Deck slab retaining structure and retaining method

Abstract

To provide a deck slab retaining structure and retaining method capable of retaining a deck slab without using under-ground piled columns or intermediate piles.SOLUTION: A structure 10, which holds a deck 14 erected between opposing retaining walls 12 to the retaining walls 12, comprises a first connecting member 16 that protrudes laterally from the retaining wall 12 and is connected to a side end portion 32 of the deck 14 to hold the deck 14 to the retaining wall 12, and a second connecting member 18 that is connected from the retaining wall 12 diagonally above the deck 14 to an upper portion 34 of the deck 14 to hold the deck 14 to the retaining wall 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a retaining structure and a retaining method for a deck slab, such as a reverse-wound slab, constructed using a reverse-wound construction method. [Background technology]

[0002] Conventionally, as a method for constructing underground structures, a reverse-rolling construction method has been known in which excavation and construction of the framework are alternately repeated from above. In this reverse-rolling construction method, the reverse-rolling slab is generally held in place by integrating structural columns and intermediate piles driven into the ground with the reverse-rolling slab (floor slab) (see, for example, Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-223084 A [Patent Document 2] JP 2012-211439 A [Patent Document 3] JP 2011-246910 A [Patent Document 4] Japanese Patent Application Publication No. 11-6164 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when performing excavation work under the reverse-wound slab or construction work of the framework, the structural columns and intermediate piles below the reverse-wound slab interfere with the work, reducing work efficiency (unit rate) and lengthening the work process. For this reason, there was a demand for a technology to hold down the reverse-wound slab without using structural columns or intermediate piles.

[0005] The present invention has been made in consideration of the above, and aims to provide a deck slab retaining structure and method capable of retaining a deck slab without using structural columns or intermediate piles. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the deck retention structure of the present invention is a structure for retaining a deck installed between opposing earth retaining walls to the earth retaining walls, and is characterized in that it comprises a first connecting member that protrudes laterally from the earth retaining wall and is connected to the side end portion of the deck to retain the deck to the earth retaining wall, and a second connecting member that is connected from the earth retaining wall diagonally above the deck to the upper side of the deck to retain the deck to the earth retaining wall.

[0007] In addition, the method of retaining a deck according to the present invention is a method of retaining a deck, which is erected between opposing retaining walls, to the retaining walls, and is characterized in that it includes a step of fixing one side of a first connecting material to the retaining wall and connecting a side end portion of the deck to the other side of the first connecting material, and a step of fixing one side of a second connecting material to the retaining wall diagonally above the deck, and connecting the upper portion of the deck to the other side of the second connecting material. Effect of the Invention

[0008] According to the floor slab retaining structure of the present invention, a structure for retaining a floor slab erected between opposing earth retaining walls to the earth retaining walls includes a first connecting member protruding laterally from the earth retaining wall and connecting to the side end of the floor slab to hold the floor slab to the earth retaining wall, and a second connecting member connecting to the upper side of the floor slab from the earth retaining wall diagonally above the floor slab to hold the floor slab to the earth retaining wall, thereby achieving the effect of being able to hold the floor slab without using structural columns or intermediate piles. Since there is no need to install structural columns or intermediate piles, the ground under the floor slab can be excavated while avoiding interference with the structural columns or intermediate piles, and the construction of the framework by reverse winding construction can be efficiently performed.

[0009] In addition, according to the method for holding a floor slab according to the present invention, a method for holding a floor slab erected between opposing earth retaining walls to the earth retaining walls includes a step of fixing one side of a first connecting member to the earth retaining wall and connecting a side end of the floor slab to the other side of the first connecting member, and a step of fixing one side of a second connecting member to the earth retaining wall diagonally above the floor slab and connecting an upper part of the floor slab to the other side of the second connecting member, so that the floor slab can be held without using structural columns or intermediate piles. Since there is no need to install structural columns or intermediate piles, the ground under the floor slab can be excavated while avoiding interference with structural columns and intermediate piles, and the construction of the framework by reverse winding construction can be efficiently performed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an embodiment of a deck retaining structure and a retaining method according to the present invention. [Diagram 2] FIG. 2 is a photograph showing an example of the first connecting material of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a deck retaining structure and a retaining method according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these preferred embodiments.

[0012] As shown in Fig. 1, a deck retaining structure 10 according to an embodiment of the present invention retains a back-wound slab 14 (floor slab) to be erected between earth-retaining walls 12 by a back-wound construction method, to the earth-retaining walls 12, and includes a first connecting member 16 and a second connecting member 18. Note that the example shown in the figure shows a state in which excavation of the ground G has been completed up to the area below the back-wound slab 14.

[0013] The retaining wall 12 is an underground wall driven vertically into the supporting ground in the ground G, and is composed of, for example, steel sheet piles or steel pipe sheet piles. This retaining wall 12 is arranged so as to surround the ground G in the area in which the underground structure is to be constructed. The arrangement shape of the retaining wall 12 is assumed to be rectangular in plan view, but the present invention is not limited to this and other shapes may be used. A temporary gantry 20 is installed on the upper end of the retaining wall 12. The temporary gantry 20 is supported by intermediate piles 24 via H-shaped steel 22.

[0014] In the area where excavation has been completed, wales 28 are installed via brackets 26 on the surface of the retaining wall 12 above the inverted slab 14, and struts 30 are hung between the opposing wales 28 via intermediate piles 24. The struts 30 and wales 28 function as retaining supports. The example in the figure shows a case where two upper and lower struts 30A, 30B are installed. The struts 30A, 30B of each stage are constructed when excavation is completed to a specified depth.

[0015] The intermediate piles 24 are installed in the ground G to prevent buckling of the struts 30A, 30B. In the example shown in the figure, the planar positions and the number of intermediate piles 24 are shown as two piles installed at positions that divide the area between the retaining walls 12 on both sides into approximately three equal parts, but these can be changed depending on the required load conditions.

[0016] The back-wound slab 14 is a floor slab made of reinforced concrete, and constitutes a part of the skeleton of the underground structure (for example, the upper floor slab of the skeleton). The side end 32 of the back-wound slab 14 is fixed to the opposing retaining wall 12 via a first connecting member 16. In addition, two positions 36 that divide the upper surface 34 of the back-wound slab 14 into three equal parts are fixed to the retaining wall 12 diagonally above via a second connecting member 18. Therefore, the back-wound slab 14 also functions as a retaining support. The back-wound slab 14 is integrated with the lower part of the intermediate pile 24. In the example shown in the figure, the lower part of the intermediate pile 24 protrudes downward from the lower surface 38 of the back-wound slab as shown by the broken line and is embedded in the ground so that it can support the temporary girders 20 until the back-wound slab 14 is constructed. The intermediate pile 24 removes its lower portion from the underside 38 of the inverted slab 14 when the area below the inverted slab 14 is excavated.

[0017] The first connecting member 16 is provided to transmit the load of the back-wound slab 14 to the retaining wall 12, protrudes laterally from the retaining wall 12, and is connected to the side end 32 of the back-wound slab 14 to hold the back-wound slab 14 to the retaining wall 12. One end of the first connecting member 16 may be fixed to the surface of the retaining wall 12 by welding or the like, or may be embedded in the retaining wall 12. The other end of the first connecting member 16 is preferably embedded in the retaining wall 14. FIG. 2 shows an example of the first connecting member 16 protruding from the retaining wall 12 before the construction of the back-wound slab 14. The back-wound slab 14 is constructed on this first connecting member 16 in a later process. As shown in this figure, the first connecting member 16 can be composed of a plurality of steel materials such as reinforcing bars and steel rods, dowels, etc., arranged at intervals in the vertical and longitudinal directions.

[0018] The second connecting member 18 is a tensile diagonal member that connects the retaining wall 12 diagonally above the back-wound slab 14 to the upper surface 34 (upper part) of the back-wound slab 14 to hold the back-wound slab 14 to the retaining wall 12, and is provided to reduce the bending span of the back-wound slab 14. Specifically, the upper end of the second connecting member 18 is fixed to the lower-stage wale 28B provided on the retaining wall 12 via a bracket 40. The lower end of the second connecting member 18 is fixed to a position 36 that divides the upper surface 34 of the back-wound slab 14 into approximately three equal parts via an H-shaped steel 42. This position 36 is a position near the intermediate pile 24 located on the side closer to the upper end of the second connecting member 18. The second connecting member 18 can be made of a high-tensile material such as steel, for example.

[0019] Next, a method for retaining the deck according to this embodiment will be described. First, the retaining wall 12 is constructed in the ground G. Next, the ground G in the area surrounded by the retaining wall 12 is excavated, and the brackets 26A and wales 28A are constructed on the exposed retaining wall 12, after which the upper (first) strut 30A is erected. The intermediate piles 24 can be installed before or after the construction of the retaining wall 12, but before the upper strut 30A is erected. The temporary gantry 20 can be installed after the intermediate piles 24 are installed. Then, the area below the upper strut 30A is excavated to a predetermined depth, and the lower (second) strut 30B is erected.

[0020] After completing excavation up to the planned construction position of the back-wound slab 14, one side of the first connecting member 16 is attached to the retaining wall 12. Then, the back-wound slab 14 is constructed. At that time, concrete is poured so that the other end of the first connecting member 16 is embedded in the side end portion 32 of the back-wound slab 14, and further so that the intermediate pile 24 is wrapped around it. Then, the second connecting member 18 is hung between the upper surface 34 of the back-wound slab 14 and the lower wale 28B provided on the retaining wall 12. As a result, the back-wound slab 14 is held to the retaining wall 12 via the first connecting member 16 and the second connecting member 18. Then, excavation is continued in the ground G below the back-wound slab 14 to form a flooring surface, and leveling concrete 44 is constructed on this flooring surface.

[0021] In this way, the reverse-wound slab 14 is held by using the first connecting member 16 and the second connecting member 18 installed on the earth retaining wall 12 instead of the structural pillars and intermediate piles 24. Therefore, according to this embodiment, the reverse-wound slab 14 can be held on the earth retaining wall 12 without using the structural pillars and intermediate piles 24. Since it is no longer necessary to install the structural pillars and intermediate piles 24 below the reverse-wound slab 14, the space below the reverse-wound slab 14 is secured. Therefore, the ground G below the reverse-wound slab 14 can be excavated while avoiding interference with the structural pillars and intermediate piles 24, and the construction of the skeleton by the reverse-wound construction method can be efficiently performed. This improves the construction work rate of excavation and skeleton construction, and shortens the process. Furthermore, according to this embodiment, even if a structure (for example, a shield tunnel, etc.) exists below the bottom of the excavation, interference with the structure can be avoided, and the underground skeleton can be efficiently constructed by the reverse-wound construction method.

[0022] As described above, the floor slab retaining structure according to the present invention is a structure for retaining a floor slab erected between opposing earth retaining walls to the earth retaining walls, and includes a first connecting member protruding laterally from the earth retaining wall and connecting to the side end of the floor slab to hold the floor slab to the earth retaining wall, and a second connecting member connecting from the earth retaining wall diagonally above the floor slab to the upper side of the floor slab to hold the floor slab to the earth retaining wall, so that the floor slab can be held without using structural columns or intermediate piles. Since there is no need to install structural columns or intermediate piles, the ground under the floor slab can be excavated while avoiding interference with the structural columns or intermediate piles, and the construction of the framework by reverse winding construction can be efficiently performed.

[0023] In addition, according to the method for holding a deck according to the present invention, a method for holding a deck installed between opposing earth retaining walls to the earth retaining walls includes a step of fixing one side of a first connecting member to the earth retaining wall and connecting a side end of the deck to the other side of the first connecting member, and a step of fixing one side of a second connecting member to the earth retaining wall diagonally above the deck and connecting an upper part of the deck to the other side of the second connecting member, so that the deck can be held without using structural columns or intermediate piles. Since there is no need to install structural columns or intermediate piles, the ground under the deck can be excavated while avoiding interference with the structural columns and intermediate piles, and the construction of the framework by reverse winding construction can be efficiently performed. [Industrial Applicability]

[0024] INDUSTRIAL APPLICABILITY As described above, the deck slab retaining structure and retaining method of the present invention are useful for deck slabs in reverse winding construction methods, and are particularly suitable for retaining deck slabs without using structural columns or intermediate piles. [Explanation of symbols]

[0025] 10 Deck support structure 12 Earth retaining wall 14 Reverse-wound slab (floor slab) 16 First connector 18 Second connector 20 Temporary Platform 22,42 H section steel 24 Intermediate pile 26,26A,26B,40 Bracket 28, 28A, 28B Belly up 30,30A,30B strut 32 Side edge 34 Top surface (upper part) 36 positions 38 Bottom side 44 Leveling concrete G. Ground

Claims

1. A structure in which a floor slab installed between opposing earth retaining walls is held by the earth retaining walls, A deck retention structure characterized by comprising a first connecting material that protrudes laterally from the retaining wall and is connected to the side end of the deck to hold the deck to the retaining wall, and a second connecting material that is connected from the retaining wall diagonally above the deck to the upper side of the deck to hold the deck to the retaining wall.

2. A method for holding a deck slab installed between opposing earth retaining walls to the earth retaining walls, comprising: A method for retaining a deck slab, comprising the steps of fixing one side of a first connecting material to the retaining wall and connecting the side end of the deck slab to the other side of the first connecting material, and fixing one side of a second connecting material to the retaining wall diagonally above the deck slab and connecting the upper portion of the deck slab to the other side of the second connecting material.

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