JP2000284061A - Buried object-prospecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily detecting metallic and non-metallic buried objects without increasing working man-hours. SOLUTION: In a method for prospecting a non-metallic buried object in a section where piping is laid, a first process where starting and arrival shafts 1 and 2 are provided at both the ends of the laying section, and a rotation rod 4 being delivered from a ground-installation-type propulsion machine 3 is used for bore a drilling bole, and a second process where, after the first process, a detector 10 for detecting a pipeline being already laid near the drilling hole is inserted into the boring hole for moving. In the second process, an air percussion using an air hammer is interlocked to the rotation rod 4, at the same time, a receiver that receives the reflection wave of impact sound being generated from the air percussion via a buffer material being arranged at a part to the air percussion is connected, and the reflection state of the impact sound being generated from the air percussion is discriminated via the receiver for detecting a buried object.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for exploring a buried object, and more particularly, to a method for exploring an underground buried object for a non-metallic pipeline.

[0002]

2. Description of the Related Art When newly laying a pipeline such as a gas pipe, it is necessary to investigate whether or not an existing buried pipeline exists near the laying section. As one of the exploration methods, there is a non-contact exploration method, in which an electromagnetic wave or a high-frequency signal is emitted on the surface of the laid section,
A method of detecting the state of reflection to detect the presence or absence of a buried pipeline is employed. As a specific example of the above exploration method, a sensor capable of transmitting and receiving an electromagnetic wave or a high-frequency magnetic field or the like is provided on a movable body, and the reflection state is identified by an image monitor while moving the movable body in a section where the movable body is to be laid. A method of detecting the presence / absence (for example, see Japanese Patent Application Laid-Open No. 62-27347)
No. 6) or, alternatively, a pair of standing holes are formed at a predetermined interval and a predetermined depth in the laying section, and the transmitter and the receiver are sequentially lowered in each hole, so that the electromagnetic wave transmitted from the transmitter or There is a method of checking for the presence or absence of an existing buried pipe by checking the attenuation rate of a high-frequency signal by a receiver (for example, Japanese Patent Application Laid-Open No. 623-290985). As a modification of the example disclosed in the latter publication, there is an example in which a transmitter and a receiver are arranged in a single hole.

[0003]

In recent years, instead of metal pipes which are liable to be damaged or cracked in the event of a disaster such as an earthquake, resin pipes such as polyethylene pipes having a certain degree of flexibility have been used. In the case of such a resin pipeline, it is difficult to detect a buried pipeline using electromagnetic waves. Conventionally, as a detection method targeting a resin pipeline, an antenna equipped with a transmitter is arranged in advance on an existing resin buried pipe, and a receiver is disposed on the ground surface, and the electromagnetic wave transmitted from the transmitter is There has been proposed a configuration in which a position of a buried pipeline is determined by receiving a signal by a receiver (for example, Japanese Patent Application Laid-Open No. 4-36688).
However, the technique disclosed in the above publication is based only on the premise that the existence of a buried pipeline must be known in advance, and can be applied as a method for detecting the presence of this buried pipeline. It cannot be done. In addition, in the technology disclosed in the above publication, a shaft must be formed to expose the end of the buried pipeline known to exist in advance.
Depending on the depth, there is a possibility that the number of work steps is increased.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a buried object in the prior art, particularly in a method for detecting a buried object for a non-metallic buried conduit, and to easily and without increasing the number of working steps. An object of the present invention is to provide a method capable of detecting a nonmetallic buried object.

[0005]

In order to achieve this object, the present invention relates to a method for exploring a non-metallic buried object in a section where a pipe is laid, comprising a starting shaft and a reaching shaft at both ends of the laying section. And drilling a boring hole using a rotating rod fed from a ground-mounted propulsion machine.
And a second step of, after the first step, inserting and moving a detector for detecting an existing pipeline located in the vicinity of the borehole into the borehole, and moving the vibration source in the second step. While connecting the body to the rotating rod,
A receiver for receiving a reflected wave of a sound emitted from the vibration source body via a buffer material disposed between the vibration source body is provided in series, and the reflection state of the sound emitted from the vibration source body is determined by the receiver. And detecting a buried object through the interface. As the vibration sound source, an air percussion using an air hammer (Claim 3), a device using a rotary driving force of a hydraulic motor or the like (Claim 4), and a speaker having a waterproof structure (Claim 5) Is used.

Further, the present invention is characterized in that a cushioning material is interposed between the vibration sound source and the receiver. In the receiver, the reflection state is detected except for the impact sound emitted from the vibration sound source.

[0007]

According to the first, third to fifth aspects of the present invention, a detector is inserted into the borehole formed in the first step without excavation other than the borehole, and the detector is moved while moving. The presence or absence of a nonmetallic buried object can be detected by determining the reflection state of the sound wave emitted from the vibration sound source.

[0008] According to the second and sixth aspects of the present invention, it is possible to accurately discriminate whether or not the sound wave incident on the receiver is from a buried object.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is a view for explaining a method of laying a pipe by non-cutting and digging, to which a method for exploring a buried object according to an embodiment of the present invention is applied, and FIG. 1 shows a first step of the laying method. In FIG. 1, a first starting shaft 1 and a reaching shaft 2 are provided in the route of laying the underground pipe, and a road-mounted propulsion device 3 is disposed on the ground on the first starting shaft 1 side. The propulsion device 3 is provided with a guide drill unit 3a that acts to feed out the rotary propulsion rod 4 with a required pushing force and pull it back with a required pulling force, as in the related art. In addition, a power unit truck 3b serving as a power source is disposed near the guide drill unit 3a.

In the first step shown in FIG. 1, first, a drill head 5 is attached to a tip of a rod 4 fed from the propulsion device 3. Then, by operating the propulsion device 3, the tip of the rod 4 to which the drill head 5 is attached is made to enter the ground through a penetration hole 6 provided on the ground. Next, by continuously operating the propulsion device 3, the rod 4 is rotationally propelled under the target line reaching the reaching shaft 2 by traversing the first starting shaft 1 by the pushing force of the propulsion device 3. Thus, a boring hole (length: 100 m) for drawing in the pipe is formed. In addition,
At this time, bentonite muddy water is jet-jetted from the tip of the drill head 5, and it is possible to excavate while cutting down the soil by the water flow.

When the rod 4 is propelled, a signal 7 from a transmitter (not shown) incorporated in the drill head 5 is detected by a detector 8 on the ground to grasp the position of the tip of the boring hole. The distal end of the rod 4 is sequentially corrected by remote control from the ground so as to avoid obstacles such as other buried objects.

Next, in a second step shown in FIG. 2, the drill head 5 is removed on the side of the reaching shaft 2 and a detector 10 is attached to the tip of the rod 4 instead. Detector 10
Includes a vibration sound source 11 and a sound wave receiver 14 opposed to the vibration sound source 11 with a buffer material 13 absorbing the vibration from the vibration sound source 11 interposed therebetween. As shown in FIG. 3, an air percussion connected to the rotating rod 4 is used as the vibration sound source. The air percussion is driven by the air hammer 12 to generate an impact sound. A wire 15 used to pull the rotating rod 4 back toward the arrival shaft 2 again is connected to the acoustic wave receiver 14. In FIG. 3, reference numeral 12 </ b> A indicates an air supply / discharge hose that communicates with the air hammer 12.

An air percussion (hereinafter referred to as a vibration sound source 11 for convenience) has a perforated member used for excavation work and the like, and an air hammer 12.
It is a device that can excavate by hitting the perforated member. The air percussion 11 can emit an impact sound when the perforated member is beaten by the air hammer 12, and the impact sound propagates around the boring hole. The sound wave receiver 14 includes a plurality of microphones installed in the circumferential direction of the boring hole,
The installation angle is registered in a control device (not shown) in advance.

In the detector 10, the air percussion 1
1 is to detect a reflected sound at a timing capable of removing an impact sound generated when the device 1 operates.
In addition, a threshold for distinguishing between a reflected sound from a reflector other than the buried conduit and a reflected sound from the buried conduit in the peripheral portion is set and detected.

The detector 10 connected to the rotating rod 4 is
The stop is repeated at predetermined intervals while the rotating rod 4 is pulled back toward the starting shaft 1 by the propulsion device 3, and the air percussion 11 emits an impact sound at the stop position. The detector 10 detects the reflection state of the impact sound wave from the air percussion 11, and detects the presence of the buried conduit when the reflection sound at the time except when the impact sound is generated is equal to or more than the threshold value. The position of the buried conduit is specified by the reflection time at that time and the angle of the received microphone.

When the detector 10 reaches the starting shaft 1, the detection result in the moving process up to that time is output from the control device. The detector 10 that has reached the starting shaft 1 is removed from the rotating rod 4, the wire 15 is connected to the rotating rod 4, and the rotating rod 4 is pulled back toward the reaching shaft 2. The rotating rod 4 returned to the arrival shaft 2 is provided with an expanding reamer for expanding the diameter of the boring hole, and is again pulled back toward the starting shaft 1 by the propulsion device 3.

In the above embodiment, the air percussion 11 operated by the air hammer 12 is used. However, instead of this, the following configuration can be used. That is, a rotary drive such as a hydraulic motor is used. According to this configuration, the vibration frequency can be changed by being able to emit continuous sound and controlling the number of rotations.
In such a configuration, the search range is reduced as the frequency increases, but the resolution is improved. For example, when searching for a dangerous buried object, the position of the search target can be accurately determined. .

Further, a speaker having a waterproof structure can be used as the vibration sound source. Also in this case, since the vibration frequency can be changed, the same operation as the above-described rotary driving body can be obtained.

[0019]

As is apparent from the above embodiments, according to the first, third to fifth aspects of the present invention, excavation other than the boring hole is performed for the boring hole formed in the first step. It is possible to detect the presence or absence of a non-metallic buried object by inserting a detector and determining the reflection state of the impact sound generated by air percussion while moving the detector. In particular, according to the fourth and fifth aspects of the present invention, since the vibration frequency can be changed, it is possible to improve the resolution and perform an accurate search, and it is possible to improve the search accuracy.

According to the second and sixth aspects of the present invention, it is possible to accurately discriminate whether a sound wave incident on a receiver is from a buried object. As a result, a search with less occurrence of erroneous determination becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a first step of a non-cutting pipe laying method to which a buried object search method according to an embodiment of the present invention is applied.

FIG. 2 is a schematic diagram for explaining a second step executed following the first step shown in FIG. 1;

FIG. 3 is a schematic diagram for explaining a configuration of a detector used in a second step shown in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Starting shaft 2 Arriving shaft 3 Propulsion device 4 Rotating rod 10 Detector 11 Air percussion 12 Air hammer 14 Sound wave receiver

Claims (6)

[Claims] 1. A method for exploring a buried object in a section where a pipe is laid, comprising: a starting shaft and a reaching shaft at both ends of the laying section; A first step of digging a hole, and after the first step, a second step of inserting and moving a detector for detecting an existing pipeline located near the boring hole into the boring hole, In the two steps, a vibration sound source is connected to the rotating rod, and a receiver for receiving a reflected wave of a sound emitted from the vibration sound source via a buffer material disposed between the vibration sound source and the vibration sound source is provided in series. A method for detecting a buried object by determining a reflection state of a sound emitted from a vibration sound source through the receiver. 2. The method for detecting a buried object according to claim 1, further comprising a configuration in which the cushioning material is interposed between the vibration sound source and the receiver. 3. The method according to claim 1, wherein the vibration sound source is an air percussion using an air hammer. 4. The method for detecting a buried pipe according to claim 1, wherein said vibration sound source uses a rotary motor such as a hydraulic motor. 5. The method according to claim 1, wherein a speaker having a waterproof structure is used as the vibration sound source. 6. The method for detecting a buried object according to claim 1, wherein the detector detects a reflection state except for an impact sound emitted from the air percussion.