JPH0510479B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a stable construction method for excavating and constructing earth and sand tunnels with a low degree of consolidation in civil engineering work.

[Conventional technology and its issues]

When attempting to construct a tunnel in earth and sand or sandy ground, apart from the shield method, the problem with mountain tunnels is that the self-supporting time of the ground is extremely short. In this way, soil tunnels have low consolidation, so
It is not possible to cut and expand the required cross section all at once, and the work is forced to be divided into smaller cross sections to match the self-supporting time of the ground.

If the work is limited to a small cross-section in this way, cycle time loss due to preparation and curing, waste of materials, etc. will occur, which will have a major impact on the overall process.
There was no established technology for earth and sand tunnels yet.

In recent years, the shotgun lock bolt method (NATM method) has been used for mountain tunnels, and shotcrete, which is the main supporting member, may also be used in the case of earthy ground. However, the nozzles and other equipment used are extremely large, and if they are used as they are on a small cross-section as described above, the walls will be destroyed due to the high-pressure spraying, and the material will collapse together with the sprayed material, resulting in significant material loss. At the same time, it adversely affects the stability of the wall surface. Furthermore, the large nozzle cannot be operated as desired within the subdivided cross section, and it is impossible to spray at right angles to the ground, resulting in very poor workability as a whole.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
The purpose of the present invention is to provide a method for stabilizing the walls of earth and sand tunnels, which uses a small device, has good operability, and has a low degree of consolidation with little waste.

[Means to solve the problem]

In order to achieve the above-mentioned object of the present invention, when construction is carried out by dividing the required cross section of the earth and sand ground into small sections instead of cutting and widening them all at once, the side surface of the can-shaped storage section whose upper part is the opening for inputting material. The handle is attached, and the funnel-shaped bottom is bent so that the leading edge faces directly to the side, forming an injection nozzle. Immediately after this injection nozzle, there is a gap around it, and the tip of the air pipe faces out. This air pipe uses a hand sprayer connected to an air hose via an air pressure adjustment bubble, and uses the hand sprayer to spray a thin layer of hardening material such as mortar onto the face surface to solidify the cross section. The gist of this is to repeat the method of excavation.

[Effect]

According to the present invention, since a hand sprayer is used, spraying can be carried out at right angles to the ground, allowing construction even on small sections, and since the spraying pressure is low, there is no risk of wall destruction.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the construction method of the present invention, and FIGS. 2 and 3 are a side view of the hand sprayer used and a detailed view of the nozzle portion thereof.

First, to explain this hand sprayer 1 first, 2 in the figure is a can-shaped storage part with an opening 3 for inserting material at the top, a handle 4 is attached to the side, and a funnel-shaped bottom part is the top. The tip is bent so as to face right sideways, and the injection port 5 is formed here. Immediately after this injection port 5, the tip of an air pipe 6 faces with a gap around it, and this air pipe 6 is connected to an air hose 8 via an air pressure adjustment valve 7. The air hose 8 is connected to an air pipe (not shown) installed in the existing part of the tunnel.

As mentioned earlier, since the ground is sandy, it is impossible to cut and widen the required cross section all at once because the ground cannot stand on its own.

Therefore, the construction will be divided into small cross-sections that are adapted to the self-sustaining time of the ground, such as by excavating an advanced conductor.

When excavating a small diameter in this way, after excavating a suitable length, a thin layer of a consolidating material such as mortar is sprayed onto the face using the hand sprayer 1 to stabilize the wall surface. The setting material used is a mortar-based material mixed with a quick setting material and kneaded with a hand mixer 9. When the material in the storage section 2 is reduced, it is replenished from the opening 3 as appropriate.

Further, since the spray pressure can be adjusted by the valve 7, the work can be carried out while controlling the spray condition.

Not only the front of the face, but also the surrounding walls including the ceiling are stabilized with consolidating material, and the excavation is then returned to dryness.

〔Effect of the invention〕

As described above, the wall stabilization method for earth and sand tunnels with a low degree of consolidation according to the present invention can be carried out using small and simple equipment when construction is carried out by dividing the required cross section of the earth and sand into small sections without cutting and widening it all at once. It can be constructed freely even on small sections, reduces the loss of materials and time, prevents damage to the wall surface due to spray pressure, and allows the work to proceed efficiently.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing an embodiment of the wall stabilization method for earth and sand tunnels with a low degree of consolidation according to the present invention, Figure 2 is a side view of the hand sprayer used, and Figure 3 is a side view of the vertical nozzle section of the same. It is a diagram. 1...Hand sprayer, 2...Storage section, 3
...Opening, 4...Handle, 5...Injection port, 6...Air pipe, 7...Valve, 8...Air hose, 9
...Hand mixer.

Claims (1)

[Claims] 1. When carrying out construction work by dividing the required cross-section into small cross-sections in the earth and sand ground without cutting and widening it all at once, a handle is attached to the side of the can-shaped storage section whose upper part is the opening for material input, and a funnel-shaped bottom is installed. is bent so that its leading edge faces directly to the side, forming an injection nozzle. Immediately after this injection nozzle, the tip of the air tube faces with a gap around it, and this air tube is used to adjust the air pressure. A hand sprayer connected to an air hose through a valve is used to spray a thin layer of solidifying material such as mortar onto the face of the face to solidify the cross section, and then the process of excavation is repeated. A method for stabilizing the walls of earth and sand tunnels with a low degree of consolidation.