JPH10195859A - Automatic penetration test machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately provide the stratum information by placing a penetration unit of a ground strength measuring automatic penetration test machine into the ground, and detecting the penetrated variable with a detecting device such as an encoder, and converting the detected penetrated variable to the electrical signal so as to compute the ratio of the number of driving with the penetrated variable. SOLUTION: An automatic penetration test machine for measuring ground strength before construction for building a residence penetrates a penetration unit thereof into the ground, and while detects the penetrated variable, and computes the ratio of the number of driving with the penetrated variable with an automatic processing device. The penetration unit is formed of a rod 1 and a cone 2, and the rod 1 is placed into the ground by a placing device provided with a driving device. Penetrated variable of the rod 1, is obtained by reading the rotated variable of a rotary unit, the which is formed of a wheel 5 provided so as to contact with the rod 1, with an encoder, and counting the number of pulse corresponding to the rotated variable. Number of times of driving is detected by deciding that placing is performed one time when a response is not generated for the predetermined time after the electrical signal is generated from the encoder 15. Bearing capacity of soil is determined on the basis of the measured penetrated variable and the number of driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic penetration tester for easily measuring the strength of a ground, for example, before a house construction work.

[0002]

2. Description of the Related Art In the construction of a house, in order to ensure that the house is built safely, measurements such as ground bearing capacity are performed in advance. In this survey, the hardness of soil and the degree of compaction are known, and the foundation of houses and the like is set.
As a conventional automatic penetration tester for measuring ground strength, etc.,
Japanese Patent Publication No. 2-58404 discloses that
A test machine for measuring the bearing capacity from the penetration amount is disclosed. The testing machine is configured to bring a rotating foil into close contact with a penetrating rod, send a rotation amount corresponding to the penetration amount to a recording device through a universal joint, rotate the drum around which the recording paper is wound in the recording device, and move the recording paper on the moving recording paper. In addition, a line for movement is recorded with a ballpoint pen, and a dividing line is recorded to make it easy to see the number of hits according to five hits. When the on-site measurement is completed, the dividing line on the recording paper every five times is visually read, and the ground strength is measured by a predetermined formula.

[0003]

However, since such a conventional automatic penetration tester uses recording paper, it is necessary to read the penetration amount from the recording paper. Therefore, in order to analyze the penetration amount, the measurement must be completed, and the penetration amount cannot be quantitatively measured. Further, since the measurement result is visually read by a person, the measurement error may inevitably increase. In particular, when the ground is hard and the amount of penetration is small, reading becomes difficult, and the measurement error increases. Furthermore, in one penetration test, the number of hits at the penetration portion is hundreds of times, which imposes great labor and time constraints on the person reading the measurement result.

An object of the present invention is to solve the above-mentioned conventional problems. It is an object of the present invention to convert the amount of penetration into the ground of an intrusion into an electric signal, and to use a signal processing device to perform the number of hits and the amount of penetration. It is an object of the present invention to provide an automatic penetration tester for automatically determining the ratio of the ground or the bearing capacity.

[0005]

According to one aspect of the present invention, there is provided an automatic penetrating tester, comprising: a penetrating portion; a driving device for hitting the penetrating portion to penetrate into the ground; By detecting the amount of penetration into the ground, a detection device that converts and outputs the electric signal, by processing the electric signal,
This is a structure including a signal processing device for calculating a ratio between the number of hits and the amount of penetration.

Here, the penetrating portion is made of a rod-shaped member, and it is preferable to sharpen the tip so that it can easily enter the ground, and the material is preferably metal. In addition, it is preferable to be able to replenish so that it can penetrate deep into the ground. The driving device drives the penetrating portion in a substantially vertical direction, and can hit a plurality of times with a constant force. There are various methods for driving, such as a method using a free fall of a weight and a method using a hydraulic cylinder to forcibly apply a force to a penetration portion.
The detection device detects how much the penetration portion has penetrated by hitting, and includes a method of detecting by an encoder, a method of reading coordinates without contact, and the like. It is preferable to use an encoder because the configuration of the tester is simplified. The signal processing device is preferably a computer, and particularly preferably a notebook type so as to be easily carried. Separately, it may be provided integrally with the automatic penetration tester. In calculating the ratio, the ratio may be obtained for each impact, or the ratio may be obtained for a plurality of impacts.

An automatic penetration tester according to a second aspect of the present invention is the automatic penetration tester according to the first aspect, wherein the signal processing device calculates ground strength from a ratio between the number of hits and the amount of penetration. It is. The calculation of the earth bearing capacity is obtained by substituting the value of the obtained ratio into a conversion formula given in advance.

According to a third aspect of the present invention, there is provided an automatic penetration tester according to the first or second aspect, wherein the detection device is constituted by an encoder. Here, as a method of installing the encoder, for example, there is a method of providing a rotating portion that comes into contact with the penetrating portion and rotates with the penetration of the penetrating portion, and attaches the encoder to a shaft of the rotating portion.

According to a fourth aspect of the present invention, there is provided an automatic penetration testing machine according to any one of the first to third aspects, wherein the signal processing device collects measurement results at a plurality of penetration locations and simultaneously acquires a plurality of measurement results. The ratio of the number of hits and the amount of penetration at the measurement point or the ground strength is simultaneously displayed. Here, results obtained from a plurality of measurement points are displayed on the same screen so that the conditions of a plurality of strata can be compared at a glance.

[0010]

According to the configuration of the automatic penetration tester according to the first aspect, the penetration amount is detected while the penetration portion penetrates into the ground. Thereafter, the signal processing device automatically calculates the ratio between the number of hits and the amount of penetration.

According to the configuration of the automatic penetration tester according to the second aspect, the penetration amount is detected while penetrating the penetration portion into the ground, and then the ratio of the number of impacts to the penetration amount is automatically detected by the signal processing device. From this, the bearing capacity is calculated.

According to the configuration of the automatic penetration testing machine according to the third aspect, the penetration amount of the penetration portion is detected by the encoder. According to the configuration of the automatic penetration tester according to the fourth aspect, the ratio of the number of impacts and the penetration amount at a plurality of measurement points or the earth bearing capacity is simultaneously displayed, and the conditions of the plurality of formations can be compared at a glance.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, FIG. 1 is a side view of the automatic penetration tester of the present invention viewed from the side. FIG. 2 is a front view of the automatic penetration tester of the present invention as viewed from the front.

In the drawing, the penetrating portion comprises a rod 1 and a slightly thicker cone 2 loaded at the rod tip. The rod 1 is driven into the ground by a driving device provided with a sprocket 3, a chain 4 wound around the sprocket 3, and a drive device configured to open the chain 4 at regular intervals. The amount of penetration of the rod 1 is measured by reading the amount of rotation of a rotating part composed of the foil 5 provided in contact with the rod 1 with an angle detection encoder 15. The driving device includes, for example, a power mechanism such as a motor, which drives the sprocket 3 to operate the driving device connected to the chain 4 so that the rod 1 penetrates into the ground.

[0015] The driving device includes a column 7, a guide rod 8,
It comprises a hammer 9 and a knocking head 10. A support 11 for supporting the driving device is provided below the support 7.
Is provided. Guide arms 12 and 13 are fixedly attached to the column 7 so as to project outward. Lower guide arm 1
2, a rod 1 having a cone loaded at its tip is vertically inserted and held, and a guide rod having a knocking head fixedly mounted at its lower end is inserted and held in the upper guide arm 13, and is knocked above the rod 1. The head 10 is mounted. A vertically movable hammer 9 is fitted on the knocking head 10, and the hammer 9 can move up and down in accordance with the movement of the chain 4.
Attached to. In the vicinity of the penetrating portion of the rod 1, the wheel 5 of the rotating portion is in contact with the guide roll 14 so as to sandwich the rod 1.

The signal processing apparatus includes, for example, a notebook computer 6 used in the embodiment, which is composed of a computer and a display. The notebook computer 6 converts the electric signal from the encoder 15 as a detecting device into a notebook computer 6.
Received by the counter board connected to In this case, the number of pulses output according to the rotation amount is counted (1
By setting the pulse to 2 mm in the case of the embodiment, the penetration amount is measured. Also, as an example of another detection device, if an absolute type encoder is used, it is possible to use a digital board to measure the absolute rotation amount after rotation is completed, instead of the relative value such as the number of pulses from the previous position it can. The method of detecting the driving is to detect the driving once if there is no response for a predetermined time after the generation of the electric signal from the encoder 15. In addition, there are a method of installing an acceleration sensor or the like on the rod 1 and sensing the impact of a drop, and a method of monitoring a rotating part and using its trigger.

Then, an Ns value for judging ground bearing strength is first calculated from the measured penetration amount and the number of impacts. Note that the Ns value refers to the number of hits required to drive the penetrating portion 100 cm, and is given by the following equation. Ns value = (100 / penetration amount) × number of hits However, 100 cm driving means that the same stratum as the stratum at the penetrating portion is uniformly 100 cm, and the stratum having a uniform stratum is not less than 100 cm. It does not mean that. In the embodiment, since the Ns value is automatically obtained for each hit, the Ns value is (10
0/1 penetration). Further, by substituting this Ns value into a conversion formula obtained in advance,
Earth bearing capacity is calculated. The calculation result of the Ns value or the earth bearing capacity is displayed in a graph on a display.

Next, the case of comparing a plurality of penetration test results will be described below. For the first point in the same site, measurement is performed as described above. Then, after the second point, a graph of the Ns value of the previous point or a point before it (all points are of course also possible) or a graph of the soil strength is displayed on the display, and the data at the current measurement point is measured. A graph of a new Ns value or soil bearing capacity is overwritten on the graph. FIG. 3 shows a graph of the measurement results obtained by the automatic penetration tester of the present invention. 1 shown in the graph indicates the Ns value of the point measured first. Similarly, 2 is the Ns value of the second measured point.

Next, the shape of the cone 2 will be described with reference to FIG. The cone 2 is attached to the tip of the rod 1 and penetrates into the ground, and has two types of shapes, one of which is a conical shape having a tip angle of 60 degrees and an external shape of 3 cm (A-type cone). ) And the other one is a sharp cone (B-type cone) having a tip angle of 30 degrees and an outer diameter of 3 cm. The nature of the stratum can be accurately determined by the difference in the degree of penetration of the cone. The rod 1 holding the cone 2 has an outer diameter of 19 m.
It can be added or disassembled every 1 m with an iron bar of m. In addition, when the work of adding the lot 1 is performed, there is a high possibility that the wheel 5 will rotate. Therefore, the signal processing device automatically monitors whether or not the penetration operation is being performed. The amount of rotation of the wheel 5 is set to the amount of penetration this time. The hammer 9 that moves the guide rod 8 up and down has a weight of 8.9 kg and falls about 50 cm between the upper guide arm and the knocking head 10.

[0020]

According to the configuration of the automatic penetration tester according to the first aspect, the ratio between the number of hits and the amount of penetration is easily calculated on the spot by the signal processing device, so that the measurer requires a great deal of labor and effort. There is no time constraint. Further, there is no possibility that a measurement error or a calculation error occurs, and more accurate information on the formation can be obtained.

According to the configuration of the automatic penetration tester according to the second aspect, since the ground strength is easily calculated on the spot by the signal processing device, a great deal of labor and time constraint are not imposed on the measurer. . Further, there is no possibility that a measurement error or a calculation error occurs, and more accurate information on the formation can be obtained.

According to the configuration of the automatic penetration tester according to the third aspect, since the encoder is used for the detecting device, the structure is simplified, and the maintenance of the automatic penetration tester becomes easy.

According to the configuration of the automatic penetration tester according to the fourth aspect, since the comparison of the measurement results at each measurement point can be easily and promptly made on the spot, it is necessary to increase the number of inspection points on the spot. Can be determined. For example, in a survey of ordinary residential land, three or five points on the diagonal line in the site are measured, but if the bearing capacity for the depth obtained at each measurement point is different, increase the number of measurement points further. It is necessary to estimate the formation status. Therefore, in the apparatus of the present invention, data comparison at each measurement point can be performed immediately at the survey site, and the determination can be made on the spot.

[Brief description of the drawings]

FIG. 1 is a side view of an automatic penetration tester of the present invention as viewed from the side.

FIG. 2 is a front view of the automatic penetration tester of the present invention as viewed from the front.

FIG. 3 is a graph showing measurement results obtained by the automatic penetration tester of the present invention.

FIG. 4 is a front view of a cone of the automatic penetration tester of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rod (penetration part) 2 Cone (penetration part) 3 Sprocket 4 Chain 5 Wheel 6 Laptop (signal processing device) 7 Prop (drive device) 8 Guide rod (drive device) 9 Hammer (drive device) 10 Knocking head (drive) 11) Support 12 Lower guide arm 13 Upper guide arm 14 Guide roll 15 Encoder (detection device)

Claims (4)

[Claims] A penetrating portion, a driving device for hitting the penetrating portion to penetrate the ground, a detecting device for detecting an amount of the penetrating portion penetrating into the ground, converting the amount of the penetrating portion into the ground, and outputting the electric signal. An automatic penetration tester comprising: a signal processing device that calculates a ratio between the number of hits and the amount of penetration by processing the electric signal. 2. The automatic penetration tester according to claim 1, wherein the signal processing device calculates a ground strength from a ratio between the number of impacts and a penetration amount. 3. The apparatus according to claim 1, wherein said detecting device is an encoder.
Or the automatic penetration tester according to 2. 4. The signal processing device according to claim 1, further comprising: collecting measurement results at a plurality of measurement points, and simultaneously displaying a ratio of the number of hits to the plurality of measurement points and a penetration amount or a ground bearing capacity. Automatic penetration tester.