JP6342347B2 - Laying method of temporary restraining material for embankment reinforced earth wall construction method - Google Patents

Description

The present invention relates to a method for laying a temporary restraining material of a plastic honeycomb structure used when a railway / road or a coastal structure is constructed by a banking reinforced earth wall construction method.

  In recent years, construction of reinforced embankments has been increasing in railway embankments and road embankment structures. In many cases, a geotextile (planar reinforcing material) is used as the reinforcing material in the reinforced embankment, but if the slope is steep, a wall work is required. In the wall work, there are many wall works in the form of wrapping sandbags and welded wire mesh with geotextiles, and in the form of L-shaped expanded metal connected to geotextiles. These wall surfaces are called divided wall surfaces.

  On the other hand, the wall surface in the form of wrapping temporary restraining materials such as sandbags and welded wire mesh with geotextile is used as the primary wall surface, and the deformation of the reinforced embankment is converged and then built as the secondary wall surface. There is an RRR method having a “high cast-in-place concrete wall surface”. In general, it has been clarified that the strength of the reinforced embankment increases as the rigidity of the wall work increases.

  The temporary holding material used in the RRR method, which is this rigid wall reinforced earth method, is required to have the following performance.

  (1) Ensure stability during construction.

  (2) Hold the drainage mechanism on the back of the retaining wall after completion, and at the same time protect the connection between the wall work and the reinforcement part.

  (3) Have sufficient strength to withstand handling during construction.

JP 2014-091915 A

Fumio Tatsuoka: Reinforced soil structure for restoration / reconstruction from the 2011 Great East Japan Earthquake. 13, 2011 August Geotechnical Society, Issues and Countermeasures for Ground Disasters during Earthquakes: Lessons and Recommendations for the 2011 Great East Japan Earthquake (First), July 2011 Nikkei Construction, pp. 34-43, 2011.10.20

  The temporary restraining material used as the primary wall surface of the conventional hard wall reinforced embankment wall construction method (RRR method) is 2 of "earth clay" for the RRR method and "L-shaped welded wire mesh" which is a welded wire mesh processed into an L shape. There are various types, but each has the following points to be improved.

  FIG. 11 is an explanatory diagram of problems in the case of sandbag construction.

  In this figure, 201 is the position of the sandbag before compaction, 202 is the position of the sandbag after compaction, 201A is the setback position, 202A is protruding by compaction, 203 is the concrete penetration, 203A is the planned line, 204 Is the planned wall thickness.

  “Dougou” has the characteristics that it is easy to adjust the accumulation height of the sandbag bag filled with filling material and the construction of the curved portion, because it is well-suited at the time of accumulation. On the other hand, it takes time to fill the filling material and transport the sandbag after filling. Alternatively, as shown in FIG. 11, there is a concern about the deterioration of the quality such as bulging to the front after the accumulation of sandbags, insufficient wall thickness of the covering concrete, lack of reinforcing steel cover, etc. It was necessary to set the design embankment slope considering the amount. In addition, the front surface of the sandbag accumulation is uneven due to the overhanging 202A due to compaction, and the planned wall thickness 204 is the thickness from this forefront (point of the mountain). The construction concrete is considerably larger than the design quantity, which is a cost burden on the construction side.

  FIG. 12 is an explanatory diagram of points to be improved in the case of a conventional L-type welded wire mesh.

  In this figure, 301 is a geotextile, 302 is a welded wire mesh, 303 is a spill-proof sheet, 304 is a crusher run, etc., and 305 is a fill material.

  As shown in this figure, when “L-shaped welded wire mesh” is used, the construction efficiency is greatly improved because there is no process for filling the padding material, compared with the case where “Dono” is used. In the case of construction at a part or the like, there is a high concern that the quality of the coated concrete will deteriorate due to rust of the welded wire mesh due to penetration of seawater by overtopping.

  In addition, since the head of the welded wire mesh is deformed during crushed stone rolling, there are also problems such as difficulty in positioning the setback, and a larger amount of crushed stone compared to the soil.

  Furthermore, in the case of reinforced soil earthquake-resistant abutments and reinforced soil-integrated bridges, since cement-impregnated gravel soil is used, unevenness occurs on the embankment after rolling, so the level and height of the welded wire mesh Adjustment took time, and it was necessary to improve this point in order to shorten the process.

As you can see,
(1) If there is no projected amount at the time of construction, the amount of biting concrete will increase.
(2) On the contrary, if the amount of protrusion is larger than planned, the cover of the reinforcing bars will be insufficient.

In the case of an L-shaped welded wire mesh, (1) When used for a coastal structure or the like, the coated concrete deteriorates due to the rust of the reinforcing bars of the welded wire mesh.
(2) Since the head of the welded wire mesh is deformed during the crushed stone rolling, it is difficult to determine the setback position.
(3) The amount of crushed stone is larger than in the case of clay.
(4) It takes time to adjust the level and height of the welded wire mesh.

In view of the above situation, the present invention solves the problem of the form of wrapping a sandbag or welded wire mesh used in a conventional reinforced embankment primary wall surface with geotextiles, and ensures stability during construction and handling during construction. An object of the present invention is to provide a method for laying a temporary restraining material for embankment reinforced earth wall construction having sufficient strength to withstand.

In order to achieve the above object, the present invention provides
[1] In the method of laying temporary restraining material for embankment reinforced earth wall construction method , by attaching an auxiliary sheet having a certain rigidity to the front side of the geosynthetic (geocell) of a three-dimensional honeycomb structure, it is in situ as a reinforced earth wall body. Is used for temporary reinforcement for embankment reinforcement earth wall construction with a geocell structure that secures the straightness of the concrete surface to be placed, and the entire geocell structure is rolled up with geosynthetic reinforcement to reinforce the embankment It is characterized by integrating the concrete of the vertical wall which is an important structure of the earth wall construction method .

[2] In the method of laying temporary restraining material for embankment reinforced earth wall construction, it is formed into a rectangular parallelepiped by attaching an auxiliary sheet with a certain rigidity so as to surround the entire four surfaces of the geosynthetic (geocell) of a three-dimensional honeycomb structure A temporary restraining material for embankment reinforced earth wall construction is provided , and the geocell structure is entirely wrapped with geosynthetic reinforcement, and the vertical wall, which is an important structure of embankment reinforcement earth wall construction, is used. It is characterized by integrating with concrete .

[ 3 ] In the method of laying temporary restraining material for embankment reinforced earth wall construction method, an auxiliary sheet having a certain rigidity is attached to the front side of the geosynthetic (geocell) with a three-dimensional honeycomb structure, so that it can be used as a reinforced earth wall body. Is used as a temporary restraining material for embankment reinforced earth wall construction with a geocell structure that ensures the straightness of the concrete surface to be placed. Is characterized in that the aperture holes are appropriately arranged so that the in-situ fresh concrete sufficiently penetrates the sheet and reaches the front surface of the geosynthetic (geocell) having a three-dimensional honeycomb structure.

[4] In the laying method of temporary restraining material for embankment reinforced earth wall construction, it is formed into a rectangular parallelepiped by attaching auxiliary sheets with a certain rigidity so as to surround the entire four surfaces of the geosynthetic (geocell) of a three-dimensional honeycomb structure For the auxiliary sheet with a certain rigidity used for the front of the auxiliary sheet, on-site fresh concrete is sufficient for this sheet. The opening holes are appropriately arranged so as to penetrate and reach the front surface of the geosynthetic (geocell) having a three-dimensional honeycomb structure .

According to the present invention, the following effects can be achieved.
(1) Instead of a welded wire mesh, a temporary holding part is formed by filling and rolling compacted crushed stone in a geosynthetics (geocell) of a three-dimensional honeycomb structure such as a high density polyethylene resin, so-called plastic honeycomb. The penetration of seawater and the like does not rust the welded wire rebar and degrade the quality of the coated concrete.

Therefore, it can be applied to a coastal revetment structure as a waterside disaster prevention work.
(2) Similarly, by using a plastic honeycomb and auxiliary sheet to form a three-dimensional structure, the quality of the coated concrete due to the protrusion of the wall, such as insufficient wall thickness and insufficient reinforcing steel cover, will deteriorate on the front surface after the accumulation of sandbags. (There is no need for an auxiliary sheet on the back side of the geocell).
(3) Similarly, since the auxiliary sheet and the honeycomb structure are structurally stable, deformation of the geocell structure during crushed stone rolling of the temporary restraining portion is suppressed. Therefore, it is almost unnecessary to set a design embankment gradient considering the setback amount, as in the case of using sandbags or welded wire mesh, and the concrete generated when using sandbags, welded wire mesh, etc. The amount of biting can be reduced (because of the honeycomb structure, it is strong against the rolling load).
(4) Since there is no step of filling the filling material (step of producing a sandbag) compared to the case of using “soilbag”, the construction efficiency can be remarkably improved and the construction period can be greatly shortened.
(5) The range of the temporary restraining portion can be freely changed by adjusting the quantity of the three-dimensional honeycomb structure and the expansion dimension.
(6) In particular, in the case of a reinforced soil earthquake-resistant abutment or a reinforced soil combined bridge, since the unrolled thickness is 15 cm, a geocell with a height of H = 15 cm is used. The construction management becomes easy (for example, Terracell M type. In the case of a normal reinforced embankment wall, when the rolling thickness is 30 cm, the one with a height of 30 cm is used).
(7) Since the geocell is made of high-density polyethylene resin, it is lighter and cheaper than a welded wire mesh or the like. Therefore, since both transportation cost and material construction cost can be reduced, the construction cost can be greatly reduced.

It is the drawing substitute photograph 1 which shows the carrying-in condition of the geocell used with the temporary restraining material for the embankment reinforcement earth wall method of this invention. It is drawing substitute photograph 2 which shows the expansion | deployment condition of the geocell used with the temporary restraining material for embankment reinforcement earth wall construction methods of this invention. It is a schematic diagram which shows the example of a different process of the geocell of the honeycomb structure used with the temporary restraining material for embankment reinforcement earth wall construction methods of this invention. It is a figure which shows the state which injected the crushed stone into the geocell of FIG. It is a schematic diagram which shows the geocell of the honeycomb structure which shows the Example of this invention (here it was comprised by 2 rows and 4 product sheet | seat welding). It is a schematic diagram which shows the state by which the auxiliary sheet was fixed to the front surface of the geocell of the honeycomb structure which shows the Example of this invention. It is a drawing substitute photograph which shows the state which the auxiliary sheet was fixed to the front surface of the geocell of the honeycomb structure which shows the Example of this invention, and the hole of the back surface. It is explanatory drawing of the temporary restraint of the honeycomb structure which shows the Example of this invention, and the rolling pressure of a main body embankment. It is explanatory drawing which shows the method of cutting the geocell of a honeycomb structure which shows the Example from which this invention differs (here it is comprised by 3 rows and 5 product sheet welding) on-site. It is explanatory drawing of temporary suppression of the geocell of the honeycomb structure which shows the Example of this invention, and rolling pressure of a main body embankment. It is explanatory drawing of the problem in the case of the conventional sandbag construction. It is explanatory drawing of the problem in the case of the conventional L-type welded wire mesh.

According to the embedding method of the temporary reinforcing material for the embankment reinforced earth wall construction method of the present invention, an auxiliary sheet having a certain rigidity is attached to the front side of the geosynthetic (geocell) having a three-dimensional honeycomb structure, so that it is in situ as a reinforcing earth wall body. Is used for temporary reinforcement for embankment reinforcement earth wall construction with a geocell structure that secures the straightness of the concrete surface to be placed, and the entire geocell structure is rolled up with geosynthetic reinforcement to reinforce the embankment The concrete of the vertical wall, which is an important structure of the earth wall method, is integrated .

  Hereinafter, embodiments of the present invention will be described in detail.

  In order to solve the problem of the geotextile wrapping of a sandbag or a welded wire mesh used for a conventional reinforced embankment primary wall, the present invention has a fixed structure on the front side of the geosynthetics (geocell) having a three-dimensional honeycomb structure. Secure the straightness of the concrete placement surface by attaching a rigid auxiliary sheet, or cutting the foremost sheet in its original position or at the factory with a cutter, etc. Provided is a temporary reinforcing material for embankment-reinforced earth walls in which a rectangular parallelepiped is formed by surrounding the entire four surfaces of geosynthetics (Geocel), and a primary wall surface is formed by filling and rolling compacted crushed stones therein.

The construction procedure is as follows.
(1) Geocell expansion FIG. 1 is a drawing-substituting photograph 1 showing the carrying-in state of a geocell used in the temporary restraining material for embankment reinforcing earth wall method of the present invention, and FIG. 2 is a drawing substitute showing the expansion state of the geocell. Photo 2.

  The geocell carried in the state as shown in FIG. 1 is formed into a cubic shape with a three-dimensional honeycomb-shaped geocell with an auxiliary frame of a reinforcing bar mesh as shown in FIG. In addition, as a material of a geocell, a high density polyethylene resin etc. are used.

  FIG. 3 is a schematic diagram showing different processing examples of the geocell of the honeycomb structure used in the temporary restraining material for embankment reinforcing earth wall method of the present invention, and FIG. 4 is a schematic diagram showing a state in which crushed stones are put into the geocell after the processing. FIG.

  In these drawings, 1-4 are auxiliary sheets of the same material as Geocell, and 5 is crushed stone. As shown in FIG. 3, two or three rows of geocells of the honeycomb structure can be processed on-site so as to be surrounded by auxiliary sheets 1 to 4 and installed at a predetermined position. In this case, the length direction is an arbitrary length according to the situation of the original position. As shown in FIG. 5, crushed stone 5 is put into the honeycomb structure processed in this way.

Thus, if necessary, the auxiliary sheet 1 to 4 can be used to surround the honeycomb structure, but as a basic structure, the auxiliary sheet 1 is attached only to the front surface of the geocell as described below. Shall.
(2) Fixing of auxiliary sheet FIG. 5 is a schematic view showing a geocell of a honeycomb structure (here, constituted by two rows and four product sheets welded) showing an embodiment of the present invention, and FIG. FIG. 7 is a schematic diagram showing a state in which the auxiliary sheet is fixed to the front surface of the geocell, FIG. 7 is a drawing substitute photograph showing the state in which the auxiliary sheet is fixed to the front surface of the geocell and the backmost hole, and FIG. 8 is a diagram of the honeycomb structure. It is explanatory drawing of temporary restraining and rolling of main body embankment.

  In these drawings, 1 is an auxiliary sheet (perforated specification), and 6 is a drainage hole. In addition, a standard expansion | deployment condition is as showing in FIG. 5, and it can adjust to about 500-900 mm.

  The auxiliary sheet 1 made of the same material as the geocell (for example, high-density polyethylene) is bonded to the front surface of the geocell of the honeycomb structure formed as shown in FIG. 5 with a plastic screw or an insulation lock.

  The auxiliary sheet 1 has a perforated specification. After the retaining wall is completed, since the rigid wall surface work is integrated with the geosynthetic reinforcement, the on-site fresh concrete sufficiently penetrates the auxiliary sheet 1 and has a three-dimensional honeycomb structure. A geocell structure in which opening holes are appropriately arranged so as to reach the front surface (D surface) of the geosynthetic (geocell).

  Fresh concrete permeates the E portion filled with the crushed stone 5 and can be integrated with the rigid wall surface of the retaining wall housing (integration of the temporary holding portion and the retaining wall housing is further strengthened).

  In addition, a suction prevention sheet is attached to the backmost geocell sheet, and in order to collect the permeated water from the back embankment to the temporary holding part and drain it from the lower part, as shown in FIG. Open.

  As described above, in-situ fresh concrete sufficiently penetrates the auxiliary sheet 1 having a certain rigidity (perforated specification) 1 and reaches the front surface (D surface) of the geosynthetic (geocell) having a three-dimensional honeycomb structure. An example of a geocell structure with appropriately arranged aperture holes is shown.

  FIG. 9 is an explanatory view showing a method for cutting on site the geocells of the honeycomb structure (in this case, composed of three rows and five product sheets welded) showing different embodiments of the present invention.

  In this embodiment, as shown in FIG. 9, a honeycomb structure geocell welded with 5 sheets of geocell product sheets is spread, and then the foremost product sheet is cut with a cutter or the like in its original position. This is an example in which the auxiliary sheet 1 is connected with staples, tapping screws or the like after securing the properties. Also in this case, the front auxiliary sheet 1 has a perforated specification so that the fresh concrete penetrates into the geocell portion filled with crushed stone and is integrated with the rigid wall surface of the retaining wall frame in the same manner as described above.

Because the rigid wall construction is integrated with the geosynthetic reinforcement, the opening-site holes allow the in-situ fresh concrete to sufficiently penetrate the auxiliary sheet and reach the front surface (D surface) of the geosynthetic (geocell) with a three-dimensional honeycomb structure. Is a properly arranged geocell structure.
(3) Temporary suppression of honeycomb structure and rolling pressure of main body embankment FIG. 10 is an explanatory diagram of temporary suppression of geocell and rolling pressure of main body embankment of a honeycomb structure according to an embodiment of the present invention.
(A) First layer rolling and rolling [see FIG. 10 (a)]
In this figure, 11 is a geotextile, 12 is a temporary restraint of the honeycomb structure, and 13 is an embankment material.
(B) Second layer rolling and rolling [see FIG. 10 (b)]
(C) Thereafter, this operation is repeated. Thus, the crushed stone is filled and rolled into the geocell as a filling material, and the entire geocell structure is rolled up with the geosynthetic reinforcement material. Construct the restraining structure (primary wall surface).

  The above is the case where the height of the geocell is 15 cm. When the height of the geocell is 30 cm, the entire geocell structure is wound with the geosynthetic reinforcement after the first layering and rolling operation.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

The method of laying the temporary restraining material for the embankment reinforced earth wall construction method of the present invention can shorten the construction period, change the range of the temporary restraining part, and can reduce the construction cost. It can be used as a material and its laying method.

1-4 Auxiliary sheet 5 Crushed stone 6 Drainage hole

Claims (4)

Geocell structure that secures linearity on the concrete surface side that is placed in place as a reinforced soil wall by attaching an auxiliary sheet with a certain rigidity to the front side of the geosynthetic (geocell) with a three-dimensional honeycomb structure uses a Sheng soil mechanically stabilized earth for temporary restraining material you provided with, rolling across the geocell structure with geosynthetic reinforcement, the concrete of the vertical wall is important structure embankment mechanically stabilized earth A method for laying a temporary holding material for embankment-reinforced earth wall construction, characterized by being integrated. By attaching the auxiliary sheet which has a certain rigidity so as to surround the entire four sides of geosynthetic three-dimensional honeycomb structure (geocell), it includes a geocell structure formed in a rectangular parallelepiped Sheng soil mechanically stabilized earth for temporary An embankment reinforced soil wall using a restraining material , wherein the entire geocell structure is rolled up with a geosynthetic reinforcement material, and the vertical wall concrete, which is an important structure of the embankment reinforced soil wall construction method, is integrated. A method of laying temporary holding materials for construction methods. Geocell structure that secures linearity on the concrete surface side that is placed in place as a reinforced soil wall by attaching an auxiliary sheet with a certain rigidity to the front side of the geosynthetic (geocell) with a three-dimensional honeycomb structure The temporary reinforcing material for embankment reinforced earth wall construction is provided , and among the auxiliary sheets , the auxiliary sheet with a certain rigidity used on the front surface is sufficiently infiltrated with the on-site fresh concrete and the three-dimensional honeycomb. A method for laying temporary holding materials for embankment reinforced earth wall construction, wherein the opening holes are appropriately arranged to reach the front of the geosynthetic (geocell) of the structure. Temporary restraint material for embankment reinforced earth wall construction comprising a geocell structure formed in a rectangular parallelepiped by attaching an auxiliary sheet having a certain rigidity so as to surround the entire four surfaces of the geosynthetic (geocell) of a three-dimensional honeycomb structure As for the auxiliary sheet with a certain rigidity used for the front surface among the auxiliary sheets, the cast-in-place fresh concrete sufficiently penetrates the sheet and reaches the front surface of the geosynthetic (geocell) with a three-dimensional honeycomb structure. A method for laying temporary holding materials for embankment reinforced earth wall construction, characterized in that the opening holes are appropriately arranged .