JP4330504B2 - Construction method of the stable soil structure on the slope of the impervious sheet - Google Patents

Description

The present invention relates to a method for constructing a soil dressing stable structure on water shield sheet method surface, for example waste slope and that is construction as a final disposal site such as a surface impervious Engineering of shielding such as river bank protection, water pond revetment The present invention relates to a method for constructing a stable structure for a soil covering work on a slope where a water sheet is laid.

  Each drawing in FIG. 6 is a schematic cross-sectional view showing an example of a state in which the waste is fully filled in a conventional waste final disposal site. In this kind of waste disposal site 50, from the viewpoint of harmony with the surrounding environment, as shown in each drawing of FIG. The upper surface of the waste 51 is covered with an internal protective soil (not shown), and a water-impervious sheet 53 is further laid to prevent rainwater from penetrating into the storage part of the waste 51, and the water-impervious sheet 53 is formed in a predetermined layer. A type of covering with thick thick soil 55 and applying vegetation 57 and the like has been constructed. In this kind of waste final disposal site 50, as shown in each figure, a slope 56 having a predetermined gradient is formed at the end of the surface impermeable work 52 according to the embankment height. If the soil is directly laid on the water-impervious sheet 53 laid on the ground, the friction between the soil 50 and the water-impervious sheet 53 is small, so that the portion of the soil 55 may slide along the slope 56. For this reason, it is necessary to take a method for stabilizing the customer land 55 on the slope 56.

  On the other hand, as a method to stabilize the soil such as vegetation base on the slope, in order to carry out greening work such as steep slope slope, conventionally, it was unitized using a fixture such as an anchor pin A method of fixing a vegetation base block or the like to a slope has been proposed (see Patent Document 1 and Patent Document 2). In Patent Document 1, a part of a wire mesh plate is bent and a wire mesh unit having protrusions is fixed to the ground with a pin-shaped anchor material, and a vegetation material containing guest soil, seeds, etc. is sprayed on the wire mesh unit. A part is formed. Moreover, in patent document 2, a core material, such as rock wool, is fixed on the concrete layer covering the slope ground with an anchor member, and a base material is sprayed on that part to construct a horizontal beam-like base. It is designed to stabilize the land.

  In slope revegetation, it is effective to fix the vegetation base on the slope surface by anchor pins as described above, and to stabilize the soil, but on the slope where surface impermeable work has been applied, A fixing means by an anchor pin that damages the water shielding sheet cannot be taken.

  Therefore, in order to solve such problems, a water shielding sheet having a rough surface (upper surface) is laid to increase friction between the soil and the water shielding sheet, or to cover the water shielding sheet. Thus, there is a method of laying a cloth formwork, filling concrete or a vegetation base material in the cloth formwork to form a sloped surface with an uneven surface, and applying the soil to the pot-shaped recess. In addition, a greening mat that takes into account the greening of the slope at the final disposal site has been proposed (Patent Document 3). This greening mat is a unit member in which a plurality of greening base materials having a water-retaining compression base block as a core are arranged in a row on a base material made of a rectangular nonwoven fabric of a predetermined size. The slope is covered by laying so as to cover without any gaps.

Japanese Utility Model Publication No. 6-27935. JP-A-6-322770. JP 2000-120070.

  However, the greening mat disclosed in Patent Document 3 is manufactured by assembling and manufacturing a compression base block, a greening base material, a cover sheet, and the like constituting the mat at the factory, and laying them in order to be arranged individually. Therefore, the manufacturing cost is high, and correction work such as mat position adjustment is necessary, which complicates the work. In addition, when stacking the greening mats in the slope direction, it is necessary to fix and connect them using fixing means such as a tying tool. If that is insufficient, the mats stacked along the slope face May collapse. Furthermore, there is a problem that the steep slope where the mat cannot be stably installed has to be suspended and held by a wire or the like.

Therefore, the object of the present invention is to solve the above-mentioned problems of the conventional technology, and on the surface of the water shielding sheet laid on the slope, using the earthwork material that has been widely used, it is easy and safe work. and to provide a method for constructing a soil dressing stable structure on water shield sheet method surface to allow construction while stabilizing the predetermined layer thickness of the soil dressing by.

In order to achieve the above object, the present invention provides a geogrid layer by laying a geogrid along a slope covered with a water-impervious sheet as a method for constructing a stable soil structure on the slope of a water-impervious sheet. forming a, at a predetermined height of the geogrid layer, fixed on the end of the front cover of the geogrid and the same material, placed sandbags on the fixing portion of the surface cover, the lower end of the front cover A horizontal receiving beam formed by fixing the bottom end of the front cover to the geogrid layer at a position above the top of the sandbag so as to be folded upward and enclose the sandbag is covered. in the height direction at predetermined intervals and arrangement, characterized in that the upper slope surrounded by said geogrid layer and the horizontal receiving beam and covered with soil in soil dressing.

As described above, according to the present invention, to secure the front cover of the same material laid the surface of geogrid layer on slopes, the involved in horizontal receiving beam so as to cover the sandbags in the front cover Since the construction is efficient, it is possible to quickly construct a horizontal beam on the slope using normal earthwork materials, and the efficiency of the customer soil on the slope defined by the horizontal beam The soil can be well covered and the soil can be stabilized.

  Hereinafter, the present invention will be described based on examples with reference to the drawings.

  FIG. 1 is a perspective view in which a part of the slope of the surface impermeable construction of the above-described waste final disposal site (FIG. 6B) is cut away in order to explain an embodiment of the present invention.

  First, the whole structure of the slope 1 in which the surface impermeable construction 2 was constructed is demonstrated with reference to FIG. The slope 1 to which the surface impermeable work 2 (capping work) of the present embodiment is applied, as shown in the figure, with respect to the waste 3 buried with a predetermined gradient (1: 2.0). It consists of the shape which provided the small step 4 in the substantially middle position of the slope height. The surface of the raised waste 3 is covered with an internal protective soil 5 having a predetermined layer thickness, and a water shielding sheet 10 is laid on the entire slope of the internal protective soil 5. The water-impervious sheet 10 is continuously laid so as to be arranged along the lower surface of the slab-shaped small concrete 6 even at the position of the small step 4 and further covers the entire surface of the water-impervious sheet 10 and the small concrete 6 on the slope. As shown in FIG.

  FIG. 2 shows a soil covering stabilization geogrid layer 12 (hereinafter, applied to the entire slope surface) laid to cover the entire surface of the water-impervious sheet 10 in the step of performing the soil covering work (details will be described later). When referring to the entire member, it is described as “Geogrid layer 12”, and when referring to the constituent member, it is simply described as “Geogrid 13”.) It is the perspective view which showed the state of the slope in the construction stage in which the horizontal receiving beam 20 was arrange | positioned.

  As shown in FIG. 2, the geogrid layer 12 is configured such that a roll-shaped geogrid 13 having a predetermined width is laid in a belt shape in the direction of the height of the slope and covers the entire slope. In the end fixing process at the shoulder 12a (upper end) of the geogrid layer 12, the end of the geogrid 13 is extended to the fixing protrusion 6a formed in the groove shape of the small concrete 6 so as to be caught in the concrete. To fix (fix) the edges.

  In the present specification, the term “geogrid” refers to a material (member) that is formed into a net shape with a predetermined mesh by stretching a high-strength polymer sheet member perforated at a predetermined interval in a predetermined axial direction. To do. Further, in this embodiment, in the geogrid layer 12 laid on the slope 1, the geogrid 13 as a member is required to have friction resistance with the soil and tensile resistance in the slope height direction. It has been. For this reason, as shown in FIG. 4, a type configured to have longitudinal eye portions 13 a (mesh) having a shape obtained by uniaxially stretching high-density polyethylene and extending in one direction is employed. Therefore, as a geogrid as a geotextile used in this embodiment, other resin materials such as polypropylene and polyester, for example, having a mesh shape such as a square shape by biaxial stretching, can be used as long as the material has the same effect. It goes without saying that a grid-like member can be appropriately employed.

  As shown in FIG. 2, the horizontal receiving beam 20 is a surface cover 21 made of the same material as the geogrid 13 laid on the slope so as to cover the entire slope in the height direction of the slope 1. It is an on-site assembly member that covers the inner sandbags 22 and 23 and is fixed on the geogrid layer 12 on the slope, with a predetermined installation interval with respect to the slope height direction along the slope longitudinal direction. The beam is fixed to a predetermined position of the geogrid layer 12 by a fixing method described later so that the beam is substantially horizontal. In this way, the horizontal receiving beams 20 are arranged on the slope, and as shown in FIG. 1, the soil 8 is sprinkled on the slope (geogrid layer 12) between the horizontal receiving beams 20 and rolled to a predetermined thickness. By pressing, the soil 8 can be stabilized on the slope, and as a result, slipping downward in the slope direction is reliably prevented.

  Here, the structure of the surface impermeable construction 2 and the horizontal receiving beam 20 constructed on the slope of the waste 3 will be described with reference to FIG. The internal protective soil 5 is covered with a predetermined layer thickness (200 mm in this embodiment) on the waste 3 raised with a predetermined legal gradient. The internal protective soil 5 is preferably a cohesive soil capable of obtaining a sufficient adhesive force, and it is preferable to use an on-site generated soil if possible. Further, a non-woven mat 14 is laid as a cushioning material and a non-land adjuster so as to cover the inner protective soil 5. The mat thickness is preferably about 10 mm. A high-density polyethylene sheet (thickness: 1.5 mm) is laid on the nonwoven fabric mat 14 as the water-impervious sheet 10. Each of the water shielding sheets 10 is joined so as to maintain a water tightness by a known heat welding (hot welding) or the like while ensuring a predetermined overlap margin. A root sheet 15 is laid on the water shielding sheet 10. The root protection sheet 15 is a plant root blocking member for preventing plant roots (not shown) cultivated by the vegetation on the soil covering surface from penetrating the water shielding sheet 10, and impregnated with a known plant root repellent. Nonwoven fabric sheets, synthetic resin sheets that can be physically blocked, and the like can be used as appropriate. Needless to say, the thickness and specifications of these sheets and mats are not limited to those described above, and various types can be selected as appropriate as long as they satisfy the required standards.

  On the root prevention sheet 15, the geogrid layer 12 is formed so as to cover the entire slope. The geogrid 13 used in this embodiment is uniaxially stretched in the roll direction as shown in a part of FIG. 4, and has a grid shape in which elongated vertical eye portions 13a (mesh) are continuous in the roll direction. And is laid on the slope so that the direction of the elongated mesh matches the direction of the slope height. Further, a plurality of horizontal receiving beams 20 are fixed on the geogrid layer 12 (see FIG. 2). These horizontal receiving beams 20 are made of on-site assembly members fixed on the geogrid layer 12 by covering the inner sandbags 22 and 23 with a surface cover 21 made of the same material as the geogrid 13. In the present embodiment, the connection bar 25 is used to fix the surface cover 21 of the horizontal receiving beam 20 to the geogrid layer 12. This connection bar 25 is a flat strip of width × thickness × length (40 mm × 5 mm × 1 m) made of a high density polyethylene molded product of the same material as the geogrid 13 as shown in FIG. As the usage method, both the geometries generated by bending the vertical eye portion 13b of the other geogrid 13 into the vertical eye portion 13a of one geogrid 13 and having a vertical positional relationship continuously in the longitudinal direction. The connecting bar 25 is inserted into the gap 13c between the grids 13 so that the mesh portion is knitted. Since it is a strip-shaped member, it can reliably resist the shearing force in the direction of the height of the slope that occurs at the meshed portion of the geogrid 13.

  If predetermined shear resistance and tensile strength are ensured, instead of the strip-shaped connection bar 25 described above, a wire material such as a resin strand obtained by finishing a synthetic resin fiber into a stranded wire having a predetermined cross-sectional area is used. It is also possible to use one or a plurality of bundles.

  In the present embodiment, as shown in FIG. 3, the inside of the horizontal receiving beam 20 covered with the surface cover 21 is a sandbag 22 stacked in two steps, and a vegetation soil bag filled with a vegetation base material in the uppermost stage. 23 three-stage sandbags are housed. The lower soilbag 22 is preferably filled with the same material as the soil material. It should be noted that the number of piles of sandbags and the size of the cross section of the horizontal support beam 20 may be set according to the layer thickness of the earth covering work. It is preferable to allow a sufficient overlap margin for the surface cover 21, increase the cross-sectional dimension of the connection bar 25, and increase the number of used bars. In this embodiment, the sandbags are stacked to form the solid portion of the horizontal receiving beam 20. However, if the cross-sectional rigidity that can resist the sliding of the customer soil above the beam can be maintained, it can be handled by a beam using various alternative members. it can. For example, it is possible to adopt a thick-layer base material beam formed by spraying the beam position.

Next, with reference to each figure of FIG. 5, the construction method of the horizontal receiving beam 20 as a stable soil structure on the slope will be described. First, as shown in FIG. 5 (a), the upper end of the front cover 21 along a predetermined height above the geogrid layer 12 is formed slopes in the longitudinal direction of Homen, using the connection bar 25 Stick to the geogrid 13. As shown in FIG. 4, the fixing method at this time is integrated by connecting the connecting bars 25 into the gaps between the vertical meshes formed by engaging both the meshes. The dimensions of this time the front cover 21, FIG. 5 a lower end of the front cover 21 in a state where involving sandbags in three stages as shown in (b), geogrid layer at a position above the sandbags which stacked using connecting bar 25 12 It is preferable to have a length that secures a sufficient margin for bonding. Further, the sandbags stacked in three stages are horizontally arranged along the longitudinal direction so as to constitute the horizontal receiving beam 20 , and the surface cover 21 is covered with the piled sandbags so as to cover the sandbags of a predetermined length. 21 white junction of the lower end portion of, constructing a horizontal receiving beam 20 by weaving the geogrids layer 12 at a position above the sandbags using the connection bar 25 (see FIG. 2, FIG. 5 (c)). Thereafter, the cross-sectional shape of the horizontal receiving beam 20, particularly the beam height (the height of the sandbag to be stacked) is adjusted so that a predetermined covering thickness (30 cm in this embodiment) can be secured on the slope, and the beam height is adjusted. As a guideline, the soil 8 is rolled up on the slope and rolled to complete the cover work (see Fig. 1) . After that, vegetation work such as spraying plant seeds that match the vegetation condition around the site to the surface of the soil is applied, and the surface impermeable work 2 is greened. Through the above steps, it is possible to cover and green the surface water-impervious work 2 on the slope 1 where the water-impervious sheet 10 is laid.

  The above-mentioned stable structure of the soil is suitable for soil structures that are covered with soil so that the water shielding sheet etc. is not damaged, in addition to the above-mentioned surface impermeable work at the final disposal site for waste. Needless to say, the present invention can be applied with various modifications.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic perspective view which notched and showed a part of slope surface water-impervious construction to which one Example of the soil stabilization structure on the water-impervious sheet slope of this invention was applied. The schematic perspective view which removed the earth covering work so that the horizontal receiving beam of the stable soil structure on the water-impervious sheet slope shown in FIG. 1 might become clear. The partial expanded sectional view which showed the detailed structure of the horizontal surface receiving beam vicinity of the slope surface water-impervious construction shown in FIG. The elements on larger scale which showed the joining state of the geogrid using a connection bar. Construction sequence diagram schematically showing the procedure for constructing a horizontal receiving beam with a stable soil structure on the slope. The schematic structure sectional drawing which showed an example of the structure of the surface impermeable construction in the conventional waste final disposal site.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Slope 2 Surface impermeable construction 3 Waste 4 Corrugation 6 Corrugation concrete 8 Guest soil 10 Impermeable sheet 11
12 Geogrid Layer 13 Geogrid 20 Horizontal Beam 21 Surface Cover 22 Earth Crest 23 Vegetation Soil 25 Connection Bar

Claims (1)

Along the covered slopes on a water shield sheet laid geogrid forming the geogrid layer, to a predetermined height of the geogrid layer, fixed on the end of the front cover of the geogrid same material And placing a sandbag on the fixed portion of the surface cover, folding the lower end of the surface cover upward, and encasing the sandbag so as to cover and cover the lower end of the surface cover. Act surrounded by the above-arranged at predetermined intervals in the horizontal receiving beam formed by fixing the geogrid layer at the upper position Homen in the height direction of the sandbags, and the geogrid layer and the horizontal receiving beam method for constructing a soil dressing stable structure on water shield sheet method surface, characterized in that the soil cover on the surface with soil dressing.

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