JPH0827794A - Slope reinforcement method and embankment construction method - Google Patents

Abstract

(57) [Summary] [Purpose] To form a slope reinforcement layer that has sufficient proof strength against slippage, allows the introduction of vegetation, and is easy to construct. [Structure] The amount of cement mixed should be 30 to 1 so that the soil hardness index is 27 mm or less as measured by the Yamanaka soil hardness meter.
Poorly mixed soil cement S and continuous long fibers 5 of 00 kg / m ³ are conveyed by independent pipelines 4 and 9, respectively, and inclined surface M
Then, the slope reinforcing layer 10 having a predetermined width is formed along the inclined surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slope reinforcement method which has a sufficient proof against slippage, can introduce vegetation and is easy to construct, and a banking construction method using the slope reinforcement method.

[0002]

2. Description of the Related Art Conventionally, as a slope reinforcing and stabilizing method, when the slope is almost vertical, various retaining wall structures such as an inverted T type and a gravity type are constructed, but a slope gradient to some extent. If the above can be secured, a structure such as a leaning retaining wall or a block stacking retaining wall is constructed as a relatively simple structure.

On the other hand, in recent years, by using a dedicated machine, sand and continuous fibers such as polyester are simultaneously sprayed and three-dimensionally mixed, so that pseudo adhesive force and deformation resistance are applied to the sand which originally has no adhesive force. Reinforced earthwork method with good properties has been put to practical use. Originally, the shear strength of granular soil such as sand is governed by the internal friction angle, but by incorporating continuous fibers, the sand particles and continuous fibers are frictionally bonded to each other, and as a result, the continuous fibers become sandy. When the movement of particles is impeded and deformed by receiving a force, the continuous fiber acts as a tensile reinforcing material, a binding force is generated according to the tensile force, and a pseudo adhesive force is given to the reinforced soil. Moreover, since it is reinforced with continuous fibers at the same time, it has an advantage that yield strain increases.

[0004]

However, when constructing a leaning retaining wall or the like as slope reinforcement, since the material is concrete, vegetation is impossible even if it has sufficient earth pressure resistance. In addition, it requires backfilling and formwork for placing the concrete, which requires time, labor and construction cost in construction.

Further, according to the above-mentioned reinforced earth construction method, it is possible to construct a structure such as a leaning retaining wall even with granular soil such as sand, but in the first place, the sand is given a pseudo adhesive force. Since it is a soil structure, it is not much different from the case of constructing the slope with sandy soil or cohesive soil that has adhesive strength from the beginning. Therefore, even if mixing of continuous fibers is effective in preventing runoff and collapse due to rainwater, etc., its application range can be applied only to the case of the embankment height that can be originally considered as the embankment slope. is there.

In view of the above-mentioned problems, the main object of the present invention is to provide a slope reinforcement method which has a sufficient proof strength against slippage, is capable of introducing vegetation and is easy to construct, and embankment construction using the same. It provides a construction method.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a cement content of 3 so that the soil hardness index is 27 mm or less as measured by a Yamanaka soil hardness meter.
It is characterized in that poorly mixed soil cement of 0 to 100 kg / m ³ is conveyed by air and sprayed on a sloped ground surface to form a slope reinforcement layer having a predetermined width along the sloped surface. In this case, continuous long fibers are preferably sprayed together with the poorly mixed soil cement. In addition, after forming the block-shaped slope reinforcement, insert it with the upper portion of the splice joint reinforcement protruding from the upper surface of the slope reinforcement, and then insert the slope reinforcement further above the slope reinforcement. It is preferably formed by spraying.

Further, in the embankment construction method using this method, the soil hardness index is 2 as measured by a Yamanaka soil hardness meter.
The amount of cement mixed is 30 to 100 so that it is 7 mm or less.
Air transporting poorly mixed soil cement (kg / m ³⁾ and spraying it on the base of the planned embankment slope to form a block-shaped slope reinforcement, and then until the same level on the back side of this slope reinforcement. The embankment is performed to form the first slope reinforcement layer and the embankment layer, and thereafter, this step is sequentially repeated to form the slope reinforcement layer and the embankment layer having a predetermined height. In this case, continuous long fibers are preferably sprayed together with the poorly mixed soil cement. In addition, after forming the block-shaped slope reinforcement, insert it with the upper portion of the splice joint reinforcement protruding from the upper surface of the slope reinforcement, and then insert the slope reinforcement further above the slope reinforcement. It is preferably formed by spraying.

Further, in these cases, before forming the slope reinforcing layer, by arranging reinforcing reinforcing bars in the inclined direction in advance in the forming portion, the insertion of the splice joint reinforcing material to be inserted halfway can be omitted. can do. Further, a vegetation base layer is formed on the surface side of the slope reinforcing layer. In addition, by making a root system penetration hole in the slope reinforcement layer and filling the root system penetration hole with a vegetation base material or a rod-shaped fertilizer, it is possible to prevent the plant root system from entering the slope reinforcement tank. It can be promoted and promote the growth of plants.

In the case of the embankment construction method, an embankment reinforcement layer formed by spraying continuous long fibers together with poorly mixed soil cement is formed between each embankment layer and the embankment reinforcement layer and slope reinforcement layer. By embedding a reinforcing material whose one end is fixed to the slope reinforcement layer, the embankment itself is reinforced and the stability against slippage can be improved.

[0011]

According to the present invention, poorly mixed soil cement having a cement content of 30 to 100 kg / m ³ is conveyed by air so that the soil hardness index is 27 mm or less as measured by the Yamanaka soil hardness meter, and the soil is sloping. Spray along the board and form a slope reinforcement layer with a predetermined width along the slope. The soil hardness index is defined here because it is difficult for the roots of the plant to grow when the soil hardness index exceeds 27 mm. Therefore, in the present invention, the amount of cement mixed is set to ³⁰ to 100 kg / m ^{3 although} it varies depending on the soil pressure due to the state of the slope or the embankment and the strength of the earth and sand used. If the amount of cement mixed in is less than 30 kg / m ³ , the strength of soil cement is insufficient and slip resistance cannot be obtained. Also, 1
If it exceeds 00 kg / m ³ , the strength is 15 in uniaxial compressive strength.
~ 20kgf / cm ² or more, soil hardness index exceeds 27mm, which inhibits root system invasion of vegetated plants,
Difficult to grow plants.

When vegetation is examined from the soil hardness index,
Generally, if the soil hardness index is 10 mm or less, it is not preferable because there is a risk of slope collapse and runoff.
In the present invention, since the continuous long fibers are mixed, it is possible to sufficiently counter erosion by wind and rain,
In particular, it is not necessary to specify the lower limit value.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments.
First, in the case of slope reinforcement according to the present invention, the soil hardness index should be 27 mm or less with respect to the embankment slope, the cut slope or the slope of the natural ground M as measured by the Yamanaka soil hardness meter. Then, poorly mixed soil cement having a cement mixture amount of 30 to 100 kg / m ³ is conveyed by air, and preferably continuous long fibers 5 are simultaneously sprayed together with the poorly mixed soil cement to form a slope reinforcing layer 1 having a predetermined width.

For example, the usual amount of sand, specifically 30
When mortar or concrete mixed with 0 to 450 kg / m ³ of cement is used as the slope reinforcement material, the constructed leaning retaining wall is rigid and can have high slope stability. However, of course, it is not suitable for vegetation and the mortar or concrete surface is exposed.

On the other hand, for example, by incorporating 0.2% by weight of continuous long fibers into sand which originally has no adhesive strength, pseudo-adhesion of about 1.0 kgf / cm ² due to the entanglement of sand and continuous long fibers. It is possible to apply force, but it is not possible to increase the adhesive force by mixing more continuous filaments. Therefore, in the present invention, the amount of cement mixed is 30
By using the poorly mixed soil cement limited to -100 kg / m ³ as the slope reinforcing material, the adhesive strength corresponding to the cement mixing amount is further imparted, and the shear strength can be improved. Normally, when the unit cement amount C for spraying soil cement is 50 kg / m ³ , q _U (uniaxial compressive strength) = 4.0 kgf / cm ² can be expected. Due to differences in mixing accuracy between site and laboratory experiments, variations in soil quality, variations in water content, construction conditions, etc., it is likely that the uniaxial compressive strength will vary in the case of actual work, so the field / indoor strength ratio k should be 0. Even if corrected as 0.5, the adhesive force c _U is c _U = 1/2 × q
_{From U} × k, an increase in adhesive strength of about 1.0 kgf / cm ² can be expected, and a slope reinforcing layer having high resistance to sliding can be constructed.

The poorly mixed soil cement and continuous filaments can be sprayed by, for example, the method shown in FIG. Reference numeral 1 denotes a spraying nozzle, and the poorly mixed soil cement S is mixed with water, cement and sand in a predetermined mixing ratio in a spraying machine 3, and is pressure-fed by a pressure-feeding pipe 4, and is sprayed onto the inclined ground surface from the spraying nozzle 1 at the tip. Attached and the leaning retaining wall is constructed. On the other hand, continuous long fibers 5 such as polypropylene are unrolled from the rolled cheese 6 wound in a cone shape, for example, introduced into a yarn feeder 7 and compressed by a compressor 8 through a fiber pressure-feeding hose 9 at the tip thereof. It is possible to join the poorly mixed soil cement S in one part of the spray nozzle and spray it at the same time. It is also possible to mix an organic material such as fertilizer, bark compost or peat moss together with the poorly mixed soil cement S. In this case, the amount of organic material mixed is 3 by volume.
It is preferably about 10% and about 45 to 150 kg / m ^{3 by} weight.

Further, as the continuous filament, a bulky processed yarn is preferably used. Examples of the material include various series of resins such as polyester, polyamide, acrylic, polyvinyl alcohol, polypropylene, polyethylene, polyvinyl chloride, polyvinylidene chloride, and acetate. It is also effective to use a conjugate yarn, especially a laminated yarn. When a bulky yarn of this type is used, the frictional area with the compressed air is increased when the fiber is fed under pressure, the transportability is further enhanced, and the fibers are easily separated after spraying, and the adhesiveness with the spray material is also enhanced. The number of crimps of the bulky processed yarn is 50 to 9 per 25 m of JIS L 1015.
000, particularly preferably 100 to 3000. Further, as the bulky processed yarn, rather than using one thick fiber of total denier, a fiber of 50 to 1000 d (denier) is used.
It is preferable that about 2 to 40 bundles are bundled and sprayed because they are more uniformly dispersed on the sprayed target surface and the stability of the substrate is excellent. The amount of continuous long fibers mixed is preferably 0.1 to 0.5%, and particularly preferably 0.2 to 0.3%, based on the weight of poorly mixed soil cement. If it is less than 0.1%, sufficient adhesive strength cannot be obtained, and if it exceeds 0.5%, the adhesive strength is not improved so much as to be commensurate with the mixed amount.
By the way, the pressure of the compressed air is preferably ² to 15 kg / cm ² , and the flow rate is preferably 0.3 to 5 liters / minute.

There are various conceivable modes of forming the slope reinforcing layer 10. First, as the first mode, as shown in FIG. 2, the poorly mixed soil cement S and continuous long fibers are formed on the surface portion of the inclined surface M. 5 are simultaneously sprayed and stacked to form the slope reinforcing layer 10 on the slope M. The width B of the slope reinforcing layer 10 is preferably in the range of approximately 30 to 150 cm.

Next, a vegetation base layer 11 is formed by spraying on the surface side of the formed slope reinforcing layer 10. By mixing the continuous filaments 5 also in the vegetation base layer 11, the adhesive force of the vegetation base layer 11 is increased and erosion due to rainwater or the like is prevented. As vegetation base materials, for example, organic soil conditioner peat moss and bark compost are used as the main raw materials, and polymer and inorganic soil conditioners, slow-acting chemical fertilizers, etc. are added to the growth base materials and other advanced chemical conversion treatment. fertilizer,
A mixture of the binder and seeds is sprayed by the spraying machine 3.
In the vegetation base layer 11, spun yarn made of single fiber may be used. By using a part of the super absorbent fiber as one component of the spun yarn, it is possible to improve the germination property and the growth property thereof. This combined use is possible by preparing as many wound cheeses 6 as the required number of such spun yarns and bundling them with other processed yarns.

Next, when the slope is long in the horizontal direction or the inclined direction, the forming method shown in FIG. 3 is preferably used as a second example. Slope reinforcement layer 10 shown in the same figure
Is air-conveying poorly mixed soil cement S, and spraying it on the base end portion of the slope M while mixing the continuous long fibers 5 therein, and having a predetermined width / height, specifically, a width of 30 cm to 150 cm.
The height is 30 to 150 cm, and the block-shaped slope reinforcement S ₁ of the first stage is formed. Next, on the upper surface of the first step slope reinforcement S ₁ , along the slope direction, for example, 30 to
After inserting the reinforcing bar 12 of 100 cm so that the upper half of the reinforcing bar 12 projects, the block-shaped slope reinforcing member S ₂ of the next second stage is inserted.
To form. In this manner, while inserting the reinforcing steel or the like hitting joint boundary of each stage, third stage, fourth stage slope reinforcement S _3, piled up S _4, finally many stages slope reinforcement of The slope reinforcing layer 10 made of S ₁ , S ₂ ... Is formed. As the reinforcing bar to be inserted into the connecting boundary portion of each step, other than the reinforcing bar, one that can obtain a predetermined tensile force, for example, a strip-shaped plate plate, an angle, or a shaped steel material such as H steel can be used. Regarding the insertion interval of the reinforcing bars 12, an arc slip analysis is performed, and only the amount to compensate for the insufficient shear strength is inserted, but if it is too dense it will interfere with the construction, so the basic pitch is 0.3 to 1.0 m. , Preferably 0.5 to 1.0 m,
It is desirable to deal with this by increasing the cross-sectional size.
In addition, when inserting the reinforcing bar 12, as shown in FIG.
The slope reinforcing layer 10 can be formed by stacking the slope reinforcing bodies S ₁ , S ₂ ... After fixing the continuous reinforcing bars 13 in the inclination direction by means of 4.

As the drainage treatment in the slope reinforcing layer 10, as shown in FIG. 5, the filter mat 15 is laid between the back surface of the slope reinforcing layer 10 and the sloped ground surface M, and the filter perforated pipe 16 is provided. The water is collected by the drainage pipe 17 disposed through the slope reinforcing layer 10 and discharged. It is suitable that the drainage pipes 17 are arranged at intervals of about 1 to 3 pipes / m ² . In addition, after forming the slope reinforcements S ₁ , S _2, ..., As shown in FIG.
Root system penetration holes 10a, 1 for slope reinforcements S ₁ , S _2, ...
It is also possible to bore 0a ... And insert the vegetation base materials 18, 18 ... into it. As a result, the penetration of the plant root system into the slope reinforcements S ₁ , S _2, ... Is promoted.

In this case, the root system penetration holes 10a, 10a
It is also possible to insert fertilizer in the direction of ... to promote plant growth.

On the other hand, as an embankment construction method utilizing the slope reinforcement method, as shown in FIG. 7, poorly mixed soil cement S having a cement content of ^{30 to} 100 kg / m ³ is conveyed by air, and continuous long fibers are fed thereto. 5 is mixed and sprayed on the base of the planned embankment slope to form a predetermined width and height to form the first block-shaped slope reinforcement S ₁ . Next, an embankment material is laid on the back side of the slope reinforcement S ₁ of the first stage and compacted to form the embankment layer N ₁ of the first stage.
Next, after inserting a reinforcing bar 12 of, for example, 30 to 100 cm into the upper surface of the slope reinforcement S ₁ of the first stage along the slope direction so that the upper half thereof protrudes, the next second stage The slope reinforcement S ₂ is formed. Then, an embankment material is laid on the back side of the slope reinforcement S ₂ and compacted to form a _second embankment layer N ₂ . In this manner, the third and fourth slope reinforcements S _3,
S ₄ ... and embankment layer N _3, N ₄ ... of the stacked by finally construct a embankment reinforced by the inclined surface reinforcing layer 10.

In the embankment construction method, for example, as shown in FIG.
As shown in FIG. _2, the embankment reinforcing layers 20, 20 ... In which continuous continuous fibers 5 are sprayed together with the poorly mixed soil cement S are formed between the embankment layers N _1, N ₁ ...
0, 20 ... And each slope reinforcement S _1, S _2, ... Continuation can increase resistance moment with respect to slip by the embankment reinforcement layers 20, 20 ,. can do. In addition, since the poorly mixed soil cement S forming the embankment reinforcing layer 20 has excellent water permeability, a drainage effect can be expected at the same time.

Further, inside the embankment reinforcement layer 20, a head 21a at one end is fixed to the slope reinforcement layer 10 as a reinforcement member 21.
By embedding, it is possible to further increase the stability against slippage.

[0026]

As described above in detail, according to the present invention, it is possible to form a slope reinforcing layer which has a sufficient proof stress against sliding and which can introduce vegetation and can be easily constructed.

Further, when the embankment is formed by utilizing this slope reinforcement method, it is possible to obtain high stability against sliding.

[Brief description of drawings]

FIG. 1 is a diagram showing how a poorly mixed soil cement and continuous filaments are sprayed.

FIG. 2 is a vertical cross-sectional view showing an example of forming a first slope reinforcing layer.

FIG. 3 is a vertical sectional view showing an example of forming a second slope reinforcing layer.

FIG. 4 is a vertical cross-sectional view showing another example of reinforcing bar arrangement.

FIG. 5 is a vertical cross-sectional view showing an example of attachment of drainage equipment.

FIG. 6 is a vertical cross-sectional view of an example in which a root system penetration hole is formed in a slope reinforcing layer.

FIG. 7 is a vertical cross-sectional view of an embankment example formed by the embankment forming method of the present invention.

FIG. 8 is a vertical cross-sectional view of a case where an embankment reinforcement layer is formed.

FIG. 9 is a vertical cross-sectional view when a reinforcing material is embedded in the embankment reinforcing layer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Spraying nozzle, 3 ... Spraying machine, 4 ... Pressure feeding pipe, 5 ... Continuous filament, 6 ... Winding cheese, 7 ... Yarn feeding device, 8 ... Compressor, 9 ... Fiber pressure feeding hose, 10 ... Slope reinforcement layer, 10
a ... Root system penetration hole, 11 ... Vegetation base layer, 12/13 ... Reinforcing bar, 14 ... Anchor pin, 15 ... Filter mat, 1
6 ... Filter perforated pipe, 17 ... Drainage pipe, 18 ... Vegetation base material, 20 ... Embankment reinforcement layer, 21 ... Reinforcement material, S ... Poor mixture soil cement

Claims (11)

[Claims] 1. The amount of cement mixed is 30 so that the soil hardness index is 27 mm or less as measured by a Yamanaka soil hardness meter.
A slope reinforcement method characterized in that a poorly mixed soil cement of 100 kg / m ³ is conveyed by air and sprayed on a sloped ground surface to form a slope reinforcement layer of a predetermined width along the sloped surface. 2. The amount of cement mixed is 30 so that the soil hardness index is 27 mm or less as measured by a Yamanaka soil hardness meter.
Poorly mixed soil cement of ~ 100 kg / m ³ is conveyed by air and sprayed on the base of the planned embankment slope to form a block-shaped slope reinforcement, and then the same height is set on the back side of this slope reinforcement. Embankment is carried out to form the first slope reinforcement layer and the embankment layer, and then the slope reinforcement layer and the embankment layer having a predetermined height are formed by sequentially repeating this step, thereby forming a embankment. . 3. The slope reinforcement method and embankment construction method according to claim 1, wherein continuous long fibers are sprayed together with the poorly mixed soil cement. 4. Spraying is started from the slope end of the sloping ground surface,
After forming the block-shaped slope reinforcement, insert it with the upper part of the splice reinforcing member protruding from the upper surface of the slope reinforcement, and then insert the block-shaped slope reinforcement further above the slope reinforcement. The slope reinforcement method according to claim 1, wherein the slope reinforcement layer is formed by repeating a step of forming by spraying. 5. A block-shaped slope reinforcing member is formed, and then the upper portion of the splice joint reinforcing member is inserted in a protruding state from the upper surface of the slope reinforcing member, and then a slope is further provided on the upper side of the slope reinforcing member. The embankment construction method according to claim 2, wherein the reinforcing body is formed by spraying. 6. The reinforcing reinforcing bars are arranged in the inclined direction in advance at the formation portion of the slope reinforcing layer before the slope reinforcing layer is formed.
Slope reinforcement method and embankment construction method described. 7. The slope reinforcement method and embankment construction method according to claim 1, wherein a vegetation base layer is formed on the surface side of the slope reinforcement layer. 8. A root system penetration hole is formed in the slope reinforcing layer,
The slope reinforcement method and embankment construction method according to claim 7, wherein the root system intrusion holes are filled with a vegetation base material. 9. A root system penetration hole is formed in the slope reinforcing layer,
The slope reinforcement method and embankment construction method according to claim 7, wherein rod-shaped fertilizer is filled in the root-system intrusion holes. 10. An embankment reinforcing layer formed by spraying continuous long fibers together with poorly mixed soil cement between each embankment layer, and the embankment reinforcing layer and slope reinforcement layer are continuous. Item 2, 3, 5-8 embankment construction method. 11. The embankment construction method according to claim 10, wherein a reinforcing material having one end fixed to the slope reinforcement layer is embedded inside the embankment reinforcement layer.