JP4761052B2 - Precast box culvert excavation method without margin - Google Patents

Description

  In the present invention, when a precast box culvert made of reinforced concrete is constructed by the open-cut method in the basement, a temporary earth retaining wall and a precast box culvert are pressed by press-fitting a combination panel (side wall precast concrete panel + steel bark steel panel + temporary material). An earth retaining excavation method laying precast box culvert made of reinforced concrete, which can be constructed without margin.

The process for constructing a precast box culvert made of reinforced concrete under the road and river using the conventional earth retaining method is as follows.
1. The excavation groove width is set up with a retaining wall necessary for laying the box culvert.
2. Drill beam holder.
3. Box culvert is introduced.
4). Laying box culvert.
5. Backfill.
6). Cut the beam.
7). Pulling out the retaining wall

Reference 1

Reinforced concrete precast box culvert road burial guidelines Author National Box Culvert Association Editor National Land Development Technology Research Center

Reference 2

Road earthwork-Temporary structure guideline editor Japan Road Association
Japanese Patent Application No. 2003-287646 (P2003-287646) Japanese Patent Application No. 2003-367202 (P2003-367202)

  When building a precast box culvert made of reinforced concrete in the basement by the conventional open-cut method, the excavation groove width takes the margin width 1 necessary for the laying work of the box culvert 3 and places the retaining wall. In narrow roads, rivers where private houses are adjacent, etc., there are places where it is difficult to secure a width for placing the retaining wall with a margin required for this laying work, and construction becomes difficult. Therefore, by integrating the function of the retaining wall and the function of the side wall portion of the box culvert 3, it is not necessary to take a margin width and an attempt is made to solve the above-mentioned problem.

  When the temporary earth retaining wall 2A is driven as shown in FIG. 1, the temporary earth retaining wall 2A is generally pulled out and is not in the ground. However, when this is pulled out, the earth and sand adhere to the temporary retaining wall, which is also pulled out, sinking the surrounding ground, tilting the private house, cracking the wall, cracking the dirt and bath tiles. It causes social problems such as entering. Therefore, by integrating the function of the retaining wall 2A and the function of the side wall portion of the box culvert 3, the influence of settlement is minimized by removing the temporary material only for the covering portion where the box culvert is necessary for the function. It has been devised to keep it down.

  The present invention is intended to solve the problems of such a conventional configuration, and when laying the box culvert 3 in the excavation groove, the margin width 1 with the retaining wall necessary for the work is not taken. The purpose is to reduce ground subsidence when the long retaining wall 2A is pulled out.

  In order to achieve the above object, the present invention provides a combination panel in which a side wall portion of a precast box culvert made of reinforced concrete, a steel panel for bark, and a temporary material are integrated into a hard ground directly on a soft ground. On the other hand, the side wall serves as both a permanent structure and a temporary earth retaining wall by pressing into a predetermined position directly or using an auxiliary method (auger combined use, water jet combined use). It is not necessary to take the margin necessary for laying the culvert.

  In addition, the press-in of the combination panel eliminates the need to pull out the long temporary retaining wall used in the usual open-cut method after laying the box culvert. For the purpose of not loosening the ground on the private side, with the temporary material fixed, pull out the steel panel for the last part corresponding to the earth covering, and the temporary material should be in a stable state after the completion of backfilling. By removing it, it is a construction method that limits the pullout of the retaining wall to only the covering part.

  As means for solving the above problems, the steel panel for bark can be integrated with the side wall precast concrete panel, the reaction force can be removed from the previous press-fitting panel when the next combination panel is press-fitted, and the removal operation can be performed at the top of the combination panel. The above problem can be solved by providing a high-strength bolt that satisfies the conditions such as being able to be used in the steel panel for the last time.

In addition, for the purpose of not loosening the ground on the private side, the action of pulling out the steel panel for the bark at the part corresponding to the earth covering with the temporary material fixed is the side wall part of the precast box culvert made of reinforced concrete, By tightening the temporary material with bolts, the temporary material is not lifted when the steel panel is pulled out, and the earth is retained using the temporary material for the purpose of not loosening the ground on the private side.
Temporary materials shall be temporary materials that can resist earth pressure depending on the depth of the covering.

  As described above, the earth retaining method according to the present invention does not require a margin for laying the temporary retaining wall and the box culvert when the reinforced concrete precast box culvert is laid by the opening method.

  In addition, the long temporary retaining wall used in the ordinary earth excavation method does not have to be pulled out after laying the box culvert, and the subsidence to the surrounding area is reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 shows a general diagram of the standard soil excavation method and is shown for comparison with the present invention.

  In the figure, FIG. 1 shows a general diagram of standard earth retaining excavation method, 1 is a marginal space between a temporary retaining wall and a precast box culvert, 2A is a temporary retaining wall, and 3 is a precast box culvert. . This construction method was devised for the purpose of reducing this margin width to zero and reducing the temporary retaining wall to the minimum length, which corresponds to the cover of the box culvert. Embodiments and enforcement steps will be described below with reference to the drawings.

  Fig. 2 shows a general diagram of the implementation of this method. Reference numeral 2 is a temporary material, and 4 is a box culvert for this method.

  FIG. 3 shows the configuration of the combination panel. In the configuration of this combination panel, the steel panel 5 for final use and the side wall precast concrete panel 6 are fastened with a high tension bolt 8, and the temporary material 2 and the side wall precast concrete panel 6 are connected with a bolt 7.

  FIG. 4 shows the structure of a steel panel for bark. Finally, the steel panel 5 has a structure that can withstand the pressure when the combined panel is press-fitted, and a long nut 10 is fixed on the side of the precast concrete panel so that it can act as a reaction wall when the next combined panel is pressed-in. Then, high tension bolts 8 are installed on the steel panel side for the last, and both panels are fixed by the fixing plate 9. Below, the construction method of this construction method will be described with reference to the drawings.

  In FIG. 5, the combination panel is pressed into a predetermined underground position directly on the soft ground, directly on the hard ground, or using an auxiliary method (auger combined use, water jet combined use).

  FIG. 6 shows the steel panel 5 for the last use, which is no longer acting as a reaction wall when press-fitting the combination panel, with the temporary material 2 kept in close contact with the ground and the high tension bolt 8 removed. The steel panel 5 is pulled out. At this time, the temporary material 2 is left for the purpose of retaining the ground on the private side, and the retaining beam 11 is installed to hold the mountain.

  FIG. 7 shows a state in which the steel panel 5 for bark has been removed and backfilled 11.

  FIG. 8 shows a state where excavation is carried out, a cut beam and an upset 13 are installed, and a foundation work 14 is applied as flooring.

  In FIG. 9, an in-situ reinforced concrete bottom slab 16 is placed on the foundation work 14 and integrated with the side wall precast concrete panel 6. Next, the top plate precast concrete panel 15 is installed and tightly connected to the side wall precast concrete panel 6.

  In FIG. 10, the box culvert 4 for the construction method is completely buried to a predetermined depth by backfilling and removing the temporary material. As described above, according to this embodiment, the marginless width precast box culvert cutting method can be applied.

General drawing of standard cutting method General diagram of the implementation of this construction method (non-earth retaining method) Configuration diagram of combination panel Structural diagram of steel panel for bark Press-fit combination panel underground State drawing of steel panel for pulling out from combination panel Final drawing of steel panel drawing trace backfill Drilling and beam drawing Site placement of reinforced concrete bottom slab and installation of top slab precast concrete panel Backfill, remove temporary material, complete box culvert for this method

Explanation of symbols

1 Temporary earth retaining wall and precast box culvert margin 2A Temporary earth retaining wall 2 Temporary material 3 Precast box culvert 4 Box culvert for this method 5 Ladder steel panel 6 Side wall precast concrete panel 7 Bolt 8 High tension bolt 9 Fixing plate 10 Long nut 11 Retaining beam 12 Bare steel panel removal trace backfill 13 Cut beam, uplift 14 Foundation work 15 Top plate precast concrete panel 16 On-site reinforced concrete bottom plate 17 Backfill

Claims (1)

When building a precast box culvert made of reinforced concrete in the basement by the earth retaining method, it is constructed by the following process.
1. Press-fit a combination panel (side-wall precast concrete panel + steel panel for larva + temporary material).
2. Pull out the steel panel for the last part corresponding to the earth covering, leaving the temporary material.
3. Drilling beam put.
4). Placing reinforced concrete on site at the bottom.
5. Install the top plate precast concrete panel.
6). Backfill.
7). Pull out the temporary material.
Precast box culvert excavation method with no margin in the excavation method to construct reinforced concrete precast box culvert.

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