JPH0485419A - Method for constructing underground structure - Google Patents

Abstract

PURPOSE:To improve the accuracy in erection dimensions of a column and improve economic efficiency, productivity and general applicability by the arrangement such that a column and beam made up of ordinary steel framed column or beam for use as a temporary column or beam can be used as permanent ones. CONSTITUTION:A steel framed column 3 is erected, as a core column for pile, in each of a plurality of bores 2 formed inside an earth pressure wall 1 formed in the soil, while jacks 4 provided on the side of the bores are properly extended by remote control. After adjusting the preciseness in erection dimensions of the column 3 by regulating the pressure on the bore wall, foot protection concrete 5 is placed in the lower section of the bore. Thereafter, a steel framed beam 6, which becomes a first stage strut, is connected to the upper part of the column 3, while correcting error in dimensions by means of a connection member 8 and adjustment nut, and excavation is performed to connect a second beam 7 to the column 3. In the similar manner, a third beam 7 and the following beams are connected, while steel frames for floors above ground are erected and after completion of erection of steel frames, underground concrete body is constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of constructing an underground structure such as an underground frame of a building or an underground parking lot.

[Conventional technology]

To construct an underground structure, conventionally, after erecting temporary pillars, a temporary sill or sill is erected, and as the root cutting progresses, this sill is erected in two stages. Gradually increase the number to three stages.

When the underground structure becomes large, reaching five or six levels underground, the number of struts and the amount of temporary materials will naturally increase.

By the way, if the permanent pillars and beams could be used as temporary structures for the above-mentioned mountain retaining, the economic efficiency would be significantly improved, and above ground construction could also be done at the same time, except for the first floor slab, etc., which would shorten the construction period, etc. Productivity also improves significantly.

The following construction method is one of such permanent beam construction methods.

First, the main pillars (steel pipe columns) will be erected during the construction work, and then the steel box beams, which will serve as conventional struts, will be installed.

After this, concrete will be poured inside and a support bridge for the retaining wall will be built horizontally, before moving on to the next excavation work.

Furthermore, we will install the steel frame box on the floor immediately below, and proceed with the construction of the underground frame by repeating internal concrete pouring and excavation.

[Problem to be solved by the invention]

This conventional permanent beam construction method is a special method that uses concrete-filled steel pipe columns and steel box beams, and does not use regular steel columns or steel beams.

If normal steel columns and beams were to be used, first of all, constructing the core columns (pile core columns) would be difficult to construct, and the precision of construction dimensions would be poor (verticality would be slanted).
Therefore, they often cannot be used as permanent steel columns.

In addition, the length of the beam (strut) attached to it will be adjusted at the site, so it cannot be used as a permanent beam.

The purpose of the present invention is to eliminate the disadvantages of the conventional example, and to make it possible to use ordinary steel columns and beams as pillars and beams for permanent installation even when constructing sills for retaining the piles. The object of the present invention is to provide a method for constructing an underground structure that can fully utilize the characteristics of the permanent beam construction method.

[Means to solve the problem]

In order to achieve the above object, the present invention erects pillars underground,
The column/beam frame constructed by erecting a beam at the top of this column is used as a sill beam for retaining the pile, and the second and subsequent beams are erected at the bottom of the column in sequence according to the depth of the root cut. In the construction method of constructing an underground structure, the pillar is a pile core column with an outward pressing means on the side. The construction accuracy was corrected by adjusting the pressure of the means on the hole wall, and concrete was applied to the bottom of the pile core column, and the connection between this pile core column and the main steel beam, which also served as the cut beam, was formed using a male-threaded bolt at one end. Then, use a joining hardware that has a flat plate part with a bolt insertion hole formed at the other end, screw an adjustment nut into the bolt part of this joining hardware, insert the bolt part into the steel column flange, tighten it, and complete the connection. The main idea is that the flat plate part of the hardware is placed over the steel beam flange and tightened with bolts and nuts, and the column flange and beam web are connected with a gusset plate.

[Function] In order to use columns and struts that were conventionally constructed as temporary structures as permanent structures, it is necessary to improve the dimensional accuracy of the pillar construction, and the length of the beams as well as those for permanent structures must be improved. It can be joined to pillars.

According to the present invention, the erecting dimensional accuracy of the pile core column is achieved by easily correcting the inclination of the pile core column in the hole as a reaction by adjusting the pressure of the pressing means provided on the side of the pile core column against the hole wall. It can be made into

Furthermore, the position of the connection of the steel beam to the pile core column can be adjusted by changing the degree of insertion of the bolt into the steel column flange by rotating an adjustment nut that is screwed into a bolt formed at one end of the joining hardware.

Furthermore, since this joining hardware can be attached to the pile core column later, there is no need to provide a protrusion such as a bracket for connecting the pile core column to the steel beam during erection, and there is no need to increase the diameter of the hole.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figures 1 to 4 are side views showing each step of the method for constructing an underground structure according to the present invention. First, as shown in Figure 1, an earth pressure wall 1 is formed in the ground, and this upper pressure wall is Drill hole 2 as necessary inside the area surrounded by 1 using an excavator.

Note that the hole 2 may be created by arranging a steel pipe casing.

Next, a steel column 3 as a pile core column is erected in this hole 1, and as shown in FIG. We have set up JA 7 Ki 4 as a standard.

This jack 4 may be a manual type with a screw structure, but
A hydraulic jack or an air jack may be used, and it should be possible to remotely control the jack from at least near the upper end of the steel column 3.

Before erecting the steel column 3, this jack 4 is shortened so that it does not protrude, and after the steel column 3 is erected in the hole 1, the jack 4 is extended as appropriate by the remote control and the hole wall is tightened. By adjusting the pressure, the inclination of the steel column 3 within the hole 1 is corrected as a reaction.

After correcting the erection accuracy of the steel column 3 in this way, foot protection concrete 5 is placed at the bottom of the steel column 3 as shown in FIG.

Then, a steel beam 6 is joined by adding a joint to the upper end of the steel column 3, and this steel beam 6 becomes a first-stage strut.

Note that this steel beam 6 is the IF floor of a ground-floor building, and the excavation depth is extremely shallow at a location below the ground level, so it is difficult to connect it to the steel column 3 by providing a bracket or forming a joint part. A normal joining method of combing is used.

Next, as shown in FIG. 3, root cutting is performed using the steel beam 6 as a strut for retaining the pile, and a second cut is made according to the depth of the root cutting.
1. As a strut for each step. The steel beam 7 is joined to the steel column 3.

At the same time, construction of the steel frame on the ground floor will also begin.

The steel beam 7 and the steel column 3 are joined using a joining hardware 8 as shown in FIGS. 3 and 4, and as shown in FIGS. The flat plate part 8b has a male threaded bolt part 8a formed at one end and a bolt insertion hole 8C formed at the other end.

The flange 3a of the steel column 3 is formed with an insertion hole through which the bolt portion 8a is inserted. -10. Screw together 10'.

On the other hand, an insertion hole is also formed in the flange 7a of the steel beam 7, and the flat plate portion 8b of the joining hardware 8 is placed over the flange 7a of the steel beam 7 and tightened with bolts and nuts 11.

When such a connection is made, there is still an error in the construction dimensions of the steel column 3, and in order to correct this, it is necessary to rotate the adjustment nut 10 to insert the bolt part 8a of the joint hardware 8 into the steel column flange 3a. This is done by changing the .

At this time, the web 7b of the steel beam 7 and the joining gusset plate 13 formed in advance on the flange 3a of the steel column 3 are joined by the splice plate 12.
The holes 14 for bolting the splice plate 12 of the web 7b are elongated holes.

Further, the holes for bolting provided in the gusset plate may be made long.

As shown in Fig. 4, once the steel beam 7 as the second stage strut has been erected in this way, the roots are cut in the same way, and the third and subsequent stages are cut according to the excavation depth. A steel beam 7 as a beam is similarly erected using joining hardware 8.

In such a connection between the steel column 3 and the steel beam 7, the beam axial force due to the earth pressure acting from the earth pressure wall and the shear force transmitted from the beam to the column are generated by the gusset plate 12 between the steel column 3 and the steel beam 7. In addition, the bending moment of the steel beam 7 is transmitted to the column 3 as a pair of couples at the ends of the beam 7, and in this couple, the tensile force is transmitted via the metal fitting 8 to the bolt portion 8a.
The compressive force is transmitted to the column 3 using one of the nuts screwed together as a reaction force point, and the compressive force is transmitted to the column 3 using the other nut as a reaction force point.

After the erection of the subway frame is completed, the construction of the underground concrete body 15 is carried out.

〔Effect of the invention〕

As described above, the method of constructing an underground structure of the present invention is to use the structure that is used as a temporary structure for retaining a mountain as it is to be used as a pillar for permanent construction.
Since it can also be used as a beam, economic efficiency is improved, and above-ground construction can be carried out at the same time, which improves productivity by shortening the construction period.

In addition, it is possible to use steel columns and beams, which are highly versatile, to use these temporary columns and struts as permanent structures, and it is possible to use columns and beams that were previously not possible. This improves the accuracy of construction dimensions and makes it possible to easily and reliably adjust the connection between columns and beams.

[Brief explanation of drawings]

Figures 1 to 4 show one embodiment of the method for constructing an underground structure according to the present invention, and are side views showing each step, Figure 5 is a side view of the main part, and Figure 6 is a plan view of the same. It is. 1...Earth pressure wall 3...Steel frame column 4...Judge 6.7...Steel beam 7b...Web 8...Joint hardware 8b...Flat plate part 9...-Joint receiver is Hardware 11... Bolt/Nut 13... Gazette Brake 15... Underground Concrete 2... Hole 3a... Flange 5... Foot protection concrete 7a... Flange 8a... Bolt part 8C. ...Bolt insertion hole 10.10'...Adjusting nut 12...Splice plate 14...Long frame Figure 2 Figure 1 3 Figure 4 Figure

Claims (1)

[Claims] The pillar-beam frame is constructed by building pillars underground and installing beams on top of these pillars.The pillar-beam frame is used as a strut for retaining the mountain, and the second stage is installed at the bottom of the pillar depending on the depth of the root cut. In the construction method of constructing an underground structure by erecting the following beams, the pillar is a pile core column with outward pressing means on the side, and this pile core column is used as a steel frame column for permanent installation into the drilled hole. During erection, the accuracy of erection is corrected by adjusting the pressure of the pressing means against the hole wall, and concrete is applied to the lower part of the pile core column, and the connection between this pile core column and the main steel beam, which also serves as the strut, is made using a male screw at one end. Use a joining hardware that has a flat plate part with a bolt hole formed at the other end, screw an adjustment nut onto the bolt part of this joining hardware, and insert the bolt part into the steel column flange. A method for constructing an underground structure, characterized in that the flat plate part of the joining metal is overlaid on a steel beam flange and tightened with bolts and nuts, and the column flange and beam web are connected with a gusset plate.