JPH0759812B2 - Beam construction method for underground floor excavation work - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a basement floor of a building such as a reinforced concrete structure, and in particular, constructing a crossbeam near the ground surface and supporting it. The present invention relates to a construction method of a girder in an excavation work of a basement floor, which is designed to excavate a basement floor.

[Prior Art] When a building is made of reinforced concrete and the construction of the basement is preceded, generally, for excavation work, four retaining walls are turned around, and an abdomen is added to the top. Need to be supported by a beam. At this time, constructing the basement pillar from above the ground first, constructing a cutting beam at the position of the floor on the first floor, excavating roots under the bearing, and excavating downward while countering concrete on the outer wall. The construction method of the basement floor is known, such as the construction method for advancing the construction, the construction method for constructing the outer wall upwards from the bottom after the completion of excavation, and in the construction of a deep basement, the crossbeams are successively re-arranged downward and erected. Excavation is taking place.

It is also well known that steel temporary construction material is used as the cutting beam or that the concrete floor beam of the concrete construction is preceded.Therefore, a pier for the vehicle is installed for root cutting and excavation. Things are also being done.

[Problems to be Solved by the Invention] However, in the conventional beam construction method, if the floor slab on the ground floor is constructed in advance, the opening formed for construction is small, and therefore the excavated earth and sand are carried out and the equipment The efficiency of loading and unloading decreases. Further, when the floor slab is constructed later, the opening can be made large, but a compressive force is applied to the beam member, the cross section of the temporary member becomes large, and it becomes uneconomical as the main member.

Furthermore, when installing the gantry, a slope for the vehicle is required because it will be installed on the top of the floor on the first floor.
A part of the floor surface must be removed and a girder must be erected, and in addition, the workability of reverse-placing the outer wall is poor, and jointing occurs on the wall surface. descend,
There are drawbacks such as.

On the other hand, in the construction of basement columns from the ground, not only the accuracy is limited, but the work of each work type is concentrated at the joint between the basement column and the concrete floor beam, and labor is required in many places. As a result, the workability is unavoidably deteriorated, and the current situation is that such defects are not recognized.

Therefore, the present applicant proposes, based on the above invention, a method of using a cross-shaped joined body having arm portions on all sides when joining a beam of a cut beam to a preceding column (Japanese Patent Application No. 1-98).
No. 546, the title of the invention was "Construction method for basement floors"), but this method had many connection points.

[Means for Solving the Problems] The present invention eliminates the above-mentioned drawbacks, and aims at solving the above problems by improving the construction method of a girder for underground floor excavation work.
Improve the structure of the joint between the preceding basement column and floor beam,
As a result, the construction method for the entire basement floor was invented, and the basement floor beam on the first floor was erected on the ground surface as a beam, and the root excavation was carried out under its support. In the construction method of cut beams for excavation work, the process of forming the cut beams that are the main members in a grid pattern, placing the backfilling member between the cliff wall and the abdomen around the excavation part, and earth pressure by the cut beams. The process of supporting the floor, the process of constructing the floor slab on the lower floor as the excavation progresses, the backfilling member is removed, and the floor slab is constructed on the ground surface using the cutting beam as the permanent beam member, and the mountain retaining wall and the belly. The purpose of the present invention is to provide a method for constructing a girder for excavation work on the basement floor, which includes a step of filling the space between the upright and the uplift. It proposes an improvement. As a result, the construction method of the girder can be installed before the excavation of the floor beam of the main construction, and the construction method at the joint with the concrete construction beam at the top of the basement is improved, It succeeded in rationalizing the formation of the gantry.

[Example] The construction method of the basement floor of the present invention will be described in detail with reference to the drawings showing a preferred example. FIG. 1 is a plan view of a basement floor of a reinforced concrete building adopting the present invention, FIG.
The figure is a sectional view of the basement, Fig. 3 (a), (b),
(C) and (d) are plan views of the beam-column joint body. In the figure, 1 is a reinforced concrete building, 2 is the ground, 3 is the outer wall of the basement of the building 1, 4 is a pile, 5 is the base of the basement, 6 is the pillar of the basement, and 7 is the ground floor. Of the floor beam, 8 is the floor slab, and 9 is the abdomen provided on the top of the outer wall 3.

The pile 4 is cast as a concrete cast-in-place pile to a predetermined depth in the ground 2 that supports the bottom 5, and its top portion 41
The lower end portion 62 of the steel core pillar 61 of the pillar 6 is embedded and connected to the pillar 6, and the pillar 6 is made of reinforced concrete.

A bracket 32 is provided on the top portion 31 of the outer wall 3, and an outer peripheral bulge 9 is supported on the upper surface of the bracket 32, and the bulge 9 has a steel frame 91 inside. Here, the floor beam 7, which is a member to be erected on the uprising 9, has an intermediate portion formed as a precast concrete (hereinafter referred to as PC) beam 71, and steel connecting members 72 are provided at the base ends at both ends thereof. The parts are embedded and projected, and are connected to the gussets 92 provided at predetermined intervals on the steel frame 91. A connecting portion 74 is formed at the connecting portion by a connecting means formed by the side surface of the bulging member 9 and the connecting reinforcing bar 73 (see FIG. 5) protruding from the end of the PC beam 71.

Between the uprising 9 and the outer wall 3, a concrete extension 81 of the floor slab 8 is filled along the outer wall 3.

Next, inside the outer wall 3, a bracket 64 is fixed to the top portion 63 of the core column 61, which is the second feature of the present invention.
The beam-column joint body 10 of the column 6 and the PC beam 71 is placed, and the beam-column joint body 10 and the PC beam 71 are joined to form the floor beam 7 as a whole. The floor beam 7 is a permanent beam. At the same time, it regains its position and forms a beam for 9.

Next, as shown in FIG. 3 (a), the beam-column jointed body 10 is, as a preferred embodiment, generally in the shape of "knee" for the length of the bridges 6 and 6 which are adjacent to each other as a whole. PC molded into
It is a joined structure made up of a central beam main body 11 and bulged portions 12, 12 at both ends. The bulged portion 12 is made of a plurality of steels as shown in FIGS. 4 and 5. The arm portion 13 is provided, the base end thereof is embedded and fixed, and the tip end is projected so as to correspond to the PC beam 71 intersecting at the column 6. The enlarged portion 12 is not limited to the shape described above, and may be a modified example of FIG. 3 (b).

At the center of the enlarging parts 12, 12 on both ends of the beam-column joint 10,
The through hole 14 for loosely fitting and inserting 61 is formed and the through hole is formed.
A plurality of sleeves 15 for inserting reinforcing bars for joining the upper and lower pillars 6 are embedded around 14 and are supported by the bracket 64 around the through hole 14.

The beam-column joint body 10 and the PC beam 71 portion are formed lower than the floor surface by the thickness of the floor slab 8, and the connecting member 72 of the PC beam 71 and the arm portion 13 of the beam-column joint body 10 have a steel structure. Being combined,
At the joint part, a joint part 74 made of concrete cast integrally with the concrete of the floor slab 8 including the beam.
Connected by.

In this way, the floor beam 7 of the permanent installation is formed, and after it has a function as a cutting beam for the uprising 9, the concrete column 65 is placed around the core column 61 to form the column beam. 6 is completed. At this time, the upper portion of the reinforcing bar 66 of the pillar 6 is connected to the reinforcing bar of the pillar 6 on the upper floor via the sleeve 15.

The top portion 63 of the steel core pillar 61 inserted into the through hole 14 is a through hole.
Since it is loosely fitted inside 14, it is installed with sufficient accuracy to the beam-column joint body 10 and is integrally connected by the concrete 65 of the pillar 6 and the concrete of the floor slab 8.

The beam-column joint body 10 of the present invention may have a configuration other than the above, and as another embodiment, as shown in FIG. 3 (c), the enlarged portion 12 of the beam-column joint body 10 is provided only at the center thereof. In addition, the beam-column joint body 20 can be provided in which the through hole 14 that engages with the core column 61 is provided in the central portion thereof. Other configurations are the same as those of the beam-column jointed body 10, and the connecting means 72 similar to the general PC beam 71 is formed at both end portions 21 and 21 located at the center of the span of the column 6 to connect the adjacent columns 6. It is used in connection with the same column-beam joint body 20 that is worn.

Further, as still another embodiment, as shown in FIG. 3 (d), the enlarged portion 12 of the beam-column joint body 10 has only one end portion thereof, and the core column 61 is attached to the center portion thereof. The beam-column joined body 30 having the through holes 14 can be provided. The joint member 72 of the other end 31 of the beam-column joint body 30 is also similar to the above, and for example, the column-beam joint body 10 is extended with the other end portion 31 facing the pillar 6 on which the beam-column joint body 10 is installed. And can be applied to a number of consecutive spans.

Furthermore, for example, in order to join an arbitrary floor beam 7 to an arbitrary column 6 located in an irregular portion of the building 1, a single unit without a beam main body 11 of a beam-column jointed body 10 is made according to the enlarging section 12. It is possible to use a joined body which is formed and has arm portions 13 on all four sides to have a cross shape. For such a single joined body,
Reference can be made to the proposals relating to the previous application.

It goes without saying that the construction method of the basement floor of the present invention is not limited to the above-mentioned embodiment. For example, the general floor beam 7 connected to the beam-column joint body 10 or the like is not limited to the PC beam and is made of steel. It may be a beam. Further, the pile 4 is a steel pile, a PC pile, if it is buried in advance by connecting the lower end portion 62 of the core column 61 to the top portion 41 thereof.
It can be replaced with piles, etc.
The joining means with the PC beam 71 is not limited to the steel plate connecting member 72, and a normal connecting method using anchors as reinforcing bars can be adopted.

[Operation] Since the construction method of the girder of the present invention is to form the basement having the above-mentioned configuration, the construction adopts the present invention in the abdomen portion of the usual construction method, It can be easily carried out by applying the beam-column joint body of the present invention alone or in combination to the beam portion. The operation of the present invention thus configured will be described in the order of construction steps based on FIGS. 1 and 2. In the figure, first, the uppermost part of the outer wall 3 is constructed on the ground, and the inner wall of the outer wall 3 is laid up to construct the agitation 9. Then, a backfilling member 40 formed of I-shaped steel or a PC block or the like between the outer wall 3 and the bulging member 40.
Are intervened at predetermined intervals.

On the other hand, the cast-in-place concrete pile 4 is driven to a predetermined depth, and the lower end portion 62 of the steel core column 61 is inserted and connected to the top portion 41 thereof before the hardening thereof sufficiently progresses.

Next, the beam-column jointed body 10 or the like separately shaped by the prefab is inserted from the top portion 63 of the core column 61 at the position of the through hole 14, so that the beam-column joined body 10 or the like is stably placed on the bracket 64. It is supported and the construction of the concrete 65 of the pillar 6 below it is possible. When the depth of the basement is deep, a plurality of pillar-beam joints 10 and the like are prepared by inserting them according to the number of steps of the girder (the number of floors under the ground), and the brackets 64 on each floor are naturally attached later.

On the other hand, the PC beam 71 is arranged between the arm portion 13 of the beam-column joint body 10 and the like and the uprising 9, and the end portions thereof are connected by the joining member 72 to complete the floor beam 7 and the floor beam 7. The connection part of the beam 7 and the concrete of the floor slab 8 are cast, and a part of the concrete can be used as a gantry S for vehicle entry. At that time, if an opening for excavation is provided in a part thereof, excavation work in the next step becomes possible.

Before the concrete placing of the floor slab 8, preferably when the floor slab 8 on the first basement floor is formed, deformation of the mountain retaining wall is prevented by the underground structure, and the backfilling member 40 is removed,
The concrete extension 81 of the floor slab 8 is filled between the outer wall 3 and the waving 9, and the axial force of compression of the girder is released,
The floor beam 7 can act as an integrated beam.

The construction method of the outer wall 3 accompanying the excavation is arbitrary, and usually, the reverse construction method is adopted under the support of the permanent floor beam 7, and the installation of multi-level girders associated with the excavation is also used for root cutting and excavation. The accompanying carry-out of sand and sand can also be carried out by the usual construction method using the opening provided in the floor slab 8.

Here, in the present invention, since the beam-column joint body 10 and the like are configured as described above, it is extremely easy to mount the applied core column 61 on the top portion, and moreover, by the through hole 14. Since the column 6 and the floor beam 7 can be fixed after securing the joining accuracy, the axial force of the cutting beam is safely transmitted,
No detailed structure such as gussets is required.

[Effects of the Invention] In the construction method of the underground floor of the present invention, the basement floor excavation in which the first floor permanent floor beam is erected on the underground surface to form a cut beam and root excavation is performed under the support of the beam In the construction method of construction beam
The process of forming the trusses that will be the main members in a grid pattern, the process of supporting the earth pressure by the trusses by arranging the backfilling member between the cliff wall around the excavation part and the abdomen, and the progress of excavation Along with this, the process of constructing the floor slab on the lower floor, the process of removing the backfilling member, constructing the floor slab on the ground surface using the cutting beam as the permanent beam member, and filling the space between the mountain retaining wall and the abdomen. Therefore, by arranging a column-beam joint body in which a joint between a pile or a column and a girder using a permanent floor beam is formed in advance, it is possible to simplify the construction work with a complicated structure. Moreover, not only can it be formed with high accuracy, and the members of the main installation can be used reasonably, but the cost required for constructing the gantry can be reduced. In addition, for the beam-column joint, it is possible to use members formed in accordance with the basic plan of the building, and although PC members are used, not only is there a high degree of freedom in design, Is smoothly transmitted and accuracy is ensured, and particularly in a beam-column joint body having through holes at both ends, the effect of reducing the number of joints is great.

Therefore, in the present invention, prior to excavation excavation that is indispensable for the construction of the basement, while the floor beam of the main construction is used as the cutting beam, the rational connection between the pile, the pillar and the cutting beam is secured. In particular, the adoption of PC members can greatly contribute to the reduction of labor cost and construction period, and can be applied to the construction method of the basement floor to solve the problem.

[Brief description of drawings]

The drawings are for explaining the construction method of the basement floor of the present invention based on examples. FIG. 1 is a plan view of the basement floor portion of a reinforced concrete building adopting the present invention, and FIG. 2 is the basement portion thereof. 3A to 3D are plan views of a beam-column joint body used in the method of the present invention, FIG. 4 is an enlarged plan view of a main part, and FIG. It is a vertical sectional view of a connection part. 1 ... Building, 2 ... Ground, 3 ... Exterior wall, 4 ... Pile, 5
…… Bottom plate, 6 …… Pillars, 7 …… Floor beams, 8 …… Floor slabs, 9
…… Agitated, 10, 20, 30 …… Column-beam connection, 11 …… Beam body, 12 …… Enlarged part, 13 …… Arm, 14 …… Through hole, 15
...... Sleeve, 40 …… Back filling material, 41 …… Top, 61 ……
Core column, 62 ... Lower end, 63 ... Top, 64 ... Bracket,
65 …… Concrete, 66 …… Reinforcing bar, 71 …… PC beam, 72 ……
Joining member, 73 …… Reinforcing bar, 74 …… Connection concrete,
81 …… extension part, 91 …… steel frame, 92 …… gusset, S …… stand.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yutaka Saito 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Yukino Kurose 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Yoichi Seki 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Nobuhiro Okuyama 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Ken Incorporated Co., Ltd. (72) Inventor Shigeki Otsuka 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu Ken Incorporated (72) Inventor Haruhiko Mazume 2-16-1, Kyobashi, Chuo-ku, Tokyo Shimizu-ken Inside the corporation

Claims (3)

[Claims] 1. A cut beam construction method for a basement floor excavation work, in which a floor beam on the first floor is erected to form a cut beam, and root cutting is performed under the support of the floor beam. A step of forming a cut beam to be a member in a lattice shape, a step of arranging a backfilling member between the mountain stop wall around the excavation part and the abdomen to support earth pressure by the cut beam, as the excavation progresses, Includes the steps of constructing the floor slab on the lower floor, removing the backfilling member, constructing the floor slab on the ground surface using the cutting beam as the main beam member, and filling the space between the mountain retaining wall and the abdomen. A beam construction method for underground floor excavation. 2. A cutting beam to be a permanent floor beam for the first floor, which is provided on the ground surface, is a step of placing a core pillar of a pillar on the basement floor in the ground in advance, and a precast having a through hole at the top of the core pillar. It is formed by the process of loosely fitting a concrete beam-column joint and inserting it to attach it, the process of connecting a beam such as precast concrete to the beam-column joint, and the process of post-casting concrete on a steel column. The method for constructing a girder for underground floor excavation work according to claim 1. 3. The excavation work for the underground floor according to claim 2, wherein a gantry is formed by the basement pillar, the permanent floor beam on the first floor, and the slab, and the gantry is used for excavation work. Beam construction method.