JP2014058793A - Construction method of dike utilizing multi-purpose post and construction method of wall body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a dike with which a permanent form can be accurately installed and workability can be improved.SOLUTION: A construction method of a dike utilizing a multi-purpose post 3 rising from an existent concrete wall part 1includes: a permanent form installation step of erecting a new permanent form 2on an existent permanent form 2left on one side face of the existent concrete wall part 1and supporting the new permanent form 2with the multi-purpose post 3; a scaffold installation step of installing a scaffold unit 4 on the other side face of the existent concrete wall part 1and supporting the scaffold unit 4 with the multi-purpose post 3; and an installation step of installing concrete at an upper side of the existent concrete wall part 1.

Description

  The present invention relates to a construction method of a breakwater using a multipurpose post, and further relates to a construction method of a wall body using a support.

  As a method of constructing a breakwater (wall body) such as an above-ground LNG tank or an underground LNG tank, an inner mold (such as a steel liner plate or a precast concrete segment) is installed at a position that becomes the inner peripheral surface of the wall body. In addition, a method is known in which an outer mold is installed at a position that becomes the outer peripheral surface of the wall body, and concrete is placed between the inner mold and the outer mold (for example, see Patent Documents 1 to 3). . The inner mold is a so-called remaining mold and is left as it is after the concrete is hardened.

  In addition, as a method of constructing the wall of an underground LNG tank, a method is also known in which a residual mold is installed facing the underground continuous wall, and concrete is placed between the residual mold and the underground continuous wall. (For example, see Patent Document 4).

  Since the height of the wall body may reach several tens of meters, when the wall body is started up, it is general that the wall body is started up in several lots divided into a plurality of lots.

JP-A-5-196029 JP 7-286449 A JP 2010-106501 A Japanese Patent Laid-Open No. 8-120697

  In each lot, it is necessary to perform the work of installing the new remaining formwork on the existing remaining formwork left in the previous lot, but in order to position the new remaining formwork, Since it is necessary to hang the water thread after setting the remaining formwork on the outside, etc., it takes time and effort. Also, between the remaining mold and the outer mold, etc., it is necessary to arrange a large number of separators so as to withstand the concrete side pressure (see Patent Documents 1 and 4). Installation work takes time and may hinder work performed between the molds.

  From such a point of view, the present invention provides a method for constructing a breakwater and a method for constructing a wall body that can easily and accurately install a remaining formwork and can improve workability. Is an issue.

  A construction method of a breakwater according to the present invention that solves the above problem is a construction method of a breakwater using a multipurpose post that stands up from an existing concrete wall, and is left on one side of the existing concrete wall. A new remaining formwork is erected on the existing remaining formwork, a remaining formwork installation process for supporting the new remaining formwork with the multipurpose post, and a scaffold unit is installed on the other side of the existing concrete wall. And a scaffold installation step of supporting the scaffold unit with the multipurpose post, and a placement step of placing concrete on the upper side of the existing concrete wall.

  In short, the present invention is to support the new remaining formwork and the scaffold unit with the multipurpose post rising from the existing concrete wall, and perform the placing process in such a state. According to the present invention, since the new remaining formwork can be positioned using the multipurpose post, the new remaining formwork can be installed with high accuracy without using a relief or water thread. In addition, since the horizontal force generated in the new residual formwork due to the side pressure of the concrete acts on the multipurpose post, even if the number of separators is reduced or omitted, the new residual formwork is prevented from falling or deforming. be able to. In the past, it was necessary to fix the formwork with a large number of separators, which required time and labor. However, if the number of separators could be reduced or omitted, the installation work of the separator would be simplified or unnecessary, and the space between the formwork Since the worker can easily move, various operations performed in the space can be performed efficiently. In addition, the new residual formwork can be erected on the existing residual formwork only from the back side (concrete side) of the new residual formwork. It is also possible to omit or simplify the scaffold.

  Moreover, since it becomes possible to multiplex the fall prevention measures of a scaffold unit, it becomes possible to improve the safety | security of an aerial work.

  In the remaining mold installation step, the new residual mold is supported by the multipurpose post by interposing a support member between the new residual mold and the multipurpose post, and in the placing process, the support It is advisable to cast concrete to a position lower than the member. In this way, since the support member is not buried, it is possible to remove the support member and use it for the next lot, thereby reducing the cost.

  It is preferable to lay concrete pressure feed pipes on a plurality of the multipurpose posts and to cast concrete using the concrete pressure feed pipes. If it does in this way, as a result of preventing a concrete pumping pipe from being arranged irregularly, work space comes to be organized, and workability is further improved.

  In the case of arranging a wall bar on the upper side of the existing concrete wall part, the wall bar may be supported by the multipurpose post. If it does in this way, it will become possible to prevent the position gap of the wall reinforcement at the time of concrete placement.

  When prestress is introduced into the wall body, PC steel material may be horizontally mounted on the plurality of multipurpose posts. If it does in this way, since the installation work of PC steel materials will become easy, even if it is a case where a wall body is made into PC structure, it becomes possible to improve workability.

  In the method for constructing a wall body according to the present invention for solving the above-mentioned problem, a new residual mold is erected on an existing residual mold left on one side of an existing concrete wall, It includes a remaining mold installation process for supporting the newly installed residual mold with standing uprights, and a placing process for placing concrete on the upper side of the existing concrete wall. In addition, a support | pillar may be used only for support of a newly established formwork, and may be used for multiple purposes like the construction method of a breakwater.

  According to the method for constructing a wall body according to the present invention, it is possible to accurately install the newly installed remaining formwork. Further, even if the number of separators is reduced or omitted, it is possible to prevent the newly formed remaining formwork from falling over and deforming. If the number of separators can be reduced or omitted, the installation work of the separators can be saved or unnecessary, and the worker can easily move through the space between the molds, so that various operations performed in the spaces can be performed efficiently. It becomes. In addition, the new residual formwork can be erected on the existing residual formwork only from the back side (concrete side) of the new residual formwork. It is also possible to omit or simplify the scaffold.

  According to the present invention, it is possible to improve the workability when building a breakwater or a wall divided into a plurality of lots, and it is possible to accurately install a new remaining formwork.

(A) is sectional drawing which shows the structure of a wall body, (b) is the lower part enlarged view of (a). It is the sectional view on the AA line of (b) of FIG. It is sectional drawing which shows the state which the concrete placement of the n-1st lot was completed. It is sectional drawing for demonstrating the post extension process in the nth lot, and a residual mold installation process. It is sectional drawing for demonstrating the bar arrangement process and PC steel material arrangement | positioning process in the n-th lot. It is sectional drawing for demonstrating the scaffold installation process and placement preparation process in the n-th lot. It is sectional drawing for demonstrating the placement process in the nth lot. (A) is a plan view showing a state in which the remaining formwork installation process, bar arrangement process and PC steel material arrangement process in the n-th lot are completed, and (b) shows a state in which the placement preparation process in the n-th lot is completed. FIG.

  The wall body W according to the embodiment of the present invention is a liquid barrier of a ground LNG tank, and has a cylindrical shape in plan view, although illustration is omitted.

  As shown in FIG. 1A, the wall body W is a prestressed concrete structure that rises from the bottom slab B, and is left on the concrete wall portion 1 made of cast-in-place concrete and the inner surface of the concrete wall portion 1. The remaining mold 2 and a multipurpose post (post) 3 embedded in the concrete wall 1 are provided.

  As shown in FIG. 1B, in addition to the wall bars 1a and 1a, a circumferential PC steel material 1b, a longitudinal PC steel material, and the like are embedded in the concrete wall portion 1. The wall stripe 1a is a combination of vertical and horizontal stripes in a grid pattern. The circumferential direction PC steel material 1b is made of a PC steel wire extending from one pilaster to another pilaster, and is inserted into a sheath 1c (hereinafter referred to as “lateral sheath 1c”) extending in the circumferential direction. The transverse sheath 1c is arranged along the wall bars 1a on the outer peripheral side (opposite side of the remaining mold 2 with the multipurpose post 3 in between). The longitudinal PC steel material is composed of a PC steel rod extending from the lower end portion to the upper end portion of the concrete wall portion 1 and is inserted through a sheath 1d extending in the vertical direction (hereinafter referred to as “vertical sheath 1d”).

  The remaining mold 2 is formed by connecting a plurality of segments in the circumferential direction and the vertical direction. The segment is a precast concrete product having a rectangular shape in front view and an arc shape in plan view. Although illustration is omitted, in addition to the joint box opening to the concrete wall 1 side, the segment is integrated with the insert nut for the outer tank liner plate, the insert nut for the separator, and the concrete wall 1. A shear transmission member or the like is embedded.

  The multipurpose post 3 is disposed between the wall bars 1a and 1a. The multipurpose post 3 is provided with a rigidity capable of supporting itself even in the absence of concrete. The lower end portion of the multipurpose post 3 is embedded in the bottom plate B.

  As shown in FIG. 2, a plurality of multipurpose posts 3 are arranged in parallel at intervals in the circumferential direction (horizontal direction) of the wall body W. The multipurpose posts 3, 3,... Are arranged in the center portion of the concrete wall portion 1 in the wall thickness direction. Although the multipurpose post 3 of this embodiment consists of H-section steel, it may replace with H-section steel and may use I-section steel, C-section steel, a steel pipe, etc. Although there are no restrictions on the installation interval and position of the multipurpose posts 3, 3,..., In this embodiment, half of the circumferential length of the segments constituting the remaining mold 2 is set as the installation interval of the multipurpose posts 3, 3,. In addition, the multipurpose post 3 is opposed to the joint J between the segments.

When the wall body W is constructed, it is divided into n lots (n is an integer of 2 or more) times and is started up by several m. Although not shown, in the first lot, the remaining mold 2 is supported using the multipurpose post 3 (see FIG. 1B) rising from the bottom plate B, and the bottom plate is used using the remaining mold 2. The lowermost layer portion of the concrete wall portion 1 is formed on B. In each lot after the second time, as shown in FIGS. 3 to 7, predetermined lots are formed on the existing parts (existing concrete wall part 1 _n-1 and existing residual formwork 2 _n-1 ) formed in the previous lot. A new height part (new concrete wall 1 _n and new remaining formwork 2 _n ) is formed.

The “existing concrete wall portion 1 _n-1 ” and the “existing remaining formwork 2 _n-1 ” are formed in the previous (n−1) th lot of the concrete wall portion 1 and the remaining formwork 2. The “new concrete wall portion 1 _n ” and the “new residual formwork 2 _n ” refer to portions formed in the current (n-th) lot. The subscript attached to the code corresponds to the number of lots.

FIG. 3 is a diagram showing a state where the concrete placement in the (n-1) th lot is completed.
The wall bars 1a, 1a, the longitudinal sheath 1d (longitudinal direction PC steel), and the multipurpose post 3 protrude from the upper end surface of the concrete (existing concrete wall portion 1 _n-1 ) placed in the _n- 1th lot. . The existing remaining formwork 2 _n-1 extends upward from the upper end of the existing concrete wall 1 _n-1 and serves as a fall prevention fence for the next lot work. In addition, an insert nut 1e for fixing the scaffold unit 4 is embedded at an appropriate position of the existing concrete wall 1 _n-1 .

  Although there is no restriction | limiting in the structure of the scaffold unit 4, the thing of this embodiment is a work scaffold with a formwork, while supporting the outer formwork 41 and the outer formwork 41 which shape | mold the outer surface of the concrete wall part 1. A lower scaffolding plate 42 that serves as a work floor, a support girder 43 that supports the lower scaffolding plate 42 from below, a bracket 44 that supports the support girder 43 from below, an upper scaffolding plate 45 supported on the upper part of the outer frame 41, etc. It has. The outer mold frame 41 is slidable in the inner and outer directions of the wall body W (left and right direction in the drawing). The scaffold unit 4 is supported by the multipurpose post 3 via the connecting member 5.

  The connecting member 5 contributes to preventing the scaffold unit 4 from falling and is stretched between the multipurpose post 3 and the scaffold unit 4 without slack. Although the connection member 5 of this embodiment consists of a steel cable (wire rope), a steel wire, a shape steel, etc. may be sufficient. Although there is no restriction | limiting in the number and position of the connection member 5, in this embodiment, the upper end part of the multipurpose post 3 and the upper end part of the outer mold frame 41 are connected so that it may not become obstructive when performing another process. . In addition, although illustration is abbreviate | omitted, you may connect the upper end part of the multipurpose post 3, and the lower stage scaffolding board 42 grade | etc.,. In the present embodiment, one connecting member 5 is arranged for one multipurpose post 3, but a plurality of connecting members 5 may be arranged for one multipurpose post 3.

  Since the main work procedure in each lot after the second lot is the same, the work procedure in the n-th lot will be described in detail below.

  The n-th lot includes a post extension process, a remaining mold installation process, a bar arrangement process, a PC steel material arrangement process, a scaffold installation process, a placement preparation process, and a placement process.

The post extension step is a step of extending the multipurpose post 3 upward as shown in FIG. In the present embodiment, in order to shorten the work period, the post extension process is performed before the concrete of the previous lot reaches the demolding strength (before the outer frame 41 is demolded). This is carried out using the upper stage scaffold plate 45 of the scaffold unit 4 fixed to the existing concrete wall 1 _n-2 . In order to extend the multipurpose post 3, an H-shaped steel (a member constituting the multipurpose post 3) may be added to the upper end of the multipurpose post 3 protruding from the existing concrete wall 1 _n-1 . The length of the H-shaped steel to be added is equal to or more than the height of the wall body W that rises in one lot so that the upper end of the extended multipurpose post 3 is positioned above the newly formed residual form 2 _n . In addition, when making the length of the H-shaped steel to be added equal to the height of the wall body W rising in a plurality of lots, it is not necessary to perform the post extension process in each lot, and the multipurpose post 3 is extended in each lot. Can be done.

The remaining mold installation process is a process in which the new remaining mold 2 _n is erected on the existing remaining mold 2 _n-1 and the newly installed remaining mold 2 _n is supported by the extended multipurpose post 3. Similar to the post extension step, the remaining mold installation step is performed using the upper scaffold plate 45 of the scaffold unit 4 fixed to the existing concrete wall 1 _n-2 . In the remaining mold installation step, the new residual mold 2 _n is supported by the multipurpose post 3 by interposing a support member 6 between the new residual mold 2 _n and the multipurpose post 3. As the support member 6, the one used in the previous lot (see FIG. 3) is diverted.

In the remaining formwork installation step, first, a segment to be the new remaining formwork 2 _n is suspended by a crane (not shown) and placed on the upper end surface of the existing remaining formwork 2 _n-1 . At this time, the installation position of the new remaining mold _2n is confirmed by measuring the offset amount from the multipurpose post 3, and the installation position of the new remaining mold _2n is adjusted as necessary. Next, using the joint box (not shown) provided in each segment, the segment to be the new remaining mold _2n is bolted to the existing remaining mold _2n-1, and the other adjacent ones in the circumferential direction are joined. Bolt to the segment. Thereafter, the newly formed remaining form 2 _n and the multipurpose post 3 are connected by the support member 6. As shown in FIG. 8A, two support members 6 are arranged on the multipurpose post 3 facing the joint J between the segments adjacent in the circumferential direction, corresponding to the two segments.

The support member 6 contributes to prevention of displacement and tilting of the new remaining mold 2 _n and is used until the concrete 9 (see FIG. 7) reaches a predetermined strength (for example, demolding strength). The support member 6 of this embodiment consists of a shape steel. The material and strength of the support member 6 are not limited, but if the support member 6 is a member that can resist not only the tensile force but also the compressive force, the direction in which the new remaining mold 2 _n moves away from the multipurpose post 3 (FIG. 4). In addition, it is possible to prevent the newly formed mold 2 _n from falling in the direction approaching the multipurpose post 3 (leftward in FIG. 4). As shown in FIG. 5, in this embodiment, the support member 6 is arranged at the upper end of the newly formed mold 2 _n so that the support member 6 is not buried in the concrete 9 (see FIG. 7). In addition, although illustration is abbreviate | omitted, when making the support member 6 disposable, you may arrange | position the support member 6 in the position buried in the concrete 9 (refer FIG. 7).

As shown in FIG. 5, the bar arrangement process is a process in which wall bars 1 a and 1 a are arranged above the existing concrete wall portion 1 _n-1 and the wall bars 1 a and 1 a are supported by the multipurpose post 3. The installation position of the wall reinforcement 1a is confirmed by measuring the offset amount from the multipurpose post 3. The wall bars 1a and 1a are fixed to the multipurpose post 3 by using a not-shown wire or the like. The lower end of the new wall reinforcement 1a is connected to the existing wall reinforcement 1a, 1a protruding from the existing concrete wall 1 _n-1 through an appropriate reinforcing steel joint (lap joint, mechanical joint, etc.). The wall reinforcement 1a may be assembled at a reinforcing bar processing site in the construction site and built in a state of a reinforcing bar net or a reinforcing bar rod. In the present embodiment, since the reinforcing bar is arranged with the scaffold unit 4 fixed to the existing concrete wall 1 _n-2 , the outer frame 41 becomes an obstacle when the reinforcing bar net or the reinforcing bar is installed. Therefore, the bar arrangement work can be performed smoothly. Needless to say, the wall bars 1a and 1a may be formed by combining reinforcing bars on the upper side of the existing concrete wall 1 _n-1 .

  The PC steel material arranging step is a step of horizontally laying the circumferential PC steel material 1b on a plurality of multipurpose posts 3, 3,... (See FIG. 8A). The circumferential PC steel material 1b is arranged in a state of being inserted through the transverse sheath 1c. The transverse sheath 1c (circumferential PC steel material 1b) is disposed along the outer wall reinforcement 1a (see FIG. 8A) and fixed to the flange of each multipurpose post 3 using a U-bolt or the like (not shown). . A fixing tool fixed to a pilaster (not shown) is attached to the end of the circumferential PC steel material 1b. In addition, there is no restriction | limiting in the attachment method to the multipurpose post 3 of the horizontal sheath 1c, You may bind to each multipurpose post 3 by a number line etc., and you may mount on the bracket overhanging from the multipurpose post 3.

Further, in the PC steel material arranging step, the longitudinal PC steel material is arranged above the existing concrete wall 1 _n-1 . The longitudinal PC steel is arranged in a state of being inserted through the longitudinal sheath 1d, and the lower end of the longitudinal PC steel is provided with an appropriate mechanical joint on the existing longitudinal PC steel protruding from the existing concrete wall 1 _n-1. Connect through. The installation position of the vertical sheath 1d is confirmed by measuring the offset amount from the multipurpose post 3.

As shown in FIG. 6, the scaffold installation step is a step of installing the scaffold unit 4 on the outer surface of the existing concrete wall portion 1 _n-1 and supporting the scaffold unit 4 with the extended multipurpose post 3.

In the scaffold installation step, first, the outer mold frame 41 is slid to be removed from the existing concrete wall 1 _{n-2 at the (n−2) th} stage. Next, the scaffold unit 4 fixed to the existing concrete wall portion 1 _n-2 at the n-2 stage is suspended by a crane (not shown), and the scaffold unit 4 is removed from the existing concrete wall portion 1 _{n-2 in} this state. After removal, the scaffold unit 4 is pulled up to the side of the existing concrete wall portion 1 _{n-1 at} the ( _n- 1) _th stage, to the side of the planned construction position (the planned placement position of concrete) of the new concrete wall portion 1 _n The outer mold 41 is positioned. After raising the scaffold unit 4 to the side of the n-1 stage existing concrete wall 1 _n-1 , the upper end of the bracket 44 is screwed into the insert nut 1 e so that the upper end of the bracket 44 is installed in the existing concrete wall 1 _{n−. 1} and the lower end of the bracket 44 is abutted against the outer surface of the existing concrete wall 1 _n-1 . Thereafter, the multipurpose post 3 and the scaffold unit 4 are connected by the connecting member 5. The connection position between the multipurpose post 3 and the connecting member 5 is preferably higher than the connection position between the scaffold unit 4 and the connecting member 5.

The placing preparation process is a process in which the concrete pressure-feed pipe 7 is horizontally mounted on the multipurpose posts 3, 3,. The concrete pumping pipe 7 extends along the circumferential direction (lateral direction) of the wall body W (see FIG. 8B). The concrete pumping pipe 7 is disposed at a position where it is not buried in the new concrete wall 1 _n (in this embodiment, the upper end of the multipurpose post 3), and is fixed to the multipurpose post 3 by U bolts, wire numbers, etc. (not shown). . Note that a branch pipe (not shown) is connected to the concrete pumping pipe 7. The branch pipe extends downward from the concrete pumping pipe 7. An open / close valve is interposed in the branch pipe.

In the placing preparation process, the outer mold 41 is installed at a position that becomes the outer surface of the new concrete wall 1 _n , and if necessary, the upper part of the existing remaining mold 2 _n-1 and the outside The mold 41 is connected with the separator 8, and the new remaining mold 2 _n and the outer mold 41 are connected with the separator 8. In order to install the outer mold 41, the outer mold 41 may be slid toward the new remaining mold _2n . FIG. 6 shows a state where the installation work of the outer mold 41 is completed. When the connecting member 5 is slack, the connecting member 5 is shortened to ensure a state without any slack. The number of separators 8 may be a small number compared to the conventional method.

The placing step is a step of placing concrete 9 on the upper side of the existing concrete wall 1 _n-1 as shown in FIG. In the placing process, the concrete 9 is pumped using the concrete pumping pipe 7 and a branch pipe (not shown), and the concrete 9 is driven to a position lower than the top end of the outer mold 41 (a position lower than the support member 6). Set up.

Incidentally, at the time when the pouring process of the n lot is completed, the wall muscle 1a, 1a, the vertical sheath 1d (vertical direction PC steel) and multi-purpose post 3 is striking passage surface of the concrete 9 (on the new concrete wall 1 _n Projecting from the end face), and the newly remaining mold 2 _n extends above the joining surface of the concrete 9.

When the placing process is completed, the concrete pumping pipe 7 is removed, and when the concrete 9 reaches a predetermined strength, the support member 6 is removed and the outer mold 41 is removed (in the direction away from the new remaining form 2 _n) 41) to move to the next lot. The connecting member 5, the supporting member 6, and the concrete pressure feeding pipe 7 are reused in the next lot.

  When all the lots are completed, a tensile force is applied to the circumferential direction PC steel material 1b and the longitudinal direction PC steel material, and prestress is introduced to the wall body W.

Thus, according to the construction method of the wall body W (construction method of the breakwater) according to the present embodiment, the new remaining formwork 2 _n can be installed easily and accurately, and the multipurpose post 3 is used. Therefore, the workability is improved in a plurality of processes, and as a result, the construction period can be shortened.

More specifically, in the construction method of the wall body W according to the present embodiment, the newly formed remaining mold 2 _n can be supported by the multipurpose post 3 immediately after the newly installed remaining mold 2 _n is built, and the multipurpose post 3 _n can be supported. By adjusting the distance from the post 3, it is possible to position the new remaining mold _2n. Therefore, if the multipurpose post 3 is installed with high accuracy, the new remaining mold _2n can be installed with high accuracy. it can. By the way, in the past, the remaining formwork and wall streaks were positioned by hanging the water thread after setting the remaining formwork and wall streaks, etc. Such work requires time and effort. On the other hand, according to the construction method of the wall body W according to the present embodiment, the positioning accuracy of the newly formed remaining formwork 2 _n , the wall reinforcement 1a, and the like can be managed by measuring the offset amount from the multipurpose post 3. Not only can accuracy be improved, but also labor can be saved.

In addition, since the newly formed mold 2 _n is supported by the multipurpose post 3 at the time of placing the concrete, the horizontal force generated in the new remaining mold 2 _n by the side pressure of the concrete acts on the multipurpose post 3. Since the multipurpose post 3 is sufficiently embedded in the existing concrete wall 1 _n-1 , the inclination generated in the multipurpose post 3 becomes slight. Therefore, even if the number of separators 8 is reduced, It is possible to prevent the frame 2 _n from falling or deforming. Conventionally, it has been necessary to fix the formwork with a large number of separators, which requires labor. However, if the number of separators 8 can be reduced, installation work for the separators 8 can be simplified or unnecessary, and the space between the formwork can be reduced. Since the worker can easily move, various operations performed in the space can be performed efficiently.

  In addition, since the scaffold unit 4 is supported by the multipurpose post 3, it is possible to multiplex the fall prevention measures for the scaffold unit 4, and thus it is possible to increase the safety of work at high places.

  Furthermore, since the wall reinforcement 1a is supported by the multipurpose post 3, it is possible to prevent the positional deviation of the wall reinforcement 1a when placing concrete. Conventionally, it has been necessary to install a single pipe so as to straddle the scaffolding and formwork, and to support the wall reinforcement 1a with the single pipe, but if a multipurpose post 3 is used, a single pipe is installed. Even if it does not, since the wall reinforcement 1a can be positioned, labor saving can be achieved.

  In addition, since the circumferential PC steel material 1b (transverse sheath 1c) is horizontally mounted on the multipurpose posts 3, 3,..., The circumferential PC steel material 1b is compared with the conventional method in which a single pipe or the like is frequently used. Installation work becomes easy, and as a result, workability can be improved.

  Further, since the concrete pressure-feed pipe 7 is horizontally mounted on the plurality of multipurpose posts 3, 3,..., The concrete pressure-feed pipe 7 is prevented from being randomly arranged, and the work space is arranged and organized. That is, since the working environment at the time of placing concrete becomes favorable, the workability is further improved.

Moreover, according to the construction method of the wall body W according to the present embodiment, since the new remaining mold _2n is supported by the multipurpose post 3, the new remaining mold _{2n from} the back side (the scaffold unit 4 side) is supported. working alone, it can be erected new residual formwork 2 _n to the existing residual mold 2 _n-1, therefore, omitted or simplified formwork shoring or scaffolding to be installed in new residual mold 2 _n-side Can be realized. If the formwork support and scaffolding on the new remaining formwork _2n side can be omitted, the inside of the wall W can be opened after the end of the first lot. (For example, an operation of attaching a steel outer tank liner to the inner wall surface of the remaining mold 2, an operation of constructing an inner tank, etc.) can also be performed. If the start time of the machine work can be advanced, the entire construction period of the LNG tank can be shortened.

  Moreover, according to the construction method of the wall body W according to the present embodiment, the number of separators 8 can be reduced, and the cost can be reduced because the support member 6 and the concrete pumping pipe 7 can be removed and used for the next lot. Can be achieved.

  In addition, in this embodiment, although the case where the wall body W is a breakwater of a ground LNG tank was illustrated, it is not the meaning which limits the application range of this invention. Although illustration is omitted, the present invention can be applied to a wall of a tower structure in addition to a wall of an underground LNG tank.

  In this embodiment, although the case where the segment which comprises the residual formwork 2 was a precast concrete product was illustrated, the segment made from steel may be used. Moreover, you may form the residual formwork 2 using the segment by which the outer tank liner plate was affixed previously.

  The multipurpose post 3 may be temporary or may be used as a main structure. Moreover, although the case where the lower end part of the multipurpose post 3 was rooted in the bottom plate B was illustrated in this embodiment, the multipurpose post 3 may be erected on the upper surface of the bottom plate B.

  Moreover, although the case where the scaffold unit 4 (outer mold 41) is used is illustrated in the present embodiment, the remaining mold is installed facing the underground continuous wall, and the underground continuous wall is used as the outer mold. When doing so, the scaffold unit 4 (outer mold 41) may be omitted.

  In this embodiment, the case where three support members 6 are arranged for each segment constituting the remaining mold 2 is illustrated (see FIG. 8A), but the support members are provided at two left and right positions of each segment. Even if 6 is arranged, each segment can be sufficiently supported.

  Moreover, although the case where the separator 8 was used together was illustrated in this embodiment, the separator 8 may be omitted. In this way, the workability of the wall body W is further improved.

  In the present embodiment, the post extension process, the remaining formwork installation process, the bar arrangement process, and the PC steel material arrangement process are illustrated before performing the scaffold installation process. You may change suitably according to an intensity | strength expression condition, the use condition of a crane, etc. For example, although a detailed description is omitted, after the scaffold installation process, a post extension process, a remaining mold installation process, a bar arrangement process, and a PC steel material arrangement process may be performed. Moreover, you may change suitably the order of a residual mold installation process, a bar arrangement process, PC steel material arrangement | positioning process, and a placement preparation process.

W Wall 1 Concrete wall 1 _n-1 Existing concrete wall 1 _n New concrete wall 1a Wall reinforcement 1b Circumferential PC steel 1c Transverse sheath 2 Residual mold 2 _n-1 , 2 _n-2 Existing residual mold 2 _nNew remaining formwork 3 Multipurpose post (post)
4 Scaffolding unit 41 Outer form 5 Connection member 6 Support member 7 Concrete pumping pipe 8 Separator 9 Concrete B Bottom plate

Claims (6)

A method of constructing a breakwater using a multipurpose post that stands up from an existing concrete wall,
A residual mold installation step of standing a new residual mold on an existing residual mold left on one side of the existing concrete wall, and supporting the new residual mold with the multipurpose post;
Installing a scaffold unit on the other side of the existing concrete wall, and supporting the scaffold unit with the multipurpose post;
A method for constructing a breakwater using a multipurpose post, comprising a placing step of placing concrete on an upper side of the existing concrete wall portion. In the residual mold installation step, the new residual mold is supported by the multipurpose post by interposing a support member between the new residual mold and the multipurpose post.
The method for constructing a breakwater according to claim 1, wherein in the placing step, concrete is placed to a position lower than the support member. Including a placing preparation step of horizontally laying concrete pumping pipes on the plurality of multipurpose posts,
The method for constructing a breakwater according to claim 1 or 2, wherein, in the placing step, concrete is placed using the concrete pumping pipe.   4. The method according to claim 1, further comprising a step of arranging a wall bar on an upper side of the existing concrete wall portion and supporting the wall bar with the multipurpose post. 5. How to build a breakwater.   The construction method of a breakwater according to any one of claims 1 to 4, further comprising a PC steel material arranging step of horizontally placing PC steel materials on the plurality of multipurpose posts. A remaining mold installation process in which a new residual mold is erected on an existing residual mold left on one side of the existing concrete wall, and the new residual mold is supported by a column rising from the existing concrete wall. When,
And a placing step of placing concrete on the upper side of the existing concrete wall portion.

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