JPH11241342A - Soil bed strengthening construction method, and panel for strengthening soil bed - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict increase of water content of banking, and prevent deterioration of strength of banking by efficiently guiding penetrating water from an upper part of a bed to a slope face of the banking to drain it, and preventing penetration of ground water from the ground. SOLUTION: A soil bed strengthening panel 12 is buried at the lowest part or a middle part of banking 10. The soil bed strengthening panel 1 comprises a porous rigid panel 14 of curled tape members or film members with organic binder pressurized and molded to be a plate, and a waterproof sheet 16, they are laminated with each other to put the waterproof sheet 16 on the under side, and the panels are placed to position end parts of the waterproof sheets and the porous rigid panels 14 to be close to a slope face of the banking 10 to be buried in the banking. The waterproof sheet is applied to the porous rigid panel, favorably, but they may only be combined with each other. In the soil bed strengthening panel, waterproof performance may be integrally provided to one surface only of the porous rigid panel by impregnation or application.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reinforcing a roadbed formed by embankment. More specifically, an organic binder is added to a curl-shaped tape piece or a film piece at the bottom or middle of the embankment. TECHNICAL FIELD The present invention relates to a method of strengthening a soil base using a porous rigid panel formed by pressing into a plate shape, and a soil base reinforcement panel used for the method.

[0002]

2. Description of the Related Art There are various types of embankments, such as road embankments, railway embankments, and embankment embankments, and may be provided on ordinary ground or on soft ground. These embankments are generally vulnerable to rain, and embankments are reinforced to keep them stable. As the method, there is a method of providing a layer of sand or synthetic resin material at the bottom or middle part of the embankment,
Alternatively, a method of laying materials such as a nonwoven fabric, a woven fabric, and a net in an embankment is known.

Also, especially in cold regions, in order to prevent frost heaving, open large flutes at the lower ends of the embankment, put a perforated fume pipe in it, bury it with gravel, expand the gravel, and form the embankment. Structure is adopted. This is because the groundwater is guided to the perforated fume pipe and drained, thereby lowering the groundwater level and preventing the groundwater from penetrating into the embankment and freezing. In addition, there is a method of laying only a waterproof sheet as a simple method for preventing frost heave.

[0004]

However, the method of providing layers such as sand and synthetic resin material in the embankment has a problem that it is difficult to secure a sufficient earth bearing because the layers are soft.
That is, there is a possibility that a problem will occur when the vehicle passes on the embankment. Also, the method of laying materials such as nonwoven fabric, woven fabric and net has the same drawbacks as the case of providing a layer such as sand because of their softness.

The method of burying a perforated fume tube for preventing frost heave requires large-scale incidental work such as cutting a gutter, storing a perforated fume tube, and filling with gravel. In the method of laying only the waterproof sheet, the waterproof sheet is generally easily damaged, so that groundwater penetrates from the damaged portion, causing the embankment to freeze and lowering the strength. Furthermore, since a mere waterproof sheet does not have heat insulation properties, conduction of cold air cannot be prevented, and the water under the waterproof sheet freezes, pushing up the embankment and lowering the strength.

An object of the present invention is to efficiently infiltrate and drain seepage water from the upper part of the roadbed to the slope of the embankment, thereby suppressing an increase in the water content of the embankment and preventing a decrease in the strength of the embankment. The purpose is to provide a method of strengthening the soil bed. Another object of the present invention is a method of strengthening a subgrade which can prevent infiltration water from the upper part of the subgrade to the slope of the embankment and drainage, and prevent penetration of groundwater from underground, thereby preventing strength reduction due to freezing. It is to provide. Still another object of the present invention is to provide a roadbed reinforcing panel having good workability suitable for such a roadbed reinforcing method.

[0007]

According to the present invention, there is provided a porous rigidity material obtained by adding an organic binder to a curled tape piece or a curled film piece at the lowermost portion or intermediate portion of an embankment and press-molding the plate into a plate shape. The panel and the waterproof sheet are laminated so that the waterproof sheet is located below, and the waterproof sheet and the porous rigid panel are laid so that the ends of the porous panel are located near the embankment slope, and buried in the embankment. This is a method of strengthening the earthen subgrade. In the present invention, a combination of the porous rigid panel and the waterproof sheet is preferably used, and both are preferably attached to each other. Alternatively, the both may be simply overlapped. Alternatively, a configuration may be adopted in which an organic binder is added to a curled tape or film piece, and waterproofness is integrally provided only on one surface of a porous rigid panel formed by pressing in a plate shape.

The laminate of the porous rigid panel and the waterproof sheet as described above, or the earthen board reinforcing panel having waterproofness provided only on one side of the porous rigid panel, is placed at an appropriate position in the embankment. A configuration in which only the steps are provided may be employed, or particularly when the embankment height is large, the embankments may be buried in the embankment so as to form a plurality of steps at intervals in the vertical direction. In addition, the earthen board reinforcement panel is set to, for example, several% so that the side near the embankment slope is lowered.
It is effective to improve the drainage performance if provided with a degree of inclination.

As a panel for reinforcing the earthen board, an organic binder is added to a piece of curled tape or film, and the sheet is pressed and formed into a plate shape. It is preferable that a waterproof sheet is adhered to one entire surface of the porous rigid panel with an adhesive or the like. Alternatively, a configuration in which a waterproof layer is integrally formed in the vicinity of one surface of a porous rigid panel obtained by adding an organic binder to a curled tape piece or a film piece and press-molding it into a plate shape may be used.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a waterproof sheet may be laid first, and a separate porous rigid panel may be spread over the waterproof sheet, or the waterproof sheet may be provided on the back surface of the porous rigid panel as described above. It is also possible to use a soil board reinforcement panel that has been attached in advance. If the panel thickness is insufficient, a plurality of rigid panels may be laminated. In order to provide an integral waterproof layer, a waterproof material may be impregnated from the surface, or a waterproof material may be applied to the surface. Furthermore, in the manufacturing process of the porous rigid panel, the organic binder is easily collected only on one surface and the compression density of the curled tape or film piece is increased, so that one surface exhibits waterproofness. Such an inclined material (a material exhibiting the property that the waterproof performance changes in the thickness direction) may be used as a panel for strengthening the roadbed. Alternatively, when manufacturing a porous rigid panel, a configuration may be employed in which pressure molding is performed with the waterproof sheet disposed on one side, and the waterproof sheet is thermocompression-bonded.

[0011] The porous rigid panel is required in the manufacturing process.
Although a nonwoven fabric may be interposed on the contact surface of the mold, the nonwoven fabric may remain in a substantially semi-buried state. Of course, a nonwoven fabric may be attached in a later step. This non-woven fabric
When buried in the embankment, it functions as a filter that prevents fine soil particles from entering the panel and causing clogging. Therefore, the nonwoven fabric is provided on at least the surface opposite to the waterproof sheet or waterproof layer.

The curled tape or film piece is generally made of a synthetic resin, and is preferably, for example, a magnetic tape shrink piece. The magnetic tape shrinkable piece is a base film (tape) coated with magnetic powder, and has a layer structure of different materials, so that it easily curls when subjected to heat treatment. Instead of a magnetic tape piece or a magnetic film piece, a cut piece obtained by attaching a paint or the like to a synthetic resin film (tape) may be used. In addition, if a single-layer synthetic resin film or tape is strongly stirred, the temperature rises due to frictional heat or the like, and curls. Such a curled tape piece or film piece may be used. In addition to the above, a synthetic resin pipe such as a drinking water straw may be cut into an appropriate length, and the curl shape in the present invention includes a cylindrical shape.

[0013]

FIG. 1 is an explanatory view showing one embodiment of a method for reinforcing a subgrade according to the present invention. At the lowermost part of the embankment 10, a roadbed reinforcing panel 12 is laid so that its end is located near the embankment slope 10 a, and is buried in the embankment. The soil board reinforcing panel 12 used here is a waterproof sheet 16 on one entire surface of a porous rigid panel 14 which is formed by heating and pressing into a plate shape by adding an organic binder to a curled magnetic tape contraction piece. Is bonded by an adhesive. The earthen board reinforcement panel 12 is laid so that the waterproof sheet 16 faces downward, and is buried in the embankment.

The porous rigid panel 14 is specifically manufactured as follows, for example. Magnetic recording media (including waste materials) used for video tapes and cassette tapes,
A tape cut piece having a length of 20 mm or less (for example, 5 to 20 mm) is cut at 100 to 200 ° C. (preferably 140 to 17 ° C.).
(0 ° C.) to form a curled magnetic tape shrinkable piece. Next, this curled magnetic tape shrinkable piece 10
Thermosetting resin 1 as an organic binder with respect to 0 parts by weight
0 to 50 parts by weight, pressure ² to ²⁰ kgf / cm ² and temperature 1
A plate-like body exhibiting rigidity is formed by molding at a temperature of 00 to 200 ° C. The porous rigid panel 1 used here
4 has a thickness of about 10 to 50 mm, especially a thickness of 20 to 50 mm.
It is preferably about 30 mm. If the thickness is less than 10 mm, sufficient rigidity and drainage performance will not be obtained, and if it exceeds 50 mm, it will be heavy and difficult to handle. In addition, the size of the rigid panel is not particularly limited, but for example, a panel having a length of about 2 m and a width of about 1 m is preferable because it is easy to handle.

The thermosetting resin as the organic binder is, for example, one selected from a phenol resin, a urea resin, a polyester resin, a polyurethane resin, an epoxy resin, a melamine resin and the like, and is a powder or an emulsion.

Such a porous rigid panel has a large mechanical strength (bending strength or compressive strength) and a structure in which the inside has continuous voids (holes) in an in-plane direction (perpendicular to the thickness). Therefore, the water flow performance in the in-plane direction is very excellent, and the heat insulation is rich. Specifically, the bending strength is about 50kgf /
cm ² , the compressive strength is as high as about 7 kgf / cm ² , it is not easily deformed even when a large embankment load is applied, and the gap is not crushed. Also,
The permeability coefficient in the thickness direction of the porous rigid panel is 8.6.
× 10 ⁻⁴ cm / sec (approximately fine sand), and the water has a sufficiently large drainage performance to permeate in the thickness direction over the entire panel surface and then flow out in the panel surface direction. Furthermore, since it can be cut easily like plywood and has a wood screw holding power, it is extremely easy to lay it in an arbitrary shape. In addition, it has been confirmed that a rigid panel using this magnetic recording medium has excellent durability, and does not produce moss or mold even when left on the surface for several years regardless of the porosity. . This means that clogging by bacteria and the like is unlikely to occur, which is extremely convenient. One of the factors is considered to be a magnetic effect due to the inclusion of the magnetic powder. Therefore, it is very preferable to use a magnetic tape contraction piece as the tape piece.

The waterproof sheet 16 is made of a durable material such as rubber, vinyl chloride or styrene, and may be of any material and thickness as long as it does not cause breakage during installation. . Particularly, in the case of a structure in which the waterproof sheet 16 is pasted to the porous rigid panel 14 in advance, the waterproof sheet is less likely to be damaged even if it is somewhat thin.

In the soil bed constructed in this way, the permeated water from the upper part of the bed is infiltrated into the porous rigid panel 14 and taken in, flows inward in the inner surface thereof, and is guided to the side groove 18 of the embankment 10. Drained. Further, since penetration of groundwater from underground is blocked by the waterproof sheet 16 on the lower surface, a decrease in the strength of the embankment due to an increase in the water content of the embankment is prevented, and sufficient strength can be maintained. Since the porous rigid panel 14 has sufficient rigidity, the deformation of the embankment is suppressed, and a sufficient earth bearing capacity is also exhibited. In addition, since the porous rigid panel 14 has good heat insulating properties, it can also prevent conduction of cold air and prevent freezing of the embankment in construction in a cold region or the like.

FIG. 2 to FIG. 4 are explanatory views showing several other embodiments of the method of strengthening the soil bed according to the present invention. Since the basic configuration is the same as that of FIG. 1, corresponding portions are denoted by the same reference numerals for simplification of description. As shown in FIG. 2, a method of embedding the earthen board reinforcement panel 12 in the middle part of the embankment 10 may be used. When the main purpose is to prevent frost heaving, as shown in FIG. 3, side grooves 18 are provided on both sides, and the roadbed reinforcing panel 12 is embedded in the lowermost portion of the embankment 10. When the embankment height is large, as shown in FIG. 4, the embankment can be reinforced by embedding the earthen board reinforcement panels 12 in a plurality of steps at intervals in the vertical direction. When buried in a plurality of levels, a waterproof sheet or a waterproof layer may not be provided for upper steps except the lowest step. In these methods, in order to further improve the drainage performance, there is a method of laying the roadbed reinforcement panel at an angle of several degrees (for example, about 3 degrees) so as to become lower toward the embankment slope. .

In these embodiments, unless the main purpose is to prevent frost heave, the panel for strengthening the earthen bed does not necessarily need to be laid on the entire surface of the embankment, but may be laid only around the embankment slope. . The end face of the earthen board reinforcement panel may protrude from the embankment slope. When burying a roadbed reinforcement panel in the middle of the embankment, some kind of flow treatment is applied to the embankment slope. For example, installing a gutter or covering it with sprayed concrete and draining it.

The connection between the subgrade panels may be performed by any conventionally known method. For example, as shown in FIG.
The earthen board reinforcement panel 12 may be connected to the connecting member 22 having the H-shaped cross section having the hole 20 by being fitted thereto,
As shown in FIG. 5B, a method may be used in which a plastic plate 24 is applied to the upper and lower sides and fastened with a fixing tool 26 such as a bolt. In addition, although not shown in the drawings, there are a method of connecting the members continuously using a member having a T-shaped cross section, or a method of processing a step or the like at the end of the panel and combining them. More simply, the upper and lower surfaces of adjacent panel edges may be joined by an adhesive tape, or, in some cases, may be simply arranged. Alternatively, there is a method in which rigid panels having a thickness of about half of the required thickness are stacked with their joining positions shifted vertically. In any case, any arrangement may be used as long as the arrangement does not impede the drainage performance of the adjacent roadbed reinforcement panels in the in-plane direction and can maintain the mutual positional relationship.

The present invention is also effective for the treatment of tunnel residual soil, etc., and the earthen bed mentioned in the present invention includes an embankment treated with tunnel residuals. Excavated soil from the tunnel is buried in a valley or the like by using natural terrain. If the remaining soil of the tunnel is particularly shirasu, it is necessary to prevent the accumulation of water on the embankment (deposited shirasu). This is because if the rainwater that has infiltrated the deposited shirasu accumulates, it may flow like quicksand and collapse. In such a case, for example, as shown in FIG.
The siding 30 is made of concrete and the remaining soil 32 is buried. Then, when an appropriate thickness is deposited, the roadbed reinforcing panels 12 are laid, and the tunnel remaining soil 32 is piled up thereon. Panel 12 for earthen board reinforcement
Of course, it may be spread over the entire surface, but it is provided at least in the vicinity of the step. Reference numeral 18 denotes a side groove. The upper and lower intervals (thickness of the shirasu deposition layer) and the burying range, etc., in which the soil reinforced panel is buried are appropriately set according to the construction state. Even if the rainwater penetrates, when it reaches the earthen board reinforcing panel 12, it penetrates into the inside and is guided in the in-plane direction, and is efficiently drained to the outside. Can be prevented and a stable subgrade can be formed. Needless to say, the slope surface is subjected to a powder treatment.

The present invention is also effective when embanking on soft ground. For example, this is a case where an athletic field or a park is constructed on soft ground such as a peat layer. Spread the soil-strengthening panels on the soft ground and lay embankment on it. The load of the embankment and the like is supported in a planar manner by the roadbed reinforcement panel, and penetrating rainwater is drained through the roadbed reinforcement panel. When the moisture in the soft ground escapes due to the load of the embankment, the ground subsidence occurs.However, in the method of the present invention, the moisture in the soft ground is supported on average by the soil-strengthening panel even when the load is applied and the waterproof sheet or the waterproof layer reduces the moisture in the soft ground. Since penetration into the upper embankment is prevented, settlement of soft ground can be prevented.

In the manufacturing process of the porous rigid panel used for the soil-base reinforcement panel, a non-woven fabric (for example, a PET non-woven fabric) may be interposed between the pressing dies located on both surfaces during the pressure molding. Because of this, the whole or a part of the nonwoven fabric may remain partially buried on both the front and back surfaces of the porous rigid panel. Even in that case, a waterproof sheet may be adhered to one surface of the non-woven fabric while leaving the non-woven fabric. Also,
As shown in FIG. 5, the waterproof layer 22 can be formed by impregnating a waterproof material from the surface of the porous rigid panel 14, as shown in FIG. As a waterproof material to be impregnated, for example, an epoxy resin can be used. Of course, a waterproof layer may be formed by applying a waterproof material to the surface of the porous rigid panel. As a waterproof material to be applied, for example, urethane resin, epoxy resin, rubber, or the like can be used. Even in those cases, a nonwoven fabric may be provided on the surface opposite to the waterproof layer. These nonwoven fabrics function as a filter for preventing soil particles from entering, and also function to protect and strengthen the surface of the porous rigid panel.

Alternatively, in the process of manufacturing a porous rigid panel, the organic binder is easily collected only on one surface and the compression density of the curled magnetic tape shrinkable piece is increased, so that one surface exhibits waterproofness. Such an inclined material (a material exhibiting the property that the waterproof performance changes in the thickness direction) may be used as a panel for strengthening the roadbed. This is based on the fact that the surface side is easily compressed and dense at the time of pressure molding. For example, if a manufacturing method is adopted in which two sheets are stacked with a nonwoven fabric or the like interposed therebetween and pressure molded at the same time, only one side is used for each. And the waterproof layer can be integrally formed. As still another manufacturing method, when manufacturing a porous panel having a porous structure, it is possible to perform pressure molding while a waterproof sheet is disposed on one side, and to thermally compress the waterproof sheet. In any case, all of such a configuration can be used as the subgrade panel of the present invention.

[0026]

As described above, the present invention relates to a soil board reinforcing panel in which a porous rigid panel and a waterproof sheet are overlapped or adhered to each other or a waterproof layer is provided integrally with the porous rigid panel. Because it is a method used, simply by laying those panels for strengthening the subgrade, it is possible to efficiently drain the seepage water from the upper part of the subgrade into the gutter without constructing complicated water conveyance works, and at the same time, the infiltration of groundwater from underground And the strength of the embankment can be secured. In addition, since the heat conduction of the panel for strengthening the subgrade can prevent the conduction of cold air,
It is also possible to prevent a decrease in strength due to freezing of the embankment.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a soilbed reinforcement method according to the present invention.

FIG. 2 is an explanatory view showing another embodiment of the soilbed reinforcement method according to the present invention.

FIG. 3 is an explanatory view showing still another embodiment of the soilbed reinforcement method according to the present invention.

FIG. 4 is an explanatory view showing still another embodiment of the roadbed reinforcement method according to the present invention.

FIG. 5 is an explanatory view showing an example of a connected state of a soilbed reinforcement panel.

FIG. 6 is an explanatory view showing still another embodiment of the roadbed reinforcement method according to the present invention.

FIG. 7 is an explanatory view showing another example of a basement panel for use in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Embankment 12 Panel for reinforcing roadbed 14 Porous rigid panel 16 Waterproof sheet 22 Waterproof layer

Continuation of the front page (72) Inventor Minoru Shimokawachi 4-6-6 Kudankita, Chiyoda-ku, Tokyo Application Geological Co., Ltd. (72) Inventor Tadaaki Koyama 1-111-21 Motoren, Kawaguchi City, Saitama Prefecture Kawaguchi D (72) Inventor Kohei Takanishi 1241-1 Kishimoto-cho, Kishimoto-cho, Saihaku-gun, Tottori Fuji Chemical Industry Co., Ltd. (72) Inventor Katsuya Okada 7-16-32 Nanpei, Hino-shi, Tokyo

Claims (9)

[Claims] 1. A watertight sheet, comprising: a porous rigid panel formed by adding an organic binder to a curled tape piece or a film piece and press-forming into a plate at the lowermost portion or intermediate portion of the embankment; Laying down such that the ends of the waterproof sheet and the porous rigid panel are located near the embankment slope, and burying the embankment in the embankment. 2. A soil provided with waterproofness on only one side of a porous rigid panel formed by adding an organic binder to a curled tape piece or film piece at the lowermost portion or intermediate portion of the embankment and pressing the plate into a plate shape. A method of reinforcing a roadbed, comprising laying a basement reinforcing panel such that a surface provided with waterproofness faces downward and an end thereof is located near an embankment slope, and buried in the embankment. 3. A laminate of a porous rigid panel and a waterproof sheet, or a roadbed reinforcing panel having waterproofness provided only on one side of the porous rigid panel, and a plurality of steps at intervals in the vertical direction. The method of reinforcing a soil bed according to claim 1, wherein the soil is buried in the embankment so as to be as much as possible. 4. A laminate of a porous rigid panel and a waterproof sheet, or a roadbed reinforcing panel provided with waterproofness only near one surface of the porous rigid panel so that the side near the embankment slope is lowered. 4. The method according to claim 1, wherein the sheets are laid with an inclination.
The method of strengthening a subgrade according to any of the above. 5. The method according to claim 1, wherein the tape piece is a magnetic tape contraction piece. 6. A curable tape or film piece to which an organic binder is added and pressure-formed into a plate-like shape, and a nonwoven fabric is provided on both surfaces of the curly tape or film piece. A roadbed reinforcement panel to which a sheet is attached. 7. A waterproof layer is integrally formed on one surface or in the vicinity of one surface of a porous rigid panel formed by adding an organic binder to a curled tape piece or film piece and press-molding it into a plate shape. Panel for strengthening the earthen board. 8. The panel according to claim 7, wherein a nonwoven fabric is provided on the surface opposite to the surface on which the waterproof layer is formed. 9. The panel for strengthening a roadbed according to claim 6, wherein the tape pieces are magnetic tape shrink pieces.