Methods for constructing underground structures, underground structures, connection structures

Abstract

This invention provides a method for constructing underground structures that allows for the installation of small beams without prolonging the construction period. [Solution] The method for constructing an underground structure includes: a column erection step of erecting at least two pairs of temporary support columns 21 on piles or a pressure-resistant slab; a temporary beam installation step of installing a temporary beam 51 made of steel frame between one pair of temporary support columns 21; a first beam installation step of installing a first beam 30 made of steel frame between the other pair of temporary support columns 21; a secondary beam installation step of installing a secondary beam 60 made of steel frame between the temporary beam 51 and the first beam 30; and a second beam construction step of constructing a second beam 50 including reinforced concrete so as to embed the temporary beam 51.

Description

Technical Field

[0001] The present invention relates to a method for constructing an underground structure and an underground structure.

Background Art

[0002] Conventionally, as a method for constructing a structure including an underground structure and a ground structure, there is known a two-stage construction method in which the ground is excavated to construct a main foundation, a first-floor is constructed by being supported by columns erected on the main foundation, and the construction work of the underground structure and the ground structure is carried out simultaneously using the first-floor as a working floor (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, the underground structure may be made of reinforced concrete or a mixed structure of steel-reinforced concrete and steel. Figure 14 shows an example of a foundation with a mixed structure of reinforced concrete and steel. In the mixed structure foundation 110 shown in Figure 14, the beam 150 between column A1 120 and column A2 120 (hereinafter referred to as A1-A2), the beam 150 between A2-A3, and the beam 140 between A1-B1 are made of reinforced concrete. The beams 130 between B1-B2, B2-B3, A2-B2, and A3-B3 are made of steel. Secondary beams 160 are provided between the beam 150 between A1-A2 and the beam 130 between B1-B2, and between the beam 150 between A2-A3 and the beam 130 between B2-B3. To construct such a mixed structure, steel beams 130 were erected, reinforced concrete beams 140 and 150 were constructed, and then secondary beams 160 were placed between the steel beams 130 and the reinforced concrete beams 150. As a result, the pouring and curing of the concrete that makes up the reinforced concrete beams took time, delaying the installation of the secondary beams and resulting in a prolonged construction period.

[0005] This invention has been made in view of the above-mentioned problems, and its objective is to provide a method for constructing an underground structure that allows for the installation of small beams without prolonging the construction period. [Means for solving the problem]

[0006] According to one aspect of the present invention, a method for constructing an underground structure is provided, comprising: a steel column erection step of erecting at least two pairs of steel columns on piles or a pressure-resistant slab; a temporary beam installation step of installing a temporary beam made of steel between one pair of steel columns; a first beam installation step of installing a first beam made of steel between the other pair of steel columns; a secondary beam installation step of installing a secondary beam made of steel between the temporary beam and the first beam; and a second beam construction step of constructing a second beam by pouring concrete to embed the temporary beam. The temporary beam installation step and the first beam installation step may be performed simultaneously.

[0007] According to the above embodiment, since a temporary beam made of steel is pre-erected between one pair of steel columns, secondary beams can be erected before the reinforced concrete beam is constructed. As a result, the secondary beams can be erected without waiting for the concrete of the second beam to be poured and hardened, thus shortening the construction period.

[0008] According to one aspect of the present invention, the lower parts of one and the other steel columns are exposed, and a foundation concrete pouring step is performed in which concrete is poured to embed a portion of the steel columns, along with a second beam construction step.

[0009] Because the lower part of the steel column is exposed in this way, temporary beams can be connected to the lower part of the steel column.

[0010] According to one aspect of the present invention, a gusset plate is attached to the temporary beam, and one end of the secondary beam is connected to the gusset plate.

[0011] By attaching gusset plates to the temporary beams in advance, the connection of the secondary beams can be done quickly and easily.

[0012] According to one aspect of the present invention, the structure includes a first beam made of steel frame provided between one pair of steel columns, a second beam provided between the other pair of steel columns, and a secondary beam made of steel frame spanning between the first beam and the second beam, wherein the second beam includes a reinforced concrete structure and a temporary beam made of steel frame, at least a portion of which is embedded in the reinforced concrete structure, and the secondary beam is connected to the temporary beam and the first beam.

[0013] According to the above embodiment, secondary beams can be erected before the reinforced concrete frame is constructed, thereby shortening the construction period.

[0014] According to one aspect of the present invention, the other pair of columns each have steel columns embedded in a concrete structure, and the leading beam has both ends connected to the steel columns of the other pair of columns.

[0015] According to the above aspect, the front girder can be attached to the steel column in advance.

[0016] According to one aspect of the present invention, there is provided a connection structure between a beam and a secondary beam of an underground structure, wherein the beam includes a reinforced concrete structure and steel is embedded in a side portion thereof, the secondary beam is made of steel, and an end portion of the secondary beam is connected to the steel embedded in the beam.

Effects of the Invention

[0017] According to the present invention, it is possible to provide a construction method for an underground structure in which a secondary beam can be installed without prolonging the construction period.

Brief Description of the Drawings

[0018] [Figure 1] It is a longitudinal sectional view showing a part of an underground structure according to the present embodiment. [Figure 2] It is a sectional view taken along line II-II in FIG. 1. [Figure 3] It is an enlarged sectional view showing a detailed configuration of a connection portion between an H-shaped steel embedded in a side surface of a beam and a secondary beam. [Figure 4] It is a front view showing a state in which columns are erected in a construction method of an underground structure. [Figure 5] It is a plan view showing a state in which columns are erected in a construction method of an underground structure. [Figure 6] It is a longitudinal sectional view showing a state in which a secondary beam is built in a construction method of an underground structure. [Figure 7] FIG. 6 is a sectional view taken along line VI-VI in FIG. 7. [Figure 8] It is a longitudinal sectional view showing a state in which a steel beam is built in a construction method of an underground structure. [Figure 9] It is a sectional view taken along line IX-IX in FIG. 8. [Figure 10] It is a longitudinal sectional view showing a state in which concrete is placed in a construction method of an underground structure. [Figure 11] It is a sectional view taken along line XI-XI in FIG. 10. [Figure 12]It is a longitudinal sectional view showing a state where a first-floor slab is constructed in a method for constructing an underground structure and concrete is placed around a steel column. [Figure 13] It is the XIII-XIII cross-section in Fig. 12 [Figure 14] It is a diagram showing an example of a foundation of a conventional hybrid structure of reinforced concrete and steel frame construction.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, in the drawings, the shape of the H-shaped steel constituting the beam is shown as a rectangle.

[0020] Fig. 1 is a longitudinal section showing a part of an underground structure according to this embodiment, and Fig. 2 is a II-II cross-sectional view in Fig. 1. Note that Fig. 1 shows the I-I cross-section in Fig. 2. The underground structure 1 is constructed in an underground space formed by constructing a retaining wall in the ground and excavating inside the retaining wall. As shown in Figs. 1 and 2, the underground structure 1 includes a foundation structure 10 and columns 20 constructed on the foundation structure 10. The columns 20 are arranged side by side in the horizontal direction in Fig. 2 and are also arranged side by side in the vertical direction in Fig. 2. For the sake of the following description, the steel columns 21 arranged vertically in Figs. 2 and 3 are designated as columns A and B from top to bottom, and the steel columns 21 arranged horizontally are designated as rows 1 to 3 from left to right. Hereinafter, for example, the steel column in column A, row 1 is referred to as the steel column A1, and the beam between the columns A1 and A2 of the steel column is referred to as the beam between A1 - A2, etc.

[0021] The foundation structure 10 includes a pressure-resistant disk 11, piles 12 connected below the pressure-resistant disk 11, a foundation 13 on the pressure-resistant disk 11, and beams (foundation beams). The pressure-resistant disk 11 is formed at the bottom of the excavation in the retaining wall to the floor depth. Also, the piles 12 are constructed, for example, by excavating the ground with an auger or the like, injecting a ground improvement liquid, inserting a core material such as steel into the excavation hole, or arranging a steel cage in the excavation hole and then placing concrete.

[0022] Each of the columns 20 constituting the foundation 13 includes a core steel column 21 and a concrete structure 22 surrounding the steel column 21. The steel column 21 is erected on the pressure-resistant slab 11. In the steel column 21, the portion embedded in the foundation 13 or foundation beam later becomes a temporary support, and the portion above that later becomes part of the permanent column (column 20). The column 20 is the portion above the foundation 13 or foundation beam and is composed of the steel column 21 and the concrete structure 22 surrounding the steel column 21. Here, a cross H-beam, in which the webs of two H-beams intersect, is used as the steel column 21 for explanation. The steel column 21 can be made from H-beams, square steel pipes, a four-sided box made by welding four thick plates, etc., as appropriate. Also, in the steel column 21, the shape of the steel frame may differ between the temporary support and the permanent column.

[0023] The foundation beams include a reinforced concrete beam 40 and a reinforced concrete beam 50. Additionally, steel beams 30 and temporary beams 51 are provided between the steel columns 21. The beams 30 between A2-B2, B1-B2, and B2-B3 are made of steel (H-shaped steel), with each end connected to the flange of the steel column 21. The beam 40 between A1-B1 is made of reinforced concrete. The beams 50 between A1-A2 and A2-A3 are made of reinforced concrete. Furthermore, temporary beams 51 made of steel (H-shaped steel) are embedded in the side of beam 50 on the B-row side, with both ends of the temporary beams 51 connected to the flanges of the steel columns 21. The temporary beams 51 may be entirely embedded within the concrete structure or exposed on the side of the concrete structure. In this example, the temporary beam 51 is an H-shaped steel beam, but I-shaped steel beams, angle steel beams, channel steel beams, etc., can be used as appropriate.

[0024] The secondary beam 60 is connected at one end to the steel beam 30, and at the other end to a temporary beam 51 embedded in the side of the beam 50. Figure 3 is an enlarged cross-sectional view showing the detailed configuration of the connection between the temporary beam 51 embedded in the side of the beam 50 and the secondary beam 60, and is the III-III cross-sectional view in Figure 2. As shown in Figure 3, a gusset plate 53 is attached to the outer surface of the temporary beam 51 embedded in the beam 50. The gusset plate 53 is provided perpendicular to the web of the temporary beam 51. The upper and lower edges of the gusset plate 53 are welded to the flange, and one edge is welded to the web. The end of the secondary beam 60 is bolted to the gusset plate 53, so that the secondary beam 60 is integrated with the temporary beam 51. In addition, a stud 54 is attached to the inner surface of the web of the temporary beam 51. This stud 54 integrates the temporary beam 51 with the concrete structure 52 that constitutes the beam 50. The secondary beam 60 is made of steel. In this case, the secondary beam 60 is an H-shaped steel, but I-shaped steel, angle steel, channel steel, etc. can be used as appropriate.

[0025] A first-floor slab 70 is constructed on top of the column 20, and the first-floor slab 70 is supported by the column 20 so that construction work on the superstructure can be carried out above it. In addition, a floor slab 80, which constitutes the basement floor, is constructed on top of beams 30, 40, 50 and secondary beams 60.

[0026] The following describes the method for constructing the underground structure according to this embodiment. Figures 4 and 5 show the state in which steel columns have been erected in the construction method of an underground structure, with Figure 4 being a front view and Figure 5 being a plan view. When constructing an underground structure, first, as shown in Figure 4, the ground is excavated to the floor depth and a pressure-resistant slab 11 is constructed. Then, steel columns 21 are erected at a position above the piles 12 (steel column erection step). The lower part of the steel column 21 erected here is embedded in the concrete of the foundation or foundation beam and becomes a temporary column (this temporary support part is called the lower part of the steel frame 21A), and the upper part is embedded in the permanent column (column 20) (this permanent column part is called the upper part of the steel frame 21B). In this embodiment, a single steel column 21 is erected, but it is not limited to this, and a temporary steel column may be erected first, and then a steel column to be embedded in the permanent column may be erected on top of the temporary column.

[0027] Figure 6 is a vertical cross-sectional view showing the state in which steel beams have been erected in the construction method of the underground structure, and Figure 7 is a cross-sectional view of VII-VII in Figure 6. Note that Figure 6 shows the cross-sectional view of VI-VI in Figure 7. As shown in Figures 6 and 7, temporary beams 51 made of steel are placed between A1-A2 and A2-A3, and both ends of the temporary beams 51 are connected to the steel columns 21 (temporary beam installation step). Specifically, both ends of the temporary beams 51 are connected to the lower steel portion 21A that will serve as temporary supports for the steel columns 21. Gusset plates 53 and studs 54 are attached to the temporary beams 51 in advance. At this time, the temporary beams 51 are connected offset from the center of the flange of the cross H-shaped steel of the steel columns 21 to the side to which the secondary beams 60 are connected. Furthermore, beams 30, which are permanent beams made of steel, are placed between B1 and B2, and between B2 and B3, and both ends of the steel beams are connected to the flanges of the cross H-shaped steel of the steel columns 21 (first beam installation step). It is advisable to attach gusset plates to these beams 30 in advance to the parts to which the secondary beams 60 will be connected. Also, beams 30, which are permanent beams made of steel, are placed between the steel columns 21 (steel portion 21A that will be temporary columns) between A2 and B2, and both ends of the steel beams are connected to the flanges of the cross H-shaped steel of the steel columns 21. In addition, beams 71 are placed between the steel columns 21 on the first floor (steel portion 21B that will be embedded in the permanent columns).

[0028] Figure 8 is a longitudinal section showing the state in which secondary beams have been erected in the construction method of the underground structure, and Figure 9 is a cross-sectional view taken from IX-IX in Figure 8. Figure 8 shows a cross-sectional view taken from VIII-VIII in Figure 9. As shown in Figures 8 and 9, a secondary beam 60 made of H-shaped steel is then placed between the temporary beam 51 between A1 and A2 and the beam 30 between B1 and B2, and the ends of the secondary beam 60 are connected to the web of the temporary beam 51 and the web of the beam 30 (secondary beam installation step). At this time, the ends of the secondary beam 60 can be easily connected by attaching gusset plates to the web of the temporary beam 51 and the web of the beam 30 in advance. Similarly, a secondary beam 60 is placed between the web of the temporary beam 51 between A2 and A3 and the web of the beam 30 between B2 and B3, and the ends of the secondary beam 60 are connected to the web of the temporary beam 51 and the web of the steel beam 30. Secondary beams 72 are also placed between opposing beams on the first floor.

[0029] Figures 10 and 11 are longitudinal cross-sectional views showing the state after concrete has been poured in the construction method of the underground structure, with Figure 11 being the cross-sectional view between XI-XI in Figure 10. Figure 10 shows the cross-sectional view XX in Figure 11. As shown in Figures 10 and 11, the reinforcement of the reinforced concrete beam 40 between A1 and B1, and the reinforced concrete beams 50 between A1 and A2 and between A2 and A3 are then poured. Then, concrete is poured at the positions corresponding to the steel column 21 and the beams 40 between A1 and B1 and the beams 50 between A1 and A2 and A2 and A3 (second beam construction step). In this process, the reinforcement of the foundation 13 and the pouring of concrete are also carried out (foundation concrete pouring step). Once the poured concrete hardens, the construction of the reinforced concrete beams 40 and 50 and the foundation 13 is completed. In parallel with or after this, the basement floor slab 80 is constructed. The basement floor slab 80 can be constructed, for example, by placing deck plates, reinforcing the floor, and then pouring concrete.

[0030] Figures 12 and 13 are longitudinal cross-sectional views showing the construction of the first-floor slab in the underground structure construction method, with concrete 22 poured around the steel column 21 (the upper steel portion 21B included in the permanent column). Figure 13 is the XIII-XIII section in Figure 12. Figure 12 shows the XII-XII section in Figure 13. The floor slab 70 is constructed on the beams 71 and secondary beams 72 of the first floor. The first-floor slab 70 can be constructed, for example, by placing deck plates, arranging floor reinforcement, and then pouring concrete 73.

[0031] Next, concrete 22 is poured around the steel columns 21 (the upper steel portion 21B included in the permanent columns) on the foundation 13 and foundation beams (beams 40, 50) (column concrete pouring step). Once the poured concrete hardens, the construction of the floor slab 70, floor slab 80, and columns 20 is completed. With these steps, the construction of the underground structure 1 is completed.

[0032] The construction process for the floor slab 70 may be carried out after the beam installation step shown in Figures 8 and 9, and before the second beam construction step shown in Figures 10 and 11.

[0033] According to this embodiment, the following effects are achieved. The method for constructing an underground structure according to this embodiment includes a temporary beam installation step of installing a temporary beam 51 made of steel between one pair of steel columns 21, a first beam installation step of installing a beam 30 made of steel between the other pair of steel columns 21, a secondary beam installation step of installing a secondary beam 60 made of steel between the temporary beam 51 and the steel beam 30, and a second beam construction step of constructing a beam 50 including reinforced concrete so as to embed the temporary beam 51.

[0034] As a result, a temporary beam 51 made of steel is pre-erected between one pair of steel columns 21, allowing the secondary beams 60 to be erected before the main beam 50, which includes reinforced concrete, is constructed. This shortens the construction period because the secondary beams 60 can be erected without waiting for the concrete of the reinforced concrete beam 50 to be poured and hardened.

[0035] Furthermore, according to this embodiment, the lower parts of one and the other steel column 21 are exposed, and together with the second beam construction step, a concrete pouring step for the foundation is performed in which concrete is poured to bury a part of the steel column 21 (all of the steel portion that will later become a temporary support). Prior to the concrete pouring steps for the foundation and foundation beam, the temporary beam 51 can be connected to the lower part of the steel column 21.

[0036] Furthermore, according to this embodiment, a gusset plate 53 is attached to the temporary beam 51, and one end of the secondary beam 60 is connected to the gusset plate 53. By attaching the gusset plate 53 to the temporary beam 51 in this way, the connection of the secondary beam 60 can be performed quickly and easily. [Explanation of Symbols]

[0037] 1: Underground structure 10:Fundamental structure 11: Pressure-resistant plate 12:Pile 13: Basics 20: Pillar 20A:Column member 21: Cross H-beam 21A: Cross H-beam 22: Concrete structure 22A: Concrete structure 30: Beam (steel beam) 40: Beam (reinforced concrete beam) 50: Beam (reinforced concrete beam) 51: Cross H-beam 51: Temporary beam (H-shaped steel) 52: Concrete structure 53: Gusset Plate 54: Stud 60: Small beam 70: First floor slab 71: Beam 72: Small beam 73: Concrete 80: Floor slab

Claims

1. A method for constructing underground structures, A steel column erection step for erecting at least two pairs of steel columns on a pile or pressure-resistant slab, A temporary beam installation step is used to install a temporary beam made of steel between two pairs of steel columns, A first beam installation step involves installing a first beam made of steel between the other pair of steel columns, A secondary beam installation step is provided, in which a secondary beam made of steel is installed between the temporary beam and the first beam. A second beam construction step involves constructing a second beam, including reinforced concrete, so as to embed the aforementioned temporary beam, A method for constructing underground structures, including [the specified element].

2. The aforementioned steel columns one and the other are exposed. Along with the second beam construction step, a concrete pouring step for the foundation is performed, in which concrete is poured to bury the lower part of the steel column. A method for constructing an underground structure according to claim 1.

3. A gusset plate is attached to the aforementioned temporary beam. The aforementioned joist is connected at one end to the gusset plate. A method for constructing an underground structure according to claim 1.

4. A first beam made of steel is provided between one pair of steel columns, A second beam is provided between the other pair of steel columns, It has a secondary beam made of steel frame that spans between the first beam and the second beam, The second beam includes a reinforced concrete structure and a temporary beam made of steel frame, at least a portion of which is embedded in the reinforced concrete structure. The secondary beam is connected to the temporary beam and the first beam. Underground structures.

5. The temporary beam is connected at both ends to the other pair of steel columns. The underground structure according to claim 3.

6. A connection structure between beams and joists in an underground structure, The aforementioned beam is made of reinforced concrete and has steel frames embedded in its sides. The aforementioned secondary beam is made of steel, and the ends of the secondary beam are connected to the steel embedded in the main beam. Connection structure.

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