JPH04328411A - Method for measuring buried depth of long body buried in water bottom - Google Patents

Abstract

PURPOSE:To enhance the reliability of the buried distance by accurately measuring the buried distance from the water bottom for a long body which is buried in a water bottom. CONSTITUTION:A nonmagnetic pipe 12 is driven into the bottom from a surveying ship 11 to the depth deeper than the depth of a long body in the vicinity of the long body 10 which is buried in the water bottom such as a sea bottom (b) and a lake bottom. A magnetic sensor 14 is inserted into the nonmagnetic pipe 12 and lowered at a constant speed. A buried depth d1 of the buried long body 10 is detected. The depth d2 of a water bottom d2 is detected with an ultrasonic wave sensor 15. A buried depth d3 of the long body 3 from the water bottom is detected in response to the depth d2 of the detected buried depth d1 of the long body 10 and the depth d2 of detected depth d2 of the water bottom.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is used to measure the depth of buried long objects such as submarine cables and water pipes buried under the bottom surface of the seabed, lakebed, riverbed, etc. Concerning depth measurement method.

0002

[Prior Art] Conventionally, when laying this kind of long body on the water bottom, in order to prevent the long body from being damaged by anchors, fishing gear, etc. It was buried in When investigating whether the elongated body is buried at the correct depth, a diver dives to the bottom of the water where the elongated body is buried, and uses a method such as a dowel from the bottom of the water where the elongated body is buried. The depth at which the long body was buried was being measured from the bottom of the water.

0003

[Problems to be Solved by the Invention] However, in the above measurement method, the buried depth is measured only by the feel of the rod and the long body without visual inspection, so it is possible to confuse the long body with other underwater objects. This may lead to incorrect measurements of burial depth.
The problem was that it lacked reliability. In addition, in recent years, the depth of burial has increased to about 4 to 6 m, and there has been a problem that it has become increasingly difficult to search for long objects with a push rod or the like.

The present invention has been made in view of the above-mentioned problems, and provides a method for measuring the depth of burial of a long body buried under water, which can accurately measure the depth of the long body buried at the bottom of the water. aim at something.

[0005]

[Means for Solving the Problems] In order to solve the above object, the present invention provides a method for measuring the depth of burial of a long body buried at the bottom of the water, which measures the depth of burial of a long body buried at a predetermined position on the bottom of the water. A step of driving a non-magnetic pipe deeper than the depth of the long body in the vicinity of the buried long body, and detecting the buried depth of the long body by inserting and lowering a position detection means into the non-magnetic pipe. a long object detection step; a bottom depth detection step of detecting the depth of the bottom with a bottom depth detection means; a buried depth of the long object detected in the long object detection step; There is provided a method for measuring the depth of burial of an elongate body buried under water, which comprises the step of detecting the depth of burial of the elongate body from the water bottom in accordance with the depth of the water bottom.

[0006]

[Operation] The burial depth of a long body buried at a predetermined position on the water bottom is measured from the depth detected by the position detection means inserted and lowered into a non-magnetic pipe driven nearby and the water bottom depth detection means.

[0007]

Embodiment An embodiment of the present invention will be explained based on the drawings of FIGS. 1 and 2. FIGS. 1 and 2 are diagrams showing an example of an apparatus and its circuit configuration using the buried depth measuring method according to the present invention. In the figure, a long body 10 that is the object to be measured buried at the bottom of the water consists of, for example, a submarine cable, a water pipe, an oil pipe, etc. In the case of a submarine cable, a magnetic steel strip or twisted iron wire is applied to the outer periphery of the cable. In addition, the outer periphery is coated with anti-rust coating such as stainless steel or carbon steel. In addition, for water and oil pipes, the outer periphery of the plastic pipe is reinforced with a magnetic steel strip or twisted steel wire, and the outer periphery is coated with anti-rust coating such as stainless steel or carbon steel.

[0008] In the research vessel 11 that investigates the burial depth of a long body buried under water, a hollow non-magnetic pipe 12 is bored near the buried long body 10 to be measured, and is vertically erected above the water surface. For example, a metal pipe made of stainless steel or brass, or a non-metallic pipe made of FRP is driven therein, and the magnetic sensor 14 is inserted into the non-magnetic pipe 12. Further, a magnetic material 13 is installed on the outer periphery of the non-magnetic pipe 12 at a position in contact with the water surface.

The magnetic sensor 14 descends within the non-magnetic pipe 12 at a constant speed by driving the moving part 16 and outputs signals a and b at the positions of the magnetic body 13 and the buried elongated body 10. The moving section 16 is driven at a constant speed under the speed control of the speed control section 17. The detection unit 18 detects the magnetic body 13 and the buried elongated body 10 using signals a and b generated from the magnetic sensor 14 when the magnetic sensor 14 descends inside the non-magnetic pipe 12, and outputs a detection signal. do.

[0010] Furthermore, the research vessel 11 is equipped with an ultrasonic sensor 15.
is installed and emits ultrasonic waves toward the water bottom, and the detection unit 19 detects the ultrasonic waves reflected from the water bottom to measure the depth of the water bottom. The central processing unit (CPU) 20 has an internal timer circuit, and calculates the time between the detection signals issued by the detection unit 18 when detecting the magnetic body 13 and the buried elongated body 10, and the time input from the speed control unit 17. Determine the depth from the water surface to the buried elongated body 10 based on the velocity information, and
Based on the depth determined above and the depth of the water bottom detected by the detection unit 19, the distance from the water bottom to the buried elongated body 10 is calculated. Then, the calculation result is displayed on the display unit 21 to notify the operator.

That is, as shown in FIG. 1, for example, the time between the detection signals emitted by the detection section 18 is T [minutes], the speed input from the speed control section 17 is V [m/minute], and the detection section If the depth of the water bottom detected in step 19 is d2 [m], and the distance from the water bottom to the buried long body 10 is d3 [m], the depth d1 from the water surface to the buried long body 10 is d1.
=V×T [m], and the distance d3 from the water bottom to the buried long body 10 is
d3 = d1 - d2 [m].

Therefore, in this embodiment, the burial depth of a long body buried at a predetermined position on the bottom of the water can be determined using a magnetic sensor that is inserted and lowered into a non-magnetic pipe that has been driven nearby, and a superstructure installed on a research vessel. Since the measurement is performed using a sonic sensor, the buried distance from the water bottom of the long body buried in the water can be accurately measured and displayed, and the operator can easily recognize the measured buried distance. This makes it possible to improve the reliability of the burial distance.

[0013] In this embodiment, magnetic cables, water pipes, etc. have been explained, but the present invention is not limited to these.
It can also be used to confirm the buried position of non-magnetic cables, etc. In this case, instead of a magnetic sensor, a metal detection sensor that can also detect non-magnetic materials (for example, an electromagnetic wave detection sensor) can be used instead of a magnetic sensor. ), it is possible to detect the depth at which the cable is buried.

[0014]

As explained above, in the present invention, in the method for measuring the depth of burial of a long body buried at a predetermined position on the bottom of the water, a step of driving a non-magnetic pipe deeper than the depth of the elongate body near the body; and a elongate object detection step of inserting and lowering a position detection means into the non-magnetic pipe to detect the buried depth of the elongate body. and a water bottom depth detection step of detecting the water bottom depth with a water bottom depth detection means; and a buried depth of the elongated body detected in the elongate object detection step and the water bottom depth detected in the water bottom depth detection step. Accordingly, since the method includes the step of detecting the buried depth of the elongated body from the water bottom, it is possible to accurately measure the buried depth of the elongated body buried in the water bottom.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of an apparatus using a buried depth measuring method according to the present invention.

FIG. 2 is a diagram showing a circuit configuration of an apparatus using the buried depth measuring method according to the present invention.

[Explanation of symbols]

10 Buried long object (object to be measured) 11 Research vessel 12 Non-magnetic pipe 13 Magnetic material 14 Magnetic sensor 15 Ultrasonic sensor 16　Moving part 17 Speed control section 18, 19 Detection part 20 Central processing unit (CPU) 21 Display section

Claims (1)

[Claims] Claim 1. In a method for measuring the depth of burial of an elongated body buried at a predetermined position on the water bottom, the depth of the elongated body is measured in the vicinity of the buried elongated body. a process of driving a non-magnetic pipe deeper; a process of detecting a long body by inserting and lowering a position detection means into the non-magnetic pipe to detect the buried depth of the long body; and detecting the depth of the water bottom. the long body from the water bottom according to the buried depth of the long body detected in the long body detection step and the depth of the water bottom detected in the water bottom depth detection step; A method for measuring the burial depth of a long body buried underwater, which comprises the step of detecting the burial depth of the body.