JPS59142490A - Installing method of seismometer - Google Patents

Abstract

PURPOSE:To raise the measuring accuracy of an earthquake bearing and the installing work efficiency by measuring exactly a direction for fixing a mule shoe by a compass, determining exactly the setting bearing of a seismometer to be installed to this mule shoe, and installing it. CONSTITUTION:A compass 4 is set to the upper part of the mule shoe 5, and when it falls in a well pipe 1 with a rope 6, a recessed groove part 7 of the circumferential side face of the mule shoe 5 is engaged to a key 2 provided on a suitable place of the inside surface of the well pipe 1 and stops. In that place, the bearing of the needle of the compass 4 is photographed, and the mule shoe 5 is drawn upward again. After drawin up, both bodies are fixed so that the installation bearing of the seismometer (a) and the mule shoe 5 for installing it faces in the fixed direction in accordance with the bearing of the key 2. Subsequently, when the seismometer (a) falls down by using the mule shoe 5 as a guide, the recessed groove part 7 is engaged with the key 2, to place the mule shoe 5 on a pedestal 3. In this way, the measuring accuracy of an earthquake bearing and the installing work efficiency are raised.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for installing a seismometer, and particularly to a method for installing a seismometer in deep layers.

To observe seismic waves, it is generally necessary to measure a total of three components: one component in the vertical direction and two components in the horizontal orthogonal direction. degree is extremely important. If the force and direction of the seismometer are not set accurately, it will be impossible to analyze the obtained earthquake records, and if the seismometer is not installed vertically and accurately, the seismometer itself may not work or its sensitivity may be poor. It becomes.

Conventional seismometer installation methods have many deficiencies in these respects and are also disadvantageous in terms of workability. That is,
The main method used in the past was to attach seismometers to rondos and connect multiple rondos together.
This was because it was necessary to build a tower for the Rondo connection work (but also, after the work was completed, the tower was removed, making subsequent maintenance impossible. Due to the installation method, it was difficult to determine the exact orientation of the seismometer.

Therefore, the present invention aims to provide a new method that eliminates the drawbacks of the conventional installation methods, and in particular, to enable installation on the earthquake side in deep layers to be carried out accurately in a predetermined direction. It is.

The working method of the present invention will be explained step by step.

(1) is a valve pipe, and a direction setting key (21) is provided at a suitable place on the inner surface of this valve pipe, and a seismometer (a) is installed at a suitable place below the valve pipe.
The pedestal (on which the mule shoe (5) described later is installed)
3).

First, a compass (4) for measuring direction is attached to the upper part of the mule shoe (5), and it is connected to the valve pipe (
1) Descend inside. During this descent, the Mule Shoe (5
The concave groove (7) formed on a part of the peripheral side of the valve pipe (1) slides while being guided by the tapered left and right edges (7'l
1 K engages and stops at its two most ends. At the same time as this stop, the valve pipe (
1) It is placed on the internal pedestal (31). When this mule shoe (51) is placed in the valve pipe (1), the compass (41
The 0 hand indicates a certain direction. When the camera's automatic shutter is pressed, the direction of the compass needle is photographed and recorded. After photographing in this direction, pull up the mule shoe (51) of the compass key again using the rope (6).

If you look at the photograph taken and recorded after pulling up, you can determine the direction of the key (2) in relation to the compass needle, so after setting the horizontal direction of the seismograph (a) to a constant position, you can find the location of this earthquake. Fix the image so that a) and the mule shoe (5) to which it is attached are facing in a certain direction.At this time, if necessary, in order to make the seismometer (a) vertical, Adjust the joining angle with the mule shoe (51).

After that, the seismometer (a) is lowered using the cable (8) using the mule shoe (51) as a guide.
8) doubles as a rope. Mule shoe (51
acts in the same manner as described above, and stops descending when the uppermost end of its groove (7) engages with the key (21) of the valve pipe (1), and the mule shoe (51 is attached to the valve pipe (1)). It is fixed and placed on the pedestal (3).In addition, the mule shoe (5)
) is placed on the pedestal (3), and the seismometer (a) connected above it with a small gap will descend under its own weight. Then, since the switch (9) is turned on between the mule shoe (51) and the mule shoe (51), it can be confirmed that the mule shoe and the seismometer section are fixed within a predetermined depth of the valve pipe (1) on the ground.

By the way, when the poling hole is drilled with a bend, the valve pipe (11) will also be installed with a slight inclination angle, but after measuring this inclination angle in advance, the mule shoe (earthquake The joining angle of the gauge (a) should be adjusted on the ground, and then the descending installation will be carried out.

Since the present invention uses such a method to install a seismometer, firstly, the direction in which the mule shoe is fixed can be accurately measured using a compass, so it is possible to accurately set the orientation of the seismometer to be attached to the mule shoe. It is now possible to accurately measure the north, south, east, west, and east directions of seismic waves not only vertically but also horizontally, making it possible to measure seismic directions with extremely high accuracy. Second, since this seismometer is installed using wire ropes or cables, installation work, especially in deep observation wells, can be done with just a winch, unlike the traditional Rondo method, which involves building a tower. The effects are extremely large, such as the work efficiency becoming extremely high, and the long-term maintenance costs of the observation well becoming extremely low, making it an economical seismic observation well. be.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention; FIG. 1 is a side sectional view of the observation well during preliminary work, FIG. 2 is a front sectional view of the observation well during main work, and FIG. 3 is a side sectional view of the observation well during preliminary work. FIG. 4 is a side sectional view of the second securing part.

Claims (2)

[Claims] (1) A direction setting key is provided at an appropriate position on the peripheral wall of the valve pipe installed at a predetermined depth, and the mule shoe with the compass attached is first lowered into the valve pipe, and the concave groove of the mule shoe is engaged with the key and stopped. After measuring the direction of the key with the rear compass and pulling up the mule shoe with this compass, set the seismometer in the same direction as the concave groove of the mule shoe, connect the objects in a fixed direction, and then A method for installing a seismograph, comprising descending again into the valve pipe and locking the concave groove of the mule shoe with the key. (2) When the polling hole is inclined, the connection angle between the mule shoe and the seismograph is adjusted in advance to give the seismograph a predetermined verticality. How to install the seismograph described in .