JP2007312741A - Structure of base for planting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a base for planting designed to healthily grow a tree planted in a place unsuitable as a planting environment without deteriorating the supporting yield strength of the ground just under an already installed structure. <P>SOLUTION: The structure of the base for planting is obtained as follows. A granular material 50 for forming a porous structure and a base 40 for plant growth to be filled in voids of the granular material assuming the porous structure are used to form a backfilling part so as to have coarse voids only with the granular material 50. The backfilling part and a compaction filled part formed of the base material 40 for the plant growth to be filled in the voids of the granular material are non-uniformly distributed in a hole 13 dug in the underground part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a planting environment in which the above-ground part receives a load such as a pedestrian road and the like, and a tree-planting technique capable of growing healthy trees planted in a place where the underground part is not suitable as a planting environment. It is used as a substitute for hardened hard ground, and relates to the structure of a planting base that can control the growth area of the tree root system while securing the extension area of the tree root system.

Trees have been planted as green space creation in urban areas such as park green spaces and street trees.
In general, tree planting is carried out on the premise of the existence of high-quality soil, but in recent years, planting has been demanded on ground that has been compacted to form the foundation ground for buildings, roads, etc. In order to continue to receive loads from pedestrians and the like, conflicting demands have been made for securing the strength of the ground and securing the elongation of the tree root system.

For example, when planting on street trees planted at the boundary between the roadway and the sidewalk, especially in the sidewalk, underground locations such as electric wires, etc. However, since the elongation of the tree root system that supports the tree is restricted by the planting soil, the tree is placed in a significantly disadvantageous growth environment.
In particular, since the underground buried structure is constructed from the center of the sidewalk to the residential area, the tree root system is forced to extend to the roadway side, and the extension range is remarkably limited.

For this reason, the tree declines, decaying from pruning marks, etc., and if it is remarkable, it causes traffic accidents and personal injury due to fallen trees.
Thus, in the current situation where it is required to secure an extension space of the root system to the sidewalk and the roadway part, establishment of a technology for securing the root system extension area while maintaining the ground strength is a new issue. Yes.
In such a place, the tree root system may expand and enlarge under the sidewalk pavement. With the enlargement of the tree root system, existing structures such as sidewalks may be destroyed, and there is a need for a technology that suppresses and limits the enlargement and elongation of the root system.

The present invention has been made in view of the above points, and the purpose of the present invention is to reduce the supporting strength of the direct foundation board of the existing structure without reducing the planting environment in a place that is not suitable as a planting environment. The object is to provide a planting base structure that can grow healthy.

In order to solve the above-described problem, the structure of the planting base according to the first invention of the present application is a structure of a planting base for planting a tree in a region that receives an overload, and forms a porous structure. And a backfill portion formed so as to have a coarse void formed only by the granular material in the hole excavated in the underground portion, using a granular material for the purpose and a plant growth base filled in the void of the granular material having a porous structure And the compacted filling portion formed by the plant growth base material that fills the voids of the granular material are unevenly distributed.
The second invention of the present application is characterized in that in the structure of the planting base according to the first invention described above, the plant growth base material is formed into a layered shape or a lump-like shape to form a consolidated filling portion.
3rd invention of this application WHEREIN: In the structure of the planting base concerning the above-mentioned 1st invention or 2nd invention, the particle size of a granular material, the particle size of the range close | similar to a tree are coarsened, and the place away from a tree It is characterized by being distributed so as to be thin.

The present invention can obtain the following specific effects.
(1) Since it is possible to secure an extension area of the root system while securing the bearing strength of the direct foundation board of the existing structure, it is adjacent to an existing structure having an underground part where it is difficult to invade the root system of the tree, which could not be achieved so far. It is possible to plant trees in the area.
(2) Structurally ensuring a backfilling part with coarse voids due to granular materials and a compacted filling part for replenishing nutrients by developing fine roots formed with plant growth base materials sufficient to fill the granular voids By doing so, it becomes possible to create a plant growth base that responds quickly to functional differentiation of the root system.
(3) The grain size of the granular material is coarsened in a range close to that of the tree, and distributed so as to become narrower as it goes away from the tree, thereby restricting the root system elongation region and growing the above-ground part of the tree. Can be controlled.
Therefore, a good tree shape can be maintained without performing strong pruning or overpruning.
(4) Planting costs can be reduced because inexpensive materials that are generally distributed can be used as materials for forming the backfill portion and the compacted filling portion.
(5) By controlling the enlargement / extension of the root system, it is possible to protect existing structures such as sidewalk pavements.

  Hereinafter, embodiments of the present invention will be described.

(1) Outline of tree planting base structure FIG. 1 is a model diagram of a tree planting base structure according to the present invention.
In this example, a case where the tree 30 is planted in an area between the roadway 10 and the sidewalk 20 will be described.

  The base structure for planting a tree according to the present invention uses a granular material 50 for forming a porous structure and a plant growth base 40 filled in the voids of the granular material 50 exhibiting a porous structure. A “backfill portion” having a rough void by only 50 and a plant growth base material 40 sufficient to fill the void of the granular material 50 are formed in a layered shape or a lump shape to develop fine roots and replenish moisture. A “consolidated filling portion” is provided.

  In other words, the present invention creates a porous structure by meshing the granular material 50, and fills the voids in the porous structure with the plant growth base 40 so as to extend the root system. Trees planted while securing ground strength in a place that is not suitable as a planting environment (in this example, between the roadway 10 and the sidewalk 20), for example, in which the growth base 40 is formed unevenly in a layered or block shape. It can be grown healthy.

(2) Granular material As the granular material 50, aggregates such as gravel, recycled crushed stone obtained by crushing crushed stone and concrete, crushed brick, crushed tile, volcanic gravel, gravel, crushed block, ALC crushed material, polystyrene foam or the like can be used.
The particle size of the granular material 50 is preferably 10 mm to 250 mm and preferably uniform (single granular).
In the experience so far, the root system can penetrate up to about 1/5 of the diameter of the aggregate, and the average diameter of the granular material 50 to be used is selected depending on how large the tree 30 to be introduced is to be enlarged. .

(3) Plant Growth Base Material The plant growth base material 40 that fills the gaps between the granular materials 50 is organic materials such as bark compost, peat moss, and cocoa dust, in addition to natural soil such as black soil, red soil, red ball soil, and mountain sand. Various commonly distributed materials such as a system soil improvement material or an inorganic soil improvement material such as perlite and vermiculite can be used in appropriate combination.

  Since these materials are generally circulated, a combination according to the nutrient supply capability required for the elongation of the tree root system is appropriately performed depending on the location conditions of the tree 30 and the properties of the granular material 50. This makes it possible to use inexpensive materials and is economical.

(4) Construction method In the construction, the hole 13 is cut between the roadway 10 and the sidewalk 20. When excavating the hole 13, there is a case where a part of the roadway 10 or the sidewalk 20 is removed and excavated so as to include a part of the direct base board.
In addition, the excavation work of the hole 13 may be performed at the same time as the roadway 10 or the sidewalk 20 is created.

Next, the layer of the granular material 50 and the layer of the plant growth base 40 for supplying nutrient water are laid alternately on the bottom of the excavated hole 13 to form a support layer.
And the tree 30 is suspended in the excavated hole 13, and the underground part 31 which is a root pot is installed in a support layer.
Next, in the space formed between the hole 13 and the underground portion 31 of the tree 30, the layer of the granular material 50 and the layer of the plant growth base 40 for supplying nutrient water are alternately laid to withstand pressure planting. Create a foundation.
Moreover, the plant growth base 40 laid between the layers of the granular material 50 may be a mixture in which some granular material 50 is mixed in advance.
As shown in an enlarged view in FIG. 2, the compacted filling portion is filled with the plant growth base 40 between the granular materials 50, and the backfilling portion is located near the compacted packed bed from the plant growth base 40. A layer of only the granular material 50 is formed through a gradually changing portion in which the particle diameter gradually decreases.

When forming the layer of the plant growth base 40 and the layer of the granular material 50, the laying direction does not mean strict horizontal, but may be diagonal, and the layer thickness may be appropriate.
Moreover, the plant growth base 40 and the granular material 50 may be in a lump shape.

When laying the granular material 50 and the plant growth base material 40, it is necessary to perform compaction by compaction using a compactor, a tamper, a roller, or the like.
The elongation of the root system is limited to 23 mm by the Yamanaka soil hardness tester, but it is sufficiently meshed with the granular material 50 and the plant growth base material 40 is sufficiently compacted so as not to exceed this. To do.

  The portion where the plant growth base 40 is laid in layers constitutes a “consolidation packed bed” for developing fine roots and replenishing nourishing water, and the aggregates are brought into contact with each other and engaged with each other. The part in which the granular material 50 is laid so that the skeleton is formed constitutes a “backfill layer (backfilling part)” having a rough void formed only by the granular material 50, and is a place where the support root extends.

In using the granular material 50, the particle size of the granular material 50 can be made coarse in the range close to the tree 30, and the portion away from the tree 30 can be made thin.
When the particle size of the granular material 50 is distributed in this way, the voids can be changed small to restrict the growth of the root system of the tree 30 and thereby prevent damage to existing structures such as sidewalk pavements due to the root system. It becomes.

  The plant growth base 40 falls into the voids of the granular material 50 and tries to penetrate, but the plant growth base 40 is sufficiently compacted so that it does not move into the voids of the granular material 50.

When a large diameter tree is introduced, or when the tree 30 is to be grown large, the size of the granular material 50 near the root is increased.
In this case as well, it is desirable to perform a structural arrangement of the filling portion of the plant growth base material 40 that develops the large voids that elongate the support roots and the absorption roots.
It is appropriate to fill a portion close to the ground, that is, a portion close to the surface layer corresponding to the so-called A layer of natural soil, in a layered shape or a lump shape, and to develop a rough void in a deep portion corresponding to the B layer or C layer.
At this time, when a granular material having a small particle size is used for the surface layer portion close to the ground, the development of root system enlargement can be suppressed, so that destruction of sidewalk pavement and the like can be prevented.

  If the portion close to the ground surface is filled with the plant growth base material 40 in a layered manner, the rough void portion in the underground portion can be kept in a state of high air humidity, and thus the surface of the granular material 50 is wetted. However, the plant root system extends in this part.

  In addition, even if the deep part where the humidity is sufficiently maintained is provided with a portion filled with the plant growth base material 40 appropriately in a layered or lump form, fine roots will develop and invade into natural rock cracks (cracks). The same effect can be obtained, and the growth of the tree 30 having excellent drought resistance is enabled.

(5) Growth environment There is a technology to create a porous structure using coarse aggregate and fill the voids with the plant growth base to extend the tree root system. This is a device for refilling a mixture of materials and filling the gaps uniformly.
This is for the purpose of uniformly extending and growing the plant root system, but the plant growth base material, which is a filler, cannot be filled in the entire gap, and the gap cannot be filled from the gaps in the upper aggregate. It deviates and falls, and in practice, the gap cannot be filled uniformly, and falls and accumulates in the lower gap.
In order to eliminate such inconveniences, a technique has been proposed in which a fibrous material or an adhesive substance is mixed into the plant growth base material to prevent the plant growth base material from deviating.
However, if these methods are used, the materials are limited, which is expensive, the workability is poor, and there is a tendency to gradually deviate downward with the passage of time, and the deviation can be completely prevented. There was a disadvantage that the plant growth base material was shifted downward.

  In addition, if the gap portion is sufficiently uniformly filled with the plant growth base material, a soil environment that is too good in terms of nutrient supply will be formed, so the inclination to the development of absorption roots that vigorously absorb nutrients, and the trees themselves There is a risk that the development of support roots to support the ground will be insufficient, and because the ground part will grow vigorously, the balance with the ground part will be lost and it will be susceptible to strong wind damage due to typhoons, etc. Pruning will start, decay will begin from the pruning trace, and the trees will be weakened.

  On the other hand, the present invention uses a “backfill portion” having a rough void only by the granular material 50 and a plant growth base material 40 sufficient to fill the void of the granular material 50 as a crushing material in a layered shape or a massive shape. In order to develop and replenish nourishment moisture, the supply of nutrients is limited, while suppressing the growth of the above-ground part, a “consolidated filling part” is provided, and a granular material 50 for growing support roots for supporting the tree itself By constructing a large void portion only due to the structure of the plant, a plant growth base that promptly responds to the functional differentiation of the root system is intended.

  In addition, the present invention limits the root hypertrophy growth area by reducing the particle size of the granular material 50 as it moves away from the ground, prevents destruction due to the root hypertrophy of the sidewalk pavement, and grows the above-ground part of the tree 30. It is possible to grow trees that can be controlled and can maintain a tree shape without strong pruning or overpruning.

  Thus, the roots of the trees 30 extending from the root pots of the trees 30 planted in the region between the roadway 10 and the sidewalk 20 are guided in the meshing gap when reaching the underground part of the roadway 10 or the sidewalk 20. Therefore, the root growth of the tree 30 is favorably induced without being inhibited.

  In the present invention, as described above, a large gap formed by meshing the granular material 50 and a portion in which the gap is filled with the plant growth base material 40 in a layered shape or a massive shape are structurally formed.

Thereby, the ground strength is borne by the meshing of the granular materials 50.
Accordingly, since a large number of granular materials 50 are brought into contact with each other and meshed with each other and the skeleton of the guiding base is maintained, the ground that can withstand the load and rolling pressure required for the underground portion of the roadway 10 and the sidewalk 20 is maintained. It is possible to ensure strength.

  In addition, the support of the above-ground part of the tree 30 is supported by placing the support roots in a large gap formed between the granular material groups 50 in which the support roots are made porous, and the absorption of nourishing moisture is between the granular materials 50. The plant growth base material 40 filled in the gaps are made to bear fine roots.

  In addition, it is known that by restricting the root area, it is known that the root system can be restricted to hypertrophy growth, suppressing the hypertrophy growth, preventing destruction of sidewalk pavement, etc., and making the root system extension area constant volume. By adding a restriction, the growth of the tree 30 can be controlled.

  In the example described above, the case where the tree 30 is planted in the area between the roadway 10 and the sidewalk 20 has been described, but the tree 30 can be similarly planted in the area adjacent to the parking lot or the building. it can.

(6) Other Embodiments Other embodiments will be described below. In the description, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 3 shows another embodiment.
In this example, the root extension area (base for pressure-resistant planting) of the shrub 32 and the extension area (base for pressure-resistant planting) of the tree 33 are structurally divided, and the porous is below the root extension area of the shrub 32 of general soil. The root system extension region of the structure tree 33 is created.
At that time, in order to supply oxygen to the root system without inhibiting the hypertrophy growth of the tree 33, it is preferable that the periphery of the trunk of the tree 33 is left hollow.

  In the conventional planting method in which the underground part of the high tree 33 and the underground part of the shrub 32 are arranged side by side in the same stratum, a phenomenon is known in which the shrub 32 dies when abnormal drought or the like occurs. This is presumed to be because the root system development area of the shrubs 32 is small and moisture competition with the tree 33 occurs.

In this example, it becomes possible to reduce drought by dividing the root extension areas of the shrub 32 and the high tree 33, and it is possible to reduce sprinkling curing during drought.
Further, since the root system of the tree 33 can be arranged at a deep underground position, it is possible to further reduce the damage caused by the root system extension and the root system enlargement with respect to the walkway.

  In addition, if a ventilation pipe 70 is disposed in the root system extension area (base for pressure-resistant planting) of the roadway 10, the sidewalk 20, or the shrub 32 as necessary, not only air but also rainwater is underground through the ventilation pipe 70. It is easy for plants and can recharge groundwater. Furthermore, since it is possible to irrigate an aqueous solution containing nutrients through the vent pipe 70 as necessary, it is possible to easily recover the tree vigor.

  In this example, it is possible to secure a root system development space in which the root system extension areas of the shrub 32 and the high tree 33 are different from each other, and therefore it is possible to prevent the occurrence of competition for moisture absorption of the shrub 32 and the high tree 33. It becomes.

FIG. 4 shows another embodiment in which a restriction is applied to the root-based hypertrophic growth area of the tree 30 using the granular material 50 having a fine particle diameter.
In this example, a fine granular material 50 having a fine particle size is provided around the upper portion of the underground portion (root pot) 31 of the tree 30 and the pressure resistant planting base composed of the granular material 50 and the plant growth base material 40. The case where the area 61 is formed is shown.
By forming the restricted area 61 directly under the surface layer portion of the tree 30 and the sidewalk 20 or the roadway 10, it is possible to limit the root system hypertrophy growth area of the tree 30, so the destruction of the sidewalk 20 and the roadway 10 due to the root system enlargement is ensured. Can be prevented.

Model diagram of planting base structure according to the present invention Enlarged view of planting base structure Model diagram of base structure for planting according to another embodiment Model diagram of base structure for planting according to another embodiment

Explanation of symbols

10 ... Roadway 20 ... Sidewalk 11, 12, ... Basic ground 30 ... Tree 31 ... Underground part 32 ... Shrub 33 ... Takagi 40: Plant growth base material 50: Granules 61: Restricted area

Claims (3)

It is a structure of a planting base for planting trees in an area that receives an overload,
A granular material for forming a porous structure;
Using the plant growth base filled in the voids of the granular material having a porous structure,
In the hole excavated in the underground portion, the backfill portion formed so as to have a rough void only by the granular material and the compacted filling portion formed by the plant growth base material filling the void of the granular material are unevenly distributed. Characterized by the
The structure of the planting base.   2. The planting base structure according to claim 1, wherein the plant growth base material is formed into a layered shape or a lump shape to form a compacted filling portion. 3. For planting according to claim 1 or 2, wherein the particle size of the granular material is distributed so that the particle size in a range close to a tree is coarsened and the portion apart from the tree is thinned. The structure of the base.

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