JP4349508B2 - Construction method of prestressed concrete structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a prestressed concrete structure.
[0002]
[Prior art]
Conventionally, a ground tank made of prestressed concrete has (1) the construction of a bottom plate and a side wall provided with a sheath tube, and then a prestressing force is introduced by inserting a tension material into the sheath tube. And the outer peripheral portion provided with the sheath tube and the side wall provided with the sheath tube, and then inserting a tension material into the sheath tube to introduce the prestress force, and integrating the outer peripheral portion and the inner peripheral portion of the bottom plate, (3) Build the outer periphery of the bottom plate with the sheath tube and the lower part of the side wall, insert the tension material into the sheath tube and introduce a part of the prestress force, then build the inner periphery of the bottom plate and the upper part of the side wall Then, the remaining prestressing power is introduced.
[0003]
[Problems to be solved by the invention]
However, in the method (1), since the side wall and the bottom plate are rigidly joined, a sufficient prestressing force cannot be introduced around the joint. Further, in the methods (2) and (3), the tension material and the reinforcing bar interfere with each other at the outer peripheral portion of the bottom plate, and the construction becomes complicated.
[0004]
The present invention has been made in view of such problems, and the object of the present invention is to provide a prestressed material that can easily arrange a tension material, shorten the construction period, and improve the stress state around the joint between the bottom plate and the side wall. It is to provide a method for constructing a concrete structure and a prestressed concrete structure.
[0005]
[Means for Solving the Problems]
According to a first aspect of the present invention for achieving the above object, in the method of constructing a prestressed concrete structure having a side wall and a bottom slab, a prestressing force is introduced by arranging a tendon along the outside of the bottom slab. It is the construction method of the prestressed concrete structure characterized.
In the first invention, the prestressing force is introduced by arranging the tendon material outside the bottom plate. By arranging the tension material outside the bottom plate, it is possible to avoid interference with the reinforcing bars inside the bottom plate, and the construction becomes easy.
[0006]
2nd invention is the construction method of the prestressed concrete structure which has a side wall and a bottom slab, the process (a) which builds the side wall which has a protrusion part on the outer side and inner side below, and a part of prestress force on the said side wall Pre-stressed, comprising: a step (b) for introducing a bottom plate; a step (c) for constructing a bottom plate inside the side wall; and a step (d) for introducing a prestressing force remaining on the side wall. It is a construction method of a concrete structure.
[0007]
3rd invention is the prestressed concrete structure construction method which has a side wall and a bottom slab, (a) which constructs the lower part of the side wall which has a projection part in the lower outside and inside, and prestresses in the lower part of the side wall A step (b) of introducing a part of the force, a step (c) of constructing a bottom plate inside the lower part of the side wall in parallel with the upper part of the side wall, and a remaining prestress force on the side wall Step (d), and in step (b), a tension material is disposed along the outside of the outside protrusion at the bottom of the side wall at a height position having protrusions on the outside and inside of the side wall. This is a prestressed concrete structure construction method characterized by introducing prestressing force.
[0008]
4th invention is the construction method of the prestressed concrete structure which has a side wall and a bottom slab, (a) which constructs | assembles the side wall which has a protrusion part on the outer side and inner side of the downward | lower, and all the prestress force is applied to the said side wall A step (b) for introducing, and a step (c) for constructing a bottom plate on the inner side of the side wall. In the step (b), at the height position having protrusions on the outer side and the inner side below the side wall. It is a construction method of a prestressed concrete structure, wherein a prestressing force is introduced by arranging a tension material along the outer side of the outer protrusion at the lower side wall.
[0009]
In the third and fourth inventions, a side wall having protrusions on the outside and inside below is constructed to introduce all or part of the prestressing force, a bottom plate is constructed on the inside of the side wall, and if necessary, the side wall Introduce the remaining pre-stress power. Since the prestress is introduced into the side wall without the bottom plate being restrained, the stress state around the joint between the bottom plate and the side wall can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view of a prestressed concrete structure 1, and FIG. 2 is a cross-sectional view of the vicinity of the joint between a bottom slab 5 and a side wall (liquid barrier) 7.
As shown in FIG. 1, the prestressed concrete structure 1 includes a cylindrical side wall (liquid barrier) 7, a disk-shaped bottom slab 5, an outer tank 9, an inner tank 11, and the like. The prestressed concrete structure 1 is, for example, a ground tank.
[0012]
As shown in FIG. 2, first, foundation work is applied to the ground 3 to form a bottom plate 5. Subsequently, the side wall 7 is formed on the bottom plate 5. A plurality of circumferential sheath tubes 13 a are embedded in the side wall 7. A vertical sheath tube 13b is embedded inside the sheath tube 13a. The sheath tube 13 b is disposed over the entire circumference of the side wall 7.
[0013]
Then, the tendon 15a is inserted into the sheath tube 13a, and the tendon 15b is inserted into the sheath tube 13b. A plurality of tension members 17 are arranged as outer cables along the outer periphery of the bottom plate 5. A PC steel material is used for the tension material 15a, the tension material 15b, and the tension material 17.
[0014]
The tension material 17 disposed on the outer peripheral portion of the bottom plate 5, the tension material 15 a disposed on the inside of the side wall 7, and the tension material 15 b are tensioned to introduce a prestress force to the bottom plate 5 and the side wall 7. In some cases, as shown in FIG. 2, a covering member 20 is provided on the outer periphery of the bottom plate 5 to protect the tension member 17. The covering material 20 is, for example, concrete, grout material, filler, or the like. Both ends of the tension material 15a and the tension material 15b are fixed by fixing portions (not shown) provided on the side wall 7, and a grout material or the like is injected into the sheath tube 13a and the sheath tube 13b.
[0015]
3 is a cross-sectional view taken along the line AA in FIG. 1, that is, a plan view of the bottom slab 5, and FIG. 1 is a cross-sectional view when the prestressed concrete structure 1 is cut along B1-B1 in FIG. 4 is a B2-B2 cross-sectional view of FIG. The bottom plate 5 has a fixing portion 19a, a fixing portion 19b, a fixing portion 19c, and a fixing portion 19d on the outer periphery every 90 degrees, and a plurality of circumferential tension members 17 are arranged along the outer periphery.
[0016]
The tension material 17 includes, for example, four tension materials 17a, 17b, 17c, and 17d, and one length is 180 degrees of the outer periphery of the bottom plate 5. At this time, the step composed of the tendon material 17a and the tendon material 17c and the step composed of the tendon material 17b and the tendon material 17d are alternately arranged by shifting by 90 degrees, and the two steps constitute one set. Both ends of the tension material 17a and the tension material 17c are fixed by the fixing portion 19a and the fixing portion 19c, and both ends of the tension material 17b and the tension material 17d are fixed by the fixing portion 19b and the fixing portion 19d.
[0017]
A fixing portion is provided on the outer peripheral portion of the bottom plate 5 every 60 degrees, and one stage is formed by two tension members each having a length of 180 degrees. In some cases, three tensing members having a length of 120 degrees constitute one stage, and the two tiers are shifted by 60 degrees to form one set.
[0018]
The fixing portion 19 c has a sheath tube 18 b along the outer periphery of the bottom plate 5, and the tension material 17 b is passed therethrough. In addition, a sheath tube 18a and a sheath tube 18c are provided so as to cross the inside of the fixing portion 19c, and a tension material 17a and a tension material 17c are respectively passed therethrough. The ends of the tension members 17a and 17c are fixed to the fixing portion 19c using a fixing tool.
[0019]
In parallel with the formation of the bottom plate 5 and the side wall 7, the outer tank 9 and the inner tank 11 are formed. And between the outer tank 9 and the inner tank 11, the heat insulating materials 12, such as a pearlite grain, are filled, and the prestressed concrete structure 1 is completed.
[0020]
As described above, since the tension member 17 on the outer peripheral portion of the bottom plate 5 is of the outer cable type, there is no need to embed a sheath tube in the bottom plate 5 and interference between the tension member 17 and the reinforcing bar can be avoided. Can be shortened and the construction period can be shortened.
[0021]
In the first embodiment, the entire bottom plate 5 and the side wall 7 are collectively formed. However, after the outer peripheral portion of the bottom plate 5 and the lower portion of the side wall 7 are formed and a necessary prestress force is introduced, The center part of the bottom plate 5 and the upper part of the side wall 7 may be formed to introduce the remaining prestress force.
[0022]
In addition, after forming the outer peripheral portion of the bottom plate 5 and the entire side wall 7 and introducing the necessary prestress force, the center portion of the bottom plate 5 is formed to introduce the remaining prestress force, In some cases, after forming the lower portion of the side wall 7 and introducing the necessary prestress force, the upper portion of the side wall 7 is formed and the remaining prestress force is introduced.
[0023]
Here, the necessary prestressing force is all or part of the prestressing force in the completed system. If it is a part of the completed system, the number of the tension members 15a, the tension members 15b, and the tension members 17 to be tensioned is reduced or the respective tension forces are adjusted to appropriately adjust the prestress force to be introduced.
[0024]
Next, a second embodiment will be described. 5 is a plan view of the bottom plate 23, and FIG. 6 is a cross-sectional view in the CC direction of FIG. 5, that is, a cross-sectional view in the vicinity of the joint between the bottom plate 23 and the side wall 24. The bottom plate 23 and the side wall 24 are portions corresponding to the bottom plate 5 and the side wall 7 of the first embodiment, respectively. Below, the part added in 2nd Embodiment is demonstrated.
[0025]
As shown in FIGS. 5 and 6, the side wall 24 includes a circumferential sheath tube 25a and a vertical sheath tube 25b. The bottom plate 23 has four fixing portions 31a, a fixing portion 31b, a fixing portion 31c, and a fixing portion 31d on the outer periphery, and a plurality of convex portions 27 are provided between the fixing portions 31 at predetermined intervals. The convex portion 27 may be formed using a deck plate having a wavy cross section as a mold.
[0026]
And, the step composed of the tension material 29a and the tension material 29c, and the step composed of the tension material 29b and the tension material 29d are alternately arranged 90 degrees along the outside of the convex portion 27 of the bottom plate 23, Tension and fix to fixing unit 31a, fixing unit 31b, fixing unit 31c, and fixing unit 31d using a fixing tool. For example, both ends of the tendon material 29a are fixed to the fixing unit 31a and the fixing unit 31c. In some cases, a covering material (not shown) such as protective concrete is provided outside the convex portion 27 to protect the tension material 29.
[0027]
Next, a third embodiment will be described. 7 is a plan view of the bottom plate 43, and FIG. 8 is a cross-sectional view in the DD direction of FIG. 7, that is, a cross-sectional view in the vicinity of the joint between the bottom plate 43 and the side wall 44. The bottom plate 43 and the side wall 44 correspond to the bottom plate 23 and the side wall 24 of the second embodiment, respectively.
[0028]
Similar to the second embodiment, the side wall 44 includes a circumferential sheath tube 45a and a vertical sheath tube 45b. The bottom plate 43 has four fixing portions 51a, a fixing portion 51b, a fixing portion 51c, and a fixing portion 51d on the outer periphery, and a plurality of convex portions 47 are provided between the fixing portions 51 at predetermined intervals.
[0029]
Further, the convex portion 47 has a plurality of tubes 53 in the circumferential direction. The stage composed of the tension material 49a and the tension material 49c and the stage composed of the tension material 49b and the tension material 49d are alternately arranged by shifting by 90 degrees through the inside of the pipe 53, and are tensioned, and using a fixing tool. The fixing unit 51a, the fixing unit 51b, the fixing unit 51c, and the fixing unit 51d are fixed.
[0030]
As described above, also in the second and third embodiments, the lower tension member 29 or the tension member 49 is the outer cable type, so that it is not necessary to embed a sheath tube in the bottom plate 23 or the bottom plate 43. Since the interference between the material 29 or the tension material 49 and the reinforcing bar can be avoided, the construction becomes easy.
Similar to the first embodiment, a tension member can be disposed by providing a fixing portion at an outer peripheral portion of the bottom plate 23 or the bottom plate 43, for example, every 60 degrees.
[0031]
Next, a fourth embodiment will be described. FIG. 9 is a schematic view of the prestressed concrete structure 101, and FIG. 10 is a cross-sectional view of the side wall (liquid barrier) 103a. As shown in FIG. 9, the prestressed concrete structure 101 includes a cylindrical side wall (breakwater) 103 a and a side wall (breakwater) 103 b, a disk-shaped bottom slab 110, an outer tank 111, an inner tank 113, and the like. The The prestressed concrete structure 101 is, for example, a ground tank.
[0032]
As shown in FIG. 10, first, foundation work such as placement of the support pile 106 is performed on the ground 102 to form a reinforced concrete side wall 103a. The side wall 103a has a protruding portion 104a on the outer side of the lower portion and a protruding portion 104b on the inner side. A plurality of circumferential sheath tubes 105a are embedded in the side wall 103a. A vertical sheath tube 105b is embedded inside the sheath tube 105a. The sheath tube 105b is disposed over the entire circumference of the side wall 103a.
[0033]
Then, the tendon material 107a is inserted into the sheath tube 105a. In some cases, a plurality of tendons 109 are arranged as outer cables along the outer periphery of the protruding portion 104a of the side wall 103a. PC steel material is used for the tension material 107a, the tension material 107b, and the tension material 109.
[0034]
Here, the protruding portion 104a at the lower portion of the side wall 103a has the same structure as the outer peripheral portion of the bottom plate 5 of the first embodiment, and, for example, four fixing portions (not shown) are provided every 90 degrees. . The tendon material 109 corresponds to the tendon material 17 of the first embodiment. For example, the tension material 109 is composed of four pieces of 180 degrees on the outer periphery of the protruding portion 104a, and is disposed along the outer periphery of the protruding portion 104a.
[0035]
The tension material 107a and the tension material 109 are tensioned, and a part of the necessary prestress force is introduced into the side wall 103a. At this time, the number of the tension members 107a and the tension members 109 to be tensioned is reduced or the respective tension forces are adjusted to appropriately adjust the prestress force to be introduced. If necessary, the tendon 107b is inserted into the sheath tube 105b and is tensioned.
[0036]
Next, the side wall 103b is formed on the upper side of the side wall 103a, and the bottom plate 110 is formed inside the side wall 103a in parallel. The bottom plate 110 is supported by the support pile 106, for example. Further, the bottom plate 110 may be supported by the ground 102 without providing the support pile 106.
[0037]
FIG. 11 is an enlarged view of a lower portion of the side wall 103 of FIG. 9 and 11, the bottom surface of the bottom plate 110 is in contact with the upper end of the protruding portion 104b. However, as shown in FIG. 12, the upper surface of the bottom plate 110 and the upper end of the protruding portion 104b are continuously located at the same height. May be formed. In this case, the bottom slab 110 is supported by the ground 102, but a support pile 106 may be provided below the bottom slab 110 as in FIG.
[0038]
As shown in FIG. 11, a plurality of circumferential sheath tubes 105c are embedded in the side wall 103b. A vertical sheath tube 105b is embedded inside the sheath tube 105c. The tendon 107c is inserted into the sheath tube 105c, and the tendon 107b is inserted into the sheath tube 105b.
[0039]
The tension material 107b is tensioned to introduce a prestressing force in the vertical direction. Then, at the same time as the tension material 107c is tensioned, the tension material 107a and the tension material 109 on the side wall 103a are also tensioned, and the remaining prestress force is introduced.
[0040]
Both ends of the tendon material 107a, the tendon material 107b, and the tendon material 107c are fixed by fixing portions (not shown) provided on the side walls 103a and 103b, and the grout material is provided inside the sheath tube 105a, the sheath tube 105b, and the sheath tube 105c. Etc. are injected.
[0041]
Both ends of the tension material 109 are fixed by fixing portions (not shown) provided on the outer periphery of the protruding portion 104a of the side wall 103a. In some cases, as shown in FIG. 11, a covering material 117 such as protective concrete is provided on the outer periphery of the protruding portion 104 a to protect the tension material 109.
[0042]
In parallel with the formation of the side wall 103a, the bottom plate 110, and the side wall 103b, the outer tank 111 and the inner tank 113 are formed. And between the outer tank 111 and the inner tank 113, the heat insulating material 115, such as a pearlite grain, is filled, and the prestressed concrete structure 101 is completed.
[0043]
Thus, the construction period can be shortened by constructing the side wall 103b and the bottom plate 110 on which the sheath tube is not disposed in parallel. In addition, since prestress is introduced into the side wall 103a without the restraint of the bottom plate 110, the stress state around the joint between the bottom plate 110 and the side wall 103a can be improved.
[0044]
In the fourth embodiment, the side wall 103a and the side wall 103b are sequentially formed, but the side wall 103a and the side wall 103b may be integrally formed. In that case, after all or part of the prestressing force is introduced into the side wall 103, the bottom plate 110 is formed, and the remaining prestressing force is introduced as necessary. The formation of the side wall 103b and the introduction of the prestressing force can be further subdivided.
[0045]
Further, the protruding portion 104a of the side wall 103a has the same structure as the outer peripheral portion of the bottom plate 23 of the second embodiment or the outer peripheral portion of the bottom plate 43 of the third embodiment, and the lower tension material is also arranged in the same manner. be able to. A tension tube may be disposed in the circumferential direction by providing a sheath tube inside the protruding portion 104a of the side wall 103a.
[0046]
【The invention's effect】
As described above in detail, according to the first invention, the arrangement of the tension material is easy, the construction period can be shortened, and in the second invention, the prestressed stress can be improved around the joint between the bottom plate and the side wall. A method for constructing a concrete structure and a prestressed concrete structure can be provided.
[Brief description of the drawings]
1 is a schematic view of a prestressed concrete structure 1. FIG. 2 is a cross-sectional view of the vicinity of a joint between a bottom slab 5 and a side wall (a breakwater) 7. FIG. 3 is a cross-sectional view taken along a line AA in FIG. FIG. 5 is a plan view of the bottom plate 23. FIG. 6 is a cross-sectional view in the direction CC of FIG. 5. FIG. 7 is a plan view of the bottom plate 43. FIG. FIG. 9 is a schematic view of the prestressed concrete structure 101. FIG. 10 is a sectional view of the side wall 103a. FIG. 11 is an enlarged view of the lower part of the side wall 103 in FIG. Schematic diagram of the embodiment [Explanation of symbols]
1 ... Prestressed concrete structure 5 ... Bottom plate 7 ... Side walls 13a, 13b ... Sheath tubes 15a, 15b ... Tension members 17 ... Tension members 19a, 19b, 19c, 19d ... Fixing portion 20 ... Covering material 23 ... Bottom plate 27 ... Convex portions 29a, 29b, 29c, 29d ... Tension material 43 ... Bottom plate 47 ... ... Convex portions 49a, 49b, 49c, 49d ... …… Tensile material 101 …… Prestressed concrete structures 103a, 103b ...... Side walls 104a, 104b ...... Projections 105a, 105b, 105c ...... Sheath tubes 107a, 107b, 107c ...... Tensile material 109 ... tension material 110 ... ... bottom plate 117 ... ... covering material

Claims (12)

  In the construction method of the prestressed concrete structure which has a side wall and a bottom plate, the prestressed concrete structure construction method characterized by arrange | positioning a tension material along the outer side of the said bottom plate, and introduce | transducing prestress force.   2. The method for constructing a prestressed concrete structure according to claim 1, wherein the bottom plate has convex portions on an outer periphery at predetermined intervals, and the tension material is disposed along the outside of the convex portions.   3. The method for constructing a prestressed concrete structure according to claim 1, wherein after the tension material is tensioned and a prestressing force is introduced to the bottom plate, a covering material is provided outside the tension material.   The method for constructing a prestressed concrete structure according to claim 1, wherein the bottom slab has protrusions on the outer periphery at predetermined intervals, and the tension material is disposed through the protrusions.   In the construction method of a prestressed concrete structure having a side wall and a bottom slab, a step (a) of constructing a side wall having protrusions on the lower outside and inside, and a step of introducing a part of the prestressing force into the side wall (b And a step (c) of building a bottom slab inside the side wall, and a step (d) of introducing the remaining prestressing force to the side wall, and a method for constructing a prestressed concrete structure, . In the step (b), a prestressing force is introduced by arranging a tension material along the outer side of the outer protruding portion of the lower side wall at a height position having protruding portions on the outer side and the inner side below the side wall. The method for constructing a prestressed concrete structure according to claim 5. In the method for constructing a prestressed concrete structure having a side wall and a bottom plate, a step (a) of constructing a lower part of the side wall having a protruding part on the outside and inside on the lower side, and introducing a part of the prestress force into the lower part of the side wall Parallel to the upper part of the side wall, the step (c) of building a bottom plate inside the lower part of the side wall, the step (d) of introducing the remaining prestress force to the side wall, Comprising
In the step (b), a prestressing force is introduced by arranging a tension material along the outer side of the outer protruding portion of the lower side wall at a height position having protruding portions on the outer side and the inner side below the side wall. A method for constructing a prestressed concrete structure. In the construction method of a prestressed concrete structure having a side wall and a bottom slab, a step (a) of building a side wall having protrusions on the outside and inside of the lower side, and a step (b) of introducing all of the prestressing force to the side wall And (c) constructing a bottom plate inside the side wall,
In the step (b), a prestressing force is introduced by arranging a tension material along the outer side of the outer protruding portion of the lower side wall at a height position having protruding portions on the outer side and the inner side below the side wall. A method for constructing a prestressed concrete structure.   The projecting portion on the outer side of the side wall has convex portions at a predetermined interval on an outer periphery, and the tension material is disposed along the outer side of the convex portion. The method for constructing a prestressed concrete structure according to claim 8.   The tension material arrange | positioned along the outer periphery of the said outer side protrusion part of the said side wall is tensioned, A pre-stress force is introduced, Then, a coating | covering material is provided in the outer side of the said tension material. The construction method of the prestressed concrete structure of Claim 7, Claim 8, or Claim 9.   The protruding portion on the outer side of the side wall has convex portions on the outer periphery at a predetermined interval, and the tension material is disposed through the convex portion. Item 9. A method for constructing a prestressed concrete structure according to item 8. 6. The prestressed concrete according to claim 5, wherein in the step (b), a prestressed force is introduced by disposing a tension material inside the lower part of the side wall at a height position having protrusions on the outside and inside of the side wall. How to build a structure.

Images