JPH05149083A - Buried substance locator in shield excavator - Google Patents

Abstract

(57) [Summary] [Structure] A first coil 11 formed by winding a conductor a plurality of times around the outer periphery of a cutter head 2 rotatably provided in the front part of the shield body 1 and the cutter head 1. A shield excavation comprising a plurality of second coils 12 arranged along the radial direction and an arithmetic processing unit 6 for inputting detection signals from the coils 11 and 12 and calculating the position of the buried object 3. It is the buried object exploration device in the machine. [Effect] Since the position of the metal-made buried object is detected by using a coil, compared to a device using sound waves, radio waves, etc., it is not affected by the soil condition of the front ground and It is possible to reliably and quickly detect only a metallic buried object without requiring complicated signal processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buried object exploration device in a shield machine.

[0002]

2. Description of the Related Art Conventionally, when excavating a tunnel with a shield machine, the distance between both shield machines is increased in order to ensure the safety of excavation work, or when excavating a tunnel in parallel with two shield machines. For the purpose of measurement, etc., sound waves or radio waves were emitted into the ground to check whether there was an obstructive buried object in the ground.

[0003]

However, according to the exploration device using sound waves or radio waves as in the above-mentioned conventional method, the sound waves or radio waves are reflected not only by the buried object which is an obstacle but also by the non-uniformity of the soil. In addition to the occurrence, there are many noise components in these received signals, so that there is a problem that it is difficult to determine whether or not it is an embedded object even if signal processing is performed.

Therefore, an object of the present invention is to provide a buried object exploration device in a shield machine which can solve the above problems.

[0005]

In order to solve the above-mentioned problems, the buried object exploration device in a shield machine according to the present invention is provided with a conductor on the outer peripheral portion of a cutter head rotatably provided on the front portion of a shield body. A plurality of turns of the first coil, a plurality of second coils arranged in the cutter head along the radial direction thereof, a detection signal from each of these coils, and a position of an embedded object. It is composed of an arithmetic processing unit for performing arithmetic operations.

[0006]

According to the above construction, when the shield body approaches the metal-made buried object in front of the natural ground, the first coil detects that and the arithmetic processing unit determines the distance to the buried object. Then, when the shield body further approaches the buried object, the buried objects are detected by the second coils provided in plural numbers in the radial direction, and the position in the vertical plane is also obtained by the arithmetic processing unit.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2, reference numeral 1 denotes a shield main body of a shield machine equipped with an embedded object exploring device 4 capable of exploring an embedded object, particularly a metallic embedded object 3, which is buried in front of the rock, and its front portion. The cutter head 2 for excavation is rotatably provided in the
A detection unit 5 for detecting an embedded object in front of the ground is provided, and a detection signal from the detector 5 is input to the shield body 2 side to calculate the size, type, etc. of the embedded object. An arithmetic processing unit 6 is provided for this purpose.

The detecting section 5 has a first coil (see FIG. 3) 11 having a very large diameter, which is formed by winding a conductor (for example, a copper wire) around the cutter head 2 a plurality of times.
A large number of cutter heads 2 are arranged along a radial direction at predetermined positions, and are composed of a second coil 12 (see FIG. 4) having a very small diameter formed of, for example, a copper wire. The second coil 12 is arranged so that its coil axis direction is parallel to the axis direction of the shield body 1, that is, the front-back direction. The arrows a and b in FIGS. 3 and 4 indicate the traveling direction of the shield machine (the axial direction of the shield body).

Both ends of the first coil 11 and each of the second coils 12 are connected to the input section of the arithmetic processing unit 6 provided on the shield body 2 side. The coils 11 and 12 themselves are covered and protected by a substance other than metal.

Next, a method for exploring buried objects will be described. According to the exploration method in this embodiment, when the shield body 1 approaches the buried object 3 made of metal, which is an obstacle in front of the ground, the first and second coils 1 provided in the cutter head 2 are provided.
It utilizes that the inductance of 1 and 12 changes.

That is, when there is no buried object,
The inductance L of the coil is expressed by the following equation. L = (μ ₀ + χ _m ) × n ² × m × s ... Further, when an embedded object is approached, due to its influence, the inductance L of the coil is expressed by the following equation.

L = (μ ₀ + χ _m + χ _o ) × n ² × m × s ... where L is the inductance of the coil, μ ₀ is the permeability in vacuum, and χ _{m is the} shield machine. Magnetic susceptibility χ _o : Magnetic susceptibility of buried object n: Number of turns of coil per unit length m: Coil length (see FIG. 3) s: Cross-sectional area of coil (see FIG. 3)

From the above equation and equation, the magnetic susceptibility (χ _o ) of the buried object 3 can be obtained. By the way, this magnetic susceptibility (χ
_o ) is related to the material and size of the buried object 3 and the distance (d) to the buried object (for example, the material and size of the buried object such as a water pipe, conduit tube, building foundation, etc. It is known) that the distance (d) to the buried object 3 can be obtained based on this magnetic susceptibility (χ _o ).

Therefore, the first coil 11 provided on the cutter head 2 can detect the distance (d) to the buried object 3 in front of the ground, and a large number of second coils provided in the radial direction. With the coil 12, the radial distance (r) from the center of the shield body 1 can be detected (the radial distance to the second coil having the highest sensitivity is detected), and this radial distance (r) and the maximum sensitivity can be detected. The position of the embedded object 3 with respect to the central axis of the shield body 1 can be obtained from the rotation angle (θ) of the cutter head 2 at which is strongly detected.

That is, the arithmetic processing unit 6 obtains the horizontal distance (d) from the front surface of the cutter head 2 of the shield body 1 to the embedded object 3 and the position within the vertical plane from the central axis of the shield body 1 and surely. The position of the buried object 3 can be known.

The second coil 12 is arranged as follows.
When only the first coil 11 having an extremely large diameter is used, the magnetic flux in the coil cross section becomes uniform, and the buried object 3
This is because it is not possible to determine its position in the vertical plane.

Further, the second coil 12 having a very small diameter
The detectable distance of the first coil 1 is very large.
Although it is shorter than 1, the position of the buried object 3 in the vertical plane is sufficient even if it is detected after the shield machine approaches the buried object 3.

According to such an exploration device, as compared with the case of using sound waves, radio waves, etc., only the metal is assured without being affected by the soil condition of the forward ground and without requiring complicated signal processing. Therefore, not only water pipes and high-voltage conduits that can cause significant damage when cut when excavating with a shield machine, but also the foundations of high-rise buildings that contain many other reinforcing bars, etc. Even a structure can be detected accurately and quickly.

Further, in the structure of the above embodiment, since the coil portion is sealed with a material other than metal, it is suitable for a work environment that requires waterproofness, and is suitable for, for example, a construction site. is there.

Furthermore, in the structure of the above-mentioned embodiment, by combining not only a coil that reacts with a metallic buried object but also a device that uses sound waves, radio waves, etc. that react with various other objects, for example, It is also possible to distinguish between rocks and artifacts.

In the above embodiment, the distance to the buried object and the position in the vertical plane are obtained by detecting the inductance of each coil. For example, the resistance component of the coil, the flowing current, and the current-voltage Phase difference,
A parameter that changes due to the same physical phenomenon such as eddy current loss of an obstacle may be detected.

[0022]

As described above, according to the structure of the present invention, the first coil is provided on the outer peripheral portion of the cutter head of the shield body, and the plurality of second coils are provided along the radial direction of the cutter head. Moreover, since the position of the buried object is determined by the arithmetic processing unit based on the detection signals from both of these coils, the soil condition of the front ground is affected compared to the device using sound waves or radio waves. In addition, it is possible to reliably and quickly detect only the metallic buried object without requiring complicated signal processing.

[Brief description of drawings]

FIG. 1 is a schematic overall side view of a shield machine according to an embodiment of the present invention.

FIG. 2 is a front view of a coil arranged in the cutter head of the shield body in the embodiment.

FIG. 3 is a schematic view showing a first coil in the same example.

FIG. 4 is a schematic view showing a second coil in the same example.

[Explanation of symbols]

 1 shield main body 2 cutter head 3 buried object 4 buried object exploration device 5 detection unit 6 arithmetic processing device 11 first coil 12 second coil

Claims (1)

[Claims] 1. A first coil formed by winding a conductor a plurality of times around an outer peripheral portion of a cutter head rotatably provided on a front portion of a shield body, and a plurality of the coils on the cutter head along a radial direction thereof. A buried object exploration device in a shield machine, comprising: second coils arranged in a line; and a processing device for inputting detection signals from these coils and calculating the position of the buried object.