JP4113187B2 - Construction method of underground structure - Google Patents

Description

  The present invention relates to a method for constructing a new underground structure above an existing hollow underground structure buried in the ground.

  In the basement, hollow underground structures such as tunnels, underground passages, and common grooves are embedded, but as shown in FIG. 1, for example, the existing tunnel 1 that is an existing hollow underground structure crosses the road to a close position. When constructing a new underground structure with a concrete box 2 in the form to be performed, or newly constructing an underground structure with a concrete box 2 in a form that crosses the railway near the upper position of the existing tunnel 1 as shown in FIG. There are things to build.

  As the construction method, the entire range of the newly installed concrete box is excavated by the open-cut method on the upper side of the hollow underground structure such as the existing tunnel 1, and the concrete box 2 is built in the opened part. It was. In the case of FIG. 1, for example, as shown in FIGS. 18 and 19, the upper side of the adjacent position of the existing tunnel 1 is excavated from the ground surface, and a new concrete box 2 is suspended and installed from the opening on the ground surface.

  Also in the case of FIG. 13, as shown in FIGS. 16 and 17, a shaft is constructed by excavating from the ground surface to the upper side of the adjacent position of the existing tunnel 1, and a new concrete box 2 is constructed from the opening on the surface. It is hung inside or manufactured and installed in a shaft. In the figure, 3 is a construction girder for supporting the railway, 8 is a foundation pile, and 4 is a temporary earth retaining pile.

  Since the load from above on the existing tunnel 1 is reduced by cutting to the position immediately above the existing tunnel 1 in this way, for example, a large buoyancy acts on the existing tunnel 1 in an area having groundwater, for example. As shown in FIGS. 16, 17, 18, and 19, the existing tunnel 1 is lifted and the surrounding ground is raised.

  Therefore, in order to prevent the existing hollow underground structure such as the existing tunnel 1 from rising, the problem can be solved by demolishing or removing the existing hollow underground structure for a period of time. In addition, a great influence such as the suspension of use of the existing hollow structure in the meantime occurs, and it is necessary to secure a site separately, and the cost is also required.

  In order to solve such a problem, various auxiliary methods for preventing the existing hollow structure from floating are proposed. FIG. 20 shows a first example of the auxiliary protection method, in which the ground anchor 5 is driven at the bottom of the existing tunnel 1, and the upper part of the existing tunnel 1 is cut to install the new concrete box 2, Thus, the ground anchor 5 can prevent the existing tunnel 1 from being lifted by buoyancy when the ground is released.

  FIG. 21 shows a second example of the auxiliary protection method, in which an anti-lifting material 6 such as a steel pipe roof is disposed horizontally on the upper part of the existing tunnel 1. In this case, the existing tunnel 1 is prevented from being lifted by covering the entire range of the range in which the lifting prevention material 6 is expected to be affected by the cutting, and covering this range. If necessary, the lift prevention material 6 can be further fixed to the ground by the grant anchor 5 to prevent the lift.

  FIG. 22 shows a method of laying a new concrete box 2 while preventing lifting. The upper part of the existing tunnel 1 is limited to a narrow area where there is no influence of lifting, and this area is cut by a cutting method. This is a construction method in which a shaft 7 is excavated and the concrete box 2 to be newly constructed is divided and constructed.

  In this method, the construction section is limited to a narrow area, a new underground structure is built, this area is built, backfilled, and after completion, the next construction section is built, and this is repeated in sequence. Thus, the entire structure is constructed, and the influence of excavation can be minimized throughout.

  The prior art is generally performed by those skilled in the art, and does not relate to a known literature invention.

  In the case of the construction method shown in FIGS. 20 to 21, it is not necessary to destroy the existing tunnel, but it is necessary to take auxiliary measures, which not only increases the cost, but also includes the construction method shown in FIG. 22. May become longer.

  The purpose of the present invention is to eliminate the inconvenience of the conventional example, and when a new underground structure is constructed near a hollow underground structure such as an existing tunnel or other underground structure, an auxiliary measure is required. However, it is possible to provide a construction method of an underground structure that can prevent an existing underground structure from rising at a low cost, does not prolong the construction period, and can be safely constructed.

  In order to achieve the above object, the present invention provides an underground structure construction method for constructing an underground structure at a position close to a direction perpendicular to the hollow underground structure above a hollow underground structure such as an existing tunnel. A start shaft and a reach shaft are built on both sides of the hollow underground structure, and at least above the existing hollow underground structure is at least high enough to prevent the hollow underground structure from rising due to buoyancy. Excavation of the earth and sand, moving the newly constructed underground structure horizontally from the start shaft to the arrival shaft, gradually removing the remaining earth and sand at the location, By installing this new underground structure above the existing hollow underground structure while replacing it with the earth and sand so that the necessary load is constantly applied, the existing soil and sand left above the existing hollow underground structure is installed. in That gradually replaced by underground construction which established the load required floating preventing buoyancy to underground structures it is an gist.

  According to the first aspect of the present invention, since excavation is not performed by the open-cut method, the earth and sand above the existing hollow underground structure is not excavated and replaced with earth and sand until just before the newly installed underground structure is installed. Since a newly installed underground structure is installed, a hollow underground structure such as an existing tunnel that is likely to generate buoyancy is not lifted by buoyancy until the newly installed underground structure is installed.

  In addition, since the start shaft and the reaching shaft are built on both sides of the existing underground structure, there is no possibility that these shafts will affect the existing hollow underground structure and cause buoyancy in the structure.

  And, since there is at least the earth and sand that is high enough to prevent the hollow underground structure from rising due to buoyancy until the newly installed underground structure is installed above the existing hollow underground structure, Lifting can be reliably prevented without taking any special measures to prevent lifting.

  As described above, the construction method of the underground structure of the present invention uses the existing hollow underground structure without using the open-cut method when constructing a newly installed underground structure near the upper position of a hollow underground structure such as an existing tunnel. Leave the earth above the structure, excavate the earth, replace the earth and sand, move the new underground structure from the start shaft to the destination shaft, and move the new underground structure above the existing hollow underground structure. Since the structure is installed, no auxiliary measures are required, the existing underground structure can be prevented from floating at low cost, the construction period is not prolonged, and it can be constructed safely. .

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an assumption diagram in the case where a new underground structure is constructed above an existing hollow underground structure by crossing the road, showing the first embodiment of the construction method of the underground structure of the present invention. A longitudinal front view and FIG. 3 are longitudinal side views of the same as shown in FIG. 1. As shown in FIG. 1, a concrete box 2 which is a newly installed underground structure is installed near the existing tunnel 1 as an existing underground underground structure. The construction method will be described with reference to FIGS.

  FIG. 4 shows a state before construction, and the existing tunnel 1 is buried in the underground ground of the road 16.

  From this state, as shown in FIG. 5, primary excavation is performed as a first step, and the board is lowered. As shown in FIG. 2, this excavates only a depth h1 from the road surface 16 so that earth and sand for a height h remain above the existing tunnel 1, and the height h is the buoyancy of the existing tunnel 1. It is the amount of earth and sand having a load sufficient to prevent the floating.

  Further, in this state, as a second step, temporary earth retaining piles 4 are placed at both sides of the existing tunnel 1 at a position where buoyancy does not act on the existing tunnel 1 as shown in FIG. A secondary excavation is performed between the earth retaining piles 4 and 4 to construct a start shaft 9 and an arrival resistance 10.

  At this time, the earth and sand for the height h are still left above the existing tunnel 1, and the existing tunnel 1 will not be lifted by buoyancy even if the starting shaft 9 and the reaching shaft 10 are built around. And the start stand 11 is built in the start shaft 9.

  Next, as shown in FIG. 6, as a third step, a bearing wall 12 as reaction force equipment is installed in the start shaft 9, and a concrete box 2 as a new underground structure is arranged, or this start The concrete box 2 is built in the shaft 9, and the blade edge 13 is assembled to the front part of the concrete box 2.

  And the propulsion equipment by the pushing jack 14 etc. is installed between the rear part of the concrete box 2 and the bearing wall 12.

  Next, as shown in FIG. 7, the concrete box 2 is propelled from the starting shaft 9 toward the reaching shaft 10 as a fourth step. This box propulsion work is to push the concrete box 2 up close to the existing tunnel 1 while excavating the face. By replacing the earth and sand with the concrete box 2, the load applied to the upper part of the existing tunnel 1 is increased. Do not reduce. In the figure, 15 indicates a strut.

  As a result, a constant load is always applied to the existing tunnel 1 from above, and the existing tunnel 1 will not be lifted by buoyancy even when excavating above the existing tunnel 1.

  In this way, the succeeding concrete box 2 is manufactured in the start shaft 9 behind the leading concrete box 2 as shown in FIG. 8, and connected to the leading concrete box 2 as shown in FIG. The subsequent concrete box 2 is further propelled while excavating the face.

  Then, as shown in FIG. 10, when the leading edge 13 of the concrete box 2 reaches the reaching shaft 10, the propulsion of the concrete box 2 is completed, and a newly installed concrete box is positioned near the existing tunnel 1. 2 is installed.

  Therefore, next, as shown in FIG. 11, the blade edge 13 is removed, and the propulsion equipment on the start shaft 9 side and the bearing wall 12 are removed. Then, as shown in FIG. 12, the approach portion 18 to the new concrete box 2 is excavated, and a new concrete box 2 is built here, and the upper part of the concrete box 2 is backfilled 19 to perform the construction. Complete.

  The first embodiment is a case where a new underground structure is constructed above an existing hollow underground structure by crossing the road 16, but the present invention is not limited to this, and FIG. A new underground structure may be constructed above the existing hollow underground structure by crossing the railway 17 as shown in FIGS. 13 to 15, and the construction method is the same as that of the first embodiment.

  Moreover, although the concrete box 2 was pushed out and propelled using the main pushing jack installed on the start shaft 9 side as a forward means of the new concrete box 2, the concrete box 2 is not limited to this. If it is a mechanism which can move horizontally, the new concrete box 2 can also be pulled and advanced from the reach shaft 10 side using the pulling equipment installed in the reach shaft 10 side.

  In the above, the case of a hollow underground structure such as an existing tunnel has been shown as the existing underground structure, but the present invention in the case of a building or other underground structure other than a hollow well can be similarly applied.

It is an assumption figure in the case of crossing the road which shows 1st Embodiment of the construction method of the underground structure of this invention, and constructing a newly installed underground structure above the existing hollow underground structure. It is a vertical front view same as the above which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view same as the above showing a first embodiment of a construction method for an underground structure of the present invention. It is a vertical side view of the state before construction which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 1st process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 2nd process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 3rd process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 4th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 5th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 6th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 7th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is a vertical side view of the 8th process which shows 1st Embodiment of the construction method of the underground structure of this invention. It is an assumption figure in the case of constructing a newly installed underground structure above an existing hollow underground structure by traversing the railway showing the second embodiment of the underground structure construction method of the present invention. It is a vertical front view same as the above which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is the same vertical vertical side view which shows 2nd Embodiment of the construction method of the underground structure of this invention. It is a vertical front view in the case of constructing a newly installed underground structure above an existing hollow underground structure by traversing a railway by a conventional open-cut method. It is a vertical side view in the case of constructing a new underground structure above an existing hollow underground structure by traversing a railway by a conventional open-cut method. It is a longitudinal cross-sectional front view in the case of constructing a newly installed underground structure above an existing hollow underground structure by crossing a road by a conventional open-cut method. It is a vertical side view in the case of constructing a new underground structure above an existing hollow underground structure by crossing a road by a conventional open-cut method. It is a vertical front view which shows the 1st example of the auxiliary construction method for the conventional lift prevention. It is a vertical side view which shows the 2nd example of the auxiliary construction method for the conventional lift prevention. It is a vertical front view which shows the conventional lifting prevention construction method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Existing tunnel 2 Concrete box 3 Construction girder 4 Temporary retaining pile 5 Ground anchor 6 Lift prevention material 7 Vertical shaft 8 Foundation pile 9 Starting shaft 10 Reaching shaft 11 Starting platform 12 Bearing wall 13 Cutting edge 14 Former push jack 15 Strut 16 Road 17 Railway 18 Approach section 19 Backfill

Claims (1)

In method for constructing underground structures to build underground structures in a direction of the proximity position that is perpendicular to the hollow underground structures above the existing hollow underground structures such as tunnels, on the side opposite sides of the existing hollow underground structures and construction of a starting pit and arrival pit, the hollow underground structures above the existing, excavated earth and sand, leaving the height of the sediment as possible to prevent the least the hollow underground construction floats by buoyancy, to new While moving the underground structure horizontally from the start shaft to the arrival shaft, remove the remaining sediment at the location gradually so that the necessary load is constantly applied to the existing hollow underground structure. the underground construction of new while replaced with sand by installing over the hollow underground structures of the existing, floating buoyancy to existing hollow underground construction according to sediment left in the hollow underground structures above the existing Prevention How to build the underground structure, characterized in that it go gradually replaced to load underground structure that established the necessary.

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