JP6812199B2 - Pile hole bottom inspection device - Google Patents

Description

The present invention relates to a pile hole bottom inspection device for inspecting whether or not the pile hole bottom of a pile hole has reached a support layer capable of securing a bearing capacity.

When a cast-in-place pile or a ready-made pile is built in a pile hole drilled in the ground, it is confirmed whether or not the bottom of the pile hole has reached a support layer that can secure a bearing capacity (Patent Document 1). reference).

Japanese Patent No. 5619263

Conventionally, in the pile hole bottom inspection method for inspecting whether or not the pile hole bottom has reached the support layer that can secure the bearing capacity, it is inspected whether or not the central portion of the pile hole bottom has reached the support layer. ..
However, when the stratum of the ground is complicated, for example, the bearing capacity may differ between the central portion of one pile hole bottom and the peripheral portion of the pile hole bottom. For example, when the diameter of the pile hole is relatively large, even when the inspection result that the central part of the pile hole bottom reaches the support layer is obtained, the peripheral part of the pile hole bottom reaches the support layer. It may not be.
The present invention whole Kuianasoko provides a pile hole bottom inspection apparatus that can confirm whether or not reached to the support layer.

The pile hole bottom inspection device according to the present invention is a pile hole bottom inspection device for inspecting whether or not the pile hole bottom of a pile hole formed in the ground reaches the support layer, and is a central axis of the pile hole. A central body that is installed so as to extend along the center, an outer pipe that is provided so as to surround the outer peripheral surface of the central body and can rotate around the central axis of the central body, and an outer pipe of the central body. A non-center that inspects the ground condition of the pile hole bottom by pressing a rotation driving means for rotating the central axis as the center of rotation and a measuring means provided on the outer pipe against a plurality of parts around the center of the pile hole bottom. Since it is equipped with a partial inspection means and a reaction force receiving device that transmits the force received from the pile hole bottom by the non-central inspection means to the hole wall on the pile hole bottom side, is the entire pile hole bottom reaching the support layer? It will be possible to confirm whether or not it is, and it will be possible to reliably take the reaction force, and it will be possible to accurately inspect whether or not the entire pile hole bottom has reached the support layer .
Further, the rotary drive means includes an annular gear provided on the outer peripheral surface so as to surround the outer peripheral surface of the outer pipe, a drive source fixed to the central body via a connecting portion, and a rotational force generated by the drive source. It is characterized in that it is provided with a transmission gear that transmits the above to the annular gear.
Further, non-central portion inspection means, so provided movably in the direction perpendicular to the center axis of the central body, it is possible to easily inspect the portions of the periphery of the central portion of Kuianasoko, pile It becomes possible to easily confirm whether or not the entire hole bottom reaches the support layer.
In addition, since a plurality of non-central inspection means are provided around the central body, it is possible to easily and quickly inspect a plurality of parts around the central portion of the pile hole bottom, and the entire pile hole bottom is a support layer. It will be possible to easily and quickly confirm whether or not the value has been reached .
Also, since the measuring means with a central portion inspection means against the central portion to inspect the ground state of the pile hole bottom Kuianasoko, examination of whether the entire Kuianasoko reaches the support layer You will be able to do it more accurately.

A side view of the pile hole bottom inspection device. It is a perspective view which shows the pile hole bottom inspection apparatus, (a) is the figure which shows the state at the time of non-operation, (b) is the figure which shows the state at the time of extension operation. It is a top view which shows the pile hole bottom inspection apparatus, (a) is a figure which shows the state at the time of non-operation, (b) is a figure which shows the state at the time of extension operation. It is a figure which shows the pile hole bottom inspection apparatus, (a) is the perspective view which shows the state at the time of a rotation operation, (b) is a plan view which shows the state at the time of a rotation operation. The perspective view which shows the moving mechanism of the pile hole bottom inspection apparatus. The vertical sectional view which shows the relationship between the outer tube side facing plate and the reaction force receiving plate side facing plate, and the rotation axis. It is a top view which shows the relationship between the outer tube side facing plate and the reaction force receiving plate side facing plate, and the rotation axis, (a) is a figure which shows the state at the time of non-operation, and (b) shows the state at the time of extension operation. Figure.

Embodiment 1
The pile hole bottom inspection method according to the first embodiment is a method of inspecting a plurality of parts of the pile hole bottom in order to inspect whether or not the pile hole bottom of the pile hole for building a pile formed in the ground reaches the support layer. This is a method for inspecting the ground condition, and the pile hole bottom inspection device for realizing the method will be described below.

As shown in FIG. 1, the pile hole bottom inspection device 1 includes a central portion inspection device 2 for inspecting the central portion of the pile hole bottom 101 and a non-central portion inspection device 3 for inspecting other than the central portion of the pile hole bottom 101. , The reaction force receiving device 4 is provided. Note that FIG. 1 shows the pile by cutting the reaction force receiving plate 43 and the arc plate 54 located below the pile hole bottom inspection device 1 shown in FIG. 2 (b) from the direction of arrow A in FIG. 2 (b). It is a figure which looked at the hole bottom inspection apparatus 1.
The pile hole bottom inspection device 1 is attached to the head 105 of a heavy machine such as an excavation bucket attachment part of a cast-in-place pile excavator or a suspension part of a lifting machine (not shown) via an attachment 106, and operates the heavy machine. It is installed at the bottom of the pile hole 101. That is, the pile hole bottom inspection device 1 is submerged in muddy water placed in the excavated pile hole 100 and installed at the pile hole bottom 101.

The central inspection device 2 is provided at the tip of the central body 21 installed so as to extend along the central axis of the pile hole 100, the hydraulic cylinder 22 installed in the central body 21, and the piston rod 24 of the hydraulic cylinder 22. It is provided with a measuring means 80 provided. Here, the central portion inspection means is configured by the measuring means 80 and the hydraulic cylinder 22 as a pressing means for pressing the measuring means 80 against the pile hole bottom 101.
For example, the central body 21 is formed in a bottomed cylindrical shape in which the cylinder 23 of the hydraulic cylinder 22 is housed and fixed, and a through hole 25 through which the piston rod 24 of the hydraulic cylinder 22 is passed is formed at the bottom of the cylinder. Has been done. By attaching a lid 21t to the upper opening of the cylinder, the cylinder 23 of the hydraulic cylinder 22 is housed and fixed in the cylinder. Then, the lid 21t attached to the upper opening of the cylinder is attached to the head 105 of the heavy machine via the attachment 106.

The reaction force receiving device 4 is a reaction force transmitting means provided so as to be connected to each position on the outer peripheral surface of the central body 21 at equal intervals in the circumferential direction and to extend in a direction orthogonal to the central axis 99 of the central body 21. A reaction force receiving plate 43 attached to the tip of each piston rod 42 of each of the hydraulic cylinders 41 and transmitting the reaction force to the hole wall 102 on the pile hole bottom 101 side of the pile hole 100. And.
The reaction force receiving plate 43 is formed of, for example, a steel plate having an outer surface 43a and an inner surface 43b having a curvature substantially corresponding to the curvature of the arc of the hole wall 102 forming the inner peripheral surface of the pile hole 100. The curvature of the arc of the hole wall 102 differs depending on the diameter of the pile hole 100 to be constructed, but the curvature corresponding to the curvature of the arc of the hole wall 102 of the pile hole 100 is provided. It may be changed to the reaction force receiving plate 43.
That is, as the reaction force transmitting means, the plurality of hydraulic cylinders 41 function as reaction force transmitting means for transmitting the reaction force received by the hydraulic cylinder 22 and the central body 21 to the reaction force receiving plate 43.
The hydraulic cylinder 41 as the reaction force transmitting means has a central angle on the upper and lower sides of the central body 21 (both ends in the extension direction of the central body 21) in the circumferential direction of the outer peripheral surface of the central body 21, for example, as shown in FIG. It is connected to each position separated by 90 °. That is, as shown in FIG. 2B, four hydraulic cylinders 41 are provided on the upper side of the central body 21 and four hydraulic cylinders 41 are provided on the lower side of the central body 21, and the positions of the central body 21 in the circumferential direction are the same. A reaction force receiving plate 43 is connected to the tips of the piston rods 42 and 42 of the upper and lower hydraulic cylinders 41 and 41 provided in the above. Then, by operating the eight hydraulic cylinders 41 at the same time, the four reaction force receiving plates 43 can be moved along the radial direction of the central body 21.

The non-central inspection device 3 is provided so as to surround the outer peripheral surface of the central body 21, and is rotatable around the central axis 99 of the central body 21. A plurality of guide means 32 connected to each position at equal intervals in the direction, a hydraulic cylinder 33 attached to each guide means 32, and a measuring means 80 provided at the tip of the piston rod 33a of the hydraulic cylinder 33. The outer pipe 31 and a plurality of guide means 32 attached to the outer pipe 31 are provided with a rotation driving means 34 for rotating the central axis 99 of the central body 21 as a rotation center. Here, the non-central portion inspection means is configured by the measuring means 80 and the hydraulic cylinder 33 as a pressing means for pressing the measuring means 80 against the pile hole bottom 101.

The lower end side (one end side) of the outer pipe 31 is supported by a rotary receiver 35 formed on the central body 21 so as not to fall off from the outer peripheral surface of the central body 21. The rotary receiver 35 has a configuration provided with an annular groove into which a circular tube portion on the lower end side of the outer tube 31 is inserted.

The rotary drive means 34 is, for example, a drive source 37 such as an annular gear 36 provided on the outer peripheral surface of the outer pipe 31 so as to surround the outer peripheral surface, and a motor or the like fixed to the central body 21 via a connecting portion 37a. And a transmission gear 38 that transmits the rotational force generated by the drive source 37 to the annular gear 36.

The guide means 32 includes a telescopic component 50 configured to be expandable and contractible along the radial direction of the central body 21, a reaction force transmitting means for transmitting the reaction force received by the non-central inspection means to the reaction force receiving plate 43, and a reaction force transmitting means. A moving means 70 for moving the hydraulic cylinder 33 along the radial direction of the central body 21 is provided.

The expansion / contraction component 50 is connected to each position on the outer peripheral surface of the outer pipe 31 at equal intervals in the circumferential direction, in a direction orthogonal to the central axis 99 of the central body 21 and in a direction along the central axis 99 of the central body 21. It is configured to include an outer pipe side facing plate 51 provided so as to extend, a reaction force receiving plate side slide mechanism 52, and the above-mentioned hydraulic cylinder 41 as a drive source.

The reaction force receiving plate side slide mechanism 52 includes a reaction force receiving plate side facing plate 53, an arc plate 54 provided on the reaction force receiving plate side facing plate 53, and a moving force transmitting means 55.

The reaction force receiving plate side facing plate 53 is provided so as to extend in a direction orthogonal to the central axis 99 of the central body 21 and a direction along the central axis 99 of the central body 21, similarly to the outer pipe side facing plate 51. ..
The outer pipe side facing plate 51 is configured such that, for example, the plate surfaces of two rectangular steel plates 51a and 51a long in the radial direction of the central body 21 face each other in parallel, and similarly, the reaction force receiving plate The side facing plates 53 are configured such that, for example, the plate surfaces of two rectangular steel plates 53a, 53a long in the radial direction of the central body 21 face each other in parallel (see FIG. 7).
Then, in the outer pipe side facing plate 51 and the reaction force receiving plate side facing plate 53, the reaction force receiving plate side of the outer pipe side facing plate 51 and the outer pipe side of the reaction force receiving plate side facing plate 53 overlap each other. It is composed. For example, as shown in FIGS. 6 and 7, two plates 53a, 53a forming the reaction force receiving plate side facing plate 53 on the outer surface of the two plates 51a, 51a forming the outer pipe side facing plate 51. The outer pipe side facing plate 51 and the reaction force receiving plate side facing plate 53 are arranged so that the inner surfaces face each other. Then, when a moving force in the radial direction is applied to the reaction force receiving plate 43 by driving the hydraulic cylinder 41, the moving force is transmitted to the arc plate 54, so that the arc plate 54 and the reaction force receiving plate side face each other. The plate 53 moves in the radial direction. When the piston rod 42 of the hydraulic cylinder 41 is extended, the force is transmitted to the arc plate 54 via the moving force transmitting means 55, and the piston rod 42 of the hydraulic cylinder 41 is retracted. When doing so, the force is transmitted to the arc plate 54 via the reaction force receiving plate 43.
Although not shown, the outer surfaces of the two plates 53a, 53a constituting the reaction force receiving plate side facing plate 53 face each other on the inner surfaces of the two plates 51a, 51a constituting the outer pipe side facing plate 51. , The outer pipe side facing plate 51 and the reaction force receiving plate side facing plate 53 may be arranged.

Further, above and below the reaction force receiving plate side end portion of the outer pipe side facing plate 51, the outer pipe side facing plate 51 and the reaction force receiving plate side facing plate 53 are arranged in the direction along the central axis 99 of the central body 21. A guide rail 56 for guiding the movement of the reaction force receiving plate side facing plate 53 is provided so as not to be separated in the direction orthogonal to the plate surfaces of the facing plates 51 and 53. As shown in FIG. 6, the guide rail 56 has one end connected to the upper end surface or the lower end surface of the plate 51a of the outer pipe side facing plate 51 and is opposed to the outer surface of the plate 51a of the outer pipe side facing plate 51. It is configured to include a facing piece 58 forming a groove 57 having a concave cross section into which the upper and lower sides of the force receiving plate side facing plate 53 enter. In addition, these outer pipes so that the outer surfaces of the two plates 53a, 53a constituting the reaction force receiving plate side facing plate 53 face each other on the inner surfaces of the two plates 51a, 51a constituting the outer pipe side facing plate 51. When the side facing plate 51 and the reaction force receiving plate side facing plate 53 are arranged, the guide rail 56 is provided above and below the outer pipe side end portion of the reaction force receiving plate side facing plate 53. May be good.

The arc plate 54 is formed of, for example, a steel plate having an outer surface 54a and an inner surface 54b having a curvature corresponding to the curvature of the arc of the inner surface 43b of the reaction force receiving plate 43, and each plate 53a constituting the reaction force receiving plate side facing plate 53. , 53a is provided so as to extend from the end of the reaction force receiving plate side. The arc plates 54, 54 are provided so as to extend in opposite directions along the circumferential direction of the central body 21 from the end portions of the plates 53a, 53a on the reaction force receiving plate side. In other words, the arc plates 54 and 54 are located on the same arc plane centered on the central axis 99 of the central body 21.
The plate 53a of the reaction force receiving plate side facing plate 53 and the arc plate 54 provided on the plate 53a are formed integrally or separately.
By providing the expansion / contraction component 50, as shown in FIGS. 2 (b) and 3 (b), it is possible to perform an extension operation of moving the arc plate 54 radially outward of the central body 21.
Further, by providing the rotation driving means 34, as shown in FIG. 4, the rotation operation of moving the arc plate 54 along the circumferential direction of the central body 21 becomes possible.

The moving force transmitting means 55 moves the arc plates 54 and 54 and the reaction force receiving plate side facing plate 53 in the radial direction as the reaction force receiving plate 43 moves in the radial direction (the radial direction of the central body 21). In addition, it is a mechanism that keeps the arc plates 54 and 54 close to the inner surface 43b of the reaction force receiving plate 43 and transmits the radial moving force applied to the reaction force receiving plate 43 to the arc plate 54.
The moving force transmitting means 55 includes, for example, a contact member 45 that contacts the inner surface 54b of the arc plate 54, and a fixing member 46 that fixes the contact member 45 to the inner surface 43b of the reaction force receiving plate 43.
The contact member 45 comes into contact with the inner surface 54b of the arc plate 54 when, for example, the arc plate 54 moves in the circumferential direction of the central body 2 along the inner surface 43b of the reaction force receiving plate 43 by the drive of the rotation driving means 34. It is formed by a rotating body called a rotatable roller.

The moving means 70 includes an outer pipe side facing plate 51 and a reaction force receiving plate configured so that the reaction force receiving plate side of the outer pipe side facing plate 51 and the outer pipe side of the reaction force receiving plate side facing plate 53 overlap each other. It is configured to include a guide hole 61 formed so as to extend to the side facing plate 53, and a moving mechanism 62 for moving the hydraulic cylinder 33 of the non-central inspection means along the guide hole 61.

The guide hole 61 is an elongated hole formed in the outer pipe side facing plate 51 so as to extend in a direction orthogonal to the central axis 99 of the central body 21 and opened at the reaction force receiving plate side end of the outer pipe side facing plate 51. And an elongated hole formed in the reaction force receiving plate side facing plate 53 so as to extend in a direction orthogonal to the central axis 99 of the central body 21 and opening at the outer pipe side end of the reaction force receiving plate side facing plate 53. The opening side of each elongated hole is configured to overlap in a direction orthogonal to the plate surface of each of the opposing plates 51 and 53.

As shown in FIG. 5, the moving mechanism 62 has a rotating shaft 67 so that the rotational force of a drive source 63 such as a motor fixed to the hydraulic cylinder 33 of the non-central inspection means meshes with the worm wheel 64 and the worm wheel 64. It is transmitted to the rotating shaft 67 via a worm gear 66 composed of the worm 65 formed in the above, and pinions 68 attached to both ends of the rotating shaft 67 are meshed with a rack 73 described later in the guide hole 61. is there. The rotating shaft 67 is held in a through hole 72 provided in the gearbox 71 so as to be rotatable by a bearing or the like (not shown). Further, both ends of the rotating shaft 67 are provided with flanges 69, 69 that come into contact with the outer surface of the reaction force receiving plate side facing plate 53.
By providing the moving mechanism 62, the hydraulic cylinder 33 of the non-central inspection means can be moved in the radial direction of the central body 21 via the guide hole 61.

As shown in FIG. 6, the guide hole 61 is provided with a rack 73 on which the pinion 68 meshes with the lower surface of the plates 51a, 53a of the facing plates 51, 53 on the outer surface side, and the plates of the facing plates 51, 53. The structure is provided with a holding hole 74 for sandwiching the rotating shaft 67 on the inner surface side of the 51a and 53a. That is, at both ends of the rotating shaft 67, a pair of pinions 68 and 68 that mesh with the pair of racks 73 and 73 provided on the outer tube side facing plate 51 and a pair of pinions 68 and 68 provided on the reaction force receiving plate side facing plate 53. A pair of pinions 68 and 68 that mesh with the racks 73 and 73 are provided, and the shaft portions at both ends of the rotating shaft 67 are a pair of holding holes 74 and a reaction force receiving plate side facing plate 53 provided in the outer tube side facing plate 51. It is configured to be sandwiched between a pair of holding holes 74 provided in. With this configuration, the rotating shaft 67 and the holding hole 74 come into contact with each other to transmit the reaction force, so that the reaction force can be prevented from being applied to the pinion 68 and the rack 73.
That is, the reaction force received by the non-central inspection means is transmitted to the reaction force receiving plate 43 via the rotating shaft 67, the holding holes 74, the facing plates 51 and 53, and the fixing member 46, which constitute the reaction force transmitting means. It is configured so that it can be done.

The measuring means 80 is, for example, a means that is simply pressed against the ground of the pile hole bottom 101, or a means that simply penetrates into the ground of the pile hole bottom 101.
When the measuring means 80 is configured by a means that is simply pressed against the ground of the pile hole bottom 101, for example, a pressing portion such as a pressing plate that presses the ground of the pile hole bottom 101, the pressing portion is pressed by a pressing means such as a hydraulic cylinder. The amount of extension of the piston rod of the hydraulic cylinder or the amount of deformation of the ground (the amount of sinking of the ground) until the pressing portion cannot be pressed after the pressing portion is brought into contact with the ground of the pile hole bottom 101. , Or the pressing resistance or the like may be used as the evaluation value. The pressing portion as the measuring means 80 is formed by, for example, forming the tip portion into a curved surface shape, a spherical shape, a flat shape, or the like to increase the area of contact with the ground of the pile hole bottom 101. It is preferable to use one that is configured so as not to penetrate the ground of the pile hole bottom 101.
Further, when the measuring means 80 is configured by a means for simply penetrating into the ground of the pile hole bottom 101, for example, a penetrating portion such as a penetrating rod penetrating into the ground of the pile hole bottom 101, the penetrating portion is formed by a pressing means such as a hydraulic cylinder. The amount of extension of the piston rod of the hydraulic cylinder, the amount of penetration of the penetration, or the penetration resistance until the penetration cannot be pressed after the penetration is brought into contact with the ground of the pile hole bottom 101. Etc. may be used as the evaluation value. The intrusion portion as the measuring means 80 is formed on the ground of the pile hole bottom 101, for example, by forming the tip portion into a conical shape, a pyramid shape, a sharp shape, an arrowhead shape, a columnar shape, or the like. It is preferable to use one that is configured so that it can easily penetrate the ground of the pile hole bottom 101 by reducing the contact area.

The amount of extension of the piston rod of the hydraulic cylinder, the amount of deformation of the ground (the amount of sinking of the ground), and the amount of penetration of the intrusion part as the above-mentioned evaluation values are the displacement sensor (stroke sensor) and distance measurement which are not shown in the figure as measuring instruments. It may be measured with a sensor or the like. Further, the pressing resistance and the penetration resistance as the evaluation values described above may be measured by the amount of hydraulic pressure supplied to the hydraulic cylinder.

The operation of the pile hole bottom inspection device 1 will be described.
First, the head 105 of the heavy machine and the lid 21t of the central body 21 are connected via the attachment (connecting means) 106, and the heavy machine is operated to move the pile hole bottom inspection device 1 to the pile hole bottom 101.
Then, the stretching operation is performed. That is, each hydraulic cylinder 41 as a reaction force transmitting means is driven to press the reaction force receiving plate 43 against the hole wall 102 on the pile hole bottom 101 side to take the reaction force.
Then, the strength of the ground at the center of the pile hole bottom 101 is inspected by driving the hydraulic cylinder 22 of the central inspection means and pressing the measuring means 80 against the ground at the center of the pile hole bottom 101.
Further, after driving the moving mechanism 62 and the rotary driving means 34 to move each hydraulic cylinder 33 of the non-central inspection means to a desired position in the circumferential direction and the radial direction of the central body 21, each hydraulic cylinder 33 is moved. By driving and pressing the measuring means 80 against the ground other than the central portion of the pile hole bottom 101, the strength of the ground other than the central portion of the pile hole bottom 101 is inspected.

The strength of the ground of the pile hole bottom 101 may be determined using the above-mentioned evaluation value.
In this case, the standard evaluation value required for the support layer is obtained in advance by an experiment, and if the measured evaluation value reaches the standard evaluation value, it is determined that the ground of the pile hole bottom 101 has reached the support layer. If the measured evaluation value does not reach the standard evaluation value, the bottom of the pile hole 100 is further excavated to deepen the depth of the pile hole, and then the measurement is performed again, and the measured evaluation value reaches the standard evaluation value. To deepen the depth of the pile hole.
Then, after the evaluation value of the ground of the pile hole bottom 101 reaches the standard evaluation value, an iron cage is inserted into the pile hole, the muddy water in the pile hole is replaced with concrete, and a cast-in-place concrete pile is constructed. This makes it possible to construct a highly reliable cast-in-place concrete pile in which the pile bottom side is reliably supported by the support layer.

According to the pile hole bottom inspection device 1 according to the first embodiment, the strength of the ground at a plurality of non-central portions and the central portion of the pile hole bottom 101 can be measured, so that the entire pile hole bottom reaches the support layer. It will be possible to easily and accurately confirm whether or not it is. That is, it becomes possible to inspect the ground condition of a plurality of portions of the pile hole bottom 101, and it becomes possible to confirm whether or not the entire pile hole bottom reaches the support layer.
Further, since the central body 21 is provided and the non-central inspection means is provided so as to be movable in the direction orthogonal to the central axis 99 of the central body 21 and the circumferential direction of the central body 21, the pile hole bottom 101 It is possible to easily inspect a plurality of parts around the central part.
Further, since a plurality of non-central portion inspection means are provided around the central body 21, it is possible to easily and quickly inspect a plurality of portions around the central portion of the pile hole bottom 101.
Further, since the non-central inspection means is provided with the reaction force receiving device 4 for transmitting the force received from the pile hole bottom 101 to the hole wall 102 on the pile hole bottom 101 side, the reaction force can be reliably taken. Therefore, it becomes possible to accurately inspect whether or not the entire pile hole bottom reaches the support layer.

A pressure detecting means such as an earth pressure gauge is attached to the contact surface of the measuring means 80 with the ground, and for example, the earth pressure gauge moved to the bottom 101 of the pile hole detects the earth pressure and then a predetermined earth pressure value. By measuring the amount of extension of the piston rod until the measurement of the earth pressure, the amount of extension of the piston rod from the detection of the earth pressure until the predetermined earth pressure value is measured is the rigidity of the ground of the pile hole bottom 101. May be used as an evaluation value for evaluating. In this case as well, the reference evaluation value required for the support layer is obtained in advance by experiment, and if the measured evaluation value reaches the reference evaluation value (that is, the measured evaluation value (extension amount of the piston rod) is the reference evaluation. If it is less than or equal to the value (extension amount of the piston rod), it is judged that the ground of the pile hole bottom 101 has reached the support layer, and if the measured evaluation value does not reach the reference evaluation value (that is, When the measured evaluation value (extension amount of the piston rod) is larger than the standard evaluation value (extension amount of the piston rod), the bottom of the pile hole 100 is further excavated to deepen the depth of the pile hole, and then again. The measurement may be performed and the depth of the pile hole may be increased until the measured evaluation value reaches the reference evaluation value.
Further, the earth pressure value when the earth pressure gauge of the measuring means 80 is pressed against the ground by supplying a constant oil pressure to the hydraulic cylinder to extend the piston rod may be used as an evaluation value.
Further, a hardness meter may be provided on the contact surface of the measuring means 80 with the ground, and the hardness value measured by the hardness meter pressed against the ground may be used as the evaluation value.

Further, in the above description, the configuration including the moving means 70 for moving the non-central portion inspection means along the radial direction of the central body 21 is illustrated, but the configuration may not include the moving means 70. For example, the hydraulic cylinder 33 as the non-central portion inspection means may be fixed to the outer pipe side facing plate 51 or the reaction force receiving plate side facing plate 53.

Further, the hydraulic cylinder of the reaction force receiving device is composed of one hydraulic cylinder provided so as to extend in the radial direction of the pile hole 100, and the cylinder of this hydraulic cylinder is orthogonal to the central axis of the hydraulic cylinder in the vertical direction. As described above, the pile hole bottom inspection device may have a structure in which the hydraulic cylinder 22 of the central inspection means and the hydraulic cylinder 33 of the non-central inspection means are fixed. In this case, a reaction force receiving plate 43 provided at the tip of a piston rod of one hydraulic cylinder provided so as to extend in the radial direction of the pile hole 100 and a reaction force receiving plate 43 provided at the bottom end of the cylinder of the hydraulic cylinder. And may be stretched against the hole wall 102 on the bottom 101 side of the pile hole to take the reaction force.
That is, if the reaction force of the non-central part inspection means and the central part inspection means can be taken, the hydraulic cylinder of the reaction force receiving device may be configured by one as described above, or as described in the first embodiment. It may be composed of a plurality of.

Further, as the pressing means for the non-central inspection means and the central inspection means, a pressing means other than the hydraulic cylinder may be used.

It should be noted that, by inspecting a plurality of parts around the central portion of the pile hole bottom 101 using a pile hole bottom inspection device not provided with a central portion inspection means, it is inspected whether or not the pile hole bottom reaches the support layer. You may try to do it. Since it is unlikely that the support layer is reached except for the central portion of the pile hole bottom 101 and only the central portion of the pile hole bottom 101 does not reach the support layer, a plurality of parts around the central portion of the pile hole bottom are inspected. Even when a pile hole bottom inspection device equipped with non-central inspection means and not provided with central inspection means is used, it is possible to accurately inspect whether the entire pile hole bottom reaches the support layer. It is thought that

Embodiment 2
A pile hole configured by attaching an attachment having at least the non-central inspection means of the central inspection means and the non-central inspection means to the excavation means such as the excavation bucket of the cast-in-place pile excavator and the head of the earth auger. It may be used as a bottom inspection device.
In this case, the non-central inspection means may be the one having the configuration described in the first embodiment, or may be provided in the excavation means such as the excavation bucket of the cast-in-place pile excavator or the head of the earth auger, and the excavation means. It may be configured to include a measuring instrument. In this case, for example, a soil pressure gauge or a hardness tester is used as a measuring instrument, and the excavation means is operated by a heavy machine such as a cast-in-place pile excavator or an earth auger to press a constant pressing force on the soil pressure gauge or the hardness tester provided in the excavation means. Based on the pressure value or hardness value measured by the soil pressure gauge or hardness tester pressed against the ground, it can be confirmed whether or not multiple parts around the central part of the pile hole bottom reach the support layer. Will be.

Embodiment 3
In the first and second embodiments, the pile hole bottom inspection device 1 having a configuration in which the measuring means is penetrated into the ground of the pile hole bottom 101 or the measuring means is pressed against the ground of the pile hole bottom 101 has been exemplified. The pile hole bottom inspection device 1 may be provided with a collecting portion (not shown) for collecting the earth and sand of the pile hole bottom 101, and the collecting portion may be pierced into the ground to collect the earth and sand. In this case, in addition to the support layer confirmation in the first and second embodiments, it is possible to confirm whether or not the entire pile hole bottom has reached the support layer by determining the geology based on the collected earth and sand. , The accuracy of support layer confirmation can be improved.

1 Pile hole bottom inspection device, 2 Central inspection device, 3 Non-central inspection device,
4 Reaction force receiving device, 21 centrosome, 22 hydraulic cylinder, 33 hydraulic cylinder,
80 measuring means, 100 pile holes, 101 pile hole bottoms, 102 hole walls.

Claims (5)

It is a pile hole bottom inspection device for inspecting whether the pile hole bottom of a pile hole formed in the ground reaches the support layer.
A centrosome installed so as to extend along the central axis of the pile hole,
An outer tube that is provided so as to surround the outer peripheral surface of the central body and can rotate around the central axis of the central body.
Rotational drive means for rotating the outer tube around the central axis of the centrosome,
A non-central part inspection means provided on the outer pipe and pressing the measuring means against a plurality of parts around the central part of the pile hole bottom to inspect the ground condition of the pile hole bottom .
A reaction force receiving device that transmits the force received from the bottom of the pile hole by the non-central inspection means to the hole wall on the bottom side of the pile hole.
A pile hole bottom inspection device characterized by being equipped with. The rotary drive means uses an annular gear provided on the outer peripheral surface so as to surround the outer peripheral surface, a drive source fixed to the central body via a connecting portion, and a rotational force generated by the drive source. The pile hole bottom inspection device according to claim 1, further comprising a transmission gear that transmits to an annular gear . Non-central portion inspection means, pile bottom hole inspection apparatus according to claim 1 or claim 2, characterized in that provided movably in the direction perpendicular to the center axis of the central body. Centrosome pile hole bottom inspection apparatus according to any one of claims 1 to 3, characterized in that a plurality of non-central portion inspection means around. The pile according to any one of claims 1 to 4 , characterized in that a central portion inspection means for inspecting the ground condition of the pile hole bottom by pressing the measuring means against the central portion of the pile hole bottom is provided. Hole bottom inspection device.

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