Insert pipes, natural ground reinforcement method using the same and program

Abstract

To provide insert pipes, a natural ground reinforcement method using the same and a program, which can easily and surely save the labor of injection work for unexcavated natural ground of a tunnel, select a natural ground improvement material in water springing natural ground and perform the injection work.SOLUTION: An insert pipe 1 is used to a method of reinforcing natural ground by placing multiple long steel pipes 33 into an unexcavated natural ground 32 of a tunnel 31 and infiltrating a natural ground improvement material into cracks of peripheral natural ground through an inner space of the long steel pipe from discharge holes 33a provided at an outer periphery of the long steel pipe. In addition, a hollow cylindrical body 2 comprises packers 3 to divide an inside of the long steel pipe into multiple sections R1 to R3 and multiple injection tubes 4 with different length to inject the natural ground improvement material. Mouths of the multiple injection tubes detachably comprise flow meters 5.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to preliminary ground reinforcement work during tunnel excavation. [Background technology]

[0002] A known method of tunnel excavation is long steel pipe forepiling, in which long steel pipes are cast into the ground ahead of the tunnel and a ground improvement material is injected into the long steel pipe to improve the ground (see, for example, Figure 10). In long steel pipe forepiling, in ground with a lot of spring water, two types of ground improvement material may be used depending on the amount of spring water in the ground: a normal ground improvement material and a ground improvement material with excellent water-stopping performance. For example, Patent Document 1 shows a construction method in which the amount of spring water is measured for each injection hole and the ground improvement material is selected according to the amount of spring water. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-154319 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method in Patent Document 1 can measure the amount of spring water for each injection hole, i.e., the amount of spring water in the transverse direction of the tunnel, but cannot grasp the amount of spring water in the longitudinal direction, and it may be necessary to inject expensive water-stopping ground improvement material even in sections where the amount of spring water in the longitudinal direction is small, which results in high construction costs.

[0005] The present invention has been made to solve the above problems, and aims to provide an insert pipe that can reduce the labor required for injection work into unexcavated ground in tunnels and that can easily and reliably select and inject ground improvement materials into ground that is flooded, as well as a ground reinforcement method and program using the same. [Means for solving the problem]

[0006] The present invention is as follows. 1. An insert pipe used in a construction method in which multiple long steel pipes are installed in unexcavated ground in a tunnel, and ground improvement material is allowed to penetrate through the inner space of the long steel pipes and into cracks in the surrounding ground from discharge holes provided on the outer periphery of the long steel pipes, thereby reinforcing the ground. An insert pipe characterized in that a packer is installed in a hollow cylindrical body to divide the inside of the long steel pipe into multiple sections, and multiple injection tubes of different lengths are installed to inject ground improvement material, and flow meters are detachably installed at the mouths of the multiple injection tubes. 2. The insert pipe described in 1 above, characterized in that an openable and closable valve is installed at the mouth of the hollow cylinder to allow spring water to flow out from the mouth. 3. A ground reinforcement method comprising the steps of: driving a plurality of long steel pipes into the unexcavated ground of a tunnel; inserting an insert pipe into the long steel pipe; dividing the inside of the long steel pipe into a plurality of sections using packers attached to the insert pipe; measuring the amount of spring water in each of the plurality of divided sections using a flow meter installed at the mouth of an injection tube attached to the insert pipe; inputting the measured amount of spring water into the input section of an injection machine; selecting which of different types of ground improvement material to inject into the plurality of divided sections based on the input amount of spring water; and injecting the ground improvement material into the ground by controlling the injection according to the injection conditions of each selected ground improvement material. 4. A ground reinforcement method as described in 3 above, characterized in that it further comprises a step of identifiably displaying the selected different types of ground improvement materials in each injection section displayed on the management screen of the injection machine. 5. A program that causes a computer that controls an injection machine to perform the following processes: select which of different types of ground improvement material to inject into multiple injection sections within a long steel pipe cast into the unexcavated ground of a tunnel based on the amount of spring water flowing out from each of the multiple injection sections; and display the selected different types of ground improvement material in an identifiable manner for each injection section displayed on a management screen. [Effects of the Invention]

[0007] According to the present invention, the amount of spring water in the longitudinal direction of unexcavated ground in a spring-fed ground can be measured easily and quickly, and appropriate and economical injection work can be performed by selecting ground improvement materials according to the amount of spring water in each injection section. [Brief explanation of the drawings]

[0008] The present invention will be further described in the following detailed description, which provides non-limiting examples of exemplary embodiments according to the present invention, and with reference to the several figures mentioned, in which like reference numerals refer to like elements throughout the several views of the drawings. [Figure 1] 1A and 1B are explanatory views of an insert pipe according to an embodiment, in which FIG. 1A shows an assembled state and FIG. 1B shows a disassembled state. [Figure 2] 2A and 2B are enlarged cross-sectional views of the main part of FIG. 1, in which (a) is an enlarged cross-sectional view taken along line aa, (b) is an enlarged cross-sectional view taken along line bb, and (c) is an enlarged cross-sectional view taken along line cc. [Figure 3] FIG. 2 is a front view of the injection machine according to the embodiment. [Figure 4] 1 is a block diagram for explaining an injection machine. [Figure 5] FIG. 1 is a flowchart for explaining a natural ground reinforcement method according to an embodiment. [Figure 6] This is an explanatory diagram of the ground reinforcement method, where (a) shows the steel pipe casting process, (b) shows the insert pipe insertion process and the injection section division process, and (c) shows the spring water volume measurement process. [Figure 7] This is an explanatory diagram of the ground reinforcement method (ground improvement material display process). [Figure 8] This is an explanatory diagram of the ground reinforcement method (ground improvement material injection process). [Figure 9] 10A and 10B are explanatory views of a ground reinforcing step (ground improvement material display step) according to another embodiment, in which (a) shows a front view of the management screen, and (b) shows an enlarged view of a main part of (a). [Figure 10] This is an explanatory diagram of a typical ground reinforcement method, where (a) shows a longitudinal section along the tunnel axis direction, and (b) shows a cross section perpendicular to the tunnel axis direction. DETAILED DESCRIPTION OF THE INVENTION

[0009] The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of the embodiments of the present invention, with the aim of providing what is believed to be the most effective and easily understandable explanation of the principles and conceptual features of the present invention. In this regard, it is not intended to show structural details of the present invention beyond the extent necessary for a fundamental understanding of the present invention, and the description, taken together with the drawings, will make clear to those skilled in the art how some forms of the present invention may be actually embodied.

[0010] Hereinafter, the present invention will be specifically described by way of embodiments with reference to the drawings.

[0011] The insert pipe 1 of this embodiment is used in a construction method in which multiple long steel pipes 33 are cast into unexcavated ground 32 of a tunnel 31, and ground improvement material is allowed to penetrate through the inner space of the long steel pipes 33 and into cracks in the surrounding ground from discharge holes 33a provided on the outer periphery of the long steel pipes 33, thereby reinforcing the ground (see Figure 10).

[0012] As shown in Figures 1 and 2, this insert pipe 1 consists of a hollow resin cylinder 2, and is fitted around the outer periphery with a packer 3 that divides the interior of a long steel pipe 33 longitudinally into multiple (three in the figure) injection sections R1-R3, and multiple (three in the figure) injection tubes 4 of different lengths are installed so that their tips are positioned in each of the injection sections R1-R3. The packers 3 can be selected from those wrapped around sponge or cloth bags into which ground improvement material can be injected. A coupler 6 is provided at the end (mouth) of each injection tube 4, and a flow meter 5 is detachably attached to the coupler 6. The tip of an injection hose 12 (injection material) extending from an injection machine 11 (described below) is detachably connected to the coupler 6 (see Figure 8).

[0013] A rubber check valve 7 and a stopper 8 are installed at the rear end (mouth) of the insert pipe 1. When the insert pipe 1 is inserted into the long steel pipe 33, the rubber check valve 7 is inserted into the rear end of the long steel pipe 33, and the stopper 8 is fixed to the long steel pipe 33 by screwing it onto the male thread at the end of the long steel pipe 33. Each injection tube 4 is inserted through the rubber check valve 7. An openable valve 9 is installed at the rear end of the insert pipe 1 to allow the spring water in the insert pipe 1 to flow out from the rear end. Specifically, a cover 10 is attached to the rear end of the insert pipe 1, and the valve 9 is attached to the cover 10. Opening the valve 9 allows the spring water in the insert pipe 1 to flow out. The front end of the insert pipe 1 is open, but the rear end of the insert pipe 1 is closed by the cover 10 and the valve 9 in the closed state.

[0014] As shown in Figures 3 and 4, the injection machine 11 according to this embodiment is composed of a pump unit 13 for pumping a watertight ground improvement material M1, a pump unit 14 for pumping a general-purpose ground improvement material M2, and a control unit 15 for controlling the pump units 13 and 14. The ground improvement materials M1 and M2 are two-component mixed hardening type urethane-based or silica resin-based improvement materials. Therefore, two types of chemical solution of ground improvement materials M1 and M2 are mixed and supplied to each injection section R1-R3. Furthermore, the injection pumps 16 constituting each pump unit 13 and 14 are provided in pairs (three sets in the figure) so as to supply two types of chemical solution of ground improvement materials M1 and M2 to each injection section R1-R3.

[0015] The control unit 15 is equipped with a management screen 17 that collectively displays injection information (e.g., injection amount and injection pressure during injection) for each pump unit 13, 14. The control unit 15 also has control panels (operation panels) 18, 19 that start and stop the pump units 13, 14 and adjust the flow rate. The control unit 15 also has an input section 21, a selection section 22, a display section 23, and a control section 24, which will be described below. The control processing by the control unit 15 may be realized by either hardware or software, and the control device can be configured by preferably including a microcontroller (microcomputer) equipped with a CPU, storage device (ROM, RAM, etc.), input / output circuits, etc., at the center, and peripheral circuits such as an input / output interface.

[0016] The input unit 21 is composed of a touch panel screen or the like, and is used to input the number of the injection hole corresponding to the long steel pipe 33, the casting angle of the long steel pipe 33, the measured value of the amount of spring water measured by the flow meter 5, etc. (see step S4 in Figure 5).

[0017] The selection unit 22 selects whether to inject the water-stopping or general-purpose ground improvement material M1 or M2 into the injection sections R1 to R3 based on the input spring water volume (see steps S5 to S7 in Fig. 5). More specifically, the selection unit 22 selects to inject the water-stopping ground improvement material M1 into the injection sections R1 to R3 where the spring water volume is equal to or greater than a threshold value (e.g., 30 l / min), and selects to inject the general-purpose ground improvement material M2 into the injection sections R1 to R3 where the spring water volume is less than the threshold value.

[0018] The display unit 23 identifiably displays the watertight or general-purpose ground improvement materials M1 and M2 selected for each of the injection sections R1 to R3 displayed on the management screen 17 (see step S8 in FIG. 5). Specifically, as shown in FIG. 7, the display unit 23 identifiably displays, by color and / or pattern, which of the ground improvement materials M1 and M2 will be injected for each of the injection sections R1 to R3 that make up the layout plan 26, which simulates multiple long steel pipes 33. Furthermore, the display unit 23 identifiably displays, by color and / or pattern, which of the ground improvement materials M1 and M2 will be injected for each of the injection sections R1 to R3 that make up the table 27. Note that the layout plan 26 and the table 23 may both be displayed, or only one of them may be displayed. Furthermore, any color may be used for color identification. Furthermore, for pattern identification, different designs, letters, symbols, etc. may be used.

[0019] The control unit 24 independently controls the pump units 13 and 14 according to the injection conditions (e.g., injection amount, injection pressure, etc.) of the mountain improvement materials M1 and M2 (see step S9 in Figure 5). Specifically, the control unit 24 controls the injection of each pump unit 13 and 14 based on the injection amount, etc. set on the control panels 18 and 19.

[0020] Next, we will explain the natural ground reinforcement method using the insert pipe 1 configured as described above. As shown in FIG. 6(a), a long steel pipe 33 is cast into the unexcavated natural ground 32 in front of the outer periphery of the tunnel 31 using a known method (step S1 in FIG. 5). Next, as shown in FIG. 6(b), the insert pipe 1 is inserted into the long steel pipe 33 (step S2 in FIG. 5), and a rubber check valve 7 is fixed to the end of the long steel pipe 33 by screwing in a stopper 8. If a large amount of wellwater is present and high water pressure is applied to the insert pipe 1 during insertion, the valve 9 at the rear end of the insert pipe 1 is opened to allow the wellwater to flow out while the insert pipe 1 is inserted. Next, as shown in FIG. 6(c), with the valve 9 at the rear end of the insert pipe 1 closed, flow meters 5 are installed on the couplers 7 at the ends of the multiple injection tubes 4 to measure the amount of wellwater in each injection section R1 to R3 (step S3 in FIG. 5).

[0021] If the packer 3 is a bag-shaped cloth packer, ground improvement material is injected into the packer 3 through a packer injection tube (not shown) to expand the packer 3 before measuring the amount of spring water. Therefore, the process of dividing the packer into each injection section R1 to R3 is carried out after the process of inserting the insert pipe 1. In contrast, if the packer 3 is wrapped with sponge, the process of inserting the insert pipe 1 and the process of dividing the packer into each injection section R1 to R3 are carried out simultaneously.

[0022] Thereafter, the measured amount of spring water in each injection section R1 to R3 is input to the input unit 21 of the injection machine 11 (step S4 in Fig. 5). Next, depending on whether the input amount of spring water in each injection section R1 to R3 is greater than a preset threshold, the selection unit 22 of the injection machine 11 selects water-stopping ground improvement material M1 for injection sections R1 to R3 where the amount of spring water is greater than the set threshold, and selects general-purpose ground improvement material M2 for injection sections R1 to R3 where the amount of spring water is less than the set threshold (steps S5 to S7 in Fig. 5).

[0023] Next, as shown in Fig. 7, the display unit 23 displays the ground improvement materials M1 and M2 selected by the selection unit 22 on the management screen 17 in different colors and patterns for each of the injection sections R1-R3 in the layout diagram 26 and table 27 (step S8 in Fig. 5). Then, as shown in Fig. 8, the pump unit 13 is connected to the injection section R1-R3 for which the water-stopping ground improvement material M1 has been selected, and the injection hose 12 of the pump unit 14 is connected to the coupler 6 at the end of each injection tube 4 for the injection section R1-R3 for which the general-purpose ground improvement material M2 has been selected, and the ground improvement materials M1 and M2 are injected into each section (step S9 in Fig. 5). For example, if the amount of spring water is relatively high in area S1 and relatively low in area S2 in the unexcavated ground 32, the water-stopping ground improvement material M1 is injected into injection section R1, and the general-purpose ground improvement material M2 is injected into injection sections R2 and R3.

[0024] As described above, according to the insert pipe 1 of this embodiment, a packer 3 is installed in the hollow cylindrical body 2 to divide the long steel pipe 33 into multiple sections R1-R3. Multiple injection tubes 4 of different lengths are installed for injecting ground improvement materials M1 and M2. Flow meters 5 are detachably attached to the openings of the multiple injection tubes 4. This allows the injection sections R1-R3 into which different types of ground improvement materials M1 and M2 are injected to be selected based on the amount of spring water measured by the flow meters 5. The ground improvement materials M1 and M2 can be injected into the ground according to the selected injection conditions for each of the selected materials. As a result, the amount of spring water in the longitudinal direction of the unexcavated ground 32 in the spring water ground can be measured easily and quickly. This allows the selection of ground improvement materials M1 and M2 according to the amount of spring water in each injection section R1-R3, enabling appropriate and economical injection work.

[0025] Furthermore, in the insert pipe 1 of this embodiment, an openable and closable valve 9 for allowing spring water to flow out from the opening of the hollow cylindrical body 2 is installed. As a result, when there is a large amount of spring water and high water pressure is applied when inserting the insert pipe 1, the valve 9 can be opened to allow the spring water to flow out while inserting the insert pipe 1 easily and quickly.

[0026] Furthermore, the ground reinforcement method of this embodiment includes the steps of: driving a plurality of long steel pipes 33 into unexcavated ground 32 of a tunnel 31; inserting an insert pipe 1 into the long steel pipe 33; dividing the inside of the long steel pipe 33 into a plurality of sections R1 to R3 using a packer 3 attached to the insert pipe 1; measuring the amount of spring water in each of the divided sections R1 to R3 using a flow meter 5 attached to the mouth of an injection tube 4 attached to the insert pipe 1; inputting the measured amount of spring water into the input section 21 of the injection machine 11; selecting which of different types of ground improvement materials M1, M1 to inject into the plurality of sections R1 to R3 based on the input amount of spring water; and controlling the injection based on the injection conditions of the selected ground improvement materials M1, M2 to inject into the ground. This allows for easy and early measurement of the amount of spring water in the longitudinal direction of the unexcavated ground 32 in the spring water ground, and enables appropriate and economical injection work by selecting ground improvement materials M1 and M2 according to the amount of spring water in each injection section R1 to R3.

[0027] Furthermore, the ground reinforcement method of this embodiment further includes a step of identifiably displaying different types of ground improvement materials M1, M2 selected for each of the injection sections R1 to R3 on the management screen 17 of the injection machine 11. This makes it possible to identify the types of ground improvement materials M1, M2 to be injected into each of the injection sections R1 to R3 on the management screen 17. In particular, by using the layout diagram 26 that resembles the long steel pipes 33, it is possible to intuitively identify the types of ground improvement materials M1, M2 to be injected into each of the injection sections R1 to R3.

[0028] Furthermore, according to the program of this embodiment, the computer (control unit 15) that controls the injection machine 11 executes the following processes: select which of different types of ground improvement materials M1 and M2 to inject into multiple injection sections R1-R3 in a long steel pipe 33 cast into the unexcavated ground 32 of the tunnel 31 based on the amount of spring water flowing out of each of the multiple injection sections R1-R3; and display the different types of ground improvement materials M1 and M2 selected for each injection section R1-R3 on the management screen 17 in an identifiable manner. This enables appropriate and economical injection work by selecting the ground improvement materials M1 and M2 according to the amount of spring water in each injection section R1-R3. Furthermore, the type of ground improvement materials M1 and M2 to be injected into each injection section R1-R3 can be intuitively identified on the management screen 17.

[0029] It should be noted that the present invention is not limited to the embodiments and can be modified in various ways within the scope of the present invention depending on the purpose and application. That is, in the above-described embodiment, an example was given of a form in which it was clearly indicated which of the mountain improvement materials M1 and M2 should be injected in each of the injection sections R1 to R3 of the layout plan 26 that imitates a plurality of cast long steel pipes 33. However, as shown in Fig. 9, for example, it is also possible to adopt a form in which it is clearly indicated which of the mountain improvement materials M1 and M2 should be injected in each of the injection sections R1 to R3 (circular areas with different outer diameters) of the layout plan 26 in which injection holes are arranged along a semicircular section that imitates the cross section of the tunnel 31.

[0030] In addition, in the above embodiment, an example is given of a configuration in which the packer 3 divides the inside of the long steel pipe 33 into three injection sections R1 to R3, but this is not limited to this, and for example, a configuration in which the packer 3 divides the inside of the long steel pipe 33 into two or four or more injection spaces may be adopted.

[0031] In addition, in the above embodiment, an example was given of a form in which two types of ground improvement materials M1 and M2 are selectively injected depending on the amount of spring water in each injection section R1 to R3, but this is not limited to this, and for example, a form in which three or more types of ground improvement materials (for example, a combination of ground improvement materials for high water retention, water retention, and low water retention (general purpose)) are selectively injected depending on the amount of spring water in each injection section R1 to R3 may be adopted.

[0032] Furthermore, in the above embodiment, two-component mixing hardening type ground improvement materials M1 and M2 are exemplified, but the present invention is not limited to this, and for example, a ground improvement material that is not a two-component mixing hardening type may also be used.

[0033] In addition, in the above embodiment, an example is given of a form in which the insert pipe 1 is inserted into the long steel pipe 33 and then the flow meter 5 is installed in the coupler 6 of the injection tube 4, but this is not limited to this, and for example, a form in which the insert pipe 1 is inserted into the long steel pipe 33 with the flow meter 5 installed in the coupler 6 of the injection tube 4 may be adopted.

[0034] Furthermore, in the above embodiment, an example was given of a form in which the amount of spring water measured by the flow meter 5 is manually input into the injector 11, but this is not limited to this, and for example, a form may be adopted in which the flow meter 5 is equipped with a transmitting means and the amount of spring water measured by the flow meter 5 is transmitted (input) to the injector 11 by the transmitting means.

[0035] Furthermore, in the above embodiment, the program executed by the computer controlling the injection machine 11 may be in a form that is pre-stored (installed) in the memory unit of the injection machine 11, or may be in a form that is stored and provided on a storage medium such as a CD-ROM or USB memory, or may be in a form that is downloaded from an external device via a network.

[0036] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present invention. [Industrial Applicability]

[0037] The present invention is widely used as a technique for injecting ground improvement materials in advance ground reinforcement methods during tunnel excavation. [Explanation of symbols]

[0038] 1; Insert tube 2; Hollow cylinder 3; Packer 4; Injection tube 5; Flow meter 9; Valve 11;Injection machine 17;Management screen 31; Tunnel 32; Unexcavated ground 33;Long steel pipe 33a;Discharge hole M1: Water-stopping ground improvement material M2: General-purpose ground improvement material R1~R3: Injection section

Claims

1. An insert pipe used in a construction method in which a plurality of long steel pipes are cast into unexcavated ground in a tunnel, and ground improvement material is allowed to penetrate through the inner space of the long steel pipes and into cracks in the surrounding ground from discharge holes provided on the outer periphery of the long steel pipes, thereby reinforcing the ground. An insert pipe characterized in that a packer is installed in a hollow cylindrical body to divide the inside of the long steel pipe into multiple sections, and multiple injection tubes of different lengths are installed to inject ground improvement material, and flow meters are detachably installed at the mouths of the multiple injection tubes.

2. 2. The insert pipe according to claim 1, wherein an openable and closable valve is provided at the opening of the hollow cylindrical body to allow the spring water to flow out from the opening.

3. a step of inserting an insert pipe into the long steel pipe; a step of dividing the inside of the long steel pipe into a plurality of sections using packers attached to the insert pipe; a step of measuring the amount of spring water in each of the plurality of divided sections using a flow meter attached to the mouth of an injection tube attached to the insert pipe; a step of inputting the measured amount of spring water into the input section of an injection machine; a step of selecting which of different types of ground improvement material to inject into each of the plurality of divided sections based on the input amount of spring water; and a step of controlling the injection according to the injection conditions of each selected ground improvement material and injecting the ground improvement material into the ground.

4. The ground reinforcement method described in claim 3, further comprising a step of identifiably displaying the selected different types of ground improvement materials in each injection section displayed on the management screen of the injection machine.

5. A program that causes a computer that controls an injection machine to perform the following processes: select which of different types of ground improvement material to inject into multiple injection sections within a long steel pipe cast into the unexcavated ground of a tunnel based on the amount of spring water flowing out from each of the multiple injection sections; and display the selected different types of ground improvement material in an identifiable manner for each injection section displayed on a management screen.

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