JP3882536B2 - Reconstruction method for existing buildings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rebuilding method for an existing building, and more particularly, to a rebuilding method suitable for a case where an existing building has an underground floor.
[0002]
[Prior art]
Buildings such as urban areas often have an underground floor in order to effectively use the underground space. And when rebuilding an existing building with a basement floor, it is normal for a renovated building to be planned with a basement floor. Conventionally, in such a rebuilding of a building with an underground floor, the underground frame of the existing building has been completely removed without being reused.
[0003]
[Problems to be solved by the invention]
However, it is desirable to reuse the existing building frame as effectively as possible in order to reduce the waste materials generated by the rebuilding work and to reduce the cost of the work.
[0004]
Also, if the existing building has a large number of underground floors (for example, 2 or more underground floors), the water pressure and earth pressure on the underground outer walls will increase. It is necessary to proceed with the construction. Therefore, for the underground part, the dismantling of the existing building and the construction of the renovated building must be performed alternately, resulting in a long construction period.
[0005]
This invention is made | formed in view of said point, and it aims at providing the rebuilding construction method which can perform the rebuilding construction of the existing building which has a basement floor in a short construction period at low cost.
[0006]
[Means for Solving the Problems]
The purpose of the above-mentioned object is to arrange the floor concrete by placing a pair of steel plates above and below the floor concrete in the basement floor of an existing building and placing mortar or concrete between the upper and lower steel plates. The basement floor of the renovated building will be reinforced, and the basement floor column made of steel or CFT columns will be installed, and the basement column and the pair of steel plates will be welded together to form the basement structure. It is also achieved by the rebuilding method characterized by this.
The floor concrete may include a notch in the vicinity of the basement pillar, and a stud may be attached to the outer periphery of the basement pillar.
[0007]
According to the present invention, since the basement floor of the existing building is reinforced and used as the basement floor beam of the renovated building, disassembly of the basement of the existing building becomes unnecessary. For this reason, the construction period of the rebuilding work can be shortened, and the amount of waste material generated in the rebuilding work can be reduced. In addition, since the underground structure of the existing building can be used effectively, the amount of materials required for rebuilding can be reduced to reduce the construction cost.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Drawing 1 (a)-(e) is a figure for explaining the whole construction procedure in the rebuilding method of the existing building which is one embodiment of the present invention. FIG. 1A shows a front view of an existing building 10 before dismantling. As shown in the figure, the existing building 10 is a building with an underground floor having a ground frame 11 and an underground frame 12.
[0009]
When rebuilding the existing building 10, first, as shown in FIG. 1 (b), the ground frame 11 of the existing building 10 (including the 1st floor beam, 1st floor, 1st basement column, 1st basement wall) The work floor 14 is built at the ground level by dismantling and removal. Then, with construction machines 16 and 17 installed on the work floor 14, mountain retaining work such as construction of the support frame 18 is performed, and pile ground work such as excavation of a hole 19 for the pile is performed. In that case, the interference part of the underground frame 12 of the existing building 10 is removed beforehand.
[0010]
Next, as shown in FIG. 1 (c), after the underground column 20 which is a steel column or CFT (steel pipe concrete structure) column is built, the first floor beam steel frame of the renovated building is built and the floor concrete 22 is struck. Set up. Then, after the work floor 14 is removed and the strength of the floor concrete 22 is expressed and can be used as a work floor, as shown in FIG. The construction of the frame 12 is performed in parallel. In the construction of the underground skeleton 12, the floor concrete 30 of the underground skeleton 12 is reinforced, construction is performed to use the concrete as a beam of the renovated building, and the built-in underground pillar 20 is coupled.
[0011]
2-4 is a figure for demonstrating the reinforcement construction of the floor concrete 30. FIG. 2 and 3 are cross-sectional views showing the floor concrete 30 before and after reinforcement, respectively, and FIG. 4 is a cross-sectional view taken along the line IV-IV shown in FIG.
[0012]
As can be seen from FIGS. 2 to 4, when reinforcing the floor concrete 30, first, a part of the beam 32 of the underground frame 12 is removed as necessary to reduce the size of the beam. As the beam length of the beam 32 is reduced, the beam height of the beam constructed by reinforcement of the floor concrete 30 is reduced accordingly, and a large effective underground height can be secured. In addition, since the underground outer peripheral wall functions as a seismic wall in the underground frame 12, the horizontal force shared by the ramen structure part composed of columns and beams is relatively small, and the necessary bending rigidity is a reinforcement part described later. Since the width (that is, the width of the composite beam to be constructed) W can be appropriately set, there is no problem in strength even if the beam is reduced.
[0013]
Next, the bevel bars 34 are driven into the lower surface of the floor concrete 30, and the roughening 36 and the shear cotter 38 are applied to the upper and lower surfaces of the floor concrete 30 by a water jet. The concrete 42 is placed between the floor concrete 30 and the steel plate 40 in a state where the steel plate 40 is held at a predetermined position below the floor concrete 30. Further, the steel plate 44 is held above the floor concrete 30 with a slight gap, and the mortar 46 is filled in the gap to join the steel plate 44 to the floor concrete 30. The width W of the steel plates 40 and 44 shown in FIG. 4 is the width of the reinforcing portion.
[0014]
Through the above construction, the floor concrete 30 is reinforced, and the composite beam 50 composed of the floor concrete 30, the cast concrete 42, and the steel plates 40 and 44 is constructed. Note that, as described above, the floor concrete 30 is provided with the gibber bars 34, the roughening 36, and the shear cotter 38, so that the floor concrete 30, the placing concrete 42, and the mortar 46 are firmly integrated. In addition, the steel plates 40 and 44 can be firmly integrated with the concrete portion and the steel plates 40 and 44 by using a steel plate provided with a shear cotter, a gibber bar, a stud gibber, and the like. Overall integrity can be ensured.
[0015]
Thus, the composite beam 50 made of steel plate and concrete is constructed by reinforcing the floor concrete 30 of the underground frame 12 of the existing building 10, and this composite beam 50 is used as a structural beam in the underground part of the renovated building. As described above, if the beam length of the beam 32 of the underground frame 12 is reduced, the beam length of the composite beam 50 can be reduced accordingly, thereby increasing the effective floor height of the basement floor of the renovated building. Can do.
[0016]
FIG. 5 shows another example of the reinforcing structure of the floor concrete 30, and is a cross-sectional view corresponding to FIG. In the reinforcing structure shown in FIG. 5, after removing the reinforcement target portion of the floor concrete 30, a shear reinforcing bar 100 is arranged in the removed portion, and the concrete 102 is placed between the steel plates 44 and 40 arranged above and below the reinforcing reinforcement 100. This ensures a greater shear strength. In addition, it is possible to use various reinforcing structures such as reinforcing the floor concrete 30 only with H-shaped steel without using concrete, or reinforcing only with concrete without using a steel plate.
[0017]
6 is a perspective view showing a coupling structure of the composite beam 50 and the built-in underground pillar 20, and FIG. 7 is a vertical sectional view thereof. 6 and 7 show the case where the underground column 20 is an outer diaphragm column, and the upper and lower steel plates 44 and 40 of the beam 50 are directly welded to the outer periphery of the steel pipe of the underground column 20. In addition, at the connection portion with the underground pillar 20, a notch 52 is provided in the floor concrete 30, and a concrete 42 is placed by attaching a gibber stud 54 to the outer periphery of the underground pillar 20, so that the concrete 42 and the underground pillar 20 Ensures unity. In addition, when the underground pillar 20 is an inner diaphragm type | mold, the steel plates 44 and 40 will be welded to the same level position as an inner diaphragm of the outer peripheral surface of the underground pillar 20. FIG. In addition, through diaphragm type (the underground pillar 20 is cut at the position of the steel plates 44, 40, a diaphragm larger than the outer diameter of the underground pillar 20 is inserted into the cut portion, and the steel plates 44, 40 and the underground pillar 20 are inserted into the diaphragm. It is also possible to use a method of welding the cut surfaces of
[0018]
In this way, by connecting the composite beam 50 to the underground column 20 that is a steel column or CFT column, the bending stress of the composite beam 50 is transmitted to the ground via the underground column 20, thereby 50 can function as a structural beam in the underground part.
[0019]
Returning to FIG. 1 again, in the construction of the underground frame 12 shown in FIG. 1 (d), the construction of the composite beam 50 by the reinforcement of the floor concrete 30 and the construction of the connection with the underground pillar 20 are directed downward for each underground floor. Repeat sequentially. In addition, about the underground frame 60 of the extension part deeper than the underground frame 12 of the existing building 10, construction is advanced by the normal reverse driving method. At that time, if the underground work of the underground structure 12 of the existing building 10 is a direct business, wait for the strength of the composite beam 50 to develop so that the weight of the underground structure 12 can be transmitted to the striking strut. Start the excavation work using the reverse hammering method.
[0020]
When the strength of the underground structure 60 of the extension portion is developed, thereafter, as shown in FIG. 1 (e), the temporary construction is started from the portion where the construction of the ground portion 24 and the underground structure 12 is completed without waiting for the completion of the extension structure. It can be used.
[0021]
As described above, according to the present embodiment, in the rebuilding work of the existing building 10, it is possible to use it as a part of the basement of the renovated building without dismantling the basement 12 of the existing building 10. Become. For this reason, it is possible to reduce the amount of waste materials generated in rebuilding work, shorten the construction period of rebuilding work, and realize cost reduction by reducing the amount of materials required for rebuilding work. You can also.
[0022]
In addition, if there is an underground extension part, temporary use can be started in a part of the renovated building without waiting for completion of the construction of the extension part, so the construction period can be further shortened substantially. it can.
[0023]
【The invention's effect】
As described above, according to the present invention, the basement floor of the existing building is reinforced to form the basement floor beam of the renovated building, so that it is not necessary to dismantle the basement of the existing building. For this reason, the construction period of the rebuilding work can be shortened, and the amount of waste material generated in the rebuilding work can be reduced. In addition, since the underground structure of the existing building can be effectively used as the structure of the renovated building, it is possible to reduce the amount of materials necessary for rebuilding and to reduce the construction cost.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a construction procedure in a rebuilding method according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing floor concrete of an existing underground skeleton.
3 is a cross-sectional view showing a composite beam obtained by reinforcing the floor concrete of FIG.
4 is a cross-sectional view taken along the line IV-IV in FIG. 3;
FIG. 5 is a cross-sectional view showing another reinforcing structure for floor concrete.
FIG. 6 is a perspective view showing a coupling structure of a composite beam and an underground column.
7 is a vertical sectional view of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Existing building 12 Underground frame 20 Underground pillar 30 Floor concrete 40,44 Steel plate 42 Concrete 50 Composite beam

Claims (2)

A pair of steel plates are placed above and below the floor concrete in the basement floor of the existing building, and the floor concrete is reinforced by placing mortar or concrete between the top and bottom steel plates to form a basement floor beam in the renovated building. ,
A rebuilding method for an existing building , wherein a basement column comprising a steel column or a CFT column is built in and the basement column and the pair of steel plates are welded to form an underground structure . 2. The rebuilding method for an existing building according to claim 1, wherein a notch portion is provided in the vicinity of the basement pillar of the floor concrete, and a stud is attached to a portion of the basement floor that contacts the notch portion. Reconstruction method for existing buildings.

Images