JP2007270502A - Upper part construction method and upper part construction structure in approach part of underpass tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a finish surface inexpensively without using different-shaped segments. <P>SOLUTION: This upper part construction structure 1 in the approach part 2A constructed by a shield tunneling method is constituted by placing concrete 4 up to height of the finish surface R from an upper end face 20a of the segment 20 when the upper end face 20a of the segment 20 in the approach part 2A is at a position being lower than the finish surface R forming an installation face of partitioning facility 3. A common segment piece 21 formed to have fixed height is arranged in an upper part of the segment 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an upper construction method and an upper construction structure in an approach portion of an underpass tunnel constructed by a shield construction method or the like.

Conventionally, underpass tunnels at three-dimensional intersections and the like have been constructed with vertical shafts on both sides of the tunnel portion, constructed between the compatible wells by a propulsion method, a shield method, and the like, and the approach portion is constructed by an open-cut method. In addition, earth retaining work such as pile driving is required in advance for excavation and excavation of shafts, and there are problems with the surrounding environment such as vibration and noise, and when performing these excavation work Since the construction occupation area on the road required for the placement and excavation of heavy machinery and shafts is wide, there is a problem that traffic obstacles occur at construction sites in urban areas. In addition, the construction period was long due to the vertical shaft.
In order to solve such a problem, for example, Patent Document 1 discloses a method of starting a shield excavator from the ground and continuously constructing all lines of the underpass tunnel.
Patent Document 1 assembles a segment having a rectangular section at the rear end of a shield excavator while excavating an underpass tunnel having a rectangular section by combining a plurality of shield excavators having a square section. In a section with a small earth covering such as an approach portion, a shield excavator disposed above among a plurality of shield excavators can be safely excavated by projecting in advance in the tunnel traveling direction. This eliminates the need for large shaft work and excavation work, thereby eliminating the above-mentioned problems in the surrounding environment and shortening the work period.
JP 2005-248546 A

However, according to the prior art, there are the following problems.
In the ground portion of the constructed approach section, partition equipment such as a railing or soundproofing equipment may be installed at the boundary between the tunnel forming the approach section and its surroundings. At that time, it was necessary to form the installation surface (finished surface) that forms the basis of the partition facility so as to be substantially parallel to the ground surface. Since the height of the segment of the approach section relative to the ground surface increases as the tunnel depth increases, in general, deformed concrete segments with different height dimensions for each segment ring are used. It is a construction method in which a finished surface that is arranged in the upper part and is substantially parallel to the above-described ground surface is formed. In order to manufacture such deformed segments with different heights for each segment ring, it is necessary to provide a formwork for each deformed segment or to modify the formwork. There was a problem of becoming.

  The present invention has been made in view of the above-described problems, and provides an upper construction method and a construction structure in an approach portion of an underpass tunnel that can construct a finished surface at a low cost without using a deformed segment. Objective.

In order to achieve the above object, the upper construction method in the approach part of the underpass tunnel according to the present invention is an approach of the underpass tunnel in which the upper part of the approach part where the segment is constructed is constructed so as to be a finished surface of a predetermined height. In the upper construction method in the section, when the upper end surface of the segment is lower than the finished surface, the concrete is cast from the upper end surface of the segment to the height of the finished surface.
In the upper construction structure in the approach portion of the underpass tunnel according to the present invention, the upper portion in the approach portion of the underpass tunnel constructed so that the upper portion of the approach portion in which the segment is constructed becomes a finished surface having a predetermined height. The construction structure is characterized in that concrete is cast from the upper end surface of the segment to the height of the finished surface.
According to the present invention, by placing concrete on the upper end surface of the segment of the approach portion, the upper portion of the approach portion can be formed on a finished surface having a predetermined height. This eliminates the need for installing different shaped segments having different heights for each segment ring as in the prior art. If the upper end surface of the segment is arranged below the finished surface, there may be a step in the concrete placement range, so there is no need to make the installation position of the upper end surface of the segment highly accurate. Construction can be simplified.

Moreover, in the upper construction method in the approach part of the underpass tunnel according to the present invention, the height between the segment and the finished surface is adjusted by placing a common segment piece formed at a certain height on the upper end surface of the segment. It is preferable.
According to the present invention, the height of the upper portion of the approach portion can be adjusted to be close to the finished surface by placing the common segment piece on the upper end surface of the segment.

Further, in the upper construction method in the approach part of the underpass tunnel according to the present invention, the upper construction method in the approach part of the underpass tunnel is constructed so that the upper part of the approach part where the segment is constructed becomes a finished surface having a predetermined height. However, when the upper end surface of the segment is at a position higher than the finished surface, the protruding portion of the segment that protrudes upward from the finished surface is removed.
According to the present invention, since the same segment can be installed in the entire underpass tunnel line, it is not necessary to manufacture a deformed segment for adjusting the height of the segment. For this reason, the formwork for manufacturing a deformed segment becomes unnecessary and manufacturing cost can be reduced.

In the upper construction structure in the approach portion of the underpass tunnel according to the present invention, the upper portion in the approach portion of the underpass tunnel constructed so that the upper portion of the approach portion in which the segment is constructed becomes a finished surface having a predetermined height. A construction structure is characterized in that a deformed steel segment having a different height dimension is placed on the upper end surface of the segment, and concrete is placed in a space inside the steel segment.
According to the present invention, an irregular steel segment having a different height dimension is placed on the upper end surface of the segment of the approach portion for each segment ring, and the upper end surface of the steel segment is adjusted to be a finished surface. Can do. Since a conventional deformed segment made of concrete is unnecessary, a concrete formwork for constructing the finished surface R is not necessary, and the manufacturing cost can be reduced.

  According to the upper construction method and the upper construction structure of the approach part in the underpass tunnel of the present invention, the upper part of the approach part is predetermined without installing various deformed segments having different height dimensions for each segment ring as in the prior art. It can be constructed to have a height of the finished surface. Since the deformed segment is unnecessary, it is possible to reduce the manufacturing cost related to the production or modification of the mold at the time of manufacturing the deformed segment.

Hereinafter, the upper construction method and the upper construction structure of the approach portion in the underpass tunnel according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
1 is a side view showing an upper construction structure of an approach portion according to the first embodiment of the present invention, FIG. 2 is an overall side view showing an underpass tunnel, and FIG. 3 is a segment A- in the approach portion shown in FIG. It is A sectional view.

  As shown in FIG. 1, the upper construction structure 1 of the approach portion 2A according to the first embodiment is a three-dimensional intersection composed of shield tunnels constructed by rectangular segments extending in a natural ground by a shield method. This is applied to the approach portion 2A of the underpass tunnel 2 of, for example, a surface substantially parallel to the ground surface G (finished surface R) is formed as an installation surface for installing the partition equipment 3 such as a soundproof wall or a railing. Has been built. In the first embodiment, the finished surface R is located above the ground surface G.

First, the underpass tunnel 2 and the approach portion 2A to which the upper construction structure 1 is applied will be described.
As shown in FIG. 2, the underpass tunnel 2 is constructed in a substantially U shape in a side view, and is connected to a tunnel portion 2B extending in the ground from the ground surface G to the tunnel portion 2B. The approach portion 2A is open at the top. In other words, a slope that gradually increases in depth from the ground toward the ground is formed, becomes a substantially horizontal direction at a predetermined depth, and further, an upward slope is formed at a predetermined position toward the ground. Yes.

As shown in FIG. 2, the shield method employed in the construction of the underpass tunnel 2 can employ various well-known methods, but in the first embodiment, the rectangular cross section is advantageous from the advantage of effective use of the cross section. A shield machine (not shown) is used, and a concrete segment is assembled behind this rectangular shield excavator.
In addition, this rectangular shield excavator can excavate by making each excavation cross section small, for example by dividing | segmenting a cutter into plurality. Then, by leading the upper cutter before the lower cutter, the approach portion 2A with a small earth covering can stably excavate the natural ground.

  As shown in FIG. 1, a segment 20 (described as “segment ring 20” if necessary) constructed continuously in the tunnel axis direction on the approach portion 2A is formed by connecting individual segment pieces in the circumferential direction. It is comprised and has comprised the substantially U shape by the cross sectional view which open | released the upper end. That is, the segment ring 20 includes side portions 20b and 20b and a bottom portion 20c. And the upper end surface 20a of the segment ring 20 is constructed so as to be substantially flush with the ground surface G, for example. Therefore, the height dimension of the side part 20b (refer FIG. 3) of the segment ring 20 becomes large as the depth of a tunnel increases.

Moreover, the common segment piece 21 formed in the fixed height dimension by the upper part of the both sides 20b and 20b is arrange | positioned at the segment 20. As shown in FIG. As shown in FIG. 1, the upper end surface 21a of the common segment piece 21 is formed with an inclined surface having substantially the same angle as the inclined angle in the tunnel axis direction of the approach portion 2A in a side view. The segment 20 of the approach portion 2A uses a segment piece in which a part of the side portion 20b and the bottom portion 20c thereof are used in the tunnel portion 2B, but the common segment piece 21 described above is placed on the segment 20 and arranged. Thus, the height of the upper portion of the approach portion 2A is adjusted so as to approach the finished surface R.
The common segment piece 21 does not need to be installed over the entire range of the approach portion 2A. For example, as shown in FIG. 1, the shallow portion of the tunnel portion in the approach portion 2A (the side where the height dimension of the segment 20 is small) is common. When the segment piece 21 is disposed, the common segment piece 21 is not installed because the segment piece 21 protrudes upward from the finished surface R.
The approach portion 2A has an upper end surface 21a of the common segment piece 21 and an upper end surface 20a of the segment 20, but the upper end surface 21a of the common segment piece is also “ This will be described below as “end face 20a”.

As shown in FIG. 1, in a state where the segment 20 and the common segment piece 21 configured as described above are installed in the approach portion 2A, a step is formed in the tunnel axis direction on the approach portion 2A. The step at this time is arranged at a position below the finished surface R.
Then, as shown in FIG. 3, the concrete 4 is placed from the upper end surface 20 a of the segment 20 to the height of the finished surface R. The placing method at this time is to install the mold 5 on the upper end surface 20 a of the segment 20 and fill the concrete 5 inside the mold 5. In addition, it is preferable to arrange | position a reinforcing bar and an anchor reinforcement (illustration omitted) in the mold 5 as needed.
In this way, if the upper end surface 20a of the segment 20 is disposed below the finished surface R, there may be a step or the like within the placement range of the concrete 4, so the installation position of the upper end surface 20a of the segment 20 Can be constructed with high accuracy, and the construction can be simplified.
Thus, the upper construction structure 1 of the approach part 2A is constructed, and the partition facility 3 can be installed on the finished surface R formed.

  As described above, in the upper part construction method and the upper construction structure of the approach part in the underpass tunnel according to the first embodiment, the approach part is not provided for each segment ring without different shaped segments having different height dimensions as in the prior art. The upper part of 2A can be constructed so as to have a predetermined finished surface R height. Since the deformed segment is unnecessary, it is possible to reduce the manufacturing cost related to the production or modification of the mold at the time of manufacturing the deformed segment.

Next, embodiments of the second and third embodiments of the present invention will be described with reference to FIGS. 4 and 5, but the same or similar members and parts as those of the first embodiment described above are the same. Description is abbreviate | omitted using the code | symbol of, and a different structure from 1st embodiment is demonstrated.
FIG. 4 is a side view showing the upper construction structure of the approach portion according to the second embodiment.
As shown in FIG. 4, in the second embodiment, in the approach portion 2A, a segment 22 having a rectangular section is installed in the same manner as the tunnel portion 2B, and protrudes upward from a predetermined finished surface R. The part (referred to as the projecting part 22a) is removed by a cutting means (not shown) such as a concrete cutter or a wire saw to form a finished surface R.
In the case of the second embodiment, since the same segment as the tunnel portion 2B can be installed in the entire underpass tunnel 2 line, it is not necessary to manufacture a deformed segment as in the prior art. Accordingly, a mold for manufacturing the deformed segment is not necessary, and the cost can be reduced.

Next, FIG. 5 is a front sectional view showing the upper construction structure of the approach portion according to the third embodiment.
As shown in FIG. 5, in the third embodiment, a deformed steel segment 6 having a different height dimension for each segment ring 20 is placed on the upper end surface 20 a of the segment 20 of the approach portion 2 </ b> A. The upper end surface 6a of the manufactured segment 6 is adjusted to be a finished surface R. The steel segment 6 has a shape in which the upper end surface 6a is inclined at a predetermined angle with respect to the lower end surface 6b. And the steel segment 6 comprises the outer shell body by which the inner peripheral side opened when installed, and the space 6c is formed in the inside enclosed by the outer shell body. The upper construction structure 1 is configured such that the steel segment 6 is installed on the upper end surface 20 a of the segment 20, and the concrete 7 is placed in the space 6 c of the steel segment 6.
In the third embodiment, the steel segments 6 are manufactured in different sizes for each segment ring, and concrete placement is performed on the plurality of steel segments 6 at a time after installation on the site. it can. And since the concrete formwork for constructing the finishing surface R becomes unnecessary, manufacturing cost can be reduced.

The first to third embodiments of the upper construction method and the upper construction structure in the approach portion of the underpass tunnel according to the present invention have been described above, but the present invention is limited to the first to third embodiments. However, the present invention can be changed as appropriate without departing from the spirit of the invention.
For example, in the first to third embodiments, the position of the upper end surface 20a of the segment 20 of the approach portion 2A is lower than the finished surface R in the first embodiment, and the finished surface in the second embodiment. Although it is above R, it is not limited to either one below or above, and the above-described upper and lower positions may be mixed in one approach portion 2A. That is, in the portion below the finished surface R, the common segment piece 21 is disposed on the upper end surface 20a of the segment 20 as necessary, and the concrete 4 is placed from the upper end surface 21a to the finished surface R. Moreover, what is necessary is just to remove this protrusion part 22a with a cutting | disconnection means in the part with the protrusion part 22a which the segment 20 protruded upwards from the finishing surface.
Moreover, in 1st Embodiment, although the common segment piece 21 is provided, it is not necessarily limited to installing this. It is preferable to install according to the height dimension of the segment 20 of the approach portion 2A and the position of the finished surface. And the height dimension of the common segment piece 21 can be set to the height dimension suitable for construction conditions.

It is a side view which shows the upper structure of the approach part by 1st embodiment of this invention. It is a whole side view showing an underpass tunnel. It is the sectional view on the AA line of the segment in the approach part shown in FIG. It is a side view which shows the upper construction structure of the approach part by 2nd embodiment. It is sectional drawing which shows the upper structure of the approach part by 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Superstructure 2 Underpass tunnel 2A Approach part 3 Partitioning equipment 4, 7 Concrete 6 Steel segment 20 Segment 20a Upper end surface 21 Common segment piece R Finish surface G Ground surface

Claims (5)

The upper construction method in the approach part of the underpass tunnel that constructs the upper part of the approach part where the segment is constructed so as to be a finished surface of a predetermined height,
In the approach portion of the underpass tunnel, the concrete is placed from the upper end surface of the segment to the height of the finished surface when the upper end surface of the segment is at a position lower than the finished surface. Upper construction method.   The common segment piece formed in a fixed height dimension is placed on the upper end surface of the segment to adjust the height between the segment and the finished surface. Upper construction method in approach part of underpass tunnel. The upper construction method in the approach part of the underpass tunnel that constructs the upper part of the approach part where the segment is constructed so as to be a finished surface of a predetermined height,
The upper construction method in the approach part of the underpass tunnel, characterized in that when the upper end surface of the segment is at a position higher than the finished surface, the protruding part of the segment protruding upward from the finished surface is removed. . The upper construction structure in the approach part of the underpass tunnel constructed so that the upper part of the approach part in which the segment is constructed becomes a finished surface of a predetermined height,
An upper construction structure in an approach portion of an underpass tunnel, wherein concrete is cast from an upper end surface of the segment to a height of the finished surface. The upper construction structure in the approach part of the underpass tunnel constructed so that the upper part of the approach part in which the segment is constructed becomes a finished surface of a predetermined height,
An underpass tunnel approach characterized in that it is constructed by placing a deformed steel segment having a different height dimension on the upper end surface of the segment and placing concrete in the space inside the steel segment. Superstructure in the department.

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