JP2004360399A - Concrete member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concrete member capable of improving the overall rigidity and flexibility of a structure, reducing works at a site at a time when the concrete member is connected. <P>SOLUTION: In the concrete member 1a to 1e used by a coupling in the predetermined direction, pairs of joint sections 7a and 7b are installed to end faces on both sides of the concrete members 1a to 1e, the adjacent concrete members 1a to 1e are connected by the joint sections 7a and 7b while tension members 5 coupling pairs of the joint sections 7a and 7b are mounted in the concrete members 1a to 1e. In the concrete members, a prestress is introduced to the concrete members 1a to 1e by tensioning the tension members 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a concrete member used to construct a building in connection with each other.
[0002]
[Prior art]
2. Description of the Related Art A pre-manufactured concrete member, a so-called precast concrete member, is used in many applications, such as a building or structure on the ground, an underground tunnel, and an underground conduit. This concrete member is usually manufactured as a segment in which a structure to be constituted is divided into parts, transported to a site, and assembled to be integrated. For example, when constructing a shield tunnel, an arcuate plate-shaped concrete segment is connected in the circumferential direction to form an annular assembly having a unit length, and these are sequentially added in the axial direction to form a cover as a building. Build a body. As a method of connecting the assemblies, it has been common practice to embed a fitting in a bolt box near the opposing joint end and connect the fittings to each other with bolts and nuts.
[0003]
However, in such a method of connecting the joint fittings with bolts and nuts, since the region to be connected is only a partial region near the end face, the rigidity of the connection portion tends to be insufficient. In addition, the work of tightening bolts is poor in work performed in a narrow space inside the drilling hole, and the joint fittings and bolts are exposed inside the lining body, so that secondary covering work cannot be omitted. There was. Therefore, for example, in Patent Document 1, the above-mentioned problem is solved by embedding a pair of connecting fittings in an end face in the axial direction of a concrete segment and fitting them by fitting each other.
[0004]
In addition, since concrete has a tensile strength of about 1/10 of the compressive strength, a steel material or the like having both ends fixed to the concrete is provided inside, and this is tensioned to apply a compressive stress to the concrete by the reaction force. Prestress is being introduced. For example, in Patent Literature 2, when a shield tunnel is constructed, a common tension member (PC steel material) is inserted into a duct (sheath) formed in an axial direction and tensioned in a state where annular bodies are connected to each other. Thus, it is described that a plurality of annular bodies are prestressed.
[0005]
[Patent Document 1]
JP 2003-27893 A [Patent Document 2]
JP-A-11-81891
[Problems to be solved by the invention]
For example, when the ground in the construction section of the shield tunnel is soft and subsidence is expected in the future, the constructed primary lining body is required to have some flexibility. In the method of forming a bolt box as described above, it is conceivable to fasten by combining an elastic washer and a bolt, but when the bolt box bears a tensile force and a large tensile force acts, Its structure becomes complicated.
[0007]
Further, in the technique described in Patent Document 1 described above, improvement in workability and prevention of exposure of the joint fitting are achieved, and the rigidity of the joint is also improved. The flexibility to handle the directional forces is insufficient.
[0008]
On the other hand, the technique described in Patent Document 2 is considered to have some flexibility because it is integrated by applying a prestress to a wide range in the axial direction. However, there is a problem that the work is troublesome because the work for tension is performed on site.
[0009]
In view of the above problems, the present invention provides a concrete member capable of improving the rigidity and flexibility as a whole of a building while reducing work on site when joining concrete members. With the goal.
[0010]
[Means for Solving the Problems]
The concrete member according to claim 1 is a concrete member used by being connected in a predetermined direction, wherein a pair of joint portions are provided on both end surfaces of the concrete member in the predetermined direction, and the concrete members are adjacent by the joint portion. A tension member for connecting the pair of joints is provided inside the concrete member, and a prestress is introduced into the concrete member by tensioning the tension member. It is characterized by.
[0011]
According to the first aspect of the present invention, the tension members of the concrete members are connected to each other via the joint portion by connecting the adjacent concrete members by the joint portion. As a result, a reinforcing structure extending continuously in the predetermined direction is formed inside the building constructed by connecting the concrete members in the predetermined direction. Therefore, the rigidity and flexibility of the entire structure are enhanced, and the structure can withstand external forces from various directions. In addition, since the joint portion and the tension member have an integral structure, the structure is simplified, and the number of parts and the number of steps in manufacturing are reduced. Since the joint portion is formed on the end face, it is not exposed to the other surface, so that it is not necessary to perform a medical treatment, and the labor of the work is reduced, and the rigidity of the joint portion is improved.
[0012]
According to a second aspect of the present invention, in the concrete member according to the first aspect, the joint portion includes a fitting buried in the end face of the concrete member, and a fitting member attached to the fitting. The attachment is connected to the tension member.
According to the second aspect of the present invention, since the joint portion is formed by attaching the joint member to the fixture buried in the end face of the concrete member, the joint member is damaged during the production of the concrete member. Is prevented.
[0013]
According to a third aspect of the present invention, in the concrete member according to the first or second aspect, the tension member is a rod.
According to the third aspect of the present invention, since the tension member is a rod, the rigidity and flexibility of the constructed structure as a whole are improved.
[0014]
A concrete member according to claim 4 is the invention according to any one of claims 1 to 3, wherein the pair of joint portions constitute a simple engagement joint that engages with each other by placing both at an engagement position. It is characterized by doing.
According to the fourth aspect of the present invention, the concrete members are aligned and the joints are placed at the engagement positions, whereby the joints engage with each other and connect the concrete members together.
[0015]
In a concrete member according to a fifth aspect, in the invention according to the fourth aspect, the pair of joints is formed by a male joint and a female joint, and the engaging surfaces of the male joint and the female joint are provided on the engagement surfaces thereof. A ridge is formed to allow insertion and prevent removal.
In the fifth aspect of the present invention, the concrete member is moved, and the male joint is inserted into the female joint, whereby the two are engaged in a state where they are prevented from coming off, and the concrete members are connected to each other.
[0016]
A concrete member according to a sixth aspect is characterized in that, in the invention according to any one of the first to fifth aspects, the concrete member has an anchor portion buried in concrete and a tubular portion opened to the end face.
In the invention described in claim 6, since the anchor portion is buried in the concrete and is firmly fixed, the tension by the tension member is reliably transmitted to the concrete, and a prestress is introduced into the concrete.
[0017]
A concrete member according to a seventh aspect is characterized in that, in the invention according to any one of the first to sixth aspects, the tension member is not substantially connected to the concrete member.
In the invention according to claim 7, since the tension member is not substantially connected to the concrete member, it can cope with external force by expanding and contracting and deforming independently of concrete.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a concrete member, a joint structure thereof, and a manufacturing method according to an embodiment of the present invention will be described with reference to the drawings.
1 and 2 are views showing a shield tunnel lining body constructed using a concrete segment which is a concrete member according to an embodiment of the present invention, and FIG. FIG. 2 is a perspective view seen from the face side.
This shield tunnel lining has a circular cross section, and as shown in FIGS. 3 and 4, concrete segments 1a, 1b, 1c, 1d, 1e divided into five in the circumferential direction are assembled in an annular shape. Are arranged in a large number in the axial direction.
[0019]
Among the concrete segments 1a, 1b, 1c, 1d, and 1e (hereinafter, denoted by 1 when there is no need to specify them), four concrete segments 1a, 1b, 1c, and 1d have a center angle in the circumferential direction of about It is a large concrete segment of 84 °, and one concrete segment 1e is a small concrete segment having a central angle of 24 °, and is closed circularly by these. The small concrete segment 1e is a final assembled concrete segment. After the other large concrete segments 1a, 1b, 1c, and 1d are erected, the small concrete segment 1e is moved by moving in the axial direction from the face side, and the five concrete segments are circular. Is closed. The small concrete segment 1e has a narrower width on the entrance side than the face side, and has a wedge function of pushing and widening a gap between the concrete segments 1a and 1d at the time of attachment.
[0020]
Each concrete segment 1 is provided with a tension / connection structure 3 for performing axial connection and applying prestress to the concrete segment 1 in the axial direction. The tension / connection structures are arranged on each concrete segment 1 so as to be equally spaced in the circumferential direction in a state where the concrete segments 1 are assembled in an annular shape. The number of arrangements of the tension and connection structures is a number that is balanced with the total tensile force applied to the concrete member joint. In the illustrated example, 3 is arranged on the large concrete segment 1 and 1 is arranged on the small concrete segment 1, whereby the annular assembly 2 is arranged at every central angle of 24 °.
[0021]
As shown in FIG. 5, the tensioning / connection structure 3 includes a pair of fittings 4 a and 4 b embedded in the axial end surface of the concrete segment 1, a tensioning member 5 inserted through the inside of the concrete segment 1, and each fitting 4 a , 4b respectively (male side joint 6a, female side joint 6b). The fittings 4a, 4b and the joint members 6a, 6b form joints 7a, 7b, respectively. As shown in FIG. 6, the tension member 5 is a rod-shaped member made of metal, resin, or another material (steel in this example) having elasticity and rigidity, and female screws 5a, 5b are formed at both ends, thereby forming an end portion. Are connected to the fixtures 4a and 4b, respectively. Therefore, when tension is applied to the tension member 5, the reaction force compresses the concrete in the axial direction and prestresses the concrete segment 1.
[0022]
As shown in FIG. 7A, a connecting pin 6a (male side joint, see FIG. 8) made of metal, ceramics, or another material is attached to the attachment 4a on the face side (left side in FIG. 5) of the concrete segment 1. As shown in FIG. 7 (b), a female joint 6b is provided on the mounting tool 4b that is attached and is on the entrance side (the same right side). Each of the fixtures 4a and 4b has disk-shaped anchor portions 11 and 12 and cylindrical portions 13 and 14. Each anchor portion 11 and 12 has a circular hole through which the tension member 5 is inserted. ing. Each of the anchor portions 11 and 12 is formed to have a relatively large diameter so as to secure a sufficient pressure receiving area.
[0023]
The cylindrical portion 13 of the male-side fitting 4a is provided with a small-diameter screw portion 15 on the bottom side and a large-diameter screw portion 16 on the open end side, each having an internal thread formed on the inner surface. A male screw portion 17 at the tip of the tension member 5 protruding from the circular hole of the anchor portion 11 is screwed to the small diameter screw portion 15, thereby fixing the fixed side of the tension member 5. The large-diameter screw portion 16 is screwed and fixed with a male screw portion 18 on the base end side of the connecting pin 6a inserted from the open end of the cylindrical portion 13. A seat 19 that receives the base end face of the connecting pin 6a is formed by a step at the boundary between the small diameter screw portion 15 and the large diameter screw portion 16. Thus, the connecting pin 6a and the tension member 5 are connected via the attachments 4a and 4b.
[0024]
The cylindrical portion 14 of the female attachment 4b has a small-diameter portion 21 on the bottom side and a large-diameter portion 22 on the opening side. Inside the small diameter portion 21, a tension nut 24 that is screwed into a male screw portion 23 at the tension side end of the tension member 5 protruding from the anchor portion 12 is housed. The axial length of the small diameter portion 21 is larger than the thickness of the tension nut 24. A cylindrical case 25 that accommodates the female joint 6b is inserted into the large diameter portion 22. A seat 26 that receives the base end of the case 25 is formed by a step at the boundary between the small diameter portion 21 and the large diameter portion 22.
[0025]
The case 25 has a small-diameter screw portion 27 on the bottom side, an intermediate large-diameter portion 28, and a large-diameter screw portion 29 on the opening end side. The small diameter screw portion 27 is screwed to the male screw portion 23 of the tension member 5 to fix the case 25. As shown in FIG. 9, the large diameter portion 28 accommodates a sleeve 32 in which sleeve pieces 31 divided in the circumferential direction are coaxially arranged. The sleeve 32 has an O-ring 33 mounted in a recess 32a formed on the outer peripheral surface thereof. A seat 34 that receives the base end of the sleeve 32 is formed by a step at the boundary between the small diameter screw portion 27 and the large diameter portion 28. A lid member 35 for preventing the sleeve 32 from jumping out is screwed into the large diameter screw portion. The case 25, the sleeve 32, and the O-ring 33 constitute a female joint 6b.
[0026]
The sleeve 32 is used as a pair with the connection pin 6a screwed and attached to the male attachment 4a to form a so-called one-touch joint (simple engagement joint). That is, as shown in FIGS. 9 (d) and 8 (b), the circumferential grooves 36 and 37 having a sawtooth shape in the longitudinal section are formed on the inner peripheral surface of the sleeve 32 and the outer peripheral surface of the connecting pin 6a. And ridges 38 and 39 are formed. These protrusions 38, 39 have front surfaces 40, 41, that is, a surface 40 facing the opening side in the sleeve 32, and a surface 41 facing the front end side in the connecting pin 6a, and a rear side, that is, a bottom side of the sleeve 32. And it inclines toward the base end side of the connecting pin 6a. On the other hand, the rear surfaces 42 and 43, that is, the surface 42 on the bottom side of the sleeve 32 and the surface 43 on the base end side of the connecting pin 6a are orthogonal to the axis. Therefore, when the connecting pin 6a is inserted into the sleeve 32, the wedge action of the connecting pin 6a by the wedge 39 causes the sleeve piece 31 to be expanded or the protrusion 38 of the sleeve 32 is elastically deformed, and the connecting pin 6a Allow insertion. On the other hand, in the direction in which the connecting pin 6a is pulled out, the rear surfaces 42, 43 of the ridges 38, 39 are engaged with each other, so that movement is hindered. Therefore, by simply inserting the connection pin 6a, the connection pin 6a is joined to the sleeve 32 in a state where it is prevented from coming off, and a simple and strong joint, a so-called one-touch joint is formed.
FIG. 10 is a sectional view showing a state where the concrete segments 1 are connected.
[0027]
Hereinafter, a manufacturing process of the concrete segment 1 having the tension / connection structure 3 described above will be described.
When the concrete segment 1 is manufactured, the anchor portions 11, 12 and the cylindrical portions 13, 14 of the male and female attachments 4a, 4b, and both ends thereof are fixed to the concrete casting formwork. The tension member 5 is assembled. At this time, a release agent such as grease is applied to the outer peripheral surface of the tension member 5. Thereby, after the concrete is solidified, the fixtures 4a, 4b are buried in the concrete on the end face of the concrete segment 1, and the tension members 5 are substantially separated from the concrete (unbonded state) with the fixtures 4a, 4b. (See FIG. 11). Therefore, the tension member 5 can expand and contract independently of concrete.
[0028]
After the concrete solidifies and reaches a predetermined strength, the tension member 5 is tensioned using a tension jack, and the tension nut 24 is tightened and fixed, thereby introducing prestress into the concrete segment 1. The tension at this time is 70% or less of the tensile load value of the tension member 5, and the amount of tension is, for example, 0.1% which is one fourth of 0.4% of the theoretical maximum elongation in the case of steel. Set to. This set amount can be set by measuring the elongation of the tension member 5 with respect to the natural length, and can be simply set by converting the rotation amount of the tension nut 24. In this way, by giving a tension with a margin to the elongation at break of the material, for example, the lining body is bent and deformed due to land subsidence or the like, and even if a further elongation stress is applied to the tension member 5, the tension is within the elastic deformation range. Thus, it can be elongated and deformed by 0.3% at the maximum.
[0029]
Next, the joint members 6a, 6b are mounted on the mountings 4a, 4b. A case 25 is mounted inside the cylindrical portions of the female mounting tools 4a and 4b. That is, the small diameter screw portion 27 of the case 25 is screwed into the male screw portion 23 of the tension member 5 until the bottom surface of the case 25 contacts the seat 34 of the tubular portion 14. Next, the three sleeve pieces 31 and the O-ring 33 surrounding the outer peripheral surface are attached to the large diameter portion of the case 25, and the lid member 35 is screwed into the large diameter screw portion 29. The connecting pin 6a is attached to the male mounting member 4a by screwing the male screw portion 18 on the base end side of the connecting pin 6a to the large-diameter screw portion 16 of the tubular portion 13.
[0030]
Next, a process of assembling the annular assembly 2 using the concrete segment 1 having the tension / connection structure 3 configured as described above will be described.
In this embodiment, as shown in FIG. 2, a step of attaching concrete segments 1 one by one to the face side end face of the already assembled assembly 2 is performed. At this time, the concrete segments 1 to be newly attached and the constructed concrete segments 1 are attached, for example, at a predetermined angle in the circumferential direction so that the circumferential positions of the concrete segments 1 and the constructed concrete segment 1 are not aligned. Thereby, as shown in FIG. 2, the circumferential joining surface of one assembly 2 is covered by the end surface of the concrete segment 1 of the adjacent assembly. That is, since the joining surfaces are not continuous linearly in the axial direction, the strength against the external force in the shearing direction is improved, and the waterproofness is also improved.
[0031]
To connect the concrete segment 1 to the existing assembly 2, the concrete segment 1 is held, and the connecting pins 6a protruding from the end face thereof are aligned with the positions of the attachments 4a, 4b opening to the end face of the assembly. You only have to push them until they come into contact. As a result, the connecting pin 6a moves forward while expanding the diameter of the divided sleeve 32 or elastically deforming the ridge 38 of the sleeve 32, and is connected to the sleeve 32 in a state where it is prevented from falling off. Next, the concrete segment 1 circumferentially adjacent to the attached concrete segment 1 is attached to the existing assembly 2 in a similar process. In this case, the concrete segment 1 to be attached may be moved in the axial direction while the circumferential end face is supported by the existing concrete segment 1. Finally, the tapered small concrete segment 1e is attached by pushing it into the tapered gap formed between the existing concrete segments 1a and 1d. Also in this case, the joints are spontaneously joined together just by pushing the concrete segments 1 together.
[0032]
As described above, according to the present invention, since the concrete segment 1 is directly attached to the assembly 2, the number of steps can be reduced as compared with the case where the assembly 2 is assembled and then joined. In addition, since the one-touch joint to which the concrete segment 1 is joined simply by pushing is used, the work is simple.
[0033]
In the tunnel lining body constructed in this manner, the tension members 5 for applying prestress to each concrete segment 1 are connected in the axial direction via the attachments 4a and 4b, and the entire length of the lining body A reinforcing material extending therethrough. Further, since the concrete segments 1 are joined while being shifted by a predetermined angle in the circumferential direction, integrity in the circumferential direction is also ensured. Therefore, the rigidity of the entire lining body is enhanced and the flexibility is also enhanced, so that a continuous underground flexible structure is constructed.
[0034]
For example, when the ground in the construction area subsides and the lining body flexes as a whole, a tensile stress is applied to the concrete segment 1 below the lining body and a compressive stress is applied to the upper concrete segment 1. Hang on. Since the compressive stress is applied by the concrete, the possibility that the tension member 5 is compressed and deformed is small. If the elongation due to the tensile stress is within the range of the prestress, no tensile stress is generated in the concrete, and the strength can be maintained. Therefore, even when land subsidence is expected, a highly durable building can be constructed.
[0035]
In the above description, only the configuration in which the concrete segments 1 are connected in the axial direction and the prestress is introduced is described, and the connection in the circumferential direction of the concrete segments 1 or the introduction of the prestress is not described. However, for this, an arbitrary method can be used. That is, a method of forming a bolt box on the circumferential end face of the concrete segment 1, a method of using an H-shaped bracket, a method of using unevenness fitted to the circumferential end face of the concrete segment 1 for alignment, and the like are used. In the case of fitting by unevenness, the recess may be formed in a long hole shape to allow movement in the axial direction at the time of connection by a one-touch joint.
[0036]
Further, a method described in Patent Document 1 can be used to apply a prestress due to the circumferential connection and tension of the assembly 2. That is, a duct extending in the circumferential direction is provided in each concrete segment 1, and a circular hole continuous in the circumferential direction is formed when the assembly is assembled, and a stranded wire-like tension member is inserted into the hole, thereby forming an inner surface of the assembly 2. Tension through the opening. Thereby, the circumferential prestress can be introduced into the assembly 2 and the circumferential bonding strength between the concrete segments 1 can be increased. When this method is adopted, a tension member passes through the concrete segment 1 vertically and horizontally, so that the concrete segment 1 needs a certain thickness.
[0037]
In the above-described embodiment, the connecting structure of the present invention is provided on the concrete segment 1 for forming the annular body. However, any concrete member that can be continuously connected in a predetermined direction can be used. Can be applied. For example, a box culvert, an arch culvert, a fume pipe, a propulsion pipe for a propulsion method, a U-shaped groove, a bridge girder used in the construction field, and the like, which are used in the field of water supply and sewerage and an electric power field.
[0038]
In the above embodiment, the joints 7a and 7b are constituted by the male joint 6a and the female joint 6b, which are joint members, and the attachments 4a and 4b embedded in concrete. The fittings 4a and 4b may be integrally formed to form a joint portion and buried in concrete. Further, in the above-described embodiment, as the material of the components of the fixtures 4a, 4b and the joint members 6a, 6b, metal, resin, ceramics, or a composite material of these, etc., depending on the required performance, is used. It can be adopted as appropriate.
[0039]
【The invention's effect】
As described above, in the present invention, the joint portion and the tension member are integrated, and the reinforcing structure extending continuously inside the building is formed. Therefore, the number of reinforcing materials embedded in the concrete member can be reduced. And the overall rigidity and flexibility of the construct is increased. Therefore, for example, even when a tunnel is buried underground, it is possible to construct a structure that can withstand an external force such as a bending force at the time of land subsidence. In addition, since the joint and the tension member are integrated and the joint is formed on the end face, the structure of the concrete member is simplified and the labor of the work is reduced. As a result, manufacturing and assembly costs are reduced. Can be reduced. In other words, since the bolt box is not used, the arrangement of the reinforcing members at the ends of the concrete member is not complicated, and the work is labor-saving.
[Brief description of the drawings]
FIG. 1 is a perspective view of a shield tunnel lining body using a concrete segment according to an embodiment of the present invention, as viewed from an entrance side.
FIG. 2 is a perspective view of the shield tunnel lining body of FIG. 1 as viewed from a face side.
FIG. 3 is a front view of the shield tunnel lining body of FIG. 1 as viewed from an entrance side.
FIG. 4 is a front view of the shield tunnel lining body of FIG. 1 as viewed from the face side.
FIG. 5 is a sectional view showing a tension / connection structure.
6A and 6B are views showing a tension member, wherein FIG. 6A is a front view and FIG. 6B is a side view.
FIGS. 7A and 7B are enlarged views of a main part of FIG. 5, in which FIG. 7A is a front side and FIG.
8A and 8B are diagrams showing a connecting pin, wherein FIG. 8A is a front view and FIG. 8B is a sectional view.
9 (a) is a front view, FIG. 9 (b) is a left side view, FIG. 9 (c) is a right side view, and FIG. 9 (d) is a view taken along line AA of FIG. 9 (a). It is sectional drawing.
FIG. 10 is a sectional view taken along the line BB of FIG. 1;
FIG. 11 is a sectional view showing a concrete segment before a joint member is attached.
[Explanation of symbols]
1,1a-1e Concrete segment (concrete member)
2 Assembly 3 Tension / connection structure 4a, 4b Mounting tool 5 Tension member 6a Connection pin (male side joint, joint member)
6b Female side joint (joint member)
7a, 7b Joint parts 11, 12 Anchor parts 13, 14 Cylindrical part

Claims (7)

A concrete member used by being connected in a predetermined direction,
A pair of joints are provided on both end surfaces of the concrete member in the predetermined direction, and the joints join the adjacent concrete members together.
A concrete member, wherein a tension member connecting the pair of joints is provided inside the concrete member, and a prestress is introduced into the concrete member by tensioning the tension member. The said joint part has a fixture embedded in the said end surface of the said concrete member, and a joint member attached to the said fixture, The said fixture is connected to the said tension member, The said fitting part is characterized by the above-mentioned. 2. The concrete member according to 1. The concrete member according to claim 1, wherein the tension member is a rod. The concrete member according to any one of claims 1 to 3, wherein the pair of joint portions constitute a simple engagement joint that engages with each other by placing them at an engagement position. The pair of joints is composed of a male-side joint and a female-side joint, and a ridge that allows insertion of the male-side joint and prevents disengagement is formed on the engagement surfaces thereof. The concrete member according to claim 4, wherein The concrete member according to any one of claims 1 to 5, wherein the attachment has an anchor part buried in concrete and a tubular part opened to the end face. The concrete member according to any one of claims 1 to 6, wherein the tension member is not substantially connected to the concrete member.

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