at the bottoms of the two side earth-filled revetments 4 are CFG rigid piles 52, the top ends of the CFG rigid piles 52 with the distribution positions interfering with subway pipelines, culverts and retaining wall structures are chiseled lower than other CFG rigid piles 52 or are offset laterally to avoid, the overlooking arrangement structure of the CFG rigid piles 52 is a rectangular lattice structure of a horizontal and vertical array, the top ends of the CFG rigid piles 52 are provided with CFG rigid pile caps 54, a composite mattress layer 7 is arranged between the bottoms of the light foam concrete roadbed 1 and the two side earth-filled revetments 4 and the top ends of the piles 5, the composite mattress layer 7 sequentially comprises a first gravel sand cushion layer 71, a first bidirectional steel-plastic geogrid 72, a second gravel sand cushion 73 and a second bidirectional steel-plastic geogrid 74 from bottom to top, both sides of the earth-filled revetments 4 are provided with drainage channels 8, the pavement structure layer 2 is provided with slopes forming 2% by vertically, the slope foot of the soil-filling slope protection 4 is provided with a foot protector 10 for filling broken stones, dry-laying rubbles or grouted rubbles at the outer side of the mattress layer 7, a water drainage hole 9 for draining the seepage water in the mattress layer 7 to a water drainage tank 8 is arranged in the foot protector, and the mattress layer mainly plays a role in adjusting the uneven settlement of the foundation to achieve the leveling effect; meanwhile, the slope foot of the soil filling slope protection 4 is provided with a foot protector 10 for broken stone filling, dry stone or mortar stone at the outer side of the mattress layer 7, and a water drainage hole 9 for draining the water seepage in the mattress layer 7 to the water drainage groove 8 is arranged in the foot protector to isolate partial water and accelerate water drainage.

The construction method of embodiment 2, comprising the following construction steps:

the method comprises the following steps: prefabricated CFG rigid piles 52 are ready for use.

Step two: holes are drilled in the ground and CFG rigid piles 52 are embedded.

Step three: and pouring a CFG rigid pile cap 54 at the upper end of the CFG rigid pile 52.

Step four: a mattress layer 7 is laid at a height above the ground line.

Step seven: and drainage grooves 8 are arranged on two sides of the earth-filled protection slope 4, and drainage holes 9 are arranged at the outer side of the mattress layer 7 at the slope feet of the earth-filled protection slope 4.

In the description of the invention, it is to be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "other end", "upper", "one side", "top", "inner", "front", "center", "two ends", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the invention.

In the present invention, unless otherwise specifically stated or limited, the terms "mounted," "disposed," "connected," "fixed," "screwed" and the like are to be construed broadly, e.g., as being fixedly connected, detachably connected, or integrated; can be mechanically or electrically connected; the terms may be directly connected or indirectly connected through an intermediate, and may be communication between two elements or interaction relationship between two elements, unless otherwise specifically defined, and the specific meaning of the terms in the invention is understood by those skilled in the art according to specific situations.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A special roadbed structure above subway is characterized in that: including laying light foam concrete road bed (1) between road surface and subway tunnel top road bed, road surface structural layer (2) have been laid at the top of light foam concrete road bed (1), the both sides of light foam concrete road bed (1) are provided with concrete barricade (3), the outside of concrete barricade (3) is provided with filler slope protection (4), the bottom of light foam concrete road bed (1) and both sides filler slope protection (4) is equallyd divide and is do not be provided with stake (5).

2. The special roadbed structure above the subway, as claimed in claim 1, wherein: the lightweight foam concrete roadbed (1) and the piles (5) at the bottoms of the two side soil filling revetments (4) are cement mixing piles (51) which are distributed in a rectangular lattice shape in a horizontal and vertical array.

3. The special roadbed structure above the subway, as claimed in claim 2, wherein: the inside of light foam concrete road bed (1) is inlayed and is provided with frame pile roof beam (6), cement stirring stake (51) set up in frame pile roof beam (6) bottom and distribution are in both sides and the centre in two-way subway tunnel, frame pile roof beam (6) are rectangle latticed structure, cement stirring stake (51) set up in the net node below of frame pile roof beam (6), the top of cement stirring stake (51) is provided with cement stirring pile cap (53).

4. The special roadbed structure above the subway, as claimed in claim 1, wherein: the lightweight foam concrete roadbed (1) and the piles (5) at the bottoms of the two side filling revetments (4) are CFG rigid piles (52).

5. The special roadbed structure above the subway, as claimed in claim 4, wherein: the top ends of the CFG rigid piles (52) at the distribution positions interfering with subway pipelines, culverts and retaining wall structures are chiseled to be lower than other CFG rigid piles (52) or are offset laterally to avoid.

6. The special roadbed structure above the subway, as claimed in claim 4, wherein: the overhead arrangement structure of the CFG rigid piles (52) is a rectangular lattice structure of a horizontal and vertical array, and CFG rigid pile caps (54) are arranged at the top ends of the CFG rigid piles (52).

7. The special roadbed structure above the subway, as claimed in claim 4, wherein: and composite mattress layers (7) are arranged between the bottoms of the lightweight foam concrete roadbed (1) and the two side soil filling protection slopes (4) and the top ends of the piles (5).

8. The special roadbed structure above the subway, as claimed in claim 7, wherein: the composite mattress layer (7) comprises a first gravel sand distribution layer (71), a first bidirectional steel-plastic geogrid (72), a second gravel sand distribution layer (73) and a second bidirectional steel-plastic geogrid (74) from bottom to top in sequence.

9. The special roadbed structure above the subway, as claimed in claim 6, wherein: fill out native bank protection (4) both sides and all be provided with water drainage tank (8), pavement structure layer (2) road surface is provided with the slope that forms 2% by middle to both sides vertical drop, the slope foot that fills out native bank protection (4) is located mattress bed layer (7) outside department is provided with banket (10) of rubble filling, dry-laying rubble or thick-laying rubble, set up in the banket be used for with the infiltration in mattress bed layer (7) arrange to water drainage tank (8) outlet (9).

10. The construction method of a special roadbed structure above the subway according to any one of the claims 1-9, comprising the following construction steps:

the method comprises the following steps: and prefabricating a cement mixing pile (51) and a CFG rigid pile (52) for standby.

Step two: and (2) piling holes on the foundation, if soft soil layers exist on the upper part and the lower part of the subway tunnel, burying cement mixing piles (51), and if the soft soil layers exist on the upper part of the subway tunnel only, burying CFG rigid piles (52), wherein the cement mixing piles (51) are distributed on two sides and the middle of the bidirectional subway tunnel.

Step three: if the upper part and the lower part of the subway tunnel are provided with soft soil layers, pouring a cement mixing pile cap (53) at the upper end of the cement mixing pile (51); and if only a soft soil layer exists at the upper part of the subway tunnel, pouring a CFG rigid pile cap (54) at the upper end of the CFG rigid pile (52), and pouring a frame pile beam (6) on the cement mixing pile cap (53).

Step four: if the upper part and the lower part of the subway tunnel are both provided with soft soil layers, the mattress layer (7) is paved at a height higher than the ground line, and if only the upper part of the subway tunnel is provided with the soft soil layers, the mattress layer (7) is paved at a height higher than the ground line.

Step five: concrete retaining walls (3) are erected on the two sides of the road on the mattress layer (7), and a light foam concrete roadbed (1) is poured between the concrete retaining walls (3) on the two sides.

Step six: and earth-filled revetments (4) are arranged on two sides of the light foam concrete roadbed (1).

Step seven: if only a soft soil layer exists on the upper part of the subway tunnel, water drainage grooves (8) are arranged on two sides of the earth-filled protection slope (4), and water drainage holes (9) are formed in the positions, located on the outer side of the mattress layer (7), of slope feet of the earth-filled protection slope (4).