JPS5836063Y2 - Jishintan Sayokashinouchi - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an excitation device for seismic exploration.

In general, seismic exploration method (Se15m1c Prospec
tingMethod) is a well-known method for estimating the elastic properties of the ground, underground conditions, etc. by artificially causing earthquakes underground and observing the propagation status of the seismic waves.

Conventionally, in implementing seismic exploration methods, seismic waves have been artificially generated by explosions of gunpowder or the like.

However, the use of gunpowder is not only extremely dangerous, but also destroys the area around the observation point.

However, some of the explosive power of the gunpowder escapes towards the ground, resulting in considerable energy loss.

Furthermore, this tends to cause errors in the setting of the seismic force, which sometimes leads to errors in the measurement results unless the explosive force is set with a considerable margin.

Therefore, the invention of US Pat. No. 3,789,951 was devised.

This is an electro-hydraulic excitation system that is mounted on a vehicle with a drive shaft and generates seismic waves underground.In detail, it consists of four cylinders driven by electro-hydraulic pressure, arranged in pairs of two opposite each other. By driving a weighted piston inserted into the cylinder, pressure is alternately applied to the earth's surface and seismic waves are generated.

The object of the present invention is to obtain a vibrator having a dynamic system with a minimum mass by modifying a conventional vibrator.

However, this invention also has a complicated mechanism and is expensive.

In addition, by driving a piston with a weight inserted in the cylinder, pressure is applied alternately to the ground surface to generate seismic waves, which not only causes energy loss, but also makes the seismic waves obtained by observation extremely complex. The analysis becomes extremely difficult.

Therefore, the present invention was made with the purpose of providing an artificial vibration device that uses safe energy instead of gunpowder and is easy to measure.

In other words, the present invention is characterized by a structure in which a so-called heavy weight of an appropriate weight is used to strike the bottom of a hole at a certain depth underground at an excitation point to generate seismic waves. be.

The weight is suspended manually or by a mechanical device to a suitable height and then allowed to fall freely.

Therefore, according to the present invention, the strength of seismic waves can be freely designed by appropriately setting the weight of the weight and the suspension height, and seismic operations can be performed safely and repeatedly at will. .

Next, the present invention will be explained with reference to embodiments shown in the drawings.

In the figure, reference numeral 1 denotes a support tube, which is inserted into a pilot hole 3 of a certain depth H in the ground dug at an excitation point in the ground 2, and is firmly fixed to the ground by legs 4 above it.

The depth H of the prepared hole 3 is arbitrary depending on the purpose and conditions of the measurement, but the hole diameter is approximately 10 crrL.

The vibration rod 5, which is strong enough not to buckle when struck, is installed in the support tube 1 so as to be movable in the axial direction and to provide a buffer.

That is, the vibration rod 5 is supported in a cushioning manner by bearing plates 6 arranged at appropriate intervals in the support cylinder 1.

The bearing plate 6 is made of a so-called buffering material such as medium-hard rubber or plastic, and supports the vibration rod 5 so that it slides vertically stably and with as little sliding resistance as possible, and also supports vibrations during impact. It is designed to transmit as little energy as possible to the outside and to prevent energy loss.

At the lower end of the vibrating rod 5, an impact plate 8 for hitting the bottom surface 7 of the pilot hole 3, a button, and a weight 9 as necessary are attached.

The method of suspending the vibrating rod 5 with a certain stroke in the vertical direction and allowing it to fall freely is carried out by a mechanical method using a crane or a winch, or by using a boosting mechanism using gears or levers. Manual methods and the like are known.

As an example of the present invention, it is intentionally not shown in the drawings, and only a suggestion that it is carried out by a known method is given.

In any case, in the case of the above-described embodiment according to the present invention, when the vibration rod 5 is suspended at a certain height l by some method and then allowed to fall freely, the impact force generated at that time causes the ground 2 to have a predetermined size. Because the earthquake motion is caused artificially,
By observing the seismic waves at that time, the ground can be investigated.

Also, since the seismic waves obtained are very simple, analysis after observation is easy.

Particularly, according to the present invention, the device is small and simple, so it is convenient to handle and can be easily used in any place, and there is no danger in using it.

Since the conditions are easy to set and the vibration is applied underground, where the geology is relatively uniform, highly accurate seismic exploration can be carried out.

In particular, when used in combination with a stacked seismic recording device, extremely efficient seismic exploration can be carried out.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view illustrating the use of the device according to the present invention. In the figure, 1 is the support tube, 2 is the ground, 3 is the prepared hole, 4 is the leg of the support tube, 5 is the vibration rod, 6 is the bearing plate, 7 is the bottom of the prepared hole, 8 is the impact plate, and 9 is the weight. It is.

Claims (1)

[Scope of utility model registration request] A vibration device for seismic exploration consisting of means for rappelling a vibration rod by arbitrary operation is pressed, and a support tube with its upper leg fixed to the ground is buried at a certain depth underground at the vibration point. A vibration rod is provided in the support tube at appropriate intervals so as to be cushioned by a bearing plate and can slide in the axial direction, and an impact plate and a weight are provided at the lower end of the vibration rod. Vibration device for seismic exploration.