JPH0515880B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a rock consolidation method for improving soft or crushed rock to a solid rock using a rock consolidation chemical. [Conventional technology] Conventionally, in geological zones such as soft rock (ground) or crushed ground, a roof is installed at the top of the tunnel face to prevent the top of the tunnel face from collapsing. Countermeasures have been taken such as the advance bolt method in which a hole is drilled along the arch of the board and a locking bolt is inserted into the hole or the bolt is solidified with mortar, the pipe roof method, and the chemical injection method. The mountain is being strengthened. However, this conventional method requires large-scale equipment, takes time to prepare machinery and injection, and has the disadvantage that on-site operations must be stopped for a considerable period of time for these operations. was occurring. [Problems to be Solved by the Invention] Therefore, in order to solve these difficulties, the present inventors installed a sealant (sealing material) such as cloth on one end side of the sealer made of a hollow pipe, and solved the problem described above. After impregnating the gasket with foamed resin such as urethane resin, the gasket is inserted from the other end into a hole previously drilled in the ground, and in this state, the urethane resin impregnated into the gasket is cured. A foam layer is formed around the packer to close the opening of the hole, and then urethane resin, etc. is press-fitted into the packer to fill the gap between the packer and the hole wall, and at the same time, the urethane resin is allowed to penetrate into the ground and harden. We have already proposed a method of solidifying the rock around the hole while leaving the pack car in the hole, and have already filed a patent application (Japanese Patent Application No. 58-144024 [Japanese Unexamined Patent Publication No. 60-33925]). . That is, in the above method (hereinafter referred to as the "conventional method"), as shown in FIG. The holes are drilled diagonally upward, and the packers 30 are sequentially inserted into these holes. As shown in FIG. By discharging two-component foamed urethane resin supplied from the hose 33 equipped with the unit 32, the holes are filled with urethane resin,
Furthermore, the urethane resin is infiltrated into the ground as shown in the figure and hardened to solidify the bedrock. In the figure, 34 is the shoring, and 35 is the consolidation area. To form a tunnel, the top plate 29 at the end of the tunnel face is hardened with hardened resin along the arch of the top plate, and in this state, the tip of the tunnel face is excavated, and after excavating a certain distance, The process of solidifying the top plate portion 29 is repeated. In this case, according to the conventional method, the top plate portion 29 is consolidated by both the packer 30 left in the hole and the consolidated area 35 distributed around it, as shown in FIG. Because of this, extremely strong consolidation is achieved. Furthermore, it has the advantage that large-scale equipment is not required because it does not require large machinery for construction, and because it is easy to consolidate, on-site work can be interrupted in an extremely short period of time. However, the above method uses a two-component foamed urethane resin that takes 3 to 5 minutes to harden after mixing the two components, so the packer 30 is inserted into the hole and the urethane resin is When press-fitting, it takes time for the resin that penetrates into the ground to harden, and the area where the resin penetrates becomes larger, and the amount of resin that remains uncured until the entire infiltrated resin is completely cured. The roof is more likely to collapse. That is, as mentioned above, the urethane resin that has penetrated into the ground is cured from the outer circumferential side of the resin infiltrated area, and the inside is in an uncured state, and the inside of the resin infiltrated area is cured by the uncured resin. In other words, it is in a state that contains water. Therefore, if the ground is particularly flexible, such as sand, it is likely to cause a collapse phenomenon. Therefore, for soft ground like the one mentioned above, concrete is sprayed on the roof surface before consolidation, but there are limits to such reinforcement, and it is practically impossible to strengthen especially soft ground. Construction is difficult. Further, according to the above construction method, the amount of resin used is large and it takes a considerable amount of time to press-fit the resin. That is, when press-fitting the urethane resin into the packer 30, if the urethane resin discharged from the tip of the packer 30 penetrates into the ground and hardens, the pressure required for press-fitting the resin will suddenly increase, so use this as a guideline. The longer the curing time of the urethane resin used, the greater the amount of resin liquid press-in and the larger the permeation area, which increases the injection time and amount of resin liquid used. be. Also,
When press-fitting the urethane resin, the packing 31 must be attached to the packing car 30 one by one, which is a complicated operation. Furthermore, since conventional rock consolidation methods use chemicals that take a long time to harden, leakage of chemicals through the ground to the front of the face is sometimes unavoidable, so concrete is sprayed onto the top surface prior to consolidation. The problem is that it takes a long time to construct. This invention was made in view of the above circumstances, and can be applied even to particularly soft rock such as sand, shortens the construction time, reduces the amount of resin used, and is easy to install. Its purpose is to provide a rock consolidation method. [Means for solving the problem] In order to achieve the above object, the rock consolidation method of the present invention involves drilling a plurality of holes at predetermined intervals in the ceiling part of the tunnel face along the arch of the ceiling. A lock bolt having a chemical discharge hole on the tip side is inserted into the hole up to the base and positioned, and a rock consolidation chemical is press-fitted into the lock bolt. A method of solidifying rock by filling the hole and infiltrating the rock, and hardening the rock solidifying chemical solution that fills the hole and permeates the rock while leaving a rock bolt in the hole,
The drilling of the multiple holes and the associated injection of the chemical solution are performed in several stages, and in the first stage, a predetermined number of the multiple holes are drilled at a large distance from each other. In the second step, separate holes are drilled between the holes drilled in the first step to inject the chemical solution, and for rock consolidation. The structure uses a fast-curing two-component foamed urethane resin as the chemical solution. In other words, in order to eliminate the drawbacks of the above-mentioned conventional method that we had proposed earlier, the inventors conducted further research and found that conventionally, if a resin with a too fast curing speed is used, the resin will deteriorate in a hollow pipe such as a car. We used a special two-component foamed urethane resin that had an extremely fast curing speed, which had been considered impossible to use due to the curing of When injecting, this is divided into several steps, and in the first step, a predetermined number of holes are drilled at wide intervals and the chemical solution is injected, and in the second step, separate holes are drilled between the holes. If you try to inject the drug,
It was discovered that construction is possible even on particularly soft rock such as sand. Furthermore, by using the special two-component foamed urethane resin mentioned above, it is possible to significantly shorten the construction time and at the same time reduce the amount of resin used.Moreover, the resin is discharged from the tip of the hollow pipe. When resin flows down near the opening of a hole, it hardens and closes the opening of the hole, so unlike the conventional method, a packing material, etc. is attached to the packer in advance to close the opening of the hole and prevent the resin from leaking. This invention was achieved by discovering that there is no need for complicated work. This invention uses a fast-curing two-component foamed urethane resin to solidify the rock by press-fitting it into a lock bolt inserted into a hole drilled in the rock. As the above-mentioned fast-curing two-component foam urethane resin, for example, the following liquids A and B may be mixed at a ratio of 1:1.
Products that are used in the industry and have an extremely short curing time of 5 to 30 seconds after mixing the two components are prized. The liquid A is a mixed liquid mainly containing a primary polyol having two or more hydroxyl groups, and is composed of a polyol liquid having a hydroxyl value of 250 to 450 KOHmg/g. Such polyol liquid usually has a hydroxyl value of 20 to 6400 KOHmg/g,
It is prepared by using a combination of several types of primary and secondary polyols having an average molecular weight of 18 to 5,000 and having two or more functionalities. In addition, the above B liquid is diphenylmethane-4,4'-diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI, crude
MDI) and tolylene diisocyanate (TDI)
Average molecular weight of at least one main component of 174
~2000, isocyanate group content 18~48% by weight
(hereinafter abbreviated as "%") of isocyanate liquid. To explain in more detail, the polyol components of the liquid A include polypropylene glycol, polyethylene glycol, trimethylolethane, trimethylolpropane, hexylene glycol,
Examples include alkylene glycols such as castor oil. Additionally, ethylene oxide and propylene oxide are added to glycerin, sorbitol, or sucrose, as well as ethylene oxide-propylene oxide copolymers, and amines such as ethylene diamine, diethanolamine, triethanolamine, and triethylene diamine. Examples include reactants with added . Particularly suitable are the following polyols. (1) Low molecular weight (molecular weight 60-1000), low viscosity (500 cps/25℃ or less), bifunctional or higher alkylene with a hydroxyl value of 50-2000 KOHmg/g, such as ethylene glycol, diethylene glycol, triethylene glycol, and dipropylene glycol. glycol. (2) Glycerin, sucrose, ethylene oxide,
Molecular weight with propylene oxide added: 500~
6000, a bifunctional or higher functional polyol with a hydroxyl value of 20 to 1000 KOHmg/g. (3) Ethylenediamine, triethanolamine,
Molecular weight of triethylenediamine with ethylene oxide and propylene oxide added
100-5000, hydroxyl value 20-1000KOHmg/g2
Polyols that are more than sensual. The isocyanate component of liquid B is polymeric MDI with an isocyanate group content of 30 to 31.5%,
Highly reactive diphenylmethane-4,4'-diisocyanate (isocyanate group content 32-34
%) of dimer, trimer formulations and crude MDI
and a low molecular weight (50-1000) polyol, such as ethylene glycol, diethylene glycol, dipropylene glycol, etc. (isocyanate group content 20-30%), and a dimer of the above diphenylmethane-4,4'-diisocyanate. ,
Examples include reactants of trimers and the above-mentioned low molecular weight polyols. The polyol component of the liquid A has a primary hydroxyl group, and its reactivity with isocyanate groups is very fast and active, but a catalyst may be added to further speed up the reaction rate. Examples of catalysts include aliphatic amines such as ethylenediamine, triethylenediamine, triethylamine, ethanolamine, diethanolamine, and dimethylethanolamine, aromatic amines such as 4,4'-diaminodiphenylmethane, dibutyltin dilaurate, and tin octylate. , tin chloride, lead octate, lead naphthenate, and other organometallic catalysts.
In addition, the improvement in the expansion ratio of urethane resin foam
Inert solvents such as trichloromonofluoromethane (CCl ₃ F), methylene chloride (C ₂ H ₄ Cl ₂ ), pentane, and water may be used, but from the viewpoint of the impact on workers, water is not recommended as a blowing agent. It is desirable to mainly use However, the methylene chloride mentioned above acts as a blowing agent, and at the same time,
10% or less of the total, preferably
It is preferable to use it within the range of 0.5 to 3%.
When using water as a foaming agent, add 0.1~
5% blending is performed. To increase the expansion ratio to 15 times, 1 to 4% water may be added. The above two-component foamed urethane resin consisting of liquid A and liquid B is heated at 0 to 30°C after mixing liquid A and liquid B.
It hardens in 5 to 30 seconds, and can be injected into a hole drilled in the ground using the conventional method proposed by the present inventors. When the lock bolt newly developed by the present inventors is used, the urethane resin does not harden in the middle of the hollow pipe such as the lock bolt.
This is suitable because it can be injected smoothly even into holes with a long depth. The rock bolts developed by the present inventors are of the driving type, in which urethane resin is injected after driving into a hole drilled in the rock with a rock drill such as a jumbo drill, and the rock bolt itself is a rock bolt that can be used with a rock drill such as a rock drill. There is also a self-drilling type. FIG. 1 shows a drive-in type lock bolt. This lock bolt consists of a lock bolt part 1 made of a hollow pipe with a closed end and a lock bolt main body 2 made of a hollow pipe, which are joined by a threaded joint 3. The length B of the lock bolt body 2 is set to 1 m, and the length C of the lock bolt body 2 is set to 2 m. Ten chemical liquid discharge holes 4 each having a diameter of 5 mm are formed on the outer periphery of the tip of the packer portion 1. On the other hand, police car part 1
A stepped portion 1a is provided at the rear end adjacent to the threaded portion, on which the stationary mixer 5 shown in FIGS. It is inserted and fixed with the tip facing toward the tip. The stationary mixer 5 has V-shaped double blades 5b tilted at regular intervals on the left half of the center about a linear central axis 5a extending forward (in the direction of arrow X) from the center of the root side ring portion 6. On the right half, single-layer blades 5c are tilted at regular intervals, and the urethane resin liquids A and B press-fitted into the lock bolt are received in the left and right halves, respectively, and both liquids are directed in the same direction (arrow A). , B directions). In this case, the right half has a single blade 5c, and the left half has a V-shaped double blade 5b.
is provided, and when the urethane resin rotates from the right half to the left half, the flow speed is increased by the action of the V-shaped double vane 5b, which is wide on the inlet side and narrow on the outlet side, and the urethane resin is transferred from the left half to the right half. When you return, it returns to its initial speed. In other words, liquids A and B are mixed while rotating in the same direction due to the difference in flow velocity between the left and right halves. Since both liquids are not mixed by colliding with each other at the intersection, they are mixed and sent forward while maintaining the initial flow velocity at the time of injection. In other words, the Rockvolt is equipped with such a special static mixer 5, which allows the extremely fast-curing urethane resin to be mixed and transferred without curing in the middle, and to be smoothly discharged from the tip. be. Further, as shown in FIG. 1, a joint 7 with a check valve is screwed to the rear end of the lock bolt main body 2 and has a one-touch connection mechanism (not shown) in its opening. As shown in Fig. 3, the lock bolts are inserted upward (angle θ = 10 to 20 The hose 11 with the connecting unit 10 can be attached to the joint 7 with a check valve at the rear end with one touch. In FIG. 3, reference numeral 12 denotes a urethane press-in pump that feeds liquids A and B of two-component foamed urethane resin into the hose 11. Figure 4 shows two types of self-drilling type lock bolts. The lock bolt shown in Fig. 4a is constructed by joining a packer part 1 and a lock bolt main body 2 with a threaded joint 3, but the tip of the packer part 1 is open, and a drill part (a drill part) (see Figure 5) 13 are fitted together. This drill part 13 has four blades 1 on the end surface of the tip.
4 are provided at 90° intervals in the circumferential direction, and a center hole 15 is formed in the center of the end face, and outer peripheral holes 16 are formed between the blades 14, respectively. Note that the joint 7 with a check valve is attached when the urethane resin is press-fitted. Since the other parts are the same as the lock bolt shown in FIG. 1, the same parts are given the same reference numerals. In the lock bolt shown in FIG. 4b, a drill part 17 is integrally formed at the tip of the packer part 1. In this case, the drill bit 1
8 is formed by bifurcating from the root,
The tips of the branched portions are each formed into a blade 19. An outer peripheral hole 20 is formed at the base of the branched blade 19. The other parts are the same as the lock bolt shown in Figure 1. This invention uses the above-mentioned rock bolt to solidify rock in the following manner. For example, if you are planning to drill a total of 13 holes at 70 cm intervals along the arch of the ceiling in the ceiling at the tip of the tunnel face and inject the chemical solution, first drill the holes in the ceiling as shown in Figure 6. Of the total 13 holes drilled in 8, 7 holes a, c, e,
Holes a, c, g, and m are drilled at intervals of 140 cm, and a chemical solution is injected to solidify the surrounding ground. Next, as shown in Figure 7, holes a, c, g, and i are drilled. , k, m, respectively six holes b, d, f, h, j, l
The rock is consolidated by drilling the adjacent holes a, c, e, g, i, k, and m so that the distance between them is 70 cm, and injecting a chemical solution to solidify the surrounding ground. I do. To explain in more detail, for example, when using a driving type lock bolt, first insert it into the top plate part 8 at the tip of the tunnel face along the top plate.
At intervals of 140 cm, as shown in Fig. 8, a, c,
A total of 7 holes 22 corresponding to e, g, i, k, m
(upwards at an angle of 10 to 20 degrees). and,
The lock bolts shown in FIG. 1 are inserted into the drilled holes 22, and a driving adapter 23 is attached to the rear end of the lock bolt main body 2 as shown in FIG. , then on the rear end of the lock bolt that was driven in,
As shown in FIG. 10, a fitting 25 with a check valve is attached, and a hose 11 with a connecting unit 10 is connected to it.
The connecting unit 10 is attached to the joint 25 with a check valve with one touch. Then,
From the hose 11, urethane resin liquid A and B
Inject the liquid into the lock bolt at a pressure of 15 to 20 kg/cm ² . The A and B liquids press-fitted in this way reach the threaded joint 3 in a laminar flow state, and after reaching the packer part 1, they are mixed by a static mixer 5 (see Figure 1). In this state, the chemical liquid is discharged from the chemical liquid discharge hole 4 at the tip of the lock bolt. In this case, the urethane resin liquid that is first discharged flows from the tip side of the hole 22 toward the opening, hardens in the process, and reaches a completely hardened state by the time it reaches the opening of the hole 22, closing the opening. Prevents leakage of discharged resin. Therefore, there is no need to use a gasket to close the opening of the hole 22 as in the conventional method. When the penetrating resin hardens, the injection pressure of the urethane injection pump suddenly increases.
Stop press-fitting the resin and remove the connection unit 10 with one touch. In this way, the lock bolt is inserted into hole 22.
The ground around the hole 22 is fixed with a hardened resin. This state is shown in FIG. In the figure, 26 is a consolidation area. In this way, the seven holes a, c, e, g, i, shown in FIG.
After inserting lock bolts into holes k and m and injecting a chemical solution to solidify the rock, next, in the same manner, hole No. As shown in the figure, six holes b, d, f, h, j, l
The rock is solidified by drilling a hole, inserting a lock bolt, and injecting a chemical solution. As a result, as shown in Figure 12,
Even if the ground is particularly soft, such as sandy ground, the top plate does not collapse, and the entire top plate part 8 is reinforced by the synergistic effect of the plurality of lock bolts and the surrounding consolidated areas 26. In addition, when using the self-drilling type rock bolts shown in FIGS. 4a and 4b, the lock bolts are attached to the rock drill 28 as a drill as shown in FIG. water from the air supply pipe 29a into the lock bolt,
Press the air into the center hole 1 at the tip of the lock bolt.
5. Discharge soil, sand, etc. from the outer circumferential hole 16, and move the soil, sand, etc. scraped by the blade of the lock bolt backwards along the outer circumference of the lock bolt, and discharge it to the outside from the opening of the hole. c, e, g, i, k,
A hole 22 corresponding to m is bored. In this way, use the rock bolt as a drill to form the hole,
Leave the lock bolt in the hole, then connect the check valve fitting 25 to the rear end of the lock bolt, and
As shown in the figure, a hose 11 with a connection unit 10
Connect the two-component foamed urethane resin with one touch, and press-fit liquids A and B of the two-component foamed urethane resin, and discharge them from the center hole 15 and outer hole 16 provided in the blade at the tip of the rock bolt, and solidify the rock in the same way as the driving type. Perform the knot (see Figure 15). Next, in the same manner as above, holes corresponding to b, d, , f, h, j, and l in FIG. 6 are drilled, and a chemical solution is forced into the rock bolt to solidify the rock. In this way, even if the ground is particularly soft, the roof section 8 at the tip of the tunnel face can be placed at predetermined intervals along the arch without causing the roof to collapse, as shown in Figure 12. A lock bolt is driven in, and a solidified region 26 of urethane resin is formed around the lock bolt, thereby reinforcing the top plate portion 8. In addition, although the above description describes the drilling of the plurality of holes a to m in two stages, the drilling may be performed in three or more stages. Further, when drilling a plurality of holes in several steps, instead of drilling one hole at a time as described above, it may be two holes, three holes at a time, or randomly. Furthermore, although the lock bolts are distributed within a range of 90° in Figure 12, they are not limited to this, but can be distributed at any angle within the range of 90 to 120°, and in some cases It is possible to distribute the angle at the angles above. [Effects of the Invention] As described above, the present invention divides the drilling of the holes into several stages when drilling a plurality of holes in the ceiling part at the tip of the tunnel face along the arch of the ceiling. In the first step, a predetermined number of holes among the plurality of holes are drilled at wide intervals so as not to have an adverse effect on each other when drilling the holes, and as a chemical solution to be press-fitted into the lock bolt, Since the curing process is fast, the amount of resin remaining in an uncured state is extremely small until the entire chemical solution is completely cured, so a chemical solution for rock consolidation is used that does not create a type of water-containing state due to the presence of uncured resin. The first stage of rock consolidation is performed, and then separate holes are drilled between the holes that were drilled in the first stage and the surroundings are solidified, and the rock is solidified in the same manner as the first stage. Since it performs consolidation, rock consolidation can be performed even on particularly soft rock such as sandy rock without causing a collapse phenomenon. Moreover, this invention
A two-component foamed urethane resin with a short curing time is used as the rock solidification chemical as described above, and in order to press-fit it into the rock bolt, the urethane resin discharged from the chemical discharge hole on the tip side of the rock bolt is It hardens as it flows from the tip of a hole drilled in the rock toward the opening, closing the vicinity of the opening of the hole and preventing leakage of the urethane resin that is subsequently discharged. Therefore, the complicated work of providing a packing on the lock bolt to close the hole, which is required in the conventional method, is no longer necessary. Moreover, since the injected resin properly penetrates into the bedrock and hardens quickly, there is no need to infiltrate a large amount of urethane resin into the bedrock in excess of the required amount, which was the case in the past, resulting in significant savings in the amount of resin used. It becomes possible to realize a significant reduction in resin press-fitting time. However, according to this invention, the width of the solidified area formed around the lock bolt becomes narrower, so as is clear from the comparison between FIG. 12 and FIG. Although the number of holes to be drilled and the number of lock bolts to be inserted into the holes are larger than in the conventional method, in this invention, the curing time of the urethane resin per lock bolt is shorter than in the conventional method. This makes it possible to significantly shorten the overall construction time.
Furthermore, since the amount of resin used per lock bolt is significantly smaller, even if the number of lock bolts increases, the amount of chemical liquid used is significantly smaller than in the conventional method. As can be seen from the comparison between Fig. 12 and Fig. 18 above, the diameter of the cylindrical solidified region formed around the lock bolt is smaller in this invention than in the conventional method, but the reinforcing effect is This is sufficient. In other words, in the conventional method, since the urethane resin cures slowly, the amount of resin liquid that permeates naturally increases and the diameter of the solidified area formed around the lock bolt increases, which wastes the urethane resin. It can be said that In addition, according to the method of the present invention, the urethane resin cures extremely quickly, so there is no leakage of the chemical solution through the ground to the front of the face, and therefore there is no need for concrete spraying as in the conventional method. It is possible to consolidate the rock mass, and it also has the effect of improving workability on soft rock mass. Next, examples will be described together with comparative examples. First, three types of A shown in Table 1 below were used as the A solution (polyol component) of the two-component foam urethane resin.
A liquid was prepared.

【table】

[Table] Ren oxide The properties of the above three types of liquid A are shown in Table 2.

[Table] In addition, three types of B liquids shown in Table 3 were prepared as B liquids (isocyanate components).

[Comparative example]

If the construction target is a soft sandy ceiling part similar to that in Example 1, there is a risk of the roof collapsing. Therefore, a relatively strong ceiling part is targeted for construction, and the roof part is coated according to the conventional method. A total of 7 holes are drilled at 140cm intervals along the arch of the board, and a packer with a packer attached to the base is inserted into the hole to create a two-part urethane foam resin that hardens in 3 to 5 minutes after mixing the two parts. was injected to solidify the rock. The solidified state was as shown in Fig. 18. Table 4 shows a comparison of the hole drilling time, the two-component foam urethane resin injection time, and the total chemical solution (urethane resin) amount in Example 1 and Comparative Example.

[Table] As is clear from Table 4, in Example 1, the number of holes is large, so the drilling time is longer than in the comparative example. As a result, the total time required from drilling the hole to press-fitting was reduced to 210 mm compared to the comparative example.
117 minutes in Example 1, which is a 44% reduction. Moreover, the total amount of chemical solution is lower than that of the comparative example.
The weight was 700Kg, whereas in Example 1 it was 208Kg, a decrease of 68%. From this, it can be seen that according to Example 1, it is possible to realize a significant reduction in construction time and a significant saving in the amount of chemical liquid used compared to the conventional method. Moreover, according to Example 1, when inserting a lock bolt into a hole and injecting a chemical solution, there is no need to attach a gasket to the lock bolt each time as in the comparative example, which eliminates the complexity of installing the gasket and improves workability. It is also possible to obtain the improvement effect of Example 2 Liquid A and Liquid B were used as chemical solutions. Rock consolidation was performed in the same manner as in Example 1 except for this. The results were almost the same as in Example 1, and extremely excellent effects similar to those in Example 1 were obtained. Example 3 Liquid A and Liquid B were used as chemical solutions. Rock consolidation was performed in the same manner as in Example 1 except for this. In this case as well, extremely excellent effects substantially similar to those in Example 1 were obtained. As described above, according to the method of the present invention, it is possible to target particularly soft top panels such as those made of sand, which are difficult or impossible to construct using conventional methods, and the construction time can be significantly shortened and the use of the material can be greatly reduced. It can be seen that it is possible to achieve a significant reduction in the amount of chemicals used for rock consolidation, and also to simplify the construction process.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a driving type lock bolt used in this invention, Fig. 2 a is a perspective view of a stationary mixer installed in the lock bolt, Fig. 2 b is a side view thereof, and Fig. 3 is a view of the lock bolt. An explanatory diagram of press-fitting resin, Fig. 4a is a longitudinal sectional view of a self-drilling type lock bolt, Fig. 4b is a longitudinal sectional view of another self-drilling type lock bolt, and Fig. 5 is a longitudinal sectional view of a self-drilling type lock bolt.
Fig. 6 and 7 are explanatory diagrams showing an example of construction of the present invention; Figs.
10 and 11 are explanatory diagrams of the construction procedure, FIG. 12 is a state diagram looking at the top plate at the tip of the tunnel face to show the construction state of one embodiment of the present invention, and FIG. 14 and 15 are explanatory diagrams of other examples of the construction shown in FIGS. 6 and 7, and FIG. 16 is a cross-sectional view showing the construction state of the conventional example.
FIG. 7 is a longitudinal sectional view thereof, and FIG. 18 is an explanatory diagram for individually showing the consolidated regions in FIG. 16. 1...Pack car part, 2...Lock bolt body,
3... Threaded joint, 4... Chemical liquid discharge hole, 22...
Hole, 26... Consolidation area.

Claims (1)

[Claims] 1. A plurality of holes are bored at predetermined intervals along the arch of the ceiling in the ceiling of the tunnel face, and in the holes,
A rock bolt with a chemical discharge hole on the tip side is inserted all the way to the base and positioned, and a rock consolidation chemical is press-fitted into the rock bolt, and after filling the hole with the rock consolidation chemical, it is allowed to penetrate into the rock. , a method of solidifying rock by hardening a rock solidification chemical solution that fills the hole and penetrates the rock while leaving a lock bolt in the hole, which method includes drilling the plurality of holes and accompanying thereto. The chemical solution is injected in several steps, and in the first step, a predetermined number of holes are drilled at a large distance from each other to inject the chemical solution, and in the second step Then, separate holes were drilled between the holes drilled in the first step above to inject the chemical solution, and fast-setting two-component urethane foam was used as the rock solidification chemical solution. A rock consolidation method characterized by the use of resin. 2. The rock consolidation method according to claim 1, wherein the fast-curing two-component foamed urethane resin has a curing time of 5 to 30 seconds after mixing the two components.