JP3558280B2 - Ground reinforcement method using rock bolts - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a ground reinforcement method such as a rock bolt method in which a reinforcing material such as a rock bolt is inserted into a drilling hole formed in the ground and a solidifying material is injected to fix the reinforcing material to the ground.
[0002]
[Prior art]
For the ground reinforcement method using rock bolts, the construction form is selected depending on the self-sustained stability of the ground. That is, in the ground where the drilling hole can be self-supporting, the drilling rod itself forms a drilling hole in the ground without drilling the casing, then inserts the rock bolt reinforcement into the formed drilling hole and solidifies. An injection pipe of the material is inserted to the vicinity of the tip of the rock bolt reinforcement, and the solidified material is injected into the borehole through the injection pipe.
[0003]
On the other hand, in the ground where the excavation hole is difficult to stand on its own, first, the ground is excavated using a double pipe rod having a casing outer pipe and an inner pipe, and a drill bit at the tip thereof. After the excavation is completed, only the inner pipe is pulled out of the ground, and a rock bolt reinforcing material is inserted into the drawn hole. Next, the injection pipe is inserted to the vicinity of the distal end of the casing outer pipe. After inserting the injection pipe, the casing outer pipe is pulled out from the ground while a solidified material such as cement milk is injected into the drill hole through the injection pipe.
[0004]
The reason why such a form is adopted for the ground in which the excavation hole is difficult to stand by itself is to prevent the collapse of the hole wall at the time of excavation and injection of the solidified material by the casing outer tube.
[0005]
[Problems to be solved by the invention]
However, in the former mode, even if the drilling hole is self-supporting at the time of drilling, the hole wall must not collapse by the stage of injecting the liquid solidification material, so that it can be left for a long time from the time of excavation to the time of injection. In addition, after excavation and pouring at a certain point, the construction of each individual point that moves to the next point is inevitable.
[0006]
In the latter case, even if a casing outer tube is used, in order to integrate the ground and the reinforcing material, the casing outer tube must be pulled out before the solidified material is solidified. Simultaneously or after withdrawal, the hole wall of the borehole may collapse, leading to a situation where injection cannot be performed reliably.
[0007]
As described above, none of the conventional examples described above takes measures for preventing collapse of the hole wall.
[0008]
If the hole wall collapses before and after the solidification material is injected, a part of the excavation hole is filled with earth and sand, and a portion where the reinforcing material and the earth and sand are in direct contact is formed. When the reinforcing material comes into direct contact with the earth and sand, the portion is no longer covered with the solidifying material, the fixing power of the reinforcing material to the ground is weakened, and a desired reinforcing effect cannot be obtained. Further, when the reinforcing material comes into direct contact with earth and sand or groundwater, the portion is easily corroded, and its durability is significantly reduced.
[0009]
Therefore, a first object of the present invention is to reliably prevent collapse of a hole wall of an excavation hole, and a second object is to perform an operation of excavating a ground and an operation of injecting a solidified material in parallel. Is to do so.
[0010]
[Means for Solving the Problems]
The inventions described in the respective claims that have solved the above-mentioned problems and the functions and effects thereof are as follows.
<Invention according to claim 1>
In the ground reinforcement method by the rock bolt which drives a plurality of rock bolt reinforcements on the ground to be reinforced,
Forming a drilling hole in the ground with a drilling pipe, inserting a rock bolt reinforcing material in the drilling pipe, and a tubular penetrating material that covers and covers the drilling hole and allows the solidified material to penetrate and penetrate,
The solidification material is injected into the excavation hole, penetrates into the voids of the infiltration material, the reinforcing material is fixed to the ground through the outer peripheral surface thereof, and the solidification is performed before the injection of the excavation pipe is started or the injection is performed. Before the hardening of the material,
A ground reinforcement method characterized in that the excavation pipe used for the excavation hole is used for excavation work for another excavation hole at the same time as the injection work for the excavation hole.
[0011]
(Operation and Effect of the Invention of Claim 1)
Since the solidifying material covers the reinforcing material with a penetrating material that can penetrate and permeate, and allows the solidifying material to penetrate into the voids of the penetrating material, the solidifying material can reliably exist around the reinforcing material.
[0012]
Furthermore, since the penetrating material covers the periphery of the reinforcing material, the hole wall is prevented from collapsing after the reinforcing material is inserted, or at least even if the collapsing occurs, the reinforcing material and the earth and sand are in direct contact. Disappears. Therefore, the excavation hole can be left in a state where the reinforcing material is inserted, and the reinforcing material inserting operation step and the solidifying material injection step can be performed separately, not continuously. become.
[0013]
Further, since the hole wall is protected by the drilling pipe, the hole wall does not collapse before the reinforcing material and the penetrating material are inserted.
[0014]
In particular, for a self-sustaining stable ground, a drilling hole is formed by a drilling rod, and a reinforcing material and a tubular infiltration material through which a solidified material covering the reinforcing material can penetrate is inserted into the drilling hole from which the drilling rod is pulled out. Thus, the penetrating material prevents the collapse of the pore wall, and the injection operation can be performed reliably.
[0015]
In addition, by using the casing outer pipe, construction is possible even on the ground where it is difficult to self-support the excavation hole, and at the stage where the casing outer pipe is pulled out, the penetrating material prevents collapse of the hole wall and injects Work can be performed reliably.
[0016]
<Invention according to claim 2>
A hollow channel is formed in the reinforcing material, the solidified material is supplied through the hollow channel and discharged to the outside, the solidified material is injected into a drilling hole, and the solidified material is permeated into the voids of the penetrating material, The ground reinforcement method according to claim 1, wherein the ground is fixed to the ground via the outer peripheral surface.
[0017]
(Operation and Effect of the Invention of Claim 2)
By supplying the solidified material through the hollow passage of the reinforcing material and discharging the solidified material to the outside and injecting the solidified material into the excavation hole, the injection can be reliably performed, and the discharge port of the hollow passage is connected to the tip of the reinforcing material. By doing so, the injection can be reliably performed up to the bottom of the excavation hole.
[0018]
<Invention of Claim 3>
The infiltration material may have some flexibility, is in a form that itself exhibits shape retention and prevents collapse of the pore walls, and with respect to penetration and permeation of the solidification material, The ground reinforcement method according to claim 1 or 2, wherein the material and the shape are materials and shapes that can penetrate and penetrate inside and outside surfaces of the material.
[0019]
(Operation and Effect of the Invention of Claim 3)
According to such a penetrating material, collapse of the pore wall can be reliably prevented.
[0020]
<Invention of Claim 4>
The ground reinforcing method according to any one of claims 1 to 3, wherein the reinforcing material and the tubular penetrating material covering the reinforcing material are simultaneously inserted into the excavation hole.
[0021]
(Operation and effect of the invention according to claim 4)
By simultaneously inserting the reinforcing material and the tubular penetrating material covering the same into the drilling hole, the shape of the tubular penetrating material is maintained, and breakage of the tubular penetrating material can be prevented.
[0022]
<Invention according to claim 5>
The reinforcing material and the cylindrical penetrating material covering the reinforcing material are simultaneously inserted into the excavation hole in a state in which the tip of the cylindrical penetrating material is integrated with the tapered shoe material having a higher strength than the penetrating material. The ground reinforcement method according to any one of Items 1 to 4.
[0023]
(Operation and effect of the invention according to claim 5)
The same effect as that of the fourth aspect is obtained, and in addition to the effect, the tip of the tubular permeable material is integrated with the shoe material having higher strength than the permeable material, so that the tip of the permeable material is protected. In addition, the tapering of the shoe material facilitates insertion.
[0024]
(Other effects)
After inserting the reinforcing material and the penetrating material into multiple excavation holes in the ground, by sequentially or simultaneously injecting into each excavation hole, the excavation process of the excavation hole, the penetration material and the rock bolt reinforcement material Since the insertion step and the solidification material injection step are separable, it is possible to effectively use the excavator and the excavation equipment, and it is possible to effectively arrange the workers so that the solidification waiting time does not occur. is there.
[0025]
In addition, every time a drilling hole is formed, a reinforcing material and a cylindrical penetrating material are inserted into the drilling hole, so that even in the case of a ground where self-sustainability is difficult, the reinforcing material and the cylindrical material can be inserted into a plurality of drilling holes. The solidified material can be sequentially or simultaneously injected into each of the excavation holes with the shape-penetrating material inserted.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
In the ground reinforcement method of the present invention, as shown in FIG. 1, a tubular penetrating material 2 that allows a solidified material covering the same to penetrate and permeate a rock bolt reinforcing material 1 is basically used as shown in FIG. 1. As long as the permeation material 2 prevents the collapse of the pore wall, the permeation material 2 itself exhibits shape retention properties (may have some flexibility). The material and shape are not limited as long as the material and shape can penetrate and penetrate into the inside and the inside and outside surfaces of the penetrating material 2. Examples of suitable shapes other than the shape shown in FIG. 1 are shown in FIGS. In any shape, the thickness T of the penetrating material is preferably 10 mm or more so that the solidified material sufficiently penetrates into the penetrating material. Suitable materials include a porous material, a fibrous material, a resin material, and a net-like material having a void that is continuous or communicated with the inner and outer surfaces.
[0027]
On the other hand, as shown in FIG. 4, the lock bolt reinforcing member 1 has a hollow passage 1h formed therein, and through the hollow passage 1h, the inside of the excavation hole 20 (see FIG. 8 et seq.) And the inside of the penetrating material 2. , And the solidified material M can be injected into the outer peripheral surface of the lock bolt reinforcing material 1. As shown in FIG. 5, it is also possible to form an injection path 2h of the solidifying material in the infiltration material 2 and to inject the solidification material M through the injection path 2h. If the injection path is not used, the reinforcing material 1 can be made solid.
[0028]
On the other hand, to facilitate insertion of the penetrating material 2 into the hole, a shoe member 3 made of a metal or a hard synthetic resin or the like having a higher strength than the tapered penetrating material 2 can be attached to the tip of the penetrating material 2. Details of the shoe member 3 are shown in FIGS. FIG. 6 is a front view of the shoe member, and FIG. 7 is a view seen from the direction of VII in FIG. The split member attachment portion 3c formed to fit tightly on the inner surface of the distal end of the tubular penetrating material 2 and the distal end is inserted into a portion surrounded by the split member attachment portion 3c. A guide path 3g is formed to guide the solidified material M that has passed through the hollow path 1h of the rock bolt reinforcing material 1 to the penetrating material 2 side.
[0029]
<Reinforcing example 1: Example for collapsed ground>
Next, a first example of placing a reinforcing material in the ground reinforcement method of the present invention will be described below.
First, as shown in FIG. 8, a double pipe rod 10 having a casing outer pipe 10c and an inner pipe 10i having a drill bit 10b attached to the tip thereof is rotated and propelled to excavate the ground G to excavate the excavation hole 20. To form The drill bit 10b may be a discard bit that is left inside the drill hole 20 after forming the drill hole 20.
[0030]
Next, when the double pipe rod 10 is inserted into the ground G, as shown in FIG. 9, only the inner pipe 10i of the double pipe rod 10 is pulled out. When the inner tube 10i is pulled out, a drawing hole 10h is formed in the casing outer tube 10c. Then, as shown in FIG. 10, the solidified material to be injected later can penetrate into the drawing hole 10h. A rock bolt reinforcing material 1 covered with a penetrating material 2 made of a material is inserted.
[0031]
In the present invention, it is not necessary to insert the lock bolt reinforcing material 1 covered with the penetrating material 2 as in the above-described example. On the other hand, it is sufficient if the penetrating material 2 is in a state of being covered. Therefore, the cylindrical penetrating material 2 may be inserted first, and then the lock bolt reinforcing material 1 may be inserted into the inner hole, or vice versa.
[0032]
After the rock bolt reinforcing member 1 covered with the penetrating material 2 is inserted into the extraction hole 10h, the casing outer tube 10c is extracted from the excavation hole 20 as shown in FIG. Next, as shown in FIG. 12, the operation of injecting the solidified material M is started. The solidified material M is injected into the excavation hole 20 through the injection path 2h in the infiltration material 2 or the hollow path 1h formed in the lock bolt reinforcing material 1 as shown in the figure.
[0033]
The solidified material M is sequentially penetrated from the lower part to the upper part of the infiltration material 2 while passing through the gap between the guide path 3g and the split mold attachment part 3c, and is also filled into the excavation hole 20, and at the same time, It also extends to the outer peripheral surface and covers the outer peripheral surface. When the solidified material M is solidified, as shown in FIG. 13, the solidified material M penetrates into the void portion of the infiltration material 2, so that the rock bolt reinforcing material 1 and the ground G are integrated, and the rock bolt reinforcing material 1 It is established against.
[0034]
In this manner, when the driving of the lock bolt reinforcing member 1 is completed, the head 1t of the lock bolt reinforcing member is subjected to a fixing process to a legal frame, a structure, or the like according to the purpose, based on the related art.
[0035]
<Reinforcing material placing example 2: example for self-supporting ground>
7 shows a second example of placing a rock bolt reinforcing material in the ground reinforcement method of the present invention.
First, as shown in FIG. 14, the drilling rod 11 is inserted into the ground G while excavating the ground G using a single pipe drilling rod 11 having a drilling bit 11b attached to the tip. The drill bit 11b can be a discard bit. When the excavation is completed, as shown in FIG. 15, the drilling rod 11 is pulled out from the ground G, and an excavation hole 20 is formed as shown in FIG. After the excavation hole 20 is formed in this way, as shown in FIG. 17, the rock bolt reinforcing material 1 previously covered with the penetrating material 2 through which the solidified material M can penetrate is inserted into the excavation hole 20. In the illustrated example, the lock bolt reinforcing material 1 is inserted in advance into the inner hole of the cylindrical penetrating material 2. At this time, the tubular penetrating material 2 may be inserted first, and then the lock bolt reinforcing material 1 may be inserted into the inner hole.
[0036]
When the rock bolt reinforcing material 1 covered with the penetrating material 2 is inserted into the excavation hole 20, through the hollow passage 1 h in the rock bolt reinforcing material 1 or the injection passage 2 h formed in the penetrating material 2, as in the case of the casting example 1 described above. As shown in FIG. 18, the solidified material M is injected into the excavation hole 20. When the operation of injecting the solidified material M is completed, the solidification is waited for. When the solidified material M is solidified, as shown in FIG. 19, the solidified material M is solidified including the void portion of the infiltration material 2, the rock bolt reinforcing material 1 and the ground G are integrated, and the rock bolt reinforcing material 1 G is fixed.
[0037]
In this manner, when the driving of the lock bolt reinforcing member 1 is completed, the head 1t of the lock bolt reinforcing member is subjected to a fixing process to a legal frame, a structure, or the like according to the purpose, based on the related art.
[0038]
<First Construction Example of the Present Invention>
A construction example of the ground reinforcement method of the present invention will be described.
Generally, a plurality of lock bolt reinforcing members 1 are cast on the ground to be reinforced. Then, it is possible to shorten construction time by specifically performing construction as described below.
[0039]
First, according to the casting example 1 or the casting example 2, when the insertion of the rock bolt reinforcing material 1 covered with the penetrating material 2 into the excavation hole 20 is completed at a certain point, the solidification is immediately performed on the excavation hole 20. Rather than performing the operation of injecting the material M, the process up to the step of inserting the lock bolt reinforcing material 1 is similarly performed at another point. This operation is repeated, and after the rock bolt reinforcing material 1 is inserted into all the desired points on the ground, the operation of injecting the solidified material into those excavation holes 20 is started. The solidification material may be injected by sequentially injecting the solidification material M into the excavation hole into which the lock bolt reinforcing material is inserted, or the solidified material M may be pumped through the plurality of excavation holes 20, 20,. , And may be simultaneously injected into the excavation holes 20. In the case where only the penetrating material 2 is inserted into the excavation hole 20 first, the rock bolt reinforcing material 1 is inserted into the excavation hole 20 before the solidification material M is injected.
[0040]
As described above, since the excavation step of the excavation hole, the insertion step of the penetrating material 2 and the lock bolt reinforcing material 1, and the injection step of the solidified material can be separated, the excavator and the excavation equipment can be effectively used. , As well as the effective placement of workers so that no solidification waiting time occurs.
[0041]
<Second embodiment of the present invention>
The ground reinforcement method of the present invention can also be performed as follows.
Conventionally, when forming a borehole using a casing outer tube, the casing outer tube cannot be pulled out until a solidifying material is injected. However, in the ground reinforcement method of the present invention, the casing outer tube 10c can be pulled out when the lock bolt reinforcement 1 is inserted, as described in the casting example 2. Therefore, the second construction example of the present invention is that, after inserting the rock bolt reinforcing material 1 covered with the penetrating material 2, while performing the injection work into the inserted excavation hole 20, at another place, Using the extracted casing outer tube 10c, excavation work for another excavation hole is performed. That is, the injection operation and the excavation operation are performed simultaneously. By performing the work in this way, there is no waiting time during the work, and the construction time is shortened.
[0042]
(Other)
The lock bolt reinforcing member 1 of the above example has the opening at the tip end of the hollow passage 1h as a discharge port for the solidified material M. However, the discharge port for the solidified material M can be formed in the middle or midway through the wall. The penetrating material 2 may be divided into a plurality of pieces in the longitudinal direction. A multilayer material may be laminated in the thickness direction. When injecting the solidified material, a separate injection hose may be provided between the rock bolt reinforcing material 1 and the infiltration material 2 or may be injected through the injection hose as desired outside the infiltration material 2. It is possible.
[0043]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to reliably prevent the collapse of the hole wall of the excavation hole, and to perform the excavation work of the ground and the injection work of the solidified material in parallel. Can be.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first example of a rock bolt reinforcing material covered with a penetrating material.
FIG. 2 is a view showing a second example of a rock bolt reinforcing material covered with a penetrating material.
FIG. 3 is a sectional view taken along the line III-III of FIG. 2;
FIG. 4 is a sectional view of FIG.
FIG. 5 is a view showing an injection path of a solidifying material formed in a penetrating material.
FIG. 6 is a front view showing a shoe member attached to a tip of a lock bolt reinforcing member.
7 is a view of the shoe member as viewed from the direction of VII shown in FIG.
FIG. 8 is a diagram showing a first operation procedure in a first example of placing a lock bolt reinforcing material.
FIG. 9 is a view showing a second operation procedure in a first example of placing a lock bolt reinforcing material.
FIG. 10 is a diagram showing a third operation procedure in a first example of placing a lock bolt reinforcing material.
FIG. 11 is a diagram showing a fourth operation procedure in a first example of placing a lock bolt reinforcing member.
FIG. 12 is a diagram showing a fifth operation procedure in a first example of placing a lock bolt reinforcing material.
FIG. 13 is a view showing a sixth operation procedure in the first example of placing the lock bolt reinforcing member.
FIG. 14 is a diagram showing a first operation procedure in a second example of placing a lock bolt reinforcing member.
FIG. 15 is a diagram showing a second operation procedure in a second example of placing a lock bolt reinforcing material.
FIG. 16 is a view showing a third operation procedure in a second example of placing a lock bolt reinforcing material.
FIG. 17 is a diagram showing a fourth operation procedure in the second example of placing the lock bolt reinforcing member.
FIG. 18 is a diagram illustrating a fifth operation procedure in the second example of placing the lock bolt reinforcing member.
FIG. 19 is a diagram showing a sixth operation procedure in the second example of placing the lock bolt reinforcing member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Rock bolt reinforcement, 2 ... Penetration material, 3 ... Shoe member, 10 ... Double pipe rod, 11 ... Drilling rod, 20 ... Drilling hole, G ... Ground, M ... Solidified material.

Claims (5)

In the ground reinforcement method by the rock bolt which drives plural rock bolt reinforcements to the ground to be reinforced,
Forming a drilling hole in the ground with a drilling pipe, inserting a rock bolt reinforcing material in the drilling pipe, and a tubular infiltration material that covers the same and directly faces the drilling hole so that the solidified material can penetrate and permeate,
A solidifying material is injected into the excavation hole, penetrates into the voids of the penetrating material, and the reinforcing material is fixed to the ground via the outer peripheral surface thereof. Performed before the hardening of the material,
A ground reinforcement method characterized in that the excavation pipe used for the excavation hole is used for excavation work for another excavation hole at the same time as the injection work for the excavation hole. A hollow channel is formed in the reinforcing material, a solidified material is supplied through the hollow channel and discharged to the outside, the solidified material is injected into a drilling hole, and the solidified material is permeated into the voids of the penetrating material, The ground reinforcement method according to claim 1, wherein the ground is fixed to the ground via the outer peripheral surface. The osmotic material may have some flexibility, is in a form that itself exhibits shape retention and prevents collapse of the pore walls, and with respect to permeation and permeation of the solidified material, The ground reinforcement method according to claim 1 or 2, wherein the material and the shape are materials and shapes that can penetrate and permeate the inside and inside and outside surfaces of the material. The ground reinforcing method according to any one of claims 1 to 3, wherein the reinforcing material and the tubular penetrating material covering the reinforcing material are simultaneously inserted into the excavation hole. The reinforcing material and the tubular penetrating material covering the reinforcing material are simultaneously inserted into the excavation hole in a state in which the tip of the tubular penetrating material is integrated with the tapered shoe material having a higher strength than the penetrating material. The ground reinforcement method according to any one of Items 1 to 4.

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