JPH08158341A - Joining structure of pile and beam - Google Patents

Abstract

PURPOSE: To facilitate the connection of a pile and a beam and shorten the construction period of a structure. CONSTITUTION: A receive base 15 composed of a support member 16 and a receiving metal tool 18 is installed at the head of a pile 5 and a precast concrete joint form 25 is placed on the receiving metal tool 18. The end of a beam form 8 is placed on the joint form 25. And reinforcements are arranged in the joint form 25 and the beam form 8 and then concrete is placed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for joining a pile and a beam, which is suitable for use in constructing a structure such as a jetty, and a method for constructing a structure using the same.

[0002]

2. Description of the Related Art As is well known, a structure such as a jetty has a structure in which a pile head and a beam are rigidly connected to each other and a floor is formed on the upper surface thereof. Conventionally, steel frames and steel pipes are often used for piles of such structures, and reinforced concrete structures and steel frame reinforced concrete structures are often used for beams. When constructing such a structure, first, a pile is erected at a predetermined position. Next, after constructing a steel frame and arranging reinforcing bars between these adjacent piles, a beam is formed by assembling a formwork and injecting concrete here.

[0003]

However, the above-described conventional joint structure between piles and beams and the method for constructing a structure using the same have the following problems.
First, needless to say, it takes time to construct the joint between the pile and the beam. In addition to this, when the beam is formed of cast-in-place concrete, the formwork must be assembled and dismantled, and work scaffolding and support work must be installed to perform these works. It is difficult to shorten the construction period of the structure because these works take a lot of time and labor.

In particular, when the structure to be constructed is a pier installed on the sea or the like, each of the above problems becomes more remarkable because the construction work is performed on the sea surface. Since the support work and the scaffolding must be installed in the sea, the time required for the assembling / disassembling work is limited due to the influence of the tide level, which causes a problem that the progress of the construction is hindered. Moreover, work on the sea surface is greatly affected not only by the weather but also by the sea conditions, and the waves may damage the support work, scaffolding, and formwork.

The present invention has been made in consideration of the above points, and a pile and a beam that can facilitate the connection between the pile and the beam and shorten the construction work period of the structure. It is an object of the present invention to provide a joint structure of and a construction method of a structure using the same.

[0006]

The invention according to claim 1 is
A joint structure of a pile head and a beam, wherein the pile head has a ring-shaped receiving member through which the pile is inserted, and the receiving member is hung on the pile and hangs the receiving member. A pedestal consisting of a support member is provided, and a precast concrete molding formwork that forms a connection between the pile and the beam is installed on the receiving member of the pedestal, and Is characterized in that the end portion of the beam is placed and the inside thereof is filled with concrete.

According to a second aspect of the present invention, when constructing a structure, after a pile is erected at a predetermined position, a pedestal including a ring-shaped receiving member and a supporting member for suspending the receiving member is provided. The pile is inserted into the receiving member and the support member is placed on the pile to attach the pile to the head of the pile, and then the pile-beam connecting portion is formed on the receiving member. A precast concrete joint formwork is installed for placing the precast concrete beam formwork on the joint formwork, and then reinforcing bars are arranged in the joint formwork and the beam formwork. The feature is that the concrete is poured and filled.

According to a third aspect of the present invention, in the method for constructing a structure according to the second aspect, after the concrete is poured into the joint form and the beam form, the floor of the structure is removed. The feature is that it was constructed.

The invention according to claim 4 is the invention according to claim 2 or 3.
In the method of constructing a structure as described above, a temporary scaffold is integrally attached to a support member of the pedestal in advance.

[0010]

According to the first aspect of the present invention, the precast concrete joint formwork is installed on the receiving member of the pedestal installed on the head of the pile, and the end of the beam is mounted on the joint formwork. It was placed and the concrete was filled in the joint form. As a result, the head of the pile and the beam are joined via the pedestal and the concrete. In addition, since the precast concrete joint formwork is installed on the pedestal provided on the head of the pile, it is necessary to support the joint formwork when constructing the joint part between the pile and the beam. No support work is required.
Further, when the beam is erected, since the end portion of the beam is simply placed on the pedestal, the beam erection work can be easily performed. Furthermore, since the pile and the beam are joined via the pedestal provided on the pile, the pedestal can absorb the build-up error in the vertical direction of the pile and the rotation direction around the axis.

According to the second aspect of the invention, after the pile is erected at a predetermined position, the pedestal is attached to the head of the pile, and then the connection form is set on the receiving member of the pedestal. The beam formwork is placed on this joint formwork, and the reinforcing bar is reinforced inside the joint formwork and the beam formwork, and concrete is poured and filled. At this time, since the connection form and the beam form were made of precast concrete, the work such as assembling and disassembling the form, the supporting work and the work scaffolding for performing these works became unnecessary, and the pile and the beam were It can be easily integrated. Further, when the beam is erected, since the end portion of the beam is simply placed on the pedestal, the beam erection work can be easily performed. Furthermore, by mounting the pedestal on the head after the pile is erected, the mounting error in the vertical direction of the pile and the rotation direction around the axis can be absorbed, and the pedestal can be mounted with high accuracy. it can.

According to the third aspect of the invention, the floor is constructed after the concrete is poured into the joint form and the beam form. This will allow you to
The pile and the beam can be integrated. Moreover, when concrete is poured, the upper surfaces of the beam and the joint are substantially flat.

According to the fourth aspect of the invention, the temporary scaffold is integrally attached to the support member of the pedestal in advance. This eliminates the need to install a scaffold on the ground or in the sea even when performing work such as installation and position adjustment of the receiving member of the pedestal.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings. Here, an example will be described in which the joint structure of a pile and a beam according to the present invention and the method of constructing a structure using the same are applied to a jetty installed in a harbor or the like. As shown in FIGS. 1A and 1B, the jetty (structure) 1 is provided so as to project from the land 2 side toward the sea 3 side.

The pier 1 is installed between the piles 5 standing upright in the sea 3 at predetermined intervals and the piles 5 and 5 adjacent to each other, and the beams 6 and 6 are arranged in a grid pattern in a plan view. ,, and beam 6,
6, ... and a floor 7 formed above.

As shown in FIG. 1 (b), the pile 5 is made of a cylindrical steel pipe, and a fixed length of the lower end is driven into the seabed ground (not shown), and the upper end thereof projects above the water surface. Has a length that

As shown in FIG. 2, the beam 6 is made of a half precast concrete, and is a precast concrete beam form 8 having a substantially U-shaped cross section, a beam rebar (rebar) 9,
It is composed of concrete 12 poured and filled in the beam form 8. The beam reinforcing bar 9 surrounds the lower end bar 9a arranged in the beam form frame 8, the upper end bar 9b arranged above the upper end of the beam form frame 8, and the lower end bar 9a and the upper end bar 9b. It is composed of stirrup muscles 9c arranged in the.

As shown in FIG. 1 (b) and FIG. 2, the floor 7 is made of a half precast structure, and the precast slabs 13, 1 laid on the beams 6, 6, ...
,, and upper slab bars (not shown) arranged on the upper surface thereof, and floor concrete 14 that is cast on the upper surfaces of the beams 6 and the precast slab 13 to form the floor surface.

The joint portion A of the pile 5 and the beam 6 having the above-mentioned structure has the following structure. A pedestal 15 as shown in FIGS. 2 and 3 is arranged on the head of the pile 5. The pedestal 15 is a support member 16 placed on the pile 5.
And a receiving member (receiving member) 18 suspended from the supporting member 16 by a hanging bolt 17.

As shown in FIG. 3, the support member 16 has rods 19 and 1 each having a dimension longer than the radius of the pile 5.
9 and so on are combined in a substantially cross shape in a plan view. Each rod 19 is formed of back-to-back C-shaped channel members 19a, 19a. The channel member 19 is provided at the tip of each rod 19.
A suspension bolt 17 is passed between a and 19a, and an adjusting nut 20 for moving the suspension bolt 17 up and down is screwed to the upper end portion thereof. Further, the lower end portion of the hanging bolt 17 is fixed to the receiving fitting 18 with a nut (not shown). As a result, the receiving fitting 18 is suspended from the support member 16.

On the other hand, the receiving member 18 is ring-shaped, and is constituted by receiving member members 21 and 21 which are divided into two in a half-moon shape in plan view. Each of the receiving metal members 21 has a semicircular shape in cross section and a semicircular receiving portion located in a plane perpendicular to the axis of the tubular portion 21a and having an inner diameter approximately the same as the outer diameter of the pile 5. Portion 21b, reinforcing portion 21c, and tubular portion 21
a and a joint portion 21d formed at both ends of the receiving portion 21b. And the joint 21
d and 21d are connected to each other by fixing bolts 22, 22, and so that both receiving metal fitting members 21 and 21 are integrated.

Further, on the upper surface of the receiving portion 21b of the receiving metal member 21, claw portions 23, 23 having a substantially trapezoidal shape in a side view are formed so as to be positioned concentrically.

As shown in FIGS. 2, 4 and 5, the footing portion of the joint portion A is formed on the receiving metal fitting 18 of the pedestal 15 thus installed on the head of the pile 5. A precast concrete joint mold 25 is installed for this purpose. As shown in FIGS. 4 and 5, the connection form 25
Is a bottom mold part 25a having a substantially octagonal shape in plan view and a bottom mold part 2
Side form parts 25b, 25 which stand up from the outer peripheral edge of 5a and cover between adjacent beams 6, 6
b, ... Are integrally formed. Then, between the side mold parts 25b, 25b adjacent to each other, a notch 26 for mounting the beam mold 8 (see FIG. 5) at a position facing each beam 6 (see FIG. 5). Is formed.

As shown in FIG. 4, a circular hole 27 for inserting the pile 5 is formed in the central portion of the bottom mold part 25a. Positioning pins 28, 28, ... Are provided on the inner peripheral surface of the hole 27 so as to protrude inward for a certain length.

In the state-of-the-art mold 25 having such a structure, the claw portions 23, 23, ... Of the receiving metal fitting 18 are fitted into the holes 27 of the bottom mold portion 25a in a state of being placed on the receiving metal fitting 18. It is supposed to be crowded. Further, in this state, each claw portion 23 has
A fixing member 29 having a substantially L shape in cross section is joined by a bolt 29a. The fixing member 29 fixes the connection form 25.

As shown in FIGS. 2 and 4, reinforcing ribs (not shown) are arranged inside the joint form 25, and concrete 12 is poured and filled therein.

In this way, at the joint portion A between the pile 5 and each beam 6, the joint form 25 is installed on the upper surface of the receiving metal fitting 18 of the pedestal 15 provided on the head of the pile 5. The ends of the beams 6 are placed on the joint form 25, and the concrete 12 is placed in the joint form 25. As a result, the pile 5 and each beam 6 are integrated with each other through the connection form 25 and the concrete 12.

Next, a method of constructing the jetty 1 using the above-described joint structure will be described with reference to FIGS. 1 to 7. In advance, the pedestal 15 shown in FIG. 3 is assembled into a predetermined shape on the ground. At this time, the receiving metal fitting members 21 and 21 forming the receiving metal fitting 18 are fixed to the fixing bolt 2
2, 22, ... Are not joined and are kept in a divided state.

Further, as shown in FIGS. 6 and 7, a temporary scaffold 31 is attached to the pedestal 15. In this temporary scaffold 31, a scaffolding unit 33 is hung on a frame 32 mounted on the upper surface of the support member 16, and further a scaffolding plate 34, a curing net 35, etc. are mounted. This makes it easy to disassemble.

First, the piles 5, 5, ... Are driven into predetermined positions. Next, the pedestal 15 is suspended by a crane or the like, the pedestal 15 is lowered from above the pile 5, the head of each pile 5 is inserted into the receiving metal fitting 18, and the support member 16 is placed on the pile 5. At this time, the receiving metal fitting members 21 and 21 forming the receiving metal fitting 18 are divided without being joined by the fixing bolts 22, 22, ..., Thus, the pile 5 can be easily inserted.

In this way, when the pedestal 15 is installed on the head of the pile 5, the direction of rotation of the pedestal 15 around the vertical axis is adjusted. Further, after this, the length of the hanging bolts 17, 17, ... Is adjusted by the nut 20 to adjust the height and levelness of the receiving metal fitting 18 (the state shown in FIGS. 6 and 7).

Subsequently, the receiving metal fitting members 21, 21 forming the receiving metal fitting 18 are joined with the fixing bolts 22, 22, ..., The fixing metal fitting 18 is fixed to the pile 5. The work up to this point can be performed on the temporary scaffold 31 attached to the pedestal 15. After these operations are completed, the temporary scaffold 31 is dismantled and removed.

Then, as shown in FIG. 4, the connection form 25 is hung by a crane and installed on the metal fitting 18. At this time, the positioning pins 28, 28, ...
By being guided by 3, 23, ...
5 is accurately positioned at a predetermined position. Subsequently, the fixing members 29, 29, ... Are attached to the claw portions 23, 23, ... With bolts 29a, 29a, respectively, and thereby the connection form 25 is fixed.

Then, as shown in FIGS. 2 and 5,
After laying mortar on the lower surfaces of the cutouts 26, 26, ... (See FIG. 5) of the connection form 25, suspend the beam form 8, 8, ... It is installed on the frame 25. Then, the joint portion between each beam form 8 and the connection form 25 is caulked.

Then, as shown in FIG. 2, the lower end reinforcement 9a of the beam reinforcement 9 and the stirrup reinforcement 9c are arranged in the beam form 8. At the same time, reinforcing bars (not shown) are arranged inside the connection form 25.

After that, concrete 12 is simultaneously placed in the beam form 8 and the connection form 25. At this time, the concrete 12 is cast only up to the upper end level of the beam form 8 of the beam 6.

After the concrete 12 is hardened, the precast slab 13 is hung by a crane or the like, and the beams 6,
6, ... Build above.

Then, the upper end bars 9b, 9b, ... Of the beam reinforcing bar 9 are formed.
After arranging the slab upper bars (not shown) of the precast slabs 13, 13, ..., The floor concrete 14 is placed to form the floor 7. At this point, pile 5
Thus, the beam 6 and the floor 7 are rigidly connected.

Thereafter, the floor concrete 14 is hardened, whereby the construction of the jetty 1 shown in FIG. 1 is completed.

In the joint structure of the pile 5 and the beam 6 described above, the pedestal 15 consisting of the support member 16 and the receiving metal fitting 18 is installed on the head of the pile 5 and the precast concrete joint is mounted on the receiving metal fitting 18. A mold 25 is placed, and this mold 25
The end of the beam form 8 is placed on the
The beam form 8 has a structure in which reinforcing bars are arranged and concrete 12 is filled. This makes pile 5
The beam 6 can be joined to the beam 6 via the pedestal 15 and the concrete 12. Further, when the joint portion A is constructed, since the joint form 25 and the beam form 8 are made of precast concrete, naturally, the work of assembling and disassembling the form,
Also, it is not necessary to install a work scaffold for performing these works. Further, when the beam 6 is erected, it is sufficient to simply place the beam form 8 on the joint form 25, so that the work of constructing the beam 6 can be saved. In this way, by minimizing the work on the site, that is, on the sea surface, the labor for constructing the pier 1 can be greatly saved, the construction period can be shortened, and the construction cost can be reduced. .

In addition, since the connection form 25 is placed on the receiving metal fitting 18 of the receiving base 15 installed on the head of the pile 5, the supporting structure for supporting it is required. There is no need to install work scaffolds on the ground or in the sea. Further, since the temporary scaffold 31 is integrally attached to the pedestal 15, it is not necessary to install the scaffold in the sea when fixing the receiving metal fitting 18 or the like. As a result, the construction work can be carried out safely and smoothly without being affected by waves and tides.

Further, since the pedestal 15 is provided on the head of the pile 5, the pedestal 15 is mounted with high accuracy by absorbing the build-up error in the vertical direction of the pile 5 and the rotation direction around the axis. be able to. This makes it possible to construct the pier 1 with high accuracy and easily.

Furthermore, prior to the construction of the floor 7, concrete 12 is placed on the connection form 25 and the beam form 8. In this way, the beam 6 of the pier 1, which is a heavy object, is first constructed in advance as compared with the beam used in a general building or the like, thereby ensuring the strength and safety against the work load during the subsequent construction of the floor 7. be able to. Also, concrete 1
Since the upper surfaces of the beams 6, 6, ... And the joint portion A become substantially flat at the time of placing 2, the construction work of the floor 7 can be performed by using this as a scaffold, and the work thereafter can be extremely performed. It becomes possible to carry out safely and smoothly.

Of course, the beam formwork 8, the precast slab 13, and the connection formwork 25 are produced in the onshore production yard, so that they can be of stable and high quality, which improves the quality of the pier 1. Can be made.

In the above embodiment, the pile 5 is made of steel pipe, but of course, the support member 1 for the pedestal 15 is not required.
If 6 can be placed, a steel pipe concrete structure in which concrete is cast in the steel pipe, and further, a steel pipe reinforced concrete structure in which reinforcing bars are reinforced, a centrifugally formed steel pipe concrete structure, or a centrifugally formed concrete structure, etc. May be Further, the floor 7 is not limited to the half precast concrete structure, but may be a full precast concrete structure and the upper surface thereof may be paved, or a deck plate or the like may be adopted. In addition, if the location is such that beam type support and the like can be easily adopted, it may be formed of cast-in-place concrete. Further, although the beam 6 is made of a half precast concrete structure, it goes without saying that the same effect can be obtained even when the beam 6 is made of a full precast concrete structure.

Further, in the above embodiment, the structure to which the above configuration is applied is not limited to the pier 1, but is applied to the foundation of the building, the connection between the foundation pile of the underground structure and the underground beam, etc. Even if it does, the same effect can be produced. Furthermore,
In the above embodiment, the concrete 12 is placed on the beam form 8 and the connection form 25, the precast slab 13 is laid, and then the floor concrete 14 is placed. However, the construction order is limited. Not something to do. For example, the precast slab 13 may be laid after the beam form 8 and the connection form 25 are installed, and then the concrete 12 and the floor concrete 14 may be simultaneously placed. In addition, the upper end bar 9b of the beam rebar 9 is connected to the concrete 1
Although the reinforcements are arranged after the second driving, the lower reinforcements 9a and the stirrup reinforcements 9c may of course be arranged at the same time. In addition, the cradle 15 is assembled on land in advance,
Although it is configured to be installed on the pile 5, only the temporary scaffold 31 is attached to the support member 16 and installed on the head of the pile 5, and then the hanging bolt 17, the receiving metal fitting 18, etc. are attached to the support member 16. It may be configured to be attached to.

[0047]

As described above, according to the joint structure of the pile and the beam according to the first aspect, the pedestal including the ring-shaped receiving member and the supporting member for suspending the ring-shaped receiving member is used as the head of the pile. Installed on the receiving member, a precast concrete joint formwork was installed on the receiving member, the end of the beam was placed on this joint formwork, and concrete was filled into the joint formwork. .
As a result, the pile and the beam can be joined via the connection form and the concrete. In addition, since the joint formwork is made of precast concrete, the work such as assembling and disassembling the formwork, the supporting work and the work scaffolding for performing these works are unnecessary, and the pile and beam It is possible to facilitate the construction work of the joint portion. As a result, the on-site work can be minimized, and the labor of construction can be greatly reduced, and the construction period can be shortened and the construction cost can be reduced. At this time, since the joint formwork is configured to be placed on the receiving member suspended from the support member on the pile, the supporting work for supporting the joint formwork is not necessary, and at the time of construction, It suffices to simply place the connection form on the pedestal provided on the pile. From this point as well, the construction can be facilitated, the construction period can be shortened, and the construction cost can be reduced. Further, by joining the pile and the beam through the pedestal provided on the head of the pile, the pedestal can absorb the build-up error of the pile. This makes it possible to construct the structure with high accuracy and easily. Furthermore, especially in structures constructed on the sea such as piers,
Since the effects of tides and sea conditions are eliminated, each of the above effects becomes more prominent.

According to the method of constructing a structure according to claim 2, after the pile is erected at a predetermined position, the pedestal is attached to the head of the stake, and then the joint is provided on the receiving member of the pedestal. After the formwork was installed, the beam formwork was placed on this joint formwork, and the reinforcing bars were arranged in the joint formwork and the beam formwork and concrete was poured and filled. At this time, since the connection form and the beam form were made of precast concrete, the work such as assembling and disassembling the form, the supporting work and the work scaffolding for performing these works became unnecessary, and the pile and the beam were It can be easily integrated. As a result, the on-site work can be minimized, and the labor of constructing the structure can be greatly reduced, and the construction period can be shortened and the construction cost can be reduced. In addition, by installing the pedestal on the pile after it has been erected, the building error of the pile is absorbed,
The pedestal can be mounted with high accuracy. This allows
It becomes possible to construct a structure with high accuracy and easily. Furthermore, in particular, structures constructed on the sea such as a pier are not affected by waves, tide levels, sea conditions, etc., so that the above respective effects become more remarkable.

According to the method for constructing a structure according to the third aspect, the floor is constructed after the concrete is poured into the connection form and the beam form. Thereby, the pile and the beam can be integrated before the floor is constructed, and the strength and safety of the structure against the work load during the subsequent construction of the floor can be ensured. Also, when concrete is placed in the joint form and the beam form, the upper surfaces of the beam and the joint are almost flat, so this can be used as a scaffolding, and the work after that can be performed safely. And it becomes possible to carry out smoothly.

According to the construction method of the structure according to the fourth aspect, the temporary scaffold is integrally attached to the support member in advance. This eliminates the need to install a scaffold on the ground or in the sea, for example, when installing a cradle. From this point as well, it is possible to reduce the construction period, shorten the construction period, and reduce the construction cost.

[Brief description of drawings]

FIG. 1 is a view showing an example of a structure constructed by applying a joint structure between a pile and a beam and a construction method of a structure using the same according to the present invention, in which FIG. ) An elevational view.

FIG. 2 is a view showing a part of the structure, and is a vertical cross-sectional view showing a joint between a pile and a beam.

FIG. 3 is a perspective view showing a pedestal provided in the joint section.

FIG. 4 is a perspective view showing a joint mold provided in the joint section.

FIG. 5 is a plan view of the joint section.

FIG. 6 is a diagram showing a construction method of the structure, showing a state in which a pile is erected and a pedestal is attached to the head of the stake, in which (a) a plan view and (b) a standing view. It is a side view.

FIG. 7 is a side view of FIG. 6;

[Explanation of symbols]

 1 Pier (Structure) 5 Pile 6 Beam 7 Floor 8 Beam Form 9 Beam Reinforcement (Reinforcing Bar) 12 Concrete 16 Supporting Member 18 Receiving Metal (Receiving Member) 25 Joint Form 31 31 Temporary Scaffolding

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Bessho Tomohiro 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Daisuke Kasahara 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction (72) Inventor Yoshiyuki Ohara 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Keiichi Abe 2-8-2, Oshiage, Sumida-ku, Tokyo Okabe Stock Company ( 72) Inventor Kiichi Houshi 2-2, Oshiage, Sumida-ku, Tokyo Okabe stock company (72) Inventor Shigeo Kita 2-82, Oshiage, Sumida-ku, Tokyo Okabe stock company

Claims (4)

[Claims] 1. A structure for joining a head of a pile and a beam, wherein the head of the pile has a ring-shaped receiving member through which the pile is inserted, and the receiving member mounted on the pile. A pedestal consisting of a supporting member for suspending the member is provided, and a precast concrete molding formwork forming a joint between the pile and the beam is installed on the receiving member of the cradle, A joint structure between a pile and a beam, characterized in that an end portion of the beam is placed on the joint formwork and concrete is filled inside thereof. 2. When constructing a structure, after a pile is erected at a predetermined position, a pedestal including a ring-shaped receiving member and a supporting member for suspending the receiving member is provided on the receiving member. Of the precast concrete structure for forming a joint between the pile and the beam on the receiving member by mounting the supporting member on the pile and inserting the supporting member on the pile head. After installing a joint form, placing a precast concrete beam form on the joint form, and placing concrete by placing reinforcing bars inside the form and beam form. A method of constructing a structure, characterized by being filled. 3. The method for constructing a structure according to claim 2, wherein the floor of the structure is constructed after placing concrete in the joint form and the beam form. A method of constructing a structure characterized by. 4. The method for constructing a structure according to claim 2, wherein a temporary scaffold is integrally attached to a support member of the pedestal in advance.