KR20050118318A - Soil reinforcement method - Google Patents

Abstract

The present invention is made of a lightweight glass fiber reinforced plastics (FRP) hollow pipe having a threaded projection and by using a reusable rubber packer to inject the grout, so that the wire mesh buried in the nail and shotcrete Since the nut for binding can be directly fastened to the soil nail, the structure and construction are simple, and the coal time powder generated after the pulverized coal combustion of cement and thermal power plant is mixed with the inorganic quickener, and the gel time and water cement ratio (W / C ratio) and the one-component inorganic quickener grout which can adjust the required strength, permeability and durability freely according to the mixing ratio of coal ash and cement can reduce the amount of cement and reduce the cost and minimize the environmental pollution. To underground excavation and slope ground reinforcement.

The present invention forms a primary shotcrete on the cut surface of the earth and sand and then drills the soil and inserts a nail into the inside, and a step of injecting grout into the drilling hole through the soil nail and an air injection-type tube type to block the entrance of the drilling hole. Step 2 grouting to install the rubber packer and pressurize the grout into the punching hole and to separate the packer and to fill the spot with grout. Fastening the nut to the top of the nail nail in sequence to connect the wire mesh and the nail nail, and the second shotcrete part to be buried in the wire mesh, excavating the soil in each step and repeat the above process have.

Description

Eco-friendly digging surface and slope ground reinforcement method {Soil reinforcement method}

The present invention can be injected into the grout using a rubber packer made of a lightweight and reusable rubber glass fiber reinforced plastics (FRP) hollow pipe having a screw-type projection that can tighten the nut in the ground order and reinforcement grouting By improving the binding structure of wire mesh embedded in small nails and shotcrete, it provides the convenience of construction and the coal ash powder generated after the pulverized coal combustion of cement and thermal power plant is mixed with the inorganic quickener gel according to the site conditions. The time and water cement ratio (W / C ratio) can be adjusted, and the one-component inorganic quickener grout that can freely adjust the required strength, permeability and durability according to the mixing ratio of coal ash and cement can reduce the amount of cement by reducing the cost. Eco-Friendly Excavating Surface That Minimizes Soil Contamination Due to Highly Alkali Cement It relates to a surface ground reinforcement process.

Soil Nailing, the most widely used method in Europe and the United States as a slope stabilization method, is a ground reinforcement method consisting of drilling, nail installation, cement milk grout filling, shotcrete placement, and excavation. The concept is that the torsion of the area reinforced by nailing acts as if it is an integrated retaining wall, thus maintaining stability on any slope that the reinforcement walls can assume.

In the construction by the small nail method, nail is inserted into the perforated hole, grouted cement milk into the perforated hole without pressure, and after installing the wire mesh on the wall, rebars are placed horizontally and vertically on the wire mesh. After pressing and fixing the rebar with a pressure plate and a nut fastened to the nail, the shotcrete is poured. On the other hand, the grouting should completely fill the inside of the perforated hole. Since gravity grouting is applied, the solidification time is long, and shrinkage occurs due to water / cement ratio (W / C ?? 45%). Six repeat groutings are required. Therefore, there exists a problem that workability falls.

Practical registration No. 337877 relates to a grouting method using a pressure grouting device for reinforcing the ground, wherein a plurality of injection holes are radially formed in a state in which the inlet hole is completely sealed with a quick expanding material. Pressure to reinforce the ground to maximize the ground reinforcement effect by filling the ground around the drilled hole and the hole that is relaxed during drilling using fiber type, FRP pipe, steel pipe, PVC pipe and high pressure hose. It relates to a pressure grouting method using a type grouting device.

However, the pre-registered conventional pressure grouting method is composed of a simple cylindrical pipe made of FRP injection pipe installed inside the reinforcing fiber by the full winding method, so that the binding force with the grout filled is weakened so that it has releasability. When the reinforcement is weakened and the lattice-type wire mesh and the injection tube are bound, a separate bolt part has to be manufactured and fastened to the nut, thereby degrading the workability. And because the packer blocking the hole is a fast expanding material, it is impossible to reuse, and since the grout and releasable material are injected, there is a weakening of the binding force. Soil and groundwater were contaminated due to environmental pollution of cement, which adversely affected plant growth.

Slope reinforcement Patent Publication No. 2001-0086663 is a local that may occur due to the decrease of the strength of the ground and the progress of weathering due to the penetration of rainwater or snow melt into the cut slope reinforced with structural materials such as rock bolts, small nails, FRP, etc. It relates to a slope reinforcement device and method using a connection wire that can prevent phosphorescent collapse or rockfall.

However, this also requires a separate bolt that binds the reinforcement and the wire mesh has a disadvantage such as poor workability and not remove the toxicity of the grout cement.

The present invention was developed in view of the conventional problems, and an object of the present invention is to manufacture a rubber nail with a lightweight FRP (fiberglass reinforced plastics) hollow pipe having a threaded protrusion to fasten a nut and a rubber packer that can be reused. It is possible to pressurize grout to make it possible to fasten the nut for binding the wire nail embedded in the small nail and shotcrete directly to the small nail, so the construction is simple and the coal ash generated after the pulverized coal combustion of cement and thermal power plant The powder is mixed with the inorganic filler to adjust the gel time and water cement ratio (W / C ratio) according to the site conditions, and the one-component inorganic grade that can freely adjust the required strength, permeability and durability according to the mixing ratio of coal ash and cement. The use of payment grout reduces the amount of cement used, reduces the cost, and minimizes environmental pollution. Is environmentally friendly drilling surface and surface ground reinforcing construction method that can be to provide.

In order to achieve the above object, the present invention forms a primary shotcrete on the cut surface of the earth and sand, and then drills the soil and inserts the nail into the inside, and the first step of injecting grout into the boring hole through the soil nail and the drilling hole. Install air-injection tubular rubber packer to block the inlet, pressurize the grout into the drilling hole, separate the filling step, and remove the packer and the third step grouting, fill the place with grout, install the wire mesh on the primary shotcrete, and install the wire mesh Fasten the pressing plate and nut to the top of the nail nail in order to connect the wire mesh and the nail nail, and pour the secondary shotcrete so that the wire mesh is buried. There is a characteristic made.

Hereinafter, the preferred embodiment of the present invention will be described in detail.

1 is a cross-sectional view showing the ground reinforcement method of the present invention, Figure 2 is a cross-sectional view showing a rubber packer of the ground reinforcement method of the present invention. Earth and sand reinforcement method of the present invention is made in the following order.

In order to reinforce the cut surface of the earth and sand 1, the primary shotcrete portion 7 is poured into the cut surface at a predetermined thickness. Thereafter, a plurality of punched holes 2 are drilled where necessary, and the small nail 3 manufactured according to the present invention is inserted into the punched hole 2. Then, the grout is injected into the punching hole 2 through the hollow soil nail, and then the first grouting is performed to fill a predetermined amount, and then the inlet of the punching hole is blocked with a rubber packer 6 expanding inward and outward. The rubber packer 6 is in the form of a reusable tube and opens the valve 6a and injects high pressure air into the hose 6b to expand the packer to block the inlet of the hole 2. At this time, the front end of the small nail (3) serving as the inlet for grout injection to the center of the packer should be to protrude to the outside of the soil (1).

After the first grout, the packer (6) is installed and the second grout is performed. At this time, since the inlet of the punching hole 2 is blocked by the rubber packer, the grout can be pressurized and injected into the grout without filling pores in the punching hole. After the second grout, remove the packer (6) and perform the third grout. The third is to fill the place where the packer was located, whereby the entire hole (2) is tightly filled by the grout of the same physical properties.

Soil nail (3) is a hollow pipe formed with a threaded projection (4) for fastening the nut on the outer peripheral surface is made of a fiberglass reinforced plastics (FRP) pipe.

4 is a process chart showing a manufacturing process of the nail, the small nail 3 is produced through the drawing process. When the fibers 13 of the rolled state are drawn out and passed through the resin impregnation unit 14, the fiber strands are impregnated in the resin, and when the fiber strands pass through the heating unit 16, the solidified nail nail 3 is completed. And the heating unit 16 is further provided with a projection forming means (15) to pass through the spirally wound rope having elasticity on the outer circumferential surface of the small nail (3) to be passed. Since the rope passes through the heating part while the rope is wound, the outer diameter of the nail and the thread pitch of the projection 4 formed by the rope are kept constant. In addition, since the fibers are impregnated in the length direction, the small nails exhibit uniform tension and have a rough surface to reinforce the adhesive force of the grout. Loosening the wound rope after the formation of the protrusions 4 completes the nails, and these nails are cut to the required length.

On the outer circumferential surface of the small nail (3), a plurality of spacers (5) acting as a thumbnail should be installed so that the distance from the hole (2) is maintained. Since the small nail is positioned in the center of the hole (2) by the spacer (5), when the grout is injected and cured, the small nail serves as a central axis of the grout to serve as a grout reinforcing core material.

Grouts are made of cement, coal ash and one-part quickeners.

Coal ash, mostly burned in thermal power plants, is discharged from the boiler along with flue gas. At this time, the fly ash collected in the dust collector has a particle diameter of less than 10㎛ in 70 ~ 80% or more, and a large or large coal ash (10-15%) falling in the lower part of the boiler. It is called bottom ash.

In the present invention, these fly ash or bottom ash is pulverized into fine particles in a pulverizer after sorting and washing, and then screened by screening to powder. Fly ash is a complete mineral. Table 1 is a test report analyzing the chemical composition of the bottom ash.

[Table 1] KG Analysis Center Co., Ltd.

Trace ingredient chief ingredient Analysis item Analysis Analysis item Analysis pH [1:10] 9.61 SiO ₂ (%) 61.0 Pb (mg / kg) 35.2 Fe ₂ O ₃ (%) 6.06 Cd (mg / kg) 2.5 Al ₂ O ₃ (%) 17.3 Cu (mg / kg) 45.2 TiO ₂ (%) 0.65 Cr (mg / kg) 65.1 CaO (%) 10.11 As (mg / kg) trace MgO (%) 1.64 Hg (mg / kg) trace K ₂ O (%) 0.44 Zn (mg / kg) 50.5 Na ₂ O (%) 0.54 Ni (mg / kg) 60.2 Ignition loss (%) 2.1 Water Soluble Cl (%) 0.35 SO ₃ (%) 0.01 moisture(%) 0.34 * Trace: It shows below detection limit

As can be seen in Table 1, the bottom ash powder is inorganic and environmentally friendly since there is no harmful heavy metal such as mercury and arsenic. In addition, it has antibacterial, odor and insecticidal function by far infrared rays and is weak alkaline, so it can neutralize cement, eliminate odor and prevent groundwater contamination. It can reduce the amount of cement by increasing coal ash and recycle resources. There is a characteristic.

The present invention is a one-component inorganic alkali-based water glass-based, using a grout for ordering or ground reinforcement, and mixing the bottom ash coal ash with cement at a fixed ratio and a composition having the chemical composition of Table 2 as a fastener Used.

[Table 2] KG Analysis Center, Inc. May 5, 2004

Trace ingredient chief ingredient Analysis item Analysis Analysis item Analysis pH [1:10] 10.85 SiO ₂ (%) 2.22 Pb (mg / kg) 39.5 Fe ₂ O ₃ (%) 0.42 Cd (mg / kg) 1.8 Al ₂ O ₃ (%) 20.08 Cu (mg / kg) 10.5 TiO ₂ (%) 1.04 Cr (mg / kg) 105.4 CaO (%) 45.36 As (mg / kg) trace MgO (%) 0.36 Hg (mg / kg) trace K ₂ O (%) 0.77 Zn (mg / kg) 28.5 Na ₂ O (%) 2.73 Ni (mg / kg) 22.7 Ignition loss (%) 0.20 Water Soluble Cl (%) trace SO ₃ (%) 27.06 moisture(%) 0.12 * Trace: It shows below detection limit

As shown in Table 2, the fastener is environmentally friendly because no harmful heavy metals such as arsenic, mercury, etc. are detected. And it is mixed well with cement, coal ash and water, and the gel time and water cement ratio can be freely controlled, and it is easy to handle because it can carry out the field agitation and injection by carrying a certain unit packing. In addition, the fastener is easy to control the loss of ignition, it is easy to prevent the increase in viscosity to improve the fluidity, and to increase the durability of the densified tissue of the reaction material.

The grout used in the present invention is 50% by weight cement, 50% by weight of coal ash having a powder degree of 2400 ~ 5000 cm2 / g or more is compounded in a uniform ratio, the fastener is 3 to 5% by weight of cement, water cement ratio (W / C ) 50-70% by weight, gel time 20 seconds to 80 seconds.

If the formulation is suited to the required W / C ratio in the field and the amount of inorganic quickener is adjusted within the range of 3 to 5% by weight, the gel time can be freely adjusted at the site. If the W / C ratio is high, the gel time is delayed. Use it to improve the workability.

When grout is injected, it is injected into the center of hollow hollow nail (3), so no additional hose is required and pressure injection is possible, and after grout is discharged to the end of the nail, the hole (2) is continuously filled. Since it is injected into the air bubbles, the holes are filled tightly without generating bubbles.

After the grout is injected in three stages, the wire mesh 9 is disposed in a lattice form on the primary shotcrete portion 7, and the FRP hollow pipe connecting rod 11 and the FRP pressure plate 10 as shown in FIG. (3) and the nut 12 is fastened to the protrusion 4 of the nail nail 3 so that the pressure plate 10 can firmly press the wire mesh (9).

Then, when the secondary shotcrete portion 8 is poured, the wire mesh 9 is filled with the shotcrete, and the ground reinforcement method of the present invention is completed. Soil nail (3) to fill the drill hole (2) with the grout to act as a reinforcing core material can prevent the collapse of the soil.

5 is a block diagram showing the construction procedure of the present invention. Arrange the cut surface of earth and sand and cast the primary shotcrete to 75mm thickness. Then, drill a hole with a diameter of 105mm at the place where the small nail is inserted, insert the small nail, perform the first grouting, and block the entrance of the hole with a rubber packer. After that, secondary grouting is performed to inject grout into the front end of the small nail, and after removing the rubber packer, the place is filled with the third grouting. The wire mesh is then laid and the pressure plate and the nut are fastened to the nail nail to bind the wire mesh and the nail nail and pour the secondary shotcrete. Continue the excavation step by step and repeat the above process to complete the reinforcement of the excavation surface or slope.

The present invention uses a grout added with inorganic coal ash to reduce the soil environmental pollution of the cement can reduce the soil pollution and reduce the amount of cement. In addition, since the grout composition is a one-component type, it can be transported in a certain unit packaging, so it can be mixed with water as needed in the field. There is no such advantage.

As described above, according to the present invention, by manufacturing the soil reinforcement soil nails in light and corrosion-free FRP, handling is easy, and in particular, while the soil nails act as a reinforcing core material of the grout while injecting grout through the soil nails More effective for ground reinforcement And by forming a screw-shaped projection on the outer circumferential surface of the nail and processing the surface roughly, the adhesive force of the grout is strengthened and integrated, and the rubber packer bonded to the perforation hole can be reused, thus reducing the material cost and the projection of the nail Since the nut fixing the pressure plate can be directly fastened and fixed, there is an effect of simplifying the configuration.

Coal ash added to the grout is to reuse the waste from the power plant to recycle resources, reduce the amount of cement used to reduce costs, prevent soil contamination from the detoxification of cement and environmentally friendly effects that help plant growth. have.

1 is a cross-sectional view showing the ground reinforcement method of the present invention

2 and 3 is a cross-sectional view showing a packer of the ground reinforcement method of the present invention

Figure 4 is a schematic diagram showing a manufacturing process of the present invention nail

5 is a block diagram of the ground reinforcement method of the present invention

<Brief Description of Drawings>

1: earth and sand 2: drilling hole

3: small nail 4: protrusion

5: spacer 6: rubber packer

7: Primary shotcrete part 8: Secondary shotcrete part

9: wire mesh 10: pressure plate

11: connecting rod 12: nut

Claims (5)

After forming the primary shotcrete (7) on the cut surface of the earth and sand (1) and then drilled a hole (2) in the earth and sand to insert the nail nail (3) therein, First grouting step of injecting a certain amount of grout into the hole (2) through the inside of the nail nail (3), Secondary grouting step of installing air-filled tube-type rubber packer 6 to block the entrance of the drilling hole 2 on the outer circumferential surface of the small nail 3 and pressing and filling grout into the drilling hole 2 into the small nail 3. , A third grouting step in which the packer 6 is separated from the small nail 3 and filled with grout in place so that the perforation hole 2 is completely filled by grout of the same physical property, Install the wire mesh 9 in a lattice form on the primary shotcrete portion 7 and fasten the pressure plate 10 and the nut 12 that press the wire mesh 9 sequentially to the top of the nail nail 3 to form a wire mesh. (9) and the thumbnails (3) Eco-friendly excavation surface and slope ground reinforcement method, characterized in that consisting of the step of excavating the earth and sand and then repeating the above process by placing the secondary shotcrete (8) so that the wire mesh (9) is buried. The method of claim 1, Soil nail is made of FRP pipe and the outer peripheral surface is formed with a screw-type projection (4) for fastening the nut 12 and the adhesion of the grout, and the surface is made rough, so that the binding force of the grout is strengthened And slope ground reinforcement method. The method of claim 1, 50 to 100% by weight of cement, 50 to 0% by weight of ultrafine coal ash is blended in a uniform ratio, and 4% by weight of cement, 50 to 70% by weight of water cement ratio (W / C), gel time 20 to 80 Eco-friendly excavation surface and slope ground reinforcement method characterized by the prime. The method of claim 1, Soil nail (3) is impregnated with FRP resin while drawing the fiber, and solidified while passing through the heating portion, while passing through the heating portion while winding the rope is characterized in that the threaded projection (4) is formed on the outer peripheral surface with a uniform pitch Eco-friendly digging surface and slope ground reinforcement method. After forming the primary shotcrete (7) on the cut surface of the earth and sand (1) and then drilled a hole (2) in the earth and sand to insert the nail nail (3) therein, An air injection tube-type rubber packer 6 is formed on the outer circumference of the small nail 3 to block the inlet of the punched hole 2, and the grout is press-filled into the punched hole 2 into the small nail 3 to pack the packer 6 ), Install the wire mesh 9 in a lattice form on the primary shotcrete portion 7 and fasten the pressure plate 10 and the nut 12 that press the wire mesh 9 sequentially to the top of the nail nail 3 to form a wire mesh. (9) and the thumbnails (3) Eco-friendly excavation surface and slope ground reinforcement method, characterized in that consisting of the step of excavating the earth and sand and then repeating the above process by placing the secondary shotcrete (8) so that the wire mesh (9) is buried.