JP4636416B2 - Seismic isolation device mounting structure on pile head and its mounting method - Google Patents

Description

  The present invention relates to a structure for attaching a seismic isolation device to a top surface of a pile head and a method for attaching the structure.

  Conventionally, when building a building, there is a structure in which a seismic isolation device is installed on a floor slab or a footing as a structure for installing the seismic isolation device. However, since such a construction method is costly, a method of installing a seismic isolation device directly on a pile has been developed. In particular, in the case of a cast-in-place pile, since it is relatively easy to make the outer diameter of the pile larger than the outer diameter of the column, it is common to install a seismic isolation device directly on the pile.

  However, in the case of ready-made piles, when one column load is large, most of them are supported by several piles. In this case, as shown in FIG. 8, a footing 42 is installed on the piles 41, 41, and a pillar 44 is installed thereon via a seismic isolation device 43. In recent years, with the emergence of high bearing capacity piles, there are an increasing number of structures that support one pillar load with one pile. However, even in this case, as shown in FIG. 9, in most cases, a footing 42 is installed on a pile 41 and a column 44 is installed thereon via a seismic isolation device 43. This is because it can be corrected by installing footings against pile core misalignment and pile inclination.

  However, this increases the construction period and costs. Therefore, in order to reduce costs, there is also a structure in which the seismic isolation device is installed on a pile driven in as a foundation without using floor slabs or footings. For example, it has a structure in which a cap is attached to the head of a pile and a seismic isolation device is installed thereon (Patent Document 1).

  As shown in FIG. 10, a hard plastic cap 51 having an inner diameter that can be put on the upper end of the pile or a hard plastic cap 51 is put on the upper end of the pile 52, and the outer diameter of the cap is placed on the cap. The elastic block body 53 (seismic isolation device) having a rubber-like elasticity having an outer diameter equal to is installed.

Further, as shown in FIG. 11, the elastic block 53 (the seismic isolation device) is easily broken by deformation at the time of earthquake, but is strong enough to prevent compressive deformation due to the building weight in normal times. The cap 54 may be installed on the elastic block body 53 (the seismic isolation device) so that the open side is up.
JP 2004-324380 A

  However, with such a seismic isolation device mounting structure, when the pile is tilted, the upper surface of the elastic block body is not horizontal, which greatly affects what is installed on the elastic block body.

  Moreover, when installing the pillar of a building on a pile, the pillar and the core of a pile do not correspond, and what is called a pile core shift | offset | difference may be caused. As a result, an eccentric bending moment is applied to the rubber-like elastic body, and the deformation of the rubber-like elastic body may exceed the elastic limit. In addition, there is a possibility that the original performance of the rubber-like elastic body cannot be exhibited. In addition, it takes considerable time and cost to correct the piles at high and low levels.

  In view of such a conventional problem, the present invention has been made for the purpose of providing a structure for attaching a seismic isolation device at a pile head that can reduce the effects of so-called pile misalignment and pile inclination.

  The feature of the invention described in claim 1 for solving the conventional problems as described above and achieving an intended purpose is a seismic isolation device mounting structure that is mounted on a pile head, from the bottom plate and the periphery of the bottom plate. A seismic isolation device mounting form with an open top surface provided with a surrounding wall is fixed to the pile head of the pile, and a seismic isolation device of a size that can move horizontally is accommodated in the seismic isolation device mounting form. The gap between the seismic isolation device and the seismic isolation device mounting form is filled with a filler.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the pile is cylindrical and has a hollow portion, and the bottom plate is formed in a disk shape having a diameter larger than the outer diameter of the pile. In addition, the center of the bottom plate has a downward convex part that fits into the hollow part of the pile, and the peripheral wall is formed in a cylindrical shape.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the filler is made of a non-shrink grout material, and the standard compressive strength of the non-shrink grout material is 28 days old. The strength is 40 N / mm 2 or more.

  The feature of the invention described in claim 4 is that, in addition to the structure described in any one of claims 1 to 3, a seam material for adjusting the degree of horizontality is inserted between the pile and the formwork for attaching the seismic isolation device. Or it is to intervene.

  According to a fifth aspect of the present invention, in addition to the structure according to any one of the first to fourth aspects, the seismic isolation device mounting form is perforated in an end plate of a pile head of the pile. It exists in being fixed to the said pile by the volt | bolt standingly installed in the bolt hole, or the volt | bolt attached to the head side surface of the said pile.

A feature of the invention described in claim 6 is that the seismic isolation device in the seismic isolation device mounting structure according to any one of claims 1 to 5 has an open top surface including a bottom plate and a peripheral wall rising from the periphery of the bottom plate. The seismic isolation device and the seismic isolation device mounting mold are installed in the seismic isolation device mounting form by adjusting the horizontal position, height and level of the seismic isolation device using positioning means. A gap formed between the frame and the frame is filled with a filler, and the seismic isolation device is integrated with the mold for mounting the seismic isolation device.

  A feature of the invention described in claim 7 is that the positioning means is provided with a plurality of support shafts for adjusting the installation height and levelness of the seismic isolation device and supporting the seismic isolation device, The height and level of the seismic isolation device supported by the support shaft are determined by adjusting the mounting position of the seismic isolation device with respect to the support shaft.

  In the seismic isolation device installation structure and the mounting method thereof in the pile head according to the present invention, the seismic isolation device installation structure is attached to the pile head, and includes a bottom plate and a peripheral surface rising from the periphery of the bottom plate. A seismic device mounting form is fixed to the pile head of the pile, and a seismic isolation device of a size that can move in a horizontal direction is accommodated in the seismic isolation device mounting form, the seismic isolation device and the seismic isolation device Since the gap between the mounting formwork is filled with a filler, the position where the seismic isolation device is installed can be adjusted within the formwork for mounting the seismic isolation device, so-called pile misalignment has occurred. Even in cases, it can be handled without any problem.

  Further, in the present invention, the bottom plate is formed in a disk shape having a diameter larger than the outer diameter of the pile, and has a downward convex portion that fits in the hollow portion of the pile at the center of the bottom plate, Since the peripheral wall is formed in a cylindrical shape, when installing the seismic isolation device formwork on the top of the pile head, install the seismic isolation device by fitting the convex part into the hollow part of the pile. The shear stress of the formwork can be increased.

  Furthermore, by using a non-shrink grout material as the filler, it is possible to suitably prevent fluctuations in the fixed position of the seismic isolation device after grout filling.

  Furthermore, by setting the standard compressive strength of the non-shrink grout material to a strength of 40 N / mm 2 or more according to the 28th material age, it is possible to more reliably withstand the load from the seismic isolation device.

  Further, when the pile is inclined by inserting and adjusting a seam material between the pile and the mold for mounting the seismic isolation device so that the mold for mounting the seismic isolation device is horizontal. Even if there is, the seismic isolation device can be installed horizontally.

  Furthermore, the seismic isolation device form is fixed to the pile by bolts erected in the bolt holes drilled in the end plate of the pile head or by bolts attached to the side of the pile head. As a result, the pile and the formwork for attaching the seismic isolation device are firmly fixed.

  In addition, the seismic isolation device is installed in the form for attaching the seismic isolation device by adjusting the horizontal position, height and level of the seismic isolation device using positioning means. Even if the pile is tilted or pile core misalignment occurs by filling the gap between the device mounting formwork with a filler and integrating the base isolation device with the base isolation device formwork By adjusting the installation level and installation height of the seismic isolation device, they can be eliminated.

  Further, the positioning means is provided with a plurality of support shafts for adjusting the installation height and levelness of the seismic isolation device and supporting the seismic isolation device, and the support shafts stand on the bottom plate. By adjusting the mounting position of the seismic isolation device with respect to the support shaft, the height and level of the seismic isolation device supported by the support shaft are determined. Adjustments can be made and seismic isolation devices can be suitably installed.

  Next, embodiments of the present invention will be described based on the examples shown in FIGS.

  FIG. 1 shows a seismic isolation device mounting structure in a PHC pile head embodying the present invention. In this seismic isolation device mounting structure, the seismic isolation device mounting form 2 is installed on the head of the pile 1 that is the foundation of the building, and the seismic isolation device mounting form 2 is installed. A seismic isolation device 3 is installed in the formwork 2.

  The pile 1 is a PHC pile having a hollow portion. A steel end plate 1a having a bolt hole is fixed to the upper end surface of the pile. The end plate 1a is integrally provided with a flange 1b covering the outer periphery of the pile head.

  The seismic isolation device mounting form 2 installed on the head of the pile 1 has a bottom plate 4 and a peripheral wall 5 rising from its periphery, and has a flat plate shape with a flat bottom surface and an open top surface. The seismic isolation device 3 can be accommodated at an arbitrary position inside. The bottom plate 4 is formed in a disk shape having a diameter larger than the outer diameter of the pile 1, and a conical downward convex portion 6 that fits into the hollow portion of the pile 1 is integrally formed at the center thereof. Have. The peripheral wall 5 is formed in a cylindrical shape having the same diameter as the outer periphery of the bottom plate 4. In addition, the bottom plate 4 may have a polygonal shape in addition to the above-described circular shape. In this case, the peripheral wall 5 also has a rectangular tube shape that matches the outer peripheral shape of the bottom plate 4.

  As shown in FIG. 1, the seismic isolation device mounting form 2 is formed by erecting the form plate fixing bolts 7 a, 7 a... In the bolt holes drilled in the end plate 1 a of the pile 1. The pile 1 and the seismic isolation device mounting form 2 are fixed with nuts. That is, a plurality of bolt insertion holes 7b, 7b,... Are formed on the same circumference centered on the center of the bottom plate 4 as shown in FIG. ing. Further, the frame fixing bolts 7a, 7a,... Are erected on the end plate 1a of the pile 1 in accordance with the bolt insertion holes 7b, 7b,. And are fixed by screwing nuts 7c onto the mold fixing bolts 7a on the bottom plate 4 and fastening them. As the mold fixing bolts 7a, 7a..., Stud bolts may be used.

  The seismic isolation device 3 installed in the seismic isolation device mounting form 2 is of a size that can move in the horizontal direction in the seismic isolation device mounting form 2. As shown in FIG. 4, the seismic isolation device 3 includes two members, a concave member 11 having a concave curved surface portion 11a on the upper surface side and a convex member 12 having a convex curved surface portion 12a on the lower surface side. The radius of curvature of the portion 11a is larger than the radius of curvature of the convex curved surface portion 12a, and the convex curved surface portion 12a of the convex member 12 fits in the concave curved surface portion 11a of the concave mold member 11 so as to be swingable. A material in which a rubber-like elastic filler 13 that can be elastically deformed is interposed between the convex member 12 and the gap between the concave curved surface portion 11a and the convex curved surface portion 12a is used. In FIG. 4, reference numeral 14 denotes a pin for temporarily fixing the concave member 11 and the convex member 12, which is removed after the seismic isolation device 3 is fixed in the seismic isolation device mounting form 2.

  The seismic isolation device 3 is installed in the seismic isolation device mounting form 2 by positioning the concave member 11 of the seismic isolation device 3 in the seismic isolation device mounting form 2 by positioning means, A curable filler 15 made of a non-shrink grout material is injected into the gap between the seismic isolation device mounting mold 2 and the concave mold member 11 is inserted into the seismic isolation device mounting mold 2 through this filling. And integrated. The standard compressive strength of the grout material is preferably 40 N / mm 2 or more at the age of 28 days.

  When the structure 16 is supported by the seismic isolation device 3 thus fixed, a sliding material 17 is installed on the upper surface of the convex member 12 and placed on the seismic isolation device 3 as shown in FIG. The sliding plate 18 is fixed to the lower surface of the structure 16, the sliding plate 18 is brought into contact with the sliding material 17, and the structure 16 is supported thereon. Accordingly, the horizontal behavior of the structure 16 is allowed between the sliding material 17 and the sliding plate 18, and the behavior of the rotating direction of the vertical axis of the structure 16 is between the concave curved surface portion 11a and the convex curved surface portion 12a. Permissible.

  Next, a seismic isolation device mounting method for installing the seismic isolation device 3 on the head of the pile 1 will be described.

  First, the seismic isolation device mounting mold 2 is fixed to the head of the pile 1 already installed by the mold fixing bolt 7a and the nut 7c.

  Next, the seismic isolation device 3 is installed on the seismic isolation device mounting form 2 fixed to the pile 1. The seismic isolation device 3 is of a size that can move in the horizontal direction in the seismic isolation device mounting form 2 so that the mounting position of the seismic isolation device 3 can be freely selected to some extent.

  The seismic isolation device 3 is installed by adjusting the horizontal position, height and level of the seismic isolation device 3 using positioning means.

  The positioning means uses a plurality of support shafts for adjusting the installation height and levelness of the seismic isolation device 3 and supporting the seismic isolation device 3, and the support shafts are used for the seismic isolation device mounting type. The height and level of the seismic isolation device 3 supported by the support shaft are determined by standing on the bottom plate 4 of the frame 2 and adjusting the mounting position of the seismic isolation device 3 with respect to the support shaft.

  In this embodiment, as shown in FIGS. 1 and 3, the support bolts 21, 21,... Are used as the support shafts, and the support bolts 21, 21,. 2 by starting welding at a desired position on the bottom plate 4 and adjusting the positions of the height adjusting nuts 22, 22... Screwed to the support bolts 21, 21. Adjust the height and level.

  In the seismic isolation device 3, a predetermined number of support shaft insertion holes 23 are opened through a flange 11 b provided on the outer periphery of the concave member 11, and the support shaft erected on the bottom plate 4. After the end of the bolt 21 is inserted, the lower surface of the flange 11b is brought into contact with the height adjusting nut 22, and the height and the horizontality are adjusted by adjusting the height of the nut 22, and then the flange The concave member 11 is positioned so as to be immovable with respect to the seismic isolation device mounting form 2 by screwing a lock nut 24 onto the support bolt 21 from above 11b and tightening it onto the flange 11b.

  After positioning the seismic isolation device 3 in the seismic isolation device mounting form 2 in this way, a curable filler 15 is injected into the space between the seismic isolation device 3 and the concave member 11. Thus, the concave member 11 of the seismic isolation device 3 is integrated with the pile 1.

  As described above, the support bolts 21, 21,... Are attached to the seismic isolation device 3 without fixing the support bolts 21 to the bottom plate 4, and the base isolation bolts 21, 21,. It may be supported by… and installed in the seismic isolation device mounting form 2. In that case, the spindle insertion hole 23 of the seismic isolation device 3 may be a screw hole.

  In the above-mentioned embodiment, the case where the seismic isolation device is supported with respect to the concrete pile having the steel end plate on the pile top surface is described, but other steel pipe piles, or steel pipe concrete composite piles, etc. An embodiment for a pile having no bolt hole in the end plate at the upper end of the pile will be described with reference to FIG. Note that the same portions as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the case of the pile 32 having the steel pipe 31 on the outer periphery of the pile head, such as a steel pipe pile or a steel pipe concrete composite pile, the fixing bolts 33, 33,. The bolt insertion hole 7b is attached to the bottom plate 4 of the seismic isolation device mounting mold 2 at a position corresponding to the mold fixing bolts 33, 33,. , 7b... And by inserting the ends of the mold fixing bolts 33, 33... Into the bolt insertion holes 7 b, 7 b. The formwork 2 is fixed to the pile head.

  Other configurations and attachment methods are the same as those in the embodiment for the concrete pile 1 described above.

  In addition, in each Example mentioned above, the inclination of the pile 1 or the pile 32 installed in the ground is large, and it is inappropriate to adjust the level of the seismic isolation device only by adjusting in the mold base 2 for attaching the seismic isolation device. In that case, as shown in FIG. 7, a tapered seam material 35 may be interposed between the seismic isolation device mounting form 2 and the pile 1 or the pile 32. As the joint material 35, a steel liner or a non-shrink grout can be used.

  It should be noted that the liner may be formed in advance according to the actual inclination of the pile, in anticipation of the inclination of the pile, and may be formed in several types with different sizes. .

  In addition, it is good also as a positioning means by spanning a rod-shaped material over the upper end part of the surrounding wall 5 of the form 2 for seismic isolation apparatus attachment. This is because the seismic isolation device 3 is supported by the rod-shaped material spanned on the seismic isolation device mounting form 2, and the position and height of the seismic isolation device 3 are determined depending on the position and thickness of the rod-shaped material. , Which determines the level.

  Moreover, when the pile stays high or low, the height of the peripheral wall 5 of the seismic isolation device mounting form 2 and the installation height of the seismic isolation device 3 may be adjusted. In each of the above embodiments, the height of the installation position of the seismic isolation device 3 is adjusted by adjusting the lengths of the support bolts 21, 21... And the mounting positions of the height adjusting nuts 22, 22. Can be adjusted.

  In addition, when the position of the pile core deviates from the plan, as shown in FIG. 3, the installation position of the support bolts 21, 21,... By shifting in a horizontal direction from the position of the core, the seismic isolation device 3 can be installed at the planned position of the pile core.

It is a sectional side view which shows an example of the seismic isolation apparatus attachment structure which concerns on this invention. It is a top view which shows the seismic isolation apparatus attachment formwork used for the seismic isolation apparatus attachment structure which concerns on this invention. It is side sectional drawing which shows the other example of the seismic isolation apparatus attachment structure which concerns on this invention. It is sectional drawing which shows an example of the seismic isolation apparatus used for the seismic isolation apparatus attachment structure which concerns on this invention. It is side sectional drawing at the time of installing a structure on a seismic isolation apparatus in the seismic isolation apparatus attachment structure which concerns on this invention. It is a sectional side view which shows the example which installed the volt | bolt in the side surface of the pile in the seismic isolation apparatus attachment structure which concerns on this invention. It is a sectional side view which shows the case where the seam material is installed in the seismic isolation apparatus attachment structure which concerns on this invention. It is a side view which shows an example of the structure which installs a seismic isolation apparatus on the conventional footing. It is a side view which shows the other example same as the above. It is a sectional side view which shows an example of the conventional seismic isolation apparatus attachment structure. It is a sectional side view which shows the other example same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pile 1a End plate 1b Ridge part 2 Seismic isolation device installation form 3 Seismic isolation device 4 Bottom plate 5 Perimeter wall 6 Downward convex part 7a Formwork fixing bolt 7b Bolt insertion hole 7c Nut 11 Concave member 11a Concave surface part 11b Flange 12 convex member 12a convex curved surface portion 13 elastic filler 14 pin 15 filler 16 structure 17 slide material 18 slide plate 21 spindle bolt 22 height adjusting nut 23 spindle insertion hole 24 lock nut 31 steel pipe 32 pile 33 Bolts 34 for fixing the formwork Nut 35 Seams 41 Pile 42 Footing 43 Seismic isolation device 44 Column 51 Cap 52 Pile 53 Elastic block body (Seismic isolation device)
54 cylinder

Claims (7)

  A seismic isolation device mounting structure to be attached to a pile head, wherein a top-opening seismic isolation device mounting form having a bottom plate and a peripheral wall rising from the periphery of the bottom plate is fixed to the pile head of the pile, and the seismic isolation device A seismic isolation device having a size capable of moving in a horizontal direction is accommodated in a mounting mold, and a gap between the seismic isolation device and the seismic isolation device mounting form is filled with a filler. Seismic isolation device mounting structure at the pile head.   The pile is cylindrical and has a hollow portion, and the bottom plate is formed in a disk shape having a diameter larger than the outer diameter of the pile, and is downwardly fitted into the hollow portion of the pile at the center of the bottom plate. The seismic isolation device mounting structure according to claim 1, further comprising a convex portion, wherein the peripheral wall is formed in a cylindrical shape.   3. The seismic isolation device mounting structure according to claim 1, wherein the filler is made of a non-shrink grout material, and the reference compressive strength of the non-shrink grout material is 40 N / mm 2 or more at 28 days of material age.   The seismic isolation device mounting structure according to any one of claims 1 to 3, wherein a seam material for adjusting the degree of horizontality is inserted or interposed between the pile and the form for mounting the seismic isolation device.   The seismic isolation device mounting form is attached to the pile by a bolt installed in a bolt hole drilled in an end plate of the pile head of the pile or a bolt attached to a side surface of the head of the pile. The seismic isolation device attachment structure in any one of Claims 1-4 currently fixed. Positioning the seismic isolation device in the seismic isolation device mounting structure according to any one of claims 1 to 5 in an open top seismic isolation device mounting form having a bottom plate and a peripheral wall rising from the periphery of the bottom plate. The horizontal position, height and level of the seismic isolation device are adjusted by using means, and a gap formed between the seismic isolation device and the form for mounting the seismic isolation device is filled with a filler. A seismic isolation device mounting method for a pile head, wherein the seismic isolation device is integrated with the seismic isolation device mounting form. The positioning means is provided with a plurality of support shafts for adjusting the installation height and levelness of the seismic isolation device and supporting the seismic isolation device, and the mounting position of the seismic isolation device with respect to the support shaft The method of attaching a seismic isolation device to a pile head according to claim 6, wherein the height and level of the seismic isolation device supported by the support shaft are determined by adjusting the height of the shaft.

Images