JP2011149858A - Non-destructive measurement fixture, device for measuring concrete covering thickness using the same, and method for measuring concrete covering thickness in sc pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-destructive measurement fixture capable of simply and accurately performing non-destructive measurement from an internal wall side concerning a small inside diameter and the depth part of an existing long hollow tube, and to provide a device for measuring a concrete covering thickness using the fixture, and a method for measuring the concrete covering thickness in an SC pile with the measuring device. <P>SOLUTION: The device II for measuring the concrete covering thickness to measure the covering thickness X is installed in a hollow part 104 of the SC pile 100. The device II for measuring the concrete covering thickness includes the non-destructive measurement fixture and a reinforcing bar probe. A rotating rod 200 is arranged in a neighborhood of the center of a cross section of the hollow part 104, a measuring part is connected to the tip (depth part of the SC pile) of the rotating rod 200, a centerizer is connected to a neighborhood thereof, an operation is connected to an opening of the end face of the SC pile 100, and the non-destructive measurement fixture is constituted of them. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a non-destructive measuring device that is installed in a hollow portion of a hollow pile so that measurement can be performed stably and efficiently when measuring the inner wall surface and the inside of the pile body from the inner wall side of the hollow pile such as SC pile. Nondestructive measurement jig for supporting and operating the detector, a concrete covering thickness measuring apparatus in which a probe of a reinforcing bar probe is installed at the detector mounting portion of the nondestructive measuring jig, and the concrete covering thickness measuring apparatus It is related with the concrete covering thickness measuring method in SC pile.

  Conventionally, non-destructive measurement techniques using ultrasonic waves, electromagnetic waves, elastic waves, magnetism, electromagnetic induction, etc. are widely known in order to grasp the deterioration status, bar arrangement status, construction status, etc. of concrete structures and concrete products.

  For example, Patent Documents 1 and 2 disclose a technique for measuring the cover thickness and the bar arrangement position of a reinforcing bar in a concrete structure by an electromagnetic induction method. The technique of Patent Document 1 is to measure the cover thickness of a reinforcing bar by combining an electromagnetic exploration method using electromagnetic waves and a magnetic exploration method using electromagnetic induction. The technique of Patent Document 2 uses a coil-type sensor using an electromagnetic induction method to measure the reinforcing bar. It is to check the presence or absence of.

  Under such circumstances, piles used for pile foundation construction are required to have high strength and high durability as the concrete structure grows larger and taller, and it is made of reinforced concrete with reinforcing steel bars and PC steel. Things have been developed.

  Along with this, for quality control, it has become necessary to check whether the reinforcing steel bars and PC steel materials are arranged as designed, or whether they are misaligned during the manufacturing process. Destructive measurements are also being considered.

  On the other hand, various jigs (auxiliary tools) for efficiently performing various operations such as non-destructive measurement and cutting in a long hollow portion such as a pile hole or a concrete pipe are also known. For example, Patent Document 3 discloses an apparatus (jig) for measuring a pile hole diameter in a cast-in-place pile with a displacement meter. Patent Documents 4 and 5 disclose jigs used when cutting a concrete pipe from the inner surface. Further, Patent Document 6 discloses a robot (jig) used when investigating the inside of a pipe tube with a sensor.

JP 2003-315004 A JP 2007-178365 A Japanese Patent Laid-Open No. 04-86515 Japanese Patent Laid-Open No. 06-210625 JP 2000-280232 A Japanese Patent Laid-Open No. 09-254781

  As described above, there is a need for nondestructive measurement in piles used for pile foundation construction, but depending on the type of pile and the size of the pile, it cannot be measured effectively and effectively.

  For example, when measuring the concrete covering thickness of a hollow ready-made concrete pile with reinforcing steel bars in the pile body, it can be easily measured by installing a probe of a reinforcing bar probe on the outer wall surface if it is a general concrete pile However, since it is difficult to measure the steel plate having the outer shell steel plate such as SC pile from the outside, the measurement is performed by installing the probe on the inner wall.

  In this case, if the inner diameter of the pile is large, people can enter the hollow part and measure at various locations, but if the inner diameter of the pile is small, humans cannot enter it, so measure within the reach of the pile end or the sample The pile is cut and the concrete covering thickness at the cross section is measured.

  As described above, various jigs (auxiliary tools) for efficiently performing various operations such as nondestructive measurement and cutting work in a long hollow portion such as a pile hole or a concrete pipe are also known. When nondestructive measurement is performed from the inner wall side of the hollow pile, there is still no simple nondestructive measurement jig that enables nondestructive measurement at a depth of 1 m or more from the end of the pile.

  The present invention has been made to improve the above situation, and the purpose of the present invention is as follows: (1) Simple and capable of nondestructive measurement at a depth of 1 m or more from the pile end. Providing a nondestructive measuring jig, (2) providing a concrete covering thickness measuring device in which a probe (detector) of a reinforcing bar probe is attached to the nondestructive measuring jig, (3) the concrete covering thickness measuring apparatus Is to provide a concrete covering thickness measurement method for SC piles.

  As a result of intensive studies to achieve the above object, the present inventors attached a measuring device equipped with a detector for nondestructive measurement to a rotating rod similar to the rod used in pile construction, and rotated the rotating rod at a predetermined depth. It has been found that if the measuring device is rotated in the circumferential direction by utilizing the rotation of the rod, the measurement can be performed at an arbitrary place that cannot be reached by human hands, and the present invention has been completed. The contents are described in claims 1 to 7.

  The invention according to claim 1 of the present application is “a nondestructive measurement jig installed in a hollow portion of a hollow pile, and a nondestructive measurement detector installed in the vicinity of the inner wall of the hollow pile is fixed. A measuring part for operating, an operating part for moving the detector in the circumferential direction of the inner wall, and a rotational drive shaft of the detector, and the measuring part and the operating part are arranged in the radial direction on the inner wall surface of the hollow pile A rotating rod disposed in the direction of the pile axis in the vicinity of the cross-sectional center of the hollow pile, and a center riser part for fixing the rotating rod near the cross-sectional center in the vicinity of the measurement point. "Non-destructive measuring jig".

  Although the present invention is intended for hollow piles, it can also be used for concrete pipes such as fume pipes similar to the hollow piles, propulsion pipes, and other various long pipes.

  The nondestructive measuring jig of the present invention moves the detector for fixing a nondestructive measuring detector installed close to the inner wall of the hollow pile and the detector in the circumferential direction of the inner wall. And an operating part for connecting to a rotating rod arranged in the axial direction of the pile in the vicinity of the cross-sectional center of the hollow pile in order to support them radially on the inner wall surface of the hollow pile, and the rotating rod is measured by the center riser part It is fixed near the center of the cross section of the hollow pile near the location.

  The operation unit is provided on the end surface, and the measurement unit (detector) is operated by the operator. For example, one rotating rod can be measured at an arbitrary depth by connecting a plurality of rods by rod coupling with a rod made of white alumite having a length of about 40 mmφ and a length of about 1000 mm.

  The rotating rod is fixed near the cross-sectional center of the hollow pile by the center riser portion in the vicinity of the measurement location (measurement portion). As a result, the measurement unit (detector) can be stably moved in the circumferential direction, so that stable and accurate measurement can be performed.

  As described above, the nondestructive measurement jig according to the present invention has a simple structure in which a rotating rod is a main shaft and a measurement unit, an operation unit, and a center riser unit that stabilizes the measurement unit are connected to the jig. It can be easily installed inside, and nondestructive measurement from the inner wall side can be easily performed.

  The detector is not particularly limited as long as it can nondestructively measure the inner wall surface and the inside of various pipes such as hollow piles, and any inspection device such as an ultrasonic inspection and a radiation inspection can be used.

  The invention according to claim 2 of the present application is as follows: "The measurement unit is connected to the rotating rod at a right angle and has one measurement unit support leg with a spring extending in the radial direction of the hollow pile. The tip is provided with a mounting portion for mounting the detector and a wheel for smoothly moving the detector in the circumferential direction of the inner wall, and is supported by a balancer support leg in the opposite direction to the rotating rod. The nondestructive measurement jig according to claim 1, wherein a fixed balancer is provided.

  The measurement unit is installed at a predetermined depth to be measured. The measuring part has one spring-supported measuring part supporting leg that is connected at right angles to the rotating rod and extends in the radial direction of the hollow pile. And a wheel for smoothly moving in the circumferential direction.

  By adopting such a structure, even if there is some unevenness on the inner wall surface of the hollow pile, the position of the detector is stabilized and the movement in the circumferential direction is smoothed, and stable measurement can be performed. In addition, a balancer that is supported and fixed to the balancer support leg is provided in the direction opposite to the detector with respect to the rotating rod, so that the detector can be placed on the inner wall surface of the hollow pile at any position in the circumferential direction. On the other hand, it can be held at a fixed position.

  The invention according to claim 3 of the present application is as follows: “The center riser portion is connected to the rotating rod via a bearing, and the center riser is attached to the center riser and has a wheel at the tip and is different from a hollow pile. 3. The non-supporting leg according to claim 1, further comprising 2 to 4 center riser support legs for fixing the rotating rod near the center of the cross section by stretching the inner wall in the radial direction of the cross section. Destruction measurement jig ".

  The center riser portion is for fixing the rotating rod near the center of the cross section so that stable measurement can be performed by the measurement portion, and is installed in the vicinity of the measurement location (measurement portion). It has 2 to 4 leg center riser support legs with wheels at the tip, and the rotating rod is fixed in the vicinity of the center of the cross section by stretching it on the inner walls of different 2 to 4 cross section radial directions of the hollow pile.

  The center riser portion is connected to the rotating rod through a bearing. By adopting such a structure, even if the rotating rod rotates, the center riser portion can continue to be fixed near the center of the cross section without moving in synchronization.

  The invention according to claim 4 of the present application states that “the operation unit displays a rotation handle for rotating the rotation rod via a gear, a rotation angle of the rotation rod, and / or a rotation angle of the detector. Rotating angle plate capable of being connected to the rotating rod at right angles to support the gear, the rotating handle, and the rotating angle plate. The jig for nondestructive measurement according to any one of claims 1 to 3, further comprising 2 to 4 operation unit support legs which are installed and fixed to the base.

  The operation part is installed on the end face of the hollow pile, and the operation part support leg of 2 to 4 legs is fixed to the hollow pile with a fixing clamp in the radial direction of 2 to 4 different cross sections of the hollow pile at the opening part of the hollow pile. Installed. An operation handle (rotation handle) and an operation panel (rotation angle plate, etc.) are provided on the front surface of the opening.

  By adopting such a structure, an operator operates at the opening entrance of the hollow pile to easily move and measure the detector provided in the measurement section to an arbitrary measurement position in the pile circumferential direction. Can do.

  The invention according to claim 5 of the present application is “a concrete covering thickness measuring device for a ready-made hollow pipe such as a ready-made hollow pile in which any one or more of main reinforcing bars, PC steel bars, and PC steel wires are arranged in a concrete pile main body. A concrete covering thickness measuring device using the nondestructive measuring jig according to any one of claims 1 to 4, wherein a probe of a reinforcing bar probe is installed as a detector in the measuring unit. It is a concrete covering thickness measuring device characterized by

  A concrete covering thickness measuring device is completed by installing a probe of a reinforcing bar probe as a detector at the detector mounting portion of the measuring portion of the nondestructive measuring jig. For ready-made hollow pipes such as concrete-made hollow piles with reinforcing bars, the bar arrangement and the concrete covering thickness are important in terms of quality. Measurement from the inner wall side is easy.

  The invention according to claim 6 of the present application is “the concrete covering thickness measuring device according to claim 5, wherein the ready-made hollow pile is an SC pile”.

  Since the SC pile has a shell steel pipe, it is difficult to measure the concrete cover thickness from the outside. In addition, a pile with a large inner diameter allows a person to enter the hollow and measure the covering thickness from the inner wall side.

  Since it can measure simply if the measuring apparatus of this invention is used, it is suitable for measuring the concrete covering thickness of such SC pile.

  The invention according to claim 7 of the present application is “a concrete covering thickness measurement method in an SC pile that measures the concrete covering thickness of the main reinforcement in the SC pile in which the main reinforcement is arranged using the concrete covering thickness measuring device according to claim 5. The center portion of the SC pile hollow portion adjusted in advance so that the length of the support portion of the measuring portion and the center riser portion supporting leg of the electromagnetic induction type reinforcing bar probe previously attached to the attachment portion can be supported. It is positioned so that it can be installed on the rotating rod, attached to the rotating rod, the operating part is attached to the end of the rotating rod away from the measuring part, the rotating rod is inserted into the SC pile hollow part from the measuring part side, and the operating The part is fixed to the opening of the SC pile end, the probe is rotated in the circumferential direction by rotating the rotating rod with the rotary handle of the operation unit, and the circumferential direction Measuring the distance from the probe at a constant position to the main reinforcement surface of SC piles within a concrete thickness measuring method suffer "in SC piles, characterized in that to determine the concrete wearing thickness at the measurement position.

  In the present invention, an electromagnetic induction rebar probe is used as a non-destructive measuring device for concrete covering thickness. There are various non-destructive measurement methods for concrete covering thickness, such as the electromagnetic induction method, the underground radar method, and the ultrasonic method, but in the measurement using the nondestructive measurement jig of the present invention, the electromagnetic induction method is used. It turned out to be preferable.

  As an electromagnetic induction type rebar exploration device, for example, there is Profometer 5 (Geo Five). Set the universal probe at the detector mounting location, connect to the display device with the probe cable, and measure.

  In the present invention, a measurement jig is assembled and measured at the time of measurement. Prepare the required length of the rotating rod, attach the measuring unit with the probe of the rebar probe to the position of the rotating rod corresponding to the depth of the measurement location, and place the center riser at the position near the rotating rod Insert into the hollow part of the mounting SC pile to a predetermined depth.

  After that, if the operation part is attached to the end face of the opening, the nondestructive measuring device can be easily set. Then, if the probe is rotated in the circumferential direction of the pile by a rotary handle of the operation section and measured, the concrete covering thickness state at that depth can be known. If the same thing is done by changing the depth appropriately, the overall situation of the concrete covering thickness of the SC pile can be understood.

  As described above, if the measurement method of the present invention is used, the concrete covering thickness situation in the SC pile, which has conventionally been difficult to perform nondestructive measurement, can be easily and accurately measured.

  By using the nondestructive measuring jig of the present invention, it is easy and accurate even in the inner part of a long-sized hollow tube having a small inner diameter where a person cannot enter or a human hand does not reach the inner part. Nondestructive measurement can be performed from the inner wall side.

  Moreover, if the concrete covering thickness measuring apparatus of the present invention is used, the concrete covering thickness can be measured nondestructively even with an SC pile that has been difficult to measure without breaking.

  Moreover, if the concrete covering thickness measuring method in the SC pile of the present invention is used, it is possible to easily and accurately grasp the SC pile in which the entire concrete covering thickness is difficult to grasp.

It is a schematic diagram of the jig | tool I for nondestructive measurement of this invention, (a) is the front view of the state to lay down, (b) is a figure which shows an operation part from the left side surface. 3 is a detailed view of a measurement unit C. FIG. It is detail drawing of the center riser part B, (a) is a front view of the main part, (b) is a side view of the main part. It is detail drawing of the operation part A, (a) is a front view of the main part, (b) is a left view of the main part. It is the schematic which shows the condition which installed the concrete covering thickness measuring apparatus using the jig | tool for nondestructive measurement of this invention in SC pile, (a) is a front view of the main part, (b) is the right side of the main part. FIG.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings and the like. In addition, what is described here is an example and this invention is not limited to this.

A. FIG. 1 is a schematic diagram of a nondestructive measurement jig I according to the present invention. (A) is a front view, (b) is a figure which shows an operation part from the left side.

  As shown in FIG. 1 (a), the nondestructive measurement jig of the present invention is obtained by attaching an operation part A, a center riser part B, and a measurement part C to a rotating rod 1.

  The operating portion is attached to the rotating rod 1 by a rod coupling 2-1. The measuring unit C is provided with a detector mounting part 3 for installing a detector for nondestructive measurement. Further, as shown in the right part of the broken line, two rotating rods 1 are connected by the rod coupling 2-2 so that the positions of the center riser part and the measurement part are more centered on the center riser part B ′ and the measurement part C ′. Can be changed to the position.

  As shown in FIG. 1 (b), the operation part A is provided with an operation part support leg 4 extending in three directions, and the operation part A is fixed to the end opening of the ready-made hollow tube. Fixed to the opening. In addition, the operation unit A is provided with an operation panel 5 for rotating the detector attached to the detector attachment unit 3 of the measurement unit C in the circumferential direction by rotating the rotating rod 1.

  FIG. 2 is a detailed view of the measurement unit C.

  A measuring unit fixing frame 10 for connecting to the rotating rod 1 is provided near the center, and measuring unit support legs 20 are provided at right angles thereto. And the detector attachment part 30 for attaching the detector for nondestructive measurement is provided in the front-end | tip.

  The measurement unit support leg 20 includes a measurement unit arm telescopic leg 21 and a measurement unit arm extension leg 22. The measuring unit arm extension leg 22 is used to adjust the length of the measuring unit support leg 20 and is used as required depending on the inner diameter of the ready-made hollow tube.

  A spring 23 is built in the measuring unit arm extendable leg 21 so that the measuring unit arm extendable leg 21 can expand and contract. This is because even if the inner wall surface of the ready-made hollow tube is uneven or the hollow tube is not a perfect circle, the detector can be moved along the inner wall peripheral surface by absorbing the variation in the spring 23. This is because the measurement can be performed smoothly and the inner wall surface and the detector can be measured at a certain distance or in contact with each other as much as possible.

  The detector mounting portion 30 is provided with a joint block 32 for connecting to the measuring unit support leg 20 on the base plate 31, and the detector plate 30 is provided on the opposite side of the base plate 31 for housing the detector via the spacer plate 34. There is a protective case 35. Further, a wheel 33 is provided to contact the inner wall surface of the ready-made hollow tube and smoothly move the detector along the inner wall circumferential surface.

  The wheel 33 is always in contact with the inner wall surface by the spring 23. The detector is structured to float about several millimeters from the inner wall surface by the front and rear wheels 33 so that stable measurement can be performed even if the inner wall surface has some irregularities.

  A balancer support leg 40 is provided on the opposite side of the measurement part support leg 20 with the measurement part fixing frame 10 interposed therebetween, and a balancer 41 is attached near the tip. The balancer 41 balances with the weight of the detector mounting portion 30, and the position of the detector is kept constant with respect to the inner wall surface at any position on the inner wall peripheral surface, so that stable measurement can be performed.

  3A and 3B are detailed views of the center riser portion B, where FIG. 3A shows the main part in the front view, and FIG. 3B shows the main part in the side view.

  To perform stable measurement by smoothly moving the detector in the circumferential direction of the inner wall at a predetermined depth position, the rotating rod of the measurement unit needs to be arranged near the cross-sectional center of the ready-made hollow tube. By installing the riser part in the vicinity of the measuring part and fixing the rotating rod in the center riser part near the center of the cross section, the rotating rod of the measuring part is also arranged near the center of the cross section, so that stable measurement is possible.

  As shown in FIG. 3A, a center riser portion fixing frame 50 for connecting to the rotating rod is provided at the center of the center riser portion B, and is fixed by a fixing ring 51.

  A center riser 60 for supporting the center riser support leg 70 at a right angle to the center riser fixing frame 50 is provided, the center riser support leg 70 is attached to the end thereof, and a wheel 80 is provided at the tip. The center riser portion fixing frame 50 and the center riser 60 are connected via a bearing 61 attached by a bearing fixing nut 62.

  With this structure, even if the rotating rod rotates, the center riser does not rotate and the center riser portion B does not move.

  The center riser leg 70 includes a center riser telescopic leg 71 and a center riser leg 72. These legs advance and retract in the radial direction of the ready-made hollow tube so that the length of the center riser support leg 70 can be adjusted. A wheel 80 is provided at the tip, for the purpose of installing the center riser portion B in a ready-made hollow tube and supporting ready-made hollow tubes of various inner diameters.

  FIG. 3 (a) shows only one center riser support leg 70, but in this embodiment, three legs are provided in three directions of 120 degrees as shown in FIG. 3 (b). . By fixing these three legs to the inner wall of the ready-made hollow tube, the rotating rod inserted into the center riser portion fixing frame is supported and fixed near the cross-sectional center of the ready-made hollow tube.

  4A and 4B are detailed views of the operation unit A. FIG. 4A shows a main part in the front view, and FIG. 4B shows a main part in the left side view.

  As shown in FIG. 4 (a), the operation unit A rotates the rotating rod to move the detector in the measurement unit C in the circumferential direction of the ready-made hollow tube to change the measurement position. It is provided in the end face opening.

  The operation unit A is provided with an operation panel 90 and is attached to the operation unit support leg 91.

  As shown in FIG. 4B, the operation portion support legs 91 are provided in three directions and attached to the end surface opening of the ready-made hollow tube by fixing clamps 92. The operation portion support leg 91 is connected to the rotating rod 94 via a bearing 93.

  With such a structure, even if the rotary rod 94 rotates, the operating portion A is held because the rotational force is not transmitted to the operating portion support leg 91.

  The operation part A is provided with a rotary handle 95 for rotating the rotary rod 94. When an operator rotates the rotary bundle 95, the input gear 96-1, the intermediate gear 96-2, the output gear 96-3, etc. The rotating rod 94 rotates through the gear. Further, a rotation angle plate 97 for displaying the rotation angle, rotation amount, detector rotation angle, rotation position and the like of the rotation rod 94 is provided, and is displayed by the circular protractor 98 and the indicator needle 99.

  FIG. 5 is a schematic diagram showing a situation in which a concrete covering thickness measuring device using the nondestructive measuring jig of the present invention is installed in an SC pile, and (a) shows the main part in the front view, (b ) Shows the main part in the right side view.

  As shown in FIG. 5A, the hollow SC pile 100 has a main bar 102 disposed in a concrete 101 and has an outer iron plate 103. And in the hollow part 104, the concrete covering thickness measuring apparatus II of this invention is installed in order to measure the covering thickness X.

  The dimensions of the SC pile 100 are, for example, an outer diameter of 700 to 1000 mm, an inner diameter of 400 to 740 mm, and a wall thickness of 130 to 150 mm.

  The concrete covering thickness measuring apparatus II includes the nondestructive measuring jig and the reinforcing bar probe of the present invention.

  Near the center of the cross section of the hollow portion 104, two rotating rods 200 having a length of 1000 mm connected by the rod coupling 201 are arranged, and at the tip of the rotating rod 200 (the inner portion of the SC pile is about 2000 mm) The measurement part C is connected, the center riser part B is connected in the vicinity thereof, and the operation part A is connected to the end face opening of the SC pile 100, and these constitute a nondestructive measurement jig.

  The measuring unit C is supported by a measuring unit support leg 300, and a probe 301 of a reinforcing bar probe as a detector is attached to the tip of the measuring unit C. The probe 301 of the reinforcing bar probe is connected to an external reinforcing bar probe display device 305 by a probe cable 304.

  A balancer support leg 302 stands on the opposite side, and a balancer 303 is attached to the tip thereof.

  The rotating rod 200 is supported and fixed to the inner wall 105 of the SC pile by a center riser support leg 400 so that the measuring rod C is always located near the center of the cross section. As shown in FIG. 5 (b), here, the two center riser portion support legs 400 are supported and fixed.

  The operation part A is fixed by fixing the operation part support leg 500 to the SC pile 100 with the fixing clamp 501 at the end face opening of the SC pile 100. Here, as shown in FIG.5 (b), the operation part support leg is fixed to 3 directions with 3 legs.

  A rotary handle 502 is provided on the front surface of the operation unit A. By rotating the rotary rod 200, the probe 301 of the reinforcing bar probe of the measurement unit C rotates in the circumferential direction along the inner wall 105 of the SC pile.

  At this time, the center riser portion B does not rotate due to the action of the bearing and continues to fix the rotating rod 200 at a predetermined position. By rotating the probe 301 of the reinforcing bar probe to an arbitrary position and measuring the covering thickness X at each position, the bar arrangement status of the main bar 102 at that depth can be determined.

  If the measurement position C is changed in the same manner by changing the mounting position of the measuring rod C on the rotating rod 200, data in the circumferential direction and the pile axis direction can be obtained, so that the overall bar arrangement of the main bars 102 in the SC pile 100 can be grasped. .

  In addition, if a scale is provided in the rotating rod 200 with respect to the pile axis direction, the measurement position can be easily grasped. The position in the pile circumferential direction can be easily grasped by providing a rotation angle plate 503 indicating the rotation angle of the rotation rod 200 on the operation panel 504 on the front surface of the operation unit A. Therefore, it can be known at which measurement position the measurement data is data.

  Next, an outline of the procedure of the method of measuring the concrete covering thickness in the SC pile of the present invention, which is measured by installing a concrete covering thickness measuring apparatus as shown in FIG.

[Measurement method of concrete covering thickness in SC pile]
(1) Prior confirmation a. Visually check the inside of the SC pile and confirm that there are no irregularities that would hinder measurement.
b. Check the inner diameter, outer diameter, and measurement position (measurement depth) of the SC pile.

(2) Installation of concrete covering thickness measuring device a. Two rotating rods with a length of 1 m are connected by rod coupling.
b. Fix the probe of the rebar probe to the measuring part with a protective angle.
c. Adjust the length of the measuring unit support leg to the inner diameter of the SC pile and attach the measuring unit to the measuring depth of the rotating rod.
d. A probe cable connecting a probe of a reinforcing bar probe (manufactured by Geo-Five Inc .; electromagnetic induction type) and a display device (measuring instrument) is fixed to a rotating rod.

e. Adjust the length of the center riser support leg according to the inner diameter of the SC pile, and attach the center riser part to half the measurement depth.
f. Attach the operation unit to the rotating rod.
g. The rotating rod to which the measurement unit, the center riser unit, and the operation unit are attached is inserted to a predetermined depth of the SC pile hollow portion.
h. The operation part support leg is fixed to the end face opening of the SC pile with a fixing clamp, and a rotary handle, indicator needle, circular protractor, etc. are attached to the operation panel to complete the installation of the operation part.

(3) Trial run a. While observing the circular protractor of the rotating angle plate, rotate the measuring part once in the circumferential direction with the rotary handle, and then rotate it in the opposite direction to confirm that the axis of the rotating rod can rotate smoothly without brilliance.

(4) Reinforcement probe operation check a. Fix the measurement part to a position where the position directly below the SC pile is the measurement position.
b. Turn on the power of the display device (measuring instrument), slowly rotate the measuring unit by about 45 degrees, and check whether the buzzer sound of the display device (measuring instrument) sounds several times during this time. If the buzzer sounds, it means that the SC pile rebar is detected and the rebar probe is operating normally.

(5) Measurement a. Fix the measurement part to a position where the position directly below the SC pile is the measurement position.
b. Slowly rotate the measurement unit (rebar probe probe) to the right, stop the rotation when the buzzer sounds, press the measurement button on the display device (measuring instrument), and display the measured value and rotation angle plate Enter the angle, measurement depth, etc. on the data sheet.
c. Subsequently, the same operation is performed by rotating it in the right direction, and measurement is performed until it rotates once. In addition, if the measurement by the rotation in the right direction is completed as necessary, the measurement is similarly performed in the rotation in the left direction.
d. If necessary, the same measurement as described above is performed at different measurement depths by changing the mounting position of the measurement unit on the rotating rod.

(6) Confirmation of measurement results a. Investigate the measurement result, and if the measured value exceeds the standard measurement error of the measuring instrument, measure again by rotating clockwise and counterclockwise.
b. The measurement value with the smaller measurement error in both rotation directions is adopted at each measurement position, or the average value of the measurement values in both rotation directions is used as the measurement value.

  As described above, if a non-destructive measuring jig according to the present invention and a concrete covering thickness measuring device having a conventional reinforcing bar probe attached thereto are used, it is possible to easily measure even an SC pile that has conventionally been difficult to measure the concrete covering thickness. can do.

  If a probe of another nondestructive inspection apparatus conventionally used in place of the reinforcing bar probe is attached to the measuring section, various nondestructive measurements can be performed with a ready-made hollow tube.

  The nondestructive measuring jig according to the present invention is useful when performing nondestructive measurement from the inner wall side to the inner part in a long-sized hollow tube having a small inner diameter. Moreover, the concrete covering thickness measuring apparatus and the concrete covering thickness measuring method in the SC pile according to the present invention can be suitably used for grasping the entire image of the concrete covering thickness in the arranged SC pile.

I: Nondestructive measurement jig, A: Operation unit, B: Center riser unit, C: Measurement unit,
B '... Center riser part, C' ... Measurement part,
DESCRIPTION OF SYMBOLS 1 ... Rotating rod, 2-1 ... Rod coupling, 2-2 ... Rod coupling, 3 ... Detector mounting part, 4 ... Operation part support leg, 5 ... Operation panel,
10: Measuring unit fixing frame,
20 ... Measuring unit support leg, 21 ... Measuring unit arm extendable leg, 22 ... Measuring unit arm extension leg, 23 ... Spring,
30 ... Detector mounting portion, 31 ... Base plate, 32 ... Joint block, 33 ... Wheel, 34 ... Spacer plate, 35 ... Protective angle (protective case),
40 ... balancer support leg, 41 ... balancer,
50 ... Center riser fixing frame, 51 ... Fixing ring,
60 ... Centrizer, 61 ... Bearing, 62 ... Bearing fixing nut,
70 ... Center riser support legs, 71 ... Center riser extendable legs, 72 ... Centrizer legs, 73 ... Fixing nuts,
DESCRIPTION OF SYMBOLS 80 ... Wheel 90 ... Operation panel, 91 ... Operation part support leg, 92 ... Fixing clamp, 93 ... Bearing, 94 ... Rotating rod, 95 ... Rotating handle, 96-1 ... Input gear (gear), 96-2 (A ) ... intermediate gear (gear), 96-2 (B) ... intermediate gear (gear), 97 ... rotation angle plate, 98 (A) ... circular protractor, 98 (B) ... circular protractor, 99 ... indicator needle,
II ... Concrete covering thickness measuring device, 100 ... SC pile, 101 ... Concrete, 102 ... Main reinforcement, 103 ... Outer iron plate, 104 ... Hollow part, 105 ... Inner wall of SC pile, 106 ... Outer peripheral surface of SC pile,
X: Cover thickness,
200 ... Rotating rod, 201 ... Rod coupling,
300 ... Measuring unit support leg, 301 ... Rebar probe probe, 302 ... Balancer support leg, 303 ... Balancer, 304 ... Probe cable, 305 ... Rebar probe display device,
400 ... Center riser support legs,
500: Operation unit support leg, 501: Fixing clamp, 502 ... Rotating handle, 503 ... Rotating angle plate, 504 ... Control panel

Claims (7)

  A non-destructive measurement jig installed in a hollow portion of a hollow pile, the measurement unit for fixing a non-destructive measurement detector installed close to the inner wall of the hollow pile, and the detector An operation portion for moving the inner wall in the circumferential direction, and a rotational drive shaft of the detector, and the vicinity of the cross-sectional center of the hollow pile to support the measurement portion and the operation portion in the radial direction on the inner wall surface of the hollow pile A non-destructive measuring jig comprising: a rotating rod arranged in a pile axis direction; and a center riser portion for fixing the rotating rod near the center of the cross section near the measurement location.   The measuring unit has one measuring unit supporting leg with a spring that is connected to the rotating rod at a right angle and extends in the radial direction of the hollow pile, and is attached to attach a detector to the tip of the measuring unit supporting leg. And a wheel for smoothly moving the detector in the circumferential direction of the inner wall, and a balancer supported and fixed to a balancer support leg is provided in the opposite direction to the rotating rod. The nondestructive measurement jig according to claim 1, wherein the jig is a nondestructive measurement jig.   The center riser part is attached to the rotating rod via a bearing, and is attached to the center riser and has a wheel at the tip, and is stretched by the inner walls of different radial cross sections of 2 to 4 hollow piles. The nondestructive measuring jig according to claim 1 or 2, further comprising 2 to 4 center riser support legs for fixing the rotating rod near the center of the cross section.   The operation unit includes a rotation handle for rotating the rotation rod via a gear, a rotation angle plate capable of displaying a rotation angle of the rotation rod and / or a rotation angle of the detector, and the rotation Operation of 2-4 legs connected at right angles to the rod, supporting the gear, rotation handle, rotation angle plate, and being installed and fixed in different radial cross sections of 2-4 different hollow piles at the opening of the hollow pile end. The jig for nondestructive measurement according to any one of claims 1 to 3 which has a part support leg.   A concrete covering thickness measuring device for a ready-made hollow tube such as a ready-made hollow pile in which any one or more of a main reinforcing bar, a PC steel bar, and a PC steel wire are arranged in a concrete pile body, A concrete covering thickness measuring apparatus using the nondestructive measuring jig according to any one of the above items, wherein a probe of a reinforcing bar probe is installed as a detector in the measuring section. .   6. The concrete covering thickness measuring device according to claim 5, wherein the ready-made hollow pile is an SC pile.   A concrete covering thickness measuring method for an SC pile that measures the concrete covering thickness of the main reinforcement in the SC pile in which the main reinforcement is arranged using the concrete covering thickness measuring device according to claim 5, wherein Positioning the rotating rod so that the measuring unit with the probe of the probe and the center riser adjusted to support the length of the support leg of the center riser can be installed at a predetermined position of the SC pile hollow part Attach the operation part to the end of the rotating rod away from the measuring part, insert the rotating rod into the SC pile hollow part from the measuring part side, and fix the operating part to the opening of the SC pile end part Then, the rotary rod is rotated by the rotary handle of the operation unit to scan the probe in the circumferential direction, and the probe is moved from the probe at the measurement position in the circumferential direction. Measuring the distance to the main reinforcement surface of the pile body, the thickness measuring method suffers Concrete SC piles, characterized in that to determine the concrete wearing thickness at the measurement position.

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