JP2006125166A - Banking technique utilizing foam glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effective suppress landslide or caving of a bank by use of foam glass having characteristics of light weight and high permeability in a method and construction structure for preventing landslide or caving in a natural slope or a bank part. <P>SOLUTION: A dent or hole of an optional shape having an optional depth is dug in an area possibly causing landslide or caving of a slope, and stuffed with a foam glass material, so that a level rise of ground water can be suppressed. The foam glass material stuffed part is provided in a plurality of positions, and the respective foam glass material stuffed part are allowed to communicate with each other or with outside air through a permeable passage, whereby the draining of each foam glass stuffed part is promoted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method and a construction structure for preventing the occurrence of landslide and collapse in natural sloped land and embankment.

Along with the increasing momentum of the zero emission (resource recycling society) concept aimed at preserving the global environment, recycled products that reuse various types of waste have been devised. One such product is foamed glass, a new material that is processed and reused from waste glass. Foamed glass is an indeterminate block of 2 to 75 mm, and has light weight and high water flow characteristics. Although it has begun to be used as a substitute for sand and gravel, such as retaining walls that are civil engineering structures and box culverts, etc., the number of adoption has not increased due to high costs. It is necessary to establish a utilization method that fully utilizes the characteristics of foam glass.

On the other hand, many embankment slopes are being constructed with the development of residential land, farmland, parks, and the like. For example, a lightweight embankment method described in Japanese Patent Application Laid-Open No. 2001-193071 is also disclosed. The slope gradient at the time of embankment is determined according to the strength of the embankment material, but if it is necessary to make the slope steeper than the stable slope due to land use, reinforcement by the retaining wall or embankment The slope is stabilized by reducing the weight of the material. However, landslides and collapses often occur on embankment slopes after heavy or long rains. One of the main factors for the occurrence of such landslides and collapse is the increase in pore water pressure accompanying the rise in groundwater level, and countermeasures are usually taken by removing groundwater by draining boring. Excluding groundwater is effective not only for embankment but also for preventing landslides that have occurred on natural slopes. However, there is a problem that the perforated pipe for drainage of drainage boring works over time.
JP2001-1993071

In this invention, the design of the embankment slope using foamed glass was examined using the embankment slip example that occurred due to heavy rain as a model.

FIG. 1 is a cross-sectional view showing a normal created embankment slope. In the construction and development of farmland, residential land, parks, etc. in sloped areas, the embankment slopes as shown in Fig. 1 are required for the structure. The slope length often increases depending on the ground and soil properties, and it is necessary to reinforce the slope with a retaining wall as a short steep slope due to the acquisition of new land and the use of the surrounding land. Increase. On the other hand, in the soil where there are many soil problems, the soil near the boundary between the embankment and the former ground is weakened year after year by the seepage water.

On the other hand, the foam glass used in the present invention is produced as follows. That is, 1 in FIG. 2 (1) is waste, and when this waste bottle 1 is crushed by a crusher, it becomes a grain 2 having a size of several mm as shown in (2). When this glass cullet 2 is pulverized into powder by a pulverizer, it becomes glass powder 3 as shown in (3). When a foaming agent is mixed with such glass powder 3 and fired in a furnace, it comes out as a plate-shaped foaming board, but when it is rapidly cooled in the atmosphere, it spontaneously breaks and pumice like (4) The resulting foamed glass 4 is obtained. Details of the apparatus for producing foam glass are disclosed in JP-A-2001-335391.

Thus, the foam glass used in the present invention is a new material that reuses glass such as waste glass bottles. The characteristics of the finished foam glass are continuous porous (water-absorbing) or independent porous (non-water-absorbing) glassy porous materials, and the drying density and water absorption can be adjusted by changing various conditions in the manufacturing process. it can. The foam glass used in the present invention is of the independent gap type having a dry density ρd = 0.4 to 0.5 g / cm ³ and a water absorption of 10%. <The unit volume weight of the 37.5 mm adjusted sample is νw = 2.9 to 3.9 kN / m ³ , and the water permeability is κ = 3 × 10 −2 to 1 × 10 0 cm / s.

The technical problem of the present invention is to pay attention to the above-mentioned problems in conventional embankment, and to effectively suppress landslides and collapses such as embankments using a lightweight and highly water-permeable foam glass. is there.

The technical problem of the present invention is solved by the following means. Claim 1 can dig a hollow or hole of an arbitrary shape at an arbitrary depth in an area that is likely to cause landslides or collapse of an inclined surface, and can be filled with foamed glass material to suppress an increase in the level of groundwater. It is a landslide control method using foamed glass characterized by the following. The inclined surface includes not only the inclined surface of the embankment but also a naturally formed inclined surface. In this way, according to the method of digging a hollow or hole of an arbitrary shape of an arbitrary depth in an area that is likely to cause landslide or collapse of an inclined surface, and filling the foam glass material into it, the surrounding groundwater is Concentrate on the foam glass material stuffing section. As a result, even if the water collected in the foam glass material stuffing part can be effectively drained, the water level of the groundwater can be prevented from becoming higher than the bottom of the foam glass material stuffing part, and the water level of the groundwater is lowered than before. it can. Therefore, it is possible to effectively suppress the landslide and collapse of the inclined surface due to the lowering of the groundwater level. In order to effectively drain the water collected in the foam glass material stuffing section, it can be realized by searching for a place where natural water permeability is good and providing it in the vicinity or communicating through a water passage.

According to a second aspect of the present invention, there is provided the landslide suppressing method using the foamed glass according to the first aspect, wherein the foamed glass material stuffing portion is provided at a position near the inclined surface on the forming surface. When there is a creation surface on an inclined surface such as embankment, the position near the inclined surface on the creation surface tends to cause landslide and collapse. In addition to the effect of lowering the water level of groundwater, providing the above-mentioned foam glass material stuffing part in the area where landslides and collapse are likely to occur in this way, in addition to the effect of lowering the level of groundwater, landslides and collapses occur even more It becomes difficult to do.

Claim 3 is the landslide suppression method using foamed glass according to claim 1 or 2, wherein the foamed glass material stuffing portion is disposed along a contour part on the inclined surface. is there. As described above, the foam glass material stuffing portion is disposed along the contoured portion on the inclined surface, so that the water level of the groundwater can be made uniform on the whole. Therefore, it is possible to prevent a problem in which a part where the groundwater level is particularly low and a landslide or collapse occurs from that part.

According to a fourth aspect of the present invention, the foamed glass material stuffing portion is provided at a plurality of locations, and communicated between the respective foamed glass material stuffed portions or outside air through a water passage. A landslide suppressing method using the foamed glass according to claim 3. The water-permeable path may be a pipe or a drainage path, or may be a water-permeable path filled with soil having good water permeability or foamed glass used in the present invention. As described above, the foam glass material stuffing portion is provided at a plurality of locations, and the foam glass material stuffing portion is communicated with each other through the water passage so that the lowest foaming from the highest foam glass material stuffing portion. After collecting the wastewater in the glass material stuffing section, it can be led to the atmosphere and drained to the outside. Or you may make it communicate with external air by a water flow path from several each foam glass material stuffing part, and may drain outside.

According to the method of digging a hollow or hole of an arbitrary shape of an arbitrary depth in an area that is likely to cause a landslide or collapse of an inclined surface as in claim 1, Of groundwater concentrates in the foam glass material stuffing section. As a result, even if the water collected in the foam glass material stuffing part can be effectively drained, the water level of the groundwater can be prevented from becoming higher than the bottom of the foam glass material stuffing part, and the water level of the groundwater is lowered than before. it can. Therefore, it is possible to effectively suppress the landslide and collapse of the inclined surface due to the lowering of the groundwater level.

In addition to the effect of lowering the level of groundwater, the foamed glass material stuffing portion is provided in a region that is prone to landslide or collapse, such as the position near the inclined surface on the creation surface, in addition to the effect of lowering the level of groundwater. Since the glass material is light, landslides and collapses are even less likely to occur.

According to the third aspect of the present invention, the foam glass material stuffing portion is disposed along the contoured portion on the inclined surface, so that the groundwater level can be made uniform on the whole. Therefore, it is possible to prevent a problem in which a part where the groundwater level is particularly low and a landslide or collapse occurs from that part.

As in claim 4, the foam glass material stuffing portion is provided at a plurality of locations and communicated between each of the foam glass material stuffing portions through a water passage, so that the lowest foam glass material stuffing portion can be used. After collecting the wastewater in the foam glass material stuffing section, it can be led to the atmosphere and drained to the outside. Or you may make it communicate with external air by a water flow path from several each foam glass material stuffing part, and may drain outside.

Next, an embodiment of how the embankment technique using the foamed glass according to the present invention is practically described will be described. FIG. 3 is a longitudinal cross-sectional view of a formed embankment in which a glass foam material is appropriately applied, and FIG. 4 is a plan view thereof. 5 is a plan creation surface, 6 is an embankment inclined surface, a mesh hatched portion 7 is an embankment portion, and 8 is an original ground.

In the case of the present invention, an indentation or hole of an arbitrary shape of an arbitrary depth is dug in an area that is likely to cause a landslide or collapse of the inclined surface 6, and a foamed glass material is packed therein. It is a glass stuffing part. This foamed glass stuffing portion 9 may be provided in only one stage, but it is more effective to provide a plurality of stages as shown. As is clear from FIGS. 3 and 4, the foam glass stuffing portion 9 is disposed along the contoured portion of the inclined surface 6. Note that the lowermost foam glass filling portion 93 also serves as a terminal retaining wall.

Furthermore, taking advantage of the light weight of the foam glass, it is also effective to provide it at a position near the inclined surface 6 in the creation surface 5 like the foam glass stuffing portion 91 in FIG. Landslides and collapse of weak parts can be effectively suppressed.

FIG. 5 is a plan view showing another embodiment, in which the foamed glass stuffing portions 9 are provided at a plurality of locations, and the foamed glass stuffed portions 9 are communicated with each other through water passages 10. In the case of FIG. 5, a groove is dug between the upper and lower foam glass stuffing portions 91, 92, 93, and the foam glass is stuffed therein. Since the gap between each foam glass acts as a water passage, it acts as a drainage groove.

Although it is good also as a U-shaped groove-shaped water channel without stuffing foam glass, it is good to stuff foam glass 4 like illustration. Moreover, it is preferable that the foamed glass 4 is not exposed by covering the foamed glass 4 in the water passage 10 with the soil or the lawn as well as the foamed glass stuffing portions 9. The depth and thickness to be covered are arbitrary.

In FIG. 3, a drain pipe 11 is shown. As described above, the drainage pipe 11 may be provided on the bottom side of each of the foam glass stuffing portions 9 to connect the adjacent foam glass stuffing portions 9 so that water can be passed therethrough. The drain pipe 11 plays the role of the water passage 10 of FIG. The drain pipe 11 and the water passage 10 in FIG. 5 can be directly led to the outside air so that the water can be drained to the outside.

As described above, the foam glass stuffing portion 9 is provided, and the water collected in the foam glass stuffing portion 9 is effectively drained by using the natural drainage portion, the drain pipe 11, the water passage 10 of FIG. By adopting this method, it is possible to suppress the rise in groundwater level. The dash-dot line 12 in FIG. 3 indicates the groundwater level that has been lowered, and by providing the foam glass stuffing portion 9, the groundwater level is lowered to the vicinity of the bottom of each foamed glass stuffing portion 9. It is clear that the groundwater level shown by the two-dot chain line 13 in FIG. 1 is close to the surface of the inclined surface, which is extremely higher than that in the case of FIG.

Next, the embankment design using foam glass will be described.
1. Design using foam glass as embankment material Foam glass is highly water-permeable (κ = 3 × 10-2 to 1 × 100 cm / s), so the infiltration groundwater is discharged quickly, and the rise of the water level in the foam glass layer Absent. When the fully softened strength (φsf = 27.6 ° (csf = 0)) is applied to the strongly weathered mudstone on the virtual slip surface, and the peak strength of foamed glass (cf = 60 kN / m ² · φf = 34 °) is applied to the embankment The safety factor was Fs = 5.87. By using foam glass as the embankment material, the stability of the embankment becomes high, and it is possible to slim the end retaining wall and make the slope steep. However, large-scale use of foam glass is uneconomical, and it may be impossible to use depending on the use of the site (such as roadways and residential land where the support is required for the base).

2. Fig. 6 shows an example of embankment design utilizing the lightness of foam glass. In FIG. 6, the foam glass application portion reduces the sliding force by reducing the weight of the slide block head. Under the groundwater level shown in Fig. 6, the peak strength (cf = 60kN / m ² · φf = 34 °) is applied to the foamed glass portion of the virtual slip surface, and the peak strength (c'f = 10kN /) is applied to the embankment mudstone. When m ² · φ'f = 37.5 °) and its fully softened strength (φsf = 27.6 ° (csf = 0)) were applied to the strongly weathered mudstone, the safety factor was Fs = 1.78. The effect of reducing the weight of the sliding block head is quite large. However, since the holding effect is drastically reduced due to the light weight of the foamed glass, the back ground of the foamed glass application part is newly destabilized and may slide in a liquid state. Therefore, a new measure for preventing the occurrence of wavy slip is required.

3. Embankment design utilizing high water permeability Since the increase of pore water pressure due to the rise in groundwater level is one of the main causes of landslides, the removal of groundwater and surface water is effective in stabilizing the embankment. FIG. 7 shows an example of embankment design utilizing the high water permeability of foam glass. Foam glass was applied clearly in the hope that it would play a role in lowering the groundwater level and suppressing the rise in groundwater level. The foamed glass alum located on the upper right side of the slope functions as a water catcher and blocks the surface water and underground seepage water from the back ground, so the inflow water is excluded before penetrating the embankment slope. Under the groundwater level shown in Fig. 7, c'f = 10k N / m ² · φ'f = 37.5 ° for the strength of the embankment mudstone on the virtual slip surface, and φsf = 27.6 ° (csf = 0) was applied to obtain Fs = 1.14. By utilizing the water replenishment function of the foam glass, the same effect as the water draining boring can be expected.

4). Rational embankment design We studied the reduction of sliding force by weight reduction and the suppression of the rise of groundwater level by high water permeability. In FIG. 8, the foamed glass alum with a large slope head has a role of catching water as well as a function of reducing sliding power, and is set in consideration of not losing the pressing effect due to earth cover pressure. Those in other slopes have the function of lowering the groundwater level and suppressing the rise of the groundwater level after long and heavy rain. Even when the slope is steeply lowered (1: 1.2) and the retaining wall at the end is not installed, c'f = 10kN / m ² · φ'f = 37.5 ° is applied to the embankment mudstone of the virtual slip surface, and strongly weathered mudstone Φsf = 27.6 ° (csf = 0) was applied to the part and cf = 60 kN / m ² · φf = 34.0 ° was applied to the foamed glass part to obtain Fs = 1.52. By designing by taking advantage of the characteristics of foam glass, the embankment is reduced, the retaining wall is not required, and low-cost land preparation is possible.

As described above, the foamed glass used in the present invention is excellent in soil engineering in terms of water permeability, light weight, and strength. Therefore, according to the method of providing the foamed glass filling portion as in the present invention, it is considerably advantageous in terms of maintenance cost and safety as compared with a normal constructed embankment slope. The following points can be mentioned as the effects, effects, and advantages of applying glass foam.

(1) Water permeability of glass foam material effectively suppresses the rise of groundwater level, and light weight effectively reduces fracture stress.
(2) Since the glass foam is hardly deformed or crushed in strength, there is almost no change over time in the arrangement structure and drainage function after application.
(3) By using the advantages of (1) and (2), the slope length can be shortened by steep slope, and the cost of land acquisition can be reduced.
(4) By making the best use of the functions of (1) and (2), it is not necessary to reinforce the retaining wall at the end of the slope, and the cost of construction can be reduced.
(5) Appropriate application of glass foam to the embankment slope taking advantage of the advantages of (1) makes it possible to prevent the occurrence of landslide disasters, resulting in a structure that does not reach the critical groundwater level.
(6) It is possible to design a flexible embankment according to topography, geology, soil quality and site conditions.

As mentioned above, taking advantage of the water permeability and lightness of glass foam material, forming a non-recessed hole of any shape at any depth in an area that is likely to cause a landslide or collapse on an inclined surface. By adopting a method of stuffing foam glass inside, the water level of groundwater can be lowered, and landslides and collapse can be suppressed. Therefore, in addition to the prevention of natural disasters, it is possible to use waste glass to effectively use resources and contribute to environmental conservation by suppressing waste glass.

It is sectional drawing which shows a normal creation embankment slope. It is a figure which shows the manufacturing method of foamed glass. It is a longitudinal cross-sectional view of the creation embankment which applied the glass foam material appropriately. It is a top view of the creation embankment of FIG. It is a top view which shows embodiment which connects between the upper and lower foam glass stuffing parts. It is a longitudinal cross-sectional view which shows an example of the embankment design using the lightweight property of foam glass. It is a longitudinal cross-sectional view which shows the example of a banking design using the high water permeability of foam glass. It is a longitudinal section showing an example of rational embankment design.

Explanation of symbols

5 Planned creation surface 6 Embankment sloped surface 7 Embankment portion 8 Original ground 9 Foamed glass filling portion 91 Foamed glass filling portion 93 near the sloped surface of the created surface 93 Retaining wall 10 Water passage 11 Drainage pipe

Claims (4)

It is possible to suppress the rise of groundwater level by digging a hollow or hole of arbitrary shape at an arbitrary depth in an area that may cause landslide or collapse of an inclined surface, and filling it with foam glass material. Landslide control method using foamed glass. The landslide suppression method using foamed glass according to claim 1, wherein the foamed glass material stuffing portion is provided at a position near the inclined surface in the creation surface. The landslide suppression method using foamed glass according to claim 1 or 2, wherein the foamed glass material stuffing portion is disposed along a contoured portion on an inclined surface. 4. The foam glass material stuffing portion is provided at a plurality of locations, and communicates between each of the foam glass material stuffing portions or outside air through a water passage. Landslide control method using glass foam.

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