JPH0647827B2 - Rock reinforcement method - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a natural ground reinforcement method for protecting natural ground.

[Conventional technology]

FIG. 15 is a sectional view for explaining the outline of a conventional ground reinforcement method of this type disclosed in, for example, Japanese Patent Publication No. 53-46361. In the figure, (1) is a ground on the slope to be reinforced, (1a) is a groove formed shallowly in this ground (1), (2) is a groove at a predetermined interval (1a) A pair of molds installed above, (3) are collateral muscles, which support the molds (2) at regular intervals. (4) and (5) are a main muscle and a vice muscle, which are supported by the collateral muscle (3) and are installed at predetermined positions, respectively.
(6) is an anchor muscle embedded in the groove (1a) at a predetermined interval.

As shown in FIG. 15, when each material can be assembled, from the top to between the formwork (2), concrete or mortar (hereinafter referred to as concrete as a concept including mortar in this specification) Is blow-filled with compressed air and cured. The mold (2) may be removed after hardening of concrete or the like, but may be so-called buried.

FIG. 16 is a plan view showing the appearance of a concrete structure formed on the ground surface after the reinforcement work is completed, and FIG. 17 is a sectional view taken along line XVII-XVII in FIG.

[Problems to be Solved by the Invention]

Conventionally, since the ground reinforcement is performed in the above manner, there is a problem in the mechanical strength of the finished concrete structure. That is, since the spraying of concrete is performed from above the formwork (2), it is difficult to fill this sprayed concrete on the lower surface side of each rebar (3) (4) (5), a hollow portion occurs, etc. It has a drawback that the adhesion between the reinforcing bar and the concrete becomes insufficient and the final compressive strength cannot be expected to have a sufficient design strength as compared with the case where the concrete is completely filled. Therefore, it is necessary to set the design strength low accordingly. Further, during the spraying work, there is a loss of concrete flowing out of the formwork, and usually, a shaping finishing work by a trowel or the like is required. Therefore, there is a problem that both the material and the manufacturing cost are high.

Of course, if the so-called cast-in-place concrete construction method using ready-mixed concrete is adopted as in the case of normal concrete construction, the above problem of strength can be solved. However, if an attempt is made to install a formwork that has a high airtightness according to its shape on a sloping ground, the equipment will become large and the workability will be poor, and the construction site will be greatly limited.

The present invention has been made to solve the above-mentioned conventional problems. It is possible to obtain a high design strength by using cheap ready-mixed concrete, standardize necessary equipment, and reuse a part of it. The purpose is to provide an economical and highly reliable ground reinforcement method.

[Means and Actions for Solving the Problems]

The ground reinforcement method according to the present invention, first, the following steps,
That is, a step of forming a flat base surface on the surface of the ground to be reinforced, a step of fixing the fixing plate having an opening to the ground surface to the base surface by an anchor bar, and the fixing plate A step of arranging the main bar at a predetermined position by supporting it through a streak frame, a step of forming a predetermined closed space by attaching a mold to the fixing plate so as to cover the main bar, and It comprises a step of injecting and filling concrete and hardening, and a step of removing the mold from the fixing plate after hardening. As a result, the ready-mixed concrete comes into close contact with the main bars to form an integral structure, and reaches the ground surface from the opening provided in the fixing plate, and firmly adheres to the ground. The formwork can be removed and reused, and the hardened concrete structure is finished as it is without the need for shaping work.

And, when the plural molds are connected to each other, the end of one of the molds adjacent to each other is fitted into the end of the other mold through a predetermined gap. The above gap is filled with a packing.

In this case, due to the surface shape of the ground, even if the central axes of the two adjacent formwork incline vertically or horizontally, the packing expands and contracts to always fill the gap. It does not leak from the connecting part of the frame.

According to a second aspect of the present invention, the ends of the two molds adjacent to each other are arranged so as to face each other, and a groove having a predetermined depth that opens in the facing direction is formed along the peripheral edges of the ends of the two molds. However, flexible plates whose axial ends are inserted into the grooves of the two molds are provided so as to connect the two molds.

Also in this case, similarly to the above, even if the central axes of both molds are slightly inclined, the flexible plate is deformed to maintain the hermeticity, and leak of fresh concrete from the connecting portion is prevented.

Further, according to a third aspect of the present invention, an opening and a locking portion are formed on the upper surface of the mold, a water stop plate slidably mounted on the locking portion to open and close the opening, and the locking portion. And a pouring port for pouring fresh concrete, which is detachably attached to.

In this case, since the fresh concrete is poured and filled through the injection port communicating with the opening on the upper surface of the mold, the filling work can be performed quickly. When the filling is completed, the water blocking plate slides to close the opening. The inlet can be removed and used for other forms.

〔Example〕

The ground reinforcement method in one embodiment of the present invention will be described below with reference to the drawings.

First, a flat base surface is formed on the surface of the ground to be reinforced. This is a pretreatment for fixing the fixing plate, which will be described in detail below, to the ground in a predetermined posture. FIG. 1 is a plan view showing the fixing plate (7) fixed to the base surface, and FIG.
It is sectional drawing of the I-II line. In the figure, (1) is the ground, (1b)
Is a base surface formed on the surface of the ground (1), and is finished in a flat shape to keep the fixing plate (7) in a fixed position and posture. Foundation surface (1
b) is formed by spraying concrete or mortar. Since it is not necessary to finish the entire surface of the ground (1) but only the part where the fixing plate (7) is attached, it is sufficient to finish it in a flat shape, for example, using a template that matches the shape of the fixing plate (7). You may want to raise it. Reference numeral (71) is a straight-line fixing plate, which is manufactured using lightweight steel that is mass-marketed. As shown in detail in the perspective view of FIG. 3, angled steel materials (71a) are arranged in parallel on both sides, and plate-shaped steel materials (71b) are arranged at a predetermined interval between both steel materials (71a). Are joined by welding. There is an opening (71c) between the steel materials (71b). (72)
Is a corner fixing plate, and each end is connected to the linear fixing plate (71) by bolting (portion indicated by A in FIG. 1) to be integrated. A steel material (72a) is integrally joined by welding to the vicinity of the peripheral edge so as to be connected to the vertical side of the angled steel material (71a) of the straight part fixing plate (71). (72b) is a steel material for attaching a later-described streak frame or the like, and also serves as reinforcement of the fixing plate (72). (72c)
Is an opening provided in the corner fixing plate (72). (8)
Is a round hole for the main anchor bar (8a) (not shown) provided in the center of the corner fixing plate (72), and (9) is both fixing plates (71) (72)
These are round holes for auxiliary anchor muscles (9a) provided at appropriate intervals on the side of the. And each fixing plate (71) (72) is a ground (1)
The main anchor muscles (8a) and the auxiliary anchor muscles (9a) are firmly fixed to the base surface (1b) at predetermined positions.

Next, a steel main bar, which is a strength member of the concrete structure, and a frame for fixing and supporting the main bar are attached. FIG. 4 is a cross-sectional view taken at the same position as in FIG. 2 in order to explain this step and the step of attaching the next mold together. In the figure, reference numeral (10) is a collateral bar, which is supported and fixed to the straight-line fixing plate (71) by using a round hole provided in the steel material (71b). The corner fixing plate (72) is made of steel (72
It is fixed using the round hole provided in b). (11) is the collateral muscle supported and fixed via the collateral muscle (10).
The frame (12) is formed by 1). And both fixing plates (71) (7
By supporting from 2) via the frame (12), the main bar (13)
Supported and fixed in place.

When the streak frame (12) is attached at a predetermined position, next, as shown in FIG. 4, a mold frame (14) having a U-shaped cross section is attached to the fixing plate (71), and an enclosed space (15) is formed inside. ) Is formed. The formwork (14) is attached to the straight part fixing plate (71). As shown in the perspective view of FIG. 5, a mounting piece (14a) is formed at the longitudinal side end, and the auxiliary anchor bar (9a) is formed. ) Through hole (14b)
Is provided. In addition, flange pieces (14
c) is formed, and is configured to come into contact with a flange piece that is also formed on the form (16) attached to the adjacent corner fixing plate (72). In the above embodiment, the attachment of the formwork (14) (16) uses the auxiliary anchor bar (9a) embedded in the foundation surface (1b) to drive a hook into the hook formed at the tip of the form. The fixing plate (71) (72) is fixed integrally with the fixing plate (71), but for example, the steel plate (71a) of the fixing plate (71) is provided with a screw stud facing upward, and the fixing piece of the mold (14) is attached to this. (14
A method of inserting the round hole provided in a) and tightening and fixing with a nut may be adopted.

FIG. 6 is a perspective view showing a state in which all the mold forms (14) and (16) have been attached. Adjacent molds are connected to each other by abutting flange pieces formed at the ends of the two and holding them by clamps (17) from the outer circumference. In addition, a packing is appropriately inserted between both flange pieces to improve the degree of sealing.

When the installation of the molds (14) and (16) is completed over the construction range, the end part is appropriately closed using steel material, the injection hole is provided in the formwork located at the upper end of the slope, and the fresh concrete is started from here. Is injected and filled by a pump car. Although not shown in FIG. 6, if an air vent is provided at an appropriate place on the molds (14) and (16) and the air vent is appropriately opened and closed at the injection stage of the fresh concrete, Filling speed is faster,
Moreover, the filling degree is also improved. Further, if a transparent window is provided in a part of the mold or the mold itself is made of a transparent material, the progress of filling can be visually checked.

In addition, if a vibrator is used in combination, the filling of the end portion becomes particularly easy.

FIGS. 7 to 9 show a structure in which an injection port is provided in the mold (16) itself so that the filling work of the ready-mixed concrete can be performed more quickly. FIG. 7 is a plan view thereof, and FIGS. 8 and 9 are sectional views taken along lines VIII-VIII and IX-IX of FIG. 7, respectively. In the figure, (18) is a top plate which is the upper surface of the formwork (16), (19) is an opening formed in the top plate (18), and (20) is a predetermined distance from the top plate (18). An engaging portion formed by connecting substantially parallel U-shaped plate members with their three side edges connected to the top plate (18), and (21) is a screw part (21) on the outer periphery of the metal pipe.
a) and a collar (21b) formed at the lower end, and the collar (21b) is inserted into the locking portion (20) from the lower position shown in FIG. As shown in FIG. 8, the water stop plate (22) is inserted and fixed below the inlet (21).

Fix the water stop plate (22) to the position shown in FIG. 8 with a fixture (not shown), screw the end of the hose from the pump car to the screw part (21a) of the inlet (21), and mix the ready-mixed concrete. The closed space (15) formed by the mold (16) is injected and filled from the opening (19).

When the filling is completed, in FIG. 8, slide the water stop plate (22) to the left to close the opening (19), and then connect the hose to the inlet (2).
Remove from 1) and move the work to the next formwork. It is also possible to remove the injection port (21) and divert it to another part in the mold after curing.

Needless to say, the opening (19) and the inlet (21) can also be used as the air vent plug described above.

When the fresh concrete is completely filled in the closed space (15),
Since the fixing plates (71) and (72) are provided with openings (71c) and (72c), the raw concrete naturally reaches the surface of the natural ground (1) through this opening, and the hardening causes it to become the natural ground (1). It adheres with high adhesive strength. Therefore, this effect is added to the fixing force by the anchor muscles (9a) (9b), and the fixing plates (71) (72) and the main muscles (1
3) The fixing force of the streak frame (12) to the natural ground (1) is further strengthened.

Also, instead of spraying as in the past, fresh concrete is filled in the sealed space (15) in a pressurized state, so that it is completely in close contact with the main bar (13) and integrally joined to form a concrete structure. Demonstrate the original high mechanical properties.

When the ready-mixed concrete is sufficiently filled and a predetermined hardening time has passed, all the formwork (14) and (16) are removed, and the reinforcing work is completed. Concrete is filled in the molds (14) and (16) without voids, so if the molds (14) and (16) are removed, the surface of the structure is finished as it is, and the subsequent shaping and finishing work is performed. do not need. If you use colored concrete such as green,
It has a better appearance and is especially useful in tourist areas.

In the case of the conventional construction method, there was a phenomenon that concrete collapsed in 1-2 years after construction due to freezing of the infiltrated water in the winter, but in this construction method, there was no such development and it was stable. A reinforced surface is obtained. Therefore, for example, if a long lock bolt or the like is used as the anchor bar, it is possible to achieve reliable prevention of topsoil collapse over many years.

As described above, according to this construction method, the molds (14) and (16) can be reused, so that even if the material cost and the processing cost are slightly increased, the overall economical efficiency is not deteriorated. Therefore, the formwork (14) (16)
Is not necessarily made of steel, but may be cast by FRP or synthetic resin by unifying the dimensions and shapes. In this case, if the material itself is transparent or translucent, There is also an advantage that the filling status of the ready-mixed concrete can be immediately grasped.

The fixing plate (7) is a so-called buried item and becomes a consumable item for each construction. However, in this construction method, the size and shape can be unified, which is the same as the formwork (14) (16) described above. It is similar to the case. Therefore, cost reduction by mass production is sufficiently possible.

Regarding the work content when implementing this method, the first step, the formation process of the foundation surface, must be an individual work in accordance with the surface shape of each ground to be constructed. Since all the work contents of the subsequent processes can be unified and standardized, it is easy to save labor and shorten the construction period.

By the way, depending on the surface shape of the ground to be reinforced, it may be difficult to make all of the foundation surfaces to be formed in the first stage flat. That is, FIG. 10 shows the situation in this case, the figure (A) is a view of the ground (1) as seen from the side, and the foundation surface (1b) of the adjacent formwork (14) (16). Each connecting portion has a constant inclination θ. Therefore, in such a portion, as shown in FIGS. 4 and 5 and further in FIG. 6, the flange pieces (14c) formed at the longitudinal ends of the mold (14) are fitted. The connection structure of contacting and holding by the clamp (17) does not provide a sufficient sealed structure, and fresh concrete leaks out from this part, which cannot be put to practical use.

In addition, Fig. 10 (B) is a plan view of the natural ground (1) seen from above, and when the central axes of the adjacent formworks (14) and (16) are tilted in the left-right direction by an angle θ, depending on the terrain situation. Indicates. Again, the same figure
Similar to the case of (A), there is a problem in the connection structure of the flange pieces (14c) and (16c).

In this case, the types of formwork (14) and the like may be increased according to the shape of the ground (1), but especially when using expensive materials such as FRP for this formwork (14) and the like. However, the economic efficiency will be greatly impaired.

However, the foundation surface (1b) should always be finished in a flat shape, but depending on the shape of the ground (1), this foundation surface (1b)
There are many cases where the construction scale is huge and uneconomical.

The embodiment described below is an improvement of the connecting mechanism when a plurality of molds (14) and the like are connected and arranged on the ground (1) in the step of the reinforcing work as described above.

FIG. 11 is a side view showing a partial cross-section of one embodiment of this connecting mechanism, and FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. In the figure, (14) is a straight part form, (14a) is its mounting piece, (1
6) is the corner form, and (16a) is its mounting piece. And, (71a) is an angle-shaped steel piece of the straight part fixing plate (71), (72a)
Is a steel material for the corner fixing plate (72) and is fixed to the base surface (1b) formed on the ground (1) by using not-shown auxiliary anchor streaks or the like. Note that the streak frame (12) and the like are omitted in these figures.

A stepped portion (16b) is formed at an end of the corner portion form (16), and has a diameter increased by a predetermined length. On the other hand, the straight part formwork (14) has a constant U-shaped cross section, does not have the flange piece (14a) as shown in FIG. 5, and its end portion has a corner part formwork (1).
It is structured to fit in the stepped portion (16b) of 6).

Then, a predetermined gap (23) is secured between the inner surface of the stepped portion (16b) and the outer surface of the form (14), and the gap (23)
Insert the packing (24) such as silicone rubber into.

The work order is as follows: first, attach the straight part formwork (14) to the angled steel piece (71a), then place the packing (24) at the end of this formwork (14), and then Steel (72a) so that the step (16b) of the frame (16) overlaps the end of the form (14).
Attach and fix to. In addition, in order to position the packing (24), for example, at the position on the outer peripheral surface of the mold (14),
You may make it form the groove which fits a part of (24).

Because of the above configuration, in FIG. 11 both formwork (14) (16)
The center axes of the two are shown to match, but as shown in FIG. 10, even when these center axes are slightly tilted vertically or horizontally, the tilted portion is absorbed within the range of the gap (23). be able to. Since this gap (23) is always filled and closed by the packing (24), even when pouring fresh concrete into the formwork (14) (16), the fresh concrete leaks out from this connecting part. There is nothing to do.

As a result of trial production by the inventors, it was found that the inclination of up to about 30 ° can be absorbed by appropriately selecting the size and width of the gap (23) and the type and shape of the packing (24). As a result, it is possible to significantly reduce the types of formwork required for concrete construction.

FIG. 13 is a side view partially showing a cross section of another embodiment of the frame connecting mechanism, and FIG. 14 is a cross sectional view taken along line XIV-XIV in FIG. Here, both molds (14) and (16) have thick portions (14d) and (16d) formed at their ends, and both thick portions (14d) ( Grooves (14e) (16e) having a predetermined depth are provided along the peripheral edge in the center of the thickness direction of 16d).

Then, the both sides in the width direction of the flexible plate (25) made of silicon rubber or the like are fitted into both the grooves (14e) and (16e), and the both molds (14) and (16) are arranged to face each other. , And the angle-shaped steel piece (71a) and the steel material (72a), respectively.

That is, here, the deformable flexible plate (25) covers the part of the longitudinal gap (26) generated between the two molds (14) and (16) to seal the closed space (15). That is the reason for ensuring the sex.

Therefore, by appropriately selecting the size of the gap (26) and the material and shape of the flexible plate (25), it is possible to absorb the inclination between the connected molds in a wider range.

〔The invention's effect〕

As described above, in the present invention, first, a fixing plate having an opening is fixed to a base surface formed on the surface of the ground by an anchor bar, and the fixing frame and the main bar and the formwork covering the fixing frame are fixed to the fixing plate. To form a closed space, and to inject and fill fresh concrete into the closed space and cure it, and then remove the formwork, the concrete and the main bar and the frame are completely in close contact with each other and become a unitary structure. In addition to obtaining the original high mechanical strength of the material, the strength of adhesion between the finished concrete structure and the ground is also strengthened. Significantly improved. If the strength is the same as the conventional one, the material can be saved significantly. In addition, early destruction of concrete due to freezing is prevented, and the life of the reinforcing surface is increased. Furthermore, unlike the conventional so-called cast-in-place concrete construction method, all the equipment can be unified in size and shape, so both equipment costs and on-site work costs can be greatly reduced, and the formwork itself can be reused. Further, the cost can be further reduced.

Then, one end of the formwork to be connected is fitted into the other end, and the gap is filled with packing.
Even if the central axes of the two adjacent formwork are slightly inclined vertically or horizontally, the packing expands and contracts to always fill the gap, so that leakage of fresh concrete from this connecting portion is prevented. Therefore, it is possible to significantly reduce the types of formwork required for concrete construction due to the shape of the ground, etc., and the economical efficiency and practicability of the present reinforcement method are greatly improved.

Further, since the molds to be connected are arranged so as to face each other and the flexible plate is inserted across the groove formed along the peripheral edge of the end, the flexible plate can be appropriately deformed. Due to
It is possible to absorb the inclination between the molds in a wider range,
It is possible to further reduce the required types of formwork.

Further, since the opening and the locking portion are formed on the upper surface of the form, and further the predetermined water blocking plate and the injection port are provided, the filling work of the fresh concrete can be performed quickly.

[Brief description of drawings]

FIG. 1 is a plan view for explaining a fixing plate installation step in one embodiment of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 shows a structure of a straight-line fixing plate. FIG. 4 is a perspective view, FIG. 4 is a cross-sectional view for explaining the attaching process of the reinforcement frame, the main reinforcement and the form, FIG. 5 is a perspective view showing the structure of the form of the straight part, and FIG. FIG. 7 is a perspective view showing a state, FIG. 7 is a plan view showing an embodiment in which an injection port is provided in the mold itself,
8 and 9 are cross-sectional views taken along lines VIII-VIII and IX-IX of FIG. 7, respectively, and FIG. 10 is a view showing a situation where the central axes of the molds to be connected are inclined, and FIG. FIG. 12 is a side view showing the connecting mechanism of a mold according to another embodiment in a partial cross section, FIG. 12 is a sectional view taken along the line XII-XII in FIG. 11, and FIG. 13 is a mold according to still another embodiment. A side view showing the connecting mechanism in a partial section,
Fig. 14 is a cross-sectional view taken along the line XIV-XIV in Fig. 13, Fig. 15 is a cross-sectional view illustrating a conventional so-called shotcrete construction method, and Fig. 16 is an external view of a concrete structure formed as ground reinforcement. The plan view shown in FIG. 17 is XVII-XV in FIG.
It is a sectional view taken along line II. In the figure, (1) is a ground, (1b) is a base surface, (7) (71) (72) is a fixing plate, (71c) (72c) are openings provided in the fixing plate, (8) (9) )
Is a round hole for anchor reinforcement, (9a) is an auxiliary anchor reinforcement, (12) is a frame, (13) is a main reinforcement, (14) and (16) are formwork, (15) is a closed space, (1
8) is a top plate which is the upper surface of the mold, (19) is an opening, (20) is a locking part, (21) is an inlet, (22) is a water stop plate, (23) and (26) are gaps, (2
4) is a packing, and (25) is a flexible plate. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (3)

[Claims] 1. A step of forming a flat base surface on the surface of the ground to be reinforced, a step of fixing a fixing plate having an opening to the ground surface to the base surface by an anchor bar, Arranging the main bar at a predetermined position by supporting it from the fixing plate via a streak frame; forming a predetermined closed space by attaching a mold to the fixing plate so as to cover the main bar; A ground reinforcement method comprising the steps of injecting and filling a space with fresh concrete and hardening it, and removing the formwork from the fixing plate after hardening, which is a closed space in which a plurality of the formwork are connected to communicate with each other. In the case of forming, the ground reinforcement method in which the ends of one of the molds adjacent to each other are fitted into the ends of the other mold via a predetermined gap, and the gap is filled with a packing. 2. A step of forming a flat base surface on the surface of the ground to be reinforced, a step of fixing a fixing plate having an opening to the ground surface to the base surface by an anchor bar, Arranging the main bar at a predetermined position by supporting it from the fixing plate via a streak frame; forming a predetermined closed space by attaching a mold to the fixing plate so as to cover the main bar; A ground reinforcement method comprising the steps of injecting and filling a space with fresh concrete and hardening it, and removing the formwork from the fixing plate after hardening, which is a closed space in which a plurality of the formwork are connected to communicate with each other. In the case of forming, the end portions of both molds adjacent to each other are arranged so as to face each other, and a groove of a predetermined depth is formed along the peripheral edges of the end portions of the both molds, the groove having a predetermined depth, Both ends of the direction are A natural ground reinforcement method in which a flexible plate to be inserted into the groove is provided so that the two molds are connected to each other. 3. A step of forming a flat base surface on the surface of the ground to be reinforced, a step of fixing a fixing plate provided with an opening to the ground surface to the base surface by an anchor bar, Arranging the main bar at a predetermined position by supporting it from the fixing plate via a streak frame; forming a predetermined closed space by attaching a mold to the fixing plate so as to cover the main bar; A ground reinforcement method comprising the steps of injecting and filling fresh concrete into a space and hardening it, and removing the formwork from the fixing plate after hardening, wherein an opening and a locking part are formed on the upper surface of the formwork. Then, the ground reinforcement provided with a water stop portion slidably attached to the locking portion to open and close the opening, and an injection port detachably attached to the locking portion for pouring fresh concrete. Construction method.