JPS6117696A - Construction of underground head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a construction method for underground shafts such as tunnels, and is particularly suitable for constructing underground shafts for subways, public ditches, etc. constructed in urban areas. Concerning construction methods for underground tunnels using underground walls.

(Prior art and problems) Generally speaking, the method of constructing underground tunnels is the cut-and-cover method from the ground surface for relatively shallow locations, and the shield method for deeper locations, each of which has the following problems.

First of all, with the open cut method, all construction work is done from the ground.
For example, when constructing an underground tunnel under a road, general lining,
Construction will be carried out vertically through the processes of excavation, tunnel construction, and backfilling.

For this reason, the above ground will be used for a long period of time during the construction period, causing a great deal of inconvenience to traffic and the surrounding area.

On the other hand, the shield construction method uses vertical shafts excavated at appropriate locations as bases and constructs horizontally underground, so compared to the open-cut construction method, the area used above ground is smaller, and the degree of confusion about traffic and the surrounding area is lower.

However, it takes a long time to prepare, the equipment is expensive, and since the construction is mostly underground, it usually requires an auxiliary construction method for underground water, which increases costs.

Incidentally, as a recent trend, underground tunnels being constructed in the suburbs of cities are being constructed deeper and deeper, and the shield method is mainly used. In many cases, we have no choice but to
In this case, it is necessary to excavate to a considerably deep position.

Most of the earth and sand created by this excavation has to be backfilled again, which poses the problem of deteriorating the economic efficiency of the open-cut construction method.

(Purpose of the Invention) This invention has been made in view of the above-mentioned conventional problems, and it is possible to significantly reduce the inconvenience to residents in the vicinity of traffic 2 by reducing the area used on the ground during the construction period, Another object of the present invention is to provide a method for constructing an underground tunnel that enables construction of an underground tunnel without using an auxiliary construction method for water stoppage and is highly economically effective.

(Structure of the Invention) In order to achieve the above object, the present invention uses a method for constructing an underground tunnel, in which a continuous underground wall having approximately the same width as the underground tunnel to be constructed is formed with only a portion corresponding to the side wall of the tunnel as a concrete wall. step, forming a shaft between the underground walls or at an appropriate location, excavating from the shaft along the longitudinal direction of the underground wall, and sequentially locking arch-shaped supports to the upper end of the concrete wall; It is characterized by consisting of a process of forming a main shaft.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 show an embodiment of the method for constructing an underground tunnel according to the present invention.

In the construction method shown in the figure, first, as shown in Figure 1,
A continuous underground wall 10 having substantially the same width as the underground tunnel to be constructed and having a planar rectangular shape with both ends closed is formed.

The underground wall 10 is formed by, for example, a mud excavation method, and the reinforcing bar cage 12 is placed at a predetermined height from the bottom end of the excavated vertical trench, specifically, to a height corresponding to the side wall of the underground tunnel to be constructed. Concrete 1 by pouring the construction concrete
14, and above it is a special grout (S, G) wall 16 in which a self-hardening stabilizing liquid is injected and hardened.

It is preferable that the joints between the concrete wall 14 and S and G 116 be constructed as shown in detail in FIG. 1(C).

That is, a steel plate 18 having a substantially S-shaped cross section is fixed to the upper end of the reinforcing bar strip 12 so that its bent end 18 a slightly protrudes inside the reinforcing bar cage 12 , and the recess 1 of the steel material 18 is fixed.
A filler material 20 having a square cross section (specifically, any material that can prevent concrete from adhering to the filler material 20, such as foamed polystyrene) is stored and buried in the filler material 8b, and then concrete is poured.

The concrete pouring surface extends approximately up to the upper end surface of the steel plate 18, and the S and G walls 16 are formed above it. When the construction is performed in this manner, when the filler 20 is removed when forming the main shaft as described later, the recess 1 of the steel plate 18 will be removed.
8b is suitable for locking the end of the shoring, and the bent end 18a serves as a guide when erecting the reinforcing bar 12, and when concrete is poured in muddy water, the upper end part is free from defects. There is a risk that this will become a steel plate 18.
It can be reinforced with.

Note that the outer edge of the concrete wall 14 and the recess 1 of the steel plate 18
8b (W>) is set to a distance that allows insertion of a tremie pipe for pouring concrete.

Moreover, the concrete wall 74 of the underground wall 10 is not formed in accordance with the construction status of the adjacent construction area on the front and rear gable sides 10a and 10b, and has a total length of S.

G! X! You can close it.

The shaft 22 is formed after the formation of the underground wall 10 has been completed or has progressed to a certain extent.

The vertical shaft 22 is constructed by forming a concrete wall 24 between the underground walls 10 so as to form a substantially rectangular shape at the front end 10a of the underground wall 10, and installing a strut 26 inside the shaft to form an underground tunnel. Excavate to the formation depth and form bottom slab 2.8.

In this case, the entire length of the wall body 24 may be formed as an underground wall in advance when the underground wall 10 is formed.

Thereafter, as shown in FIG. 3, excavation is performed along the longitudinal direction of the underground wall 10 to form the main shaft 30. At this time, a predetermined range ( After injecting reinforcing chemical grout into the hatched areas in FIGS. 2(a) and 2(b), the portion of the wall 24 where the main shaft 30 will be formed is demolished.

The formation of the main pit 30 is performed in the following steps.

First, excavate in the shape of an underground tunnel, and
After taking out the filler material 20 exposed on the inner surface of the steel plate 18 and fixing both ends of the arch-shaped support 34 in the recess 18b of the steel plate 18, the support 34 and the concrete W14 are removed.
A secondary lining 40 is performed by pouring concrete along the inner surface of the secondary lining I40, and an invert 42 is formed to connect both ends of the secondary lining I40.

Then, by repeating the above-described procedure, the main shaft 30 is formed up to the gable side 10b of the underground wall 10.

Now, constructing an underground tunnel using the method described above has the following advantages.

(a) The earth expansion work is limited to the underground wall 10 and the vertical shaft 22, and it is possible to significantly reduce the sense of confusion for traffic and roadside residents.

(b) Lining the road surface and excavating the upper part as in the open-cut method.

Construction such as backfilling is not required.

(c) Since the underground wall 10 shuts off water around the underground tunnel, auxiliary construction methods for dealing with groundwater are not required.

(d) Since the concrete wall 14 of the underground wall 10 opposes the tonosho via the arch-shaped support 34, subsidence of the ground can be prevented, and even if subsidence occurs, it will not spread to the outside of the underground wall 10. There's nothing to do.

(E) Since the underground wall 10 serves as a guide when forming the main shaft 30, construction errors in the underground tunnel are reduced and accuracy is improved.

(f) Compared to the open-cut method, it has the effect of (b), so it is superior in shortening the construction period and being economical. It also eliminates the need for expensive equipment like the shield construction method, making it cheaper and shortening the construction period.

(g) The S and G walls 16 above the underground wall 10 do not need to be removed unlike concrete walls.

FIG. 4 shows a second embodiment of the invention,
The characteristic point is that the concrete M114 of the above-mentioned underground wall 10
, pre-formed precast concrete (P, C)
It is located where it is formed by the plate 44.

Even if the P and C plates 44 are used, the same effects as in the above embodiment can be obtained, and they can be constructed more easily than cast-in-place concrete, and since concrete is not poured using tremie pipes, the above-mentioned There is also the advantage that there is no need to consider the interval (W) as in the embodiments, and the walls and thickness can be made thinner.

FIG. 5 shows a third embodiment of the present invention, the features of which are as follows.

That is, in this embodiment, the vertical shaft 22 is connected to the underground wall 10.
It is not provided inside the wall, but is formed in a location close to this, and this and the inside of the underground wall 10 are connected through a horizontal shaft 46.

This embodiment has the advantage that the shaft 22 can be formed at any location depending on the surrounding situation.

Figures 6 to 8 show other embodiments of the method for forming the main shaft 30, in which Figure 6 is applied to free-standing strata, and Figure M7 is applied to relatively unstable geology. Suitable for the 8th
The figure shows a construction method suitable for non-self-supporting geology.

In the fourth embodiment shown in FIG. 6, the main shaft 30 is constructed by first excavating the upper half 50 in a ring shape, erecting an arch-shaped support 34 in the same manner as in the first embodiment, and then ．． Lower half 54
The secondary lining 40 is applied by excavating in this order, and then the invert 42 is formed.

In the fifth embodiment shown in FIG. 7, the so-called Metsu cell construction method is applied. First, an arch-shaped Metsu cell 56 is propelled, the upper half 50 is excavated in a ring shape, and the support I34 is constructed. After placing temporary rolling concrete on the inner surface of the shoring 34 as necessary, the core portion 52. The lower half 54 is excavated and the secondary surface ■40. The invert 42 is formed in this order.

Furthermore, in the sixth embodiment shown in FIG. 8, a so-called roof shield construction method is applied, and a semicircular shield excavator 58 is used to propel the excavator, and an arch-shaped segment 60 is After assembling and injecting backfill in the same manner as lining 34, the lower half 54 is excavated, and the secondary lining 40. Construct in the order of invert 42.

In addition, although the case where the underground tunnel is constructed in one stage was illustrated in the above embodiment, it may be formed in a plurality of stages in a multi-stage shape.

(Effects of the Invention) As explained in detail in the embodiments above, the underground tunnel construction method according to the present invention combines the advantages of the conventional open-cut construction method and the shield construction method, so that the surface area used above ground is reduced. It is small and eliminates the need for auxiliary construction methods to stop water, which has an extremely large economic effect, and various excellent effects can be obtained, such as the ability to apply various construction methods depending on the geology for forming the main shaft.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams showing one embodiment of the present invention in the order of steps, Figure 4 is a sectional view showing another embodiment of the concrete wall, and Figure 5 shows another method of forming a shaft. The explanatory drawings and FIGS. 6 to 8 are sectional views of main parts showing other methods of forming the main shaft. 10...Underground wall 12...Reinforced steel 14...Concrete wall 16...
S, G wall 18...Steel plate 20...
... Filling material 22 ... Vertical shaft 24 ...
...Wall body 26...Cut beam 28...
... Bottom plate 30 ... Book pit 34.
...Shoring 40...Secondary lining 42
...Invert 44...P, C board
46...Horizontal Pit 50...Upper half
52...Core part 54...Lower half part
56...Metsucell 58...Shield excavator 60...Segment patent applicant
Obayashi Co., Ltd. Composition Rihito
Patent Attorney - Kensuke Shiro faI diagram UD (b) Figure 2 (b) Figure 3

Claims (4)

[Claims] (1) A process of forming a continuous underground wall having approximately the same width as the underground tunnel to be constructed, with only the portion corresponding to the side wall of the tunnel as a concrete wall, a process of forming a shaft between the underground walls or at an appropriate location, the shaft 1. A method for constructing an underground tunnel, comprising the steps of: excavating along the longitudinal direction of the underground wall; and sequentially locking arch-shaped supports to the upper end of the concrete wall to form a main shaft. (2) The method for constructing an underground tunnel according to claim 1, wherein the concrete wall is made of cast-in-place concrete. (3) The method for constructing an underground tunnel according to claim 1, wherein the concrete wall is made of a precast concrete plate formed in advance. (4) In the concrete wall, a steel plate bent into a substantially S-shape is placed near the upper end of the concrete wall, and filler is stored and buried in the bent portion of the steel plate, and the filler is filled after excavating the main shaft. 4. The method for constructing an underground tunnel according to claim 2 or 3, characterized in that the shoring is locked in the recessed portion of the steel plate.