JP7122064B2 - Pull-out test structure, ground reinforcement structure construction method, pull-out test equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a natural ground reinforcement structure that supports the natural ground with rock bolts driven into the natural ground such as a tunnel, a pull-out test apparatus used for construction of the natural ground reinforcement structure, and a pull-out test structure .

Conventionally, a rock bolt pull-out test has been performed in order to confirm that a rock bolt driven into the natural ground in a mountain tunnel or the like is firmly fixed to the natural ground. Normally, this lock bolt pull-out test is carried out by inserting a center hole jack through a bearing plate to the protruding part of the rock bolt from the ground, screwing a test nut onto the lock bolt from the rear side of the center hole jack, While reading the hydraulic pressure gauge, the hydraulic pump applies a stepped load of 1 ton to the lock bolt, and the dial gauge reads the elongation of the lock bolt (see Non-Patent Document 1).

Also, the elongation of the rock bolt 202 driven into the ground 201 is grasped by the device configuration shown in FIGS. 18 and 19 . In this device configuration, a tension bar 203 is screwed to the outer circumference of the lock bolt 202 , and a pressure plate 204 is fitted over the lock bolt 202 and placed in contact with the driving surface 205 . Further, an angle adjusting base 206 is fitted onto the tension bar 203 so as to abut on the bearing plate 204, and a center hole jack 208 having an angle adjusting spherical seat 207 at its tip is fitted onto the tension bar 203, A center hole jack 208 is arranged so as to receive the angle adjustment spherical seat 207 on the angle adjustment seat 206 .

Then, the measurement plate 209 and the washer 210 are externally inserted on the tension bar 203 from the opposite side of the center hole jack 208 to the angle adjusting ball seat 207, and the test nut 211 is screwed. 212 is attached, and the probe 213 of the dial gauge 212 is brought into contact with the measuring plate 209 fixed to the tension bar 203 . With this device configuration, pressure is applied while the hydraulic pressure gauge 215 is being read by the hydraulic pump 214, the pullout force is applied to the tension bar 203 and the lock bolt 202 by the center hole jack 208, and the displacement of the measuring plate 209 is measured by the dial gauge 212. , the elongation of the lock bolt 202 is recognized.

[Reference material] Pullout test of rock bolt, [online], searched on March 12, 2018, Internet <URL: http://www.ktr.mlit.go.jp/ktr_content/content/000622591.pdf>

By the way, in the pull-out test of Non-Patent Document 1, after the lock bolt pull-out test is completed, the test nut on the rear side of the center hole jack is removed, and after removing the center hole jack, a normal nut is newly screwed on the lock bolt. need to reconcile. 18 and 19, the test nut 211, washer 210, and measuring plate 209 were removed after the lock bolt 202 was pulled out, and the center hole jack 208, angle adjustment base 206, and tension bar were removed. After removing 203 , it is necessary to re-thread the lock bolt 202 with the normal nut 216 . Therefore, removing the test nut and replacing the nut by attaching the normal nut took a lot of time and effort, which led to a decrease in construction efficiency.

The present invention is proposed in view of the above problems, and it is possible to construct a ground reinforcement structure by confirming the fixing state of rock bolts, and a test nut that is screwed during a pull-out test on the rock bolts. To provide a construction method for a natural ground reinforcement structure, a pull-out test apparatus used for construction of a natural ground reinforcement structure, and a pull-out test structure that can improve workability by eliminating the need to replace a normal nut with a nut. aim.

The pull-out test structure of the present invention includes a first rock bolt driven into the natural ground, a second rock bolt different from the first rock bolt, and the first rock bolt driven into the natural ground. A normal nut that is screwed into a first male screw projecting from a setting surface, is screwed in such that the first bearing pressure plate is substantially in contact with the driving surface, and is left in the natural ground to constitute a natural ground reinforcement structure. and a second male screw protruding from the driving surface of the second lock bolt, and a second bearing plate different from the first bearing plate is substantially abutted against the driving surface. and a pull-out test nut different from the normal nut that is left in the ground and constitutes the ground reinforcement structure, and a pull-out test nut that is arranged on the outer periphery of the pull-out test nut and abuts the second bearing plate. An approximately annular angle adjustment base and a pull-out force loading jack, which is a pull cylinder jack that outputs a pulling force arranged on the angle adjustment base, are provided, and the pull-out test nut is fitted to the connector of the pull-out force loading jack. It is characterized in that it is formed in a flexible shape, and the pull-out force loading jack is fitted to the pull-out test nut via the connector .
According to this, by performing a pull-out test by fitting the connector of the pull-out force loading jack to the pull-out test compliant nut, it is possible to confirm the fixing state of the rock bolt and construct the rock ground reinforcement structure. The pull-out test nut, which is screwed to the second lock bolt and the second bearing plate is substantially in contact with the driving surface, can be left as it is after the pull-out test and used as a nut that performs the same function as a normal nut . This eliminates the need to change the nut between the test nut that is screwed to the lock bolt during the pull-out test and the normal nut, thereby improving workability. Furthermore, by forming the pull-out test nut into a shape that can be freely fitted to the connector of the pull-out force loading jack, there is no need to attach a tension bar extending from the lock bolt, which also simplifies the construction work. It is possible to improve the workability, and it is also possible to reduce the number of parts of the pull-out test apparatus and reduce the construction cost. Further, by using a pulling cylinder jack as the pull-out force loading jack, the pull-out force loading jack can be made lighter and smaller, and the work of mounting and removing the pull-out force loading jack can be facilitated. Therefore, it is possible to facilitate the installation and removal of other constituent members of the pull-out test apparatus, such as the angle adjusting pedestal provided around the pull-out force loading jack, and the pull-out test apparatus as a whole. In particular, when the lock bolts are driven laterally or upwardly into the inner peripheral surface of the tunnel, the merit of simplification of these operations is remarkable. Moreover, the cost required for the pull-out force loading jack can be reduced.

The pull-out test structure of the present invention is characterized in that the nut for pull-out test is provided with a fitting portion that can be freely fitted to the connector by rotating the connector.
According to this, it is possible to easily engage and disengage the connector from the nut corresponding to the pull-out test by rotating the connector of the pull-out force loading jack. , the removal work can be facilitated. Therefore, it is possible to facilitate the installation and removal of other constituent members of the pull-out test apparatus, such as the angle adjusting pedestal provided around the pull-out force loading jack, and the pull-out test apparatus as a whole. In particular, when the lock bolts are driven laterally or upwardly into the inner peripheral surface of the tunnel, the merit of simplification of these operations becomes remarkable.

The pull-out test structure of the present invention is characterized in that the angle-adjusting spherical seat of the pull-out force loading jack is brought into contact with the receiving portion of the angle-adjusting base, and the pull-out force loading jack is arranged on the angle adjusting base.

The construction method of the ground reinforcement structure of the present invention comprises: driving a first rock bolt into the ground ; A normal nut that is left behind and constitutes the ground reinforcement structure is screwed in, and the first bearing plate interposed between the driving surface and the normal nut is substantially abutted against the driving surface, and the A second lock bolt different from the first lock bolt is driven into the natural ground, and a pull-out test different from the normal nut is applied to the second male thread of the second lock bolt projecting from the driving surface. A corresponding nut is screwed to bring a second bearing pressure plate , different from the first bearing pressure plate , interposed between the driving surface and the pull-out test corresponding nut, into substantial contact with the driving surface. In step 1, a substantially annular angle adjusting pedestal is arranged on the outer periphery of the pull-out test nut and brought into contact with the second bearing plate, and a pull-out force loading jack, which is a pull cylinder jack that outputs a pulling force, is set at the above angle. The connector is fitted to the pull-out test nut which is arranged on the adjustment pedestal and has a shape that can be freely fitted to the connector of the pull-out force loading jack. a second step of applying a pull-out force to the second lock bolt via a nut and performing a pull-out test; a third step of removing the connecting member and the pull-out force loading jack by leaving the connecting member screwed with the lock bolt 2 to release the connecting member from the fitted state;
According to this, for example, a pull-out test can be performed at any time in conjunction with the work of driving the first and second lock bolts, or in parallel with the work of driving the first and second lock bolts. It is possible to perform a pull-out test or the like on another second lock bolt that has already been placed, and the degree of freedom in pull-out test work and construction work can be increased. In addition, by performing a pull-out test by fitting the connector of the pull-out force loading jack to the pull-out test nut, it is possible to confirm the fixing state of the rock bolt and construct the ground reinforcement structure. After the pull-out test, the pull-out test nut, which is screwed to the lock bolt and the second bearing plate is substantially in contact with the driving surface, can be left as it is and used as a nut that performs the same function as a normal nut . It is possible to eliminate the need to change the nut between the test nut screwed in the pull-out test for the lock bolt and the normal nut, and improve workability. Furthermore, by forming the pull-out test nut into a shape that can be freely fitted to the connector of the pull-out force loading jack, there is no need to attach a tension bar extending from the lock bolt, which also simplifies the construction work. It is possible to improve the workability, and it is also possible to reduce the number of parts of the pull-out test apparatus and reduce the construction cost. Further, by using a pulling cylinder jack as the pull-out force loading jack, the pull-out force loading jack can be made lighter and smaller, and the work of mounting and removing the pull-out force loading jack can be facilitated. Therefore, it is possible to facilitate the installation and removal of other constituent members of the pull-out test apparatus, such as the angle adjusting pedestal provided around the pull-out force loading jack, and the pull-out test apparatus as a whole. In particular, when the lock bolts are driven laterally or upwardly into the inner peripheral surface of the tunnel, the merit of simplification of these operations becomes remarkable. Moreover, the cost required for the pull-out force loading jack can be reduced.

The construction method of the ground reinforcement structure of the present invention comprises: the extraction force loading jack; A displacement detection unit for detecting the displacement of the bolt is incorporated and a data transmission processing unit is provided, and in the second step, the data transmission processing unit corresponds to the pressure data acquired from the pressure detection unit or the pressure. data of the load applied is wirelessly transmitted to a data recording device, and data of displacement of the second rock bolt obtained from the displacement detection unit is wirelessly transmitted to the data recording device.
According to this, the existing pull-out test required at least two workers, one to read the hydraulic pressure with the hydraulic gauge and the other to read the displacement of the lock bolt, whereas one worker was required to read the hydraulic pump. Withdrawal force is applied, and the same worker uses the pressure data wirelessly transmitted to the data recording device or the load data generated from the pressure data and wirelessly transmitted, and the displacement data wirelessly transmitted to the data recording device. related information can be confirmed, and even a single operator can efficiently and accurately perform the pull-out test. In addition, the record of the pull-out test can be recorded in the data recording device on the spot and saved. Further, since data is wirelessly transmitted from the data transmission processing unit to the data recording device, wiring work for connecting the data recording device and the data transmission processing unit is not necessary. In addition, by incorporating the pressure detection unit and the displacement detection unit into the pull-out force loading jack, there is no need to separately install a displacement gauge, etc., and the installation work and removal work of the pull-out test apparatus as a whole can be facilitated. .

The method for constructing a rock reinforcement structure according to the present invention is characterized in that the data transmission processing unit is housed in a waterproof case.
According to this, even when construction is carried out outdoors in mountain tunnels with a lot of water leakage or in rainy weather, the waterproof case prevents water from entering the data transmission processing unit, enabling stable execution of pull-out tests and data recording. be able to.

The pull-out test apparatus of the present invention is a pull-out test apparatus used in the pull-out test structure of the present invention, which is installed in the pull-out force loading jack and is a pressure detector for detecting the hydraulic pressure input to the pull-out force loading jack. a displacement detection unit that is installed in the pull-out force loading jack and detects displacement of the second lock bolt to which the pull-out force is loaded; a data transmission processing unit that is attached to the pull-out force loading jack; A recording device is provided, and the data transmission processing unit wirelessly transmits the pressure data acquired from the pressure detection unit or the load data corresponding to the pressure to the data recording device, and the data acquired from the displacement detection unit. It is characterized in that the displacement data of the second rock bolt is wirelessly transmitted to the data recording device.
According to this, the existing pull-out test required at least two workers, one to read the hydraulic pressure with the hydraulic gauge and the other to read the displacement of the lock bolt, whereas one worker was required to read the hydraulic pump. Withdrawal force is applied, and the same worker uses the pressure data wirelessly transmitted to the data recording device or the load data generated from the pressure data and wirelessly transmitted, and the displacement data wirelessly transmitted to the data recording device. related information can be confirmed, and even a single operator can efficiently and accurately perform the pull-out test. In addition, the record of the pull-out test can be recorded in the data recording device on the spot and saved. Further, since data is wirelessly transmitted from the data transmission processing unit to the data recording device, wiring work for connecting the data recording device and the data transmission processing unit is not required. In addition, by incorporating the pressure detection unit and the displacement detection unit into the pull-out force loading jack, there is no need to separately install a displacement gauge, etc., and the installation work and removal work of the pull-out test apparatus as a whole can be facilitated. .

According to the present invention, it is possible to construct a ground reinforcement structure by confirming the anchoring state of the rock bolts, and to change the nut between the test nut that is screwed during the pull-out test for the rock bolt and the normal nut. It is possible to eliminate the necessity and improve workability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross-sectional explanatory diagram of a natural ground reinforcement structure according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of main parts of the natural ground reinforcement structure of the embodiment; (a) is a front view of a pull-out test compliant nut used in the ground reinforcement structure of the embodiment, and (b) is a cross-sectional view taken along line AA of FIG. (a) is a front view of a connector for a pull-out force loading jack used when constructing the ground reinforcement structure of the embodiment, and (b) is a cross-sectional view taken along the line BB of FIG. (a) is a perspective view of a pull-out test compliant nut, (b) is a perspective view of a connector of a pull-out force loading jack. FIG. 4 is a perspective explanatory view for explaining an operation of fitting a pull-out test compliant nut and a pull-out force loading jack connector. (a) to (c) are explanatory front views for explaining the operation of fitting the pull-out test nut and the pull-out force loading jack connector, and (d) is an enlarged cross-sectional view taken along the line CC of FIG. FIG. 3 is a perspective exploded explanatory view for explaining attachment of a pull-out test compliant nut screwed to a lock bolt and a connector of a pull-out force loading jack. (a) to (c) are cross-sectional explanatory views for explaining a construction procedure in which a pull-out test is performed on a lock bolt screwed with a pull-out test nut, the pull-out test device is removed, and the pull-out test nut is left. FIG. 4 is an explanatory diagram showing a state in which a pull-out test apparatus is installed on a lock bolt to which a pull-out test compliant nut is screwed. FIG. 4 is an enlarged partial cross-sectional side view showing the periphery of a pull cylinder jack in a state where a pull-out test apparatus is installed on a lock bolt to which a pull-out test compliant nut is screwed. FIG. 4 is an enlarged cross-sectional view showing the periphery of a pull cylinder jack in a state where a pull-out test apparatus is installed on a lock bolt to which a pull-out test compliant nut is screwed. A block diagram of a data recording device in the pull-out test apparatus. (a) is a perspective view of another example of a pull-out test compliant nut used in the ground reinforcement structure of the embodiment, and (b) is a perspective view of another example of a connector of a pull-out force loading jack. FIG. 11 is a perspective explanatory view for explaining an operation of fitting a pull-out test compliant nut of another example and a connector of a pull-out force loading jack of another example. FIG. 11 is an exploded perspective view for explaining attachment of a pull-out test compliant nut of another example and a pull-out force loading jack of another example, which are screwed together with the lock bolt. FIG. 13 is an enlarged cross-sectional view corresponding to FIG. 12 when a modified pulling cylinder jack is used; FIG. 2 is an explanatory view showing a conventional rock bolt pull-out test apparatus. (a) to (c) are partial cross-sectional explanatory views for explaining the construction procedure of performing a pull-out test on a rock bolt with a conventional lock bolt pull-out test apparatus, removing the pull-out test apparatus, and re-threading a normal nut.

[Embodiment ground reinforcement structure, its construction method , and pull-out test structure ]
As a ground reinforcement structure according to an embodiment of the present invention, a structure for reinforcing the ground 101 of a tunnel is shown in FIGS. 1 and 2. FIG. In this natural ground reinforcement structure, the shotcrete 103 is provided on the inner peripheral surface of the natural ground 101 on the tunnel space 102 side, and the inner peripheral surface of the shotcrete 103 corresponds to the placement surface of the natural ground 101 with the rock bolts 1a and 1b. is a driving surface 104 of . A hole 105 is formed in the shotcrete 103 and the natural ground 101 so as to be substantially perpendicular to the placement surface 104, and rock bolts 1a and 1b are placed in the hole 105 and a fixing material such as a cement mortar fixing material. 106 is filled. In addition, 107 in FIG. 1 is secondary lining concrete.

A rock bolt 1a corresponding to a first rock bolt and a rock bolt 1b corresponding to a second rock bolt placed in the rock ground 101 and the shotcrete 103 are inserted into the hole 105 from the rear end surface of the rear end portion. Male threads 11a and 11b are formed to reach a length. The lock bolts 1a and 1b, which correspond to the first and second lock bolts in this embodiment, are rod-shaped members having the same shape, structure, and size, but may be members having different shapes, structures, or sizes. is.

A pressure plate 2a corresponding to a first pressure plate is externally inserted through an insertion hole 21a on the male screw 11a projecting from the driving surface 104 of the lock bolt 1a, and the male screw 11b projecting from the driving surface 104 of the lock bolt 1b has a A pressure plate 2b corresponding to a second pressure plate is inserted through the insertion hole 21b. The bearing plates 2a and 2b corresponding to the first and second bearing plates in this embodiment are plate-like members having the same shape, structure and size, and square washers or the like are used as the bearing plates 2a and 2b. , members of different shapes, configurations or sizes.

A normal nut 3 such as a normal hexagonal nut is screwed onto the external thread 11a protruding from the driving surface 104 of the lock bolt 1a, and the pressure plate 2a is screwed so as to substantially abut against the driving surface 104. . A pull-out test nut 4 different from the normal nut 3 is screwed onto the male thread 11b protruding from the driving surface 104 of the lock bolt 1b, and the bearing plate 2b is screwed so as to substantially abut against the driving surface 104. is entered.

The pull-out test nut 4 is formed in a shape that can be freely fitted to a connector 5 of a pull-out force loading jack 6, which will be described later, and as shown in FIGS. It has a base body 41 with a screw hole 42 formed over its entire length, and a substantially fan-shaped vane part 44 protruding radially is provided at a rear part 43 of the base body 41 . A pair of wing portions 44 are provided at corresponding positions, and the pair of wing portions 44, 44 are formed so as to protrude in mutually opposite directions. A projection 45 protruding forward is locally formed at a predetermined position on the front surface of each wing portion 44 . The projection 45 of the other wing portion 44 and the projection 45 of the other wing portion 44 are provided at corresponding positions.

As shown in FIGS. 4 to 8, the connector 5 has a screw hole 52 formed in the rear portion of a substantially cylindrical base 51 and a keyhole-shaped mounting hole in the front portion of the base 51. 53 are formed. The rear portion 54 of the mounting hole 53 is circular and hollow, and the diameter of the rear portion 54 is formed slightly larger than the diameter of the circle obtained by extending the arcuate outer peripheral edge of the wings 44 of the pull-out test nut 4. The axial thickness of the hollow rear portion 54 is slightly larger than the thickness of the wings 44 .

A front portion 55 of the mounting hole 53 is formed in a substantially similar shape corresponding to the rear portion 43 having the wings 44 of the pull-out test nut 4, and a substantially fan-shaped protruding portion 56 is formed to protrude inward. are arranged opposite to each other. A fitting hole 57 having a shape and size corresponding to the projection 45 of the pull-out test nut 4 is locally formed at a predetermined position on the rear surface of each protrusion 56, and the fitting hole 57 in this example protrudes. The fitting hole 57 of one protrusion 56 and the fitting hole 57 of the other protrusion 56 are formed in the vicinity of the end of the rear surface of the portion 56, and are provided at corresponding positions. 57 is provided at a position corresponding to the pair of projections 45 of the pull-out test nut 4 . A portion of the front portion 55 without the projecting portion 56 is formed to have the same diameter as the rear portion 54 and has a shape continuous with the rear portion 54 .

When fitting the connector 5 to the pull-out test nut 4, as shown in FIGS. The connector 5 is externally inserted from the rear portion 43 side of the pull-out test nut 4 so that most of the pull-out test nut 4 is inserted into the mounting hole 53 . Then, the connector 5 is rotated so that the protrusions 56 and the wings 44 of the pull-out test nut 4 are overlapped, and the positions of the pair of fitting holes 57 and 57 of the connector 5 and the pull-out test are determined. The corresponding nut 4 is rotated until the positions of the pair of projections 45, 45 of the corresponding nut 4 are aligned (see the bold line arrow in FIG. 7). When the positions of the pair of fitting holes 57 and 57 and the positions of the pair of protrusions 45 and 45 are aligned, the fitting holes 57 and 57 are fitted to the protrusions 45 and 45, respectively, and the fitting hole 57 and the protrusion 45 are fitted. The connector 5 and the nut 4 corresponding to the pull-out test are fitted. This fitting can be easily removed by rotating the coupler 5 so as to shift the position of the pair of fitting holes 57, 57 and the position of the pair of projections 45, 45, and can be easily removed. .

That is, the pull-out test nut 4 of this example is provided with a protrusion 45 as a fitting portion that can be freely fitted to the connector 5 by rotating the connector 5 , and the pull-out test nut 4 connects the pull-out force loading jack 6 . In other words, the projection 45 of the pull-out test nut 4 serving as a key is key-fitted into the fitting hole 57 of the connector 5 so as to be freely fitted. ing. In this example, two pairs of projections 45 corresponding to fitting portions and two fitting holes 57 corresponding to portions to be fitted with which the fitting portions are fitted are provided. may be provided at predetermined intervals, or may be provided one by one.

Furthermore, when fitting the connector 5 to the pull-out test nut 4 when performing a pull-out test, as shown in FIGS. A substantially annular angle adjusting pedestal 7 is arranged on the outer periphery of the pull-out test nut 4 which is screwed so as to substantially abut on the driving surface 104 . A plurality of magnets 71 are provided on the bearing pressure plate 2b side of the angle adjustment pedestal 7 at predetermined intervals in the circumferential direction, and are detachably magnetically attached to the bearing pressure plate 2b made of a magnetic material (see FIG. 9B). ). The angle adjusting base 7 is formed with a receiving portion 72 having a substantially tapered surface for receiving the angle adjusting spherical seat 61 provided at the tip of the pulling force loading jack 6 on the side opposite to the bearing plate 2b side. ing.

After that, the connector 5 attached to the inside of the tip of the pull-out force loading jack 6 is externally inserted from the rear portion 43 side of the pull-out test nut 4, and the pull-out force loading jack 6 and the coupling 5 are rotated to rotate the coupling 5. and the pull-out test corresponding nut 4 are fitted, and the angle-adjusting spherical seat 61 of the pull-out force loading jack 6 is brought into contact with the receiving portion 72 of the angle adjusting base 7 to arrange the pull-out force loading jack 6 constituting the pull-out test apparatus. . Here, the angle adjusting spherical seat 61 is structured to be in contact with the angle adjusting base 7 so that the angle can be adjusted. 5. Pulling force loading jacks 6 can be installed so that their central axes are aligned.

Next, the procedure for constructing the ground reinforcement structure of this embodiment will be described. When constructing the ground reinforcement structure of this embodiment, a fixing material 106 such as cement mortar (not shown) that hardens after a predetermined period of time is injected into the perforations 105 formed in the ground 101 and the shotcrete 103 . , a rock bolt 1 a corresponding to a first rock bolt is driven into the bore 105 , and the rock bolt 1 a is driven into the ground 101 and the shotcrete 103 so as to be fixed by the fixing material 106 . Then, the male thread 11a of the lock bolt 1a protruding from the driving surface 104 of the lock bolt 1a is externally fitted with the bearing pressure plate 2a corresponding to the first bearing plate, and the normal nut 3 is screwed in order. By screwing, the pressure plate 2a interposed between the driving surface 104 and the normal nut 3 is brought into substantial contact with the driving surface 104 (see FIG. 2).

A fixing material similar to that described above is injected into a hole 105 formed separately from the hole 105 into which the lock bolt 1a is driven, and a lock bolt 1b corresponding to the second lock bolt is driven into the hole 105. The rock bolt 1b is driven into the natural ground 101 and the shotcrete 103 so as to be fixed by . Then, the male thread 11b of the lock bolt 1b protruding from the driving surface 104 of the lock bolt 1b is fitted with the bearing pressure plate 2b corresponding to the second bearing plate, and the pull-out test nut 4 different from the normal nut 3 is screwed. By screwing the pull-out test nut 4, the bearing plate 2b interposed between the driving surface 104 and the pull-out test nut 4 is substantially brought into contact with the driving surface 104 (see FIG. 2).

After that, as described above, the substantially annular angle adjustment pedestal 7 is arranged on the outer periphery of the pull-out test nut 4 , and the coupler 5 attached to the pull-out force loading jack 6 is moved from the rear portion 43 side of the pull-out test nut 4 . The pull-out force loading jack 6 and the connector 5 are rotated to fit the coupling 5 and the pull-out test nut 4, and the pull-out force loading jack 6 constituting the pull-out test device is arranged (Figs. 7 to 7). 12).

The pull-out force loading jack 6 in this embodiment is a single-acting pull cylinder jack that outputs a pulling force with a hydraulic cylinder. a spring equipped with a cylinder body 62, a plunger 63 that is housed in the cylinder body 62 and retracts when hydraulic pressure is input, and a return spring 64 that is provided on the rear side of the plunger 63 and returns the retracted plunger 63 to its initial position. It is a retractable pulling cylinder jack. A male screw 631 is formed at the front end of the plunger 63 , and by screwing the male screw 631 into the female thread of the screw hole 52 of the connector 5 , the connector 5 is inserted inside the tip of the pulling force loading jack 6 . installed. 10, the pull-out force loading jack 6 is connected through a hydraulic hose 65 to a hydraulic pump 66 that hydraulically drives the pull-out force loading jack 6. As shown in FIG. The illustrated hydraulic pump 66 is a rechargeable portable electric hydraulic pump.

The pulling force loading jack 6 has a pressure detecting portion 81 for detecting the hydraulic pressure input to the pulling force loading jack 6 and a displacement sensing portion 82 for detecting the displacement of the lock bolt 1b to which the pulling force is applied. A data transmission processing unit 83 is also provided. The data transmission processing unit 83 is housed in a waterproof case 84 made of an acrylic plate or the like, and is waterproofed so that water does not enter the data transmission processing unit 83 .

The data transmission processing unit 83 generates load data corresponding to the pressure from the pressure data obtained from the pressure detection unit 81 when a pull-out force is applied to the rock bolt 1b, and stores the load data in the data recording device. 9 in substantially real time, and the displacement data of the rock bolt 1b obtained from the displacement detector 82 is also transmitted in substantially real time to the data recording device 9 by radio. The data transmission processing unit 83 can be configured to wirelessly transmit the pressure data acquired from the pressure detection unit 81 to the data recording device 9 in substantially real time, instead of generating and transmitting the aforementioned load data. is.

The data recording device 9, to which data is wirelessly transmitted from the data transmission processing unit 83, is composed of, for example, a smartphone, a mobile information terminal, or a personal computer. , an input unit 93 such as a touch panel, keyboard, mouse, etc., an image display unit 94 such as a touch panel, a liquid crystal display, etc., and a communication unit 95 as a wireless communication interface. The storage unit 92 includes a program storage unit 921 for storing application programs such as an operation system and a drawing test processing program for processing data received from the data transmission processing unit 83, and a program storage unit 921 for storing data received from the data transmission processing unit 83 and a drawing test. A data storage unit 922 is provided for storing data generated by the processing program.

Then, in a state in which the pullout force loading jack 6 connected to the hydraulic pump 66 and provided with the data transmission processing unit 83 and the data recording device 9 constitute the pullout test device, the pullout force loading jack 6 is hydraulically moved by the hydraulic pump 66. A pullout force is applied to the lock bolt 1b corresponding to the second lock bolt by the pullout force loading jack 6 via the connector 5 and the pullout test nut 4, and a pullout test is performed (Fig. 9(a), 10 to 12).

During this pull-out test, for example, the pressure detection unit 81 continuously detects the hydraulic pressure input to the pull-out force loading jack 6, and a control unit such as a CPU, a storage unit having a program storage unit and a data storage unit is operated. Detected pressure data is continuously input to the data transmission processing unit 83 provided, and the data transmission processing unit 83 continuously generates load data corresponding to the pressure from the input pressure data, and generates The data of the load thus obtained is continuously transmitted to the data recording device 9 by radio in substantially real time or the like. At the same time, the displacement detector 82 continues to detect the displacement of the lock bolt 1b caused by the loading of the pull-out force, and the data of the detected displacement is continuously input to the data transmission processor 83 for data transmission processing. The unit 83 continuously wirelessly transmits the input displacement data to the data recording device 9 substantially in real time or the like. The data recording device 9 continuously receives load data and displacement data from the data transmission processing unit 83 in substantially real time, stores the load data and the displacement data in the data storage unit 922, and stores the load data and the displacement data in the data storage unit 922. The load-displacement relationship information such as a graph showing the displacement relationship is generated and displayed on the image display unit 94 .

In a configuration in which the data transmission processing unit 83 transmits the pressure data as it is to the data recording device 9, for example, the data transmission processing unit 83 continuously transmits the input pressure data to the data recording device 9 substantially in real time. In addition to the wireless transmission, the input displacement data is continuously wirelessly transmitted to the data recording device 9 in substantially real time or the like. The data recording device 9 continuously receives load data and displacement data from the data transmission processing unit 83 in substantially real time or the like, and continuously generates load data corresponding to the pressure from the received pressure data. , the generated load data and displacement data are respectively stored in the data storage unit 922 , and load-displacement relationship information such as a graph showing the relationship between load and displacement is generated and displayed on the image display unit 94 .

After the pull-out test is completed, as shown in FIGS. 9(b) and 9(c), the pull-out test nut 4 is left screwed to the lock bolt 1b corresponding to the second lock bolt, and the connector 5 is removed. are released, and the connector 5, the pull-out force loading jack 6, and the angle adjustment pedestal 7 are removed. In order to release the fitting state of the connector 5 from the pull-out test compliant nut 4, the connector 5 is rotated so that the projection 45 corresponding to the fitting portion and the fitting portion corresponding to the to-be-fitted portion are fitted. The fitting with the hole 57 is released, the connector 5 is rotated until the protruding portion 56 of the pull-out test nut 4 is arranged in a portion where the wing portion 44 is absent, and the pull-out test nut is inserted into the mounting hole 53 of the connector 5. This is done by removing the connector 5 so that the connector 4 is disengaged.

When the lock bolt 1b is displaced by the pull-out test and the bearing plate 2b is separated from the driving surface 104, the nut 4 corresponding to the pull-out test is screwed into the driving surface 104 side so that the driving surface 104 The bearing plate 2b interposed between the pull-out test nut 4 and the bearing surface 104 is brought into substantial contact with the driving surface 104, thereby constructing a ground reinforcement structure (see FIG. 2).

According to the present embodiment, by performing a pull-out test by fitting the connector 5 of the pull-out force loading jack 6 to the pull-out test compliant nut 4, the fixation state of the rock bolts 1b and 1a is confirmed, and the ground reinforcement structure is obtained. In addition, the pull-out test nut 4, which is screwed to the lock bolt 1b and the bearing pressure plate 2b is substantially in contact with the driving surface 104, is left as it is after the pull-out test, and has the same function as the normal nut 3. It is possible to use it as a nut that fulfills the above, and it is possible to eliminate the need to replace the normal nut with the test nut that is screwed during the pull-out test for the lock bolt 1b, and improve workability. Further, by forming the pull-out test nut 4 in a shape that can be freely fitted to the connector 5 of the pull-out force loading jack 6, there is no need to install a tension bar extending from the lock bolt 1b. can be simplified to improve the workability, and the number of parts of the pull-out test apparatus can be reduced to reduce the construction cost.

In addition, by providing the pull-out test nut 4 with a projection 45 which is a fitting portion that can be freely fitted to the connector 5 by rotating the connector 5, the connector 5 can be easily fitted to the pull-out test nut 4. In addition, the fitting can be released, and the attachment work and removal work of the connector 5 and the pull-out force loading jack 6 can be facilitated. Therefore, it is possible to facilitate the installation and removal of other components of the pull-out test apparatus, such as the angle adjusting pedestal 7 provided around the pull-out force loading jack 6, and the pull-out test apparatus as a whole. In particular, when the lock bolts 1a and 1b are driven laterally or upwardly on the driving surface 104 of the inner peripheral surface of the tunnel, the merit of simplification of these operations becomes remarkable.

Further, according to the construction method of the ground reinforcement structure of the present embodiment, a pull-out test can be performed at any time in conjunction with the operation of driving the rock bolts 1a and 1b, and the rock bolts 1a and 1b can be driven. In parallel with the work, it is possible to perform a pull-out test on another lock bolt 1b that has already been placed, and the degree of freedom in pull-out test work and construction work can be increased.

Further, by using a pulling cylinder jack as the pull-out force loading jack 6, the pull-out force loading jack 6 can be reduced in weight and size, and the work of mounting and removing the pull-out force loading jack 6 can be facilitated. Therefore, it is possible to facilitate the installation and removal of other components of the pull-out test apparatus, such as the angle adjusting pedestal 7 provided around the pull-out force loading jack 6, and the pull-out test apparatus as a whole. In particular, when the lock bolts 1a and 1b are driven laterally or upwardly on the driving surface 104 of the inner peripheral surface of the tunnel, the merit of simplification of these operations becomes remarkable. Furthermore, the cost required for the pulling force loading jack 6 can be reduced.

Further, the data transmission processing unit 83 wirelessly transmits the data of load or pressure and the data of displacement to the data recording device 9 in substantially real time or the like. While at least two workers were required to read the displacement, one worker loads the pull-out force with the hydraulic pump 66, and the load or Based on the pressure data and the displacement data, the same operator can confirm the relationship information between the load and the displacement, and even one operator can efficiently and accurately perform the pull-out test. In addition, the record of the pull-out test can be recorded in the data recording device 9 on the spot and saved. Further, since data is wirelessly transmitted from the data transmission processing unit 83 to the data recording device 9, wiring work for connecting the data recording device 9 and the data transmission processing unit 83 is not required. In addition, by incorporating the pressure detection unit 81 and the displacement detection unit 82 into the pull-out force loading jack 6, there is no need to separately install a displacement gauge, etc., and the installation work and removal work of the pull-out test apparatus as a whole are facilitated. be able to.

In addition, by housing the data transmission processing unit 83 in the waterproof case 74, water can be prevented from entering the data transmission processing unit 83 even when construction is carried out outdoors in a mountain tunnel with a lot of water leakage or in rainy weather, and the data transmission processing unit 83 is stabilized. can perform pull-out tests and record data.

[Scope of invention disclosed in this specification]
In addition to each invention and embodiment listed as an invention, the invention disclosed in this specification is specified by changing these partial contents to other contents disclosed in this specification within the applicable range, Alternatively, what is specified by adding other contents disclosed in this specification to these contents, or what is specified by deleting these partial contents to the extent that partial effects can be obtained and making them a broader concept contain. The invention disclosed in this specification also includes the following modifications and additional contents.

For example, the shape of the pull-out test nut according to the present invention that can be freely fitted to the connector is not limited to the shape having the protrusion 45 of the pull-out test nut 4, and is appropriate. For example, the pull-out test nut shown in FIGS. It is good also as a shape of 4m. The pull-out test nut 4m has a base body 41m with a screw hole 42m formed over the entire length thereof, and is provided with substantially fan-shaped wings 43m protruding in the radial direction over the entire length of the base body 41m. A pair of wing portions 43m are provided at corresponding positions, and the pair of wing portions 43m and 43m are formed so as to protrude in mutually opposite directions.

A plurality of fitting grooves 44m (two in the illustrated example) are provided at intervals in the longitudinal direction of the pull-out test nut 4m. The fitting groove 44m is formed so as to open at one side end face of the wing portion 43m and is formed to a position that does not reach the other side end face of the wing portion 44m. The plurality of fitting grooves 44m arranged in the longitudinal direction are formed so that the open sides are aligned. In addition, the open side of the fitting groove 44m of one wing portion 43m and the open side of the fitting groove 44m of the other wing portion 43m are in the same direction in the circumferential direction.

The connector 5m fitted to the pull-out test nut 4m has a screw hole 52m formed in the rear portion of the substantially cylindrical base 51m, and a mounting hole 53m formed in the front portion of the base 51m. , the diameter of the mounting hole 53m is slightly larger than the diameter of a circle obtained by extending the arc-shaped outer peripheral edge of the wing portion 43m of the pull-out test compliant nut 4m. A protrusion 54m having a length substantially corresponding to that of the fitting groove 44m is formed in the circumferential direction at the opposite position of the inner peripheral surface of the mounting hole 53m, and is spaced in the length direction of the connector 5m corresponding to the fitting groove 44m. A plurality of (two in the illustrated example) ridges 54m corresponding to the fitting grooves 44m are provided.

When the connector 5m is fitted to the pull-out test compliant nut 4m, the pull-out test compliant nut 4m is made to match the portion of the nut 4m without the wings 43m and the portion of the connector 5m with the protrusion 54m. The connector 5m is externally inserted from the rear side of the nut 4m so that most of the pull-out test nut 4m is inserted into the mounting hole 53m. Then, the connector 5m is rotated to fit the protrusion 54m of the connector 5m from the open side of the fitting groove 44m of the pull-out test nut 4m, and the protrusion 54m and the fitting groove 44m are fitted (the thick line in FIG. 15). arrow). This fitting can be released by rotating the connector 5m in the opposite direction to disengage the projection 54m from the fitting groove 44m, and is detachable.

That is, the pull-out test nut 4m of another example is provided with a fitting groove 44m as a fitting portion that can be freely fitted to the connector 5m by rotating the connector 5m, and is connected as a corresponding fitted portion. A protrusion 54m with a length of 5m is provided. Another pull-out test nut 4m and another connector 5m can be used in the same manner as the pull-out test nut 4 and connector 5 of the above embodiment (see FIG. 16).

As a modification of the connector 5 and the pull-out force loading jack 6, as shown in FIG. A pull-out force loading jack 6n may be provided with a guide groove 67n extending in the axial direction on the peripheral surface and opened at the angle adjustment ball seat 61 . In this modification, the anti-rotation pin 58n is engaged with the guide groove 67n to prevent rotation of the connector 5n, and the threaded state between the screw hole 52 of the connector 5n and the male thread 631 of the plunger 63 is reliably maintained. At the same time, the connector 5n becomes a non-removably integrated part of the pulling force loading jack 6n. On the other hand, according to the configuration in which the connector and the plunger 63 are fixed by simply screwing the plunger 63 to the external thread 631, as in the connectors 5 and 5m, the connector is detachable. It is possible to flexibly attach connectors compatible with pull-out test nuts of various shapes, and it is possible to increase the degree of freedom in pull-out tests and construction.

Further, the rock reinforcement structure of the present invention can be used as a rock reinforcement structure other than the tunnel reinforcement structure of the above embodiment. Further, the first and second lock bolts and the first and second bearing plates in the present invention may have the same construction, or may have different constructions. In addition, the placement surface of the ground in the present invention includes the placement surface of the shotcrete or the like provided on the inner periphery of the ground, as well as the placement surface where the ground is directly exposed. In addition, as the pulling force loading jack in the present invention, it is possible to use an appropriate one other than the pulling cylinder jack within the applicable range, for example, it is possible to use a double-acting cylinder jack that performs pushing and pulling hydraulically. It is possible.

INDUSTRIAL APPLICABILITY The present invention can be used, for example, when constructing a ground reinforcement structure in a tunnel or the like.

DESCRIPTION OF SYMBOLS 1a, 1b... Rock bolt 11a, 11b... Male screw 2a, 2b... Pressure plate 21a, 21b... Insertion hole 3... Ordinary nut 4... Pull-out test compliant nut 41... Base 42... Screw hole 43... Rear part 44... Feather part 45... Protrusion 4m...Nut for pull-out test 41m...Base 42m...Screw hole 43m...Wing portion 44m...Fitting groove 5...Connector 51...Base 52...Screw hole 53...Mounting hole 54...Rear part 55...Front part 56...Protrusion part 57... Fitting hole 5m Connector 51m Substrate 52m Screw hole 53m Mounting hole 54m Ridge 5n Connector 58n Anti-rotation pin 6 Extraction force loading jack 61 Angle adjustment sphere 62 Cylinder body 63 Plan Jar 631 Male screw 64 Return spring 65 Hydraulic hose 66 Hydraulic pump 6n Withdrawal force loading jack 67n Guide groove 7 Angle adjustment base 71 Magnet 72 Receiving portion 81 Pressure detecting portion 82 Displacement detecting portion 83 Data transmission processing unit 84 Waterproof case 9 Data recording device 91 Control unit 92 Storage unit 921 Program storage unit 922 Data storage unit 93 Input unit 94 Image display unit 95 Communication unit 101 Ground 102 Tunnel space 103 Shotcrete 104 Placement surface 105 Perforation 106 Fixing material 107 Secondary lining concrete 201 Ground 202 Rock bolt 203 Tension bar 204 Bearing plate 205 Placement surface 206 Angle adjustment Pedestal 207 Angle adjusting ball seat 208 Center hole jack 209 Measurement plate 210 Washer 211 Test nut 212 Dial gauge 213 Probe 214 Hydraulic pump 215 Hydraulic gauge 216 Ordinary nut

Claims (6)

a first rock bolt driven into the natural ground and a second rock bolt different from the first rock bolt;
The first lock bolt is screwed into a first male screw protruding from the driving surface of the ground, and is screwed into the ground so that the first bearing plate is substantially in contact with the driving surface. a normal nut that is left behind and constitutes the ground reinforcement structure ;
A second male screw that protrudes from the driving surface of the second lock bolt is screwed into the second lock bolt so that a second bearing plate different from the first bearing plate is substantially abutted against the driving surface. a pull-out test compliant nut different from the normal nut screwed in and left in the natural ground to constitute the natural ground reinforcement structure ;
a substantially annular angle adjustment pedestal disposed on the outer periphery of the pull-out test nut and in contact with the second bearing plate;
A pull-out force loading jack, which is a pull-cylinder jack that outputs a pull force arranged on the angle adjustment pedestal,
The pull-out test nut is formed in a shape that can be freely fitted to the connector of the pull-out force loading jack ,
The pull-out test structure, wherein the pull-out force loading jack is fitted to the pull-out test nut via the connector . 2. The pull-out test structure according to claim 1, wherein said pull-out test compliant nut is provided with a fitting portion that can be fitted into said connector by rotating said connector. 3. The pull-out test according to claim 1, wherein the pull-out force loading jack is arranged on the angle-adjusting pedestal by abutting the angle-adjusting spherical seat of the pulling-out force loading jack against the receiving portion of the angle-adjusting pedestal. structure. A normal nut for driving a first rock bolt into the natural ground and remaining in the natural ground on the first male screw of the first rock bolt projecting from the driving surface of the natural ground to form a natural ground reinforcement structure. so that the first bearing plate interposed between the driving surface and the normal nut is substantially abutted against the driving surface, and a second lock bolt different from the first lock bolt is screwed in . A lock bolt is driven into the ground, and a pull-out test compatible nut different from the normal nut is screwed into the second male thread of the second lock bolt projecting from the driving surface, and the driving surface is a first step of bringing a second bearing pressure plate , different from the first bearing pressure plate , interposed between and the pull-out test nut, substantially into contact with the driving surface;
A substantially annular angle adjustment pedestal is arranged on the outer periphery of the pull-out test nut, and a pull-out force loading jack, which is a pull cylinder jack that outputs a pulling force by being brought into contact with the second bearing plate, is arranged on the angle adjustment pedestal. At the same time, the connector is fitted to the pull-out test nut having a shape that can be freely fitted to the connector of the pull-out force loading jack, and the pull-out force loading jack moves the pull-out test nut through the connector and the pull-out test nut. a second step of applying a pull-out force to the second rock bolt and performing a pull-out test;
After the pull-out test is completed, the pull-out test nut is left screwed to the second lock bolt so as to constitute a rock reinforcement structure, and the fitting state of the connector is released, and the connection is performed. A construction method for a natural ground reinforcement structure, characterized by comprising a third step of removing the tool and the pull-out force loading jack. The pull-out force loading jack is internally provided with a pressure detection unit for detecting hydraulic pressure input to the pull-out force loading jack and a displacement detection unit for detecting displacement of the second lock bolt to which the pull-out force is applied. Along with, a data transmission processing unit is attached,
In the second step, the data transmission processing unit wirelessly transmits the pressure data acquired from the pressure detection unit or the load data corresponding to the pressure to a data recording device, and the data acquired from the displacement detection unit. 5. The method of constructing a rock reinforcement structure according to claim 4 , wherein the displacement data of the second rock bolt is wirelessly transmitted to the data recording device. A pull-out test apparatus used for the pull-out test structure according to any one of claims 1 to 3 ,
a pressure detection unit that is installed in the pull-out force loading jack and detects the hydraulic pressure input to the pull-out force loading jack;
a displacement detection unit that is installed in the pull-out force loading jack and detects displacement of the second lock bolt loaded with the pull-out force;
a data transmission processing unit attached to the pulling force loading jack;
Equipped with a data recording device,
The data transmission processing unit wirelessly transmits the pressure data acquired from the pressure detection unit or the load data corresponding to the pressure to the data recording device, and the second rock bolt acquired from the displacement detection unit. A pull-out test apparatus characterized by wirelessly transmitting data of the displacement of to the data recording apparatus.

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