JP3395944B2 - Underwater formwork method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater formwork method for placing underwater concrete in revetment work.

[0002]

2. Description of the Related Art Conventional underwater formwork used for revetment construction is a combination of metal foam into a panel, or a large format formwork with a steel plate and a bone member attached to form a panel. The mold is fixed with a large number of separators. Moreover, the concrete structure to be constructed is reinforced concrete, and the reinforcing bars are arranged inside the formwork to pour the concrete.

[0003]

The conventional construction method using an underwater form has the following problems even though it has certainty and performance. (1) Underwater rebar is required as a structure. (2) Since the cross-section performance of the form material is low, the bone member (vertical flap,
The installation interval of the horizontal flap becomes narrow, and a large number of separators are required to fix the formwork to resist the lateral pressure of concrete. (3) Due to the reasons (1) and (2) above, it is difficult to construct a narrow cross section. (4) Due to the reason (2) above, when the separator is taken from the concrete surface of the existing revetment, the strength and thickness of the existing concrete become a problem. (5) Since the form material is used as a temporary material, the work of demolding the form is required, which requires extra days. (6) Since the formwork is made of steel, the rusting due to seawater progresses remarkably, which causes a problem that the number of diversions decreases due to the rusting of the formwork material (dirt on the concrete surface due to rust, etc.). (7) Due to the reasons (1) to (6) above, the work yard area is large (underwater rebar framing, formwork processing and storage), more work is required by the diver, and the number of man-made inputs is also increased. It is not suitable for rapid construction such as restoration work after the earthquake, because there is always the problem of cost increase due to the large amount of work and the possibility of process delay. Recently, in order to solve the above-mentioned problems, an example of using FRP (tempered glass) as a form material is increasing, but a form that has a function as a structure by using both temporary construction and permanent construction. There are almost no examples of materials or construction methods.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional example, to reduce the amount of underwater concrete and the amount of rebar as a structure, and to eliminate the need for a large number of separators, thus reducing the work of a diver in the sea. It is therefore an object of the present invention to provide an underwater mold construction method capable of reducing the cost and also capable of remarkably shortening the steps because it is not necessary to remove the mold.

Further, according to the present invention, it is possible to deal with the gable form as well, by simply changing the mounting interval of the frame support material without the need for machining each according to the change of the cross section to be installed and the gable form. It is to provide an underwater formwork method most suitable for rapid construction in which the separator can be used as a submersible rebar.

[0006]

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention firstly places a chemical anchor in advance on the concrete surface of an existing caisson as an existing revetment, and then forms a PC board on the seabed. A PC used as part of the underwater formwork / mainly constructed structure by installing a lower fixing device consisting of a lower pedestal and each member of a normal fixing jig and introducing prestress as a front formwork. The plate is placed on the lower fixing device and installed in the sea, and the conducting material of the upper fixing device is installed on the upper part of the PC plate , which is supported from the land side by earth retaining support work, continuous with the chemical anchor, and tumbled. Alternatively, the length can be adjusted with a long nut so that it can follow the changes in each installed length and that the number of members is reduced so that durability does not occur even if bending stress is applied. The upper and lower sides of the PC board and the chemical anchors placed on the concrete surface of the existing caisson as the existing revetment are tightly connected with each other with a tar, the gable formwork is assembled, and then the underwater concrete is placed and the gable formwork is demolded. The main point is to do.

Secondly, the gable form is made up of a frame receiving material which is a frame material, a horizontal joint material for fixing the frame receiving material, and a metal foam inserted into the frame receiving material.

More specifically, the present invention is manufactured by introducing prestress at the factory instead of the steel formwork (large formwork form made of metal foam or iron plate) used in the underwater formwork for civil engineering work. A concrete board (PC board) is used, which has high strength as a structure having excellent cross-sectional properties. For installation of the PC board, an underwater anchor (chemical resin anchor) is placed in advance on the concrete surface of the existing revetment, then the PC board is installed in the sea and tightly connected with a separator.

As described above, instead of using the form material as a temporary material as in the prior art, stress calculation as a structure is performed, and a structure having both the required amount of reinforcing bars and the permanent structure is provided. For that purpose, the temporary construction (at the time of construction) has the ability to withstand the stress when suspending the PC board, the wave pressure that repeatedly acts after the PC board is installed, and the lateral pressure of the concrete when pouring underwater concrete,
Moreover, it is necessary for the main installation (after completion) to resist design stress (tensile force, bending stress) and ensure the durability of the structure.

In order to economically carry out rapid construction,
A PC board, which is a thin member made of reinforced concrete using pre-stress, which can be integrated with underwater concrete as a part of the structure of the permanent construction and uses the prestress to maximize the pitch of the separator due to its sectional performance. adopt.

In this way, according to the present invention as set forth in claim 1, since the PC plate has the amount of reinforcing bars required for the design cross section, the underwater reinforcing bars are not required as the structure, and the PC
Due to the cross-sectional performance of the plate, the bone members (longitudinal flap, lateral flap) used in the conventional construction are unnecessary, and the number of separators can be reduced. Also, because prestress is used, P
The thickness of the C plate can be reduced, and workability in a narrow cross section is also good.

Since the number of separators used is small, the reliability of the separator is increased without impairing the range of influence (wedge effect) of the chemical anchor driven into the existing revetment.
Further, since the PC board is used both as a temporary material and a permanent material, there is no need to remove the mold, and since it is a factory product, there is no variation in quality and the concrete surface is beautiful and firm.

In addition to the above-mentioned action, a conductive material (an earth retaining support is fixed by a chemical anchor) is installed from the land side,
By fixing it to the PC board, it is possible to resist wave pressure (push wave).

According to the second aspect of the present invention, even when the gable formwork is constructed by using the H-section steel, the metal foam, and the iron plate together, the gable formwork is changed one by one according to the change of the cross section where the formwork is installed. It is most suitable for rapid construction because it does not need to be processed, it can be dealt with only by changing the mounting interval of the frame receiving material, and the separator of the gable form can be used as a submersible rebar.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a vertical sectional side view of an essential part showing one embodiment of the underwater formwork method of the present invention, FIG. 2 is a side view of the same gable form part, and FIG. 3 is a plan view of the same as above. A front formwork using the PC board 1 is installed in the direction, and a gable formwork using a combination of H-section steel, metal foam, and an iron plate is installed in the cross-sectional direction. 3 in the figure is an existing caisson as an existing revetment.

First, the front formwork using the PC board 1 will be described. As the constituent members, the PC board 1 and the existing caisson 3 and the PC board 1 used as a part of the underwater formwork / main structure. Is fixed and resists wave pressure (pulling wave) and lateral pressure of underwater concrete during construction, and after completion is responsible for design stress (tensile force, bending stress, etc.) separator 4 for upper and lower parts (underwater anchor type) As shown in FIGS. 6 and 7, the upper fixing device 6 that resists wave pressure (pushing wave) only during construction and fixes the upper portion of the PC board 1 at the normal position, and the foot of the sea floor of the PC board 1 It consists of a lower fixing device 5 for fixing and securing the normal line of the quay.

Each of the constituent members will be described below. As shown in FIG. 4, the PC board 1 has a rectangular cross section with a constant thickness (a polygonal cross section where the seabed ground height changes).
As shown in FIG. 5, it is a thin member reinforcing bar structure using prestress which is connected by engaging the protrusions of the concave portion 1a and the convex portion 1b at both ends. The amount of rebar and the amount of PC steel of the PC plate are determined by design stress, and the shape (width, length, thickness) is determined by workability, durability, and economy. Due to workability and productivity, the thickness of the PC board 1 is constant, and the width and length (height in the vertical direction) per PC board 1 is the extension distance (installation caisson 3 Length) and the seabed height. At this time, the length of the PC board 1 is set to a length (height) that does not hinder the work of the superstructure in the subsequent process as much as possible and that can reduce the work between tides.

The width of the PC board 1 is a standard type (having a constant width) and an irregular type (each having a different width) in order to match the length of the existing caisson 3 with the installation extension of the PC board 1.
[Standard type from left to right in Fig. 4, variant type at right end]
There are two types.

Although not shown in the figure, a notch or the like is provided in the PC board 1 for attaching an accessory structure installed on the front surface of the PC board 1. An insert metal piece (female screw) is embedded at the time of manufacturing the PC board 1 for unloading the PC board 1, installation, installation of the upper fixing device 6, mounting of the bracket, and mounting of the formwork material of the superstructure in the next step.

The design stress used for manufacturing the PC board is
The cross section with the maximum planned water depth will be adopted, and the structure will satisfy the stress during construction and after completion.

Since the existing caisson 3 which is less damaged by the earthquake during the earthquake recovery work is designed to be wound up and reused as it is in concrete, the concrete thickness from the front surface of the PC board 1 to the existing caisson 3 varies. Therefore, as shown in Fig. 10, the length of the separator (underwater anchor type) 4 can be adjusted with a tan buckle or long nut (left, right screw type), and it can be adjusted according to the length of each installed. The number of members constituting the separator is reduced so that it is possible to follow and there is no problem in durability even if bending stress is applied.

Since the separator 4 for the lower part is functionally designed so as to function as a separator and a tensile reinforcing bar, it is economically designed. Therefore, one of the lateral pressure of the concrete and the designed tensile stress, whichever is larger, is used in advance to separate the anchor part and the separator. Conduct a tensile test on the constituent members of, and manufacture with a material that can withstand the stress.

The anchor portion 4a of the separator 4 has a ring-shaped head portion from the viewpoint of load bearing characteristics.
When the anchor 7 is driven into the tip of the ring, a rectangular parallelepiped projection is provided to serve as a margin for gripping the impact wrench.

The anchor 7 to be driven into the existing caisson 3 side of the separator 4 has a slightly different diameter in the upper and lower stages, so that one of them is divided by plating so as not to make a mistake in its use.

As shown in FIGS. 6 and 7, the upper fixing device 6
Is a guide member 8, a guide member support 9 and a guide member support upset 10
It consists of each member. The conductive material 8 is used as a guide when positioning the PC board 1 and installing the PC board 1, and is integrated with the PC board until the underwater concrete is placed so that the wave pressure (pressing force) is uniformly received. It is installed, H
A shaped steel or a mountain retaining bracket 8a is used. The bracket 8a is fixed to the PC board 1 by inserting a bolt into the insert embedded at the time of manufacturing the PC board 1.

The conductive material support 9 supports the conductive material 8 and transmits the wave pressure (pushing wave) to the conductive material support work, which is raised to the abutment 10.
It consists of a giraffe jack and a clasp. The guide material support support upset 10 supports the support material support 9 and transmits wave pressure (pushing wave) to the concrete surface of the existing caisson 3 and fixes the support support upholstery 10. Chemical anchor 11
Resists wave pressure (pulling wave). The guide material support structure 9 has a structure in which the giraffe jack installed on the top end of the hitting concrete of the existing caisson 3 is received by the piece material of the mountain retaining material.

The conductor supporting members 9 are installed at a pitch of about several meters, and the upper portions of the conductor supporting members 9 are horizontally spliced in order to resist oblique waves and prevent the displacement of each conductor supporting member 9. Secure with wood (angle steel). Further, a safety passage is provided by a single pipe and a scaffold plate on the guide material support 9, and it is used as a concrete placing scaffold when pouring underwater concrete.

As shown in FIGS. 8 and 9, the lower fixing device 5 is composed of a PC plate lower pedestal 13 and a normal fixing jig 14. Among them, the PC board lower pedestal 13 is one in which H-shaped steel is installed on the rubble of the seabed, the height of the PC board 1 is made uniform, and the weight of the PC board 1 is smoothly transmitted to the rubble mound. At the same time, it has a role of transmitting the wave pressure (pushing wave) received by the PC board 1 to the normal fixing jig 14 to be described later.

For the person contacting the rubble mound of H-section steel, concrete 15 is placed on land in advance in order to increase the ground contact area. At this time, reinforcing bars are welded to the ribs of H-shaped steel so that the concrete 15 does not peel off, and the reinforcing bars are arranged on the reinforcing bars to form a reinforced concrete structure. The length of production will be shorter than the design extension in consideration of the interaction with the adjacent caisson because the normal of the quay is broken and the height of the rubble mound on the seabed is like a platform.

Although not shown, a steel camber is driven between the PC plate 1 and the H-shaped steel to prevent the PC plate 1 from shaking due to waves. In addition, since the PC board lower pedestal 13 is integrated with the normal fixing jig 14 and resists wave pressure (pushing wave), it is buried in concrete when pouring underwater concrete. For this reason, the PC board lower pedestal 13 is preferably made of scrap H-shaped steel.

The normal fixing jig 14 is the above-mentioned PC board lower support 13
It will be installed in order to resist wave pressure (push wave and pull wave) and to secure the normal of the quay by being integrated with. The normal fixing jig 14 is made by welding an iron plate to both ends of a H-shaped steel of a certain length, welded to the above-mentioned PC plate lower pedestal, and installed on the seabed by a diver, and then the length of the remaining part. Measured by a diver. Based on the measured value, H of a predetermined length on land
Shaped steel is manufactured, the above iron plates are welded to both ends, submerged in the sea, and fixed to the lower support of the PC plate with bolts.

At the tip of the normal fixing jig 14, in order to resist wave pressure (pulling wave), a chemical anchor 11 is placed on the concrete surface of the existing caisson 3 and fixed with the normal fixing jig 14 and a nut. To do.

The construction method of the front formwork using the PC board 1 is carried out according to the work flow shown in FIG.

Each work shown in FIG. 14 will be described below. (A) A work flow for manufacturing and installing the lower fixing device 5 is shown in FIG. The installation accuracy of the lower fixing device 5 determines the top height, tilt, and position of the PC board 1 placed on it, so the installation work should be carried out carefully so that it falls within the standard values based on the quay normal survey. In addition, when placing the chemical anchor 11 that is placed in the work flow, make sure that the drilling diameter, drilling depth, and curing time of the resin capsule are set according to the manufacturer's catalog. (Including selection). The PC plate lower pedestal 13 and the normal fixing jig 14 of the lower fixing device 5 are all buried in underwater concrete.

(B) Assembling and erection of the upper fixing device 6 is P
Prior to the installation of the C plate 1, the caisson on which the lower fixing device 5 has been installed is erected to receive the support for the conductive material, and the installation of 10 is preceded, followed by the support 9 for the conductive material and then the conductive material 8. Install with a truck crane. A member based on the normal survey of the quay wall will be installed together with the guide material support 9 and guide material 8.

At this time, the conductive material 8 to be installed along the existing caisson 3 is installed from a position several tens of centimeters away from the joint of the existing caisson 3 so as not to hinder the building of the gable form 2, Use a mountain clasp with a length that stops a few tens of centimeters before the caisson joint.

The guide material support 9 fixes the four corners of the giraffe jack with chevron steel so that the wave pressure (pushing wave) from the guide material 8 is evenly transmitted to the support 10 and the shaft core is fixed. So that it becomes a straight line, support it with a giraffe jack or a piece of mountain retaining material from the top of the existing caisson 3 hitting with water, and after adjusting the height, fix the feet with a hole-in anchor and fix it so that it does not move laterally. To do. The bracket 16 which supports the guide material support work and supports the uprising 10 is fixed to the concrete wall surface of the existing caisson 3 by the hole-in anchor 17.

At locations where the existing caisson 3 has a high water hitting tip and the brackets cannot be installed, a chemical anchor is placed, and an abdomen (a ready-made piece of mountain retaining material) is hung in the track lane. Chemical anchor from horizontal
Align the hole of the bellows with 11 and fix with the nut. A wooden camber is driven into the gap between the abdomen and the wall of the existing caisson so that the wave pressure (pushing wave) can be evenly transmitted to the concrete surface. After erection of the conductor supporting members 9 is completed, the upper portion of each conductor supporting member 9 is fixed by a horizontal joint material (angle steel) so that the wave pressure from an oblique direction and the conductor supporting member are not displaced.

FIG. 16 shows a work flow for erection and installation of the upper fixing device 6. Guide member 8 and guide member support 9 A stanchion is attached at the time of grounding and the main rope is stretched so that the safety belt can be used when the safety passage 12 of the above work flow is installed.

(C) The work flow for installing the PC board 1 is as described below. A) Unloading the PC board 1) Attaching a jig for installing the PC board to the head of the PC board 1 and an jig for unloading the legs. C) From the parent hook of the crawler crane to the PC on the PC board head
Hang the sling wire on the jig for plate installation and fasten it with the shackle. D) Then, hook the sling wire from the child hook of the crawler crane to the jig for unloading the PC board leg and fasten it with the shackle. E) While raising the PC board head slowly with the crawler crane, adjust the tension of the sling wire at the feet,
The board 1 is built vertically, and the lower part of the PC board 1 is placed on the scaffold board. F) In the state of e), remove the jig and sling wire for unloading the PC board legs. G) After the work of step f) is completed, insert the separator into the box for installing the separator and temporarily fix it with the nut in order to install the separator for the next work. C) After inserting the separator, suspend the PC board 1 with a crawler crane according to the diver's signal, and place it on the PC board lower pedestal 13 of the lower fixing device 5 already installed on the rubble mound of the seabed. (C) The PC board 1 placed on the lower PC board support 13 is moved to a predetermined position by mounting a lever block on the underwater anchor that has already been placed. (C) A steel camber is struck between the PC board 1 and the lower PC board 13 to fix the PC board 1. (A) Fix the PC board 1 and the conductive material 8 of the upper fixing device 6.

(D) Separator mounting When the installation of the PC board 1 is completed, the underwater anchor (chemical anchor with ring 1 attached with a ring is placed by the diver in the order of the lower separator and then the upper separator).
Fix it to 1) with a shackle, adjust the length of the separator 4 with a tan buckle or long nut (left, right screw type), and fix it with a predetermined length. At this time, the separator should be evenly tightened so that it does not work. Since the degree of tightening of the separator 4 affects the degree of lateral pressure applied to the concrete during pouring of underwater concrete, a dedicated diver is assigned to perform the task of tightening the separator. Figure 17 shows the work flow for installing the separator.

Since both the upper and lower separators 4 receive a pulling force of 5.5 to 5.9 ton per separator, when the underwater anchor for fixing the separator 4 is placed, the drilling diameter and the drilling depth are set. Now, place it so that the drilling pitch fits within the catalog data. In addition, the resin capsule of the underwater anchor should be managed so that it will be cured for at least one day.

Next, the installation of the gable form 2 will be described.
The gable form 2 is to be installed in the construction cross-section direction perpendicular to the PC board 1, and has four surfaces in the existing caisson 3 or the existing caisson 3 because of the work capacity and work efficiency of the mixer ship when pouring underwater concrete. Four caisson boxes will be installed.

As shown in FIG. 2, FIG. 3 and FIG. 11, the members forming the gable form 2 are a frame receiving material 18 and a frame receiving material 18 which are frame materials.
Horizontal splice material 19 for fixing, Breath material 20 used to prevent deformation of frame support material 18, Metal foam 2 to be inserted into frame support material 18
1. A guide 22 for supporting the frame support material 18 when it is installed and for preventing it from leaking concrete when pouring underwater concrete. A gap between the frame support material 18 and the existing caisson 3 side. It is composed of an iron plate 23 that closes the frame and a separator 24 that fixes the frame receiving members 19 at both ends of the caisson and resists underwater concrete.

The frame receiving member 18 is a member for supporting the separator 24 and the metal foam 21 inserted inside the frame receiving member 18, and should be within 1.5 m interval from the lateral pressure calculation of the underwater concrete depending on the width of the section to be installed. To install. The length of the frame receiving member 18 is from the maximum water depth to a height of 1 m from the top of the water-impregnated concrete of the existing caisson 3, and the installation interval of the frame receiving member 18 is
Since the metal foam 21 to be inserted inside the frame receiving material 18 is used vertically, the width is set to a width of 0.3 m.

A hole for a separator, a hole for fixing a built-in guide, and a hole for fixing an iron plate on the side of the existing caisson 3 are preliminarily drilled on the frame receiving member 18 on land. In particular, since the seabed ground changes with the holes for separators, the holes that are no longer used are covered with iron plates so that the cross-sectional performance is not degraded.

The horizontal joint material 19 uses H-section steel and channel steel,
It has a function of fixing the frame receiving member 18 and adjusting the interval of the frame receiving member 18 with bolts. It also receives the separator 24 installed on the frame receiving member 18, and also takes charge of reinforcing the frame receiving member 18.

The brace material 20 is used to prevent deformation of the frame support material 18, and is made of round bar steel and a tan buckle.

As the metal foam 21, 3015 coated with a ready-made face material is used, and the number of the metal foam 21 to be inserted into the frame receiving material 18 is increased or decreased according to the width of the frame receiving material 18. The metal foam 21 is used vertically, and each is fixed with a groove steel flapping material and L pins, and framed so that it can be hung by a crane and inserted. Further, rubber is attached to the frame receiving material side of the metal foam 21 so that the concrete does not leak.

The built-in guides 22 are angle steels installed on both sides of the cross section of the PC board 1 side and the existing caisson 3 side, and holes are preliminarily drilled on the land so that the PC board 1 side can be used when the PC board is installed. It is bolted using the insert embedded in the board 1 and installed with the PC board 1 as shown in FIG. The existing caisson 3 side is hung by a crane and fixed by a diver in the sea with a hole-in anchor. In addition,
The building guide 22 is embedded in underwater concrete,
Used as an expansion joint.

The iron plate 23 is for filling the gap between the frame receiving member 18 and the existing caisson 3 and has a thickness of 6 mm. The frame receiving member 18 is a bolt and the existing caisson 3 side is the above-mentioned guide for assembling.
Weld underwater to 22. After placing underwater concrete, frame receiving material 18
The bolts of the building guide 22 are cut, the iron plate 23 is buried in underwater concrete, and used as an expansion joint.

Two separators 24 are used in each of the upper and lower stages and one frame receiving material according to the lateral pressure calculation result of underwater concrete. The members constituting the separator 24 are divided into two members at both ends and two members in the middle and temporarily placed on the separator 11 for easy installation when the PC board 1 is installed. Sometimes joined by a diver.

The length of the separator 24 can be adjusted with a tan buckle so that it can follow the length of the existing caisson 3.
Use a combination of right and left screws to prevent the other from loosening when tightening one. A long nut is used for the connection portion with the frame receiving member 18 so that the separator 24 can be easily removed when the end mold 2 is released from the mold.

The method of constructing the gable form 2 is carried out by the work flow shown in FIG. 18 after the PC board 1 is installed.

To describe each work, in the (A) cross-section measurement, after the PC board 1 is installed, a diver measures the cross-sectional shape of the gable formwork installation portion.

(B) In the ground work of the gable form member, according to the result of (A), the frame receiving material 18 is arranged on land, the horizontal joint material 19 is fixed with a predetermined width, and the frame receiving material 18 is fixed. We connect each other with breath material 20. A hole is formed in the frame receiving material 18 at the position of the separator 24 with gas.

(C) When installing the installation guide (on the existing caisson side), since the PC board 1 side is installed using the insert of the PC board 1 when installing the PC board, the installation on the existing caisson 3 side is performed. The guide 22 is suspended by a crane, and a diver attaches a hole-in anchor to the wall of the existing caisson 3.

(D) Build the gable form 2 as described in (B) above.
The gable formwork 2 which has been grounded in step 1 is hung on each side by a crane, unloaded by a diver into the sea, and fixed with the building guide 22 (C) and the bolt. For fine adjustment of the frame orientation,
Place the lever block on the frame support 18 and install the guide 22
And face.

(E) Tightening of the separator. After the double-sided gable formwork 2 has been built in (D), the separator 24, which was temporarily placed in the sea when the PC board was installed, was connected in the sea by a diver, and the frame receiving materials 18 were joined together. Tie at 24 and get tight.

(F) Iron plate installation. After the work of (E) is finished, the iron plate 23, which has been processed on land based on the cross-section measurement of (A) in advance, is hung by a crane and installed by the diver in the sea with the frame support material 18. To guide guide 22. The frame support 18 and the iron plate 23 are bolts, and the building guide 22 and the iron plate
23 is fixed by underwater welding.

(G) Insertion of metal foam. Prior to underwater concrete pouring, a metal foam 21, which has been frame-assembled on land in advance, is hung by a crane and inserted between the frame supports 18. The metal foam 21 is inserted immediately before pouring the underwater concrete so that the PC plate of the front formwork is not affected by the wave pressure as much as possible.

When pouring the underwater concrete, the pouring speed is strictly observed based on the calculation of the lateral pressure of the concrete, the concrete uplift surface is measured with red during the pouring of the concrete, and the tip of the concrete discharge port is always in the concrete. Perform construction management as described in.

Also, pay sufficient attention to the displacement of the upper separator 4, and if the ring portion of the upper chemical anchor 11 with a ring that fixes the PC plate 1 extends, take measures such as temporarily suspending the concrete pouring. I do. During pouring of underwater concrete, a diver checks whether concrete is leaking or whether the PC board 1 or the gable form 2 is deformed. For underwater concrete, the start time for placing concrete is selected so that the surface of the concrete that has been launched is not washed with seawater and that the finish of the concrete is completed during the low tide time.

[0064]

As described above, in the underwater formwork construction method of the present invention, by using the PC board and the underwater anchor together, the PC board becomes a formwork material for the underwater formwork during construction, and after construction, the structure is constructed. Become a part. Therefore, the amount of underwater concrete and the amount of rebar as a structure can be reduced, and since the cross-sectional performance of the PC plate is excellent, there is an advantage that a large number of separators are not required when constructing an underwater form.

Therefore, compared with the conventional method, the work of a diver in the sea such as the installation of the separator and the assembly of the underwater rebar can be reduced and the cost can be reduced, and the PC board can be used as a part of the structure in the underwater concrete. Since the mold is buried, it is not necessary to remove the mold after placing concrete, unlike the conventional underwater mold, and it is possible to significantly shorten the process.

Also, in the construction of the gable form using H-section steel, metal foam, and iron plate in combination, it is not necessary to process the gable form in response to changes in the cross section where the form is installed, and the grate receiving material is used. It can be handled simply by changing the mounting interval of
Moreover, there is an advantage that the separator of the gable form can be used as a submersible rebar. In particular, if you can expect the bearing capacity of the seabed, by reducing the number of installation locations of the gable formwork,
The underwater formwork method is most suitable for rapid construction.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional side view of essential parts showing an embodiment of an underwater formwork method of the present invention.

FIG. 2 is a sectional view of a gable form part showing an embodiment of the underwater form forming method of the present invention.

FIG. 3 is an overall plan view showing an embodiment of the underwater formwork method of the present invention.

FIG. 4 is a front view of a PC board.

FIG. 5 is a plan view of a joint portion of a PC board.

FIG. 6 is a side view showing details of the upper fixing device.

FIG. 7 is a plan view showing details of the upper fixing device.

FIG. 8 is a side view showing details of the lower fixing device.

9 is a detailed view of a portion A in FIG.

FIG. 10 is a plan view of a separator.

FIG. 11 is a plan view of the main part of the gable formwork.

FIG. 12 is a cross-sectional view showing the middle of installation of the gable formwork.

FIG. 13 is a sectional view of a separator.

FIG. 14 is a flowchart showing a work flow of the present invention.

FIG. 15 is a flowchart showing manufacturing and installation of a lower fixing device.

FIG. 16 is a flow diagram showing a work flow of grounding and erection of the upper fixing device.

FIG. 17 is a flowchart showing the work of attaching the separator.

FIG. 18 is a flowchart showing a method of constructing a gable form.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... PC board 1a ... Recessed part 1b ... Convex part 2 ... Wife form 3 ... Existing caisson 4 ... Separator 4a ... Anchor part 5 ... Lower fixing device 6 ... Upper fixing device 7 ... Anchor 8 ... Conductor 8a ... Bracket 9 ... Guide Material support 10… Guide material support upset 11… Chemical anchors 12… Scaffolding for PC board installation (also serves as scaffolding for superstructure work formwork) 13… PC board lower support 14… Fixing normal Tool 15… Concrete 16… Bracket 17… Hole-in anchor 18… Frame support 19… Horizontal joint material 20… Pressed material 21… Metal foam 22… Installation guide 23… Steel plate 24… Separator 25… Conductor material Support cradle 26 ... Underwater anchor (shear reinforcement)

Front page continuation (72) Inventor Teruo Maehara 1-3-15 Awaza, Nishi-ku, Osaka City, Osaka Prefecture Kashima Construction Co., Ltd., Kansai Branch (72) Inventor Tatsuo Suzuki 35, Nishimachi, Chuo-ku, Kobe City, Hyogo Prefecture Obayashi Corporation Kobe branch (72) Inventor Kakimi Toshiwa Ohibayashi 1-10-19 Higashi Sakura, Higashi-ku, Nagoya, Aichi Prefecture Incorporated company Nagoya branch (72) Inventor Shuji Uchimura 2-5-8 Kita-Aoyama, Minato-ku, Tokyo (72) Inventor Shinji Okumura 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Inside Makumagumi Co., Ltd. (56) References JP-A-6-306832 (JP, A) JP-A-8-92936 (JP, A) Actual Publication 63-11260 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) E02B 3/06

Claims (2)

(57) [Claims] 1. A chemical anchor is preliminarily placed on the concrete surface of an existing caisson as an existing revetment, and then a lower fixing device consisting of a PC plate lower pedestal and a normal fixing jig is attached to the seabed. installation, installation in the sea put the PC board to be used as a part of the front surface mold as prestress those manufactured by introducing in water formwork and structure of the present set to the lower fixing device, on top of the PC board Install the guide material of the upper fixing device, support it from the land side by earth retaining support, connect to the chemical anchor, and adjust the length with a tan buckle or long nut. An existing casing for the upper and lower sides of the PC plate and the existing revetment as the existing revetment with a separator with a reduced number of members that can follow changes in length and that will not cause problems in durability even if bending stress is applied. Of a chemical anchor was Da設 the concrete surface was Tightened, after assembly of the wife formwork, water concrete was Da設, water formwork construction method characterized in that demolding wife formwork. 2. The underwater mold construction method according to claim 1, wherein the gable form is made of a frame receiving material that is a frame material, a horizontal joint material that fixes the frame receiving material, and a metal foam that is inserted into the frame receiving material.