JP2011179175A - Prestressed concrete well and method of constructing bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a prestressed concrete well capable of efficiently constructing a high quality bridge, and also provide a method of constructing a bridge. <P>SOLUTION: This prestressed concrete well includes a cylindrical prestressed concrete well body 21 and a plurality of fixing parts 10 which project from the prestressed concrete well body 21 inward and to which a pier 3 can be attached. The plurality of fixing parts 10 correspond to prestressed concrete wells 20b arranged at intervals in the circumferential direction of the prestressed concrete well body 21. The fixing part 10 comprises a sloped surface part 15 tilted 90° or more relative to the axial direction of the prestressed concrete well body 21. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a PC well used for a PC well foundation and a method for constructing a bridge including the PC well foundation.

  Conventionally, as a method of constructing a bridge such as a viaduct, a method of constructing a bridge using a PC well foundation is known. Here, the PC well foundation is a foundation structure constructed by a well-known PC well construction method. The PC well construction method is a method of laminating a plurality of PC wells made of short cylindrical precast concrete while sequentially press-fitting into the ground. Then, a long cylindrical PC well foundation is constructed in the ground, the PC steel material is arranged over the entire axial length of the PC well foundation, and the whole PC well foundation is prestressed by tensioning it. It is a construction method.

  As a bridge using such a PC well foundation, what is shown in FIG. 8 is conventionally known (for example, Patent Document 1). The construction method of the bridge 101 according to the prior art shown in FIG. 8 includes a foundation construction process for constructing a plurality of PC well foundations 102 in the ground, a bridge pier fixing process for securing the pier 103 to each PC well foundation 102, and each bridge pier. 103 and an erection process for erection of the bridge superstructure 104 between them. Further, as shown in FIG. 9, the pier fixing step includes a temporary support base construction step in which concrete is placed and cured inside the PC well foundation 102 to construct the temporary support base 105, and the temporary support base 105 is A temporary placing step for temporarily placing the pier 103, and a concrete or mortar filling step for fixing the pier 103 to the PC well foundation 102 by placing and curing concrete or mortar 106 inside the PC well foundation 102. Yes.

  However, in the construction method of the bridge 101 as described above, in order to install the pier 103, it is necessary to perform a temporary support base construction process and wait for the concrete of the temporary support base 105 to harden. There was a problem that time would lengthen the construction period.

  Therefore, in order to solve such a problem, a bridge construction method using a PC well foundation described in Patent Document 2 has been conventionally known. In this bridge construction method according to the prior art, a PC well 120 as shown in FIG. 10 is used. The PC well 120 includes a cylindrical PC well main body 121 and a fixing portion 110 that protrudes inward from the PC well main body 121 and to which a bridge pier 203 can be attached. And, as shown in FIG. 6, the bridge construction method using the PC well 120 is a foundation for constructing a plurality of cylindrical PC well foundations 202 having fixed portions 110 on the inner peripheral surface using the PC well 120. A construction step S1 and a temporary fixing step S2 for temporarily fixing the pier 203 to each PC well foundation 202 by attaching the pier 203 to the fixing portion 110 are provided. In addition, this bridge construction method includes an installation step S3 in which a bridge superstructure 204 is installed between each pier 203, and concrete 180 is placed inside each PC well foundation 202 and cured to cure each pier 203. And a main fixing step S4 for main fixing to the PC well base 202. The erection process S3 is performed before or simultaneously with the main fixing process S4.

JP 2004-190266 A JP 2008-101394 A

  According to the configuration according to Patent Document 2 described above, the fixing portion 110 is provided in the PC well main body 121, and the bridge pier 203 is attached to the fixing portion 110, so that the bridge superstructure 204 is not waited for the concrete 180 to harden. Can be constructed, and the construction of the bridge 101 can proceed. As a result, the construction period can be shortened, but further improvements have been demanded from the viewpoint of work efficiency during construction and the quality of the bridges to be constructed.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a PC well and a bridge construction method capable of efficiently constructing a high-quality bridge.

  The present invention is a PC well for solving the above-mentioned problem, comprising a cylindrical PC well main body, and a plurality of fixing portions projecting inward from the PC well main body to which piers can be attached. Are fixedly spaced in the circumferential direction of the PC well body.

  Moreover, the structure provided with the inclined surface which inclined 90 degree | times or more with respect to the axial direction of the said PC well main body may be sufficient as the said fixing | fixed part.

  Moreover, this invention is a construction method of the bridge for solving the said subject, Comprising: Plural cylindrical PC well foundations which have the said some fixing | fixed part in an inner peripheral surface using one of the said PC wells are provided. A foundation construction step to construct, a temporary fixing step of temporarily fixing the pier to each of the PC well foundations by attaching piers to the plurality of fixing portions, and an erection step of constructing a bridge superstructure between the piers. And a main fixing step of fixing each of the piers to each of the PC well foundations by placing and curing concrete inside each of the PC well foundations, and the erection step is performed before the main fixing step. Or performed simultaneously.

  According to the above configuration, since the plurality of fixing portions in the fixing PC well are arranged at intervals in the circumferential direction of the PC well body, a space is provided between adjacent fixing portions inside the PC well body. (Opening) can be secured. Thereby, compared with the case where there is no opening, for example, a space for inserting and removing a member such as a bolt and a work space can be secured, so that work can be easily performed when the pier is attached to the fixed portion. As a result, field work at the time of bridge construction can be performed quickly and accurately. Further, in the main fixing step, when the concrete is filled into the PC well main body, the air in the fluidized concrete escapes from the opening, so that the formation of voids in the hardened concrete can be prevented. Thereby, the quality of the hardened concrete can be improved. Further, since the opening is filled with concrete, the concrete inside the PC well body can be firmly bonded. As a result, the pier can be securely fixed to the fixing portion. From the above, according to the present invention, a high-quality bridge can be efficiently constructed.

  According to the PC well and the bridge construction method of the present invention, a high-quality bridge can be efficiently constructed.

It is a side view of the bridge constructed | assembled by the construction method of the bridge which concerns on one Embodiment of this invention. It is AA sectional drawing of FIG. (A) BB sectional drawing of FIG. 2, (b) CC sectional drawing of FIG. It is sectional drawing which shows the principal part of PC well for fixation. It is sectional drawing which shows the principal part of PC well for fixation. It is process drawing which shows the procedure of the construction method of a bridge. It is sectional drawing which shows the principal part of the fixing PC well which concerns on other embodiment. It is a side view of the bridge constructed | assembled by the construction method of the conventional bridge. It is sectional drawing which shows the principal part of the conventional PC well foundation. It is sectional drawing of the bridge constructed | assembled by the other conventional bridge construction method.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view of a bridge constructed by a method for constructing a bridge according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 2 is a cross-sectional view taken along the line BB in FIG. 2, and FIG.

  As shown in FIG. 1, the bridge 1 includes a plurality of PC well foundations 2 buried in the ground, a plurality of bridge piers 3 fixed to the PC well foundations 2, and an upper part of the bridge constructed between the bridge piers 3. And a work 4.

  As shown in FIG. 2, the PC well foundation 2 includes a plurality of ordinary PC wells 20a and fixing PC wells 20b arranged in the ground, and has a cylindrical shape. The PC well foundation 2 includes a PC steel material 25, and prestress is introduced in the axial direction due to the tension of the PC steel material 25. The PC well foundation 2 is filled with bottom base concrete (not shown) at the bottom, and filled with earthen sand 70. In addition, the filling of the filling earth and sand 70 is not necessarily required, and may remain a cavity. The PC well foundation 2 is filled with a head concrete 80 for fixing the pier 3 at the top.

  The normal PC well 20a and the fixing PC well 20b are reinforced concrete members manufactured in advance in a factory. The normal PC well 20a includes a cylindrical PC well body 21. The fixing PC well 20b includes a cylindrical PC well main body 21 and a plurality of protruding fixing portions 10 protruding radially inward from the PC well main body 21. In the present embodiment, a plurality of the above-mentioned ordinary PC wells 20a are laminated along the axial direction, and the fixing PC well 20b is laminated on the ordinary PC well 20a, whereby the fixing portion 10 is provided on the inner peripheral surface. PC well foundation 2 is constructed.

  The plurality of fixing portions 10 are configured to project radially inward from the entire axial direction of the PC well main body 21 in a longitudinal sectional view. Further, as shown in FIG. 3, the plurality of fixing portions 10 are arranged at intervals in the circumferential direction of the PC well main body 21, so that the opening 26 is provided between the adjacent fixing portions 10. Is formed. Moreover, each fixing | fixed part 10 has protruded so that it may go to the central axis of the PC well main body 21 in planar view. The number, shape, and arrangement interval of the fixing portions 10 are not particularly limited and can be changed as appropriate.

  4 and 5 are cross-sectional views showing the main part of the fixing PC well 20b. As shown in FIG. 4, the fixing portion 10 is formed with a bolt hole 11 into which the anchor bolt 12 is inserted so as to penetrate along the axial direction of the PC well body 21. The bolt hole 11 may be formed in advance at a factory, or may be formed at a construction site of a bridge. Further, as shown in FIG. 5, the fixing PC well 20b includes a plurality of reinforcing bars 50 arranged therein. The plurality of reinforcing bars 50 are arranged along the axial direction and the circumferential direction of the fixing PC well 20b, and are combined in a lattice shape. In the portion where the fixing portion 10 is provided, a plurality of reinforcing bars 50 are also arranged in the radial direction of the fixing PC well 20b and combined in a lattice shape. Thereby, the fixing | fixed part 10 is comprised so that the load of the pier 3 can be supported. A plurality of reinforcing bars 50 are also arranged in the normal PC well 20a. The fixing portion 10 includes a flat surface portion 16 facing the one side in the axial direction of the PC well body 21 and an inclined surface portion 15 facing the other side in the axial direction. The flat surface portion 16 and the inclined surface portion 15 are arranged so as to face upward and downward, respectively, when the PC well foundation 2 is constructed. The flat portion 16 is formed to be horizontal, and is configured so that the pier 3 can be placed thereon. On the other hand, the inclined surface portion 15 is configured to be a surface inclined with respect to the axial direction of the PC well main body 21. Specifically, the angle X formed by the inclined surface portion 15 and the axial direction of the PC well main body 21 is configured to be 90 degrees or more.

  As shown in FIG. 2, for example, a steel pier having a box-shaped cross section can be used for the pier 3, and the base 3 is provided with a base plate 30 disposed horizontally at the lower end. The base plate 30 is installed on the fixing portion 10 and is temporarily fixed by the anchor bolts 12 inserted into the base plate 30 and the fixing portion 10. When the base plate 30 and the anchor bolt 12 are fixed, they are fixed by a known bolt and nut. On the other hand, when the anchor bolt 12 and the fixing portion 10 are fixed, the anchor bolt 12 is inserted into the bolt hole 11 of the fixing portion 10 and the bolt hole 11 is bonded by filling with an epoxy resin adhesive. it can. However, these fixing methods are not particularly limited.

  As the bridge superstructure 4, for example, one having a main girder portion 41 having a box-shaped cross section and a bracket portion 42 projecting laterally from the main girder portion 41 can be used. It is fixed to the upper end of the.

  Next, a bridge construction method will be described. FIG. 6 is a process diagram showing a procedure of a method for constructing a bridge. First, a foundation construction step (step S1) is performed for constructing a plurality of PC well foundations 2 having the fixing portion 10 on the inner peripheral surface using the fixing PC well 20b. Specifically, a plurality of ordinary PC wells 20a and fixing PC wells 20b are sequentially press-fitted into the ground on which each PC well foundation 2 is installed, and stacked along the axial direction to construct each PC well foundation 2. To do. The fixing PC well 20b is installed on the ordinary PC well 20a. The press-fitting of each of the PC wells 20a and 20b can be performed, for example, by a method of pressing to a predetermined depth using a ground anchor embedded in the ground as a reaction force. Further, a bottom base concrete (not shown) is placed inside the PC well foundation 2, and the filling soil 70 is filled on the bottom base concrete.

  Next, a temporary fixing step (step S2) is performed in which the pier 3 is temporarily fixed to each PC well foundation 2 by attaching the pier 3 to the fixing portion 10. Specifically, first, the base plate 30 of the pier 3 is installed on the fixing portion 10 of the fixing PC well 20b. Installation of the pier 3 can be performed, for example, by lifting the pier 3 with a crane. And the anchor bolt 12 is inserted in the base plate 30 and the fixing | fixed part 10, and it fixes to each. Thereby, the pier 3 is temporarily fixed to the PC well foundation 2. When the pier 3 is temporarily fixed to the PC well foundation 2, the installation position may be adjusted by moving the pier 3.

  Subsequently, an erection process (step S3) for erection of the bridge superstructure 4 between each pier 3 is performed. Specifically, the bridge superstructure 4 assembled in advance is installed between the piers 3 by installing them in a lump. Moreover, the bridge superstructure 4 may be constructed by being assembled on the spot. Moreover, you may install on the bridge pier 3 by jacking up the bridge superstructure 4.

  Also, each bridge pier 3 is permanently fixed to each PC well foundation 2 by placing and curing the head concrete 80 inside each PC well foundation 2 at the same time as or after the installation process (step S3). The main fixing step (step S4) is performed. Specifically, the head concrete 80 is filled on the medium-filled sand 70 inside the PC well foundation 2 and cured. Thereby, the anchor bolt 12 is fixed by the head concrete 80, and the pier 3 is completely fixed to the PC well foundation 2. Further, from the viewpoint of securing firmly, it is preferable to fill the fixing part 10 with mortar 81 and fix the anchor bolt 12 with the mortar 81 (see FIG. 2). Thus, the bridge 1 is constructed.

  According to the bridge construction method using the PC well according to the above embodiment, the plurality of fixing portions 10 in the fixing PC well 20b are arranged at intervals in the circumferential direction of the PC well main body 21. Inside the main body 21, a space (opening 26) can be secured between the adjacent fixing portions 10. Thereby, compared with a case where there is no opening, for example, a space for inserting and removing a member such as a bolt and a working space can be secured, and therefore, when the bridge pier 3 is attached to the fixed portion 10, the work becomes easy. As a result, field work at the time of bridge construction can be performed quickly and accurately. In particular, in the temporary fixing step, it is advantageous when a bolt hole is formed in the fixing portion 10 or when the position of the pier 3 is adjusted. Further, in the main fixing step, when the head concrete 80 is filled into the PC well main body 21, air in the fluidized concrete escapes from the opening 26, thereby preventing voids from being generated in the hardened concrete. Can do. Thereby, the quality of the head concrete 80 can be improved. Moreover, since the opening 26 is also filled with concrete, the concrete inside the PC well body 21 can be firmly bonded. As a result, the pier 3 can be reliably fixed to the fixing portion 10. From the above, according to the present invention, a high-quality bridge can be efficiently constructed.

  Moreover, since the fixing | fixed part 10 is provided with the inclined surface part 15 inclined with respect to the axial direction of the PC well main body 21, when filling the head concrete 80, the air in a fluid concrete is filled below the fixing | fixed part 10. Instead, it passes through the inclined surface portion 15. Thereby, it can prevent that a space | gap arises in the hardened concrete, and can fix with higher quality.

  Further, by fixing the anchor bolt 12 with an epoxy resin adhesive, temporary fixing can be performed quickly, and other members for temporary fixing can be omitted, and the cost can be reduced. Further, by drilling the bolt hole 11 at the construction site, the dimensional accuracy when fixing with the anchor bolt 12 can be improved. Further, when the fixing PC well 20b is divided and transported, the cost can be reduced.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect of this invention is not limited to the said embodiment.

  For example, in the above-described embodiment, the fixed portion 10 includes the inclined surface portion 15 that is inclined. However, the inclined surface portion 15 is not necessarily required, and may be configured as a horizontal surface.

  Moreover, in the said embodiment, although the fixing | fixed part 10 was the protrusion-shaped reinforced concrete provided in the internal peripheral surface of the PC well 20b for fixation, if the base plate 30 of the pier 3 can be fixed, the structure will be especially limited. Instead, as shown in FIG. 6, a steel plate attached to the upper end of the fixing PC well 20b may be used.

  In the above embodiment, the fixing PC well 20b is arranged on the uppermost part of the PC well foundation 2. However, if the bridge pier 3 can be fixed, the installation position is not particularly limited, and the fixing PC well 20b is placed on the fixing PC well 20b. Ordinary PC wells 20a may be arranged.

  Moreover, in the said embodiment, although the fixing | fixed part 10 protruded from the whole axial direction of the PC well main body 21, it is not limited to this structure, You may be provided in a part of the axial direction of the PC well main body 21. .

DESCRIPTION OF SYMBOLS 1 Bridge 2 PC well foundation 3 Bridge pier 4 Bridge superstructure 10 Fixing part 11 Bolt hole 12 Anchor bolt 15 Inclined surface part 20a Normal PC well 20b Fixing PC well 21 PC well main body 26 Opening part 30 Base plate 50 Reinforcing bar

Claims (3)

A cylindrical PC well body;
A plurality of fixing portions projecting inward from the PC well body and capable of attaching a pier,
The plurality of fixing portions are PC wells arranged at intervals in the circumferential direction of the PC well body.   2. The PC well according to claim 1, wherein the fixing portion includes an inclined surface inclined by 90 degrees or more with respect to an axial direction of the PC well body. Using the PC well according to claim 1 or 2, a basic construction step of constructing a plurality of cylindrical PC well foundations having the plurality of fixing portions on an inner peripheral surface;
A temporary fixing step of temporarily fixing the pier to each of the PC well foundations by attaching the pier to the plurality of fixing portions;
An erection process for erection of a bridge superstructure between the piers;
A main fixing step of fixing each pier to each PC well foundation by placing and curing concrete inside each PC well foundation;
The bridge construction method is characterized in that the erection step is performed before or simultaneously with the main fixing step.

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