Bundle nail method of poor ground stabilty

Abstract

The present invention relates to a bundle nail method for ground stabilization with an improved structure that integrates the soil inside the ground with the soil on the outer surface of the ground using bundle nails, thereby reinforcing unstable ground and reducing construction costs. The method comprises a first step of drilling multiple boreholes into the ground of the construction section at spaced-apart locations; a second step of inserting a bent end of a bundle nail into each of the multiple boreholes and arranging the other end of the bundle nail to cover the ground surface; a third step of injecting a grouting material containing cement into each borehole into which the end of the bundle nail is inserted and hardening it; a fourth step of fixing multiple bundle nails through a fixing plate placed on the ground where the boreholes are located; and a fifth step of fixing reinforcing bars by applying pressure through a pressure plate bolted to the upper side of the fixing plate. According to this, the present invention allows for the convenient simultaneous construction of reinforcement works for ground stabilization both inside and outside the ground, thereby enabling sufficient reinforcement against vertical and shear stresses with a simple structure and providing the useful effect of improved constructability.

Description

Technology Field

[0001] The present invention relates to a bundle nail method for ground stabilization that integrates the soil inside the ground with the soil on the outer surface of the ground using bundle nails according to the characteristics of the unstable ground, thereby maximizing the stability rate of the unstable ground compared to general reinforcing materials while lowering construction costs. Background Technology

[0002] Generally, existing ground reinforcement methods include the gravity soil nail method, CIP (Cast In Concrete Pile) method, micro pile method, and LW (Labiles Wasserglass) method.

[0003] Existing ground reinforcement methods focus on ensuring the stability of vertical stress within the unstable soil. However, these methods consider only vertical stress and neglect shear stress.

[0004] Generally, when critical failure of the ground occurs, the failure is not caused solely by vertical stress, but rather by the simultaneous action of vertical and shear stresses; therefore, the design must consider both forces simultaneously.

[0005] Furthermore, when critical failure occurs due to ground behavior, the failure direction is vertical and horizontal. However, existing ground reinforcement methods only consider vertical stress, so they are ineffective against horizontal failure. This is because a single reinforcing bar (D=22~32mm) is used in each borehole during construction, leading to shear failure if excessive shear stress is applied to the bar.

[0006] Therefore, existing ground reinforcement methods have the disadvantage of reduced constructability and high construction costs because they increase the safety factor by increasing drilling depth or narrowing the spacing of reinforcing bars during design.

[0007] Therefore, it is necessary to simultaneously implement internal and external ground reinforcement methods to increase resistance to vertical and shear stresses. Prior art literature

[0008] Patent Registration No. 1024362 The problem to be solved

[0009] The present invention is proposed to address the aforementioned problems, and its purpose is to provide a bundle nail method for ground stabilization that allows for the simultaneous construction of internal ground reinforcement and external ground reinforcement methods to increase resistance to vertical and shear stresses. means of solving the problem

[0010] The present invention for achieving the above-mentioned purpose comprises a first step of drilling a plurality of bore holes into the ground of a construction section, and

[0011] A second step of installing and assembling a steel wire on a bundle nail equipped with an anchoring reinforcing member according to the length of the tip reinforcing member or steel wire, and

[0012] A third step of inserting a bent end of a bundle nail into each of the plurality of boreholes and installing the other end of the bundle nail so that it is positioned horizontally with respect to the ground surface and connected to another borehole, and

[0013] A fourth step of injecting grouting material into each bore hole into which one end of the bundle nail is inserted, and

[0014] A fifth step of fixing the bundle nail by binding different nail reinforcing bars into one using a binding member formed on the upper surface of a fixing plate placed in the ground where the above-mentioned drilled hole is drilled, and

[0015] It is characterized by having a sixth step of stabilizing the ground by tensioning a steel wire on an auxiliary pressure plate of a fixed bundle nail.

[0016] In addition, after the sixth step, the method further comprises a step of applying pressure and fixing through a pressure plate on the upper side of the fixed plate.

[0017] The step of pressing and fixing the pressure plate on the upper side of the above-mentioned fixing plate involves fastening the fixing plate and the pressure plate with bolts to apply pressure to the fixing plate using the fastening force of the bolts. Effects of the invention

[0018] The present invention utilizes a bundle nail to integrate the soil within the ground with the soil on the external surface, thereby reinforcing unstable ground and reducing construction costs through an improved structure. Accordingly, since the present invention allows for the convenient simultaneous construction of reinforcement work for ground stability both inside and outside the ground, it provides the useful effect of achieving sufficient reinforcement against vertical and shear stresses with a simple structure and improving constructability. Brief explanation of the drawing

[0019] FIG. 1 is a construction state diagram showing the installation of a bundle nail construction structure according to the present invention. FIG. 2 is an external plan view of the ground illustrating a bundle nail construction structure according to the present invention. Figure 3 is a cross-sectional view of the tip reinforcement and the anchoring reinforcement. FIG. 4 is an external plan view of the state in which the pressure plate is combined. FIG. 5 is a flowchart showing the sequential construction sequence of the bundle nail method according to the present invention. Specific details for implementing the invention

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0021] A bundle nail method for ground stabilization according to the present invention, described with reference to FIGS. 1 to 5, comprises: a first step (S1) of drilling a plurality of holes (3) into the ground (1) of a construction section; a second step (S2) of installing and assembling a steel wire on a bundle nail having a tip reinforcing member or an anchoring reinforcing member installed according to the length of the steel wire; a third step (S3) of inserting a bent end of a bundle nail into each of the plurality of holes (3) and installing the other end of the bundle nail so that it is positioned horizontally with respect to the surface of the ground (1) and connected to another hole; a fourth step (S4) of injecting a grouting material into each of the holes (3) into which the end of the bundle nail is inserted; and fixing the bundle nail by binding different nail reinforcing bars together using a binding member (13) formed on the upper side of a fixing plate (11) placed in the ground (1) where the holes (3) are drilled. It consists of a fifth step (S5) and a sixth step (S6) of stabilizing the ground by tensioning the steel wire on the pressure plate (17) of the fixed bundle nail.

[0022] To explain in more detail, the bundle nail inserted into the perforated hole (3) is formed by binding together multiple nail reinforcing bars (7) that are spaced apart from each other through a spacer (5).

[0023] Additionally, the bundle nail is bent at a 90° angle at one end and the other end so that the one end (rear end) is inserted into the interior of the drill hole (3), a tip reinforcing member (30) is attached to the tip, and the remaining other end (tip end) is positioned horizontally with respect to the surface of the ground (1) to be connected to another drill hole (3).

[0024] That is, the bundle nail is manufactured by taking into account the length from the end portion inserted into the interior of the bore hole (3) to the other end portion placed on the surface of the ground (1) and placed to another bore hole (3), and if the length of the bundle nail is long depending on the length of the bore hole, it is manufactured by providing a fixing reinforcement member (20) in the middle portion.

[0025] The tip reinforcing member (30) and the anchoring reinforcing member (20) have a steel wire anchoring member (40) drilled in the center and a plurality of reinforcing member anchoring members (50) drilled around it so that a nail reinforcing bar is inserted.

[0026] A tip reinforcing member (30) is coupled with a tip reinforcing member lid (60), and a steel wire is coupled to the tip reinforcing member lid (60).

[0027] The above-mentioned fifth step (S5) involves the process of binding multiple different nail reinforcing bars (7) into one using a band-shaped binding member (13) placed on the upper side of the fixing plate (11).

[0028] The binding member (13) has a middle portion integrated with the upper surface of the fixing plate (11) and both ends bent to form a band shape, and has a structure in which the other end of the nail reinforcing bar (7) and the middle portion of another nail reinforcing bar (7) are accommodated between the two ends and the middle portion.

[0029] In addition, a seventh step (S7) may be further provided, in which the entire bundle nail is secondarily pressure-tensioned into a steel wire through a pressure plate (17) on the upper side of the fixing plate (11) after the sixth step (S6).

[0030] Next, protective works such as slope protection (green soil, core net, seed spray, shotcrete seed spray, concrete block, rockfall prevention net, etc.) or ground (1) reinforcement (distribution reinforcement, lean concrete, foundation concrete, etc.) are constructed on the surface of the ground (1) of the construction section. Here, a known cement milk liquid composed of cement + water + admixture is used as the grouting material. The fixing plate (11) has a plate shape with a hollow formed in the center so that the nail reinforcement (7) can pass through it. The pressure plate (17) has a plate shape placed on the upper side of the fixing plate (11) and preferably has a larger volume than the fixing plate (11). The pressure plate (17) and the fixing plate (11) have a structure in which a plurality of connecting holes (11b, 17a) with screw threads are formed on the inner surface and are connected via a bolt (15). The pressure plate (17) and the fixing plate (11) are connected during the process of fastening the bolt (15). The pressure of the pressure plate (17) is varied by the fastening force of the bolt (15). The grouting material injection process can be performed by injecting through an injection pipe (9) fixed to a spacer (5) that binds multiple nail reinforcing bars (7), or by inserting an injection pipe (9) for grouting material through the hollow of the fixing plate (11) and then injecting the grouting material. The construction process of the bundle nail involves inserting one end of the bundle nail into multiple boreholes (3) formed in a construction section such as a slope or flat land, and injecting the grouting material into the boreholes (3). As a result, one end of the bundle nail is fixed and the other end is fixed to a binding member (13) of the fixing plate (11) located above another borehole (3). At this time, the bundle nail is spaced at regular intervals by the spacer (5) so that the nail reinforcing bars (7) entering the boreholes (3) through the hollow of the fixing plate (11) from four directions. After binding, grouting is performed. As a result, the bundle nails are arranged in a grid pattern with the ends of multiple nail reinforcing bars (7) on the surface of the ground (1), and each end of the nail reinforcing bar (7) is inserted into the inside of the drilled hole (3) and grouted, thereby reinforcing the inside and outside of the ground (1) simultaneously.Afterwards, the nail rebar (7) can be fixed by fastening the pressure plate (17) to the upper side of the fixing plate (11) with a bolt (15) and pressing the binding member (13) that binds the end of the nail rebar (7) from the upper side.

[0031] Accordingly, the present invention is configured such that a portion of the bundle nail is inserted into the perforated hole (3) to reinforce the interior of the ground, and the remaining portion is arranged to cover the surface of the ground (1) to reinforce the exterior of the ground (1).

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[0041] delete Explanation of the symbols

[0042] 1 : Ground 3 : Drilling hole 5 : Spacer 7 : Nail rebar 11 : Fixed plate 11a : Hollow 11b,17a : Connector 13 : Binding piece 15 : Bolt 17 : Pressure plate

Claims

Claim 1 A bundle nail reinforcement tensioning method for ground stabilization, characterized by comprising: a step of drilling a plurality of boreholes into the ground of a construction section; a step of assembling a bundle nail integrally by pre-binding a steel wire to a bundle nail having a tip reinforcement or an anchoring reinforcement installed in the middle section according to the length of the borehole; a step of inserting one end of the bundle nail, bent at 90°, into each borehole and installing the other end so that it is continuously arranged in a grid shape along the ground surface to another borehole; a step of injecting a grouting material into the borehole to anchor the one end of the bundle nail inside the ground; a step of binding and fixing the other ends of different bundle nails in an intersecting arrangement at a single pressure point by means of a band-shaped binding member formed on the upper side of a fixing plate placed on the ground surface; and a step of tensioning the steel wire against the pressure plate of the bound bundle nail to simultaneously tension and pressure reinforce the internal anchoring part of the ground and the external surface part. Claim 2 A bundle nail reinforcement tensioning method for ground stability according to claim 1, characterized in that the tip reinforcement and anchoring reinforcement are provided with a steel strand anchoring member in the center and a plurality of reinforcing member anchoring members around the circumference, so that the steel strand and a plurality of nail reinforcing bars are simultaneously and integrally anchored. Claim 3 A bundle nail reinforcement tensioning method for ground stabilization according to claim 1 or claim 2, wherein the bundle nail is configured such that a spacer and a grouting injection pipe are combined between a plurality of nail reinforcing bars, so that each nail reinforcing bar maintains a uniform spacing within the bore hole and a grouting material is uniformly injected through the spacer. Claim 4 A bundle nail reinforcement tensioning method for ground stabilization according to claim 1, wherein the fixing plate includes a central hollow and a plurality of coupling holes, the pressure plate has a larger area than the fixing plate, and provides variable pressure to the nail reinforcement cross-binding portion on the ground surface according to the fastening force of the bolt. Claim 5 A bundle nail reinforcement tensioning method for ground stability according to claim 1, characterized in that the other end of the bundle nail is arranged to be connected to a bore hole in a different direction on the ground surface, thereby increasing the external ground reinforcement force and surface pressure dispersion effect through a grid structure of multiple nail reinforcing bars formed on the ground surface.

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