JPH0729476Y2 - Soil backfill hardness tester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a backfill hardness tester for soil excavated when installing or repairing a telephone, gas, water, etc.

<Prior Art> Normally, when the soil excavated at the time of construction of telephone, gas, water, etc. is backfilled on the road as described above, the backfilled soil is restored to a certain standard hardness. Is obligatory.

Therefore, as the means for measuring the hardness of the soil that has been backfilled so far, there are adopted many means such as a simple type and a method of separately analyzing the data collected at the site in a data processing room.

For example, as described in the document “Reuse of excavated soil” on December 5, 1984, published by Sankaido, pages 66 to 74, cone penetration test, earthwork type penetration test, ball drop test, etc. is there.

That is, in the cone penetration test, a penetration rod having a cone having an opening angle of 30 ° is made to penetrate into the ground by pushing through a proving ring by hand, and the deformation strain of the proving ring caused by the penetration resistance at that time. The backfill hardness of the ground is determined by reading the size of the data with a dial gauge and processing the data.

Further, in the earth-penetration type penetration test, a penetration rod having a cone having an opening angle of 60 ° is erected and retained on the backfill ground, and a weight fitted on the penetration rod has a constant height on the penetration rod. The hardness of the ground is to be measured by recording the number of repeated drops from the position where the cone repeatedly falls until the cone penetrates into a certain depth in the soil.

Furthermore, in the sphere drop test, a weight with a certain height is naturally dropped from a specified height, and the hardness of the ground is calculated from the size of the depression hole caused by the impact of the sphere coming into contact with the ground. It's something I got to get.

In addition, there is a means for collecting data using a large-scale device which is more complicated and deviceized by the above means. (Refer to the above-mentioned document) <Problems to be solved by the device> However, while the above three formers are both easy and easy to install in the field and easy to carry, operate, etc. In addition, there is a drawback in that the large-sized device is limited in installation place, is not versatile in adjustment for installation, and the like.

Therefore, in the present invention, it is more convenient than the above-mentioned conventional testing device, and the preparation and measurement operation are easy, and
It is an object of the present invention to provide an apparatus capable of quickly obtaining highly accurate data.

<Means for solving the problem> A cylindrical hammer guide that can be held upright, a hammer that can fall naturally in the hammer guide and that has an impact sensor housed inside, and a hammer sensor that is connected to the impact sensor in the hammer And a detection arithmetic unit.

<Operation> The hammer guide is held upright on the backfilled ground to be measured, the hammer in the hammer guide is pulled up to a certain height, and the hammer is naturally dropped. Then, the magnitude of the impact force when the hammer comes into contact with the ground is electrically detected by the impact sensor, the data is immediately analyzed by the detection calculation device, and the hardness at that point is determined and displayed.

<Embodiment> Hereinafter, the present invention will be described in detail with reference to an embodiment shown in the drawings. A hollow hammer guide 1 having a constant height.
A flange-shaped flooring plate 3 is fixed to the outer periphery of the lower end of the hammer by welding or other screws so that the hammer guide 1 can stand vertically on the backfilled ground.
Inside, a hammer support 5 is fixed to the lower end of a hollow rod 6 projecting an appropriate length from the upper end of the hammer guide 1, and the hammering surface is flattened at the lower end of the support 5 as shown in the drawing. A hammer 2 is provided in series, an impact sensor 4 (may be a load cell) is interposed between the hammer 2 and the hammer support 5, and a handle 9 is provided in an orthogonal connection to the upper end of the rod 6 so that 2 can be pulled up, and at the same time from the impact sensor 4 to the rod 6 and the grip rod 9.
The coaxial cable 7 is pulled out through the inside, and the detection arithmetic unit 11 is connected to the other end.

In the figure, reference numeral 8 is a ferrule attached to the upper end of the hammer guide 1, and 10 is a transport hanger fitted in a substantially middle portion of the hammer guide 1.

Further, in the above structure, the weight of the hammer 2, the size of the surface of the hammer 2 contacting with the ground, the falling stroke of the hammer 2 and the like are predetermined, and when the hammer 2 naturally falls, the hammer 2 There is no contact between the outside and the inner wall of the hammer guide 1, and a small gap is formed so that the hammer guide 1 can fall smoothly.

The present invention is as described above. The hammer guide 1 is self-supported by the landing plate 3 on the backfill ground after excavation for underground burial work of telephones, installation of water, gas, etc. at passages, etc. After setting the power supply of the detection arithmetic unit 11 and pulling it up to a certain height with the handle 9 of the hammer 2, the hand of the handle 9 is released, so that the hammer 2 is naturally dropped in the guide 1. Then, the impact force when the hammer 2 contacts the ground is captured by the impact sensor 4 and displayed on the detection / calculation device 11 via the coaxial cable 7.

In this way, the impact force received by the impact sensor 4 is used because it changes depending on the hardness of the ground.

<Effect of device> Since the device of the present invention is configured as described above, the measurement time is significantly shortened (about 10 seconds), and it is possible to measure at many points, making the average hardness value more accurate. can do.

In addition, it is possible to achieve structural stability without requiring any reaction force.

In addition, it is lightweight and small, can be carried with one hand, can improve work efficiency, and is extremely easy to operate, and can easily collect data at many points in a short time and process data on the spot so that if there is a shortage, it can be immediately used. The consolidation work can be resumed. In addition, since the flooring plate is provided on the outer periphery of the lower end of the hammer guide, the hammer guide can be used by standing on the ground without inclination, and it is easy to work. Since it is a non-destructive test that can be carried out even in a narrow space and does not collect the ground at the site, it is a highly practical device that has many excellent effects suitable for backfill management, such as not damaging the road surface by measurement.

[Brief description of drawings]

 The attached drawing is a side view of a longitudinal section of a tester of the present invention. 1 ... Hammer guide, 2 ... Hammer, 3 ... Floor board, 4 ... Impact sensor, 6 ... Rod, 11 ... Detection / calculation device

Claims (1)

[Scope of utility model registration request] 1. A hollow structure in which a hammer having a flat hammering surface fixed to the lower end of a hammer support is loosely inserted into a cylindrical hammer guide having a floor plate at the lower end, and a handle is attached to the upper end. The rod is fixedly installed on the upper surface of the hammer support, and the hammer is artificially pulled up to a predetermined height, or is released so as to fall naturally. An earth backfill hardness tester in which an impact sensor or a load cell is held between the two, and the impact sensor and the detection calculation device are connected via a coaxial cable through the hollow rod.