JP5075398B2 - Construction method of tower-like PC structure and tension system device - Google Patents

Description

  The present invention relates to a method for constructing a tower-like PC structure such as a ventilation tower such as a road tunnel, and a tension system device for PC steel used in the tower-like PC structure.

  For example, a ventilation tunnel in a road tunnel is provided with a ventilation tower that protrudes high from the ground. This ventilation tower is constructed by stacking ring-shaped precast concrete blocks (hereinafter referred to as precast blocks) in multiple stages in the vertical direction. A PC (prestressed concrete) structure that is tightly coupled with steel is used.

  In the construction of such a ventilation tower, when the upper block is stacked on the lower block, it is performed to join the upper block and the lower block by tensioning the PC steel material. Workers moved up and down with an external scaffolding, and a tensioning device (tension jack), hydraulic device, etc. were lifted several times by a cargo handling machine (crane) and received by workers. And the worker set the supplied tension device (tense jack) one by one manually. In addition, a frame was constructed with a single tube or the like, and a curing sheet was stretched one by one.

  In addition, there exist patent document 1, 2 as a prior art document relevant to the tower-like PC structure of this invention, for example. The invention of this Patent Document 1 is applied to construction of a bridge pier, etc., and a U-shaped sheath pipe is embedded in a footing, and a precast block having a main reinforcing bar insertion hole and a PC steel wire insertion hole is footed. Stacked on top, the epoxy resin adhesive is applied to the joint surface between the blocks, the main rebar is inserted into the main rebar insertion hole from the top of the stacked block, the wire insertion hole / U-shaped sheath from PC steel After tensioning the PC steel strand inserted from above into the pipe at the top end of the uppermost block and introducing a slight longitudinal prestress, grout was injected into the wire penetration hole from the main rebar insertion hole / PC steel, and the PRC structure was To form.

  The invention of Patent Document 2 is a method for constructing a concrete pier constructed by stacking a plurality of unit precast blocks, and an upper jig of a hydraulic jack of a jackup device is attached to a groove portion of the unit precast block and jacked up. The blocks are stacked by repeating a jack-up process for forming a gap below the block and an insertion process for inserting a new block into the gap a predetermined number of times.

JP-A-8-4031 JP 2004-84322 A

  In the case of the conventional construction method as described above, (1) it takes time and labor to assemble the external scaffold, (2) it is very difficult to carry heavy tensioning devices, and (3) it is very difficult to set heavy tensioning devices. (4) There were problems such as the fact that a lot of work at high places was dangerous to install a curing sheet.

  The present invention shortens stacking of precast blocks and tensioning of many PC steels in a tower-like PC structure in which precast blocks are stacked in multiple stages and each precast block is fastened by a large number of vertical PC steels. It is an object of the present invention to provide a construction method and a tension system device for a tower-like PC structure that can be performed safely in time.

The invention of claim 1 of the present invention is a method for constructing a tower-like PC structure constructed by stacking precast blocks (precast concrete blocks) and fastening each precast block with PC steel in the vertical direction. There is an internal scaffolding inside. After the upper precast block is stacked on the lower precast block, a temporary installation with a PC steel tension device (such as a hydraulic jack) is placed on the upper precast block. Is installed, the upper precast block PC steel (PC steel bar, etc.) is tensioned by the tensioning device, the upper precast block and the lower precast block are fastened together, and the temporary work is completed when the tension work is finished. Remove the gantry from the upper precast block and stack the 1 block Under the installation of the supporting frame of the temporary tension of PC steel, a method of constructing the tower-like PC structure, characterized in that to construct a sequentially repeated Slender PC structures the removal of support cradle temporary.

The invention of claim 2 of the present invention is a construction method of a tower-like PC structure constructed by stacking precast blocks and tightly connecting each precast block with PC steel in the vertical direction. After installing a temporary support base with a tension device for PC steel on the precast block on the ground, the precast block with this support base is stacked on the lower precast block, and the support Tension the PC steel material of the upper precast block with the tension device of the gantry to fasten the upper precast block and the lower precast block, and when the tension work is finished, remove the temporary support gantry from the upper precast block, Installation of temporary support bases and stacking of precast blocks with support bases Under tension PC steel, a method of constructing the tower-like PC structure, characterized in that to construct a sequentially repeated Slender PC structures the removal of support cradle temporary.

  The present invention is applied to the construction of a tower-like PC structure such as a cylindrical ventilation tower having a horizontal cross section of hexagonal shape, circular shape, quadrangular shape or the like. The precast blocks to be stacked are ring-shaped precast concrete blocks, which are transported from a factory, for example, in half, divided into two parts, grounded at the installation location, and fastened with horizontal PC steel bars. In this grounding process, an internal scaffold is attached inside the precast block. Moreover, a partition wall is attached as needed. Such precast blocks with internal scaffolding are stacked with a large crane, vertically tensioned with PC steel for each ring, and a tower-like PC structure is constructed that is rigidly connected with a reinforcing bar and PC steel. The internal scaffold will be removed as needed.

In the first aspect of the present invention, a temporary tensioning system device is used in which a tensioning device or a hydraulic device is suspended from a support frame having the same planar shape as the planar shape of the precast block and the side surface shape of which is a gate shape. The system device is lifted with a crane and installed on the uppermost block. The vertical tension is applied, and the system is removed after the tension work is completed. In the invention of claim 3, the tension system device is previously installed on the block on the ground, and is lifted and stacked together.

  By using such a tensioning system device, (1) a heavy tensioning device or hydraulic device can be installed on the uppermost block all at once, and a heavy tensioning device can be easily set at a tension point. It is possible to carry out block stacking work and tension work for many PC steel materials in a very short time. (2) Since a heavy tensioning device is suspended from the ceiling of the support frame, work can be performed inside the block by an internal scaffolding, and work such as setting and tensioning can be performed extremely safely. (3) The support frame can be provided with a curing sheet (fall prevention sheet) that hangs down from the outer periphery of the ceiling portion, and the curing sheet can be installed simultaneously with the installation of the support frame. The conventional work of building a curing frame with a single tube, etc., eliminates the need to stretch the sheet, greatly shortening the work time, and the curing sheet covering the entire outer periphery of the work area inside the block, tensioning devices, tension parts, etc. As a result, the safety of the workers is improved and the safety and security of workers are increased despite the work at high places.

The invention of claim 3 of the present invention is a tension system device used for construction of a tower-like PC structure constructed by stacking precast blocks (precast concrete blocks) and fastening each precast block with a vertical PC steel material. Yes, a gate-shaped support frame installed on the precast block, a hanger rail provided on the ceiling of the support frame so as to be located above the tension point, and a tension that can be freely suspended on the hanger rail A tension system device comprising a device (hydraulic jack or the like).

  The gate-shaped support frame is composed of, for example, a ceiling frame corresponding to the planar outer shape of the precast block and a plurality of support legs spaced in the circumferential direction to support the ceiling frame, and the lower part of the support leg is precast It is fixed to the upper surface of the block with bolts etc. so that it can be attached and removed. A hanger rail is disposed along the ceiling frame under the ceiling frame, and a tension device is suspended from the hanger rail via a trolley / chain block or the like. A hydraulic device (hydraulic pump unit) is suspended from a ceiling beam arranged inside the ceiling frame.

  The ceiling frame / hanger rail is located above the tension point of the precast block. If the support frame is installed on the uppermost block, the suspended tension device can be set at each tension point. . By arranging multiple tensioning devices for a large number of PC steels and horizontally moving one tensioning device to perform several tensions, efficient tensioning work is possible with a small number of tensioning devices. Become.

According to a fourth aspect of the present invention, there is provided the tension system apparatus according to the third aspect , wherein a curing sheet (a fall prevention sheet such as a curing net) hanging from the ceiling portion is provided. is there.

  For example, a curing frame similar in shape to the ceiling frame is provided on the outer periphery of the ceiling frame of the support frame. For example, bars such as horizontal pipes are provided at the upper and lower ends of the curing sheet, and the upper bar is provided below the curing frame. Let it wind up. The entire outer periphery of the work location inside the block can be completely covered by simply rolling down the curing sheet. A bar material such as a pipe under the curing sheet is fixed by being brought into contact with the outer surface of the block, or placed on the upper surface of the block and fixed to prevent the tension device and the tension component from falling down.

  Since the present invention is configured as described above, the following effects can be obtained.

  (1) In the construction method of a tower-like PC structure in which precast blocks are stacked in multiple stages and fastened by PC steel in the vertical direction, an internal scaffold is provided inside the precast block, and the precast blocks with the internal scaffold are stacked. In order to construct a tower-like PC structure in which a tensioning device is set using the internal scaffolding, and is vertically tensioned with PC steel for each stage and rigidly joined with PC steel, the assembly of the conventional external scaffolding is performed. Is unnecessary, the stacking work of the blocks can be performed in a short time, and the work can be performed inside the blocks, so that the work such as setting and tension can be performed safely.

  (2) In the construction method described above, by using a temporary tensioning system device that is constructed by suspending a tensioning device or a hydraulic device on a support frame such as a gate type, It can be installed on the upper block at once, and a heavy tensioning device can be easily set at the tension point, and the stacking work of blocks and the tension work of many PC steel materials can be performed in a very short time. (B) Because the heavy tensioning device is suspended from the ceiling of the support frame, the work can be performed inside the block by the internal scaffolding, and work such as setting and tensioning can be performed extremely safely. (C) The support frame can be provided with a curing sheet that hangs down from the outer periphery of the ceiling, and the curing sheet can be installed simultaneously with the installation of the support frame. F This eliminates the need to stretch the sheet and stretch the sheet, greatly shortening the work time, and the curing sheet covering the entire outer periphery of the work area inside the block completely prevents the fall of tension devices and parts. As a result, the safety is greatly improved and the safety and security of the worker is increased despite the work at a high place.

  (3) The tension system device can be composed of a gate-shaped support frame and a hanger rail that suspends a plurality of tension devices movably above the tension point of the block. It can be performed in a short time, and an efficient tensioning operation can be performed with a small number of tensioning devices by horizontally moving one tensioning device and performing several tensions.

  (4) A curing sheet that hangs down from the ceiling can be provided on the outer periphery of the gate-type support frame of the tension system, and the entire outer periphery of the work location inside the block can be completely covered by simply lowering the curing sheet. Can do.

  Hereinafter, the present invention will be described based on the illustrated embodiments. This embodiment is an example applied to a ventilation tower of a road tunnel ventilation station. FIGS. 1-4 shows an example of the tension system apparatus used for the construction method of the tower-like PC structure of this invention. FIGS. 5-13 shows an example of the construction method of the tower-like PC structure of this invention in order of a process.

  In the embodiment of FIGS. 1 to 4, the ventilation tower is a cylindrical tower-like PC structure 1 having a hexagonal horizontal cross section, and hexagonal ring-shaped precast blocks 2 are stacked in multiple stages in plan view. The block 2 is constructed by fastening the PC steel bars 3 in the vertical direction. In the construction method of the present invention, an internal scaffold 4 is provided inside the ring block 2, and when this ring block 2 is stacked one stage, a hydraulic jack 13 of a tensioning device is installed thereon using the internal scaffold 4. Alternatively, the tension system device 10 of the present invention is installed to tension the PC steel 3. For example, a ventilation tower with a height of 45m is constructed by stacking 18 ring blocks with a height of 2.5m.

  As shown in FIGS. 1 to 3, the tension system device 10 is a chandelier type multi-jack hanger, mainly a temporary gate-type support base 11, a hanger rail 12, a tension device hydraulic jack 13, and a hydraulic pressure It comprises a pump unit 14 and a curing sheet (fall prevention sheet) such as a curing net 15.

  The support frame 11 is formed in a gate shape in a vertical cross section from the ceiling portion 11a and the outer peripheral side wall portion 11b. The ceiling portion 11a includes a ceiling frame 20 made of a hexagonal H-shaped steel or the like corresponding to the hexagonal shape of the ring block 2, and a ceiling beam 21 made of a H-shaped steel or a grooved steel that extends vertically and horizontally inside the hexagon. Consists of The outer peripheral side wall part 11b is comprised from the support leg 22 arrange | positioned at each side of a hexagon. The ceiling frame 20 is attached to the inner side of the upper part of the support leg 22, and the lower installation plate 23 is installed on the upper surface of the ring block 2 and fixed so as to be attachable / detachable with bolts or the like (see FIG. 1 (a)). Crane hook wires are connected to four places of the ceiling beam 21 so that the support frame 11 can be lifted (see FIG. 3).

  The hydraulic pump unit 14 is suspended from the ceiling beam 21 (see FIG. 1A). The hydraulic jack 13 is suspended from the ceiling frame 20 so as to be movable, as will be described later. A hexagonal curing frame 25 is provided on the outer periphery of the ceiling frame 20 via a support member 24, and a curing net 15 is attached to each side of the curing frame 25. The curing net 15 is provided with pipes 26 at the upper and lower ends, for example, and the upper pipe 26 can be mounted under the curing frame 25, rolled up and stored, and unwound to cover the entire outer periphery. The lower pipe 26 is fixed by being brought into contact with the outer surface of the ring block 2 or mounted on the upper surface of the ring block 2 to prevent the tension device or the tension component from falling down.

  As shown in FIG. 4, the hanger rail 12 is disposed below the ceiling frame 20 in parallel with the ceiling frame 20 via an attachment member 30. The hanger rail 12 is composed of a vertically arranged flat bar, and a trolley 31 having wheels that roll with the flat bar sandwiched from above and below is movably attached to the hanger rail 12. The hydraulic jack 13 is suspended from the lower portion of the trolley 31 via the chain block 32.

  Since the trolley 31, the chain block 32, and the hydraulic jack 13 can move above the outer peripheral side wall of the ring block 2, they are spaced in the circumferential direction with respect to a large number of PC steel materials spaced apart in the circumferential direction. A plurality of units are arranged, and one hydraulic jack 13 is horizontally moved so that several tensions can be applied. The hydraulic jack 13 is a center hole jack, for example, which pulls a PC steel rod to introduce a tension force and rotates a fixing nut to fix it. In addition, a wire is attached to the hydraulic jack 13, and this wire is fixed to a locking bracket provided on the support leg 22 of the support base 11 via a hook so that the hydraulic jack 13 is lifted when the support base 11 is lifted. The fall prevention and the prevention of the jump of the PC steel material by the fracture at the time of tension of the PC steel material are aimed at.

  Construction of the ventilation tower is performed in the following procedure using the tension system device configured as described above.

(1) Product loading As shown in Fig. 5, the precast block 2 transported by a low-floor trailer is lifted by a crane 40 via a balance beam 41 and installed on a ground frame installed near the ventilation tower installation location. To do. The hexagonal ring block 2 is divided into two halves for transportation, and a trapezoidal block having a planar shape is transported.

(2) Temporary product assembly As shown in FIG. 6, the block 2-1 on one side is installed on the ground frame 42. The level of the ground frame 42 is adjusted to be completely horizontal. An epoxy adhesive 43 is applied to the joining end face of the block 2-1. Install block 2-2 on the other side and pull it. Temporary fixing is performed using a horizontal PC steel bar, and curing of the adhesive is performed.

(3) Horizontal PC tension As shown in FIG. 7, the half blocks are connected by a horizontal PC steel rod 44. The block 2 has a vertical PC steel rod 3 and a reinforcing bar 5 embedded therein, and a convex portion is provided inside the block 2 to increase the joining area, and a PC steel rod 44 is buried in the joint convex portion. Deploy. The PC steel bar 44 is connected by a connecting tool 45. A hydraulic jack is set on the protruding PC steel bar 44 to be tensioned, and the fixing tool 46 is tightened and joined. After tension, fill with grout.

(4) Back surface protection mortar construction As shown in FIG. 8, bolts 48 are set on the inserts 47 of the block 2. Assemble the reinforcing bars 49 and set the formwork. A non-shrink mortar 50 is placed and cured. The horizontal PC steel bar 44 is completely buried by this back protection mortar work.

(5) Attaching the inner partition wall As shown in FIG. 9, after attaching the H-shaped steel supporting the inner partition wall to the bottom of the ring block 2, the inner partition wall 51 (four steps) is placed, Is attached to the surface of the joint projection with steel.

(6) Assembly of internal scaffold As shown in FIG. 10, temporary internal scaffolds 4 are arranged on both sides of the middle partition wall 51 and supported by a support bracket or the like at an intermediate position in the vertical direction. The internal scaffold 4 is made of, for example, a three-part expanded metal, and can be easily attached and detached. In addition, a manhole 52 with a lid through which workers can enter and exit is provided.

(7) Product Installation As shown in FIG. 11, the ring block 2 after completion of the assembly is lifted by the crane 40 and stacked on the uppermost ring block 2 that has already been joined. A rubber-made guide plate 53 is attached to the lower ring block 2 to provide an installation guide.

(8) Reinforcing bar joint injection As shown in FIG. 12, the ring block 2 is provided with a number of vertical reinforcing bars 5, and the upper and lower reinforcing bars 5 and 5 are connected by sleeve joints 60. A packing material 61 is disposed on the outer periphery between the joining end faces, and a non-shrink grout material (mortar) 62 is injected into the sleeve joint 60. The grout material 62 is injected from the lower grout injection hole 63, discharged from the upper grout discharge hole 64, and filled between the joining end surfaces of the upper and lower blocks 2, 2 and into the sleeve joint 60.

(9) Vertically connected PC tensioning work The tension system device 10 is suspended on the uppermost ring block 2 by a crane, and the lower part of the support leg 20 is fixed to the upper surface of the ring block 2 with a bolt or the like. Alternatively, the tension system device 10 is previously installed on the ring block 2 on the ground, and the tension system device 10 is set by being lifted together with the ring block 2. The curing net 15 wound up at the top is hung down to cover the entire outer periphery. As shown in FIG. 13, after the non-shrink grout material 62 between the rings generates the design strength, a predetermined tension force is introduced into the PC steel rod 3 so that the upper and lower ring blocks 2 and 2 are tightly coupled.

  A large number of vertical PC steel bars 3 are arranged between the reinforcing bars 5 and 5 on the ring block 2, and the hydraulic jack 13 is suspended from the fixing nut 70 at the top of the P steel bar 3 by the chain block 32 and set. Then, the fixing nut 70 is tightened to introduce a predetermined tension force through the fixing plate 71. For example, 12 hydraulic jacks 13 are suspended from 36 PC steel bars 3, and the hydraulic jacks 13 are horizontally moved along the hanger rails, and several units perform tension work.

  The upper and lower PC steel bars 3 and 3 are connected by a coupler 72, and a joint rubber 73 is disposed on the fixing plate 71. A PC grout material 74 is injected into the PC steel bar connecting portion from a grout injection hole 75. The PC steel rod 3 is fixed.

  By repeating the above steps a predetermined number of times, a ventilation tower is constructed in which the ring blocks 2 stacked in multiple stages are firmly connected to the PC steel bars 3 and the reinforcing bars 5. The internal scaffold 4 is removed in order from the top, and is completed by installing a small elevator.

  The construction method using the chandelier type multi-jack hanger tension system device 10 has been described above, but the hydraulic jack 13 can be directly set using the internal scaffold 4 without using this device.

  Further, the present invention can be applied not only to a ventilation tower, but also to other tower-like PC structures constructed by stacking ring blocks in a multi-stage and integrated by vertical tension.

It is an example of the construction method of the tower-like PC structure of this invention, (a) is a vertical sectional view, (b) is a partial partial side view. It is a top view which shows an example of the tension | tensile_strength system apparatus used for the construction method of this invention. FIG. 3 is a vertical sectional view of the ceiling portion of FIG. 2. FIG. 2 is a suspended portion of the ceiling portion of FIG. 2, (a) is a side view, and (b) is a vertical sectional view. It is a side view which shows an example (product carrying-in process) of the construction method of the tower-like PC structure of this invention. It is a perspective view which shows an example (product temporary assembly process) of the construction method of the tower-like PC structure of this invention. It is an example (horizontal direction PC tension | tensile_strength process) of the construction method of the tower-shaped PC structure of this invention, (a) is a perspective view, (b) is a top view. (A) which shows an example of the construction method (back surface protection mortar construction process) of the tower-like PC structure of this invention is a top view, (b) is a partial top view. It is a perspective view which shows an example (intermediate partition wall attachment process) of the construction method of the tower-like PC structure of this invention. It is an example (internal scaffold assembly process) of the construction method of the tower-like PC structure of this invention, (a) is a perspective view, (b) is a top view. It is a perspective view which shows an example (product installation construction process) of the construction method of the tower-like PC structure of this invention. It is an example (reinforcement joint part injection construction process) of the construction method of the tower-like PC structure of this invention, (a) is a top view, (b) is a vertical sectional view. It is an example (vertical connection PC tension construction process) of the construction method of the tower-like PC structure of this invention, (a) is a top view, (b) is a vertical sectional view.

Explanation of symbols

1 ... Ventilation tower (Tower PC structure)
DESCRIPTION OF SYMBOLS 2 ... Ring-shaped precast block 3 ... Vertically-oriented PC steel bar 4 ... Internal scaffolding 5 ... Reinforcement 10 ... Tension system apparatus 11 ... Portal-type support stand 11a ... Ceiling part 11b ... Outer peripheral side wall part 12 ... Hanger rail 13 ... Hydraulic pressure Jack (tension device)
14 ... Hydraulic pump unit (hydraulic device)
15 ... Curing net (curing sheet)
DESCRIPTION OF SYMBOLS 20 ... Ceiling frame 21 ... Ceiling beam 22 ... Support leg 23 ... Installation board 24 ... Supporting member 25 ... Curing frame 26 ... Pipe 30 ... Mounting member 31 ... Trolley 32 ... Chain block 40 ... Crane 41 ... Balance beam 42 ... Ground frame 43 ... Epoxy adhesive 44 ... Horizontal PC steel rod 45 ... Connector 46 ... Fixing tool 47 ... Insert 48 ... Bolt 49 ... Reinforcing bar 50 ... Non-shrink mortar 51 ... Partition wall 52 ... Manhole with lid 53 ... Guide Plate 60 ... Sleeve joint 61 ... Packing material 62 ... Non-shrink grout material (mortar)
63 ... grout injection hole 64 ... grout discharge hole 70 ... fixing nut 71 ... fixing plate 72 ... coupler 73 ... joint rubber 74 ... PC grout material 75 ... grout injection hole

Claims (4)

  It is a construction method of tower-like PC structure constructed by stacking precast blocks and connecting each precast block with vertical PC steel. Inside the precast block, an internal scaffolding is provided. After the upper precast block is stacked on top, a temporary support frame with a PC steel tension device is installed on the upper precast block, and the upper precast block PC steel is tensioned by the tension device. Then, the upper precast block and the lower precast block are tightly connected, and when the tension work is finished, the temporary support base is removed from the upper precast block, the one block is stacked, the temporary support base is installed, and the PC A tower-like PC structure that repeatedly repeats the tension of steel and the removal of the temporary support base Method of constructing the tower-like PC structure, characterized in that to build.   It is a construction method of tower-like PC structures constructed by stacking precast blocks and connecting each precast block with vertical PC steel. Precast blocks are provided on the ground with internal scaffolding inside. After installing a temporary support frame with a PC steel tensioning device, the precast block with the support frame is stacked on the lower precast block, and the upper frame of the precast block is placed by the tensioning device of the support frame. Tensioning the PC steel, the upper precast block and the lower precast block are tightly connected, and when the tension work is completed, the temporary support frame is removed from the upper precast block, and the temporary support frame is installed and supported Stacked precast blocks, tension of PC steel, temporary Method of constructing the tower-like PC structure, characterized in that to build the removal of support cradle successively repeated Slender PC structure.   It is a tension system device used for the construction of tower-like PC structures constructed by stacking precast blocks and connecting each precast block with PC steel in the vertical direction. A tension system device comprising: a hanger rail provided on a ceiling portion of the support frame so as to be positioned above the tension point; and a tension device movably suspended on the hanger rail. The tension system apparatus of Claim 3 WHEREIN: The curing sheet which hangs down from a ceiling part is provided in the outer peripheral part of the support stand, The tension system apparatus characterized by the above-mentioned.

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