CN211872410U - Waterproof and Drainage Structure of Ballastless Track Subgrade - Google Patents

Abstract

The application provides a waterproof and drainage structure for a ballastless track roadbed, the waterproof and drainage structure includes: a water collecting well, a drainage assembly and a first sealing layer, and the water collecting well is arranged in the area between the two lines of the ballastless track; The drainage assembly is arranged in the bottom layer of the subgrade of the roadbed and communicates with the water collecting well to discharge the liquid in the water collecting well from the ballastless track; the first sealing layer is arranged in the area between the lines Avoiding the surface layer of the subgrade of the water collecting well, the height of the first sealing layer is lower than the height of the support layer of the ballastless track. The waterproof and drainage structure provided by this application collects the liquid in the ballastless track and the surrounding area to the water collecting well, and discharges the liquid in the water collecting well to the outside of the ballastless track through the drainage component, so as to avoid the accumulation of liquid in the ballastless track, the drainage is rapid, and the drainage Works well.

Description

Waterproof and Drainage Structure of Ballastless Track Subgrade

technical field

The application relates to the field of geotechnical engineering, and in particular, to a waterproof and drainage structure for a ballastless track roadbed.

Background technique

Referring to FIG. 1 , the existing ballastless track 100 ′ includes a support layer 110 ′ and a track plate 120 ′ located above the support layer 110 ′. The waterproof and drainage structure of the subgrade of the ballastless track 100 ′ includes a high-enclosed waterproof and drainage structure, and the line height is closed The waterproof and drainage structure includes: a graded gravel layer 1' arranged above the foundation bed 200' in the area between the lines of the ballastless track 100' and a closed layer 2' located above the graded gravel layer 1'. The height of the closed layer 2' It is higher than the height of the track slab 120'. In this design, the water in the inter-line area is discharged laterally from the upper surface of the closed layer 2'. Due to the poor drainage effect, the normal operation of the high-speed rail is seriously affected, and the safe operation of the high-speed rail is brought about. hidden danger.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present application are expected to provide a waterproof and drainage structure for ballastless track subgrade, to solve the technical problem of poor drainage effect existing in the existing ballastless track subgrade high-enclosed waterproof and drainage structure. In order to solve the above-mentioned technical problems, The technical solutions of the embodiments of the present application are implemented as follows:

The embodiment of the present application provides a waterproof and drainage structure for a ballastless track roadbed, and the waterproof and drainage structure includes:

The water collecting well is arranged in the area between the two lines of the ballastless track;

a drainage assembly, arranged in the bottom layer of the subgrade of the roadbed, and communicated with the water collecting well, so as to discharge the liquid in the water collecting well to the ballastless track;

The first sealing layer is arranged on the subgrade surface layer of the roadbed in the inter-line area avoiding the water collecting well, and the height of the first sealing layer is lower than the height of the supporting layer of the ballastless track.

Further, the drainage assembly includes a casing and a drainage pipe sheathed in the casing.

Further, the side wall of the casing is provided with a slurry leakage hole.

Further, the drainage assembly includes a bracket disposed between the sleeve and the drainage pipe, and the bracket is used to separate the sleeve and the drainage pipe.

Further, the bracket is arranged between the sleeve and the drain pipe at intervals;

And/or, the length of the sleeve is 40cm-60cm.

Further, the waterproof and drainage structure includes a water ditch arranged in the area between the lines, and the water ditch communicates with the two adjacent water collecting wells.

Further, the water ditch has a longitudinal slope of 0.1% to 0.5%.

Further, the waterproof and drainage structure includes a second sealing layer disposed on the shoulder of the ballastless track, and the height of the second sealing layer is lower than the height of the supporting layer.

Further, the second sealing layer has a transverse slope of 3% to 6%.

Further, an end of the first sealing layer close to the support layer is higher than an end of the first sealing layer adjacent to the water ditch.

The waterproof and drainage structure of the ballastless track roadbed provided by the embodiment of the present application collects the liquid in the ballastless track and the surrounding area to the water collecting well, and discharges the liquid in the water collecting well to the outside of the ballastless track through the drainage component, so as to avoid the liquid in the ballastless track. Track accumulation, rapid drainage, good drainage effect. The first sealing layer prevents the penetration of liquids through the ground into the subgrade. Since the height of the first closed layer is lower than the height of the support layer of the ballastless track, it is convenient to find out whether there are any defects such as separation, white slurry and mud on the surface of the foundation bed at the junction of the support layer and the track slab, which is easy to control.

Description of drawings

Fig. 1 is the cross-sectional schematic diagram of the waterproof and drainage structure of ballastless track subgrade in the prior art;

2 is a schematic cross-sectional view of the waterproof and drainage structure of the ballastless track subgrade in the implementation of the application;

FIG. 3 is a cross-sectional view of the drainage assembly in the bottom layer of the bed according to the embodiment of the present application.

Reference numerals: ballastless track 100; supporting layer 110; track plate 120; subgrade bottom layer 210; subgrade surface layer 220; water collecting well 10; drainage assembly 20; casing 21; drainage pipe 22; bracket 23; first sealing layer 30; water ditch 40; second sealing layer 50; working well 300; grouting hole 400;

Detailed ways

The present application will be described in further detail below with reference to the accompanying drawings and specific embodiments. "Inter-line area" refers to the area between two lines of ballastless track, "cross slope" refers to the lateral slope of each component of the track width and road side belt of the ballastless track, and "longitudinal slope" refers to the ballastless track The longitudinal slope of the track extension direction, "up", "down" orientation or positional relationship is based on the normal use state of the ballastless track, such as the orientation or positional relationship shown in Figure 2, "cm" refers to the international unit centimeter, It should be understood that these orientation terms are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a reference to the present invention. limits.

Referring to FIG. 2 , an embodiment of the present application provides a waterproof and drainage structure for a ballastless track subgrade, including:

The water collecting well 10 is arranged in the area between the lines of the two-line ballastless track 100;

The drainage assembly 20 is arranged in the bottom layer 210 of the subgrade of the roadbed, and communicates with the water collecting well 10, so as to discharge the liquid in the water collecting well 10 out of the ballastless track 100;

The first sealing layer 30 is arranged on the subgrade surface layer 220 of the roadbed avoiding the catchment well 10 in the inter-line area.

In the prior art, the ballastless track adopts a high-enclosed drainage structure. Referring to FIG. 1 , there are frequent occurrences of mud pouring between the closed layer 2' and the track plate 120', mortar precipitation between the track plate 120' and the support layer 110', and the mortar layer (not shown). It is often difficult to find the cause of the disease after the occurrence of such diseases, so it is difficult to remediate. The reason is that the drainage of the high-enclosed drainage structure is not smooth, and the rainwater can easily enter the closed layer 2'. Since the height of the closed layer 2' is higher than the height of the track plate 120', small diseases generated in a short period of time often cannot be investigated through the line. It was found that the closed layer 2' was seriously accumulated water. Under the shock and vibration of the high-speed load of the train, mud was gradually formed between the closed layer 2' and the track plate 120', and the mortar was precipitated between the track plate 120' and the support layer 110'. Serious diseases such as layer damage and separation, on the other hand, because the height of the sealing layer 2' is too high, it is not easy to remediate the above-mentioned diseases.

In the ballastless track subgrade waterproof and drainage structure provided by the embodiment of the present application, the subgrade includes a subgrade surface layer 220 and a subgrade bed bottom layer 210, and the subgrade bed surface layer 220 bears a large dynamic stress generated by the train load, and the drainage assembly 20 is arranged on the subgrade bed bottom layer. 210 is beneficial for maintaining the structural stability of the drainage assembly 20 and also for maintaining the structural stability of the roadbed. In addition, in some embodiments, the subgrade surface layer 220 includes graded crushed stone. In this case, since the graded crushed stone has greater strength, disposing the drainage assembly 20 on the base bed bottom layer 210 can prevent damage to the subgrade. On the basis of the original ballastless track 100, the drainage assembly 20 is quickly installed into the bottom layer 210 of the foundation bed, which is convenient for construction. The liquid in the ballastless track 100 and the surrounding area is collected to the water collecting well 10, and the liquid in the water collecting well 10 is discharged out of the ballastless track 100 through the drainage assembly 20, so as to avoid the accumulation of liquid in the ballastless track 100, and the drainage is rapid and effective. it is good. The first sealing layer 30 prevents liquid from infiltrating the roadbed through the ground surface, thereby avoiding serious diseases such as mud churn between the first sealing layer 30 and the track plate 120, mortar precipitation between the track plate 120 and the support layer 110, mortar layer damage and separation. On the other hand, since the height of the first sealing layer 30 is lower than the height of the support layer 110 of the ballastless track 100, it is convenient to find out in time whether there is a seam, white slurry, and the surface layer of the foundation bed at the junction of the support layer 110 and the track slab 120. Diseases such as muddy water are easy to treat. It can be understood that the caulking between the first sealing layer 30 and the supporting layer 110 needs to be sealed to prevent the caulking between the first sealing layer 30 and the supporting layer 110 from penetrating into liquid.

If the waterproof and drainage structure of the ballastless track roadbed provided in the embodiment of the present application is installed on the existing ballastless track, the closed layer and graded gravel layer in the area between the lines can be removed by using an electric pick or an air pick equipped with an air compressor. , For the thicker part of the closed layer, a cutting machine can be used to cut the thicker part into pieces and then transport it out of the line by a flatbed truck or a trolley. Of course, if the waterproof and drainage structure of the ballastless track subgrade provided in the embodiment of the present application is provided on the newly constructed ballastless track, the following construction steps can be directly implemented without this step.

Next, referring to FIG. 2 , a work well 300 is excavated in the area between the lines to facilitate subsequent construction operations. The drainage assembly 20 is laterally pushed into the subgrade bottom 210 of the roadbed. Specifically, the drainage assembly 20 is laterally pushed into the subgrade 210 from the working well 300 by using a micro pipe jacking device. The assembly 20 is pushed into the base bed 210 from the side of the base bed 210 away from the area between the lines; next, the gap around the drainage assembly 20 is filled, on the one hand, to prevent the gap around the drainage assembly 20 from becoming a circulation channel for groundwater and other liquids, On the other hand, it plays the role of stabilizing the drainage assembly 20 .

Next, a water collecting well 10 is set in the working well 300. The water collecting well 10 can be cast-in-place using a formwork containing steel bars, or it can be prefabricated in advance. Using the prefabricated water collecting well 10 can save construction time. The communication between the drainage assembly 20 and the water collecting well 10 may be a water outlet hole (not shown) that communicates with the drainage assembly 20 is reserved during the manufacturing process of the water collecting well 10, or a water outlet can be opened on the water collecting well 10 after the water collecting well 10 is fabricated. The liquid in the water collecting well 10 is discharged from the drainage assembly 20 to the ballastless track 100 through the water outlet hole, so as to avoid the liquid volume remaining on the ballastless track 100 and affecting the safety of the ballastless track 100 .

Thirdly, the first sealing layer 30 is formed by pouring concrete on the subgrade surface layer 220 of the roadbed avoiding the catchment well 10 in the area between the lines. The height of the first sealing layer 30 is lower than the height of the support layer 110 of the ballastless track 100 , so that the liquid in the ballastless track 100 is collected to the water collecting well 10 and discharged through the water collecting well 10 . Specifically, the first sealing layer 30 is formed by pouring fiber concrete.

Finally, sealing the caulking between the first sealing layer 30 and the supporting layer 110 includes: cleaning the caulking between the first sealing layer 30 and the supporting layer 110 , sticking antifouling tape on the adjacent area around the caulking, and of course It is not necessary to use the antifouling tape. The antifouling tape is used to prevent the interface agent and sealing material from contaminating the adjacent area around the junction. The interface agent is painted on the surface of the caulking. Of course, the interface agent can also be used without the interface agent. The interface agent is used to improve the surface of the junction performance, so that the sealing material can better achieve the sealing effect, fill the caulking with filler, and the filler is a material with waterproof sealing effect, such as silicone sealant or polyurethane sealant, to prevent liquid from entering the first sealing layer 30 from the caulking , the support layer 110 and/or the roadbed, remove the antifouling tape.

The construction method of the waterproof and drainage junction for forming the ballastless track subgrade of the embodiment of the present application through the above construction steps is simple, the construction efficiency is high, and the construction period is short, which is convenient to complete the construction within the skylight period.

In an embodiment of the present application, please refer to FIG. 3 , the drainage assembly 20 includes a casing 21 and a drainage pipe 22 sheathed in the casing 21 . With this structure, the casing 21 is used to withstand the earth pressure, water pressure and road load from the subgrade, and maintain the structural rigidity of the drainage assembly 20 . A drain pipe 22 for draining water is sheathed in the casing 21, so that the drain assembly 20 has a longer service life. If the method of pushing the drainage assembly 20 laterally into the bottom layer 210 of the foundation bed is adopted, and the structure of the casing 21 and the drainage pipe 22 sheathed in the casing 21 is adopted, the casing 21 with stronger force capacity can be pushed first. into the bottom layer 210 of the foundation bed, and then a drain pipe 22 is arranged in the casing 21 . In a specific embodiment, in a specific embodiment, the sleeve 21 can be a metal pipe, such as galvanized steel pipe, copper pipe, etc., which has strong structural strength, which is not only convenient for bearing compressive stress and bending moment, but also convenient for The cover 21 is laterally pushed into the bottom layer 210 of the base bed. The drain pipe 22 can be an organic polymer pipe such as a polyvinyl chloride pipe, a polyethylene pipe, and a high-density polyethylene pipe. The above-mentioned structure is cheap to manufacture and has a long service life.

In an embodiment of the present application, please refer to FIG. 3 , a slurry leakage hole (not shown) is formed on the side wall of the sleeve 21 . The drainage assembly 20 is arranged in the subgrade bottom layer 210 of the roadbed. Due to the need to seal and fill the gap around the drainage assembly 20, a slurry leakage hole is opened on the side wall of the casing 21 to facilitate filling the subgrade bottom layer 210 and the casing 21, The gap between the casing 21 and the drain pipe 22. During the construction process of filling the slurry, the slurry seals and fills the gap around the drainage component 20 through the slurry leakage hole. This design reduces the grouting process and saves the construction period.

In an embodiment of the present application, please refer to FIG. 3 , the drainage assembly includes a bracket 23 disposed between the casing 21 and the drainage pipe 22 , and the bracket 23 is used to separate the casing 21 and the drainage pipe 22 . This design prevents the inner wall of the sleeve 21 and the outer wall of the drain pipe 22 from abutting together and affecting the filling of the gap between the sleeve 21 and the drain pipe 22 .

During the construction process of filling the gap around the drainage assembly 20, since the bracket 23 is arranged between the casing 21 and the drainage pipe 22, the casing 21 and the drainage pipe 22 are separated, and therefore, the inner wall of the casing 21 and the drainage pipe 22 are avoided. The fit of the outer walls of the pipes 22 together affects the filling of the gap between the sleeve 21 and the drain pipe 22 . In the specific implementation steps, the gap between the end of the casing 21 and the base layer 210 is blocked to form a first sealing layer, and the gap between the end of the drain pipe 22 and the end of the casing 21 is blocked to form a second sealing layer. In the plugging layer, a grouting hole 400 and an exhaust hole 500 are opened on the first plugging layer or the second plugging layer, and a high-pressure grouting pump is used to inject slurry from the grouting hole 400. The slurry hole, the slurry enters the gap between the drainage pipe 22 and the casing 21, the gap between the casing 21 and the base layer 210 along the slurry leakage hole, and the gas or liquid in the gap around the drainage assembly 20 is discharged from the exhaust gas. The hole 500 is discharged, and the slurry gradually fills the gap around the drainage assembly 20 from the slurry leakage hole until the slurry completely fills the gap around the drainage assembly 20, and the grouting is stopped. Of course, after the grouting is completed, the grouting hole 400 and the exhaust hole 500 need to be blocked. On the one hand, the grouting hole 400 and the exhaust hole 500 are prevented from becoming the circulation channel of groundwater, and on the other hand, the liquid from the outside is prevented from passing through the grouting hole. 400 and the exhaust hole 500 enter into the roadbed. It can be understood that, if the gap around the drainage assembly 20 is not full of grouting, multiple grouting holes 400 and exhaust holes 500 can be opened, and multiple grouting holes 400 or exhaust holes 500 can be opened. On the first plugging layer, both can be set on the second plugging layer, or can be set on the first plugging layer and the second plugging layer at the same time.

In an embodiment, please refer to FIG. 2 , in order to further facilitate grouting, a grouting hole 400 can also be opened on the subgrade surface layer 220 or the ballastless track 100 , and one end of the grouting hole 400 extends to the casing 21 and the subgrade. In the gap between the bottom layers 210, grouting is performed from the other end of the grouting hole 400 using a high-pressure grouting pump, and the slurry gradually fills the gap between the casing 21 and the bottom layer 210 of the base bed, and then passes through the grouting hole to gradually fill the casing. 21 and the gap between the drain pipe 22.

In an embodiment of the present application, please refer to FIG. 3 , the brackets 23 are disposed between the sleeve 21 and the drain pipe 22 at intervals. Disposing the brackets 23 at intervals can better separate the casing 21 and the drain pipe 22 , and is also convenient to reduce the volume of the bracket 23 , and is convenient to be arranged between the casing 21 and the drainage pipe 22 . Specifically, the distance between two adjacent brackets 23 is 15 cm˜30 cm. In this design, fewer brackets 23 are used to ensure better separation between the casing 21 and the drain pipe 22, thereby saving costs.

In order to further facilitate construction on a ballastless track with a relatively narrow space, in an embodiment of the present application, please refer to FIG. 3 , the length of the sleeve 21 is 40cm-60cm. For example, 40cm, 45cm, 50cm, 55cm, 60cm. It can be understood that a plurality of sleeves 21 can be combined to form a pipeline whose length meets the requirement of the drainage distance. Exemplarily, a plurality of sleeves 21 may be connected back and forth to form a long drainage pipeline, and the connection between the multiple sleeves 21 may be welded or screwed or connected by joints. In a specific embodiment, two adjacent sleeves 21 are welded. This design facilitates sealing the seam between the sleeves 21 and prevents water from seeping out at the seam between the two sleeves 21 . In another specific embodiment, two adjacent sleeves 21 are screwed together. It not only facilitates the positioning and connection between the two sleeves 21 , but also facilitates improving the sealing performance between the two sleeves 21 . Specifically, one end of the sleeve 21 may have an external thread, and the opposite end may have a matching internal thread. It can also be that the sleeve 21 includes a first sleeve (not shown) and a second sleeve, both ends of the first sleeve have internal threads, and both ends of the second sleeve have internal threads adapted to the first sleeve. External thread, the first sleeve is screwed with the second sleeve. In yet another specific embodiment, two adjacent sleeves 21 are connected by a joint. This design is convenient to further improve the sealing performance between the two sleeves 21 . Specifically, the joint may be an internal threaded joint or an external threaded joint or a clamp.

In an embodiment of the present application, please refer to FIG. 2 , the waterproof and drainage structure includes a water ditch 40 disposed in the area between the lines, and the water ditch 40 is connected to two adjacent water collecting wells 10 . The water ditch 40 is connected to the two adjacent water collecting wells 10 , so that the liquid in the area between the lines can enter the water collecting well 10 through the water ditch 40 , so as to discharge the ballastless track 100 through the drainage assembly 20 .

In an embodiment of the present application, please refer to FIG. 2 , the water ditch 40 is an open ditch, that is, the water ditch 40 is disposed above the subgrade surface in the inter-line area, and the water ditch 40 connects two adjacent water collecting wells 10 . The water ditch 40 is used for draining the liquid on the surface of the area between the lines, and draining the liquid on the surface of the area between the lines to the water collecting well 10 . When the water ditch 40 is an open ditch, in order to quickly set the water ditch in the embodiment of the present application in the area between the lines, the water ditch in the embodiment of the present application may be set during the construction process of setting the first sealing layer 30 . When the first closed layer 30 is formed, a ditch formwork is placed. The ditch formwork can use a pipe with a set radius, and the pipe can be fixed by a withholding connector, and then the area between the lines avoids pouring concrete on the surface layer 220 of the foundation bed of the water collecting well 10 The first sealing layer 30 is formed, and after the construction of the first sealing layer 30 is completed, the water ditch formwork is removed to form the water ditch 40 . The water ditch 40 is connected to the two adjacent water collecting wells 10 , so that the liquid in the area between the lines can enter the water collecting well 10 through the water ditch 40 , so as to discharge the ballastless track 100 through the drainage assembly 20 .

In another embodiment of the present application, the water ditch 40 is an underdrain, that is, the water ditch 40 is buried in the surface layer of the subgrade in the area between the lines, and the water ditch 40 is connected to two adjacent water collecting wells 10 . The water ditch 40 is an underdrain used for draining the liquid in the surface layer of the subgrade in the area between the lines, and draining the liquid in the surface layer of the subgrade in the area between the lines to the water collecting well 10 .

In order to facilitate the liquid in the water ditch 40 to enter the water collecting well 10 , in an embodiment of the present application, please refer to FIG. 2 , the water ditch 40 has a longitudinal slope of 0.1% to 0.5%.

In an embodiment of the present application, please refer to FIG. 2 , the waterproof and drainage structure includes a second sealing layer 50 disposed on the shoulder of the ballastless track 100 , and the height of the second sealing layer 50 is lower than that of the supporting layer 110 . Such a structure facilitates the discharge of the liquid collected on the shoulder of the ballastless track 100 from the upper surface of the second sealing layer 50 to the ballastless track 100 .

If the second sealing layer 50 is set on the shoulder of the existing ballastless track, the shoulder graded gravel layer of the existing ballastless track and the shoulder sealing layer located above the shoulder graded gravel layer need to be chiseled. Use electric picks or air-compressor supporting air picks to chisel off the shoulder graded gravel layer and the road shoulder sealing layer. Carts are transported out of line. Of course, if the second sealing layer 50 is provided on the shoulder of the newly constructed ballastless track, the second sealing layer 50 may be directly provided on the shoulder without this step. The second sealing layer 50 can also be formed by pouring fiber concrete.

In order to further facilitate the discharge of the liquid collected on the shoulder of the ballastless track 100 from the upper surface of the second sealing layer 50 to the ballastless track 100, in an embodiment of the present application, please refer to FIG. 2, the second sealing layer 50 is 3%-6% of the slope.

In order to facilitate the liquid on the first sealing layer 30 to quickly enter the water collecting well 10 and/or the water ditch 40, in an embodiment of the present application, please refer to FIG. 2, the end of the first sealing layer 30 close to the supporting layer 110 is higher than the first sealing layer 30 Layer 30 is near one end of gutter 40 . Further, the gradient between the end of the first sealing layer 30 close to the support layer 110 and the end of the first sealing layer 30 close to the water ditch 40 is 3%-6%.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. Covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims (10)

1. The utility model provides a drainage structures of ballastless track road bed which characterized in that, drainage structures includes:

the water collecting well is arranged in an inter-line area of the two ballastless tracks;

the drainage assembly is arranged in the bed bottom layer of the roadbed and communicated with the water collecting well so as to discharge liquid in the water collecting well out of the ballastless track;

the first sealing layer is arranged on the surface layer of the foundation bed of the roadbed, avoiding the water collecting well in the inter-line area, and the height of the first sealing layer is lower than that of the supporting layer of the ballastless track.

2. The water repellant structure of claim 1, wherein the drain assembly includes a sleeve and a drain tube nested within the sleeve.

3. The waterproof and drainage structure as claimed in claim 2, wherein the side wall of the sleeve is provided with a slurry leakage hole.

4. The drain prevention structure of claim 2 wherein the drain assembly comprises a bracket disposed between the sleeve and the drain pipe, the bracket for spacing the sleeve from the drain pipe.

5. The drain prevention structure of claim 4 wherein the bracket is spaced between the sleeve and the drain pipe;

and/or the length of the sleeve is 40 cm-60 cm.

6. The structure of any one of claims 1 to 5, wherein the structure includes gutters disposed in the inter-line region, the gutters communicating with two adjacent water collection wells.

7. The waterproof and drainage structure of claim 6, wherein the gutter is a longitudinal slope of 0.1% to 0.5%.

8. The waterproof and drainage structure as claimed in any one of claims 1 to 5, wherein the waterproof and drainage structure comprises a second sealing layer arranged on the ballastless track shoulder, and the height of the second sealing layer is lower than that of the supporting layer.

9. The waterproof and drainage structure of claim 8, wherein the second sealing layer has a cross slope of 3% to 6%.

10. The drain-resistant structure of claim 6 wherein the end of the first closure layer adjacent the support layer is higher than the end of the first closure layer adjacent the gutter.

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