JPH06173220A - Installing method for elastic bearing body for structure - Google Patents

Abstract

PURPOSE:To make the quantity of shearing deformation of a rubber bearing body after its final installation almost nothing corresponding to the dispersion of contraction even if the quantity of actual contraction of upper concrete structure disperses variously. CONSTITUTION:The upper and lower plates 5, 6 of a rubber bearing body 2 are temporarily fixed to a side block 7 and a supporting base 36, and an upper concrete structure 24 is constructed on the upper plate 5, and the temporary fixing between the upper plate 5 and the side block 7 is released to introduce prestress into the structure 24, and after introduction, the upper plate 5 is temporarily fixed to the side block 7 again. After leaving as they are for a fixed term, the temporary fixing between the upper and lower plates 5, 6 and the side block 7 and also the supporting base 36 is released, and the lower plate 6 is moved as far as a total of the quantity of elastic shortening of the structure 24 and the quantity of removing the shearing deformation of the rubber bearing body 2 and the quantity for compensating the shearing deformation of the rubber bearing body 2 estimated from the quantity of creep dry contraction after the introduction of prestress, and fixed to the supporting base 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to prestressing of a concrete structure when a concrete bridge girder or other concrete structure is erected on a support such as a pier via an elastic bearing for the structure. TECHNICAL FIELD The present invention relates to a method for installing an elastic bearing for a structure capable of absorbing elasticity shortening and creep drying shrinkage to significantly reduce shear deformation of the elastic bearing for a structure.

[0002]

2. Description of the Related Art As a method of installing this type of elastic support for a structure, as disclosed in, for example, Japanese Patent Laid-Open No. 63-315723, shearing of a rubber support for supporting a concrete superstructure such as a bridge girder is performed. In order to reduce the amount of deformation, it is known that the rubber bearing is moved following the contraction of the upper structure, and then the lower part of the rubber bearing is further forcedly moved in the contracting direction of the upper structure.

[0003]

However, the conventional method for installing the elastic bearing for a structure described in the above publication has the following problems.
The lower support plate, the lower locking member, and the lower part of the rubber layer are moved by a jack by an amount substantially equal to the remaining contraction amount of the upper structure, and the lower locking member is moved downward while being fitted to the lower support plate. , The lower locking member is inserted into the locking member drop-fitting locking hole in the base plate, so that it is approximately equal to the remaining contraction amount of the upper structure which is also the amount by which the lower support plate and the like are moved. The amount is limited by the position of this preformed locking member drop-fitting locking hole. Generally, the amount of shrinkage of concrete superstructure such as bridge girder varies depending on its composition, temperature, etc. Therefore, the lower locking member is dropped into the locking hole for fitting the locking member formed in advance as described above. Then, the lower support plate is fixed to the base plate, and the method of installing the elastic support for the structure in this way is not so problematic when the contraction amount of the concrete upper structure such as the bridge girder to be actually constructed can be accurately known in advance. However, since it is difficult for the above reasons, it can be said that it is almost impossible to make the amount of shear deformation of the rubber layer of the rubber bearing almost zero.

The present invention has been made in view of the above points, and an object of the present invention is to cope with the fact that the actual shrinkage amount of the upper concrete structure varies in various ways, and accordingly, after the final installation. An object of the present invention is to provide a method for installing an elastic bearing for a structure that can reduce the amount of shear deformation of a rubber bearing to almost zero.

[0005]

According to the invention, the object is to provide an elastic bearing for a structure comprising a rubber bearing and upper and lower plates respectively attached to the upper and lower surfaces of the rubber bearing. This is an installation method, in which the lower plate is temporarily fixed to the support base, the upper concrete structure is constructed on the upper plate, then horizontal prestress is introduced to the upper concrete structure, and this prestress is introduced. After leaving it for a certain period of time, after that, the temporary fixing between the lower plate and the support is released, and the amount of elasticity shortening due to prestressing of the upper concrete structure and the amount of creep dry shrinkage after the prestressing are applied to the rubber bearing body described above. In addition to the amount for removing horizontal shear deformation, the amount of creep dry shrinkage remaining after prediction of prestressing was used to predict the residual amount of creep dry shrinkage. By an amount to compensate for the horizontal direction of shear deformation, to move the lower plate in the horizontal direction is achieved by mounting method of a structure elastic support member for fixing the movement after bottom plate to the support base.

Further, according to the present invention, the object is to attach a rubber bearing, upper and lower plates respectively attached to the upper and lower surfaces of the rubber bearing, and a lower plate, and to the rubber bearing for the lower plate. A method of installing an elastic support for a structure, comprising: a side block that restricts horizontal movement of the upper plate above a certain level, wherein the lower plate is temporarily fixed to a support base and the upper plate is attached to the side block. Temporarily fix and build the upper concrete structure on the upper plate, then release the temporary fixing between the upper plate and the side block to introduce the horizontal prestress to the upper concrete structure, After the introduction of the upper plate, the upper plate is temporarily fixed to the side block again and left for a certain period of time. In addition to releasing the temporary fixation with the block, in addition to the amount of elastic shortening due to prestressing of the upper concrete structure and the amount of removing the horizontal shear deformation of the rubber bearing based on the amount of creep drying shrinkage after the introduction of prestress. In addition, the lower plate is moved in the horizontal direction by an amount that compensates for the horizontal shear deformation of the rubber bearing based on the residual creep dry shrinkage amount predicted from the creep dry shrinkage amount after the introduction of prestress, This is also achieved by the method of installing the elastic support for structures, in which the lower plate is fixed to the support after this movement.

In another aspect of the invention, the lower plate is directly fixed to the support by welding.

[0008]

In the present invention, before the lower plate is finally fixed to the support base, the horizontal direction of the rubber bearing is determined based on the amount of elastic shortening of the upper concrete structure due to prestress and the amount of creep dry shrinkage after the introduction of prestress. In addition to the amount of removing the shear deformation of the lower plate, an amount that compensates for the horizontal shear deformation of the rubber bearing based on the residual amount of creep dry shrinkage predicted from the amount of creep dry shrinkage after the prestress is introduced. Is moved horizontally. However, in the installation method of the elastic support for structures of the present invention, the horizontal movement amount of the lower plate is determined based on the information such as the composition of the actually constructed upper concrete structure. The amount of shear deformation of the rubber bearing can be made exactly zero.

The present invention will be described below in more detail with reference to specific examples shown in the drawings. The present invention is not limited to these specific examples.

[0010]

SPECIFIC EXAMPLE In FIGS. 1 to 3, an elastic support 1 for a structure of the present example includes a rubber support 2 and upper and lower surfaces 3 of the rubber support 2.
And upper and lower plates 5 and 6 mounted on the lower plate 6 and side blocks 7 mounted on the lower plate 6 for restricting the horizontal movement of the upper plate 5 with respect to the lower plate 6 above a certain level. ing.

The rubber bearing 2 of this embodiment is composed of a rubber elastic body 11
A plurality of thin reinforcing plates 12 embedded in the rubber elastic body 11 in a laminated manner, and upper and lower thick reinforcing plates 13 and 14 embedded in the upper and lower surfaces of the rubber elastic body 11, respectively.
Upper and lower thick reinforcing plates 13 and 14 by bolts 15
And upper and lower mounting plates 16 and 17 respectively fixed to the. The rubber bearing 2 may be a rubber elastic body 11 in which a lead plug that suppresses and absorbs a large shear displacement is further embedded.

A steel anchor member 23 is provided on the upper surface 22 of the upper plate 5 fixed to the upper mounting plate 16 by a bolt 21.
Are fixedly provided, and a steel anchor member 23 is embedded on the upper surface 22 to construct an upper concrete structure 24 such as a bridge girder. Upper plate 5
An engagement piece 25 for preventing the rubber bearing 2 from sliding in the horizontal direction is fitted to the upper plate 5 between the rubber bearing 2 and the rubber bearing 2. On both side surfaces of the upper plate 5, recesses 26 in which the upper portions of the side blocks 7 are arranged are formed.

A base plate 33 is arranged on the lower surface 32 of the lower plate 6 fixed to the lower mounting plate 17 by bolts 31, and the base plate 33 is a steel anchor bolt 34 embedded in a support base 34 such as a bridge pier. It is fixed to the support base 34 via a nut 35 and the like. An engagement piece 37 is fitted between the lower plate 6 and the rubber support 2 to prevent the rubber support 2 from sliding in the horizontal direction. The lower plate 6 is fixed to the base plate 33 by welding 37.

Each of the side blocks 7 has a base portion 41.
And a vertical wall portion 42 that is integrally erected from the base portion 41,
And a pair of reinforcing wall portions 43 welded to the base portion 41 and the vertical wall portion 42, and another pair of reinforcing wall portions 44 welded to the base portion 41, the vertical wall portion 42 and the reinforcing wall portion 43. The base 41 is fixed to the lower plate 6 by bolts 45, and an engaging piece 46 that prevents the base 41 from sliding in the horizontal direction is fitted between the base 41 and the lower plate 6.
The upper portions of the vertical wall portions 42 are arranged in the recesses 26, and each of the side blocks 7 has an upper portion of the vertical wall portion 42 when the upper plate 5 is displaced horizontally with respect to the lower plate 6 due to an earthquake or the like. Side wall surface 4 of upper plate 5 in recess 26
By abutting on 7, the lower plate 6 of the upper plate 5
The horizontal movement above a certain level is restricted.

The elastic support 1 for structure supports the upper concrete structure 24 on the support 36, and the horizontal displacement, the relative displacement such as the inclination, which occurs between the upper concrete structure 24 and the support 36 during an earthquake. Is allowed by shear deformation.

A method of installing the elastic support body 1 for a structure constructed as described above will be described with reference to FIGS. 4 to 11. When carrying out the installation method of the present invention, it is necessary to perform surface treatment on each of the lower surface 32 of the lower plate 6 and the upper surface 51 of the base plate 33 so that the sliding resistance between them will be low. good. First, the elastic support 1 for a structure is attached to a support base 36 by an anchor bolt 34.
It is placed on the base plate 33 fixed by the above.
The mounting position of the elastic support for structure 1 is eccentric from the central position of the base plate 33 in consideration of the elastic shortening amount due to prestress and the creep drying shrinkage amount after the prestress is introduced. Next, as shown in FIGS. 4 and 5, a pair of temporary fixing plates 56 having recesses 55 are prepared, and each recess 55 is provided with
The respective ends of the lower plate 6 of the rubber bearing 2 which is eccentrically arranged as described above are fitted to each other, and the temporary fixing plates 56 are fixed to the base plate 3 via the nuts 35 and the anchor bolts 34, respectively. The lower plate 6 of the elastic support 1 is temporarily fixed to the support base 36, and a wedge-type temporary fixing device 57 as shown in FIG. 6 is arranged between the upper portion of each side block 7 and the upper plate 5. The upper plate 5 is temporarily fixed to the side block 7.

The wedge type temporary fixing device 57 includes a wedge block 58.
And a plurality of adjustment blocks 59 and these blocks 58
And 59 are held in the recesses 26 between the side wall surfaces 47 and the side surfaces 60 of the vertical wall portions 42, respectively, and a pair of long plates 65 and 65 are connected to each other. The holder 61, which is formed by welding the connecting plate 66 and the side plate 67, is attached to the side surface of the upper plate 5 by the bolt 68 at one end and to the side surface of the reinforcing member 43 at the other end by the bolt 69. It should be noted that the wedge block 58 and the adjustment block 59 are formed by the side wall surfaces 47 and the side surfaces 60 of the vertical wall portion 42.
Are selected and arranged so that a small gaps 71 and 72 are formed between them. Note that the holder 61 is not shown in FIGS. 5 and 8.

In the state where the lower plate 6 is temporarily fixed to the base plate 33 and the upper plate 5 is temporarily fixed to the side block 7 as described above, concrete is then poured into the formwork formed on the upper plate 5. It is poured and the upper concrete structure 24 is constructed. After constructing the upper concrete structure 24, as shown in FIG. 7, the retainer 61 is then removed to remove the wedge block 58 and the adjustment block 59 so that the upper plate 5 can be horizontally displaced with respect to each side block 7. And then prestressing the upper concrete structure 24 in the horizontal direction, that is, in the X direction. By introducing this presto, the rubber bearing 2 of the elastic bearing 1 for structures is sheared and deformed in the X direction as shown in FIG. The upper plate 5 is temporarily fixed to the side block 7 by using the wedge-type temporary fixing device 57 again on the elastic support body 1 for structure that has been sheared. At this time, the wedge block 58 and the adjustment block 59 are selected and arranged so that the gaps 71 and 72 are the same. After the introduction of this pre-stress, the gaps 71 and 72 change based on the creep drying shrinkage amount, but the wedge block 58 and the adjustment block 59 are regularly exchanged so that the gaps 71 and 72 are constant, and at the same time. Record the creep dry shrinkage.

After the creep drying shrinkage approaches the end by repeating the above work, the wedge type temporary fixing device 57 is removed to release the temporary fixing between the side block 7 and the upper plate 5 as shown in FIG. The temporary fixing plate 56 is removed to release the temporary fixing between the lower plate 6 and the support base 36. When it is difficult to remove the temporary fixing plate 56, the lower plate 6 may be pushed by using the hydraulic jack 81 as appropriate. Next, in addition to the amount of elastic reduction of the upper concrete structure 24 due to prestress and the amount of horizontal shear deformation of the rubber bearing 2 based on the amount of creep dry shrinkage after the introduction of prestress, as described above. As shown in FIG. 10, the hydraulic jack 8 is provided in an amount that compensates the horizontal shear deformation of the rubber bearing 2 based on the residual creep dry shrinkage amount predicted from the recorded creep dry shrinkage amount after the prestress is introduced.
11, the lower plate 6 is pulled in the horizontal direction and moved so that the rubber support 2 is shear-deformed in the opposite direction as shown in FIG. It should be noted that the residual creep drying shrinkage amount can be predicted even better if temperature correction is performed.
In addition, the amount of horizontal movement of the lower plate 6 may be determined in consideration of the amount of expansion and contraction of the upper concrete structure 24 due to the temperature during movement. Further, when it is necessary to move each of the elastic support members for structures 1 installed on each of the plurality of support bases 36 to be eccentric as described above, in order not to apply a great force to the fixing point, The order of the elastic support 1 for structures to be eccentric is determined. After the above movement, the lower plate 6 is fixed to the support base 36 by welding 37 or the like, and the welded portion is supplemented.

According to the above-mentioned installation method, the residual amount of creep dry shrinkage is predicted from the amount of creep dry shrinkage after the introduction of prestress, and the lower plate 6 is adjusted based on the predicted amount of residual creep dry shrinkage. Since it is moved and finally fixed, the rubber bearing 2 of the elastic bearing for structure 1 is eccentric by a more accurate residual amount of creep drying shrinkage, and as a result, when the creep drying shrinkage is almost completed. Then, the shear deformation of the rubber bearing 2 becomes almost zero,
An even damping effect can be provided for vibrations and displacements such as earthquakes. Further, since the upper concrete structure 24 can be supported in a state where the shear deformation is almost zero, the bearing is stable.

Although the side block 7 is attached to the lower plate 6 and moved together with the lower plate 6 in the above specific example, instead of this, the side block 7 is first temporarily directly fixed to the base plate 33, and then the lower side of the base plate 33 is fixed. After the final fixing of the plate 6, the side block 7 may also be fixed to the base plate 33.

Although the wedge type temporary fixing device 57 is used in the above description, as shown in FIG. 12, the screw type temporary fixing device 93 is used which is composed of the screw shaft 92 having the blocking plate 91 fixed to one end thereof. The upper plate 5 may be screwed onto the upper plate 5 to temporarily fix the upper plate 5 to the side block 7. When such a screw type temporary fixing device 93 is used, the clearance can be adjusted only by rotating the screw shaft 92, so that the work can be performed extremely quickly.

[0023]

As described above, according to the present invention, the residual amount of creep dry shrinkage is predicted from the amount of creep dry shrinkage after the introduction of prestress, and the lower plate is set based on the predicted amount of residual creep dry shrinkage. Since it is moved and fixed, even if the actual shrinkage amount of the upper concrete structure varies, the rubber bearing can be eccentric by a more accurate residual creep dry shrinkage amount. When the creep drying shrinkage is almost finished, the shear deformation of the rubber bearing can be made almost zero, and a uniform damping effect can be provided against vibration and displacement such as earthquake.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional front view of an elastic support for a structure installed by the installation method of the present invention.

FIG. 2 is a partial cross-sectional side view of the elastic support for structures shown in FIG.

FIG. 3 is a plan view of the elastic support for structures shown in FIG.

FIG. 4 is an explanatory view of temporary fixing in the installation method of the present invention.

FIG. 5 is a front view of FIG.

FIG. 6 is a detailed perspective view of the wedge-type temporary fixing device shown in FIG.

FIG. 7 is an explanatory view when the prestress is introduced by removing the wedge type temporary fixing device in the installation method of the present invention.

FIG. 8 is an explanatory diagram of wedge-type temporary fixing after introducing prestress in the installation method of the present invention.

FIG. 9 is an explanatory diagram of removal of temporary fixing in the installation method of the present invention.

FIG. 10 is an explanatory diagram of a method of moving the lower plate in the installation method of the present invention.

FIG. 11 is an explanatory diagram of the movement amount of the lower plate in the installation method of the present invention.

FIG. 12 is a detailed perspective view of a screw type temporary fixing device in the installation method of the present invention.

[Explanation of symbols]

 1 Elastic support for structure 2 Rubber support 5 Upper plate 6 Lower plate 7 Side block 24 Upper concrete structure 36 Support stand

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ueki 1-4-1, Kasumigaseki, Chiyoda-ku, Tokyo Inside the Shuto Expressway Public Corporation (72) Inventor Shinichi Umakami 1-4-1, Kasumigaseki, Chiyoda-ku, Tokyo Inside the Shuto Expressway Corporation (72) Inventor Mitake Yutaka 1-4-1 Kasumigaseki, Chiyoda-ku, Tokyo Inside the Shuto Expressway Corporation (72) Hideo Arai 4 Sumitomo Construction Co., Ltd., 13 Arakicho, Shinjuku-ku, Tokyo In-company (72) Inventor Shutoli Kamiya 4 Sumitomo Construction Co., Ltd. 13-13 Araki-cho, Shinjuku-ku, Tokyo (72) Inventor Soichiro Kawahara 8 Kirihara-cho, Fujisawa-shi, Kanagawa OILES Co., Ltd.

Claims (3)

[Claims] 1. A method of installing an elastic bearing for a structure, comprising a rubber bearing and upper and lower plates respectively attached to the upper and lower surfaces of the rubber bearing, wherein the lower plate is temporarily used as a support base. Fix and build the upper concrete structure on the upper plate, then introduce horizontal prestress to the upper concrete structure, leave it for a certain period after introducing this prestress, then lower plate and support In addition to the amount to remove the horizontal shear deformation of the rubber bearing based on the amount of elastic shortening due to prestressing of the upper concrete structure and the amount of creep drying shrinkage after the introduction of prestress, Furthermore, the lower pre-stress is compensated by an amount that compensates for the horizontal shear deformation of the rubber bearing based on the residual amount of creep dry shrinkage predicted from the amount of creep dry shrinkage after the introduction of prestress. A method of installing an elastic support for a structure, wherein a seat is moved in the horizontal direction, and after this movement, the lower plate is fixed to a support base. 2. A rubber bearing, upper and lower plates respectively attached to the upper and lower surfaces of the rubber bearing, and a lower plate, the horizontal level of the upper plate of the rubber bearing being above a certain level with respect to the lower plate. A method of installing an elastic support for a structure, comprising: a side block that regulates movement in a direction; a lower plate is temporarily fixed to a support base, and an upper plate is temporarily fixed to the side block; To build the upper concrete structure, then release the temporary fixing of the upper plate and the side block to introduce the horizontal prestress to the upper concrete structure,
After the introduction of this pre-stress, the upper plate is temporarily fixed to the side block again and left for a certain period of time, after which the temporary fixing between the lower plate and the support and the temporary fixing between the upper plate and the side block are released, In addition to the amount of elastic shortening of concrete structures due to prestress and the amount of removing the horizontal shear deformation of the rubber bearing based on the amount of creep dry shrinkage after introducing prestress, the amount of creep dry shrinkage after introducing prestress A structure in which the lower plate is moved in the horizontal direction by an amount that compensates the horizontal shear deformation of the rubber bearing based on the residual amount of creep dry shrinkage predicted from the above, and after this movement, the lower plate is fixed to the support base. Installation method of elastic support for objects. 3. The method for installing an elastic support for a structure according to claim 1, wherein the lower plate is fixed to the support base by welding.