JP3518666B2 - Construction method of steel pipe / concrete composite structure pier - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a steel pipe / concrete composite structure pier mainly applied to a low-middle pier having a height of about several tens of meters or less. 2. Description of the Related Art In order to construct a pier, a method of arranging vertical and horizontal bars, laying a formwork on the outer periphery thereof, and then pouring concrete inside the formwork is generally used. However, in such a method, a large number of reinforcing bars are interlaced, and it takes time to arrange the reinforcing bars, and it takes much time to assemble and disassemble the formwork.
The higher the height of the pier, the more disadvantageous it is in terms of rapid construction. [0003] In order to overcome this situation, the present applicant has installed a reaction table near the top of a steel pipe previously erected,
By constructing concrete continuously inside the sliding formwork while lifting the sliding formwork from the reaction table, rapid construction is possible even on high piers and an improvement in seismic resistance using steel pipes is provided. Developed (Patent No. 259142)
No. 2, Japanese Patent No. 2536395). [0004] Here, even when constructing a middle-low bridge pier having a height of several tens of meters, for example, about 20 to 30 m or less, the above-mentioned construction method is applied to make a normal construction. Although it is possible to improve the seismic resistance compared to a pier, the problem is that the construction time associated with the sliding formwork is relatively expensive and the time required for installation and dismantling is not always shortened. Was occurring. The present invention has been made in consideration of the above circumstances, and has as its object to provide a method of constructing a steel pipe / concrete composite structure pier capable of rapidly constructing a low-middle pier having a height of about several tens of meters. And [0006] In order to achieve the above object, a method for constructing a steel pipe / concrete composite structure pier according to the present invention is, as set forth in claim 1, a steel pipe erected in advance. A predetermined reinforcing material is placed around the surroundings, and then a formwork panel is built around the reinforcing material, and then concrete is poured inside the formwork panel. The reinforcing member is composed of a vertical streak and a PC strand wound around the vertical streak,
The PC strand drum is rotatably held about a horizontal axis on a turntable that can be turned about a vertical axis.
Installing a C strand drawing machine near the top of the steel pipe;
The PC strand is drawn from the PC strand drawer. In the method of constructing a steel pipe / concrete composite structure pier according to the present invention, first, a steel pipe is first erected on a foundation or the like, and then a vertical streak or the like is provided around the steel pipe. Place reinforcements. Next, a form panel is erected around the reinforcement, and then concrete is poured into the form panel. [0010] In this way, since the reaction force can be taken from the steel pipe that has been erected before mounting the reinforcing material and installing the formwork panel, these operations are facilitated, and the slip-form method is indispensable. By eliminating the need for installation and dismantling of lifting equipment that can not be done, and by making the formwork required for concrete casting into a panel shape,
The work of assembling and dismantling the formwork is reduced. Therefore, for a pier having a height of about several tens of meters, the cost and the construction period required for the construction can be significantly reduced as compared with the case where a slip pier construction method which is optimal for a high pier is adopted. The bridge pier formed by the construction method according to the present invention has a composite structure of steel pipe and concrete, and allows the steel pipe to bear large bending strength and shear strength.
Great improvement in seismic resistance can be expected compared to the C pier. As for the steel pipe, a large diameter pipe may be erected alone, or a plurality of small diameter pipes may be erected. Here, in the case of a large diameter, it is conceivable to join segments in the vertical direction and the circumferential direction and finally form a single large-diameter steel pipe, and in the case of a small diameter, It is conceivable that they are joined only to Further, when the height of the pier is low, it is conceivable to carry the integrally manufactured steel pipe to the site and stand it. The steel pipe mainly has a circular hollow cross section, but it goes without saying that a square steel pipe or the like may be used. Further, the cross-sectional shape of the pier is arbitrary. In particular, when a plurality of steel pipes are erected, the pier cross-section can be set to a desired shape. As the reinforcing member, a normal reinforcing bar may be used in the longitudinal direction and the circumferential direction as in the past, but the reinforcing member may be wound around the longitudinal bar and the PC around which the reinforcing bar is wound.
If it is composed of strands, the bending work required when using spiral streaks and the joining work of the spiral streaks is not required, and the PC strands are lightweight and have high tensile strength, so that they can be used during installation. The workability and the required pitch can be improved, and further rapid construction is possible. Here, when the PC strand is wound around a vertical streak, a work scaffold is constructed around the steel pipe, an endless track is laid on the scaffold, and the PC strand is wound around the PC steel wire reel stand along the track. May be spirally wound, but a PC strand unwinding machine in which a PC strand drum is rotatably held about a horizontal axis on a turntable that can be turned about a vertical axis is used as the top of the steel pipe. Installed in the vicinity, and the PC strand drawer
If the C strand is pulled out, the labor and installation space for constructing a work scaffold for laying the endless track is not required, and no equipment is needed to lift the endless track together with the PC steel reel stand. It becomes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for constructing a steel pipe / concrete composite structure pier according to the present invention will be described.
This will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to components and the like that are substantially the same as those in the related art, and description thereof is omitted. (First Embodiment) FIG. 1 is a flowchart showing a procedure of a method of constructing a steel pipe / concrete composite structure pier according to the present embodiment. In this embodiment, first, as shown in FIG. 2 (a), a rising portion of a steel pipe 2 is erected on a foundation 1, and concrete 3 is poured into a lower portion of the steel pipe to be integrated with the foundation 1. At the same time, concrete 4 is cast around the steel pipe 2 using a normal formwork or the like to construct the lower skeleton 5a (FIG. 1, step 101). Next, as shown in FIG. 2B, a tower crane 6 is set on the concrete 3 in the steel pipe 2, and then,
Using the tower crane, the panel-shaped segment 2a, which is a component of the steel pipe 2, is erected at a predetermined position, and sequentially joined in the height direction and the circumferential direction by welding, high-strength bolts, and the like (FIG. 1, step 102). . In joining the segments 2a, a work scaffold 7 attached to a post of a tower crane 6 so as to be able to move up and down can be used. In addition, the tower crane 6 is appropriately climbed along with the erection of the segment 2a of the steel pipe 2, and the work platform 7 is also moved upward. Next, as shown in FIG. 3, after assembling the steel pipe 2 to a predetermined height, a reinforcing bar holder 11 is attached to the steel pipe by welding or the like, and then a vertical bar 12 as a reinforcing material is used using a tower crane 6. And hang it around the steel pipe 2
Reinforcing bar holder 11 while being sequentially connected upward by pressure welding or the like
(Step 103 in FIG. 1). Such a reinforcing bar holder 11 may be fixed to the segment 2a of the steel pipe 2 on the ground in advance, or may be installed at a predetermined position and then attached using the work scaffold 7. The vertical streaks 12 are arranged around the steel pipe 2 at a pitch of, for example, several ゜, but for convenience, only the vertical streaks visible at both ends are shown in FIG. Next, a steel wire reel stand 14 is installed on the work scaffold 13 constructed around the steel pipe 2, and a PC strand 15 as a reinforcing material is fed out from the steel wire reel stand and spirally wound around the vertical streak 12. (Step 104 in FIG. 1). The steel wire reel stand 14 runs on a rail, which is an endless track laid on the bracket of the work platform 13, while extending the PC strand 15, and can go around the steel pipe 2. The PC strand 15 having a diameter of, for example, about 10 mm is preferably wound around the vertical streak 12 at a pitch of several hundred mm. By winding the PC strand 15, the side of the concrete is constrained to improve the compressive strength of the concrete, prevent cracking, skin falling or peeling of the concrete, and increase the toughness up to the destruction, thereby improving the seismic resistance. Performance can be improved. Next, the form panel 16 is erected at the place where the winding of the PC strand 15 is completed (FIG. 1, step 105). The formwork panel 16 is laid on the ground, suspended by a tower crane 6, and then firmly fixed at a predetermined position by taking a reaction force from the steel pipe 2 via a separator or the like. The formwork panel 16 can be constituted by, for example, a half of a cylindrical one if the pier frame is small in diameter, and if the pier frame is large in diameter, it can be formed by For example, it can be configured by dividing into several tens of squares in the circumferential direction. Here, a webbing 17 made of H-shaped steel, steel pipe, or the like is provided on the back surface of the form panel 16 so as to support the pressure of concrete. Next, concrete is cast between the form panel 16 and the steel pipe 2 (step 106 in FIG. 1). After the strength is developed, the concrete is dismantled and prepared for diversion. As described above, a series of steps such as the installation of the steel pipe 2, the installation of the vertical bar 12, the winding of the PC strand 15, the installation of the form panel 16, and the concrete placement are appropriately repeated upward, as shown in FIG. The intermediate skeleton 5b of the pier as shown in FIG. Finally, as shown in the figure, the upper skeleton 5c adjacent to the bridge girder 21 is constructed, and the construction of the pier skeleton 5 is completed. In constructing the upper skeleton 5c, a lid or the like (not shown) is provided in advance on the inside of the upper part of the steel pipe 2 in order to enhance the integration between the steel pipe 2 and the bridge girder 21, and concrete is filled above the lid. Is good. FIG. 5 is a cross-sectional view of the skeleton 5 constructed in the above-described procedure. Concrete 31 is wound around a circular steel pipe 2 and a vertical streak 12 is formed near the surface of the concrete. It can be seen that the PC strands 15 are arranged. As described above, according to the method for constructing a steel pipe / concrete composite structure pier according to the present embodiment, the installation of the reinforcing members such as the vertical bars 12 and the PC strands 15 and the installation of the form panel 16 are performed in advance. Since the reaction force can be taken from the erected steel pipe 2, these operations can be performed easily, and the installation and dismantling of the lifting equipment, which is indispensable in the slip-form method, is eliminated. By making the formwork necessary for the panel into a panel shape, labor for assembling and dismantling the formwork is reduced. Therefore, with regard to a pier having a height of about several tens of meters, the cost and construction period required for the construction can be significantly reduced as compared with the case where a slip pier method which is optimal for a high pier is adopted. The bridge pier 5 formed by the construction method according to the present embodiment has a composite structure of the steel pipe 2 and the concrete 31 and also allows the steel pipe to bear a large bending strength and a shear strength. It is expected that the seismic resistance will be greatly improved compared to the RC piers. In addition, according to the method of constructing a steel pipe / concrete composite structure pier according to the present embodiment, the reinforcing material is
And the PC strands 15 wound around the vertical streaks, there is no need for bending work or joint work between the reinforcing bars as compared with a case where a reinforcing bar such as a spiral streak is arranged around the vertical streaks 12. Further, since the PC strand 15 is lightweight and has high tensile strength, the workability at the time of mounting and the handling at the time of transportation are facilitated, and the required pitch can be increased. Thus, further rapid construction can be realized. Although not specifically mentioned in the present embodiment, the steel pipe 2 is installed, the vertical bar 12 is attached, and the PC strand 1 is mounted.
The winding of No. 5 may be performed to the design height at a time, and then the form panel 16 may be repeatedly laid and concrete poured one lift at a time.
And the work related to concrete placing may be performed in parallel. In this embodiment, the segment 2
a was sequentially joined in the height direction and the circumferential direction to form the steel pipe 2, but may be a ring-shaped shape depending on the diameter and thickness, or may be an integrally manufactured one depending on the height of the pier. You may carry in to a site and erect this. Although not particularly mentioned in the present embodiment, it is needless to say that the construction efficiency of the form panel 16 should be increased as much as possible. (Second Embodiment) Next, a second embodiment will be described. It is to be noted that the same reference numerals are given to components and the like that are substantially the same as those in the above-described embodiment, and description thereof will be omitted. The method for constructing a steel pipe / concrete composite structure pier according to the present embodiment differs from the first embodiment in which the steel pipe has a single large diameter, and a plurality of small diameter pipes are erected and the PC strand 15 is pulled out. There is another configuration for the mechanism. That is, in the method for constructing a steel pipe / concrete composite structure pier according to the present embodiment, first, FIG.
As shown in (1), rising portions of four steel pipes 42 are erected on the foundation 41. When the steel pipe 42 is erected, for example, a steel pipe receiving stand (not shown) is previously installed on the root bottom,
It may be set up on this. Next, the reinforcing bar holder 11 is attached around the steel pipe 42 by welding or the like, and the vertical bar 12 is built around the steel pipe 42 as shown in FIG. . Next, a PC strand drawer 43 is installed on the top of the steel pipe 42, and the PC strand drawer 43
The C strand 15 is drawn out and wound around the longitudinal streak 12, and then deep concrete is cast and the steel pipe 42 is fixedly fixed. FIG. 7 is an overall perspective view showing the PC strand drawer 43, and FIG. 8 is a side view and a front view thereof.
As can be seen from these figures, the PC strand drawer 4
Reference numeral 3 denotes a PC strand on which a rotary table 45 is mounted on a gantry 44 so as to be pivotable about a vertical axis, and four under rollers 47 are mounted on the rotary table 45, and the PC strand 15 is wound by the under rollers. The flange of the drum 46 is configured to receive the flange. With this configuration, the PC strand drum 46 can be held so as to be rotatable about both horizontal and vertical axes. Here, as shown in FIG. 8A, a rotating operation arm 49 for manually rotating the rotating table is attached to the rotating table 45, and the gantry 44 and the rotating table 4 are rotated.
A disc brake 48 is provided between the rotary table 5 and the drive lever 5, and the rotation speed of the turntable 45 can be adjusted by operating the brake with an operation lever 56 (FIG. 7). As shown in FIG. 8B, the turntable 45 is provided with a rotation speed adjustment brake 50 for adjusting the rotation speed of the under roller 47 and an operation lever 51 for operating the brake. As shown in FIG. 7, the four under rollers 47 are connected two by two via a rotating shaft 57 and are arranged in front and rear.
Are installed on one side of them as shown in FIG. 8 (b). Also, one edge of the turntable 45 has a PC
A steel wire drawing frame 52 is erected and a pair of vertical rollers 53a, 53a and a pair of horizontal rollers 53 are provided above the frame.
b and 53b are arranged in a grid pattern, and the PC strand 15 drawn from the PC strand drum 46 is passed through an outlet port 54 which is an opening surrounded by the vertical roller 53a and the horizontal roller 53b. , PC
The strand 15 can be pulled out smoothly. Further, the cage-shaped protective cover 55 is detachably mounted on the turntable 45, and the PC strand drum 46 jumps out (drops off from the under roller 47) during the work of pulling out the PC strand 15. And when the PC strand 15 runs out, it can be replaced with a new PC strand drum 46. In order to wind the PC strand 15 around the longitudinal streak 12 using the PC strand drawer 43, the PC strand drawn from the PC strand drawer 43 is used.
The ends of the strands 15 are fixed on, for example, a foundation 41 (FIG. 6), and then the PC strands 15 are pulled out from the PC strand drawer 43 and wrapped around the vertical streaks 12 spirally from below to above. Good. At this time, the PC strand drum 46 pivots around the horizontal axis by the action of the under roller 47 and pivots around the vertical axis by the action of the turntable 45. Can be wound spirally. Further, the PC strand 15 is moved by the PC strand drum 4 by the friction reducing action of the vertical roller 53a and the horizontal roller 53b.
6 can be pulled out smoothly. In addition, the operating lever 51 is operated in accordance with the pull-out speed of the PC strand 15 to appropriately adjust the rotation speed of the under roller 47, and the operating lever 56 is operated in accordance with the winding speed of the PC strand 15 to rotate the turntable 45. Adjust the speed appropriately. PC using PC strand drawer 43
When the winding of the strand 15 and the fixing of the steel pipe 42 are completed, the PC strand drawer 43 is once removed, and then the steel pipe 42 is vertically extended as shown in FIG. P on top of 42
The C strand drawer 43 is replaced. Next, the vertical bar 12 is erected around the steel pipe 42 and fixed to the reinforcing bar holder 11 while being connected to the vertical bar 12 extending from below by a pressure welding joint, a mechanical joint or the like. In the same manner as described above, the PC strand 15 drawn from the PC strand drawer 43 is wound. Next, the form panel 16 is erected at the place where the winding of the PC strand 15 is completed. Formwork panel 16
In the same manner as in the first embodiment, after grounding on the ground and suspending it with a tower crane, it can be firmly fixed at a predetermined position by taking a reaction force from the steel pipe 42 via, for example, a separator. it can. Other descriptions of the formwork panel 16 are the same as those of the first embodiment,
Here, the description is omitted. Next, concrete is poured between the form panel 16 and the steel pipe 42, and after the strength is developed, the concrete is dismantled and prepared for diversion. FIG. 9 (b) is a view showing a state where concrete has been poured to the vicinity of the top of the steel pipe 42 that has been added and the first-stage construction of the pier body has been completed. The second stage may be constructed according to the same procedure as the first stage. FIG. 10 shows a state in which the above-described procedure has been repeated to temporarily remove the PC strand drawer 43, add the steel pipe 42, rearrange the PC strand drawer 43, attach the vertical bar 12, and wind the PC strand 15. FIG. 11 is a view showing a state in which concrete is poured between the formwork panel 16 and the steel pipe 42 to complete the second-stage construction of the pier frame. As described above, according to the method for constructing a steel pipe / concrete composite structure pier according to the present embodiment, as in the first embodiment, the mounting of the reinforcing material such as the vertical bars 12 and the PC strands 15 and the forming panel. At the time of the construction of No. 16, since the reaction force can be taken from the steel pipe 42 erected in advance, these operations can be easily performed, and the installation and dismantling of the lifting equipment and dismantling which are indispensable in the slip form method are required. In addition, since the formwork required for concrete casting is formed in a panel shape, labor for assembling and dismantling the formwork is reduced. Therefore, with respect to a pier having a height of about several tens of meters, the cost and construction period required for the construction can be significantly reduced as compared with the case where a slip form method which is optimal for a high pier is adopted. The bridge pier formed by the construction method according to the present embodiment has a composite structure of the steel pipe 42 and the concrete, and also allows the steel pipe to bear a large bending strength and a shear strength. Great improvement in seismic resistance can be expected compared to piers. Further, according to the method for constructing a steel pipe / concrete composite structure pier according to the present embodiment, the reinforcing material is
And the PC strands 15 wound around the vertical streaks, there is no need for bending work or joint work between the reinforcing bars as compared with a case where a reinforcing bar such as a spiral streak is arranged around the vertical streaks 12. Further, since the PC strand 15 is lightweight and has high tensile strength, the workability at the time of mounting and the handling at the time of transportation are facilitated, and the required pitch can be increased. Thus, further rapid construction can be realized. Further, according to the method for constructing a steel pipe / concrete composite structure pier according to the present embodiment, the PC strand drum 46 is placed on the turntable 45 which can turn around the vertical axis.
Is installed near the top of the steel pipe 42 so as to be rotatable about a horizontal axis.
Since the PC strand 15 is pulled out from the C strand drawer, the labor and installation space for constructing a work scaffold for laying the endless track is not required, and
Equipment for lifting the endless track together with the PC steel wire reel stand is not required. Although not particularly mentioned in the present embodiment, the installation of the steel pipe 42, the installation of the vertical bar 12, and the winding of the PC strand 15 are performed at one time to the design height, and thereafter the installation of the form panel 16 is performed. Alternatively, the concrete placement may be repeatedly performed one lift at a time. As described above, the steel pipe according to the present invention
According to the method of constructing a concrete composite structure pier, a reaction force can be taken from a steel pipe that has been erected in advance in attaching a reinforcing material and building a formwork panel, so that these operations can be performed easily. In addition, there is no need to install and disassemble lifting equipment, which is indispensable in the slip form method. Further, since the formwork required for concrete casting is formed into a panel, the time required for assembling and dismantling the formwork is reduced. Therefore, with respect to a pier having a height of about several tens of meters, the cost and construction period required for the construction can be significantly reduced as compared with the case where a slip pier method which is most suitable for a high pier is adopted. The bridge pier formed by the construction method according to the present invention has a composite structure of steel pipe and concrete, and allows the steel pipe to bear large bending strength and shear strength.
Great improvement in seismic resistance can be expected compared to the C pier. Further, according to the method for constructing a steel pipe / concrete composite structure pier according to the present invention, the bending work and the joint work between the reinforcing bars are not required as compared with a case where a reinforcing bar such as a spiral bar is arranged around the vertical bar. It becomes. In addition, since the PC strand is lightweight and has high tensile strength, the workability at the time of installation and the handling at the time of transportation are easy, and the required pitch can be widened, and thus, further rapid construction can be achieved. Also play. Further, according to the method for constructing a steel pipe / concrete composite structure pier according to the present invention, the labor and installation space for constructing a work scaffold for laying an endless track are not required, and the endless track is connected to a PC steel wire. This also has the effect of eliminating the need for equipment for lifting with the reel stand. [0061]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a procedure of a method for constructing a steel pipe / concrete composite structure pier according to a first embodiment. FIG. 2 is a view showing a state in which a pier is being constructed in accordance with a method of constructing a steel pipe / concrete composite structure pier according to the first embodiment, and FIG. 2 (a) is a cross-section showing a state in which a lower skeleton is being constructed; FIG. 2 (b) is a side view showing a state where a steel pipe is erected thereon. FIG. 3 is a view showing a state in which a pier is continuously constructed, and (a) shows suspension of a vertical streak around a standing steel pipe;
FIG. 3B is a cross-sectional view showing a state where the PC strand is wound around the vertical streaks and the form panel is being arranged, and FIG. FIGS. 4A and 4B are diagrams showing a completed pier, wherein FIG. 4A is a cross-sectional view and FIG. FIG. 5 is a horizontal sectional view taken along line AA of FIG. 4; FIG. 6 is a view showing a state in which a pier is being constructed in accordance with a method of constructing a steel pipe / concrete composite structure pier according to the second embodiment, and FIG. 6 (a) is a side view showing a state in which a lower skeleton is being constructed. FIG. 3B is a horizontal sectional view along the line BB. FIG. 7 is an overall perspective view of a PC strand drawer 43 used in the construction method of the second embodiment. FIG. 8 is a side view and a front view of the PC strand drawer 43; FIG. 9 is a view showing a state in which a pier is continuously constructed, and (a) is a diagram in which a vertical streak is suspended around a standing steel pipe;
A side view showing a state in which the PC strand is wound around the vertical streaks and a form panel is being arranged, and (b) is a side view showing a state in which the first-stage construction has been completed by performing concrete casting. . FIG. 10 is a side view showing a state where the second stage of the pier is continuously constructed. FIG. 11 is a side view showing a state where the second-stage construction has been completed. [Description of Signs] 2, 42 Steel Pipe 5 Bridge Pier 12 Vertical Bar (Reinforcing Material) 14 PC Steel Wire Reel Stand 15 PC Strand 16 Formwork Panel 43 PC Strand Extractor 44 Mount 45 Turntable 46 Drum for PC Strand

Claims (1)

(57) [Claims] [Claim 1] A predetermined reinforcing material is arranged around a steel pipe erected in advance, and then a form panel is built around the reinforcing material. A method of constructing a steel pipe / concrete composite structure pier for casting concrete inside the formwork panel, wherein the reinforcing material is composed of a vertical streak and a PC strand wound around the vertical streak, and around a vertical axis. A PC strand drawer in which a PC strand drum is rotatably held about a horizontal axis on a turntable that can be turned around is installed near the top of the steel pipe, and the PC strand is pulled out from the PC strand drawer. Construction method of steel pipe / concrete composite structure pier characterized by drawing.