JPH11270280A - Pipe jacking method and surveying instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lay buried pies efficiently with high accuracy by precisely surveying the places and postures of a leader and a buried pipe row efficiently. SOLUTION: A leader 10 and buried pipes 20 connected at the rear of the leader 10 are jacked in a ground E and the pipes 20 are buried gradually into the ground E in the pipe jacking method. The pipe jacking method includes a process, in which a plurality of marker bodies 30 are buried beforehand at intervals along the burying predetermined path T of the pipes 20 in the ground E upper than the place of the burying of the buried pipes 20, a process, in which the marker bodies 30 are detected by detectors 40 installed to the leader 10 and the positional information of the leader 10 is obtained on the basis of detecting information, and a process, in which the jacking direction of the leader 10 is controlled on the basis of positional information, at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propulsion method and a surveying apparatus for leading conductors, and more particularly to a method for laying underground pipes such as sewer pipes, in which a row of buried pipes is installed in the ground without cutting the ground. The present invention relates to a propulsion method for propelling and burying, and an apparatus for measuring the position and posture of a leading conductor arranged at the head of a buried pipe row in such a propulsion method.

[0002]

2. Description of the Related Art The propulsion method does not require excavation of the ground, so that laying of buried pipes can be efficiently performed without interrupting ground traffic or affecting structures on the ground. It is an excellent method in that it is widely applied to the construction work of sewage pipes, gas pipes, electric conduits, etc.

However, with the propulsion method that does not cut the ground, it is not possible to visually check or measure the position and attitude of the leading conductor and the buried pipe row that are propelled in the ground. Therefore, in order to confirm whether the leading conductor and the buried pipe row are being propelled along the previously designed buried pipe laying path, and to correct the deviation from the planned path, propelling in the ground A means for measuring the position and attitude of the leading conductor and the buried pipe row is required.

[0004] In the conventional propulsion method, a method of measuring a leading conductor and a buried pipe row is to measure a laser beam radiated from a departure hole or the like at the rear end of the buried pipe row by using a reflection provided on the leading conductor or the like. There is a so-called laser surveying method in which a survey is performed by capturing with a measuring instrument or a light receiving device. Further, Japanese Patent Application No. 7-40043 (see Japanese Patent Application Laid-Open No. 8-233601), which was filed by the applicant of the present invention, discloses magnetism generated from a magnetic generator such as a magnetic coil mounted on a leading conductor. A technique for detecting the position of a magnetic generator, that is, the position of a leading conductor, by detecting the position of a magnetic field, that is, a detection coil disposed in a magnetic field is disclosed.

[0005]

The above-described laser surveying method uses a laser beam that travels straight, and thus can be easily applied to a linear propulsion method in which a buried pipe row is propelled linearly. There is a problem that it is difficult to apply to a curved propulsion direction that is propelled along. In addition, since the space in which the laser beam travels must be open from the rear end of the buried tube row to the position of the leading conductor, various devices and structures installed inside the leading conductor and the buried tube row are obstructed. In some cases, surveying becomes difficult. Further, when the irradiation distance of the laser beam becomes longer, the error of the survey increases, and it becomes difficult to accurately measure the position of the leading conductor. In order to solve such a drawback, it is conceivable to divide the buried pipe row into a plurality of sections, perform laser surveying for each section, and aggregate the results, but this increases the time and effort of surveying work, There is a problem that survey errors accumulate when totaling the survey results.

In the above method of detecting the magnetic generator provided on the leading conductor by the detection coil on the ground, it is necessary to scan the detection coil back and forth and left and right on the ground to search for the position of the magnetic generator in the ground. Become. To do this on the road,
In the meantime, traffic must be shut off, losing the advantage of the propulsion method that it does not hinder surface traffic. In the propulsion method, the process of propelling the leading conductor and the buried pipe row and the work of connecting a new buried pipe to the tail of the buried pipe row are alternately repeated. It takes time to perform the work. In addition, in order to scan the detection coil on the ground surface, in addition to the detection coil, a large amount of equipment such as an alternating current generator, a power supply device, and a drive device for the detection coil is required. Surveying work is difficult in places where there are obstacles and work is difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for laying a buried pipe with high accuracy and efficiency by accurately and efficiently measuring the positions and postures of a leading conductor and a row of buried pipes in the above-mentioned propulsion method. It is.

[0008]

A propulsion method according to the present invention is a propulsion method in which a leading conductor and a buried pipe connected behind the leading conductor are propelled into the ground and the buried pipe is buried in the ground. And the following steps. A step of burying a plurality of markers at intervals along a planned buried path of the buried pipe in the ground above the buried pipe burying position.

A step of detecting a marker using a detector provided on the leading conductor and obtaining positional information of the leading conductor based on the detected information. The step of controlling the propulsion direction of the conductor based on the position information. Each component requirement will be specifically described. [Buried pipe] A pipe having the same material and structure as those used in the ordinary propulsion method can be used. Fume pipes, steel pipes, concrete pipes, synthetic resin pipes, and composite pipes combining these different materials can also be used. The buried pipe may be either a straight pipe or a curved pipe. In addition to a circular pipe, a pipe with a different diameter such as a rectangular pipe is also used. [Top conductor] A top conductor having a mechanism structure used in a normal propulsion method can be used.

[0010] As means for forming the buried hole by the leading conductor, a digging mechanism comprising a digging bit or the like can be provided at the tip end surface of the leading conductor. The excavated tip conductor can be provided with an earth discharging mechanism for sending the excavated earth and sand backward.
The excavation surface may be provided with a mud feeding mechanism for supplying muddy water or drilling liquid. It is possible to use a consolidation-type front conductor that pushes the front conductor having a cone-shaped tip into the ground to consolidate the ground and propel the front conductor. Lead conductors that perform both excavation and consolidation are also used.

[0011] The leading conductor may be provided with a diverting means such as a diverting jack for changing the propulsion direction of the leading conductor.
It is possible to provide a curved propulsion mechanism for propelling along the curved path by propelling the front conductor with the front and rear portions bent at a predetermined angle. At the rear end of the leading conductor, a connecting means such as a connecting joint capable of connecting the above-mentioned buried pipe is provided. [Signature] The shape and structure of the signage is not particularly limited as long as it can be buried in the ground without hindering traffic and structures on the ground surface and can be detected by a detector.

The structure of the marker differs depending on the detection principle used for the detector, such as electromagnetic, radiation, and ultrasonic waves. Signs are those that actively emit signals to the detector, those that return signals to the detector by receiving signals from the detector, or those that are passively detected without emitting signals to the detector. There is only one thing. A signal generating mechanism such as a battery or a signal generating circuit can be provided to actively emit a signal. However, in the case of considering long-term use with the marker buried, a structure that does not require an energy source inside the marker is preferable.

In order to perform detection using magnetism, the marker may be provided with a magnetic reactant. The magnetic reactant is
It generates some kind of response signal in response to the primary magnetic field generated by the detector. As the magnetic reactant, a magnetic coil combining a conductive coil and a capacitor can be used. When the magnetic coil receives the primary magnetic field, which is an alternating magnetic field, it reacts by generating its own secondary magnetic field. The strength of the secondary magnetic field generated changes according to the strength of the primary magnetic field at the position where the magnetic coil is arranged. The magnetic characteristics can be adjusted by setting the coil material and wire diameter, the coil diameter or the number of turns, the capacitance of the capacitor, and the like, and the detection characteristics of the detector can be changed.

If the outer periphery of the magnetic reactant composed of the magnetic coil is covered with a synthetic resin, ceramic, or the like, even if the marker is buried in the ground, the detection characteristics are unlikely to change due to rust or deterioration. The problem of metal leakage to the ground is unlikely to occur. The marker may be completely buried in the ground, or may be arranged with a part of the marker exposed on the ground surface. If a part of the marker is exposed on the ground, the position of the marker can be visually confirmed or measured. If a part of the sign is exposed on the ground surface, it should be provided with a shape and structure that does not obstruct the traffic and use of the ground surface.

As a method of burying the marker, a method of digging a vertical hole from the ground surface to the ground, inserting the marker into the hole, and backfilling the vertical hole can be adopted. If the vertical hole is not backfilled and only the opening is covered, it becomes easy to collect the used marker. A pipe made of a synthetic resin or the like may penetrate the ground, and a marker may be inserted into the internal space of the pipe. The pipe has a function of accurately maintaining the posture of the sign and protecting the sign.

If the reaction characteristics of the marker are changed according to the purpose and characteristics of the buried pipe, it is possible to accurately detect the buried path of the target buried pipe even in the ground where a plurality of types of buried pipes are mixed. Can be. If the marker is placed in a place as close as possible to the detector installed on the leading conductor, the detection sensitivity is improved. It is buried in the ground above the buried position of the buried pipe so as not to hinder the propulsion of the leading conductor and the buried pipe row.

As long as the intervals between the embedments of the markers are so far as not to hinder the detection of the markers, the narrower the interval, the more precise the position information of the leading conductor can be detected. However, the narrower the interval, the more the number of markers and the more labor for burying the markers. In order to obtain the posture information of the leading conductor, the marker is placed at a depth that can be detected by a detector provided on the leading conductor.

Usually, the marker may be arranged directly above the planned burial path of the buried pipe, but may also be arranged along a position separated from the planned burial path by a predetermined distance. [Detector] The shape and structure of the marker are not particularly limited as long as the position of the marker can be known and the marker can be mounted inside the leading conductor.

The detector may be supported in a fixed state with respect to the leading conductor, may be supported so that its posture such as turning or tilting may be changed, or may be supported movably. Is also good. If the detector is supported movably in the plane direction with respect to the tip conductor, the detector can be moved to specify the position of the marker, or the detector can be placed directly under the marker to remove the marker. The position can be specified reliably. In order to support the detector movably in the plane direction, a plane moving mechanism employed in a general measuring device or the like can be used. In addition, if a position detecting mechanism for detecting the moving position of the detector is provided, the position information of the marker can be obtained from the moving position of the detector.

If the detector is supported rotatably in a horizontal plane and the detection characteristics are different depending on the direction,
The direction of the marker can be known from the strength of the signal received by the detector. If it is necessary to maintain the attitude of the detector relative to the marker in the detection operation of the detector, maintain the attitude of the detector in a horizontal state with respect to the inclination of the leading conductor and rotation around the axis. Means can be provided. In the case of detection using the magnetism, it is preferable that the magnetic field axis of the marker and the magnetic field axis of the detector are oriented in the same direction,
For that purpose, the above-mentioned horizontal maintaining means is effective. [Magnetic Detector] When a magnetic reactant such as a magnetic coil is used as a marker, the detector includes a transmitter for generating a primary magnetic field and a magnetic reactant generated in response to the primary magnetic field.
A receiver for receiving the secondary magnetic field.

The transmitter may include a magnetic coil and a power supply for supplying an alternating current to the magnetic coil. The receiver can include a magnetic coil and a signal processing circuit for detecting an electric signal generated in the magnetic coil. By providing a plurality of receivers in one detector and comparing the received signals of the plurality of receivers, it is possible to efficiently detect the marker. [Detection of marker] If the position of the marker buried at a position accurately measured in advance is detected by the detector, the position of the detector with respect to the marker can be determined based on the position information. Since the position of the detector within the tip conductor is known in advance, the position of the tip conductor with respect to the marker can be determined from the position of the detector with respect to the marker.

When the detector is moved to a position directly below the marker based on the detection signal for the marker, the detector and the conductor for the marker are moved from the movement position of the detector in the leading conductor at that time. Can be known. If the direction of one marker is detected by a detector at a plurality of locations on the leading conductor, the position of the marker can be known as the intersection of the detection directions. In this case, a plurality of detectors may be used, or one detector may be used at a different location to detect a marker.

The posture of the leading conductor can be known based on the position information of the plurality of markers. Specifically, by comparing the buried path of the buried pipe connecting the positions of the plurality of markers with the axis of the leading conductor, the deviation and inclination of the leading conductor with respect to the burying path can be determined. [Propulsion construction] Basically, construction is performed in the same process or work procedure as the normal propulsion method.

At both ends of the construction path, vertical shafts to be a starting shaft and a reaching shaft are excavated. The leading conductor and the buried pipe are sequentially transferred to the starting pit, and thrust is applied to the leading conductor and the row of buried pipes using the main push jack installed in the starting pit, and the leading conductor and the buried pipe are introduced into the ground from the side wall of the starting pit. The buried pipe row is promoted to bury the buried pipe row. If the leading conductor is propelled to the destination pit, the buried pipe row will be buried from the starting pit to the destination pit.

If a normal finishing process such as a connection work with an external buried pipe at each end of the buried pipe row, construction of a manhole in a shaft, and backfilling of earth and sand is performed, the construction of the buried pipe by the propulsion method is completed. . [Control of propulsion direction] During the above-mentioned propulsion construction, a marker is detected by a detector, and the positions and attitudes of the leading conductor and the buried pipe row are measured. Is used to control the propulsion direction of the leading conductor and the buried pipe row.

Specifically, each time one buried pipe is added and the distance of one buried pipe is propelled, the position and posture of the leading conductor can be measured. Even during the propulsion work by the main push jack or the like, the position and orientation of the leading conductor can be measured by detecting the marker.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [Overall Structure] In the embodiment shown in FIGS. 1 and 2, the leading conductor 10 and a buried pipe 20 connected to the rear of the leading conductor 10 are propelled into the ground E, and 2
0 is laid. In the ground E, the buried path T of the buried pipe 20
A plurality of markers 30 are buried at regular intervals along. The embedding position of the marker 30 is set based on precise surveying on the ground surface before the propulsion method is performed.
The burial depth of the marker 30 is determined by
Is set slightly higher than the planned propulsion position.

The marker 30 is made of a molded article of synthetic resin having a thick nail or pile shape as a whole. A coil (not shown) for generating a secondary magnetic field in response to a magnetic field is enclosed therein. Have been. Inside the front conductor 10, detectors 40, 40 are provided at two places before and after. Each detector 40
Generates a magnetic field m having a center line in the vertical direction that penetrates the detector 40, and the magnetic field m acts on the marker 30 to generate a secondary magnetic field from the marker 30. It is received by a receiver provided in the device 40. The position information of the marker 30 with respect to the detector 40 is acquired based on the strength of the received signal. As described above, since the position of the marker 30 is accurately set in advance, the marker 30 with respect to the detector 40 is set.
Conversely, the position of the detector 40 with respect to the marker 30, that is, the absolute position of the detector 40 can be known.

As shown in FIG. 2, a drilling plate 13 having a cutter disposed on the front surface is rotatably mounted on the front conductor 10 by a motor 12, and excavates the ground E on the front surface of the front conductor 10. The leading conductor 10 is propelled. The tip conductor 20
A front part 14 to which the excavation plate 13 and the like are attached and a rear part 16 to which the buried pipe 20 is connected are formed separately so as to be bendable with each other, and the front part 14 and the rear part 16 are provided with a plurality of deflection jacks. It is connected at 18. By adjusting the extension length of the deflection jack 18, the front portion 14 and the rear portion 16 are adjusted.
When the leading conductor 20 is propelled in this state, the propelling direction of the leading conductor 10 changes. [Attachment Structure of Detector] FIGS. 3 and 4 show an attachment structure of the detector 40 to the leading conductor 10. FIG.

As shown in detail in FIG. 4, a disc-shaped detector 40 is supported on a support board 112. Support board 112
Is supported so as to be horizontally movable along the long side direction of the inner frame 110 with respect to the elongated rectangular inner frame 110. As a specific moving mechanism, a ball screw mechanism driven by a servomotor is employed.

The inner frame 110 is horizontally movably supported with respect to the larger rectangular outer frame 100. The horizontal movement direction of the inner frame 110 with respect to the outer frame 100 is the inner frame 1
The direction perpendicular to the direction of movement of the support plate 112 with respect to 10.
As a result, the support board 112, that is, the detector 40 can be moved to an arbitrary position in the plane direction with respect to the outer frame 100.

One side of the outer frame 100 has a spherical shape that can freely rotate both in a vertical plane parallel to the axial direction of the leading conductor 10 and in a vertical plane perpendicular to the axis of the leading conductor 10. Is connected to one end of the support arm 104 via a joint portion 102 having the joint structure described above, and the other end of the support arm 104 is fixed to the inner wall of the leading conductor 10. One end of a support arm 122 is connected to the opposite side of the outer frame 100 near each end of the side via a horizontal attitude adjustment mechanism 120, and the other end of the support arm 122 is connected to the inner wall of the leading conductor 10. It is fixed to.

As shown in detail in FIG. 3, the horizontal posture adjusting mechanism 120 has a ball screw shaft 124
Is rotatably mounted. The upper portion of the ball screw shaft 124 that extends vertically upward is movably screwed and attached to a piece member 126 that can swing in both the axial direction of the leading conductor 10 and the direction perpendicular to the axis with respect to the outer frame 100. .

The operation of the horizontal attitude adjusting mechanism 120 will be described. The tip conductor 10 may rotate or roll around the axis while propelling the ground E. If the leading conductor 10 rotates, the attitude of the detector 40 attached to the leading conductor 10 will be inclined. If the posture of the detector 40 is inclined, the position of the marker 30 cannot be accurately detected. Therefore, the pair of front and rear horizontal posture adjustment mechanisms 120 is operated in accordance with the rotation of the leading conductor 10. Specifically, by adjusting the screw position of the ball screw shaft 124 to the piece member 126 of the outer frame 100 up and down, one side of the outer frame 100 is adjusted up and down to correct the inclination of the outer frame 100, Outer frame 1
00, that is, the detector 40 is kept horizontal.

Further, the leading conductor 10 may be inclined in a direction perpendicular to the rolling, that is, may be pitched such that the axis of the leading conductor 10 is vertically inclined back and forth. At this time, only one of the pair of front and rear horizontal posture adjustment mechanisms 120 is adjusted vertically, or the front and rear horizontal posture adjustment mechanisms 1 are adjusted.
The positions of 20 are adjusted upside down. Thereby, the inclination of the outer frame 100 in the front-rear direction can be adjusted, and the horizontal state can be maintained.

Although not shown, the detector 40 is mounted on the support plate 112.
If the detector 40 is rotatably mounted via a motor or the like, the detector 40 can be rotated in a horizontal plane.
The detector 40 can be directly and rotatably attached to the outer frame 100. [Internal Structure of Detector] As shown in FIG. 5, the detector 40 includes a transmitting coil 42 composed of a conductor coil, and a receiving coil 45 concentric with the transmitting coil 42 and having a smaller outer diameter than the transmitting coil 42. The transmitting coil 42 is connected to an alternating current generator 43 via a switch 44. Receiving coil 4
5 is connected to a signal processing circuit 47 via a switch 46. Switches 44 and 46 are electrically switched at a high speed. The signal processing circuit 47 and the switches 44 and 46 are electrically connected to a control circuit of the entire detector 40 (not shown) or a control circuit of the leading conductor 10.

Marker 30 used with detector 40
Includes a magnetic coil circuit including a coil 32 serving as a magnetic reactant and a capacitor 34 therein. Marker 3
The zero coil 32 and the transmitting coil 42 and the receiving coil 45 of the detector 40 are arranged such that their central axes are parallel to each other. For the ground E, the coils 32, 42,
45 are arranged so that the central axis thereof faces the vertical direction of the ground E.

The operation of the detector 40 having such a structure will be described. When the switch 44 of the transmitting coil 42 is turned on,
An alternating current flows through the transmitting coil 42 to generate a primary magnetic field. A secondary magnetic field corresponding to the strength of the primary magnetic field is generated in the coil 32 of the marker 30 placed in the magnetic field of the primary magnetic field due to an electromagnetic resonance phenomenon. When the switch 44 of the transmitting coil 42 is turned off and the switch 46 of the receiving coil 45 is turned on, a received signal flows through the receiving coil 45 by the action of the secondary magnetic field generated by the coil 32 of the marker 30, and the signal processing circuit 47 Is detected. When the switches 44 and 46 are switched at a high speed, the receiving coil 45 is not affected by the primary magnetic field generated by the transmitting coil 42 and the marker 3
Only the secondary magnetic field generated by the zero coil 32 can be accurately received by the receiving coil 45. [Detection of marker: case of single receiving coil] It is assumed that the detector 40 and the marker 30 are separated from each other in the plane direction as shown in FIG. The primary magnetic field generated by the transmitting coil 42 of detector 40, the coil 32 of the label 30 to generate a second magnetic field, when receiving the second-order magnetic field receiving coil 45, the received signal S ₁ is obtained.

When the detector 40 is moved in a direction intersecting a straight line connecting the detector 40 and the marker 30, the detector 4
Since the distance from 0 to the marker 30 varies, the received signal S ₁ varies. The reception signal S ₁ indicates a local maximum when the detector 40 comes closest to the marker 30 on the moving route.
Although not shown, the received signals S ₁ when the detector 40 is disposed beneath the label 30 indicates the maximum strength. Label 30 in the direction perpendicular to the moving direction from the point indicated the strength of the maxima of the received signal S ₁ is can be seen that there. [Detection of Marking Object: Case of Two Receiving Coils] As shown in FIG. 7, a detector 40 is provided with one transmitting coil 42 and two receiving coils 45a and 45b whose characteristics are matched with each other. Be prepared. The receiving coils 45a and 45b are arranged at left and right target positions with respect to the planar shape of the transmitting coil 42.

<Detection of Direction of Marker> As shown in FIG. 7A, when the detector 40 is moved in a linear direction, the received signals Sa and Sb of the receiving coils 45a and 45b change.
The difference Sab between the two received signals Sa and Sb also changes. The position where both received signals Sa and Sb are exactly the same (signal difference S
At the position where ab becomes 0), the distance from the receiving coil 45a to the marker 30 is the same as the distance from the receiving coil 45b to the marker 30. This state means that the marker 30 exists on the vertical bisector C of the line connecting the centers of the left and right receiving coils 45a and 45b.

As described above, the two receiving coils 45a, 4a
In the detector 40 provided with 5b, the direction of the marker 30 with respect to the detector 40 can be easily known by moving the detector 40 in a linear direction. Next, as shown in FIG. 7 (B), when the same detector 40 is horizontally rotated at the same position, the received signals Sa and S shown in the graph (I) are obtained.
b and the signal difference Sab are obtained. In the graph (I), the horizontal axis represents the rotation angle.

The reception signal Sa of one reception coil 45a
In a state where the difference between the received signal Sb of the other receiving coil 45b and the received signal Sb is the largest, in other words, at a position where the signal difference Sab has the maximum value, on the extension line C of the line connecting the centers of the receiving coils 45a and 45b. Means that the marker 30 exists. At this time, the marker 30 is present in the extension direction of the receiving coil 45a indicating the larger received signal Sa.

The above-mentioned pair of receiving coils 45a,
State (A) in which received signals Sa and Sb of 45b are the same.
And the reception signals Sa of the pair of reception coils 45a and 45b,
The state (B) in which the difference Sab of Sb is maximum means that the detector 4
0 is just rotated 90 °. Therefore, the detector 40 is moved in the linear direction, and the pair of receiving coils 45 are moved.
If the detector 40 is rotated by 90 ° at the position ((A) state) where the received signals Sa and Sb of the a and 45b are matched ((B) state), the reception on the side showing the large received signal Sa or Sb will occur. It can be seen that the marker 30 exists in the extension direction of the coil 45a or 45b.

<Determination of Position of Marker> When the direction of the marker 30 with respect to the detector 40 is determined in the previous operation, the detector 40 is then moved in a direction approaching the marker 30. The changes in the received signals Sa and Sb at that time are shown in the graph (I
Shown in I). When the detector 40 is separated from the marker 30, the signal difference Sab becomes constant. When the detector 40 comes under the marker 30, the signal difference Sab becomes smaller and the detector 4
If 0 is disposed directly below the marker 30, the marker 30 is located between the pair of receiving coils 45a and 45b,
The received signals Sa and Sb become the same, and the signal difference Sab disappears. Conversely, the detector 4 is located at a position where the signal difference Sab becomes zero.
By moving 0, the position immediately below the marker 30 can be determined.

In order to easily obtain the signal difference Sab between the pair of receiving coils 45a and 45b, the receiving coils 45a and 45b
If the polarity of the coil terminal 5b is reversed, the signal difference Sab can be directly obtained as an output. [Detection of marker: Case of Three Receiving Coils] As shown in FIG. 8, one detector 40 has three receiving coils 45a,
45b and 45c are arranged.

In the same manner as in the case where the number of the receiving coils is two, the detector 40 is linearly moved or rotated, and as shown in the graph (I), the three receiving coils 45 are formed.
The received signals Sa and Sb of any two of the receiving coils 45a and 45b among the signals a, 45b, and 45c are matched.
In this state, the marker 3 is placed on an extension C of a line connecting the centers of the two receiving coils 45a and 45b from the center of the detector 40.
0 exists.

At this time, the remaining one receiving coil 45c
, The direction of the marker 30 is also known. That is, if the reception signal Sc is smaller than the other reception signals Sa and Sb, the marker 30 exists in a direction on the extension line C on the opposite side to the reception coil 45c. Received signals Sa, S
If the received signal Sc is larger than b, the marker 30 exists in the direction of the receiving coil 45c.

When the direction of the marker 30 is known, the detector 40 is moved in the direction of the marker 30 as described above. As shown in the graph (II), the received signals Sa and Sb always coincide, and the received signal difference Sabc between the received signals Sa and Sb and the received signal Sc is determined until the detector 40 approaches the position of the marker 30. Is constant. When the detector 40 comes to the position of the marker 30, the signal difference Sabc becomes smaller, and when the detector 40 becomes right below the marker 30, the marker 30 is arranged at the center of the three receiving coils Sa to Sc. Therefore, all the received signals Sa
Sc match, and the signal difference Sabc becomes zero.

Accordingly, the three receiving coils 45a to 45a-4
In the detector 40 provided with the marker 5c, the identification of the direction of the marker 30 by the linear movement or rotation of the detector
The operation up to the specification of the position can be easily performed. [Positioning of marker on plane] As shown in FIG.
A method for specifying the position of the marker 30 on a rectangular plane surrounded by XZY points will be described. In this case, the detector 40
May have a structure having one receiving coil 45 shown in FIG.

While moving the detector 40 along one of the diagonal lines OZ, the position P at which the received signal S ₁ becomes maximum is obtained.
Ask for. Next, the detector 40 is moved from the point P in a direction orthogonal to the diagonal line OZ. At this time, the received signal S ₁ is moved in the direction of increasing. The position where the received signal S ₁ shows the maximum value is the position directly below the marker 30. The above-described movement control of the detector 40, detection work, processing of received signals, and the like can be automatically performed by programming the computer. [Method of Using Two Detectors] The position of one marker 30 is determined by using two detectors 40 each having one transmitting coil 42 and a pair of receiving coils 45a and 45b shown in FIG. To detect.

As shown in FIG. 10, two detectors 40
A and 40B are arranged before and after the leading conductor 10. Each of the detectors 40A and 40B is mounted so as to be horizontally rotatable, but may not be able to move linearly in the horizontal direction. By rotating each of the detectors 40A and 40B, a direction in which the reception signals Sa and Sb of the pair of reception coils 45a and 45b match is detected, and the rotation angle at that time is obtained.

Positions A and B of front and rear detectors 40A and 40B
With respect to a straight line connecting the center lines of the pair of receiving coils 45a and 45b in the detectors 40A and 40B.
₁ and θ ₂ are obtained. In the triangle formed by the positions A and B of the detector 40 and the position Q of the marker 30, a straight line A
The distance L of B is obtained in advance. From the distance L of the straight line AB and the data of the angles QAB = θ ₁ and QBA = θ ₂ , the triangle AB
Q is specified, and the position of the marker Q is specified.

Therefore, in the above method, the position of the marker 30 can be specified simply by rotating the two detectors 40A and 40B while keeping their positions fixed, and the position of the marker 30 can be specified quickly and easily. I can do it. [Detection of Post Conductor Posture] The embodiment shown in FIG. 11 detects the inclination of the posture of the front conductor 10 with respect to the buried path T, or the deviation between the direction of the buried path T and the propulsion direction of the front conductor 10.

Two markers 3 arranged on the buried path T
The positions of 0 and 30 are detected by any of the detection methods described above. Detectors 40 arranged at two places before and after the tip conductor 10,
The front and rear markers 30 and 30 may be detected at 40, respectively, or the two detectors 40 and 40 may cooperate to detect the position of the front marker 30 and then return to the two detectors 4 again.
Using 0 and 40, the position of the rear marker 30 can also be detected.

The displacement of the leading conductor 10 in the axial direction with respect to the straight line connecting the front and rear markers 30 indicates the inclination of the posture of the leading conductor 10. The direction in which the straight line extending between the markers 30 is extended is the direction in which the leading conductor 10 should be propelled.
Is the direction in which the vehicle is actually propelled, and a deviation between the two is required. If the propulsion direction is corrected by operating a deflection jack or the like provided on the front conductor 10 so that the propulsion direction of the front conductor 10 approaches the buried path T as much as possible, the displacement of the propulsion direction of the front conductor 10 with respect to the buried path T can be improved. Can be eliminated. [Embedding Method of Marker] The embodiment shown in FIG.

As shown in FIG. 12A, a vertical hole H is dug in the ground E. A pile-shaped marker 30 is driven into the bottom of the hole H. As shown in FIG. 12B, if the soil is buried in the hole H, the marker 30 can be buried at a position at a certain depth in the ground E. The embodiment shown in FIG. 13 is a method different from the above embodiment. As shown in FIG.
Then, a synthetic resin pipe 34 is driven. The marker 30 is suspended by a wire 36 and inserted into the pipe 34, and lowered to the bottom of the pipe 34.

As shown in FIG. 13B, a lid 38 is attached to the upper end of the pipe 34. The wire 36 hanging the marker 30 is fixed to the lid 38. This makes it possible to remove the lid 38 and collect the marker 30 at a later date.
In the state shown in FIG. 13A, the soil can be buried inside the pipe 34. The marker 30 may be fixed in the pipe 34 before being driven into the ground E, and the marker 30 may be buried at the same time as the driving of the pipe 34.

[0058]

According to the propulsion method and surveying device according to the present invention, a marker provided in the conductor in advance is used to detect a marker buried in the ground along a planned buried route,
Since the deviation of the position and attitude of the leading conductor from the buried route is known and the propulsion direction of the leading conductor is controlled based on the result, the construction accuracy of the buried pipe is remarkably improved. In particular, efficient work can be performed without obstructing ground surface traffic and structures, and without hindering propulsion work.

[Brief description of the drawings]

FIG. 1 is a perspective sectional view showing an embodiment of the present invention and showing a construction state of a propulsion method.

FIG. 2 is a vertical sectional view of a construction state.

FIG. 3 is a cross-sectional view in a direction orthogonal to an axis of a tip conductor representing a mounting structure of the detector.

FIG. 4 is a plan view of the detector.

FIG. 5 is a schematic structural diagram showing an internal structure of the detector.

FIG. 6 is an explanatory diagram showing a detection operation of the detector.

FIG. 7 is an explanatory diagram showing another embodiment of the detection operation.

FIG. 8 is an explanatory diagram showing another embodiment of the detection operation.

FIG. 9 is an explanatory diagram showing another embodiment of the detection operation.

FIG. 10 is an explanatory diagram showing another embodiment of the detection operation.

FIG. 11 is an explanatory diagram showing another embodiment of the detection operation.

FIG. 12 is a cross-sectional view illustrating a process of embedding a marker.

FIG. 13 is a cross-sectional view illustrating another embodiment of the embedding step of the marker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Lead conductor 20 Buried pipe 30 Marker 40, 40A, 40B Detector 42 Transmitting coil 45, 45a-45c Receiving coil E Ground

Claims (9)

[Claims] 1. A propulsion method in which a buried pipe is buried in the ground by propelling a buried pipe connected to the back of the leading conductor and the back conductor into the ground, the buried pipe being located above a buried position of the buried pipe. Burying a plurality of markers in the ground at intervals along a route to be buried in the buried pipe; detecting the markers with a detector provided on the leading conductor, based on the detection information. And a step of controlling the propulsion direction of the leading conductor based on the positional information. 2. The method according to claim 1, wherein the step of embedding the marker uses a marker having a magnetic reactant that generates a secondary magnetic field when a primary magnetic field acts thereon as the marker, and the step of obtaining the position information includes: 2. The propulsion according to claim 1, wherein a primary magnetic field is generated from the detector, and a secondary magnetic field generated by the magnetic reactant in response to the primary magnetic field is received by the detector to detect the marker. Construction method. 3. The propulsion method according to claim 1, wherein the step of obtaining the position information detects the marker from an intensity distribution of a received secondary magnetic field when the detector is moved or its posture is changed. . 4. The method according to claim 1, wherein the step of obtaining the position information includes detecting the marker by moving the detector to a position directly below the marker based on the intensity distribution of the secondary magnetic field received by the detector. 1 to
3. The propulsion method according to any one of 3. 5. The propulsion method according to claim 1, wherein the step of obtaining the position information obtains posture information of the leading conductor from detection information of a plurality of markers. 6. The propulsion method according to claim 1, wherein the step of obtaining the position information detects a direction of one marker by a detector from a plurality of positions of the leading conductor. 7. The surveying method according to claim 1, wherein the surveying device is used in the step of obtaining the position information and is installed in the tip conductor, and detects the marker. A surveying apparatus comprising: a plane moving unit that moves the detector in a plane direction; and a level maintaining unit that adjusts a tilt of the plane moving unit to maintain a horizontal state. 8. The detector comprises a transmitter for generating a primary magnetic field, which is an alternating magnetic field, and a receiver for receiving a secondary magnetic field generated by the magnetic reactant in response to the primary magnetic field. The surveying device according to claim 7. 9. The surveying device according to claim 8, wherein said detector comprises a plurality of said receivers.