JPH02240325A - Construction method of reinforcing earth structure - Google Patents

Abstract

PURPOSE:To increase the effect of reinforcing by laying tension reinforcing members constituted of straight line parts arranged in parallel and arc shaped parts connecting with the straight line parts, scatter earth and sand thereupon, and rolling to form a fill-up layer. CONSTITUTION:Tension reinforcing members A are constituted of a plurality of optional straight line parts 10 arranged in parallel, arc shaped parts 11 to be arranged so that the parts 10 are connected to each other to swell in the direction of the arrow on which resisting earth pressure P is operated, wall panels 12 and nets 13. The earth and sand is spread over the reinforcing members A to be laid, forming a fill-up layer 16 by rolling it, and the operation is repeated to construct a reinforcing earth structure X. According to the constitution, tension is always operated on the arc shaped parts 11, so that the thin quality of the material can resist against higher earth pressure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for constructing a reinforced earth structure using a unique reinforcing material with a small number of members as a tensile reinforcing material buried in an embankment layer. The present invention relates to a method for constructing a reinforced earth structure that exhibits a reliable reinforcing effect even when using soft earth and sand with low frictional force as embankment, has excellent workability, and has small deformation.

[Conventional technology]

BACKGROUND ART In constructing reinforced soil structures (earth retaining structures), a conventional method is known in which soil is piled up while laying a plurality of linear flexible reinforcing materials in layers. (Refer to Japanese Patent Publication No. 44-25174). This method maintains the earth retaining structure only by the frictional force generated between the soil particles and the reinforcing material that comes into frictional contact with them, so it was not suitable for soil with low frictional force. In order to solve this drawback, as shown in FIG. 10(a), a plurality of square pressure-bearing panels 2. Rod-shaped tensile material 1
It has been proposed to use a reinforcement consisting of a wall panel 4 connected to the free end 3 of the wall panel. However, with this method, the wall panel 4
When earth pressure is applied to the bearing panels 2, 2, . . . 2, the stress is concentrated only on the bearing pressure panels 2, 2, . . . 2, so that the bearing panels 2, 2, .

In addition, when installing this reinforcing material, first
．． 2...2 is installed on the embankment layer, soil is poured out from above, and it is compacted and buried in the embankment layer, but at this time, the reinforcing material is deformed by the embankment and compaction, causing the wall surface to deteriorate. The surface of the pressure-bearing panel cannot be held correctly parallel to the panel 4. Therefore, as shown in Fig. 10fb), the embankment layer 5
After digging trenches 6.6...6, accurately placing pressure-bearing panels 2.2...2 in these trenches 6.6...6, and backfilling them, as shown in Figure 10 (C). In this way, reinforcing material is buried in the embankment layer.

However, with this construction method, it is necessary to dig a hole 6 into the embankment layer 5, which complicates the process, and furthermore, the bearing panels 2.
2. The embankment around 2 has become loose. When the embankment is further compacted, the bearing panels 2.2...2 are reduced as shown in Figure 10 (C
As shown in Figure 1, it tends to tilt back and forth or left and right.As a result, the pull-out resistance against the earth pressure acting on the wall baffle 4 is significantly reduced compared to the original design.The reason for this is When the area of the pressure panel 4 is the same, the maximum pullout resistance is obtained when the tension member is positioned perpendicular to the surface of the pressure support panel 4, but if the tension member 4 is tilted with respect to the tension member, This is because the pull-out resistance force decreases significantly as the value increases.

In addition, since the buried soil around the bearing panel 4 inside the groove 6 is difficult to compact, when earth pressure acts on the wall panel 4 and pull-out force acts on the reinforcing material, the bearing panel 4 has the wall baffle 4. As a result, the wall panel 4 is also displaced forward, resulting in an embankment structure with large deformation. Further, even when using a square pressure-bearing panel as shown in FIG. 10, the pressure-bearing panel must be thick in order to withstand the bending stress caused by the resistive structure. For this reason, the above-mentioned known reinforcing materials not only have extremely complicated workability, but also require a large number of members, cause large displacements of the wall surface, and are difficult to obtain a reliable reinforcing effect.

Furthermore, reinforcing materials made by combining rod-like bodies in a mesh-like manner are also known. (Refer to Japanese Patent Publication No. 5,920,821), this reinforcing material is a type of reinforcement material in which the horizontal member acts as a tensile member and the lateral member acts as a pull-out resistor, so it can be effectively used even in soils with low frictional force, and it can be easily used in construction. In such cases, it can be put into use by simply placing it on top of the embankment layer, rolling out the soil, and compacting it.

Further, as shown in FIG. 11 ia+, there is a pressure receiving body 7 having a horizontally elongated upright resistance plate, and a plurality of pressure receiving bodies passing through this pressure receiving body and fixed to the pressure receiving body with screw grooves 8 at desired intervals. A reinforcing material consisting of a rod-shaped tensile material] has also been developed. 9
', Yobukuro Natsutto, 9' is Nando's.

As mentioned above, a reinforcing material in which a plurality of tensile members are connected to a resistor in the transverse direction, such as a reinforcing material in which rod-shaped bodies are combined in a mesh shape or a reinforcing material shown in FIG. 11 fat, has a large pull-out resistance. Moreover, since multiple tensile members in the longitudinal direction are continuous with each other in the transverse direction, they maintain their own shape and have structural strength, so even if they are installed on an embankment as is and the soil is rolled out and compacted, no deformation occurs. Moreover, it has the advantage of being excellent in workability and reinforcing effect. However, the 11th
As shown in Figure ('b), a large bend occurs in the cross member (pressure receiving body 7) due to the resistive earth pressure P resisting the pulling force F, and in order to reduce the bend, the distance between the tensile members 1 in the longitudinal direction is The disadvantage is that it has to be made smaller than necessary,
This results in an uneconomical structure.

Further, FIG. 12 shows an example of a reinforcing material in which a triangular steel rod 1a is attached to the end of the steel rod 1 on the wall panel 4. When such a reinforcing material is used, when earth pressure is applied to the wall panel 4, the steel rod 1a will be distorted and deformed as shown by the dotted line, and as a result, the wall panel 4 will be displaced forward, resulting in a heavily deformed support. It becomes a wall.

-i, what is essentially required for a reinforcing material with transverse members is that the transverse members should have a surface area sufficient to accommodate the required resistance earth pressure, and the longitudinal members should have a surface area sufficient to withstand the earth pressure. It is sufficient to have a cross-sectional area,
If the transverse members are made to have almost no bending, the number of longitudinal and transverse members can be reduced and a very rational reinforcement can be achieved. However, in conventional construction methods, no reinforced earth construction method using reinforcing materials has been developed that focuses on these points.

[Problem that the invention seeks to solve]

Therefore, in order to most rationally create a reinforced soil retaining wall, the inventors of the present invention have found that in order to create a reinforced soil retaining wall in the most rational manner, the longitudinal tensile members should be The present invention has been completed by focusing on a structure that can provide the necessary pull-out resistance without causing almost any bending in the lateral members even if the interval between the tension members is made as large as possible.

The purpose of the present invention is to use a unique reinforcing material with a small number of members as a tensile reinforcing material, thereby achieving a reliable reinforcing effect even when using soft earth and sand with low frictional force as an embankment, and having excellent workability and minimal deformation. The object of the present invention is to provide a method for constructing a reinforced earth structure that improves the drawbacks of the above-mentioned known techniques.

[Means for solving problems]

In order to achieve the above-mentioned object, according to the present invention, a method for constructing a reinforced soil structure is provided, in which a tensile reinforcing material is laid on the ground to be filled, earth and sand is spread on top of the material, and soil is compacted to form an embankment layer. In this case, this tensile reinforcing material consists of a plurality of straight line parts arranged in parallel and an arc-shaped part bridging adjacent comrades of the straight parts, and the arc-shaped part bulges in the direction in which the resistance layer acts. It is characterized by

Hereinafter, the present invention will be explained in detail using the accompanying drawings.

FIG. 1+a+ is a plan view of a specific example of the tensile reinforcing material used in the present invention, which has a straight portion 10 and an arcuate portion 11, and an arbitrary plurality of straight portions 10 are arranged in parallel, The rounded arcuate portions 11 bridge adjacent linear portions 10 and are arranged so as to swell in the direction of the arrow on which the resistive earth pressure P acts. F is the tensile force.

As shown in FIG. 1(b), the tensile reinforcing material A constructed in this manner connects the end 10a of the straight portion 10 to the wall panel 12 with a nut 13 or the like, and
Build the reinforcing structure X as shown in Figure tel.

The above-mentioned tensile reinforcing material A may have a linear portion 10 and an arcuate portion 11 integrally continuous as shown in the first figure, or may have connecting surfaces 11a at both ends as shown in FIG. ,
As shown in FIG. 2 (1), the band-shaped arcuate portion 11 having the lla is bridged between the adjacent straight portions 10 and 10, and is connected to the straight portion 10 by the diagonal 4 at the connecting surface 11a. The arcuate portion 11 may be constructed separately, or the arcuate portion 11 may be a straight portion 10.10 as shown in the first figure.
In this case, the arcuate portion 11 is preferably positioned at the tip of the straight portion 10 as shown in the first figure. Furthermore, a plurality of arcuate portions 11 may be arranged at arbitrary intervals between the straight portions 10 and 10, as shown in FIG. 2. In this case, as shown in FIG. P is received by the plurality of arcuate portions 11.11...11, and the tensile force F increases significantly.Furthermore, since the straight portion 10 is connected by the plurality of arcuate portions 11.11...II,
The tensile reinforcing material A itself has structural strength, so even if the tensile reinforcing material A is laid on the ground 15, soil is thrown out, and the embankment layer 16 is formed by compaction, the tensile reinforcing material A does not retain its shape. Maintenance and workability become easier.

Furthermore, as shown in FIG.
) with a connecting piece 10b at its tip.
0 may be constructed by connecting a plurality of bolts with bolts and nuts 17 at the connecting piece 10b as shown in FIG. 4 [C1, or as shown in FIG. As a material, a strip member is twisted by 90 degrees and held horizontally (sideways) except for the connecting piece 10b, and this straight section 10 is turned into a strip-shaped arcuate section 11 at the vertically (vertically) connecting piece 10b. Further, as shown in FIG. It's okay.

The end portion 10a of the straight portion 10 and the wall panel 12 can be connected by the method shown in FIG. 1 (bl), or by the method shown in FIG.
.

(This may be done by the method shown in bl. In other words, a T-shaped groove 18 is formed in the upper surface 12a of the wall panel 12, and one end 19 of the tensile reinforcing material A is locked in this groove 18 to connect the wall panel 12. Figure 6 tbl may be Figure 6 (al)''
〜=A sectional view.

As for the material of the above-mentioned tensile reinforcing material A, it is suitable to have a rigidity that allows it to maintain its shape when laid on the ground 15 or embankment layer 16, and specifically, it is preferably made of steel. Further, it is possible to use fibers such as FRP, aramid fibers, carbon fibers, etc., which have a large tensile force and have little distortion, and which are impregnated with vinyl chloride or the like as a binder to provide rigidity.

In constructing the reinforced earth structure of the present invention using such a tensile reinforcing material A, first, as shown in FIG. Lay it on the ground 15 so that it swells, and the end 10a
is connected to the wall panel 12 with nuts 13.

Next, as shown in Fig. 7, earth and sand is poured out onto the laid tensile reinforcing material A and compacted to form an embankment layer 16, and the tensile reinforcing material A is further placed on this embanking layer 16 as described above. The end portion 10a is connected to the wall panel 12 with a nut 13.

Furthermore, the above-mentioned operation is repeated to construct the reinforced earth structure X according to the present invention as shown in FIG. 7 (tel).

Note that in FIG. 7 (C1), Y is the active area, that is, the slack area, and in this active area Y, it is more rational for the arcuate portion 11 to swell in the direction of the wall panel 12. In this case, the arcuate portion 11 has the effect of reducing the active earth pressure acting on the wall panel 12.In this region Y, a plate may be used instead of the arcuate portion 11, or a geotextile net or sheet may also be used.

FIG. 8 shows a reinforced earth structure X using a semi-elliptical corrugated wall panel 12, and in this case, it is the same as FIG. 7 (C1) except for the wall panel 12.

Furthermore, as shown in FIG. 9, a round bar-shaped reinforcing material in which straight portions 10 and arcuate portions 11 are integrally continued as shown in FIG. 9+a+ is used as a tensile reinforcing material, and as shown in FIG. As shown in FIG. 9(b), a semi-cylindrical panel formed by stacking thin plates in the vertical direction is used, and each layer 20 of the wall panel 12 arranged in the horizontal direction is
[C] shows a reinforced earth structure X constructed in the same way as shown in FIG.

FIG. 9 fcl is a partial plan view of the ninth open mountain.

[Effect]

The present inventor proposed that the resistance earth pressure P (Fig. 1 f
At, (shown in bl), the final stable shape of the pressure-receiving part almost matches the shape of an arc, so the shape of the pressure-receiving part is formed into an arc from the beginning, and the arc-shaped bulge is used to reduce the resistance to earth pressure. It was discovered that if the tensile reinforcing material is oriented in the direction in which P acts, almost no deformation occurs, and the present invention was completed. That is, the present invention has, as a tensile reinforcing material, a plurality of straight line portions arranged in parallel and an arcuate portion bridging adjacent ones of the straight line portions. By using a reinforcing material that is positioned so as to bulge and hardly causes deformation, it has a reliable reinforcing effect even when using soft earth and sand with low frictional force as an embankment, has excellent workability, and is highly resistant to deformation. Less reinforced earth structures can be constructed.

In addition, the stress acting on the tensile reinforcing material is shown in Figure 1 (al, (b)
), the tensile force F is calculated from the earth pressure acting on the wall panel in the straight section, and the resistance earth pressure P in the arcuate section, so there is no need to consider bending. Even if the interval between the sections is increased, the area of the arcuate section that corresponds to the resistance earth pressure P is sufficient, and therefore the minimum number of tensile reinforcing members is sufficient.

As described above, in the present invention, the shape of the pressure-receiving part of the tensile reinforcing material is arcuate, and this bulge is directed in the direction in which the resistance layer acts, so that almost no bending occurs in the pressure-receiving part, tensile force always acts, and the thin The material can resist large earth pressure.
For example, a reinforced earth retaining wall with a wall height of 10 m is made using the known reinforcing materials shown in Fig. 11, and in this case, the pressure receiving body 7 is made of equilateral angle steel (SS41100 x 100 x Low), and the reinforcing bars in the longitudinal direction are made of 5D30 deformed steel bars. If this is used, in order to keep the bending stress acting on the pressure receiving body 7 within an allowable range, the steel bars in the longitudinal direction must be arranged at intervals of 0.34 m. On the other hand, by making the shape of the pressure receiving body arcuate as in the present invention, and by aligning this bulge in the direction of the resisting earth pressure, the steel bars are raised at the same distance, and the arcuate part has a thickness of 3 m and a length of 3 m. A 101 semicircular steel plate is sufficient, and the amount of material used is reduced compared to the conventional method.

〔Effect of the invention〕

As described above, by using the above-mentioned structure with few members as a tensile reinforcing material, the present invention exhibits a reliable reinforcing effect even if soft earth and sand with low glIr force is used as embankment, and has excellent workability. Therefore, it is possible to construct a reinforced earth structure which has less deformation and which improves the drawbacks of the above-mentioned known techniques.

[Brief explanation of drawings]

Figure 1 (δ), mountain) is an explanatory diagram showing the relationship between the resistance earth pressure and tensile force of the tensile reinforcing material used in the present invention.
FIG. It is an explanatory diagram showing the relationship between the resistance earth pressure and tensile force of the reinforcement material, and is
81 is another example of an arc-shaped part, 4th opening) is an example of a straight part, FIG. 4 tel is a plan view of the tensile reinforcing material in FIG. , (bl
are respectively perspective views of other specific examples of the tensile reinforcing material according to the present invention, FIG. 6(a) is a plan view showing a method of connecting the tensile reinforcing material and the wall panel, and A-A
It is a line sectional view, and FIG. 7 fa), mountain), and fc) are cross-sectional views showing the construction steps of the method of the present invention, and FIG. 8 is a perspective view of another specific example of the structure of the present invention. Fig. 9 (al is a specific example of the tensile reinforcing material according to the present invention, Fig. 9 ('b) is a perspective view of a structure constructed using the same, Fig. 9 fcl
is a partial plan view of Fig. 9 (g)), and Fig. 10 ta+
, (bl, tel are explanatory diagrams showing a known construction process, and FIG. 11(a) is a perspective view of a known tensile reinforcing material.
Figure 1 is an explanatory diagram showing the relationship between the resistance strength and tensile force, and Figure 12 is a plan view of another known tensile reinforcing material. 10... Straight line part, 10a... End part, 11...
・Arc-shaped part, 12... Wall panel, 15... Ground, I6... Embankment layer, 19... One end, A.
...Tensile reinforcing material, X...Reinforced earth structure.

Claims (2)

[Claims] (1) In the method of constructing a reinforced soil structure in which tensile reinforcing material is laid on the ground to be embanked, earth and sand is spread on top of this and compacted to form an embankment layer, this tensile reinforcing material is A method for constructing a reinforced earth structure consisting of a straight line portion and an arcuate portion bridging adjacent linear portions, the arcuate portion bulging in the direction in which resistive earth pressure acts. (2) The method of claim 1, wherein the ends of the straight sections are connected to a wall panel.