JPH0364006B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] This invention is applicable to the construction of roads, railways, rivers, residential land construction, etc., when forming embankments, wall materials are installed approximately vertically on the ground, and reinforcement is applied to the back side of the wall materials. This method involves burying materials in layers in order to form a soil layer and reinforcing the embankment using the frictional force between the soil particles and the reinforcing material. This invention relates to a reinforced embankment construction method that uses a spiral reinforcing material that is wound into a coiled shape to further enhance the reinforcing effect. [Conventional technology] Normally, when constructing an embankment for road maintenance, etc., when constructing on a steep slope or when the height of the embankment is high, the slope length is As a result, they tended to be very long, requiring wide land widths and increasing construction costs. For this reason, earth retaining methods such as concrete retaining wall materials have been used to narrow the site width, but in embankments on soft ground, retaining wall materials are easily destroyed, and the foundation piles up to the supporting ground are easily damaged. Because it is necessary, it has become a problem from both economic and safety points of view. On the other hand, there is a generally known construction method (Japanese Patent Publication No. 1974-25174) in which a soil layer is formed while strip-shaped reinforcing material is buried, and the embankment is reinforced by the frictional force between the soil particles and the strip-shaped reinforcing material. . This method of reinforcing the embankment while burying reinforcing materials involves burying reinforcing materials that exhibit high resistance to pulling forces in layers in the soil, which originally has little resistance to tensile forces. This takes advantage of the fact that the frictional force acting between the reinforcing agent and the soil transforms the embankment material into a material that appears to have adhesive force added to its inherent shear resistance. The reinforcing material used in this construction method must provide sufficient frictional resistance with the soil, have the necessary strength against tensile force, be of uniform quality, be highly reliable, and be durable. etc. are required. [Problems to be solved by the invention] However, the above construction method (Japanese Patent Publication No. 44-25174)
The reinforcing materials used in the The frictional force that occurs between the material and the soil is only generated on the front and back surfaces of the reinforcing material in the width direction, and almost no frictional force is generated on both left and right sides of the reinforcing material in the thickness direction of the reinforcing material. Although the soil layer in which the reinforcing material is buried is three-dimensional, reinforcement with a reinforcing material that takes full advantage of the three-dimensional characteristics of the soil layer has not been carried out. In this case, for example, if a cylindrical reinforcing material is used, it is possible to generate frictional force with the soil on both the left and right sides of the reinforcing material, but the surrounding surface of the reinforcing material is Because high compressive force is constantly acting on the material, it is necessary to have enough strength and rigidity to resist this compressive force and not deform.As a result, reinforcing materials must have considerable weight and rigidity. However, there is a problem in that the reinforcing material cannot be buried easily. Moreover, if the rigidity is too high, it will not be able to follow the deformation caused by the sinking of the embankment, and as a result, the reinforcing material may be damaged, or a small gap may be created between it and the soil, reducing the frictional force. There are problems such as the inability to achieve the desired effect. In view of the above-mentioned points, this invention
Based on the recognition that it is more effective to use three-dimensional reinforcing materials than dimensional reinforcing materials, we have developed a helical material made by winding rod-shaped materials into a spiral (coil-like) shape as a three-dimensional reinforcing material. By using the shape of the mold, it has the same burying workability as conventional two-dimensional strip-shaped reinforcing materials, while fully demonstrating its function as a three-dimensional reinforcing material, further increasing the reinforcing effect. The purpose of this paper is to provide a reinforced embankment construction method using a spiral reinforcing material that can be used as a reinforcement material. [Means for Solving the Problems] In order to achieve the above-mentioned objects, the present invention, when forming an embankment, first installs a wall material on the ground in a substantially vertical direction, and then installs a wall material on the back side of the wall material. Attach one end of a helical reinforcing material made of a bar-shaped material spirally wound, lay the helical reinforcing material on the back side of the wall material in a direction approximately perpendicular to the back surface, and then pour earth and sand onto the helical reinforcing material. A construction method that consists of completely burying a helical reinforcing material made of rolled rod-shaped material in a spiral shape, and then rolling it down to a specified soil layer thickness, and repeating this process to form an embankment. Consisting of [Operation] The present invention having the above configuration operates as follows. In other words, the helical reinforcing material, which is made by spirally wrapping rod-shaped materials buried in layers on the back side of the wall material, exerts a frictional force with the soil particles, and the It acts as if it were adding adhesive force to the existing shear resistance force. [Example] Hereinafter, the present invention will be described in more detail based on the example shown in the drawings. Here, Fig. 1 is a schematic overall side view, Fig. 2 is a schematic overall front view, Fig. 3 is a perspective view of the spiral reinforcement, and Fig. 4 A to C are a rear view, side view, and plan view of the wall material. 5A to 5M are schematic process diagrams of the construction method, and FIGS. 6A and 6B are schematic overall front views showing other embodiments. In the figure, the soil structure constituting the embankment constructed using this construction method consists of a wall material 1 installed approximately vertically on the ground, a spiral reinforcing material 2 buried on the back side of the wall material 1, and the embankment. It is composed of 3 pieces of earth and sand. A plurality of wall materials 1 are installed adjacent to each other in the vertical and horizontal directions at the end of the embankment to form a retaining wall, thereby making the slope of the embankment approximately perpendicular to the conventional method. This serves to eliminate the need for long slopes consisting of sloped surfaces. The wall material 1 is composed of a reinforced concrete block, which has a rectangular shape, and has stepped portions formed at its upper, lower, left, and right edges, and these stepped portions allow for smooth engagement with separate wall materials. is taken into account. Note that the material of the wall material 1 may be made of steel instead of reinforced concrete, and the edge may have an uneven portion instead of a stepped portion. Two connecting holes 4 are formed in the upper and lower edges of the wall material 1 in the vertical direction. The connecting hole 4 is a hole formed for embedding a rod-shaped member 5 used for mutually connecting the wall materials 1 installed above and below. Then, a rod-shaped member 5 embedded in the connecting hole 4
This prevents each wall material 1 from shifting in the left-right and front-back directions. As shown in FIG. 3, the helical reinforcing material 2 is made by winding a rod-shaped material with a small diameter into a spiral shape (coil shape). The diameter of the bar, the outer diameter of the helix, and its pitch are determined in consideration of conditions such as the state of the soil at the location where the helical reinforcing material 2 is buried and the height of the embankment. In this case, the spacing between the spiral pitches must be at least large enough to completely fill the inside of the spiral with soil particles. Since the helical reinforcing material 2 is buried in the embankment earth and sand 3 and tensile force acts between it and the embankment earth and sand 3, the helical reinforcing material 2 is made of a material that has the necessary strength for a predetermined tensile force, such as metal. , synthetic resin, etc. are used. In this case, in order to increase durability, it is more preferable to galvanize the surface, coat with anticorrosion paint, or coat with synthetic resin. Since the end 2a of the spiral reinforcing material 2 is attached to the back surface 1a of the wall material 1, the end 2a is finished in a ring shape in the same plane, and this ring-shaped end 2
A is finished so as to be a plane perpendicular to the axial direction of the reinforcing member 2. A reinforcing material mounting portion 6 for attaching an end portion 2a of the spiral reinforcing material 2 is provided on the back surface 1a of the wall material 1. The reinforcing material attachment part 6 is composed of an anchor 6a, a band-shaped presser plate 6b, and a nut 6c. Among these, the base end of the anchor 6a is completely embedded and fixed in the wall material 1. Further, a screw for screwing a nut 6c is cut into the tip side of the anchor 6a protruding from the back surface 1a of the wall material 1.
A hole is bored in the center of the band-shaped holding plate 6b, through which the distal end side of the anchor 6a passes. The length from the center of the hole of the band-shaped presser plate 6b to both ends is at least larger than the outer diameter of the helix of the helical reinforcing member 2. The reinforcing material attaching part 6 attaches the spiral reinforcing material 2 to the wall material 1 by sandwiching the end 2a of the helical reinforcing material 2 between the back surface 1a of the wall material 1 and the band-shaped pressing plate 6b.
It is attached to the back 1a of the In this case,
The spiral reinforcing material 2 attached to the reinforcing material attachment part 6 is attached to the back surface 1a of the wall material 1 and the band-shaped pressing plate 6b.
This prevents bending moments, torsional moments, or shearing forces from occurring in the reinforcement attachment portion 6, and prevents the cause of damage to the reinforcement attachment portion 6. can be removed. Next, the steps of the construction method will be explained with reference to FIGS. 5A to 5M. First, at the installation location of wall material 1 on the ground,
Level the ground at the bottom of the foundation, and form the foundation with foundation stone, foundation concrete, etc. The foundation surface will be constructed horizontally. Insert reinforcing bars etc. are embedded in the foundation concrete at appropriate intervals in advance. (See FIG. 5A) Next, the wall material 1, which will be the lowest stage of the retaining wall, is installed on the foundation in a horizontally connected manner. The wall material 1 is installed in a vertical direction, that is, perpendicular to a horizontal foundation surface. In this case, the above-mentioned reinforcing bars are inserted and installed into the connection holes 4 formed at the lower edge of the wall material 1. The wall material 1 can be accurately attached to a predetermined installation location by means of the reinforcing bars. In addition, when installing wall materials 1 in a connected manner, install so that there are no gaps between adjacent wall materials 1 and 1 (see Figure 5B). After all of the wall materials 1 are connected and installed on the foundation, embankment earth and sand 3 is spread and spread on the back side 1a of the wall materials 1 until the height is, for example, 40 cm. (See FIG. 5C) Thereafter, the surface of the embankment earth and sand 3 is uniformly compacted using a compaction machine. For example, the height of embankment earth and sand 3 is 40cm
Roll it down until it becomes 30cm. (See FIG. 5D) Next, the required number of spiral reinforcing materials 2 are laid on the surface of the compacted embankment earth 3. The laying work is carried out so that the core direction of each spiral reinforcing material 2 is perpendicular to the wall surface material 1. In parallel with this installation work,
The end 2a of the spiral reinforcing material 2 is attached to the back surface 1 of the wall material 1.
Attach to a. (Refer to Fig. 5E) The installation work is performed by attaching the anchor 6 of the reinforcing material attachment part 6.
Attach the ring-shaped inside of the end portion 2a so that it fits into the tip side of the anchor 6a, fit the band-shaped presser plate 6b to the tip side of the anchor 6a from the outside, and finally screw the nut 6c into the tip side of the anchor 6a. and complete. As a result, the end portion 2a of the spiral reinforcing member 2 is attached to the back surface 1a of the wall material 1 by being sandwiched between the back surface 1a of the wall material 1 and the band-shaped pressing plate 6b from the front and back. After laying the lowest helical reinforcing material 2, embankment earth and sand 3 is spread out inside and above the helical reinforcing material 2, and the helical reinforcing material 2 is completely buried in the embankment earth and sand 3. (See Figure 5F) Thereafter, the surface of the embankment earth and sand 3 is uniformly compacted using a compaction machine. For example, the height of embankment earth and sand 3 is 40cm
Roll it down until it becomes 30cm. (See FIG. 5G.) Thereafter, the second stage spiral reinforcing material 2 is buried in the embankment earth and sand 3 by repeating the same construction process as described above. (See FIGS. 5H to 5L) After forming the embankment surface up to the height of the lowest wall material 1, the second wall material 1 is installed perpendicularly above the lowest wall material 1. As shown in FIG. 2, the second-tier wall material 1 is attached with the right half and left half of the wall material 1 above the separate wall members 1 at the bottom. At the time of installation, the lower half of the rod-shaped member 5 is embedded in the connecting hole 4 formed in advance at the upper edge of the lowermost wall material 1. Then, insert the upper half of this rod-shaped material 5 into the communication hole 4 formed at the lower edge of the second-stage wall material 1, and place the second-stage wall material 1 above the wall material 1 in the lowest section.
are installed in a staggered manner. In this case, the construction is performed so that no gaps are created at the joints between the adjacent wall materials 1, 1 in the second stage. (See Figure 5M) Thereafter, the same construction process as described above is repeated to construct the embankment. It should be noted that this invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the invention. For example, the present invention can be applied to wall materials 1 that are long in the vertical direction or horizontal direction as shown in FIGS. 6A and 6B. [Example] Hereinafter, an example will be described in which a spiral reinforcing material according to the present invention is compared with a conventional belt-shaped reinforcing material. -Experimental example 1 (static experiment)- (1) Experimental method Experimental equipment The reinforced soil retaining wall model used in the experiment was 30cm high and wide.
It is a wooden box measuring 70cm and 20cm deep. The sides and back were fixed, and the retaining wall was movable. Reinforcement material The length of both the strip reinforcement material and the spiral reinforcement material (2 cm diameter, wire diameter 2 mm) was 17 cm, and the surface area was 28.6 cm ² and 45.7 cm ² to examine the effect of this.
type was used. Embankment materials Sandy soil (Toyoura standard sand) and clay soil (collected in the Okuyama district of Nagasaki City) were used as embankment materials. This was to investigate the difference in effectiveness depending on the type of embankment material.
Table 1 shows the soil characteristics of clayey soil.

[Table] Experimental procedure The weight of one layer is 1/3 of the total weight of the embankment packed in the experimental model. One layer of embankment material is placed from the bottom, and after compaction, reinforcing material is laid. In this step, the embankment material,
A reinforced soil retaining wall model was constructed by installing reinforcement materials alternately. However, the reinforcing materials were placed in a square shape only in the center so that the spacing between the reinforcing materials was 10 cm when viewed from the front. Place this model on a mounting device (CBR test device),
A compressive load was applied to the central surface where the reinforcing material was located via a steel plate. The loading method was a strain control method with a strain rate of 1 mm/min. The resulting load and horizontal displacement of the retaining wall were measured, and the horizontal displacement was taken as the average of the readings from dial gauges attached 1 cm from the upper and lower ends of the retaining wall. Loading was carried out in this manner until the maximum load appeared or the top end displacement reached 30 mm. Experimental details In order to investigate the effects of different reinforcement shapes, numbers of reinforcements, and embankment materials, experiments were conducted under various conditions. (2) Experimental results and discussion Differences depending on the shape of the reinforcing material Figures 7 and 8 show examples of experimental results. Similarly, Table 2 summarizes the experimental results under each setting condition. If we compare the maximum load up to a horizontal displacement of 10 mm from this table depending on the shape of the reinforcing material, we can see that the helical reinforcing material is larger in all cases. It is also clear from FIGS. 7 and 8 that the horizontal displacement of the helical reinforcement is smaller for the same load. From these facts, it can be said that the spiral reinforcing material has a better reinforcing effect than the strip reinforcing material. This is because in the case of spiral reinforcing materials, because of their three-dimensional shape, friction with soil particles is expected to be greater than with band-shaped reinforcing materials, and soil particles are filled inside the reinforcing material, making the reinforcing material appear rod-shaped. This is thought to be because the soil and reinforcement become more integrated over time. Furthermore, unlike strip-shaped reinforcement, a friction effect can be expected on the sides of the spiral reinforcement, so it is characterized by its ability to strongly integrate with the soil in the left and right directions.

〔Effect of the invention〕

As is clear from the above description, the present invention has the following effects. (1) Since the helical reinforcing material, which is made by winding a bar material into a spiral (coil shape), has a three-dimensional shape, the direction of the surface that causes friction with soil particles changes, and it is difficult to use the reinforcing material such as the strip-shaped reinforcing material. It is expected that friction with soil particles will be greater than that of a flat, two-dimensional material, and a higher reinforcing effect can be expected than with conventional strip-shaped reinforcing materials. (2) Since it is a helical type in which rod-shaped materials are wound into a spiral (coil shape), unlike flat reinforcement materials such as conventional strip reinforcement materials, frictional force is generated between the reinforcement material and the embankment on both the left and right sides. It is possible to effectively utilize the earth pressure on both the left and right sides of the reinforcing material, which could not be used in the past, and a higher reinforcing effect can be expected compared to conventional strip-shaped reinforcing materials. (3) Soil particles are filled inside the helical reinforcing material, which is made by winding a rod material into a spiral (coiled shape), so that the reinforcing material appears rod-shaped, and the embankment and the reinforcing material become more integrated. It can be expected to have even higher reinforcing effects than conventional strip-shaped reinforcing materials. (4) Since it can be freely deformed in three-dimensional directions, it can fully follow the deformation of the embankment, without creating voids between it and the soil particles, and continuously maintains the specified frictional force with the embankment. It can fully demonstrate its function as a reinforcing material. (5) Despite having the above-mentioned excellent effects, the work of embedding spiral reinforcing material can be done with the same efficiency as when using strip reinforcing material, etc.
The ease of embedding the helical reinforcing material is not inferior.

[Brief explanation of drawings]

Figures 1 to 6 show an embodiment of the reinforced embankment method using a spiral reinforcement according to the present invention, in which Figure 1 is a schematic overall side view, Figure 2 is a schematic overall front view, and Figure 2 is a schematic overall front view. Figure 3 is a perspective view of the spiral reinforcement;
Figures 4 A to C are rear views, side views, and plan views of the wall material, Figures 5 A to M are schematic process diagrams of the construction method, and Figures 6 A and B are schematic overall front views showing other embodiments. It is. Figures 7 and 8 are diagrams showing an example of the experimental results of Example 1, Figure 9 is a perspective view of the experimental model of Experimental Examples 1 and 2, and Figures 10 to 13 are the experimental results of Example 2. FIG. Explanation of symbols, 1: wall material, 1a: back surface, 2: spiral reinforcement, 2a: end, 3: embankment earth, 4:
Connection hole, 5: Rod-shaped material, 6: Reinforcement material attachment part, 6
a: Anchor, 6b: Band-shaped pressing plate, 6c: Nut.

Claims (1)

[Claims] 1. When forming an embankment, first place wall materials approximately vertically on the ground, then place a wall material on the back of the wall material.
Attach one end of a helical reinforcing material made of a bar-shaped material spirally wound, lay the helical reinforcing material on the back side of the wall material in a direction approximately perpendicular to the back surface, and then pour earth and sand onto the helical reinforcing material. The method is characterized in that a helical reinforcing material made of rolled-out rod-shaped material spirally wound is buried in soil and sand, and then compacted to a predetermined soil layer thickness, and this process is repeated to form an embankment. Reinforced embankment method using spiral reinforcement.