JP2018200256A - Inspection method and performance determination method of laminated rubber support containing metal plug - Google Patents

Abstract

To provide an inspection method of a laminated rubber support containing a metal plug capable of inspecting the metal plug of the laminated rubber support containing the metal plug arranged at the bridge and the building in situ.SOLUTION: A laminated rubber support 1 containing a lead plug includes a lead plug 4 in a laminated body formed by alternately laminating a plurality of platy rubbers and copper plates. An X-ray is irradiated to the laminated rubber support 1 containing the lead plug on a side face of the laminated body from a direction at which a central axis Xa is tilted, and an X ray image is obtained by an imaging plate 13 installed on the side face orthogonal to the side face to which the X ray is incident. A distortion of the x-ray image acquired by the imaging plate 13 is modified based on a geometrical relationship between an irradiation path of the X ray and components of the laminated rubber support 1 containing the lead plug and an original shape of the components. A volume of the lead plug 4 is obtained from the image of the lead plug 4 in the X ray image in which the distortion is modified, and a damping performance of the lead plug 4 is obtained from this volume, and the performance left in the laminated rubber support 1 containing the lead plug is evaluated.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an inspection method for inspecting a laminated rubber bearing with a metal plug used in a bridge, a building, or the like in situ, and a method for determining the performance of the laminated rubber bearing with a metal plug.

  The support that supports the upper structure installed between the lower structure and the upper structure of bridges and buildings has rapidly spread since the Hyogoken-Nanbu Earthquake has occurred. Yes. As this type of bearing, there is known a laminated rubber bearing with a lead plug including a laminated body in which a plurality of layers of plate-like rubber and steel plates are alternately stacked, and a columnar lead plug disposed in the laminated body. ing.

  Laminated rubber bearings with lead plugs support the superstructure of bridges and buildings with laminates, move the superstructure in the horizontal direction during an earthquake, and restore the superstructure that has moved to the position before movement, Furthermore, it has a function of reducing the seismic force acting on the superstructure by extending the natural period. The lead plug also has a damper function that absorbs vibration energy and attenuates the shaking of the superstructure.

  After being installed in a bridge or a building, this lead rubber laminated rubber bearing is subject to various deteriorations and damages over time. Aged deterioration of laminated rubber bearings with lead plugs includes peeling of the laminated rubber and steel plate, peeling of the covering rubber covering the side surfaces of the laminated body or ozone deterioration, and damage to the lead plug. Among these aging deterioration, damage to the lead plug causes a reduction in the damper function, and thus greatly affects the performance of the laminated rubber bearing with the lead plug.

  As damage that occurs in a lead plug with the passage of time, cracks, fractures, and flow protrusions are known in order of increasing damage. Flow protrusion is a phenomenon that occurs when the lead forming the lead plug flows between the rubber of the laminate and the steel plate and is pushed out from the side, such as the load acting on the laminated rubber bearing with the lead plug, the deformation of the laminate, etc. It is thought to be caused by Laminated rubber bearings with lead plugs that have cracks, breaks, or flow protrusions in the lead plugs must be replaced promptly because the damper function of the lead plugs is greatly reduced.

  Until the flow protrusion occurs in the laminated rubber bearing with lead plug, lead plug deformation such as lead flow, cracking and fracture has occurred inside the laminate, and the damper function of the lead plug has already deteriorated. As a result, the performance of laminated rubber bearings with lead plugs has deteriorated. However, since the deformation of the lead plug occurring inside the laminated body cannot be detected from the appearance, it is impossible to detect the deterioration of the performance of the laminated rubber bearing with the lead plug until the flow protrusion occurs. Therefore, in order to detect the deterioration of the performance of the laminated rubber bearing with a lead plug at an early stage, a method for inspecting the deformation of the lead plug in the laminated body in a nondestructive manner is required.

  Conventionally, as a method for nondestructively inspecting a lead plug installed in a laminated body, an inspection method for confirming the soundness of a lead plug using an X-ray CT apparatus has been proposed (see Patent Document 1). This inspection method performs tomography in a non-destructive state using an X-ray CT apparatus in a state where the laminated rubber bearing with lead plugs is displaced in the horizontal direction while applying a vertical load to the laminated body. . The state of the interface between the lead plug and the laminated rubber is confirmed from the tomographic image of the laminated body obtained in this way, and the soundness of the lead plug is confirmed.

JP 2001-033402 A

  However, the above conventional method for inspecting lead plugs is carried out in the course of manufacturing laminated rubber bearings with lead plugs, and uses a large-scale X-ray CT apparatus with a device configuration, so lead installed in bridges and buildings. It cannot be applied to laminated rubber bearings with plugs. In addition, the conventional lead plug inspection method described above requires photographing with the laminated body displaced in the horizontal direction. However, the laminated rubber bearing with lead plug installed in the bridge or building is displaced in the horizontal direction. It is difficult to apply the conventional method.

  In addition, the conventional lead plug inspection method confirms the soundness of the lead plug based on the state of the interface between the lead plug and the laminated rubber. If the lead plug is unhealthy, the lead plug is included. It has not been studied at all how much performance of the laminated rubber bearing remains.

  Then, the subject of this invention is providing the inspection method of the laminated rubber bearing with a metal plug which can test | inspect the metal plug of the laminated rubber bearing with a metal plug installed in a bridge, a building, etc. in-situ. is there. Another object of the present invention is to provide a performance judging method for judging the performance remaining on the laminated rubber bearing with metal plug based on the inspection result of the laminated rubber bearing with metal plug.

In order to solve the above-described problems, the method for inspecting a laminated rubber bearing with a metal plug according to the present invention includes a laminated body in which a plurality of plate rubbers and steel plates are alternately laminated, and one side and the other side of the laminated body. A metal plug including a connection body disposed on the structure and connected to a structure; and a metal plug having a damper function extending through the lamination body and the connection body and extending to the lamination method of the plate rubber and the steel plate A method for inspecting laminated rubber bearings,
In the original position where the laminated rubber bearing with the metal plug is installed, the laminated body is irradiated with X-rays to obtain an X-ray image, and based on the contour shape of the image of the metal plug in the X-ray image. It is characterized by conducting an inspection.

  According to the above configuration, when the laminated rubber bearing with a metal plug is installed, for example, between the lower structure of the bridge and the upper structure, the connection body on one side of the laminated body and the connection body on the other surface become the lower structure. And connected to the superstructure, respectively. Therefore, the metal plug inside the laminated body cannot be inspected by its appearance at the original position where the laminated rubber bearing with the metal plug is installed. Here, the method for inspecting a laminated rubber bearing with a metal plug according to the present invention obtains an X-ray image by irradiating the laminated body with X-rays at the original position where the laminated rubber bearing with a metal plug is installed. There is no inconvenience that a tomographic image cannot be acquired due to the large-scale apparatus configuration as in the inspection method using the X-ray CT apparatus. Further, unlike the conventional inspection method using an X-ray CT apparatus, there is no need to deform the laminated rubber bearing with a metal plug, and the laminated body of the laminated rubber bearing with a metal plug may be irradiated with X-rays. Applicable to laminated rubber bearings with metal plugs in position. By using the X-ray image obtained in the original position in this way, it is possible to inspect the metal plug, which is impossible depending on the appearance of the laminate.

  Here, examples of the metal plug having a damper function include those formed of lead or tin, but may be formed of other metals as long as the damper function is achieved.

  Also, laminated rubber bearings with metal plugs include those installed in civil engineering structures such as bridges, those installed in buildings such as buildings, and those installed in plant facilities of various factories. .

  An inspection method for a laminated rubber bearing with a metal plug according to an embodiment corrects the X-ray image according to an X-ray incident position and / or an incident angle with respect to the laminated body.

  According to the above embodiment, the X-ray image is corrected according to the incident position and / or incident angle of the X-ray with respect to the stacked body, so that other structures and members existing at the original position become obstacles. Even when X-rays cannot be irradiated from the front of the laminate, the inside of the laminate can be accurately grasped and the metal plug can be accurately inspected. Further, when a plurality of metal plugs exist in the laminated body, images of the respective metal plugs can be taken without overlapping by adjusting the X-ray incident position and / or incident angle. In this case, each metal plug can be inspected accurately by correcting the X-ray image according to the X-ray incident position and / or incident angle.

  In one embodiment, the method for inspecting a laminated rubber bearing with a metal plug is based on the position of a mark previously set on the laminated body and the position of the mark image in the X-ray image. The photographing position of the X-ray photographing image in the laminated rubber bearing is specified.

  According to the embodiment, based on the actual position of the mark previously set on the laminate and the position of the mark image in the X-ray image, the laminated rubber bearing with the metal plug of the X-ray image is obtained. The shooting position at can be specified. Therefore, it is possible to accurately inspect the metal plug. Here, it is preferable that the mark is formed of a material having a lower X-ray transmittance than the stacked body. When a plurality of X-ray images includes the same mark image, the plurality of X-ray images are aligned based on the mark image, and the plurality of X-ray images are combined. It can be performed.

  In one embodiment of the method for inspecting a laminated rubber bearing with a metal plug, a plurality of the X-ray images are created by setting different incident positions and / or incident angles of X-rays with respect to the laminated body. A plurality of X-ray images are synthesized to create an X-ray image for inspection.

  According to the embodiment, a plurality of X-ray images are created by setting different X-ray incident positions and / or incident angles with respect to the stacked body. The X-ray incident position and incident angle are set to positions and angles at which the metal plugs in the laminate can be clearly imaged in each X-ray image. By synthesizing a plurality of these X-ray images to create an X-ray image for inspection, the metal plug in the laminate can be accurately imaged, and the metal plug is accurately inspected. Can do.

  In one embodiment of the method for inspecting a laminated rubber bearing with a metal plug, the X-ray image is binarized.

  According to the above-described embodiment, by binarizing the X-ray image, the metal plug image in the X-ray image can be made clear. Therefore, an accurate inspection of the metal plug can be performed. Here, the amount of X-ray transmission with respect to the members constituting the laminated rubber bearing with a metal plug is, for example, a relatively large amount of laminated rubber plate, while a relatively small number of steel plates and metal plugs. Accordingly, the binarization processing of the X-ray image, for example, the shape of each component member is sharp so that, for example, the plate-like rubber, the steel plate, and the metal plug can be clearly distinguished by the color difference of the image. Can be expressed as

The method for determining the performance of a laminated rubber bearing with a metal plug according to the present invention includes a step of estimating a volume of the metallic plug from an image of the metallic plug in the X-ray image obtained by the inspection method for the laminated rubber bearing with a metal plug. ,
A step of evaluating the attenuation performance of the laminated body in light of a correlation model indicating a correlation between the volume of the metal plug and the attenuation performance obtained in advance. Yes.

  According to the above configuration, the volume of the metal plug is estimated from the image of the metal plug in the X-ray image obtained at the original position of the laminated rubber bearing with the metal plug. The volume of the metal plug can be calculated by estimating the volume of the flow protrusion from the size of the flow protrusion of the metal plug appearing in the X-ray image, and subtracting the volume of the flow protrusion from the original metal plug volume. it can. The current volume of the metal plug represented in the X-ray image is obtained by illuminating the volume of the metal plug estimated in this manner with a correlation model indicating the correlation between the volume of the metal plug and attenuation performance obtained in advance. Can be obtained. The damping performance of the laminate can be evaluated based on the damping performance of the metal plug thus obtained. Accordingly, it is possible to effectively determine the performance remaining on the metal plug-containing laminated rubber bearing.

The method for determining the performance of a laminated rubber bearing with a metal plug according to the present invention includes a step of estimating a crack amount of the metallic plug from an image of the metallic plug in the X-ray image obtained by the inspection method for the laminated rubber bearing with a metallic plug. When,
A step of evaluating the damping performance of the laminate in light of a correlation model showing the correlation between the estimated amount of cracking of the metal plug and the amount of decrease in damping performance. It is characterized by having.

  According to the above configuration, the amount of cracks generated in the metal plug is estimated from the image of the metal plug in the X-ray image obtained at the original position of the laminated rubber bearing with the metal plug. The crack amount of the metal plug can be estimated from the thickness and length of the crack of the metal plug that appears in the X-ray image. The amount of cracking of the metal plug estimated in this way is represented in the X-ray image by illuminating a correlation model showing the correlation between the amount of cracking of the metal plug and the amount of decrease in attenuation performance obtained in advance. The current damping performance of the metal plug can be obtained. The damping performance of the laminate can be evaluated based on the damping performance of the metal plug thus obtained. Accordingly, it is possible to effectively determine the performance remaining on the metal plug-containing laminated rubber bearing.

It is a top view which shows the laminated rubber bearing with a lead plug to which the test | inspection method of embodiment of this invention is applied. It is sectional drawing of the laminated rubber bearing containing a lead plug. It is a figure which shows a mode that X-ray | X_line is irradiated to the laminated rubber bearing containing a lead plug. It is a schematic diagram which shows the relationship between the image of the lead plug in a radiography image, and the lead plug of the laminated rubber bearing containing a lead plug. It is a figure which shows the X-ray imaging image before correction | amendment. It is a figure which shows the X-ray image after correction | amendment. It is an X-ray imaging image in which the central axis of the X-ray is located on the upper part of the laminated rubber bearing with a lead plug. FIG. 6B is an X-ray image obtained by X-ray with the central axis positioned below FIG. 6A. FIG. 6B is an X-ray image obtained by X-ray with the central axis positioned below FIG. 6B. FIG. 6C is an X-ray image obtained by X-ray with the central axis positioned below FIG. 6C. FIG. 6D is an X-ray image obtained by X-ray with the central axis positioned below FIG. 6D. 6A is an X-ray image obtained by synthesizing portions of the X-ray images of FIGS. 6A to 6E. It is sectional drawing of the laminated rubber bearing with a lead plug from which the X-ray imaging image of FIG. 6A thru | or 6E was obtained. It is a graph which shows the fall of the damping performance with respect to the reduction | decrease of the volume of a lead plug.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view showing a laminated rubber bearing with a lead plug as a laminated rubber bearing with a metal plug to which the inspection method of the embodiment is applied, and FIG. 2 is a sectional view of the laminated rubber bearing with a lead plug. This laminated rubber bearing 1 with a lead plug is installed on a road bridge as a structure.

  This laminated rubber bearing 1 with a lead plug includes a laminate 2 formed by laminating a plurality of plate rubbers 7 and steel plates 8 alternately. This laminated body 2 has a rectangular parallelepiped shape with a square plane. The plate-like rubber 7 of the laminate 2 is made of natural rubber, and is adhered to the steel plate 8 by an adhesive or vulcanization adhesion. The plate rubber 7 may be made of a high-damping rubber obtained by adding various resins and fillers to natural rubber and / or synthetic rubber.

  On one surface of the laminated body 2, which is located on the upper side in FIG. 2, an upper connecting body 3 formed of a steel plate having a thickness larger than that of the laminated body 2 and connected to the upper structure of the structure is provided. Has been placed. Moreover, the lower connection body 3 connected to the lower structure of the structure is disposed on the other surface of the stacked body 2, which is the lower surface in FIG. 2. A plurality of fixing holes 10 into which bolts, dowel pins and the like for connecting to the structure are screwed are provided at the edge portions of the upper and lower connecting bodies 3.

  The side surface of the laminate 2 and the side surfaces of the upper and lower connecting bodies 3 are covered with a covering rubber 5 for preventing internal deterioration. The upper end of the covering rubber 5 is bent toward the plane side of the connection body 3 so as to surround the edge of the upper connection body 3. The covering rubber 5 can be formed of high damping rubber or natural rubber. Examples of the high damping rubber include ethylene propylene rubber, nitrile rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, isoprene rubber, styrene butadiene copolymer rubber, acrylonitrile butadiene rubber, butadiene rubber or silicone rubber, or a mixture thereof and natural rubber thereof. Can be used.

  In the laminated rubber bearing 1 with a lead plug, four through holes are formed through the upper and lower connecting bodies 3 and the laminated body 2 in the thickness direction, and metal plugs are formed in these through holes. Each of the lead plugs 4 is accommodated. The lead plug 4 is made of lead having a purity of 99.9% or more, and has a cylindrical shape with a central axis extending in the laminating direction of the plate-like rubber 7 and the steel plate 8 of the laminate 2. The lead plug 4 is disposed at a position forming a square apex on a diagonal line in the plan view of the laminated rubber bearing 1 with a lead plug. The lead plug 4 is press-fitted and accommodated in four through holes formed in the stacking direction of the stacked body 2 and the connecting body 3 after the upper and lower connecting bodies 3 are fixed to the stacked body 2. Has been.

  This laminated rubber bearing 1 with a lead plug is installed on a road bridge, and is disposed between a bridge pier as a lower structure and a bridge girder as an upper structure. The connection body 3 on the lower side of the laminated rubber bearing 1 with lead plugs is connected to an anchor bolt installed on the upper end surface of a steel or concrete pier. The upper connecting body 3 is connected to a bolt screwed to a lower flange of a steel or concrete bridge girder.

  Thus, the lead-plug laminated rubber bearing 1 installed on the pier and supporting the bridge girder is subjected to the dead load of the superstructure, the live load that fluctuates due to the passing of the vehicle, the wind load, the earthquake load, etc. To do. Further, vibrations due to passing of the vehicle, wind and earthquake are transmitted to the laminated rubber bearing 1 with lead plug. Furthermore, due to the expansion or contraction of the bridge member accompanying the temperature change, a displacement occurs between the upper connection body 3 and the lower connection body 3 of the laminated rubber bearing 1 with the lead plug. Due to these loads, vibrations and displacements, deformation may occur in the lead plug 4 in the laminated rubber bearing 1 with lead plug. As the deformation of the lead plug 4, breakage in which a cut surface is formed in the transverse direction at any position in the axial direction, or lead between the plate-like rubber 7 and the steel plate 8 of the laminated body 2 from the side surface of the lead plug 4. There is a flow that flows out. These deformations of the lead plug 4 cannot be detected from the appearance of the laminated body 2, but cause the performance of the laminated rubber bearing 1 with the lead plug to deteriorate. Therefore, the inspection method of the laminated rubber bearing with a metal plug according to the present embodiment performs a non-destructive inspection without destroying the laminated rubber bearing 1 with a lead plug, and detects the deformation of the lead plug 4.

  FIG. 3 is a schematic diagram showing a state in which the laminated rubber bearing 1 with a lead plug is inspected by the method for inspecting the laminated rubber bearing with a metal plug according to the present embodiment. The inspection method of this embodiment includes an X-ray source 12 that generates and emits X-rays, and an imaging plate 13 as an X-ray detector that detects X-rays emitted from the X-ray source 12 and transmitted through the inspection object. Is used.

The X-ray source 12 includes an X-ray tube that includes an electron source and an X-ray target irradiated with an electron beam generated from the electron source, and generates X-rays. The imaging plate 13 uses a stimulable fluorescent light emission phenomenon (BaFBr: EU ²⁺ ) that accumulates radiation energy and is subsequently excited by heat or light to emit fluorescence. The film which apply | coated the microcrystal of this. An X-ray image of the inspection object can be obtained by reading the imaging plate 13 that has detected the X-rays transmitted through the inspection object with a reader (not shown). The reader irradiates the surface of the film of the imaging plate 13 with laser light, and reads the light emission amount generated from the film in accordance with the exposure amount of the X-rays, thereby generating an X-ray image to be inspected. . The X-ray source 12 and the imaging plate 13 operate in a state where they are stopped with respect to the laminated rubber bearing 1 with a lead plug. An X-ray image generated by the reader is input to a computer, and distortion correction processing as a correction and synthesis processing are performed as follows by a function obtained by executing image processing software on the computer. The distortion corrected by the distortion correction processing refers to a shape that appears in the X-ray image so as to be different from the shape originally possessed by the member.

  Conventionally, inspection with X-rays irradiated from a stopped X-ray source for inspection objects is for thin objects such as plates and tubes, such as laminated rubber bearings with lead plugs. In the past, a large dimension in the transmission direction has not been targeted. The reason for this is that if the dimension in the transmission direction is large, the attenuation of X-rays is large, so that it is difficult to obtain a clear transmission image, or the diffusion of X-rays is large. It is to grow.

  Further, the lead plug-containing laminated rubber support 1 shown in FIG. 1 is arranged such that the lead plug 4 forms a square apex on a diagonal line in plan view of the lead plug-containing laminated rubber support 1. Therefore, when X-rays are irradiated in a direction perpendicular to the side surface of the laminated rubber bearing 1 with lead plugs, X-rays transmitted through the two lead plugs 4 are detected, and thus any lead plug 4 is damaged. There is a problem that cannot be identified. In addition, since the laminated rubber bearing 1 with lead plugs is arranged between the upper end surface of the pier and the lower flange of the bridge girder, the work area for inspection is narrow and other structures are arranged close to each other. It is often done. Therefore, there is little space for arranging the X-ray source 12 and the imaging plate 13 around the laminated rubber bearing 1 with the lead plug, and the degree of freedom of the arrangement form of the X-ray source 12 and the imaging plate 13 is low.

  Therefore, in the method for inspecting the laminated rubber bearing with metal plug according to the present embodiment, as shown in FIG. 3, the X-ray irradiated from the X-ray source 12 is the laminated rubber bearing 1 with the X-ray center axis Xa being the lead plug. The imaging plate 13 is disposed on a side surface adjacent to the side surface where the X-rays are incident at right angles. In other words, X-rays are detected by the imaging plate 13 arranged to be inclined with respect to the central axis Xa of X-rays emitted from the X-ray source 12. Since the X-ray image obtained in this way includes distortion due to the X-ray characteristics, it is corrected by performing distortion correction processing by computer image processing.

FIG. 4 shows an X-ray image of the lead plug 4 detected by X-rays whose central axis Xa is inclined by an angle (π / 2−θ ₄ ) with respect to the normal of the side surface of the laminated rubber bearing 1 with lead plug. It is a figure which shows the relationship between the damage which has arisen in the actual lead plug 4, and. In FIG. 4, reference numeral 18 denotes an X-ray image acquired by the imaging plate 13 in accordance with the installation position in the width direction of the imaging plate 13 in the plan view of the laminated rubber bearing 1 with a lead plug. The plan view of the laminated rubber bearing 1 with a lead plug corresponds to the X-ray image 18 acquired by the imaging plate 13 and shows damage caused to the lead plug 4. In the X-ray image 18, 44 is an image of the lead plug 4, 45 is an image of the flow damage 15 generated on one side of the lead plug 4, and 46 is a flow generated on the other side of the lead plug 4. It is an image of damage 16. Although the flow damages 15 and 16 generated in the lead plug 4 do not reach the flow protrusion from which the lead protrudes from the side surface of the laminated body 2, the lead plug 4 is deformed. It is falling. In order to accurately specify the deformed form of the lead plug 4, distortion correction processing of the X-ray image 18 is performed as follows.

ここで、Ａは、Ｘ線源１２の焦点である。Ｂは、Ｘ線源１２の焦点から、鉛プラグ入り積層ゴム支承１のＸ線が入射する側面と平行に延ばした線と、検査対象の鉛プラグ４の中心Ｏから上記Ｘ線が入射する側面の法線方向に延ばした線との交点である。また、Ｃは、Ｘ線源１２の焦点から、鉛プラグ入り積層ゴム支承１のＸ線が入射する側面と平行に延ばした線と、イメージングプレート１３が設置された鉛プラグ入り積層ゴム支承１の側面であってＸ線が出射する側面を平行に延ばした線との交点である。また、Ｄは、Ｘ線源１２の焦点Ａから、鉛プラグ入り積層ゴム支承１のＸ線が入射する側面へ法線方向に延ばした線の交点である。また、Ｅは、鉛プラグ入り積層ゴム支承１のＸ線が入射する側面と、イメージングプレート１３が設置された鉛プラグ入り積層ゴム支承１の側面との交点である。また、Ｆは、イメージングプレート１３が設置された鉛プラグ入り積層ゴム支承１の側面において、イメージングプレート１３の一端に相当する点である。また、Ｇは、イメージングプレート１３の検出面の幅方向において、イメージングプレート１３に投射される鉛プラグ４の一方の流動損傷１５の端を示す点である。また、Ｈは、イメージングプレート１３の検出面の幅方向において、鉛プラグ４の一方の側の境界を示す点である。また、Ｉは、イメージングプレート１３の検出面の幅方向において、鉛プラグ４の他方の側の境界を示す点である。また、Ｊは、イメージングプレート１３の検出面の幅方向において、イメージングプレート１３に照射される鉛プラグ４の他方の流動損傷１６の端を示す点である。また、Ｋは、鉛プラグ入り積層ゴム支承１のＸ線が入射する側面が平面視において現れる線と、検査対象の鉛プラグ４の中心Ｏから上記Ｘ線が入射する側面の法線方向に延ばした線との交点である。また、Ｒは、イメージングプレート１３に投射される鉛プラグ４の一方の流動損傷１５の端を通るＸ線と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｓは、イメージングプレート１３に投射される鉛プラグ４の一方の側の境界を通るＸ線と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｔは、一方の流動損傷１５が生じた鉛プラグ４の側面と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｕは、他方の流動損傷１６が生じた鉛プラグ４の側面と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｖは、イメージングプレート１３に投射される鉛プラグ４の他方の側の境界を通るＸ線と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｗは、イメージングプレート１３に投射される鉛プラグ４の他方の流動損傷１６の端を通るＸ線と、鉛プラグ４の中心Ｏを通ってイメージングプレート１３の検出面と平行な線との交点である。また、Ｏは、鉛プラグ４の中心である。また、Ｐは、イメージングプレート１３に投射される鉛プラグ４の他方の側の境界を通るＸ線と、鉛プラグ４の側面との接点である。また、Ｑは、イメージングプレート１３に投射される鉛プラグ４の一方の側の境界を通るＸ線と、鉛プラグ４の側面との接点である。また、ｒは鉛プラグ４の半径である。 First, the distance between the symbols of each point shown in the plan view of FIG. 4 is set as follows.

Here, A is the focal point of the X-ray source 12. B is a line extending from the focal point of the X-ray source 12 in parallel with the side surface on which the X-ray of the laminated rubber bearing 1 with lead plugs is incident, and the side surface on which the X-rays are incident from the center O of the lead plug 4 to be inspected. This is the intersection with the line extending in the normal direction. C is a line extending from the focal point of the X-ray source 12 in parallel with the side surface on which the X-ray of the lead-plug laminated rubber bearing 1 is incident, and the lead-plug laminated rubber bearing 1 on which the imaging plate 13 is installed. It is an intersection with a line which is a side surface and extends in parallel with a side surface from which X-rays are emitted. D is an intersection of lines extending in the normal direction from the focal point A of the X-ray source 12 to the side surface on which the X-rays of the laminated rubber bearing 1 with lead plugs are incident. E is the intersection of the side surface on which the X-ray is incident on the laminated rubber bearing 1 with the lead plug and the side surface of the laminated rubber bearing 1 with the lead plug on which the imaging plate 13 is installed. F is a point corresponding to one end of the imaging plate 13 on the side surface of the laminated rubber bearing 1 with a lead plug on which the imaging plate 13 is installed. G is a point indicating the end of one flow damage 15 of the lead plug 4 projected on the imaging plate 13 in the width direction of the detection surface of the imaging plate 13. H is a point indicating a boundary on one side of the lead plug 4 in the width direction of the detection surface of the imaging plate 13. I is a point indicating the boundary on the other side of the lead plug 4 in the width direction of the detection surface of the imaging plate 13. J is a point indicating the other end of the flow damage 16 of the lead plug 4 irradiated to the imaging plate 13 in the width direction of the detection surface of the imaging plate 13. Further, K is extended in the normal direction of the side surface where the X-ray incident side of the laminated rubber bearing 1 containing the lead plug appears in plan view and the side surface where the X-ray enters from the center O of the lead plug 4 to be inspected. It is an intersection with the line. R is an X-ray passing through the end of one flow damage 15 of the lead plug 4 projected on the imaging plate 13 and a line parallel to the detection surface of the imaging plate 13 through the center O of the lead plug 4. It is an intersection. S is an intersection of an X-ray passing through the boundary on one side of the lead plug 4 projected onto the imaging plate 13 and a line passing through the center O of the lead plug 4 and parallel to the detection surface of the imaging plate 13. is there. T is the intersection of the side surface of the lead plug 4 in which one flow damage 15 has occurred and a line parallel to the detection surface of the imaging plate 13 through the center O of the lead plug 4. U is an intersection of the side surface of the lead plug 4 in which the other flow damage 16 has occurred and a line parallel to the detection surface of the imaging plate 13 through the center O of the lead plug 4. V is an intersection of an X-ray passing through the boundary on the other side of the lead plug 4 projected on the imaging plate 13 and a line parallel to the detection surface of the imaging plate 13 through the center O of the lead plug 4. is there. W is an X-ray passing through the end of the other flow damage 16 of the lead plug 4 projected on the imaging plate 13 and a line parallel to the detection surface of the imaging plate 13 through the center O of the lead plug 4. It is an intersection. O is the center of the lead plug 4. P is a contact point between the X-ray passing through the boundary on the other side of the lead plug 4 projected onto the imaging plate 13 and the side surface of the lead plug 4. Q is a contact point between the X-ray passing through the boundary on one side of the lead plug 4 projected onto the imaging plate 13 and the side surface of the lead plug 4. R is the radius of the lead plug 4.

ここで、

である。また、

である。また、

である。また、

である。 The length L ₁₁ of the image 45 of one flow damage 15 and the length L ₁₂ of the image 46 of the other flow damage 16 in the X-ray image 18 detected by the imaging plate 13 are shown in FIG. Based on the geometric relationship, it is expressed as follows.

here,

It is. Also,

It is. Also,

It is. Also,

It is.

また、他方の流動損傷１６が鉛プラグ４の側面から流動した流動長について、Ｘ線撮影画像１８に投影された流動長から算出した第２流動長Ｌ_１４を、次の式により算出する。

さらに、これらの第１流動長Ｌ_１３及び第２流動長Ｌ_１４は、傾斜方向からの投影により、流動長が過少に評価される傾向にある。そこで、下記のように、流動損傷１５，１６を含めた全幅から鉛プラグ４の幅を差し引くことにより、上記第１及び第２流動長Ｌ_１３，Ｌ_１４よりも高い精度の合計流動長Ｌ_１５を求めることができる。

These, for flow length of one flow damage 15 is flow from the side of the lead plug 4, the first flow length L ₁₃ which is calculated from the flow length projected on the X-ray image 18 is calculated by the following equation.

Further, the second flow length L ₁₄ calculated from the flow length projected on the X-ray image 18 is calculated by the following equation for the flow length of the other flow damage 16 flowing from the side surface of the lead plug 4.

Further, the first flow length L ₁₃ and the second flow length L ₁₄ tend to be underestimated by the projection from the tilt direction. Therefore, the total flow length L _{15 with} higher accuracy than the first and second flow lengths L ₁₃ and L ₁₄ is obtained by subtracting the width of the lead plug 4 from the total width including the flow damages 15 and 16 as described below. Can be requested.

By such a distortion correction process, the inclination angle θ _{4 with} respect to the laminated rubber support 1 with lead plug, the distance between the X-ray source 12 and the imaging plate 13, the laminated rubber support 1 with lead plug and the X-ray source 12. based on the distance and the like between, corrects distorted dimensions of lead plug 4 in the X-ray image can be obtained substantially total flow length L ₁₅ is a flow length of the actual size of the lead plug 4. Incidentally, the first and second flow lengths _{L 13, L 14} may be employed as the flow length.

  The X-ray image 18 acquired by the imaging plate 13 can be corrected by executing the distortion correction processing on a plurality of cross sections in the height direction of the laminated rubber bearing 1 with lead plug.

  In the distortion correction processing, as described above, correction is performed based on the geometric relationship between the X-ray irradiation angle of the X-ray source 12, the X-ray irradiation path, and the constituent parts of the laminated rubber bearing 1 with lead plugs. In addition to the above, the X-ray image is corrected based on the shape inherent to the component part of the laminated rubber bearing 1 with the lead plug. FIG. 5A is an X-ray image showing the side portion of the lead plug 4 before the distortion correction processing as correction, and FIG. 5B shows the side portion of the lead plug 4 after the distortion correction processing as correction. FIG. As shown in FIG. 5A, in the X-ray image before correction, the end of the image of the steel plate 41 of the laminate 2 appears in a tapered shape that becomes narrower as the tip is diffused with the distance from the X-ray source. . Since the steel plate 41 of the laminate 2 is originally formed with a uniform thickness, the distortion of the X-ray image is corrected so that the steel plate 41 has the original shape. Specifically, the predetermined region including the tapered portion is deformed so that the tapered portion of the image of the steel plate 41 in FIG. 5A is parallel. As described above, by correcting the X-ray image so that the shape of the member image in the X-ray image is the original shape, the distortion of the X-ray image can be effectively corrected. . The lead plug 4 can be inspected by the X-ray image thus corrected by correcting the distortion. For example, according to FIG. 5B, it can be seen that the concavo-convex portion 19 is formed on the side surface of the lead plug 44 and damage due to the flow of lead occurs.

  The X-ray image is preferably subjected to a composition correction process after a distortion correction process. In the laminated rubber bearing 1 with lead plugs, since a plurality of steel plates 8 extend in the plane direction in parallel to each other in the laminated body 2, when X-rays enter the side surface of the laminated body 2, the central axis Xa of the X-rays On the other hand, the steel plate 8 at a position away from the stacked body 2 in the height direction shows an image projected obliquely in the height direction in the X-ray image obtained by the imaging plate 13. Therefore, in the method for inspecting a laminated rubber bearing with a metal plug according to the present embodiment, X-ray imaging images are acquired by setting X-ray irradiation positions by the X-ray source 12 at five different positions in the height direction. A portion near the height corresponding to the X-ray central axis Xa is extracted from each of the acquired five X-ray images, and one X-ray image is created by combining the extracted portions.

  FIGS. 6A to 6E are X-ray images used for performing the synthesis process. 6A is an X-ray image in which the center axis Xa of the X-ray is located at the upper part of the stacked body 2, and FIG. 6B is an X-ray image in which the center axis Xa of the X-ray is positioned below the stack 2 in FIG. 6C is an X-ray image in which the central axis Xa of the X-ray is located below the stack 2 in FIG. 6B, and FIG. 6D is the X-ray central axis Xa in the stack 2. 6C is an X-ray image that is located below FIG. 6C, and FIG. 6E is an X-ray image in which the central axis Xa of the X-ray is located below FIG. From each of these X-ray images, a portion having a height corresponding to the X-ray central axis Xa is extracted over a predetermined height, and the extracted portions are sequentially arranged in the height direction. Such an X-ray image is obtained. 6A to 6E, portions with less distortion in the height direction are extracted and synthesized in the height direction to create the X-ray image of FIG. 6F. FIG. 6G is a cross-sectional view showing a state in which the laminated rubber support 1 with a lead plug obtained by irradiating X-rays to acquire an X-ray image is cut. As is clear from a comparison between FIG. 6F and FIG. 6G, an accurate X-ray image showing the inside of the laminated body 2 of the laminated rubber bearing 1 with a lead plug can be obtained by performing the synthesis process. For example, the flow part 20 of the lead plug 4 in FIG. 6G clearly appears as the flow part 46 of the lead plug 44 in FIG. 6F. As described above, the composition processing can obtain a clear X-ray image of the laminate 2 with less distortion by combining X-ray images acquired by irradiating X-rays from different heights. Therefore, it is possible to accurately grasp the shape of the lead plug 4 and perform an accurate inspection. The X-ray image to be synthesized may be obtained by irradiating the laminated body 2 with X-rays from different positions in the height direction, or may be obtained by irradiating X-rays with different incident angles.

  Next, the attenuation performance remaining on the lead plug 4 is evaluated based on the X-ray image obtained by performing the distortion correction processing and the synthesis processing as described above. FIG. 7 is a graph showing a decrease in attenuation performance with respect to a decrease in the volume of the lead plug 4. In FIG. 7, the horizontal axis represents the ratio of the volume of the lead plug after the deformation to the volume of the lead plug before the deformation, and the vertical axis represents the lead plug after the deformation with respect to the damping performance of the lead plug before the deformation. Is the ratio of the damping performance of As shown in FIG. 7, there is a correlation between the attenuation performance of the lead plug and the volume. Therefore, the attenuation performance of the lead plug 4 can be specified based on the change in volume accompanying the deformation of the lead plug 4. Specifically, the volume of the lead plug 4 after deformation is obtained from an X-ray image as shown in FIG. 6F, and the value of the ratio of the volume after deformation is calculated from the initial volume of manufacture of the lead plug 4. . In FIG. 6F, the lead plug 4 photographed from one direction appears. By using a plurality of X-ray images obtained by photographing the lead plug 4 from different directions, the flow protrusion amount of the lead plug 4 is shown. Is accurately grasped, and the volume of the lead plug 4 after the deformation can be accurately obtained. In particular, if an X-ray image of the entire circumference of the lead plug 4 can be used, the volume after the deformation of the lead plug 4 can be obtained more accurately. The ratio of the volume ratio of the lead plug 4 to the initial stage of manufacture is compared with the graph of FIG. 7 to specify the ratio of the lead plug 4 to the initial damping performance. The damping performance of the lead plug 4 can be specified based on the ratio thus specified, and the performance remaining on the laminated rubber bearing 1 with the lead plug can be evaluated.

  Thus, according to the inspection method of the laminated rubber bearing with a metal plug according to the present embodiment, the laminated rubber bearing 1 with a lead plug is installed in the original position where the laminated rubber bearing 1 with a lead plug is not destroyed without breaking. The deformation of the lead plug 4 can be detected. Further, the laminated rubber bearing 1 with lead plugs installed between the bridge pier and the bridge girder has the X-ray irradiation direction of the X-ray source 12 with respect to the imaging plate 13 due to a small space for inspection. Even if the inclination is inclined, the lead plug 4 can be accurately inspected by performing distortion correction processing and synthesis processing on the X-ray image. Further, by utilizing the correlation of the attenuation performance with respect to the volume of the lead plug 4, the amount of decrease in the attenuation performance of the lead plug 4 can be obtained from the amount of decrease in the volume of the lead plug 4 obtained from the X-ray image. As a result, the performance remaining on the laminated rubber bearing 1 with lead plug can be evaluated non-destructively.

  In the above embodiment, an X-ray image with less distortion is formed by combining a plurality of X-ray images. When these X-ray images are imaged, the laminated rubber support 1 with a lead plug is connected to the X-ray image. It is preferable to add a mark appearing in the line image. A plurality of X-ray images captured in this way can be easily combined by using the mark image in the X-ray image as a reference.

  In the above-described embodiment, binarization of the X-ray image may be performed prior to the distortion correction process and the synthesis process. Since the laminated rubber bearing 1 with a lead plug has a long distance through which X-rays pass, attenuation tends to occur. In particular, since the distance passing through the plate rubber 7 and the steel plate 8 constituting the laminate 2 is longer than the distance passing through the lead plug 4, the image of the lead plug 4 adjacent to the plate rubber 7 or the steel plate 8 is unclear. It is easy to become. Here, by binarizing the X-ray image, the image of the lead plug 4 can be made clear, and as a result, an accurate inspection of the lead plug 4 can be performed. Further, the amount of X-ray transmission with respect to the members constituting the laminated rubber bearing 1 with a metal plug is relatively large for the plate-like rubber 7 of the laminated body 2, while being relatively small for the steel plate 8 and the lead plug 4. Therefore, by performing the binarization processing of the X-ray image, it is possible to clearly distinguish the plate rubber 7 of the laminated body 2 from the steel plate 8 and the lead plug 4. Thus, in order to sharpen the X-ray image of the laminated rubber bearing 1 with a metal plug, the binarization process is effective due to the difference in X-ray permeability of the constituent members.

  Moreover, in the said embodiment, although the example which test | inspects the laminated rubber bearing 1 with a lead plug which has the lead plug 4 as a laminated rubber bearing with a metal plug was described, the metal plug formed, for example with other materials, such as tin, is described. It may be a laminated rubber bearing with a metal plug. The inspection method and the performance determination method of the present invention are applicable to laminated rubber bearings with metal plugs having various metal plugs having a damper function.

  In addition, the inspection method of the present invention is not limited to laminated rubber bearings with metal plugs that are assumed to be damaged due to earthquakes or aging, but to determine the current performance of laminated rubber bearings with metal plugs. Applicable. For example, even if the elapsed time after installation is relatively short, if there is a doubt about the performance of the laminated rubber bearing with metal plug, the laminated rubber bearing with metal plug can be obtained by applying the inspection method of the present invention. The current performance can be determined.

  In the said embodiment, although the case where this invention was applied to the laminated rubber bearing 1 with a lead plug installed in the road bridge was demonstrated, it is not restricted to a road bridge, but various railway bridges, humanitarian bridges, pipeline bridges, etc. The present invention can be applied to bridge support. Moreover, this invention is applicable not only to the support of a bridge but to the support as a vibration isolator installed in the foundation of buildings, such as a building. Moreover, it is applicable also to the support as a vibration isolator installed in the structure of a plant.

1 Laminated rubber bearing with lead plug 2 Laminated body 3 Connection body 4 Lead plug 5 Cover rubber 6
7 Plate rubber 8 Steel plate 12 X-ray source 13 Imaging plate 15, 16 Flow damage 18 X-ray image

Claims (7)

A laminated body in which a plurality of plate-like rubbers and steel plates are alternately laminated, a connection body disposed on one surface and the other surface of the laminated body and connected to a structure, and the laminate and the connection body A method for inspecting a laminated rubber bearing with a metal plug comprising a metal plug having a damper function extending through the laminating method of the plate rubber and the steel plate,
In the original position where the laminated rubber bearing with the metal plug is installed, the laminated body is irradiated with X-rays to obtain an X-ray image, and based on the contour shape of the image of the metal plug in the X-ray image. Inspection method for laminated rubber bearing with metal plug, characterized by performing inspection. In the inspection method of the laminated rubber bearing with a metal plug according to claim 1,
A method for inspecting a laminated rubber bearing with a metal plug, wherein the X-ray image is corrected in accordance with an X-ray incident position and / or incident angle with respect to the laminate. In the inspection method of the laminated rubber bearing with a metal plug according to claim 1,
Based on the position of the mark previously set on the laminated body and the position of the image of the mark in the X-ray image, the imaging position of the X-ray image on the laminated rubber bearing with the metal plug is specified. An inspection method for laminated rubber bearings with metal plugs. In the inspection method of the laminated rubber bearing with a metal plug according to claim 1,
A plurality of X-ray images are created by setting different X-ray incident positions and / or incident angles with respect to the laminate, and the plurality of X-ray images are combined to inspect X for inspection. A method for inspecting a laminated rubber bearing with a metal plug, characterized by producing a line image. In the inspection method of the laminated rubber bearing with a metal plug according to claim 1,
A method for inspecting a laminated rubber bearing with a metal plug, wherein the X-ray image is binarized. Estimating a volume of the metal plug from an image of the metal plug in the X-ray image obtained by the inspection method of the laminated rubber bearing with a metal plug according to claim 1;
Evaluating the damping performance of the laminate in light of a correlation model indicating the correlation between the estimated volume of the metal plug and the damping performance obtained in advance. To judge the performance of laminated rubber bearings with metal plugs. Estimating a crack amount of the metal plug from an image of the metal plug in the X-ray image obtained by the inspection method of the laminated rubber bearing with a metal plug according to claim 1;
A step of evaluating the damping performance of the laminate in light of a correlation model showing the correlation between the estimated amount of cracking of the metal plug and the amount of decrease in damping performance. A method for judging the performance of a laminated rubber bearing with a metal plug, comprising:

Images