JPH02210120A - Underground beam structure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of underground beams in buildings, and particularly relates to the structure at the joints of underground beams when the pillars of the building are made of steel. It is something.

[Prior art] Underground beams in main bridges of buildings are installed between column bases and are important members for handling column base moments, but because they are entirely underground, they are generally not constructed of reinforced concrete. It is often poured at the same time as the foundation concrete. Generally, in known foundation structures, reinforced concrete work for the foundation and underground beams is first performed, and columns are erected on the foundation after the concrete has hardened. In addition, when underground beams are placed around the base and bear the support pressure on the underside of the base, their size increases, and many temporary materials are required for reinforcing reinforcing bars and subsequent concrete pouring work. and construction labor.

On the other hand, in recent years in the construction industry, construction periods have tended to be shortened, and structural frames are increasingly constructed of steel frames. On the other hand, the labor situation is worsening, and it is particularly difficult to secure formwork carpenters and reinforcing bar workers at construction sites.

[Issues to be solved by the invention] In the conventional construction method for underground beams, since the underground beams are made of reinforced concrete, they are constructed at the same time as the reinforced concrete of the foundation, and then the columns are erected. It is necessary to wait for the anchor bolt to harden, and moreover, a great deal of consideration is required for accurate installation of the anchor bolt. Furthermore, fixing the reinforcing bars of the underground beams at the column bases becomes complicated.

On the other hand, if the underground beams are large, appropriate reinforced scaffolding will be used. In addition, when constructing it, the concrete formwork work requires a completely different process, and each type of construction requires the labor of skilled workers to remove materials and the frame, and the construction period. Although underground beams have a very ordinary structure, they have not received much attention, and their solution has been an issue.

[Means for Solving the Problems] The present invention was devised to solve the above-mentioned problems, and consists of installing steel columns at the upper ends of foundation piles, The underground beam to be erected is formed of precast concrete, and steel connecting members are buried at both ends of the underground beam with the connecting parts protruding, and are directly rigidly connected to the steel column. The purpose of this project is to provide a structure for underground beams. According to this invention, when constructing an underground beam, the underground beam is formed in advance from precast concrete and is directly erected between the steel column bases via the connecting member of the steel frame installed at the end. This has succeeded in shortening the manufacturing process for the underground beam itself, eliminating the need for temporary construction of reinforced scaffolding and formwork, reducing on-site labor, and significantly shortening the construction period for reinforced concrete.

[Example] The structure of the underground beam of the present invention will be explained in detail based on the drawings of the example. Fig. 1 is a plan view of a part of the building, Fig. 2 is a cross-sectional view of the frame for one span of a column, and Fig. 3 is a perspective view of the column base. In the figure, 1 is a steel frame column, 2 is its foundation,
3 is an underground beam that fixes the legs of column 1, 4 is a bottom plate, and 5 is
is a foundation pile that supports the lower surface of foundation 2.

The underground beam 3 is manufactured as a precast reinforced concrete member at an appropriate precast concrete factory, and a steel frame serving as a connecting member 31 is attached to both ends of the beam 3, and the connecting end 32 is made to protrude to a predetermined length. Ru. The connecting member 31 has stud bolts 34 planted on the upper and lower surfaces of the base end portion 33, and is buried in concrete with the end portion 32 protruding as a connecting portion when the underground beam 3 is manufactured. 3
5 is the main reinforcement at the top and bottom of the underground beam 3, and the connecting members 31 at both ends
A precast concrete beam is formed by supporting the flange 36 of the beam and attaching an ordinary stirrup 37 thereto.

On the other hand, the column 1 is erected on the foundation pile 5, and a connecting flange 12 is fixed to the periphery of the column base 11, and its position is in line with the flange 36 of the connecting member 31 of the underground beam 3. The underground beam 3 is constructed under the column 1 by connecting the flange 12 and the connecting member 31 according to the position.

[Function] The function of the underground beam structure of the present invention will be explained in detail based on the construction process of an embodiment shown in the drawings. In FIG. 2, first, the foundation pile 5 is constructed, and the base plate 13, which is normally attached to the column 1, is placed on the top surface of the foundation pile 5, and is fixed with the anchor bolt 14 installed in the foundation pile 5. will be erected.

At this point, the reinforcing bars of the foundation 2 may be arranged, and the footing 21 portion of the foundation 2 excluding the connection portion between the column base 11 and the underground beam 3 may be constructed.

On the other hand, the above-mentioned underground beam 3 is manufactured at a concrete factory, transported to the construction site, and the column base 1 of the column 1 is
It will be constructed between 1 and 2. In this construction, the end 32 of the connecting member 31 protruding from the end of the underground beam 3 is used as a connecting part, and is rigidly connected by welding to the connecting flange 12 of the column 1.
Column 1 and underground beam 3 are directly connected. Next, the whole of Basic 2.

Alternatively, post-cast concrete 22 is poured in the excluded part of the footing 21 to construct the foundation 2, and the column base 11 and the foundation 2 are
and integrate them. Through this work, the underground beam 3 is fixed to the column base 11 of the column 1, and the frame of the column 1 and the underground beam 3 is completed. Therefore, erecting the column 1 using the anchor bolt 14 not only shortens the construction period in advance of reinforced concrete construction, but also improves the degree of fixation of the column 1 and improves the stability of the column base.
1. Various steel materials on the upper and lower sides are saved.

[Effects of the Invention] The present invention erects a steel frame column at the upper end of the foundation pile, forms an underground beam constructed from precast concrete at the lower end thereof, and installs steel frames at both ends of the underground beam. First of all, it is made by burying the connecting member made of steel with the connecting part protruding and directly rigidly joining it to the steel column.

Even if the underground beam is quite large, it can be produced labor-savingly as a precast concrete beam, and the construction period required for its production can be significantly reduced.Moreover, installation at the construction site is much easier than with ready-made members. Because it is a connection, the construction period is shortened. In addition, the steel frame of the column and the underground beam are directly and rigidly connected by welding the steel connection member and the steel column, and the stability of the column base is sufficiently ensured by the simple structure. Since it is constructed before the reinforced concrete construction, the construction period is shortened without being affected by the hardening of the concrete. Furthermore, it is integrated with the foundation using post-cast concrete.

This invention should be said to have a revolutionary effect on improving underground beam construction methods, as it does not require special fixing means and can be constructed at low cost.

[Brief explanation of the drawing]

The drawings are drawings showing an example in which the underground beam construction method of the present invention is adopted, in which Fig. 1 is a floor plan showing a part of the building, and Fig. 2 is an elevation view of one column span. FIG. 3 is a perspective view of the column base. 1...Column, 2...Foundation, 3...Underground beam, 4...
Bottom plate, 5... Foundation pile, 11... Column base, 12...
Flange, 13... Base plate, 14... Anchor bolt, 21... Footing, 22... Post-cast concrete, 31... Connection member, 32... End, connection part, 33...・Base end, 34... Stud bolt, 35... Main reinforcement, 36... Flange, 37...
Stirrup. Figure 1 Figure 2

Claims (1)

[Claims] A steel column is erected at the upper end of the foundation pile, and an underground beam erected at the lower end is made of precast concrete.
An underground beam structure characterized in that steel frame connecting members are buried at both ends of the underground beam with their connecting parts protruding, and are directly and rigidly connected to a steel column.