JP2008115578A - Retaining wall - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steel retaining wall which is more stable than a retaining wall formed of gabions, facilitates surface compaction of earth etc., and can be constructed more easily than a geogrid reinforced soil wall. <P>SOLUTION: The retaining wall is constructed by stacking steel forms in multiple stages. Each steel form consists of a front mesh plate and a bottom mesh plate, and is formed in L-shape in cross section. The bottom mesh plate has a depthwise length at least 1.5 times or more a height of a vertical front mesh plate, and both the front mesh plate and the bottom mesh plate are connected together by diagonal ties to retain the L-shape. Thus the multi-stage stacking retaining wall is obtained by employing the steel forms. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a multistage stacked retaining wall by a steel mold using an expanded metal or the like and a construction method thereof.

  In the past, a technique for constructing a retaining wall-like structure by stacking a plurality of futon baskets in a staircase shape for protecting the surface erosion of a slope is known. Futonkago is generally a rectangular parallelepiped cage made of wire mesh, filled with earth and sand, crushed stone, etc., and piled up in steps. An example disclosed in Patent Document 1 is given as an example of the Futon basket.

  Futonkago has been used mainly for revetments, and has been used by filling crushed stones and chestnuts. In recent years, it has been used by filling earth and sand in places where there is no concern about scouring. Yes. At that time, an anti-spilling material or the like is applied to the inner wall surface of the futon basket to prevent the outflow of fine sand and soil.

  However, Futonkago is mainly for the purpose of protecting the surface erosion of the slope, and it cannot be denied that the strength is insufficient from the viewpoint of the stability of the whole embankment and the stability of the structure. Therefore, caution is required for use on unstable ground and sloping ground, and it is not possible to make a structure with a very high wall height.

  In addition, when filling sand and sand into the Futong basket, naturally it is necessary to compact or roll the earth and sand, but since the Futong basket has a metal mesh on the mountain side and the left and right sides in addition to the wall surface, the metal mesh is obstructive. As a result, there was a disadvantage that sufficient rolling could not be performed.

  On the other hand, as a method for stabilizing slopes and greening, a reinforcing structure such as a geogrid is connected to the back of a wire mesh L-shaped steel formwork and stacked to construct a retaining wall-like structure. The reinforced earth wall method is well known. An example disclosed in Patent Document 2 is an example of the reinforced earth wall construction method.

  The reinforced earth wall construction method using geogrid plays a role of protecting the wall surface with a part of an L-shaped steel formwork called a slope forming material, and the geogrid connected to the back side reinforces the entire structure. I'm in charge. Slope forming material is a member used for the purpose of wall surface formation. Generally, the length of the bottom surface part is the same as or less than the height of the wall surface part, and it is stable enough not to fall when placed on a flat surface. is doing. That is, the slope forming material of the reinforced earth wall construction method using geogrid is a member that can exhibit its function only after being connected to geogrid.

  In general, the reinforced earth wall construction method using geogrid has established the structural calculation principle using arc slip calculation, wedge fracture calculation, and ground bearing capacity calculation, and is known as a technology that can build a highly reliable embankment structure. ing.

  However, on the other hand, the reinforced earth wall construction method using geogrids has more parts than Futongago, and the necessary strength of geogrids is calculated by structural calculation, and the grade of geogrids corresponding to that is selected from the calculation results. Because it had to be done, it took time and effort before the construction. Therefore, it was a complicated method to construct the retaining wall in a place that would be too large to use the reinforced earth wall method.

Japanese Patent No. 3308262 Japanese Patent No. 2870275

  It is an object of the present invention to provide a steel retaining wall that is more stable than a conventional futon cage, is easy to roll earth and sand, and can be constructed more easily than a reinforced earth wall by geogrid.

  The present invention has been made to solve this problem, and the invention according to claim 1 is a steel mold having an L-shaped cross section composed of a front mesh plate and a bottom mesh plate. The length in the depth direction is at least 1.5 times the height of the front net plate in the direction perpendicular to the bottom net plate, and the front net plate and the bottom net plate are connected with a slant tie material to form an L shape. It is a steel formwork for multistage stacked retaining walls that retains its shape.

  The depth in the depth direction of the bottom net plate cannot resist the earth pressure applied to the net plate on the wall surface side unless it is sufficiently longer than the height of the front net plate. This length must be at least 1.5 times. Furthermore, in order to resist the earth pressure applied to the front net plate and maintain the angle between the front net plate and the bottom net plate, a diagonal tie material is provided between them.

  The invention described in claim 2 is a steel mold for multi-stage stacked retaining walls in which the angle formed by the front mesh plate and the bottom mesh plate is 45 ° or more and 90 ° or less.

  A smaller connection angle is more stable, but if it is 45 ° or less, a stable embankment structure can be constructed without installing a steel frame. If it is larger than 90 °, a stable retaining wall cannot be constructed.

  A third aspect of the present invention is the steel mold according to the first or second aspect, wherein the front net plate is provided with a sucking prevention material.

  When earth and sand containing fine particles are used for the back-filling material, if only the formwork is used, the eyes will be too coarse and spillage will occur. In order to prevent this, a sucking prevention material finer than the mesh of the steel mold is provided on the front panel.

  The invention according to claim 4 is a multi-stage stacking retaining wall constructed using the steel mold according to any one of claims 1 to 3.

  By using the steel mold for multistage retaining walls according to the present invention, it is possible to easily perform the rolling work that could not be sufficiently performed with the Futon basket using earth and sand as a filler. In addition, it is possible to construct a retaining wall structure that is stronger than a conventional futon basket.

  By using the steel formwork for multistage retaining walls according to the present invention, it is possible to construct a retaining wall more easily than a reinforced earth wall by geotextile.

  FIG. 1 is a perspective view of a steel mold used in the present invention. The steel mold 1 is composed of a front net plate 2 and a bottom net plate 3 which are the walls of the retaining wall. Although the front part net board 2 and the bottom part net board 3 should just be net shape, it is good to use an expanded metal especially. The depth of the bottom mesh plate in the depth direction cannot resist the earth pressure applied to the front mesh plate unless it is sufficiently longer than the height of the front mesh plate. This length must be at least 1.5 times the height of the front screen. More preferably, it is at least twice the height of the front net plate.

  The steel mold 1 is manufactured by bending one mesh plate or welding two mesh plates, but the manufacturing method is not particularly limited as long as it can withstand earth pressure from the back. The angle formed by the front screen 2 and the bottom screen 3 is 45 ° or more and 90 ° or less. A smaller angle is more stable, but if it is 45 ° or less, a stable embankment structure can be constructed without installing a steel frame. If it is larger than 90 °, a stable retaining wall cannot be constructed.

  The size of the steel mold 1 is not particularly limited, but the optimum size is that the width of the front net 2 and the bottom net 3 is about 2 m, the height of the front net 2 is about 50 cm, the bottom net The depth of 3 is about 1m30cm, and if it is this size, it can be carried by human hands and is easy to construct.

  2 to 6 show the construction procedure of the multi-tiered retaining wall.

  FIG. 2 illustrates a state in which the steel molds 1 are connected to each other with a clip 5, and a sucking prevention material 6 is attached to the front net 2 of the steel mold 1. The steel formwork 1 is connected with a clip 5 in order to have a wall integrity after the retaining wall is constructed. It is better to have more connection points, but about two are sufficient.

  The sucking prevention material 6 is attached to the side of the front net 2 that is filled with earth, sand, crushed stone, or the like. When using earth and sand containing fine particles as the backfill material, if it is only a steel formwork, the eyes are too rough, causing spillage or surface erosion due to water. In order to prevent these, a sucking prevention material is used. The suction preventing material 6 is a resin sheet having holes in a mesh shape, and the hole diameter needs to be finer than the mesh of the steel mold.

  FIG. 3 is a perspective view when the anti-suction material 6 is attached to the front surface mesh plate 2 of the steel mold 1 and then the slant tie material 4 is installed. The slant tie material 4 is laid so that the front net plate 2 of the steel mold 1 does not rise or deform when filled with earth or sand, and the number is not particularly limited. In the best mode, the interval between adjacent slant tie members 4 should be about 50 cm.

  FIG. 4 is a perspective view when earth and sand are filled after the slant tie material 4 is installed. When constructing a banking structure, it is common in earthwork to roll from 25 cm to 30 cm, but the same treatment can be performed when constructing a retaining wall-like structure using this steel mold 1. desirable. That is, after the slant tie material 4 is installed, earth and sand are carried in a thickness of about 50 cm, and then rolled with a compacting machine to form an embankment layer having a thickness of 25 cm to 30 cm. When the height of the steel mold 1 is 50 cm, the steel retaining wall for one stage can be constructed by carrying out the work of carrying in earth and sand and rolling twice.

  FIG. 5 is a cross-sectional view when the earth and sand 7 is filled after the oblique tie material 4 is installed.

  FIG. 6 is a cross-sectional view when the steel molds 1 are stacked. As shown in FIG. 6, the constructed steel retaining walls are stacked stepwise. The construction procedure for each step is as described above, and the steps are repeated for the number of steps to construct a multistage retaining wall. The virtual gradient 9 can be created by retracting the front surface portion of each stage of the steel form at regular intervals each time it is stacked. The magnitude of the virtual gradient 9 can be adjusted by the receding width of the steel mold.

  FIG. 7 is a perspective view of the constructed multi-tiered retaining wall.

  By constructing multi-tiered retaining walls using steel molds according to the present invention, it is stronger than futon cages filled with earth and sand and more easily than retaining earth walls using geotextiles. it can.

It is a perspective view of the steel mold for multistage stacking retaining walls. It is a perspective view at the time of providing the suction prevention material at the time of this invention construction. It is a perspective view in the case of the slant tie material installation at the time of this invention construction. It is a perspective view at the time of carrying in earth and sand at the time of this invention construction. It is sectional drawing at the time of carrying in earth and sand at the time of this invention construction. It is sectional drawing of the multistage stacking retaining wall at the time of this invention construction. It is a perspective view of the completed multistage stacking retaining wall of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel formwork 2 Front part net board 3 Bottom part net board 4 Diagonal tie material 5 Clip 6 Suction prevention material 7 Earth and sand, crushed stone, etc. 8 Ground mountain 9 Virtual gradient

Claims (4)

  A steel mold having an L-shaped cross section composed of a front mesh plate and a bottom mesh plate, wherein the depth of the bottom mesh plate in the depth direction is at least 1 higher than the height of the front mesh plate perpendicular to the bottom mesh plate. .Steel formwork for multi-stage stacking walls that is more than 5 times and retains the L shape by connecting the front and bottom mesh plates with diagonal tie materials.   The steel formwork for multistage stacking retaining walls whose angle which a front part net board and a bottom part net board make with the steel formwork of Claim 1 is 45 degrees or more and 90 degrees or less.   3. A steel mold for a multistage stacking retaining wall according to claim 1 or 2, wherein an anti-suction material is provided on the front net plate.   A multistage stacked retaining wall constructed using the steel mold according to any one of claims 1 to 3.