JP4926866B2 - Rehabilitation method and reinforcement structure of aging mortar spray slope and slope stabilization method - Google Patents

Description

  The present invention relates to a regeneration method and a reinforcing structure for an aging mortar spray slope, and further to a stabilization method for a slope.

  Conventionally, mortar spraying has been performed to ensure stability of the slope. Mortar spraying is effective in preventing rainwater penetration and weathering on the slope. FIG. 6A is a cross-sectional view schematically showing a conventional mortar spraying slope. It is the topography where the slope is adjacent to the road 5 and its drainage groove 6, and mortar is sprayed. The mortar sprayer is used for a slope that is stable at the time of design, such as a rock slope.

  However, the influence of groundwater is accumulated over many years, and phenomena such as the formation of cavities 3 and cracks 4 and the protrusion of the slope bottom end 1a occur. These phenomena are considered to be due to the mechanism shown in FIGS. 6 (b1) to (b3). FIG. 6 (b1) is a cross section of a mortar spray slope before aging, and shows a state in fine weather. The broken line indicates the groundwater level surface 7 inside the natural ground 2. FIG. 6 (b2) shows a state during rain. Although the groundwater level surface 7 is rising, since the mortar spray slope is non-permeable, groundwater is not discharged to the ground surface, but flows directly under the mortar spray slope as shown by the solid line arrow. In this state, the mortar spray slope is subjected to water pressure due to groundwater, and at the same time, the groundwater flow that flows directly below the ground granule flows out. When these phenomena are repeated for a long time, the cavity 3 is formed on the back surface as shown in FIG. 6 (6c), and cracks and protrusions are generated. Usually, when performing mortar spraying work, a drain pipe for draining such ground water is installed. However, such drain pipes are almost useless unless they match the spring locations so-called mizumichi, and it is difficult to identify the spring locations and install the drain pipes. Therefore, the mortar spray slope becomes obsolete by being exposed to such vertical fluctuations for many years.

  As the mortar spray slopes age, the mortar falls and collapses with the back ground occur, which is extremely dangerous, so measures are required.

However, it can be said that the aging mortar spray slope has a track record of keeping the slope stable only by thin mortar spray for a long time. In addition, as described above, the mortar spraying work is basically performed on the slope with high stability of the natural ground. Therefore, for such relatively stable slopes, it is used in combination with spraying method frame construction (installation method with a method frame on the slope) and rebar insertion work (spraying method frame construction). Applying a construction method that secures large strength, such as inserting a reinforcing bar in a natural ground and fixing the frame, is expected to be overly safe and wasteful in terms of cost. I must say.
Therefore, it can be said that it is desirable to take measures suitable for the mortar spraying target even when the mortar spraying is aging.

By the way, although mortar is a water-impermeable material, the greening method disclosed in Patent Document 1 uses water-permeable concrete. This tree planting method also repairs the concrete surface, spraying cement paste, mortar and permeable concrete onto the concrete surface, injecting the growth base material into the permeable concrete, and spraying the vegetation substrate onto it It is. In this case, the water-permeable concrete is provided mainly for water retention of vegetation.
JP 2002-146798 A

There are the following two methods for repairing the old mortar spray slope.
(1) Method of demolishing aging mortar and reconstructing mortar sprayer again
(2) A method of using a cavity filling method in which cement paste is poured into the cavity, leaving an aging mortar, and a spray frame method (or a reinforcing bar insertion method in combination).

However, when aging mortar is removed, there are the following problems.
・ It is dangerous because it is a work at high altitude.
-A large protective fence is required to prevent accidents in the vicinity.
・ A large amount of industrial waste is generated by the removed mortar.

  On the other hand, when leaving aging mortar in order not to generate industrial waste, if a reinforcing bar insertion is adopted, a drilling scaffold is required, and if a scaffold is not used, it is necessary to hold the drilling machine in the air. There is a problem that a crane is necessary.

  In any case, since the countermeasure work is carried out on the entire slope, there is a disadvantage that becomes uneconomical. In addition, since the traffic regulation period is long, the impact on the local economy will be significant. In the future, it is expected that many aging mortar spraying surfaces exceeding the service life will occur, and an inexpensive and effective construction method is required.

  In view of the above situation, the present invention is a method for regenerating an aging mortar spray slope, minimizing industrial waste, making it a cheaper construction method, and minimizing traffic restrictions at nighttime etc. The purpose is to realize that it can be released and to ensure sufficient stabilization of the slope. Furthermore, based on the same basic principle, it aims to provide a slope stabilization method that can be used not only with an aging mortar spray slope, but also with a newly performed mortar spray or vegetation base spray.

In order to achieve the above object, the present invention provides the following configurations.
According to the present invention, the method for regenerating an old mortar spray slope is the one or a plurality of sections including the lowermost end part of the mortar spray slope (1) , or the mortar spray provided in a staircase shape. Removing mortar in one or more sections including the lower end of at least one staircase that is part of the slope (1A, 1B, 1C); and permeable concrete (11) for the section from which the mortar has been removed. And a step of constructing the permeable concrete reinforcing body (10) by spraying , wherein the thickness of the permeable concrete reinforcing body (10) is larger than the thickness of the mortar .

  Further, in the step of constructing the permeable concrete reinforcing body in the above-mentioned reclaimed construction method, the first reinforcing bar is disposed in the permeable concrete reinforcing body and the reinforced concrete reinforcing body is fixed to the natural ground. And a second reinforcing bar inserted into the ground is arranged.

The reinforced mortar spray slope reinforcing structure according to the present invention includes one or a plurality of sections including a lowermost end which is a part of the mortar spray slope , or the mortar spray slope provided in a stepped shape ( 1A, 1B, 1C) Permeable water formed by permeable concrete sprayed after mortar removal in one or more compartments including the lower end of at least one staircase that is part of 1A, 1B, 1C) and thicker than the mortar thickness The reinforced concrete reinforcing body, the first rebar disposed inside the permeable concrete reinforcing body, and the first reinforced bar to be fixed to the natural ground and inserted into the natural ground. The second reinforcing bar is provided.

According to the present invention, the slope stabilization method for performing mortar spraying or vegetation base spraying is one or a plurality of sections including the lowest end which is a part of the slope , or the step provided in a staircase shape. A step of constructing a permeable concrete reinforcing body by spraying the permeable concrete to one or a plurality of sections including a lower end which is a part of at least one step which is a part of a slope, and the permeable concrete reinforcing body A mortar spraying process or a vegetation base spraying process on a part other than the section where the mortar is constructed, and the thickness of the permeable concrete reinforcing body is the mortar in the mortar spraying process or the vegetation base in the vegetation base spraying process. It is characterized by being thicker than the thickness of the material .

  Further, in the step of constructing the permeable concrete reinforcing body in the slope stabilization method described above, the first reinforcing bar is disposed inside the permeable concrete reinforcing body, and the reinforced concrete reinforcing body is fixed to the ground. The second reinforcing bar is connected to the first reinforcing bar and is inserted into the natural ground.

  In the regeneration method and reinforcement structure of the aging mortar spray slope according to the present invention, since only a part of the aging mortar is removed, the amount of removal can be minimized and the generation of industrial waste can be suppressed. . In addition, since the construction is not the entire slope, the construction period can be shortened and the traffic regulation period is also short. In addition, the flying prevention fence can be simple.

  Moreover, a water-permeable concrete reinforcement body is built by spraying water-permeable concrete with respect to the division including the lowest end which is a part of slope, or the division of an intermediate height position. Since the water-permeable concrete can permeate water, when the groundwater surface of the natural mountain rises during rainfall, the groundwater can be drained from the natural mountain to the surface. In the present invention, the drainage function is added to a part of the mortar spray slope which has been conventionally non-permeable, so that the drainage is positively drained from the natural ground. Thereby, the rise of a groundwater surface can be suppressed and the hollowing by the fine particle outflow on the back surface of mortar can be prevented. Moreover, since the groundwater pressure acting on the mortar can be eliminated, the occurrence and increase of cracks in the mortar can be suppressed. As a result, the life of the remaining mortar can be extended. In addition, by suppressing the rise of the groundwater surface, the stability of natural ground during heavy rain is improved.

  From the viewpoint of suppressing the rise of the groundwater surface, it is preferable to provide the permeable concrete reinforcing body at a position near the lowest end of the slope. When installed near the bottom of the slope, it is possible to work with relatively small heavy machinery from the road, so there is no need to work at high places and traffic regulation can be simplified. However, it is preferable. Furthermore, the water-permeable concrete can be sprayed, and it is not necessary to use a plate frame, so that it is easy to work even on steep slopes.

  In addition, the permeable concrete reinforcing body is provided with a first reinforcing bar inside, and further provided with a second reinforcing bar that is joined to the first reinforcing bar and inserted into a natural ground, thereby providing a foundation equivalent to a reinforced concrete structure. It becomes a structure with the function of That is, it can counter external forces such as loads from above or sliding loads. As a result, the remaining mortar above the water-permeable concrete reinforcing body can be stabilized and prevented from falling.

  This is particularly effective when the protruding portion at the lowermost end of the aging mortar spray slope is removed and a permeable concrete reinforcement is provided. When the permeable concrete reinforcing body is provided in the section including the lowermost end, the stability of the entire slope can be improved by absorbing the stress concentrated on the lower end of the slope. That is, the permeable concrete reinforcement has a function of receiving the load of the remaining mortar and transmitting it to the natural ground. Thus, the water-permeable concrete reinforcement body of this invention can have an effect equivalent to the retaining wall at the lower part of the slope in a steep cliff, a steep slope collapse prevention area, or the like.

  It is also effective to provide the permeable concrete reinforcing body at an intermediate height where it has been found that water springs out due to spring marks on the surface of the aging mortar. Thereby, generation | occurrence | production of water pressure is prevented and stability improves.

  In addition, the same effect is acquired even if the basic principle of the regeneration method of said aging mortar spraying slope is applied also to the slope which newly performs mortar spraying or a vegetation base material spraying. In this case, a new mortar sprayer or a vegetation base sprayer constructed above the permeable concrete reinforcement is supported and stabilized.

  The permeable concrete reinforcing body constructed in the present invention has an advantage compared to the retaining wall structure or the Futong cage method which is a conventional method for supporting the slope. The retaining wall structure usually has a thickness of about 1m and needs to be installed overhanging on the road side from the target slope, or it must be installed by excavating a natural ground. It is not adopted as. In addition, the Futonkago also requires a considerable installation thickness because the baskets filled with crushed stones and the like are stacked stepwise. On the other hand, since the water-permeable concrete reinforcement body of this invention is based on the spraying construction of water-permeable concrete, it can be implemented by thickness about 5-20cm. Therefore, there is no need to overhang the road or excavate natural ground.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view of a slope that schematically shows one embodiment of a method for regenerating an aging mortar spray slope according to the present invention. FIG. 2 is a front view of the slope of FIG.
The original mortar spraying was performed up to the lowest end (slope) of the slope as shown in FIG. 6 (a). This slope is adjacent to the road 5 and its drain 6. In this aging mortar spraying slope 1, there are cavities 3 on the back of the mortar and cracks 4 on the mortar everywhere. The section of the neighborhood including the lowest end of this mortar spraying slope 1 is removed, and the permeable concrete reinforcement body 10 is built in the section.

  The section where the permeable concrete reinforcing body 10 is built is a part of the aging mortar spray slope 1. In the illustrated example, as shown in FIG. 2, it is a strip-shaped section including the lowermost end, and extends between both ends of the mortar spraying slope 1 in the horizontal direction. The shape of the section in which the permeable concrete reinforcing body 10 is built is not limited to the illustrated example. A plurality of positions may be provided intermittently between both ends of the slope in the horizontal direction. Moreover, it does not need to be a section including the lowermost end, and one or a plurality of places may be provided at appropriate places of the intermediate height.

  In the example of FIG. 2, the height of the water-permeable concrete reinforcing body 10 is partially changed so that the water-permeable concrete reinforcing body 10 is located immediately below the portion where the cracks 4 are concentrated. Thus, you may provide the concrete reinforcement body 10 mainly in the location where it turned out that water springs out by aging.

For example, the water-permeable concrete is a mixture of water and cement at a ratio of about 4: 6 to 3: 7, and crushed stone having a particle size of about 2.5 to 5.0 mm is mixed as a main aggregate. Furthermore, preferably, the occurrence of cracks due to shrinkage is reduced by mixing vinylon short fibers to increase bending and tensile toughness. The solidified water-permeable concrete has a pore structure with continuous voids of 15% or more with a void diameter of about 1 mm. Due to this pore structure, it has a hydraulic conductivity (1 × 10 ⁻¹ cm / second or more) equivalent to a gravel layer. The permeability coefficient of this permeable concrete is much larger than the permeability coefficient of natural ground (10 ⁻² to 10 ⁻³ cm / sec). Therefore, when the weather is fine, the back surface water can be sucked up by capillary action, and when it is raining, the permeated water from the back ground can be permeated to the surface or guided through the internal continuous gap in the direction of the buttock.

  FIG. 3 is an enlarged cross-sectional view showing a preferred embodiment of the water-permeable concrete reinforcing body 10 shown in FIG. The thickness of the permeable concrete reinforcing body 10 constructed by spraying the permeable concrete 11 is, for example, 5 to 20 cm, and is preferably thicker than the mortar spraying thickness (typically about 8 cm). The height of the permeable concrete reinforcing body 10 is appropriately set in consideration of the aging degree of the mortar, the drainage amount, the support strength, and the like.

  Inside the permeable concrete reinforcing body 10, a plurality of first reinforcing bars composed of vertical bars 12a and horizontal bars 12b are arranged. Furthermore, the 2nd reinforcing bar 13 is arrange | positioned. The second reinforcing bar 13 may be, for example, a reinforcing bar used for a reinforcing bar insertion work, and a lock bolt used for a locking bolt work is preferable in terms of strength. The head of the second reinforcing bar 13 is coupled to the first reinforcing bar 12 a or 12 b, and the main body portion is inserted into the natural ground 2. The length of the main body is appropriately set according to the required tensile strength.

  When the pressure receiving plate 14 is provided in the vicinity of the head portion of the lock bolt, the pressure receiving plate 14 is installed on the slope and the tension is applied to the lock bolt, whereby the lock bolt is more firmly fixed. Thereby, the water-permeable concrete reinforcement body 10 becomes a structure equivalent to a reinforced concrete, and has a function as a solid foundation.

  The arrangement density of the first reinforcing bars 12a and 12b and the second reinforcing bars 13 is appropriately set according to the required strength. In addition, these reinforcing bars are preferably subjected to rust prevention treatment such as epoxy-coated reinforcing bars.

  In addition, the penetration of rainwater can be prevented by spraying a thin waterproof material on the surface of the water-permeable concrete reinforcing body 10. The thickness of the waterproof material on the surface is set so as not to hinder drainage from the natural ground side. Further, the water-permeable concrete reinforcing body 10 can be sufficiently drained even through its internal pore structure. By coloring the waterproof material sprayed on the surface, a scenic effect can be obtained.

The process of installing the permeable concrete reinforcement body 10 shown in FIG. 3 with respect to the aging mortar spraying slope is as follows.
First, a part of the aging mortar is removed to expose the slope. Next, the first reinforcing bars 12 a and 12 b are installed, and the second reinforcing bars 13 are coupled to the first reinforcing bars 12 a and 12 b and are fixed to the natural ground 2. Then, the water-permeable concrete reinforcement body 10 is constructed by spraying water-permeable concrete by a predetermined thickness.

  FIGS. 4A1 to 4A3 are cross-sectional views schematically showing the mechanism of the effect of the reinforcing structure by the water-permeable concrete reinforcing body 10. FIG. 4 (a1) is a cross section of a mortar spraying slope provided with the permeable concrete reinforcing body 10, and shows a state in fine weather. The broken line indicates the groundwater level surface 7 inside the natural ground 2.

  FIG. 4 (a2) shows a state during rainfall. The groundwater level surface 7 rises during rainfall, but is drained through the permeable concrete reinforcing body 10 as indicated by the solid line arrow. Therefore, the groundwater level surface 7 is higher than the conventional example shown in FIG. 6 (b2). The rise of is small. The drainage path through the permeable concrete reinforcing body 10 includes a path that passes through the surface of the permeable concrete reinforcing body 10 and flows down, and a path that flows down inside the permeable concrete reinforcing body 10. In any case, the flow of water behind the aging mortar is reduced, and the amount of drainage from the permeable concrete is greater than the amount of precipitation flowing from the surface, so no water pressure is generated and the aging mortar I will not receive. Thus, the water-permeable concrete reinforcement body 10 by this invention provides an effective drainage function with respect to a part of conventional mortar spraying slope which was non-water-permeable entirely.

  Therefore, when the groundwater level surface 7 is lowered again as shown in FIG. 4 (a3), the state of the remaining aging mortar is maintained unchanged from that before the rain. That is, the expansion of existing cavities and cracks and the generation of new cavities and cracks can be prevented.

  5 (a) and 5 (b) are sectional views of slopes schematically showing another embodiment of the present invention. In this embodiment, as shown in FIG. 5 (a), the original mortar spraying slopes 1A, 1B and 1C are provided stepwise. A small drainage groove 8 is embedded in each of the stairs. And the cavity 3 arises in the back surface of the mortar spraying slope 1B, the crack 4 arises in 1C of mortar spraying slopes, and it has become old.

  In this case, as shown in FIG.5 (b), the mortar of each mortar spraying slope 1B and 1C vicinity part of each lower end is removed, and water-permeable concrete reinforcement bodies 10A and 10B are each constructed. The mortar spray slope 1A remains as it is because no abnormality has occurred. Thus, you may provide the water-permeable concrete reinforcement body 10 in a part of slope and the position of intermediate height. The “intermediate height” is not particularly limited, but in order to secure to some extent the effects of suppressing the rise of the groundwater surface and reducing the groundwater pressure as shown in FIG. 4, the height H of the entire target slope is 80 It is preferable to provide the permeable concrete reinforcing body 10 at a position lower than%.

As described above, the present invention mainly focuses on the regeneration method of the aging mortar spray slope and its reinforcing structure. However, it is also possible to apply the same basic principle to a new mortar spraying or vegetation base spraying.
For example, for a slope where slope stabilization work is applied for the first time, or against a slope where all existing slope stabilization work has been removed, a permeable concrete reinforcement body is provided in the section including the lowest end of the slope face. The mortar spraying or vegetation base spraying is performed on the slope of the other parts. In this case, the mortar spraying work or the vegetation base material spraying work is stably supported, and at the same time, the instability of the natural ground due to the rise of the groundwater surface at the time of rainfall can be suppressed. As a result, compared to the case without permeable concrete reinforcement, the life of the mortar spraying is longer, the stability of the slope is improved in the vegetation base spraying, and the road growth is improved by the growth of the plant. There is no obstacle.

It is sectional drawing which shows typically the slope which applied the regeneration construction method of the aging mortar spraying slope by this invention. It is a front view of the slope of FIG. It is an expanded sectional view which shows the suitable Example of the water-permeable concrete reinforcement shown in FIG. (a1)-(a3) is sectional drawing of the slope which showed typically the mechanism of the effect of the reinforcement structure by a water-permeable concrete reinforcement body. (a) (b) is sectional drawing of the slope which shows another Example of this invention typically. (b1)-(b3) is sectional drawing of the slope which showed typically the aging mechanism of the conventional mortar spraying slope.

Explanation of symbols

1, 1A, 1B, 1C Aging mortar spray slope 2 Ground 3 Cavity 4 Crack 5 Road 6 Road drain ditch 7 Ground water surface 8 Slope small drain ditch 10, 10A, 10b Permeable concrete reinforcement 11 Permeable concrete 12a , 12b Reinforcement 13 Reinforcement (lock bolt)
14 Pressure plate

Claims (5)

A rehabilitation method for the aging mortar spray slope,
One or a plurality of sections including a lowermost end which is a part of the mortar spraying slope (1) , or at least one part of the mortar spraying slopes (1A, 1B, 1C) provided stepwise. Removing mortar in one or more compartments including the bottom of two stairs ;
And constructing the permeable concrete reinforcement (10) by spraying the permeable concrete (11) on the section from which the mortar has been removed ,
A method for regenerating an aged mortar spraying surface, characterized in that the thickness of the water-permeable concrete reinforcement (10) is larger than the thickness of the mortar.   In the step of constructing the water permeable concrete reinforcing body, the first reinforcing bars (12a, 12b) are disposed inside the water permeable concrete reinforcing body, and the permeable concrete reinforcing body is fixed to the ground. 2. A method for regenerating an aging mortar spray slope according to claim 1, characterized in that a second reinforcing bar (13) connected to the reinforcing bar of 1 and inserted into the ground (2) is arranged. It is a reinforcing structure for the aging mortar spray slope,
One or more sections including the lowest end which is a part of the mortar spray slope , or at least one staircase which is a part of the mortar spray slope (1A, 1B, 1C) provided in a staircase shape A permeable concrete reinforcement formed of permeable concrete sprayed after removal of the mortar in one or more compartments including the lower end and formed thicker than the thickness of the mortar ;
A first rebar disposed inside the permeable concrete reinforcement;
A structure for reinforcing an aging mortar spray slope comprising a second rebar coupled to the first rebar and inserted into the ground to fix the permeable concrete reinforcing body to the ground. . Stabilization method of slope to perform mortar spraying or vegetation base spraying,
Permeability of one or more sections including the lowermost end that is a part of the slope, or one or more sections including the lower end of at least one step that is a part of the slope provided in a staircase shape Building a water permeable concrete reinforcement by spraying porous concrete;
And a step of performing a mortar spraying work or a vegetation base spraying work on a part other than the section where the water-permeable concrete reinforcing body is constructed ,
The slope stabilization method according to claim 1, wherein the thickness of the permeable concrete reinforcing body is greater than the thickness of the mortar in the mortar spraying or the thickness of the vegetation base in the vegetation base spraying .   In the step of constructing the permeable concrete reinforcing body, a first reinforcing bar is disposed inside the permeable concrete reinforcing body, and is coupled to the first reinforcing bar to fix the permeable concrete reinforcing body to a natural ground. The slope stabilization method according to claim 4, wherein a second reinforcing bar that is inserted into a natural ground is disposed.

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