JP2005306445A - Lateral wall members for pre-cast pc tank and joint structure between lateral wall members and bottom plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the construction period for completing lateral walls by connecting a pre-cast PC tank lateral wall member with adjacent lateral wall members while joining with a bottom plate in such a way that the lateral wall members can be rotationally displaced relative to the bottom plate. <P>SOLUTION: In the pre-cast concrete lateral wall members 1 that are installed circumferentially continuously on the reinforced concrete bottom plate 3, and constituting the pre-cast PC tank lateral walls 2 by the introduction of prestress circumferentially, a foot portion 1B having an insert hole 1a through which a fixing member 4 fixed in the bottom plate 3 and projecting from the top end of the bottom plate 3 can be inserted is integrally formed at either the inner circumferential side or outer circumferential side of the lateral walls 2 at the lower end of a body portion 1A having through holes 1b for inserting tension members 12 for introducing prestress circumferentially to the lateral walls 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a side wall member made of precast concrete that constitutes a side wall of a precast PC tank, and a joint structure between the side wall member and the bottom plate in which the lower end portion of the side wall member is joined to the bottom plate so as to be capable of rotational displacement relative to the bottom plate Is.

  In the precast PC tank, a precast concrete side wall member 1 constituting a cylindrical side wall 2 as shown in FIG. After the installation of is completed, prestress is introduced in the circumferential direction of the side wall 2 to complete the side wall 2, and a roof member made of precast concrete is also constructed on the top of the side wall 2.

The joining method of the lower end portion of the side wall member 1 and the bottom plate 3 includes a free support that allows a horizontal relative displacement between them and a rotational displacement around a horizontal axis, a hinge support that allows only a rotational displacement, and a horizontal displacement. However, as shown in FIG. 9, when the side wall member 1 is rotated relative to the bottom plate 3 during an earthquake, excessive stress is generated at the joint between the two. The hinge support which can avoid this is employ | adopted (refer patent document 1 and patent document 2).
Japanese Patent Publication No. 6-55366 (Fig. 4) Japanese Unexamined Patent Publication No. 2004-68480 (FIGS. 1, 8, and 9)

  When the lower end portion of the side wall member 1 is joined to the bottom plate 3 in a hinged state, the side wall member 1 is installed on the bottom plate 3 as shown in FIGS. After introducing prestress by placing a tension member such as the side wall, the side wall 2 is anchored in the bottom slab 3 on the outer peripheral side of the side wall 2, and the upper end protrudes from the top edge of the bottom slab 3 using the anchor bolt 21 and the cast-in-place concrete 22. Joining the lower end part of the member 1 and the bottom plate 3 is performed.

  A leveling mortar 6 is laid at the top of the installation position of the side wall member 1 around the bottom slab 3, and between the leveling mortar 6 and the side wall member 1, the side wall member 1 is leveled during an earthquake. A bearing member 7 such as rubber is interposed to allow rotational displacement while suppressing displacement. The joint material 8 is installed around the anchor bolt 21 so as to avoid the restraint of the anchor bolt 21 due to the cast-in-place concrete 22 wrapping around and allow the anchor bolt 21 to be bent and deformed.

  For example, the side wall member 1 and the bottom plate 3 are connected to anchor bars fixed on the side wall member 1 and reinforcing bars arranged in the in-situ concrete 22 and the in-situ concrete 22 is placed so as to surround these reinforcing bars. Therefore, it takes a plurality of work steps of rebar assembly, formwork installation, concrete placement, and curing before the hinge structure is completed. In addition, the reinforcing bar arrangement and the concrete placement must be performed over the entire circumference of the side wall member 1, so that the construction period from the installation of the side wall member to the completion of the side wall must be prolonged.

  The cast-in-place concrete 22 portion needs to behave integrally with the side-wall member 1 in order to support the side-wall member 1 so as to be rotatable about the horizontal axis with respect to the bottom slab 3 during an earthquake. As a result, the integrity of the wall member 1 and the side wall member 1 depends on the field work.

  In view of the above background, the present invention proposes a joint structure between the bottom plate and the side wall member that ensures the integrity of the cast-in-place concrete portion and the side wall member and can shorten the construction period until the side wall is completed.

  In the present invention, at the lower end of the side wall member made of precast concrete, there is an insertion hole through which anchor bolts, anchor bars and other fixing materials protruding from the top end of the bottom plate can be inserted in the fixing material protruding direction such as the vertical direction. By integrally forming the legs corresponding to the conventional cast-in-place concrete part, the conventional cast-in-place concrete part and the side wall member are completely integrated, and on-site reinforcement work and concrete placement work are performed. Eliminates the need for shortening the work period until completion of the sidewall.

  The side wall member is integrated with the main body part on the inner peripheral side or outer peripheral side of the side wall of the main body part having a through-hole through which a tensile material for introducing prestress in the circumferential direction of the side wall is inserted. The leg part is formed with two parts, and an insertion hole is formed in the leg part. The fixing part is fixed in the bottom plate and the upper end protrudes from the top end of the bottom plate to allow the fixing material to pass therethrough.

  Legs corresponding to conventional cast-in-place concrete parts are integrated with the main body of the side wall member as part of the precast concrete side wall member. There is no room for occurrence, and there is no problem that the integrity of the main body and the leg is impaired.

  In addition, since the legs are integrated with the main body when manufacturing the side wall member, the side wall member is installed on the bottom plate and connected to the adjacent side wall member, and the side wall is completed simply by introducing prestress in the circumferential direction. Therefore, the conventional on-site bar arrangement work, formwork assembly, concrete placement, and curing are unnecessary, and the work period is shortened accordingly.

  Further, since the conventional side wall member has only a portion corresponding to the main body of the present invention, conventionally, the side wall member is installed and held while being suspended and supported until the connection is completed. In the present invention, the side wall member is placed on the bottom plate at the bottom surface of the main body and the bottom surface of the leg portion, so that the stability in the state where the side wall member is installed on the bottom plate is increased, and the suspended side wall member Since the suspension support can be released and self-supported after abuts against the adjacent side wall member, the efficiency of hanging the side wall member is increased, the construction efficiency up to the completion of the side wall is increased, and the construction period is shortened from this aspect as well. Is planned.

  The main body portion of the side wall member excluding the leg portion is formed in a flat plate shape as shown in FIGS. 6 (a) to 6 (c), and is formed in a curved or bent shape toward the outer peripheral side of the side wall. In installing the side wall member on the bottom plate, it does not matter whether the leg portion is formed on the inner peripheral side or the outer peripheral side of the main body portion.

  However, since the side wall member forms a cylindrical side wall by being connected in the circumferential direction even if the shape of the main body is flat as shown in FIG. As shown in the figure, the leg portions of the adjacent side wall members are end faces in the circumferential direction so that the length of the main body portion in the circumferential direction decreases from the outer peripheral side to the inner peripheral side. When the legs are formed on the outer peripheral side of the main body, when the legs are formed so as to be brought into contact with each other, the legs expand into a trapezoidal shape or a fan shape from the inner peripheral side to the outer peripheral side of the main body. It becomes a protruding shape.

  As a result, when the adjacent side wall members are connected, the end portions in the circumferential direction of the leg portions easily collide with each other, which may be an obstacle during the connecting operation. Even when the body part of the side wall member is convexly curved or bent to the outer peripheral side, if the leg part is formed on the outer peripheral side of the main body part, the leg part extends from the inner peripheral side to the outer peripheral side of the main body part. Therefore, in order to alleviate the collision problem, it is desirable to form the leg portion on the inner peripheral side of the side wall as described in claim 2.

  When the legs are formed on the inner peripheral side of the main body of the side wall member, when the legs are formed so that the legs of the adjacent side wall members abut each other at the end surfaces in the circumferential direction, On the contrary, the circumferential length of the leg portion is reduced from the outer peripheral side to the inner peripheral side, so that the circumferential end portion of the leg portion is suspended when the side wall member is suspended and when the adjacent side wall member is connected. Therefore, the workability of the suspension and connection is improved, and the work period until the side wall is completed can be further shortened by improving the work efficiency.

  In the state where the bottom plate is constructed, there is a possibility that unevenness has occurred at the top edge of the installation position of the side wall member in the surrounding area, so a leveling mortar should be used to align or adjust the height of all side wall members. May need to be laid.

  On the other hand, if one or a plurality of nuts (inserts) into which the height adjusting bolts are screwed from below are embedded in the bottom surface side of the side wall member including the leg portions as described in claim 3. , It is possible to adjust the level at the time of installing the side wall member by screwing the height adjusting bolt into the nut before installing the side wall member, which corresponds to the case where the top end of the bottom plate is uneven. In addition to eliminating the need for leveling mortar, it can also be used in cases where unevenness occurs in the leveling mortar or when fine adjustment is required when connecting adjacent side wall members. can do.

  As described in claim 4, the side wall member made of precast concrete is placed on the bottom plate while the fixing material protruding from the top end of the bottom plate is inserted into the insertion hole of the leg portion, and is not inserted into the insertion hole of the leg portion. By filling with a filler such as shrink mortar, the bottom slab is joined to the bottom slab so that it can be rotationally displaced while restraining horizontal displacement during an earthquake.

  In this case, since the leg portion is integrated with the side wall member, the side wall member is suspended while the fixing material is inserted into the insertion hole of the leg portion, and the fixing material is inserted into the leg portion only by being placed on the bottom plate. Since the side wall member can be joined to the bottom plate simply by filling the insertion hole with the filler, the joining operation between the side wall member and the bottom plate is simplified, and the suspended side wall There is an advantage that the self-supporting property of the member is ensured, and the efficiency of suspending the side wall member is increased, and the connecting operation of the side wall member and the joining operation to the bottom plate are made efficient.

  When the side wall member according to claim 2 is used, the end portions in the circumferential direction of the leg portions are less likely to collide with each other. When the side wall member is used, it is possible to cope with the unevenness of the top of the bottom slab, and there is an advantage that it is unnecessary to install a leveling mortar.

  A leg part with an insertion hole through which the fixing material protruding from the top edge of the bottom plate can be inserted at the lower end of the precast concrete side wall member, and the conventional cast-in-place concrete part and the side wall member are completely integrated. Therefore, the on-site reinforcement work, concrete placement work, and formwork assembly are not required, and the concrete curing period is eliminated, and the construction period until the side wall is completed can be greatly shortened.

  Moreover, the problem that the integrity of a leg part and a side wall member resulting from the construction defect and construction error which may arise when integrating a leg part with a side wall member on-site is eliminated.

  According to claim 2, the leg portion is formed on the inner peripheral side of the side wall, and the length of the leg portion in the circumferential direction is reduced from the outer peripheral side to the inner peripheral side of the side wall, so that it is adjacent to when the side wall member is suspended. Since the end portions in the circumferential direction of the leg portions are less likely to collide with each other when the side wall members are connected, the workability of the suspension and connection is improved, and the construction period until the side wall is completed can be further shortened.

  According to the third aspect of the present invention, the height adjusting bolt can be screwed into the nut before the side wall member is installed by embedding a nut into which the height adjusting bolt is screwed on the bottom surface side of the side wall member including the leg portion. Therefore, it is possible to cope with the unevenness of the top of the bottom plate, and the installation of leveling mortar can be omitted. Moreover, it can respond to unevenness of leveling mortar, and fine adjustment at the time of connecting the side wall members can also be performed.

  According to the fourth aspect of the present invention, since the leg portion is integrated with the side wall member, the side wall member is suspended while the fixing material is inserted into the insertion hole of the leg portion, and is simply placed on the bottom plate. In addition to being able to be inserted, the side wall member can be joined to the bottom plate simply by filling the insertion hole with the filler, so the joining operation between the side wall member and the bottom plate is simplified, and the side wall member connecting operation and the bottom plate are simplified. The efficiency of the joining work to can be improved.

  As shown in FIGS. 4 (a) and 4 (b), the invention described in claim 1 is continuously installed in the circumferential direction on a reinforced concrete bottom slab 3 and prestress is introduced in the circumferential direction. It is the side wall member 1 made from the precast concrete which comprises the cylindrical side wall 2 of a precast PC tank.

  The precast PC tank is continuously installed on the bottom plate 3 while the side wall member 1 is adjacent to the circumferential direction of the bottom plate 3, and after the installation of all the side wall members 1 is completed, the PC steel material, fiber reinforced material, etc. It is constructed by inserting a tension member 12 and tensioning it, introducing prestress in the circumferential direction of the side wall 2 to complete the side wall 2, and laying a roof member made of precast concrete (not shown) on the top of the side wall 2. The The precast PC tank is used as a water storage tank, an agricultural water tank, a livestock manure tank or other various storage tanks.

  As shown in FIGS. 5A to 5C, the side wall member 1 has a plurality of through holes 1b through which a plurality of tensile members 12 for introducing prestress in the circumferential direction of the side wall 2 are inserted. The main body 1A and the lower end of the main body 1A are integrally formed with the main body 1A on the inner peripheral side or the outer peripheral side of the side wall 2, and are fixed in the bottom plate 3. The upper end is the top edge of the bottom plate 3. An anchor bolt or an anchor bar projecting from the plate, or a leg portion 1B joined to the fixing material 4 such as a plate, and an insertion hole 1a through which the fixing material 4 can be inserted is formed in the leg portion 1B. A sheath may be disposed in the through hole 1b of the main body 1A.

  5- (b) and (c) are pilasters arranged at a plurality of circumferential positions (four in the drawing) in the side wall 2 shown in FIG. The side wall member 1 as a member is shown, and FIG. 5- (a) shows the side wall member 1 of the other standard part. 6 (a) shows the plane of the side wall member 1 shown in FIG. 5- (a), and FIGS. 6 (b) and (c) show the plane of the side wall member 1 shown in FIGS. 5- (b) and (c), respectively. .

  For example, as shown in FIG. 7, the tension member 12 is half-turned at the same level in the circumferential direction of the side wall 2 and is fixed to the side wall member 1 as a pilaster member disposed at that position. Since the fixing positions are made to differ by 1/4 turn in FIG. 7, the side wall member 1 of the same type (type A or type B) is located symmetrically with respect to the center of the side wall 2 as shown in FIGS. (Pilaster member) is arranged, and as shown in FIGS. 5B and 5C, the fixing position of the tension member 12 is different between Type A and Type B. Each of FIGS. 5 and 6 shows a type A side wall member 1 and FIG. 5C shows a type B side wall member 1. FIG. 8A shows the fixing state of the end portion of the tension member 12 in the side wall member 1 of type A, and FIG. 8-B shows the fixing state of the end portion of the tension member 12 in the side wall member 1 of type B.

  The leg 1B is integrally formed on the inner peripheral side of the side wall 2 or the outer peripheral side as shown in FIG. 3 at the lower end of the main body 1A as shown in FIGS. There is an insertion hole 1a through which the fixing material 4 protruding from the end can be inserted. As shown in the figure, the fixing material 4 is inserted into the insertion hole 1a in the vertical direction or the like in the protruding direction of the fixing material 4.

  As shown in the figure, when the leg 1B is formed on the inner peripheral side of the main body 1A (Claim 2), the leg 1B is moved from the outer peripheral side to the inner peripheral side as shown in FIGS. 6 (a) to (c). Since the flat area of the leg portion 1B is smaller than the case where it is formed on the outer peripheral side, the leg portion is suspended when the side wall member 1 is suspended and when the adjacent side wall members 1 and 1 are connected. 1B and 1B are less likely to collide with each other, making it easier to work.

  The leg 1B is formed so as to continuously extend from the lower end of the main body 1A to the inner peripheral side or the outer peripheral side of the main body 1A, and the bottom surfaces of the main body 1A and the leg 1B are side walls 1 on the bottom plate 3 Is formed on a flat surface or a concave surface in order to obtain stability when mounted.

  As shown in FIGS. 6 (a) to 6 (c), the insertion holes 1a are formed by the number of fixing members 4 protruding to join one side wall member 1 to the bottom plate 3. In the drawing, the insertion hole 1a is formed so as to penetrate from the bottom surface to the top surface of the leg portion 1B. However, the insertion hole 1a is not necessarily penetrated, and the fixing material 4 is inserted into the insertion hole 1a, and a gap around the fixing material 4 is formed. It suffices if it is formed so that it can be filled with a filler 5 such as a non-shrink mortar or an adhesive.

  Further, since the side wall member 1 tends to be rotationally displaced with respect to the bottom plate 3 at the time of an earthquake, a clearance that does not hinder the rotational displacement is secured between the inner peripheral surface of the insertion hole 1a and the surface of the fixing material 4. The In the drawing, the insertion hole 1a is formed in a cylindrical shape with the same diameter from the bottom surface to the top surface of the leg 1B, but the diameter increases from the bottom to the top so as to easily follow the rotational displacement, for example, a conical shape. It may be formed in a shape similar to that.

  As shown in FIG. 1, the side wall member 1 is placed on the bottom plate 3 while the fixing material 4 protruding from the top end of the side wall member 1 is inserted into the insertion hole 1a of the leg 1B. The filling material 5 is filled in the insertion hole 1a.

  When the side wall member 1 is placed directly on the top edge of the bottom slab 3, a leveling mortar 6 is laid on the top edge of the bottom slab 3 as shown in FIGS. A bearing member 7 such as rubber for allowing rotational displacement while interposing horizontal displacement of the side wall member 1 is interposed. The support member 7 is disposed at the position of the bottom surface of the main body 1A excluding at least the leg 1B. Around the fixing material 4, the filler 5 filled in the insertion hole 1 a flows out between the bottom surface of the side wall member 1 and the bottom plate 3 so that the fixing material 4 is not restrained by the filler 5. The joint material 8 is disposed, and the bending deformation capability of the fixing material 4 is ensured.

  The top end level of the bottom slab 3 at the position on which the side wall member 1 is placed is set lower than the top end level of the inner peripheral portion in order to restrain movement of the side wall member 1 toward the inner peripheral side of the side wall 2. A packing 9 is sandwiched between the inner peripheral surface of the lower end portion of 1 and the portion where the level changes in order to protect the lower end portion of the side wall member 1.

  FIG. 3 shows the case where the leg 1B is formed on the outer peripheral side of the side wall 2 at the lower end of the main body 1A. In this case as well, the support material 7 is placed around the fixing material 4 at least on the bottom surface of the main body 1A. The joint material 8 is disposed, and the packing 9 is sandwiched between the inner peripheral surface of the lower end portion of the side wall member 1 and the portion where the level changes.

  FIG. 2 (a) and FIG. 6 show that when the side wall member 1 is manufactured, a nut 10 into which a height adjusting bolt 11 is screwed from below is embedded on the bottom surface side of the side wall member 1 including the leg portion 1B. An example in which the height adjustment bolt 11 is screwed into the nut 10 before the installation of 1 and the level at the time of installation of the side wall member 1 is adjusted by adjusting the screwing length is shown. 2- (b) shows the details of FIG. 2- (a) at the lower end of the side wall member 1 shown in FIGS. 5- (b), (c). The head of the height adjustment bolt 11 is placed on the plate 13 to ensure stability.

  In the case of FIG. 2, since the level of the side wall member 1 is adjusted by the height adjusting bolt 11, the leveling mortar 6 is not laid in the drawing. Further, since the height adjusting bolt 11 protrudes from the bottom surface of the side wall member 1, the distance between the bottom surface of the side wall member 1 and the top end surface of the bottom plate 3 becomes larger than in the case of FIG. Therefore, the support material 7 and the joint material 8 are not arranged, and the filler 5 filled in the insertion hole 1a is wrapped around the bottom surface of the side wall member 1.

It is the longitudinal cross-sectional view which showed the junction part of the side wall member and leg plate which formed the leg part in the inner peripheral side. (a) is a longitudinal sectional view showing a state in which a height adjusting bolt is screwed into a nut embedded on the bottom surface side of the side wall member to adjust the height of the side wall member, and (b) is a view of (a). It is the longitudinal cross-sectional view of the nut part which showed the detail. It is the longitudinal cross-sectional view which showed the junction part of the side wall member and leg plate which formed the leg part in the outer peripheral side. (a) is the top view which showed the side wall comprised by connecting a side wall member, (b) is the partial cross section side view of (a). (a)-(c) is the side view which showed the side wall member from which a type differs. (a)-(c) is the top view which showed the arrangement | positioning state of each side wall member shown to FIG. 5- (a)-(c). It is the top view which showed the arrangement | positioning state of the tension material in the whole side wall. FIG. 6A is a plan view showing a fixing state of the tensile material in the side wall member shown in FIG. 6B, and FIG. 6B is a plan view showing the fixing state of the tensile material in the side wall member shown in FIG. FIG. It is the longitudinal cross-sectional view which showed the mode of joining of the conventional side wall member and a bottom plate. (a)-(c) is the longitudinal cross-sectional view which showed the procedure of joining of the side wall member and bottom plate which are shown in FIG. It is the perspective view which showed the side wall comprised by connecting a some side wall member.

Explanation of symbols

1 …… Side wall member, 1A …… Main body, 1B …… Leg, 1a …… Insertion hole,
2 ... side wall, 3 ... bottom plate, 4 ... fixing material, 5 ... filler, 6 ... leveling mortar,
7 ... Bearing material, 8 ... Joint material, 9 ... Packing,
10 …… Nut, 11 …… Height adjustment bolt, 12 …… Tension material, 13 …… Plate

Claims (4)

  It is a side wall member made of precast concrete that is continuously installed in the circumferential direction on a reinforced concrete bottom plate and prestressed in the circumferential direction to form the side wall of the precast PC tank. From the two parts of the body part having a through-hole through which a tensile material for introduction is inserted and the leg part integrally formed with the body part on the inner peripheral side or outer peripheral side of the side wall of the lower end part of the main body part A side wall member for a precast PC tank in which an insertion hole through which a fixing material fixed in the bottom plate and having an upper end protruding from the top end of the bottom plate can be inserted is formed in the leg portion.   The side wall member for a precast PC tank according to claim 1, wherein the leg portion is formed on the inner peripheral side of the side wall, and the circumferential length of the leg portion is reduced from the outer peripheral side to the inner peripheral side of the side wall.   The side wall member for a precast PC tank according to claim 1 or 2, wherein one or a plurality of nuts into which height adjusting bolts are screwed from below are embedded on the bottom surface side of the side wall member including the legs. . A joint structure in which the side wall member according to any one of claims 1 to 3 is joined to the bottom slab so as to be rotationally displaceable with respect to the bottom slab while restraining horizontal displacement during an earthquake, and protrudes from the top end of the bottom slab. For a precast PC tank in which the side wall member is placed on the bottom plate while the fixing material being inserted is inserted into the insertion hole of the leg, and the side wall member is joined to the bottom plate by filling the insertion hole of the leg. The junction structure of the side wall member and the bottom plate.

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