JPH04323496A - Stabilizing method for working face and device thereof - Google Patents

Abstract

PURPOSE:To be expected anchor-bolt-like effect, contribute to stability of working face, hereby contribute to prevention of displacement of ground surface and a collapse of natural ground and the like, and dispense with any work to strike the rearmost part of a core. CONSTITUTION:In a construction method for insertedly fitting a core into the center part of a pile as an improved body formed in the natural ground after injecting hardener with a horizontal hardener injecting device, the core is constituted out of a casing pipe 10. The core is a casing pipe capable of infinitely connecting by a thread means according to the required length to be struck in, and by the use of projection 14 for taking-in provided inside the casing pipe, it is struck in up to a prescribed place as a core, in case of an insertedly fitting rod, a drilling rod, a hardener injecting rod, or the like.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to the creation of foundations for improved structures on soft ground, and in particular to a face stabilization method and device for preventing collapse during horizontal pile excavation of tunnels, etc. It is.

0002

[Prior Art] Traditionally, in tunnel construction, an arch-shaped horizontal hardener injection method (hereinafter referred to as FP method) was used near the crown to prevent ground surface deformation, prevent ground collapse, and as a countermeasure against the face. It has been constructed. In this case, if the tunnel ground is very soft or if the excavation method is a full-section excavation method, there is extreme concern about the stability of the face if the FP method alone is used, so the following measures may be taken: Core material was driven horizontally inside an arch-shaped ground improvement body (pile) in a single-pit arrangement. That is, as shown in FIG. 6, by using a spiral drilling rod 51 at the center of the improved body 50 horizontally cast inside the arch, before or after the improved body is cured, the spiral groove formed therein is mechanically drilled. Alternatively, the core material was placed manually.

0003

[Problems to be Solved by the Invention] However, with the above-mentioned conventional techniques, not only was it time-consuming to cast the core material, but there were also many failures. In particular, the construction method required repeated excavation and core material driving, which was time-consuming and resulted in a large amount of expense. In addition, since the core material could only be driven a certain distance, when it became necessary to connect it, urethane, etc. was used for the connection part, but it was not effective enough as an anchor material for the connection part. There was no. Therefore, in view of the above drawbacks, the technical problem of the present invention is to provide an anchor bolt-like effect that can be connected easily, quickly, and economically as needed with certainty when driving a core material for stabilizing a face. The object of the present invention is to provide a core material having the following properties.

0004

[Means for Solving the Problems] According to the present invention, after injecting a hardening agent with a horizontal hardening agent injection device, a core material is inserted into the center of a pile which is an improved pile formed in a ground. In the construction method, the core material is a casing pipe, and the core material is a casing pipe that can be connected infinitely by screw means according to the required length to be driven, and the core material is provided inside the casing pipe. The retracting convex part allows insertion rods, drilling rods, hardening material injection rods, etc.
A face stabilization method and its device are obtained, which are characterized in that the core material is driven to a predetermined location.

[0005]

[Function] Since the core material is a casing pipe, the core material can be driven in simultaneously with an insertion rod or when using an excavation rod, a hardening agent injection rod, etc., so the above purpose can be achieved reliably or quickly. can be achieved.

[0006]

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a first embodiment of the present invention, and shows a state in which a casing pipe, which is a core material, is connected. That is,
One core casing pipe 10 has a bolt portion 12 at one end and a nut portion 11 at the other end, and both ends are threaded to function as a bolt and a nut. Therefore, as is clear from this figure, by threading two or more members together, it is possible to connect and extend the required distance. Experience has shown that the longer the core material, the more suitable it is as a so-called anchor material. This is because when conventional short core materials were connected using urethane, they were not effective as anchor materials.

The casing pipe 10 also has a retracting convex portion 14 at the tip of each member. Therefore, in the center of the ground improvement body formed in the ground, if the improvement body has not yet hardened, it can be left as it is, or if it has hardened, it can be inserted into the hole drilled with a spiral drilling rod using a pulling rod. A casing pipe can be inserted. Incidentally, since the casing pipe 10 needs to have an anchor bolt-like effect as a core material, glass fiber or plastic is preferable. This is because this core material needs to have excellent tensile properties to stabilize the face. However, the pipe 10 must have sufficient strength to be pulled into the ground as a drilling rod or injection rod excavates, and must be suitable for use with an excavator (backhoe) for excavating the inside of the tunnel. It is necessary that the material be made of a material that is weak enough to be crushed by. On the other hand, when excavating a face, it is required that the material be able to be easily excavated together with the ground, cut into small pieces, and discharged together with the waste.

FIG. 2 is a schematic sectional view showing the connected state of the casing pipe 10 and the retracted state by the excavating rod 15 according to the first embodiment. That is, it is an enlarged view of a state where the bolt part 12 and the nut part 11 are screwed together, and when the connected state is viewed from the outside, the connecting part 13 is visible only as a line, and there are no irregularities on the outside. Therefore,
There is no obstruction caused by the ground when it is pulled in,
It is inserted smoothly into the ground. Moreover, the retraction convex portion 14 provided inside is connected to the insertion stopper 16 provided one or more on the body portion of the excavation rod 15.
It will be hooked, and will be sequentially inserted or driven in as the rod advances. A foldable S-shaped bit 17 is provided at the tip of the excavation rod 15, so after excavating to a predetermined distance, the bit 17 is folded and the pipe is left inside the casing pipe 10. Then we returned to the tuyere. In that case, the diameter of the S-shaped bit 17 in the folded state is of course smaller than the hollow diameter of the casing pipe 10.

In the case of the casing pipe 10 shown in FIGS. 1 and 2 above, it is possible to use it as it is as a core material or anchor material, but especially in the case of soft ground, a hardening agent for the above-mentioned excavation rod 15 may be used. The casing pipe 10 can be reinforced by injecting a hardening agent into the casing pipe 10 using an injection rod. In this case, the curing agent must not be too strong, and the injection pressure of the curing agent must not be so-called ultra-high pressure. This is because in the former case, if the casing pipe is located inside the tunnel arch, the casing pipe must be crushed by an excavator (backhoe) during tunnel excavation, as will be described later. In the latter case, the casing pipe 10 will be crushed under so-called ultra-high pressure. However, if the casing pipe 10 is filled with a strong hardening agent, it will help improve or stabilize the ground outside the tunnel arch. In that case, the casing pipe 10 can be used as appropriate depending on the size of the diameter or the purpose. Further, the casing pipe 10 provided with a plurality of holes will be described later. In addition, in the case where the casing pipe 10 is pulled in using the insertion stopper 16 of the drilling rod and the casing pipe 10 is crushed and used as bone material, the rod is inserted into the pipe while injecting a hardening agent at an ultra-high pressure. The means for crushing the pipe while turning back inside the pipe has already been disclosed in an application filed by the same person on April 17, 1991.

FIG. 3 shows another embodiment of the face stabilizing device of the present invention, in which a plurality of holes 1 are suitably formed in the casing pipe 10.
8. If there are too many holes 18, the casing pipe 10 will become soft, or the jetting hardening agent will make the face too hard, making excavation work difficult. It is not suitable because there is a possibility. However, if such a casing pipe 10 is used to form a so-called arch-shaped ground improvement body 19 on a tunnel arch, a very strong ground improvement body can be formed. Furthermore, it can be said that it is preferable from the viewpoint of stabilizing the face portion. That is, when used as a core of an improved body that has already been formed, the center of the improved body will become stronger, and when used before the formation of the improved body, the casing pile 10 is attached to the hardener rod. As soon as the S-shaped bit is folded and retracted, the hardening agent is injected into the casing while rotating and moving backwards, and the hardening agent is also injected from the plurality of holes, making it possible to form a strong and unique improved body. However, in this case, it is desirable to use a casing pile made of a material that is not easily crushed. The means according to the present invention is a method in which the casing pipe 10 is not crushed by injecting a hardening agent, but the means for pulling out the injection rod while sequentially crushing the casing pipe while injecting an ultra-high pressure propellant from inside is a method described above. As shown, it is used in a separate invention belonging to the same applicant. Therefore, when the casing pipe according to this embodiment is used for face construction inside a tunnel arch, the plurality of holes 18 are generally
It is suitable to have smaller and fewer numbers than those outside the tunnel arch.

FIG. 4 shows the construction of an arch-shaped ground improvement body 19 and tunnel support 2 using the face stabilization method and device according to the present invention.
2 shows a state in which a face ground improvement body 20 is formed inside. These ground improvement bodies have a common feature of stabilizing the face, but because their ultimate purpose is different, they differ in size due to the different equipment or construction methods mentioned above. Next, we move on to face excavation, as shown in Figure 5.
As shown in FIG. 2, the face is excavated with an excavator (backhoe) 23, and the face ground improvement body 20 formed together with the casing pipe 10 is excavated and broken into small pieces together with the ground. The face ground improvement body fragments 21 are discharged together with shear.

FIG. 7 shows the state of formation of the ground improvement body 50 constructed by the conventional construction method shown in FIG. Since the conventional construction method is different from the construction method and device according to the present invention, there is no difference in the size of the external and internal ground improvement bodies of the tunnel arch.

[0013]

[Effects of the Invention] According to the present invention, an anchor bolt-like effect can be expected, which contributes to face stability, especially when the tunnel ground is particularly soft or when the tunnel excavation method is a full-section excavation method. Can be done. Achieving face stabilization also contributes to prevention of ground surface displacement, rock collapse, etc. Of course, this is an essential method for safety measures. Furthermore, in the conventional method, it was necessary to hammer in the last part of the core material, but with this method, such work is completely unnecessary, and overall, it is simple, quick, and economical. can achieve the intended purpose.

[0014]

[Brief explanation of drawings]

FIG. 1 is a first embodiment of the present invention, in which connected
It is a schematic sectional view of a casing pipe.

FIG. 2 is a schematic enlarged sectional view of the connecting portion of the first embodiment.

FIG. 3 is a second embodiment of the present invention, and is a schematic diagram showing a plurality of holes in the body part.

FIG. 4 is a schematic front view showing the tuyere after the construction of the ground improvement structure.

FIG. 5 is a schematic diagram showing the state of excavation of the face.

FIG. 6 is a schematic cross-sectional view of a conventional core material insertion method.

FIG. 7 is a schematic diagram showing a ground improvement body using a conventional construction method.

[Explanation of symbols]

10 Casing pipe 11
Nut part 12 Bolt part 13 Connecting part 14 Retraction convex part 15 Excavation rod 16 Fitting stopper 17 S-shaped bit 18 Hole 19 Arch-shaped ground improvement body 20
Face ground improvement body 21 Face ground improvement body fragments 22 Tunnel support 23 Excavator (backhoe) 50, 52
ground improvement body

Claims (3)

[Claims] Claim 1: In a construction method for inserting a core material into the center of a pile, which is an improved pile formed in the ground, after injecting a hardening agent with a horizontal hardening agent injection device, the core material is removed from a casing pipe. A face stabilizing device characterized by: [Claim 2] In the method for inserting a core material according to claim 1, the casing pipe can be connected infinitely by screw means according to the required length to which the core material is to be driven. A face stabilization construction method characterized in that the core material is driven into a predetermined location using an insertion rod, excavation rod, hardening agent injection rod, etc. through a drawing convex portion provided on the inside of the casing pipe. . 3. A face stabilizing device, wherein the casing pipe according to claim 1 has a plurality of holes at regular intervals.