JPH0813997A - Tunnel construction method - Google Patents

Abstract

PURPOSE:To stabilize the natural ground over a long period, shorten the execution period, and reduce the execution cost. CONSTITUTION:The natural ground 1 is excavated, a lining 3 is formed on the exposed face 2a of the natural ground 1 by concrete spraying after the excavation, then boring is applied on the natural ground 1 from the lining surface 3a. Anchors 5 are inserted into holes to fix the natural ground 1, nearly flat plate-like blocks 4 superimposed on the lining surface 3a are coupled with the base ends of the anchors 5, and the blocks 4 are installed on the lining surface 3a. The natural ground 1 is stabilized, the work is simplified, the execution period is shortened, and the execution cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method.

[0002]

2. Description of the Related Art A tunneling method, for example, a mountain tunneling method which is carried out when the ground is hard, drills a hole for loading dynamite with a rock drilling machine driven by compressed air or hydraulic pressure. Blast with explosives such as. Blasted rocks, that is, shears, are carried out of the mines by a shearing machine, a truck, and the like. After carrying out the sludge, support work will be carried out to support the ground at the site where the blast was excavated. Digging while repeating such work. After that, it is done by covering the inside of the support work with lining concrete.

On the other hand, a tunnel construction method by NATM construction method for constructing shotcrete on the exposed ground surface immediately after excavation is performed. The outline of this Nathom method will be described with reference to FIG.

First, as shown in the sectional view of FIG. 4 (a), in the excavation process, the rock 11 is pierced by a rock drilling machine, and explosives are loaded into the hole to explode the rock, that is, the shattered rock. Is carried out of the mine.

Next, in the subsequent concrete spraying process, the exposed ground surface 1 of the excavation hole 12 excavated in the excavation process is performed.
2a is sprayed with concrete, and the lining 13 made of concrete supports the natural ground 11 with appropriate rigidity as shown in FIG. 4 (b).

The ground rock 11 and the lining 13 around the tunnel are integrated with each other in the subsequent lock bolt disposing process. FIG.
The arrangement of the lock bolts 14 shown in (c) is such that a plurality of holes are punched from the surface 13a of the lining 13 toward the natural rocks 11 by a drilling machine, and the lock bolts 14 are inserted into the respective holes, and the rock bolts 14 are grounded. 11 and the base end is engaged with the surface 13a of the lining 13 through an engaging device (not shown) to integrate the natural rock 11 and the lining 13, and in the finishing step, as shown in FIG.
As shown in (d), the surface 13a of the lining 13 and the base ends of the lock bolts 14 are covered with the lining concrete 15 by concrete spraying to improve the aesthetics, and drainage equipment and lighting for treating the spring water. Complete the tunnel by installing equipment such as ventilation and ventilation, and other auxiliary equipment.

[0007]

According to the above-mentioned NATO method, it is a rational method which does not require supporting work, allows proper deformation of the ground and allows the lining to balance with earth pressure. However, since the rock bolt is fixed to the ground and the base end is engaged with the surface of the lining to integrate the ground and the lining, the engagement between the base end of the lock bolt and the lining is extremely high. It is local, and it is difficult to obtain uniform lining and ground integration over the entire surface of the lining. Therefore, a gap is created between the lining and ground, which induces loosening of the ground. Sometimes. In addition, the work is troublesome because it requires a finishing process such as lining the surface of the lining and the base end of the rock bolt with lining concrete such as on-site casting or concrete spraying. There are problems such as increased costs.

Therefore, an object of the present invention is to make it possible to uniformly integrate the lining over the entire surface of the lining and to integrate the ground, thereby preventing loosening of the ground for a long period of time, shortening the construction period, and reducing the construction cost. It is intended to provide a tunnel construction method that can be expected to reduce construction costs and that can be constructed economically.

[0009]

[Means for Solving the Problems] The tunnel construction method of the present invention for achieving the above object is an excavation process for excavating a natural ground, and a concrete is exposed on the exposed surface of the natural rock after the excavation by exposing a natural rock. A concrete spraying process to form a lining on the surface and a hole is drilled from the lining surface toward the ground, an anchor is inserted into this hole to fix the anchor to the ground, and the base end of the anchor is the lining surface. And a block laying step of laying the block on the surface of the lining by engaging with a substantially flat plate-shaped block which is superposed on the block, and these steps are sequentially repeated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tunnel method according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is an explanatory view showing the outline of the present embodiment, and the reference numeral 1 in the drawing is a natural ground.

First, the tunnel construction planned portion of the natural ground 1 is shown in FIG.
In the excavation process, as shown in (a), a rock drilling machine driven by compressed air or hydraulic pressure is used to drill a hole for dynamite loading, and an explosive such as dynamite is charged into this hole. Blow up. The rock that has been shattered and turned into slip is carried out of the mine, and the slip is removed to form the excavation hole 2.

Next, spraying concrete is applied to the exposed rock surface 2a of the excavated hole 2 by the concrete spraying process, and as shown in FIG. 1 (b), the rock is exposed by the concrete lining 3. The surface 2a is covered and the ground 11
Is supported with appropriate rigidity.

Subsequently, in the block laying process, FIG.
As shown in (c), a plurality of blocks 4, 4, ... Are laid on the surface 3a of the lining 3, and auxiliary equipment and the like are installed as necessary to complete the tunnel.

The block laying process is shown in FIGS.
It will be described in detail with reference to FIG. 2, which is an enlarged view of the portion A of FIG.

Prior to the laying of the block 4, a hole is punched from the surface 3a of the lining 3 toward the natural ground 1 by a punching machine, and the hole (not shown) has a closed cross-sectional shape, for example, a deformed steel pipe. The anchor 5 configured by is inserted. After that, high-pressure water is injected into the anchor 5 to expand the anchor 5 so that the anchor 5 is brought into close contact with the inner peripheral surface of the hole to fix the anchor 5 to the ground.

Then, the surface of the lining 3 is formed with a through hole 4a or a plurality of through holes (not shown) for inserting an anchor, which is made of precast concrete and is formed at a substantially central portion of the block 4 on a substantially flat plate or at an arbitrary position. Insert the base end 5a of the anchor protruding from 3a to cover the contact surface 4c of the block 4 3
The block 5 is superposed on the surface 3a, and the block 4 is used as a reaction force to tension the anchor 5 to apply compressive stress to the lining 3 and the ground 1, and then the base end 5a of the anchor 5 is inserted into the through hole 4a of the block 4. The block 4 is fixed by engaging with the continuous engaging recess 4b by the engaging device 6.

If necessary, the engagement device 6 and the like are covered with an oil cap (not shown) filled with grease to prevent the base end 5a of the anchor 5 and the engagement device 6 and the like from being rusted, and to engage the recessed portion. The opening of 4b is closed with a lid (not shown). The operations from this perforation to the block fixing to the closing by the lid are sequentially performed, and the block 4 is laid on the surface 3a of the lining 3 as shown in FIG. A backfill material such as cement mortar is injected and filled into a gap (not shown) formed between the contact surface 4a of the block 4 and the surface 3a of the lining 3 by a backfill device or the like from the gap between the four.

In the block laying step, the anchor 5 having a closed cross-sectional shape is inserted into the hole drilled by the drilling machine, and the anchor 5 is expanded by injecting high-pressure water to fix the anchor 5 to the natural ground 1. PC steel wire instead of 5
Insert an anchor such as a PC steel rod into the hole and pressurize cement milk into the hole to fix the tip of the anchor to the ground 1,
It is also possible to apply tension to the anchor using a tension tool and fix the block 4 to the surface 3a of the lining 3 to give a large compressive stress to the lining 3 and the ground 1.

The block 4 is not limited to the prestressed concrete, but may be made of an appropriate material such as synthetic resin or metallic material. Further, the shape of the block is not limited to the quadrangular shape shown in FIG. 4, and it is also possible to use hexagonal shapes, triangular shapes, blocks having different dimensions, or blocks having different shapes in an appropriate combination.

In the above embodiments, the case where the present invention is applied to a mountain tunnel has been described, but for example, construction of a subway with a shallow installation depth provided under a street in an urban area or a tunnel tunnel with a small installation depth causes little overburden. It is also possible to apply to an open-cutting method widely used for parts.

More specifically, when excavating a groove from the ground, constructing a structure at the bottom of the excavation, and then backfilling to construct a tunnel, the exposed ground surface on both sides of the excavated excavation groove In the same manner as in the above embodiment, spray concrete is applied by the concrete spraying process, and the exposed surface of the natural rock is covered with the lining to support the natural rock with an appropriate rigidity.

Then, similarly to the block laying step in the above-mentioned embodiment, a hole is drilled from the surface of the lining toward the ground, an anchor is inserted into this hole to fix the anchor to the ground, and the base end of the anchor is covered. The block is laid on the lining surface by engaging with a substantially flat block that abuts on the work surface to form the side wall of the excavation trench.

According to the tunnel construction method of the present invention described above, after spraying concrete on the excavated ground exposed surface to cover the lining, the anchor is formed by piercing the ground from the lining surface. Inserted and fixed to the ground, and fixed to the ground so as to cover the lining surface by laying the block on the lining surface by engaging the base end of the anchor with the block that overlaps the lining surface The lining surface is covered by the block that is locked to the anchor, and the tension by the anchor acts uniformly over a wide range of the lining surface, and the lining and the ground and the block are integrated, There is very little loosening of the ground both during and after construction, the ground can be stabilized for a long period of time, and the lining is covered with blocks, which ensures the aesthetics of the tunnel. Cast-in-place or shotcrete The finishing process of the lining surface can be omitted, the work can be simplified, the construction period from excavation to block fixing can be shortened, and the block covering the lining surface can be manufactured in advance at the factory. Combined with this, it has the effect of being able to significantly reduce construction costs.

[0025]

Therefore, according to the tunnel construction method of the present invention described above, from the surface of the lining constructed on the excavated ground exposed surface to the base end of the anchor fixed to the natural ground on the lining surface. Since the block is laid on the lining surface by engaging the blocks that overlap with each other, the tension by the anchor acts uniformly over a wide range of the lining surface, and the lining and the ground and the block are integrated. Therefore, the looseness of the ground is suppressed during and after the construction, and the ground can be stabilized for a long period of time. Since the lining is covered with blocks to ensure aesthetics, it is possible to omit the finishing process of the lining surface such as casting on site or spraying concrete, shortening the construction period and significantly reducing the construction cost. Therefore, there are advantages peculiar to the present invention, such as being able to construct a tunnel while ensuring economic efficiency.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of an embodiment of a tunnel construction method of the present invention.

FIG. 2 is an enlarged explanatory view of a portion A in FIG.

FIG. 3 is likewise a schematic illustration of the present embodiment.

FIG. 4 is a schematic explanatory view showing an example of a conventional tunnel construction method.

[Explanation of symbols]

 1 Ground 2a Ground exposed surface 3 Lining 3a Lining surface 4 Block 4a Through hole 4b Engagement recess 5 Anchor 5a Base end

Claims (5)

[Claims] 1. An excavation step for excavating a rock mass, a concrete spraying step for forming a lining on the exposed rock surface by applying sprayed concrete to the exposed rock surface after excavation, and a lining surface On the lining surface, make a hole toward the ground and insert the anchor into this hole to fix the anchor to the ground and engage the base end of the anchor with a substantially flat block that overlaps the lining surface. And a block laying step of laying blocks on the tunnel. 2. An excavation step of excavating a rock mass, a concrete spraying step of applying spray concrete to the exposed rock surface after the excavation to form a lining on the exposed rock surface, and a lining surface On the lining surface, make a hole toward the ground and insert the anchor into this hole to fix the anchor to the ground and engage the base end of the anchor with a substantially flat block that overlaps the lining surface. And a block laying step of laying a block on the block, and the tunneling method is characterized in that the above steps are sequentially repeated. 3. The tunnel construction method according to claim 1, wherein the anchor having a closed cross-sectional shape inserted into the hole is inflated and brought into close contact with the hole to fix the anchor to the natural ground. 4. The tunnel construction method according to claim 1 or 2, wherein the tip of the anchor inserted into the hole is fixed to the ground to give tension to the anchor. 5. The engagement of the anchor base end with the block is performed by inserting the anchor base end into a through hole penetrating the block and engaging the base end of the anchor with an engagement recess continuous with the through hole. The tunnel construction method according to claim 1, which is performed.