JP7702218B2 - Method for constructing structure and structure - Google Patents

Description

The present invention relates to a structure composed of an above-ground structure and an underground structure separated by a leading floor used for a work platform, and a method for constructing the same.

Conventional methods for constructing structures consisting of an underground framework and an aboveground framework include the inverted construction method, in which underground and aboveground framework construction is carried out in parallel, as well as the two-stage construction method, in which a foundation is constructed at the bottom of an excavation trench constructed by excavating the ground, and the first floor is supported by pillars erected on this foundation and constructed at approximately the same height as the ground surface. After that, the first floor is used as a work floor and construction work on the underground framework and aboveground framework is carried out simultaneously (Patent Document 1).

In the upside-down construction method, excavation is performed while burying structural columns that will not be necessary for the completed underground structure, and the underground structure is constructed from the upper floors onwards, which makes it difficult to control the accuracy and increases construction costs. In addition, in the two-stage construction method, the first floor is constructed early after the foundations are built and the steel columns are erected, so the entire excavation trench (underground space) is blocked by the first floor before the underground structure is constructed. This makes it difficult to transport the underground structure components into the excavation trench using a lifting machine such as a crane installed on the ground surface, which can result in low construction efficiency.

Therefore, the applicant developed a structure construction method including the following steps (Patent Document 2).
(1) An excavation trench construction process for excavating the ground and constructing an excavation trench for constructing an underground structure.
(2) A divided underground structure construction process, in which a divided underground structure is constructed in a part of the excavation trench adjacent to the ground and a lifting machine is installed on the divided underground structure.
(3) A process of expanding a divided underground structure by using a lifting machine to expand another divided underground structure adjacent to the divided underground structure.
(4) A structure construction process in which an underground structure consisting of multiple divided underground structures is constructed within the excavation trench by repeating the divided underground structure expansion process the required number of times, and an aboveground structure is constructed on the divided underground structures.

Patent No. 3053938 JP 2004-176434 A

However, even with conventional methods for constructing structures, construction of the underground structure can take a long time due to various factors. In such cases, construction of the above-ground structure may proceed up to the construction of the roof, but there is concern that an earthquake may occur before the underground structure is completed, and safety measures are required to prevent this.

The present invention was made to solve the above problems, and aims to provide a method for constructing a structure and a structure that can ensure safety in the event of an earthquake during the long construction period.

In view of the above problems, the present invention provides a method for constructing a structure composed of an above-ground structure and an underground structure bounded by a preceding floor, the method comprising: a ground excavation step of providing a retaining wall having a core material and excavating the ground to the depth of the flooring surface; a foundation structure construction step of constructing a foundation structure on the flooring surface; a subway frame construction step of erecting a steel frame structure composed of columns and beams on the foundation structure; and a preceding floor construction step of constructing the preceding floor with an outer perimeter beam on the top of the steel frame structure and connecting the retaining wall and the outer perimeter beam via a shear transfer member, the preceding floor being constructed as a work platform for constructing the above-ground structure, thereby performing construction work for the above-ground structure and the underground structure in parallel (hereinafter, the above-mentioned method for constructing a structure may be referred to as "this construction method").

In addition, in this construction method, it is preferable that the outer perimeter beam is provided with main reinforcement bars, shear reinforcement bars (stirrups), and outer perimeter reinforcement bars for reinforcing the periphery of the shear transmission member.

In addition, in this construction method, the outer peripheral reinforcement comprises axial reinforcement (axial steel bar) arranged parallel to the retaining wall, and surrounding reinforcement formed in a U-shape surrounding the shear transmission member and at least a portion of the shear reinforcement , and it is preferable that the surrounding reinforcement is arranged to connect the shear reinforcement and the shear transmission member in a manner that surrounds the shear transmission member and embraces and surrounds the vertical portion of the shear reinforcement on the retaining wall side and the upper and lower ends connected to the vertical portion .

Here, the preliminary floor is a floor structure that is the boundary between the above-ground structure and the underground structure, and is used as a work platform for constructing the above-ground structure. However, the preliminary floor does not need to be formed strictly in line with the ground surface of the target ground.
The shear transfer member is a member provided to transfer the shear force between the perimeter beam and the earth retaining wall, and the type of the member does not matter. For example, a steel rod such as a stud can be used as the shear transfer member, and it is preferable that it is joined to the core material to enhance its effect.

In addition, the surrounding reinforcement is a steel bar that is arranged around the shear transmission member and at least a portion of the shear reinforcement, and serves to surround (embrace) the shear transmission member and the shear reinforcement to reinforce (connect) them (including a form in which it partially surrounds them), and it is preferable for it to be in an appropriate shape such as a C-shape, U-shape, C-shape, hoop shape, etc.
In addition, the main reinforcement, shear reinforcement, and peripheral reinforcement (axial reinforcement and surrounding reinforcement) used in the peripheral beams can be of appropriate standards and numbers depending on the construction situation.

There is also no limitation on the structure of the earth retaining wall including the core material, and it can be constructed by, for example, a soil cement column wall method, a diaphragm wall method, etc. As for the core material to be used, various steel materials such as H-shaped steel, I-shaped steel, etc. can be used.
Furthermore, there are no limitations on the target structure with respect to this construction method and this structure (the content described in this paragraph also applies to the structure of the present invention described below).

This construction method includes a preliminary floor construction process, in which a retaining wall having a core material is joined to the preliminary floor via a perimeter beam, and a shear transfer member is provided at the joint between the perimeter beam and the retaining wall. This makes it possible to firmly integrate the preliminary floor and the retaining wall, ensuring sufficient safety during earthquakes during construction.

The present invention also relates to a structure that is composed of an underground structure that is an upper part of a foundation structure and is constructed inside an earth retaining wall having a core material, and an aboveground structure that is constructed on the upper part of the underground structure via a preceding floor, and in which the aboveground structure and the underground structure are constructed in parallel, a perimeter beam having main reinforcement, shear reinforcement, and peripheral reinforcement for reinforcing the periphery of a shear transfer member is interposed at a joint between the preceding floor and the earth retaining wall, and the shear transfer member and the peripheral reinforcement provided in the core material are provided at a joint between the earth retaining wall and the peripheral beam. The structure (hereinafter sometimes referred to as "this structure") is characterized in that the outer peripheral reinforcement comprises axial reinforcement arranged parallel to the retaining wall, and surrounding reinforcement formed in a U-shape surrounding the shear transmission member and at least a portion of the shear reinforcement, and the surrounding reinforcement is arranged to connect the shear reinforcement and the shear transmission member in a manner that surrounds the shear transmission member and embraces and surrounds the vertical portion of the shear reinforcement on the retaining wall side and the upper and lower ends connected to the vertical portion.

This structure is a structure that has been constructed or is currently being constructed by constructing aboveground and underground structures in parallel, and is preferably constructed using this construction method, but the construction method is not critical.

In addition, while this structure is constructed in such a way that the above-ground structure and the underground structure are constructed in parallel, the construction periods for the above-ground structure and the underground structure do not need to be exactly the same. It is sufficient that the construction periods for the above-ground structure and the underground structure overlap for a certain period of time by using the preceding floor for the construction of the above-ground structure.

In this structure, the retaining wall with a core material and the leading floor are joined via the perimeter beam, and the joint between the retaining wall and the perimeter beam is provided with a shear transfer member and perimeter reinforcement bar attached to the core material, so that the leading floor and the retaining wall can be firmly integrated, and safety in the event of an earthquake during construction can be fully ensured.

The present invention provides a method for constructing a structure and a structure that can ensure safety during earthquakes over a long construction period.

1 is a side cross-sectional view showing a ground excavation step in the method for constructing a structure of the present invention. FIG. 2 is a side cross-sectional view showing the foundation framework construction process in the method for constructing a structure of the present invention. FIG. 2 is a side cross-sectional view showing the subway frame construction process in the method for constructing a structure of the present invention. FIG. 2 is a side cross-sectional view showing the preliminary floor construction step in the method for constructing a structure of the present invention. 5A is an enlarged view of a portion X in FIG. 4, and FIG. 5B is a front view of the core material. FIG. 2 is a side cross-sectional view showing the structure of the present invention.

Below, an example of an embodiment of the present structure K constructed by the present construction method and the present construction method will be described in detail with reference to the drawings. Note that in the description based on the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted.

[This construction method]
This construction method is a method for constructing a main structure K which is composed of an above-ground structure U and an underground structure L, with a preceding floor 10 as its boundary.
This construction method includes (1) a ground excavation process, (2) a foundation framework construction process, (3) a subway frame erection process, and (4) a preliminary floor construction process, and uses the preliminary floor 10 as a work platform to carry out construction work for the above-ground framework U and the underground framework L in parallel. Each process will be described in detail below.

(1) Ground excavation process The ground excavation process is a process in which a retaining wall 20 having a core material 21 is constructed, the ground G is excavated to a predetermined depth, that is, the depth of the flooring surface G1, and an underground space section S for constructing an underground structure U is formed (Figure 1).
The retaining wall 20 is constructed to surround the periphery of the underground space S to be excavated, for example, by using a soil mixing wall method (SMW method) in which soil and a cement-based suspension are mixed and stirred in situ to form a diaphragm wall. The retaining wall 20 also has a predetermined number of H-shaped steel members (core members) arranged at predetermined intervals in the vertical direction as core members 21.

At this time, struts (not shown) are installed between opposing retaining walls 20 in sequence according to the depth of the excavation, reinforcing the retaining walls 20 while the excavation work is carried out.

(2) Foundation framework construction process The foundation framework construction process is a process of constructing the foundation framework, which is a pressure-resistant concrete plate 30, on the flooring surface G1 (FIG. 2). In this embodiment, a pile foundation is used, and foundation piles 31 are driven in, the pile heads are treated, and the flooring surface G1 is formed by flattening. Then, reinforcement is applied to the upper surface of the flooring surface G1 to a predetermined thickness, and the pressure-resistant concrete plate 30 is poured.
It is also possible to select other foundation types depending on the ground conditions, and the ground may be improved as appropriate.

(3) Subway Frame Construction Process The subway frame construction process is a process of erecting a steel frame 40 on top of the pressure plate concrete 30 (FIG. 3). This work is carried out by dismantling the struts (not shown) at predetermined locations below to secure a work space and assembling the steel frame 40, which is composed of multiple steel columns 41 and multiple steel beams 42, to the height of the advance floor 10.

(4) Pre-floor Construction Process The pre-floor construction process is a process in which a pre-floor 10 having a peripheral beam 50 is constructed around the top of the steel frame 40 so that the top surface is approximately flush with the top surface of the ground G, and the retaining wall 20 and the peripheral beam 50 are joined via studs 25 (shear transfer members) (Figure 4).

In addition, in order to carry out construction efficiently, it is preferable to set up a predetermined number of studs 25 at predetermined positions on the flange of the H-shaped steel, which is the core material 21 of the retaining wall 20, so that they protrude toward the outer perimeter beam 50 (Figure 5 (b)) before carrying out the preliminary floor construction process.

The advance floor 10 is constructed by placing the main reinforcement bars 12, stirrups 13, etc., including the outer perimeter beams 50 described below, at the top of the steel frame 40, and pouring concrete 11.

An outer perimeter beam 50 is integrally formed around the entire peripheral edge of the leading floor 10, and is joined to the retaining wall 20 at the portion of the outer perimeter beam 50.
A steel beam 42', which is an H-shaped steel, is joined to the steel column 41 at a location corresponding to the upper position of the outer peripheral beam 50 in a direction parallel to the retaining wall 20. A plurality of main reinforcing bars 61 are arranged in the horizontal direction near the left and right edge ends of the upper and lower flanges of the steel beam 42', and stirrups 62 (shear reinforcement bars) are arranged at predetermined intervals to surround the upper and lower main reinforcing bars 61 in the height direction. Further, on the lower side of the steel beam 42', a plurality of horizontal reinforcements 14 are arranged in a predetermined height direction in the horizontal direction, and a plurality of vertical reinforcements 15 are arranged at predetermined positions in the vertical direction.

Periphery reinforcement bars 65 are arranged at the joint 60 between the outer periphery beam 50 and the retaining wall 20.
The outer periphery reinforcement 65 includes a plurality of axial reinforcements 66 arranged parallel and horizontally to the retaining wall 20, and a surrounding reinforcement 67 formed in a U-shape (Figure 5 (a)).

Multiple axial reinforcements 66 are arranged at predetermined positions in different height directions and in the direction of the preceding floor 10, and in particular, the end side of the outer perimeter beam 50 close to the stud 25 is arranged so as to be densely packed.
The surrounding reinforcement bars 67 are arranged so that the U-shaped opening is on the opposite side to the earth retaining wall 20 to which it is joined, and so that their tips are located approximately in the center of the outer perimeter beam 50. The surrounding reinforcement bars 67 surround each stud 25, and are arranged to connect the stirrups 62 and the studs 25 in such a manner that they embrace and surround the vertical part of the stirrup 62 on the earth retaining wall 20 side and the upper and lower ends connected to the vertical part.

Then, concrete 11 is poured around each reinforcing bar and steel beam 42' to form the outer perimeter beam 50.

After this process is completed, the above-ground structure U is constructed upward using the leading floor 10 as a work platform, while construction of the underground structure L continues below the leading floor 10, completing the structure K (Figure 6).

This construction method includes a preliminary floor construction process, in which the earth retaining wall 20 having the core material 21 is joined to the preliminary floor 10 via the outer perimeter beam 50. A plurality of studs 25 attached to the core material 21 are provided at the joint 60 between the earth retaining wall 20 and the outer perimeter beam 50 to firmly join them, and the construction work of the above-ground structure U and the underground structure L can be carried out in parallel using the preliminary floor 10 as a work platform. In this way, the preliminary floor 10 and the earth retaining wall 20 can be firmly integrated, so that the safety of the above-ground structure U and the underground structure L during construction in the event of an earthquake can be fully ensured.

[This construct]
This structure K is composed of an above-ground structure U and an underground structure L, with the boundary being a pilot floor 10 used for a work platform, and is a structure constructed by constructing the above-ground structure U and the underground structure L in parallel (Figure 6).

This structure K is composed of an underground structure L constructed on top of a pressure-resistant concrete plate 30 constructed on the flooring surface G1, a preliminary floor 10 constructed on top of the underground structure L, and an above-ground structure U constructed on top of the preliminary floor 10.
The underground structure L is constructed in an underground space S formed inside a retaining wall 20, and the retaining wall 20 is provided with a plurality of core materials 21 cast at predetermined intervals.

A perimeter beam 50 is provided around the entire periphery (surrounding) of the leading floor 10, and the perimeter beam 50 is joined to the retaining wall 20. In other words, the perimeter beam 50 is interposed between the leading floor 10 and the retaining wall 20. The joint 60 between the retaining wall 20 and the perimeter beam 50 is provided with studs 25 attached to predetermined positions of the flange of the H-shaped steel, which is the core material 21, and with peripheral reinforcement bars 65 (details are the same as those explained in the construction method above).

According to this structure K, the retaining wall 20 with the core material 21 and the leading floor 10 are joined via the outer perimeter beam 50, and the joint 60 between the retaining wall 20 and the outer perimeter beam 50 is provided with a number of studs 25 attached to the core material 21 and outer perimeter reinforcement bars 65. This makes it possible to firmly integrate the leading floor 10 and the retaining wall 20, and sufficiently ensures the safety of the upper structure U and the lower structure L during construction in the event of an earthquake.

Although an example of a preferred embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and other necessary steps may be added to each element as appropriate within the scope of the present invention.

As described above, there are no limitations on the form of the wooden construction method and the various components of the structure, and the most suitable components can be used. In particular, the form of the wooden structure above ground and below ground, the preliminary floor, the foundation structure, the steel frame, and the perimeter beams can be appropriately determined according to the embodiment.
Furthermore, with regard to this construction method and this structure, the minimum necessary components are exemplified, and other steps and other components may be added as long as they do not impair the effects of the present invention.

K Structure U Above-ground structure L Underground structure G Ground G1 Floor surface 10 Pre-floor 20 Earth retaining wall 21 Core material 25 Stud (shear transfer member)
30 Pressure-resistant concrete (foundation structure)
31 Foundation pile 40 Steel frame 41 Steel column 42, 42' Steel beam 50 Periphery beam 60 Joint 61 Main reinforcing bar 62 Stirrup (shear reinforcement bar)
65 Periphery reinforcement 66 Axial reinforcement 67 Surrounding reinforcement

Claims (2)

A method for constructing a structure consisting of an above-ground structure and an underground structure with a preceding floor as a boundary, comprising:
a ground excavation step of providing an earth retaining wall having a core material and excavating the ground to a depth of a bedding surface;
A foundation framework construction process for constructing a foundation framework on the floor mounting surface;
A subway frame erection process of erecting a steel frame structure composed of columns and beams on the foundation structure;
At the top of the steel frame structure, the preceding floor having an outer periphery beam is constructed around the periphery,
A preliminary floor construction process for joining the retaining wall and the outer perimeter beam via a shear transfer member,
The above-ground structure is constructed using the preceding floor as a work platform, so that the above-ground structure and the underground structure can be constructed in parallel.
The outer periphery beam is provided with main reinforcement, shear reinforcement, and outer periphery reinforcement for reinforcing the periphery of the shear transmission member,
The peripheral reinforcement is
Axial reinforcement arranged parallel to the retaining wall;
The shear transmission member and the surrounding reinforcement are formed in a U-shape to surround at least a part of the shear reinforcement,
A method for constructing a structure, characterized in that the surrounding reinforcement is arranged to connect the shear reinforcement and the shear transfer member in a manner that surrounds the shear transfer member and embraces and surrounds the vertical portion of the shear reinforcement on the retaining wall side and the upper and lower ends connected to the vertical portion . An underground structure constructed inside the retaining wall having a core material;
A structure constructed of a ground structure constructed on the upper part of the underground structure via a preceding floor, and the construction of the ground structure and the underground structure are carried out in parallel,
At the joint between the preceding floor and the retaining wall , a peripheral beam is interposed in which main reinforcement, shear reinforcement, and peripheral reinforcement for reinforcing the periphery of the shear transfer member are arranged,
The joint between the retaining wall and the outer perimeter beam is provided with the shear transfer member and the outer perimeter reinforcement provided in the core material ,
The peripheral reinforcement is
Axial reinforcement arranged parallel to the retaining wall;
The shear transmission member and the surrounding reinforcement are formed in a U-shape to surround at least a part of the shear reinforcement,
A structure characterized in that the surrounding reinforcement is arranged to connect the shear reinforcement and the shear transfer member in a manner that surrounds the shear transfer member and embraces and surrounds the vertical portion of the shear reinforcement on the retaining wall side and the upper and lower ends connected to the vertical portion .