CN114164727A - Transverse drainage type composite geomembrane and transverse drainage method - Google Patents

Abstract

The invention provides a transverse drainage type composite geomembrane and a transverse drainage method. The compound geomembrane of horizontal drainage type includes: the anti-seepage layer, the geotextile and a plurality of drainage belts are arranged on the anti-seepage layer at intervals; the drainage belts are provided with drainage channels which extend in parallel along the longitudinal direction and are densely distributed, and two adjacent drainage belts and the impermeable layer between the two drainage belts surround to form a drainage ditch capable of draining water directionally; the geotextile is tightly attached to the top surfaces of the drainage strips and the impermeable layer. The composite geomembrane provided by the invention can prevent water from downwardly permeating into a roadbed, and increases a roadbed transverse drainage channel under the condition of ensuring that drainage does not take away roadbed soil particles, thereby being beneficial to roadbed drainage, effectively solving the problem caused by unsmooth drainage part of the existing roadbed, and improving the service durability of the roadbed; the water is stopped by the drainage belt to move longitudinally along the surface of the impervious barrier to the roadbed, so that the retention time of water in the roadbed is effectively reduced, and the roadbed maintenance is facilitated.

Description

Transverse drainage type composite geomembrane and transverse drainage method

Technical Field

The invention relates to the technical field of railway and highway subgrade drainage, in particular to a transverse drainage type composite geomembrane and a transverse drainage method.

Background

The infiltration of surface water on the base surfaces of railways and highways is one of main defects of the subgrade, the infiltration of the surface water cannot be timely discharged, the subgrade is caused to be muddy and frost-swelled, the subgrade maintenance work is increased, the hidden danger is brought to safe operation, and particularly ballastless railways are more easily damaged by the hidden danger.

The shapes of the railway and highway subgrades are triangular, the center is high, the two sides are low, 4% of drainage slopes are generally arranged on the top surface of the subgrade surface layer, the bottom surface of the subgrade surface layer and the top surface of the subgrade bottom layer of the subgrade body, and water in the subgrade body is drained by utilizing the formed transverse drainage slopes. The geomembrane is usually adopted as an anti-seepage drainage structure, and is laid on the surface of a roadbed or below the surface of the roadbed by a certain depth according to the shape of a roadbed surface, and medium sand which is 5cm behind the geomembrane is usually laid on the upper part and the lower part of the geomembrane to be used as a protective layer. Therefore, after the surface water on the upper part permeates into the film layer, the surface water flows to the downhill direction along the film layer under the action of the transverse slope of the roadbed and finally flows out of the roadbed body. As shown in fig. 1, the geomembrane is composed of a geotextile 1 and a plastic film 7, wherein the plastic film 7 is used as a seepage-proofing material, and surface water flows along the plastic film 7 in the downward slope direction after permeating, and finally flows out of the roadbed body.

However, in the existing geomembrane seepage-proofing and drainage structure, surface water permeates and flows longitudinally and transversely along the membrane surface and finally flows out of the roadbed body, so that the flowing distance and flowing time of the water on the membrane are increased, the retention time of the water in the roadbed is prolonged, and the roadbed maintenance is not facilitated. In addition, the existing geomembrane structure is not provided with a direct drainage channel, and the horizontal and vertical drainage of the geotextile on the membrane is small, so that the requirement on the drainage performance of the roadbed is not met; the geomembrane structure has the defect of poor durability, and fine soil particles permeate into the geotextile in the long-term drainage process, so that transverse and longitudinal drainage channels of the geotextile are easily blocked or drainage is unsmooth.

Disclosure of Invention

In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a transverse drainage type composite geomembrane, which can effectively reduce the retention time of water in a roadbed, increase the transverse drainage of the roadbed, and solve the problem of unsmooth drainage of the existing roadbed.

The invention provides a transverse drainage type composite geomembrane which comprises an impermeable layer, geotextile and a plurality of drainage belts, wherein the impermeable layer is arranged on the geotextile; the drainage belt is of a belt-shaped structure and is provided with drainage channels which extend in parallel in the longitudinal direction and are densely distributed, the drainage belts are distributed on the anti-seepage layer at intervals in the direction perpendicular to the drainage channels, the bottom surfaces of the drainage belts are fixedly connected with the top surface of the anti-seepage layer and are tightly attached to the top surface of the anti-seepage layer, and drainage grooves capable of draining water directionally are formed by the two adjacent drainage belts and the anti-seepage layer between the two drainage belts in a surrounding manner; the geotextile is tightly attached to the top surfaces of the drainage strips and the impermeable layer.

A plurality of drainage belts are arranged between the impermeable layer and the geotextile at intervals, so that the geotextile can ensure that the drainage does not take the particles of the walking foundation soil body; the impermeable layer can prevent water from permeating into the roadbed downwards; by arranging a plurality of drainage belts on the impervious layer at intervals, a transverse direct drainage channel of the roadbed can be added, the drainage quantity is increased, the blockage is avoided, a drainage structure matched with the transverse drainage gradient of the roadbed is formed, the drainage of the roadbed is facilitated, the problem caused by unsmooth drainage part of the existing roadbed is effectively solved, the sinking, slurry leakage and frost damage of the roadbed caused by poor drainage of the roadbed are effectively solved, and the service durability of the roadbed is improved; meanwhile, the transverse drainage channels are additionally arranged, so that directional drainage can be realized, and the drainage belt is utilized to prevent surface water from permeating into the roadbed and then longitudinally moving towards the roadbed along the surface of the impermeable layer, so that the retention time of the water in the roadbed is effectively reduced, and the roadbed maintenance is facilitated.

Preferably, the drainage belt is a capillary drainage belt, the drainage channel comprises a water guide slot hole formed in the capillary drainage belt and a capillary groove formed in the top surface of the capillary drainage belt and communicated with the water guide slot hole, and the cross-sectional area of the water guide slot hole is larger than that of the capillary groove. The capillary drainage belt automatically achieves the functions of water absorption, filtration, sealing and drainage by utilizing the capillary suction effect, the siphon effect, the gravity effect and the surface tension, can effectively prevent particles from blocking, enlarge the drainage range, actively drain water by negative pressure suction and suction, and prevent water from leaking back when the surface tension generates negative pressure.

Preferably, the thickness of the capillary drainage belt is not less than 2mm, water guide groove holes with the diameter of 0.8-1.2 mm are formed in the width direction of the capillary drainage belt every 1-2 mm, the aperture ratio is greater than 20%, and the width of the capillary groove is 0.1-0.5 mm. The capillary drainage strip designed in this way can ensure that the capillary drainage strip has the capillary action and the siphoning action, and meanwhile, the drainage channel can be opened as much as possible when the aperture ratio is more than 20%, so that the drainage quantity of the capillary drainage strip is improved.

Preferably, the thickness of the capillary drainage strip is not less than 2mm, water guide slotted holes with the diameter of 1mm are formed in the width direction of the capillary drainage strip every 1.5mm, and the width of the capillary groove is 0.3 mm. The capillary drainage belt designed in this way can ensure that the capillary drainage belt has the capillary action and the siphon action, and can be provided with a drainage channel as much as possible, so that the drainage quantity of the capillary drainage belt is improved.

Preferably, the bottom of the impermeable layer is also provided with geotextile, and the geotextile is tightly attached to the bottom surface of the impermeable layer. The geotextile is additionally arranged at the bottom of the impermeable layer, so that the impermeable layer can be prevented from being pierced from the bottom.

Preferably, the drainage belt is made of high molecular polymer, preferably soft PVC material, and the flexible design of the drainage belt ensures that water in the pit can be drained through siphonage when the pit is formed on the road base surface.

Preferably, the geotextile is a non-woven geotextile made of polymer fibers.

Preferably, the geotextile is made of polyester or polypropylene, and the thickness of the geotextile is 1-5 mm.

The polyester or polypropylene polymer fiber material has the characteristics of pressure resistance, corrosion resistance and high strength, and ensures that the geotextile also has the effects of draining, filtering soil particles and preventing puncture and has long service life.

Preferably, the barrier layer is made of high molecular polymer, preferably high density polyethylene virgin resin, and has a thickness of 0.3mm to 1.5 mm.

The high molecular polymer, especially the high density polyethylene material has the characteristics of pressure resistance, corrosion resistance and high strength, so that the anti-seepage layer has high fatigue resistance, and the anti-seepage effect and the long service life of the anti-seepage layer are ensured.

The invention also provides a lateral drainage method for absorbing and collecting water in a roadbed and discharging the water out of the roadbed, the lateral drainage type composite geomembrane is laid in a roadbed basic body with a lateral gradient, a drainage ditch and a drainage channel in the composite geomembrane extend along the lateral direction of the roadbed, and excessive water in the roadbed basic body is transversely drained along a line through the drainage ditch and the drainage channel.

Compared with the prior art, the transverse drainage type composite geomembrane provided by the invention has the advantages that the plurality of drainage belts are arranged between the impermeable layer and the geotextile at intervals, and the geotextile can ensure that the drainage does not carry walking foundation soil particles; the impermeable layer can prevent water from permeating into the roadbed downwards; by arranging a plurality of drainage belts on the impervious layer at intervals, a transverse direct drainage channel of the roadbed can be added, the drainage quantity is increased, the blockage is avoided, a drainage structure matched with the transverse drainage gradient of the roadbed is formed, the drainage of the roadbed is facilitated, the problem caused by unsmooth drainage part of the existing roadbed is effectively solved, the sinking, slurry leakage and frost damage of the roadbed caused by poor drainage of the roadbed are effectively solved, and the service durability of the roadbed is improved; meanwhile, the transverse drainage channels are additionally arranged, so that directional drainage can be realized, and the drainage belt is utilized to prevent surface water from permeating into the roadbed and then longitudinally moving towards the roadbed along the surface of the impermeable layer, so that the retention time of the water in the roadbed is effectively reduced, and the roadbed maintenance is facilitated. The drainage belt is preferably a capillary drainage belt with flexible deformation and siphon drainage, and can drain water in the pit through siphon action when the pit (locally sunken into the pit range of 10m) is formed on the road base surface.

The transverse drainage type composite geomembrane provided by the invention can be integrally produced in a factory, the production process is simple, convenient and feasible, the site construction procedures and the construction difficulty are reduced, and the popularization and the application are convenient. The invention can effectively solve the problem of water drainage of the roadbed body.

The material used for the transverse drainage type composite geomembrane is made of a material with pressure resistance, corrosion resistance and high strength, so that the composite geomembrane has strong deformability and high fatigue resistance, and the drainage and seepage prevention effects and the durability of use are ensured.

The features mentioned above can be combined in various suitable ways or replaced by equivalent features as long as the object of the invention is achieved.

Drawings

The invention will be described in more detail hereinafter on the basis of non-limiting examples only and with reference to the accompanying drawings. Wherein:

fig. 1 is a schematic structural view of a conventional geomembrane;

fig. 2 is a schematic structural view of a transverse drainage type composite geomembrane according to an embodiment of the present invention;

FIG. 3 is an enlarged view taken at A in FIG. 2;

FIG. 4 is a schematic view of a portion of a capillary drainage strip in accordance with an embodiment of the invention;

fig. 5 is a schematic structural view of a transverse drainage type composite geomembrane according to another embodiment of the present invention;

fig. 6 is an enlarged view at B in fig. 5.

Description of reference numerals:

1. geotextile; 2. an impermeable layer; 3. a capillary drainage band; 4. a drainage channel; 5. a water guide slot hole; 6. a capillary groove; 7. a plastic film.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer and more complete, the following technical solutions of the present invention will be described in detail, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts based on the specific embodiments of the present invention belong to the protection scope of the present invention.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, that particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Example 1

As shown in fig. 2 and 3, the transverse drainage type composite geomembrane includes a barrier layer 2, a geotextile 1, and a plurality of drainage strips.

The impervious layer 2 is preferably a high-density polyethylene film, the thickness of the impervious layer 2 is 0.3 mm-1.5 mm, the impervious layer 2 is used as impervious material, and surface water flows along the impervious layer 2 in the downward slope direction after permeating into the roadbed and finally flows out of the roadbed body. The geotextile 1 is a non-woven geotextile 1, and is a geosynthetic material with water permeability and made of polymer fibers as raw materials; the geotextile 1 has the effects of preventing puncture, draining water and filtering soil particles. The drainage strip is preferably a capillary drainage strip made of flexible PVC material which provides a drainage channel 4 to enhance the drainage of the subgrade.

As shown in fig. 4, the capillary drainage strip 3 is a strip-shaped structure, the capillary drainage strip 3 has drainage channels 4 which extend in parallel and are densely arranged along the longitudinal direction of the capillary drainage strip, each drainage channel 4 comprises a water guide slot hole 5 which is formed in the capillary drainage strip 3 and a capillary groove 6 which is formed on the top surface of the capillary drainage strip 3 and is communicated with the water guide slot hole 5, each capillary groove 6 is a narrow gap capable of generating capillary action, and the cross-sectional area of each water guide slot hole 5 is larger than that of each capillary groove 6. The capillary action generated by the capillary groove 6 on the capillary drainage belt 3 can suck the water contained in the roadbed into the water guide slot hole 5, and the water is promoted to be sucked and collected by the siphon force generated by the water level drop section at two ends or any section of the water guide slot hole 5 to be discharged from one end of the slot hole. The capillary drainage belt 3 automatically achieves the functions of water absorption, filtration, sealing and drainage by utilizing the capillary suction effect, the siphon effect, the gravity effect and the surface tension, can effectively prevent particle blockage, enlarge the drainage range, realize negative pressure suction and active drainage, realize negative pressure generated by the surface tension and prevent water from leaking back, and the flexible design ensures that water in a pit can be drained through the siphon effect when the pit is formed on a roadbed surface.

A plurality of drainage strips are arranged on the impermeable layer 2 at intervals along the direction perpendicular to the drainage channel 4, the bottom surface of each drainage strip is fixedly connected with the top surface of the impermeable layer 2 in an adhesive mode, the bottom surface of each drainage strip is tightly attached to the top surface of the impermeable layer 2, water cannot permeate into the attaching surfaces of the drainage strips and the impermeable layer 2, and therefore the water on the impermeable layer 2 is prevented from flowing along the longitudinal direction. Two adjacent drainage belts and the impermeable layer 2 between the two drainage belts enclose to form a drainage ditch capable of directionally draining water. Capillary drainage strips 3 on two sides of the drainage ditch block surface water from permeating into the roadbed and then longitudinally move towards the roadbed along the surface of the impervious barrier 2, so that the retention time of the water in the roadbed is effectively reduced, and the roadbed maintenance is facilitated.

The assembly formed by combining the capillary drainage strips 3 and the impermeable layer 2 is bonded with the geotextile 1, so that the geotextile 1 is tightly attached to the top surfaces of the drainage strips and the top surfaces of the impermeable layers 2, and the bonded part can be positioned on the impermeable layers 2 but not on the capillary drainage strips 3, so that the bonding glue is prevented from entering the drainage channel 4, and the drainage channel 4 is prevented from being blocked and closed. The geotextile 1 covering the assembly formed by combining the capillary drainage strip 3 and the impermeable layer 2 not only has the effect of preventing the impermeable layer 2 and the top of the capillary drainage strip 3 from being pierced, but also has the effects of draining and filtering soil particles.

Specifically, the capillary drainage strip 3 is formed by forming dense water guide slots 5 on a strip-shaped structure made of soft PVC, forming water guide slots 5 with the diameter of about 1mm in the width direction of the strip-shaped structure every 1.5mm, and longitudinally splitting a capillary groove 6 with the width of about 0.3mm above each water guide slot 5, so that a drainage channel 4 with the inner part large and the outer part small and the shape like omega is formed on the cross section. The omega-shaped drainage channel 4 has the function of blocking particles from entering due to the narrow capillary groove 6, and has excellent anti-clogging performance. The width of the capillary drainage strip 3 is about 20cm, the thickness is more than 2mm, the aperture ratio is more than 20 percent, and the compressive strain strength is 6.0 MPa.

For the convenience of field construction, the width of the transverse drainage type composite geomembrane is 5-10 m, and the length is usually not less than 50 m. The top surface of the impermeable layer 2 is not adhered to the geotextile 1 at the position of 3-5 cm of the edge of each product, the structure is used as a connecting belt reserved for each product and used for connecting the webs during construction, and the impermeable layers of the connecting belts of the two products are welded together to seal the impermeable layer.

Besides adopting a gluing mode, the capillary drainage strip 3 and the impermeable layer 2 can be integrally formed together.

Example 2

On the basis of the transverse drainage type composite geomembrane provided by the embodiment 1, the geotextile 1 is additionally arranged at the bottom of the impermeable layer 2, and the geotextile 1 is tightly attached to the bottom surface of the impermeable layer 2 (see fig. 5). The geotextile 1 is additionally arranged at the bottom of the impermeable layer 2, so that the impermeable layer 2 can be prevented from being pierced from the bottom.

Example 3

The invention also provides a lateral drainage method for absorbing and collecting water in the roadbed and discharging the water out of the roadbed, the lateral drainage type composite geomembrane is laid in a roadbed basic body with a lateral gradient, a drainage ditch and a drainage channel 4 in the composite geomembrane extend along the lateral direction of the roadbed, and the drainage ditch and the drainage channel 4 drain excessive water in the roadbed basic body along the lateral direction of a line. Increase horizontal displacement through setting up the drainage zone, set up a plurality of drainage zones through the interval, utilized the drainage zone to stop water along barrier 2 to the longitudinal flow of road bed, shortened the flow distance and the flow time of water on barrier 2 surfaces, reduced the dwell time of water in the road bed to solve the not smooth problem of current road bed water drainage portion.

Finally, it should be noted that: the above embodiments and examples are only used to illustrate the technical solution of the present invention, but not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments and examples, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments or examples may still be modified, or some of the technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments or examples of the present invention.

Claims (10)

1. The transverse drainage type composite geomembrane is characterized by comprising an impermeable layer, geotextile and a plurality of drainage belts; the drainage belt is of a belt-shaped structure and is provided with drainage channels which extend in parallel in the longitudinal direction and are densely distributed, the drainage belts are distributed on the anti-seepage layer at intervals in the direction perpendicular to the drainage channels, the bottom surfaces of the drainage belts are fixedly connected with the top surface of the anti-seepage layer and are tightly attached to the top surface of the anti-seepage layer, and drainage grooves capable of draining water directionally are formed by the two adjacent drainage belts and the anti-seepage layer between the two drainage belts in a surrounding manner; the geotextile is tightly attached to the top surfaces of the drainage strips and the impermeable layer.

2. The transverse drainage type composite geomembrane according to claim 1, wherein the drainage strips are capillary drainage strips, the drainage passage comprises water guide slot holes formed in the capillary drainage strips and capillary grooves formed on the top surfaces of the capillary drainage strips and communicated with the water guide slot holes, and the cross-sectional area of the water guide slot holes is larger than that of the capillary grooves.

3. The transverse drainage type composite geomembrane according to claim 2, wherein the thickness of the capillary drainage strip is not less than 2mm, water guide groove holes with the diameter of 0.8-1.2 mm are arranged every 1-2 mm in the width direction of the capillary drainage strip, the aperture ratio is more than 20%, and the width of the capillary groove is 0.1-0.5 mm.

4. The transverse drainage type composite geomembrane according to claim 3, wherein the thickness of the capillary drainage strip is not less than 2mm, water guide groove holes with the diameter of 1mm are formed in the width direction of the capillary drainage strip every 1.5mm, and the width of the capillary groove grooves is 0.3 mm.

5. The transverse drainage type composite geomembrane according to any one of claims 1 to 4, wherein a geotextile is further arranged at the bottom of the impermeable layer, and the geotextile is tightly attached to the bottom surface of the impermeable layer.

6. The transverse drainage composite geomembrane according to any one of claims 1 to 4, wherein said drainage strip is made of a high molecular polymer.

7. The transverse drainage composite geomembrane according to any one of claims 1 to 4, wherein said geotextile is a nonwoven geotextile made of polymer fibers.

8. The transverse drainage type composite geomembrane according to claim 7, wherein the geotextile is made of polyester or polypropylene and has a thickness of 1-5 mm.

9. The transverse drainage type composite geomembrane according to any one of claims 1 to 4, wherein said barrier layer is made of high molecular polymer and has a thickness of 0.3mm to 1.5 mm.

10. A lateral drainage method for absorbing and collecting moisture in a roadbed and discharging the moisture to the outside of the roadbed, the lateral drainage method comprising the steps of: laying the lateral drainage type composite geomembrane according to any one of claims 1 to 9 in a roadbed base body having a lateral gradient, so that drainage grooves and drainage channels in the composite geomembrane extend in a lateral direction of the roadbed, and excess water in the roadbed base body is drained laterally along a route through the drainage grooves and the drainage channels.

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